FILE COPY
A STANDARD FOR
TRITIUM
A recommendation
to the Minister
of the
Environment and Energy
AŒS
Advisory
Committee
on Environmental
Standards
Comité
consultatif
sur les normes
environnmentales
A STANDARD FOR
TRITIUM
A recommendation
to the Minister
of the
Environment and Energy
ACES Report 94-01
May, 1994
ISBN: 0-7778-2979-7
Executive Summary
On December 16, 1993, The Honourable C.J. (Bud) Wildman, Minister of the
Environment and Energy, wrote to the Advisory Committee on Environmental
Standards (ACES) and requested that ACES conduct a public consultation on the
Ministry's proposed Interim Ontario Drinking Water Objective (ODWO) for tritium of
7,000 Becquerels per litre (Bq/L). This referral arose as a result of public concern
about a plan to expand the existing water supply plant in Ajax, Ontario. This plant
would draw raw water from Lake Ontario and is adjacent to the Pickering Nuclear
Power Generating Station (PNGS), which discharges tritium in waste water into the
lake.
Tritium is a radioactive form of hydrogen. It is long lasting, with a radioactive half-
life of 12.3 years and a biological half-iife of 10 days to 2 years. Tritium occurs
naturally, but the majority of tritium in Lake Ontario is a byproduct of CANDU
nuclear reactor operations. Conventional water treatment is not able to remove tritium
from drinking water as it passes through the water treatment plant. The only practical
way to reduce tritium levels entering surface waters drawn by water treatment plants is
to reduce emissions from CANDU nuclear facilities.
ACES invited public comment on the proposed ODWO by using a large mailing list
and by advertising in newspapers. Respondents were sent a copy of the Ministry's
Rationale Document for the Development of an Interim Ontario Drinking Water
Objective for Tritium (MOEE 1993) and were asked to comment on it. Public interest
in this issue was widespread and resulted in new information not contained in the
Rationale Document being brought to the attention of ACES. For example, ACES
learned that readers of the Rationale Document would probably underestimate the fatal
cancer risk posed by the proposed ODWO. The Ontario Ministry of the Environment
and Energy's (MOEE) policy on Drinking Water Objectives states that lifelong
exposure (estimated to be 70 years) must be considered. The documents used in
deriving the ODWO for tritium, however, consider exposure for only one year.
Although this approach has often been taken by nuclear regulatory agencies, it is
clearly at odds with MOEE' s policy on drinking water guidelines. Exposure to 7,000
Bq/L represents a risk of approximately 340 excess fatal cancers per million people
exposed over their entire lives.
In many regulatory agencies, including MOEE, 1 excess cancer per million people
exposed is often considered acceptable if there are multiple media for exposure to a
given contaminant and a large population is affected. A higher level of acceptable risk
of 1 excess cancer per hundred thousand people exposed is often used to derive
standards when small populations are affected, and their exposure results from only a
single medium. Exposure to tritium in Ontario occurs through drinking water and the
affected population may be large. Exposure may also occur via air and perhaps, food.
Therefore, ACES recommends that an acceptable level of risk for excess cancers due
to exposure to tritium be 5 per million people at risk, as suggested by the MOEE in
the Rationale document. Given a 70 year (lifelong) exposure, and assuming the annual
risk is additive, this would result in an Ontario Drinking Water Objective of 100
Bq/L.
There are many other sources of uncertainty and concern which were brought to the
attention of ACES by members of the public during this consultation. For example,
the risk calculations do not directly address non-fatal cancers nor health effects other
than cancer, and there is scientific uncertainty regarding the relative biological
effectiveness of tritium. Some members of the public also expressed concern that the
most sensitive subpopulation (the developing fetus) was not considered in the risk
calculation. For these reasons, ACES recommends that the ODWO for tritium be
reduced over time to 20 Bq/L, corresponding to an acceptable level of risk of 1 excess
cancer per million people following lifelong exposure. Several members of the public
pointed out that tritium would meet the International Joint Commission's (DC)
definition of a persistent toxic substance and, on that basis, should be virtually
eliminated from industrial discharges. Some respondents pointed out that on the basis
of the IJC's recent Seventh Biennial report, tritium should be considered a candidate
for "zero discharge". Others suggested that tritium be added to Ontario's Priority
Pollutants List as it is a known carcinogen which is discharged into Provincial surface
waters. ACES endorses these principles and recommends that discussions should be
initiated with Ontario Hydro and AECL regarding the feasibility of reducing tritium
emission levels from nuclear facilities in Ontario.
ACES consulted the public on the proposed Interim ODWO of 7,000 Bq/L and the
feasibility of achieving this level. ACES is not aware of comprehensive information on
the feasibility of achieving the lower recommended level of 100 Bq/L, nor was this
issue addressed in the MOEE's Rationale Document. However, the monitoring data
available through the Ministry's Drinking Water Surveillance Program (DWSP)
suggest that 100 Bq/L is rarely exceeded. Therefore, it is a currently achievable
standard which will only become more readily achievable as background levels of
tritium decline due to the decay of nuclear fallout from atmospheric weapons testing.
The same monitoring data indicate that 20 Bq/L is not currently a routinely achievable
standard in drinking water near nuclear facilities. Because conventional water
treatment does not remove tritium, ACES recommends that feasibility studies be
undertaken with the goal of reducing tritium emissions sufficiently to permit the
ODWO to be lowered to 20 Bq/L within 5 years.
In conclusion, ACES recommends that the Ontario Drinking Water Objective for
Tritium be set immediately at 100 Bq/L. ACES further recommends that, due to the
fact that tritium is a human carcinogen and because of the many uncertainties in the
risk assessment, the tolerable level of tritium in drinking water be reduced to 20 Bq/L
in 5 years with the goal of further reduction as human contributions to tritium
background levels decline. The five year schedule for the reduction acknowledges the
need for technical and financial feasibility studies on the ODWO of 20 Bq/L. In
addition, ACES recommends that this standard be applied as a health-based Maximum
Acceptable Concentration, so that when the drinking water standard is exceeded, an
alternative water supply should be made available.
Table of Contents Pa8e
Executive Summary •
Referral 1
Recommendation for an Interim
Ontario Drinking Water Objective
for Tritium *
List of Acronyms 2
Glossary 4
Background
Public Health Significance 8
What is Tritium? 8
Sources of Exposure to Tritium 8
Routes of Exposure
Exposure Pathways 9
Adverse Health Effects of Tritium 10
The Tritium Challenge 1°
Internal Review H
Public Consultation Process 12
Review of Public Comment I4
Overview of Public Response 15
Exposure 1°
Risk 17
Feasibility
Implementation 23
Need for Additional Studies 26
Other Comments and Recommendations 27
Summary of Recommendations 28
References
30
Appendices
1 Background Material on Tritium 32
2 List of Respondents in ACES' s Public Consultation on Tritium 39
3 Summary Tables of Public Comments 43
4 Letter from Dr. Waight, Health Canada 85
5 U.S. EPA's Science Advisory Board paper entitled
Harmonizing Chemical and Radiation Risk Reduction
Strategies-A Science Advisory Board Commentary 87
6 Table 2: The Effect of Various Issues on the Recommended
ODWO 101
7 1991 Tritium Data from the Nuclear Surveillance Program and
Analysis of Tritium in Drinking Water 102
Referral
On December 16, 1993, the Honourable C.J. (Bud) Wildman, Minister of the
Environment and Energy, requested that the Advisory Committee on Environmental
Standards (ACES) consult with the public on the Ministry of the Environment and
Energy's proposed Interim Ontario Drinking Water Objective (ODWO) of 7,000
Becquerels per litre (Bq/L) for the radionuclide tritium in drinking water. ACES was
requested to review and provide recommendations on the proposed Interim Ontario
Drinking Water Objective.
Recommendation
for an Interim
Ontario
Drinking Water
Objective for
Tritium
ACES recommends that the Ontario Drinking Water Objective for Tritium be set
immediately at 100 Bq/L. ACES further recommends that, due to the fact that tritium
is a human carcinogen and because of the many uncertainties in the risk assessment,
the tolerable level of tritium in drinking water be reduced to 20 Bq/L in 5 years with
the goal of further reduction as human contributions to tritium background levels
decline. The five year schedule for the reduction acknowledges the need for technical
and financial feasibility studies on the ODWO of 20 Bq/L. In addition, ACES
recommends that this standard be applied as a health-based Maximum Acceptable
Concentration, so that when this drinking water standard is exceeded, an alternative
water supply should be made available.
List of Acronyms
ACES Advisory Committee on Environmental Standards
Atomic Energy Control Board
Atomic Energy of Canada Limited
AECB
AECL
BEIR
The U.S. National Research Council's Committee on Biological Effects of
Ionizing Radiation
Bq Becquerel
CDWG Canadian Drinking Water Guidelines
CANDU CANadian Deuterium Uranium (the type of nuclear reactors used in Canada)
DWSP Drinking Water Surveillance Program
EAAC Environmental Assessment Advisory Committee
*H Tritium (Hydrogen 3)
DEL Derived Emission Limit
ICRP International Commission on Radiological Protection
UC International Joint Commission
MAC Maximum Acceptable Concentration
MOEE Ministry of the Environment and Energy
MOL Ministry of Labour
mSv Millisievert
NCRP National Council on Radiation Protection and Measurements (US)
NGS Nuclear Generating Station
ODWO Ontario Drinking Water Objectives
OWRA Ontario Water Resources Act
OBT Organically Bound Tritium
RBE Relative Biological Effectiveness
UNSCEAR United Nations Scientific Committee on the Effects of Atomic Radiation
U.S. EPA United States Environmental Protection Agency
WHO World Health Organization
WSP Water Supply Plant
Glossary
Activity:
The rate of decay (i.e. number of disintegrations or transformations per unit time) of a
radioactive nuclide. The international unit of activity is the becquerel (Bq).
Background Radiation:
The amount of radiation to which a member of the population is exposed from natural
sources including terrestrial radiation due to naturally occurring radionuclides in the
soil and cosmic radiation originating in outer space. The main contributing factor to
what is now referred to as "background" tritium levels is fallout from atmospheric
nuclear weapons testing.
Beta Particles:
Fast moving electrons ejected from the nuclei of certain unstable radioactive atoms
(e.g. tritium). Beta particles are not densely ionizing.
Becquerel (Bq):
International unit of measurement of the activity of a radioactive nuclide. One
becquerel corresponds to one atomic transformation or disintegration per second and is
equivalent to 2.7 x 10"" Curies.
Carcinogen:
An agent that can cause cancer. Ionizing radiation is a carcinogen. Tritium, which
emits ionizing radiation, is a carcinogen.
Committed Effective Dose:
The effective dose that will be accumulated over 70 years following a single intake of
radioactive material into the body.
Curie (Ci):
A unit of activity equal to 3.7 x 1010 disintegrations per second.
Dose Equivalent:
A measurement that relates absorbed dose with the biological effectiveness (i.e.
probability of causing biological damage) of various kinds of ionizing radiation. Dose
equivalents are calculated by multiplying the absorbed dose by a quality factor that
accounts for differences between different types of radiation. The international unit of
dose equivalents is the sievert (Sv).
Gray:
The SI unit of absorbed dose where one gray equals one joule per kilogram, and one
gray equals 100 rad.
Half-Life:
The time taken for the activity of a radionuclide to lose half its value by decay.
Ionizing Radiation:
Radiation that is capable of producing ions (particles with an electric charge) by
dislodging electrons from an atom.
Maximum Acceptable Concentration (MAC):
A MAC is a type of Drinking Water Objective that is established for certain
substances that are known or suspected to cause adverse effects on health. Each MAC
has been derived to safeguard health assuming lifelong consumption of drinking water
containing the substance at that concentration.
Multimedia:
A multimedia assessment considers how a contaminant released to one medium (air,
water, soil or sediment) may move to or impact other media. This approach also
considers all human exposure routes including food, water, air and soil.
Organically Bound Tritium (OBT):
Tritium is bound organically either in exchange reactions or into stable bonds to
carbon atoms only via enzymatically catalyzed reactions in which it replaces hydrogen.
Tritiated organic matter is classified as a function of the fractions of the exchangeable
and non-exchangeable bound tritium it contains, e.g. organic compounds that
incorporate radioactive tritium in place of hydrogen, vegetable food and animal foods
around Nuclear Generating Stations have higher OBT concentrations.
Rad:
A unit of absorbed dose, now replaced in international units by the gray, where one
rad equals 0.01 gray.
Radioactivity:
The spontaneous emission of radiation, in the form of alpha particles, beta particles,
etc.
Radionuclide:
An unstable nuclide that emits ionizing radiation
Relative Biological Effectiveness (RBE):
The biological potency of one type of radiation as compared with another to produce
equivalent biological damage.
Rem:
A measure of dose equivalent (1 rem = 0.01 Sv).
Standard:
The term "standard" in this report includes interim standards, objectives, guidelines,
and any other form of limitation which specify a tolerable level for environmental
contaminants.
Sievert:
The SI unit of measure defined as the quantity of absorbed radiation that induces the
same biological effect in a specified tissue as 1 gray of high-energy x-rays; 1 sievert
= 100 rem or 1000 millisieverts. A sievert is used as an international unit of dose
equivalents. The quantity is obtained by multiplying the dose equivalents to various
tissues and organs by the risk weighting factor appropriate to each organ and summing
the products.
Background
In 1990 the Region of Durham approved a recommendation to enlarge the existing
water supply plant in Ajax to address the need for additional water supplies.
In 1992 the Minister of the Environment at the time, Ruth Grier, asked the
Environmental Assessment Advisory Committee (EAAC) for advice on whether an
individual environmental assessment should be required for the proposed water supply
plant.
In its report to the Minister, the EAAC recommended against an individual
environmental assessment for the proposed plant provided that certain
recommendations were appropriately addressed.
With respect to concerns raised about tritium concentrations in drinking water due to
the water supply plant's close proximity to the Pickering Nuclear Generating Station,
EAAC recommended that the Minister request that the Advisory Committee on
Environmental Standards (ACES) carry out a public review and advise the Minister on
an appropriate standard for tritium in drinking water.
The Ministry of the Environment and Energy's Standards Development Branch
produced the Rationale Document for the Development of an Interim Ontario Drinking
Water Objective for Tritium (MOEE 1993). The Minister then requested that ACES
carry out a public consultation on the Interim ODWO for tritium proposed in the
Rationale Document.
Public Health
Significance
What is
Tritium?
Tritium is a radioactive isotope of hydrogen. It has a half-life of 12.3 years (the
amount of time it takes one half of a quantity of tritium to decay into non-radioactive
helium). The biological half-life of tritium (the amount of time the body requires to
excrete one half of the tritium absorbed) ranges between 10 days and two years,
depending on its location in the body.
Tritium is a by-product of Canadian Deuterium Uranium (CANDU) nuclear reactor
operations and it also occurs naturally. Tritium is produced in CANDU reactors
through the absorption of a neutron into a deuterium atom in heavy water, which is
used as a moderator and coolant. During reactor operation, a small fraction of the
deuterium molecules in the heavy water take on an additional neutron and thus they
become radioactive tritium (3H). The resulting tritiated water is regularly discharged
from these reactors. Radioactive tritium* (3H) decays to non-radioactive helium (3He)
and emits a negatively charged beta particle (P~).
The decay formula is as follows:
^ -> ^e + p"
This weak beta-emitter is used commercially as a light source in flares, emergency
lights, exit signs, and luminous dials. It also has uses in medical research. As well as
being an essential fuel for nuclear fusion, tritium can be used in nuclear weapons
production.
Sources of
Exposure to
Tritium
Today, the main source of tritium released into the Canadian environment in air and
water emissions is nuclear energy production facilities. In particular, the CANDU type
water-cooled reactors used by Ontario Hydro, representing the largest Canadian point
source of tritium, release tritium both operationally and accidentally.
"When "tritium" is used in this report it refers to tritiated water, unless otherwise
specified.
The majority of tritium exposure is the result of human activities. Tritium is produced
in nuclear explosions. Fallout from thermonuclear weapons testing, begun in the
1940s, is a source of tritium in the global environment. A very large quantity of
tritium has been released from these activities, resulting in a sharp increase in the
tritium content of rain water and atmospheric tritium. This was the main contributing
factor to a rise in what is now referred to as "background" tritium levels. In recent
years background levels of tritium have declined, reflecting the cessation of
atmospheric nuclear testing and the decay of tritium over time from these explosions.
In nature, tritium is produced by the interaction of cosmic rays with molecules of
nitrogen, oxygen and argon in the upper atmosphere. It is converted into tritiated
water and precipitated into the global water cycle. Natural sources of tritium account
for less than 1 % of tritium exposure.
Routes
of
Exposure
Once released to the environment, tritium exposure to humans can occur from a
variety of routes, namely via water, air, and food. Exposure to water-borne releases
can occur through the consumption of drinking water supplies or through other water
contact, e.g., swimming, bathing, showering, etc.
Air-borne tritium is also a source of exposure to communities around nuclear
generating stations. Air-borne releases of tritium contaminate ambient air and can
settle on surface waters and agricultural lands.
Exposure
Pathways
Tritium can be taken into the body by inhalation, absorption through the skin, or
ingestion. Tritium entering the body by inhalation is normally distributed uniformly
among all the soft tissues in the body.
The absorption of tritiated water through the skin is a pathway of human exposure.
Bathing, showering or recreational activities are examples of human dermal exposure
routes.
Following ingestion, tritiated water is absorbed immediately from the gastrointestinal
tract and then mixes rapidly with the total body water. In addition, ingestion of
contaminated foods is a potential exposure pathway from air-borne tritium emissions.
The ingestion of contaminated fruits, vegetables or food animal products raised near
nuclear generating stations may be a significant source of organically bound tritium
(OBT), i.e., organic compounds that incorporate radioactive tritium in place of normal
hydrogen.
Adverse
Health
Effects of
Tritium
Tritium is classified as a human carcinogen by the United States Environmental
Protection Agency. There is no safe exposure level for any form of ionizing
radiation. Low doses of radiation are known to cause genetic damage in living cells.
Where reproductive cells are affected by radiation, mutations may occur and adverse
effects may manifest in offspring.
Exposure to radiation may also result in the development of cancer. A cancer may
occur at any dose of ionizing radiation.
The
Tritium
Challenge
The connection between tritium emissions from nuclear facilities and tritium levels in
drinking water is critical. Levels of tritium in drinking water in excess of background
are the result of emissions from nuclear facilities. Ontario Hydro, in their report
entitled "Annual Summary and Assessment of Environmental Radiological Data for
1991", state that "Tritium concentrations in drinking water taken from Lake Ontario at
the Ajax, Whitby, Oshawa, Scarborough and Toronto (Harris) plants exceeded the
Lake Ontario average of 8.7 Bq/L due to emissions to water at the Pickering
generating stations." Conventional water treatment is unable to remove tritium from
drinking water supplies. Therefore, significant reductions in tritium levels in surface
waters, which are a drinking water source, can only be achieved by additional
emission controls at nuclear facilities.
10
Internal
Review
Upon receipt of the Rationale Document from the Ministry, ACES undertook its own
internal review. ACES concluded that the material presented in the Rationale
Document (MOEE 1993) was adequate to proceed with public consultation, but ACES
noted the absence of a scientific criteria document. ACES requested that the key
references used in the development of the Rationale Document be compiled by the
MOEE, and these documents were provided by ACES for public review during the
consultation.
11
Public
Consultation
Process
ACES undertook a public consultation on a drinking water standard for tritium which
involved several methods of reaching out to the interested public. These included
mailing a consultation package to ACES' s general mailing list, advertising in
newspapers and magazines and holding public information meetings in the
Ajax/Pickering area. ACES' s general mailing list was compiled from several mailing
lists provided by the Ministry of the Environment and from individuals or
organizations who had expressed interest in ACES' s previous consultations. A
targeted list composed of additional groups who were thought to have a particular
interest in this consultation was generated. They included: industrial groups,
environmental organizations, labour unions, and Ajax/Pickering area residents/groups.
A package of background material (see Appendix 1) was prepared including:
-a cover letter describing the consultation;
-a copy of the advertisement that appeared in newspapers (which included the
questions being posed);
-a list of the background documents used in the development of the proposed
tritium standard and their locations for review;
-a copy of the News Release describing the referral of the tritium standard to
ACES;
-a "Backgrounder" on tritium prepared by the Ministry of the Environment and
Energy;
-information on the concurrent ACES public consultation on the proposed
multimedia standards for lead.
Everyone was provided with a postage paid return envelope to encourage participation.
This package was sent to approximately 6,600 people between January 10, 1994 and
January 14, 1994.
The questions posed were as follows:
1 . Is the proposed standard acceptable?
2. If not, what is the basis for finding the proposed level unacceptable?
3. Do you have an alternative level to propose?
Additional comments were also encouraged.
A second mail out was sent to 330 individuals and organizations who had been
identified as having a special interest in the review of tritium but who had not
responded to the first mail out after 28 days had elapsed.
12
In order to reach members of the potentially interested public who might not be on the
mailing list, an advertisement, which included the above questions, appeared once in
the Globe and Mail and in each of 19 newspapers in communities located near nuclear
generating stations or other nuclear facilities during the week of January 10 to January
14, 1994. An advertisement also appeared in the Ontario Gazette on January 8, 1994
and on the Web Network on January 10, 1994. (The Web Network is a
communication network to which many different organizations, including many
environmental groups from around the world, subscribe.)
A package of supporting documentation was made available for review at the ACES
Office in Toronto and at the Town of Ajax Clerk's office (see page 2 of Appendix 1).
A public information session was held on January 27, 1994 in Ajax, Ontario in order
to explain ACES' s public consultation process and to allow the Ministry of the
Environment and Energy to provide the rationale for the development of the standard.
An announcement of the meeting was included in the mail out packages and an
advertisement outlining the times and location of the meeting was placed in 4 Ajax
area newspapers. In order to make the meeting as accessible as possible to those who
wished to attend, there were two times scheduled for this meeting, one in the
afternoon and one in the evening. ACES ensured that the meeting room was wheel
chair accessible and an audio technician provided amplification to the participants to
facilitate hearing. A summary of the presentations was also provided in poster form
outside the meeting room. These meetings were tape recorded and written transcripts
were made available upon request. Approximately 100 copies of the transcripts were
requested. In addition, the evening session of the meeting was video taped by
MacLean Hunter Cable television and aired at least 8 times over the month of
February, 1994.
Requests for oral deputations were received until February 7, 1994. A deputation
session was held in Pickering on February 16, 1994, at which seven presenters made
oral submissions to ACES. A second deputation session was held via teleconference
on February 28, 1994, in which four presenters participated. This was the first time
that ACES undertook a teleconference deputation, which permitted presenters from
across the Province to make oral presentations to the Committee without travelling
long distances. ACES felt that the consultation on the proposed Interim ODWO for
tritium was effective and efficient, in part as a result of the combination of targeted
advertisements and other audio-visual techniques.
The deadline for the public to send written responses on the proposed ODWO for
tritium was March 10, 1994.
13
Review of
Public
Comment
A total of 226 requests for additional information were received in response to the
initial mail out and advertisements. These respondents were sent the Rationale
Document for the Development of an Interim Ontario Drinking Water Objective for
Tritium (MOEE 1993).
A total of 84 written responses were received and 1 1 deputation presentations were
made dealing with various aspects of the rationale for setting an Interim ODWO of
7,000 Bq/L for tritium. A list of respondents is attached as Appendix 2.
In reviewing the comments submitted, every response was considered carefully.
Comments ranged from short letters on the proposed standard through to detailed
technical submissions. Comment summaries are provided in Appendix 3. All
comments, whether oral or written, received equal consideration. Submissions
received after March 10, 1994, were read and considered, but are not included in this
report.
When analyzing the responses, a number of issues were identified. Many respondents
addressed more than one issue.
These issues were categorized as follows:
Overview of Public Response
Exposure
Risk
Feasibility
Implementation
Need for Additional Studies
Other Comments and Recommendations
14
Overview of
Public Response
The consultation materials distributed posed three questions and encouraged additional
comments. Responses to ACES' s three consultation questions were divided into four
categories depending on how the question regarding the acceptability of the proposed
standard was answered. A summary is presented in Table 1.
Table 1. Summary of Responses Regarding the Proposed Standard
Comment
Number
%
Yes, the proposed standard is acceptable.
17
20
No, the proposed standard is not
acceptable, the level should be lower.
43
51
No, the proposed standard is not
acceptable, the level should be higher.
4
5
Question not answered directly.
20
24
Total comments received
84
100
The proposed standard was deemed acceptable by 17 people. The standard was
deemed unacceptable by 46 respondents, 4 recommending that the level be higher and
42 recommending that the level be lower. The question was not answered directly by
20 respondents.
In addition to responding to these questions, the public provided ACES with
information and supporting documentation of which the Committee had not been
previously aware. This confirmed to ACES the value of the public consultation
process.
15
Exposure
Summary of Public Comment
In response to ACES' s question on the appropriateness of the proposed standard, two
respondents brought to ACES' s attention the fact that the basis of the risk assessment
for tritium differed fundamentally from that for all non-radioactive contaminants. The
entire paradigm, or model, on which risk assessments for radionuclides are based
makes unique assumptions and calculations. The public comment on this issue pointed
out that the lifetime risk associated with environmental radioactive contaminants is
calculated based upon consumption of drinking water containing a radioactive
contaminant every day for only one year. In contrast, the lifetime risk associated with
environmental chemical contaminants is calculated based upon consumption of drinking
water containing a chemical contaminant every day for 70 years (the average life-
span).
Response by ACES
The final draft of the 1993 revision of the Ontario Drinking Water Objectives
document states, in Section 1.2 Types of Objectives, that "Almost all objectives are
based on a 70 kg person consuming 1.5 litres1 of water per day for 70 years (emphasis
added)." Setting an ODWO on a lifetime risk estimate based on only one year's
exposure to a contaminant at a certain level represents a significant departure from this
stated policy.
The proposed tritium level of 7,000 Bq/L represents a lifetime risk of 5 excess cancers
per million people exposed for one year. The MOEE, in proposing 7,000 Bq/L, is
consistent with the international radiation protection community's risk assessment
practices. Lifelong (70 year) exposure to 7,000 Bq/L would result in approximately
340 excess fatal cancers per million people exposed2. ACES considers that the
ODWO for tritium should be lower than the proposed level because the international
radiation protection community based the lifetime risk level on only one year's
exposure. Extending this exposure over a 70 year life-span would add to the lifetime
cancer risk, especially if exposure occurred in one's early years (See further
discussion under Risk).
^e MOEE' s proposed ODWO for tritium assumes a 2.0 litre per day consumption of
drinking water.
2Please refer to the letter in Appendix 4 for the calculation of total lifetime risk of 0.1
mSv received annually for 70 years. This calculation was provided by Dr. P.J.
Waight of the Radiation Protection Bureau of Health Canada.
16
Risk
For the purposes of this review, ACES accepts the international radiation protection
community's derivation of 0.1 mSv in one year from the consumption of 2.0 litres of
drinking water per day as the dose which will result in 5 fatal cancers per million
exposed population. If this dose (i.e., 0.1 mSv) is lifelong (70 years), U.S. EPA
estimates that between 300 - 1000 additional fatal cancers per million exposed would
result.1 The EPA numbers are derived from the BEIR V report which estimates that
520 additional fatal cancers per million exposed males and 600 additional fatal cancers
per million exposed females will result from this lifelong dose (BEER V 1990).
MOEE proposes, in the Rationale Document, that an acceptable level of risk for
tritium in drinking water is 5 excess cancers per million people exposed. Based on
this level of acceptable risk and with lifelong exposure, the following calculation was
performed:
7,000 Bq/L (proposed level for one year's exposure) / 70 years (average life-span) =
100 Bq/L.
An ODWO of 100 Bq/L represents a drinking water standard with an acceptable risk
of 5 excess cancers per million people following lifelong exposure.
Summary of Public Comment
The acceptable risk level of the 5 additional cancers per one million people exposed,
as proposed in the MOEE' s Rationale Document, was challenged by three
respondents. In general, they recommended a de minimus risk of 1 excess cancer per
one million people exposed as a conservative public health approach.
It is possible that many of the respondents were not aware that the cancer risk referred
to in the Rationale Document was the risk following one year's exposure and not a
lifelong exposure (see further discussion under Exposure).
Health effects other than fatal cancer were cited by 16 of the respondents as a
rationale for the lowering of the proposed standard. The public expressed particular
concern about birth defects, non-fatal cancers, childhood leukaemia, effects on
'A paper from the U.S. EPA' s Science Advisory Board entitled Harmonizing Chemical
and Radiation Risk Reduction Strategies-A Science Advisory Board Commentary
discusses the two risk paradigms that have evolved and is found in Appendix 5.
17
immunity, and Down's Syndrome. One member of the public summed up their view
on the use of fatal cancers as the only endpoint of concern by stating that "health is
more than the absence of death". Several respondents referred to the AECB studies
which reported a higher incidence of childhood leukaemia and Down's Syndrome
around nuclear generating stations (Clarke and McLaughlin 1989, Clarke and
McLaughlin 1991, Johnson and Rouleau 1991).
The public cited a number of additional factors which were not considered in the risk
estimates. These factors included: the exposure of sensitive populations (12
commenters), (i.e., fetuses, young children, women of childbearing age, etc.);
synergistic or additive effects of tritium with other contaminants, including
radionuclides, in drinking water (11 commenters); other routes or sources of tritium
exposure (4 commenters); organically bound tritium (3 commenters); the potential for
tritium, particularly organically bound tritium, to bioaccumulate (2 commenters); the
dose conversion factor used (2 commenters); the relative biological effectiveness
(RBE) of tritium (3 commenters); the validity of extrapolating data from acute high
doses to chronic low doses (1 commenter). The respondents generally supported a
much lower standard for tritium in drinking water as a result of these factors.
Two commenters raised the issue of the potential effects on fetuses in utero of periodic
"pulses" of tritium in drinking water. These pulses result from intermittent higher
level tritium emissions. Their concerns centred on the exposure of pregnant women
due to the susceptibility of rapidly dividing embryonic cells to radiation.
The "Petkau effect" was referred to by several respondents and one expressed concern
over its implications for a greater risk of health problems following continuous low
level radiation exposure.
Six respondents raised the issue of the historical risk assessment by international
agencies such as the International Commission on Radiological Protection (ICRP), the
World Health Organization (WHO) and the National Council on Radiation Protection
and Measurements (NCRP). These agencies have reduced the acceptable risk by a
factor of five in their most recent recommendations1. Respondents raised concerns
regarding these agencies past underestimation of the risks associated with radionuclides
and expressed a lack of confidence that these new risk estimates are "correct".
'A revised estimate of the risk of a lifetime fatal cancer for the general population has
been estimated by the International Commission on Radiological Protection (ICRP) to
be 5 x 10"2 per sievert (ICRP 1990). In light of this change, the World Health
Organization revised its reference level of committed effective dose to 0. 1 mSv from 1
year's consumption of drinking water (WHO 1993). This is a five fold reduction from
the WHO'S previous reference level of 0.5 mSv.
18
Of the respondents who recommended a lower level (see Overview of Public
Responses), 16% supported setting the standard at background levels and 51%
supported zero discharge. (Many members of the public recommended zero as the
acceptable level in drinking water. ACES recognizes that the ambient concentration
will never be zero due to the existence of natural sources of tritium contamination and
took the public's support of a drinking water standard of zero to indicate support of
zero discharge). Numerous commenters cited the International Joint Commission's
(JJC) position of virtual elimination of persistent toxins as their rationale. They stated
that the JJC considers radionuclides with half-lives greater than six months as
persistent toxic substances. In its Seventh Biennial Report on Great Lakes Water
Quality (JJC 1994) the JJC suggests, in its Recommendations to Federal and
State/Provincial Governments, that "Governments incorporate those radionuclides
which meet the definition of persistent toxic substances in their strategy for virtual
elimination. "
Six percent of respondents went on to recommend staged reduction levels with precise
time lines to reflect the decrease in background tritium levels as a result of the decay
of tritium from weapons testing over time.
One respondent recommended that radioisotopes be included in the MOEE's Priority
Pollutants List.
Response by ACES
1) Acceptable Risk Level:
The determination of an acceptable level of risk depends on a number of factors.
When setting environmental standards, regulatory agencies will often accept a risk of 1
excess cancer per million people exposed if the following circumstances are met:
-multiple media through which exposure can occur;
-a large affected population.
A risk of one excess cancer per one hundred thousand people exposed (i.e., 10 per
million) is often deemed acceptable if there is:
-a single medium of exposure;
-a limited affected population.
In the case of tritium, nuclear generating stations represent a point source for tritium
in drinking water. However, there is more than one medium of exposure (e.g., air,
food, etc.), and there is the potential for a large population to be impacted.
Therefore, an intermediate risk level of 5 excess cancers per miflion people exposed is
reasonable. MOEE currently has no formal policy on risk assessment which codifies
the standard setting process.
19
2) Health Effects Other Than Fatal Cancers:
The risk estimates carried out by the international radiological community identify
fatal cancers as the critical endpoint when setting an allowable dose. The WHO
expressly excludes health risks from non-fatal cancers and hereditary effects. ACES
considers that chronic environmental exposure to ionizing radiation presents health
risks over and above fatal cancers, including non-fatal cancers and multigenerational
effects.
The risk estimates for radionuclides served originally as a framework for occupational
standards for radiation protection for atomic workers. There are substantial
differences between occupational and environmental exposure to contaminants.
Occupational standards are generally established based, in part, on the following
assumptions:
-a healthy adult population;
-assuming a voluntary risk;
-individuals are exposed over a limited number of hours per day and a limited
number of years, not over their lifetime.
Factors such as exposure of sensitive populations, additive effects, other routes of
exposure, etc., are not taken into account in the risk estimates for radionuclides.
These factors raise issues of uncertainty in the risk calculations. ACES agrees that
these additional sources of uncertainty are areas of concern.
3) Uncertainty Factors:
The dose conversion factor used for tritium, its relative biological effectiveness and
the contribution to risk of organically bound tritium are all subjects of controversy
within the radiological community. For example, the RBE for tritium in the Rationale
Document is assumed to be one. A recent article in the radiation protection literature
concludes that the RBE is higher than one (Straume and Carsten 1993). Changes in
any of the above cited issues would likely result in a reduction of the allowable dose.
The "Petkau effect" refers to cell membrane damage caused by continuous, low level
exposure to beta emitters (Graeub 1992). This "effect" is based on the research
carried out by Dr. Abram Petkau on non-living membranes. His studies showed that
chronic exposure to low levels of tritium lowered the dose required to break the
membrane. The Committee considered that, although interesting, the Petkau effect
may not be relevant for human risk assessment because the studies were performed on
artificial phospholipid membranes, in vitro, which lack the repair mechanisms present
in living systems.
The combination of an intermediate acceptable risk level, uncertainties about other
potential health risks from chronic environmental exposures to radiation and additional
20
uncertainties in the parameters used in determining the risk estimate for tritium
provide impetus to lower the acceptable risk level from 5 excess cancers in one
million people exposed to one in one million. This risk level would result in an
ODWO of:
100 Bq/L (level reflecting lifelong exposure) -s- 5 =20 Bq/L
4) Historical Risk Assessment:
ACES agrees that the agencies responsible for risk assessment of radionuclides have
indicated that, in the past, they underestimated the risk these contaminants pose.
Consequently, the latest recommendations of the ICRP and the WHO have been
reduced by a factor of five to reflect the revised risk estimates.
5) Virtual Elimination:
ACES endorses the public's support of the principle of virtually eliminating persistent
toxic substances from the environment and of establishing a schedule for this reduction
over time. Tritium is persistent, with a half-life of 12.3 years, and is a human
carcinogen. ACES agrees with the DC position on the identification of radionuclides
with a half- life greater than six months as persistent toxic substances.
Recommendations
ACES recommends that a multimedia approach be used in establishing tritium
standards. Recognizing the existence of other potential pathways of exposure to
tritium in addition to drinking water, ACES further recommends that the Minister of
the Environment and Energy should undertake discussions with other jurisdictions to
implement this recommendation.
ACES further recommends that the MOEE establish a policy on risk estimation with
standard methodologies to evaluate risk and clear criteria for when deviations from
that methodology are required.
ACES recommends that radioisotopes that are toxic, persistent, and that have the
potential to bioaccumulate should be included in the Priority Pollutant List developed
by the MOEE.
Feasibility
Summary of Public Comment
The issue of cost analysis in applying the ODWO was raised by 6 respondents.
Comments centred on the need for demonstrated benefits in terms of pollution
reduction given the potential economic costs of a stringent tritium drinking water
21
objective. Respondents felt that this was not "beyond the scope" of the report, as
stated in the Rationale Document. The four respondents that supported an ODWO of
40,000 Bq/L all commented that the cost associated with a reduction of the standard
was a factor in their recommendations.
Five commenters addressed the lack of treatment technologies to remove tritium from
drinking water. They expressed concerns that due to the absence of treatment
technologies, the tritium level the consumer receives is the same level as in the raw
water. The respondents used this rationale to support a reduction in tritium emission
levels. Concerns about the lack of treatment technologies for tritium in drinking water
resulted in an additional 5 respondents discussing the location of water treatment
plants, with recommendations that they be situated in areas that can meet whatever
drinking water target level is set. One commenter recommended that Ontario adopt
the United States ban on building water supply plants within a five mile radius of
nuclear generating stations.
Response by ACES
ACES' s consultation was based on the MOEE's proposed ODWO of 7,000 Bq/L and
the feasibility thereof. The Rationale Document did not consider the feasibility of
lower levels. ACES has no comprehensive information on the feasibility of an
ODWO of less than or equal to 100 Bq/L. The information supplied by the MOEE's
Drinking Water Surveillance Program (DWSP) suggests that 100 Bq/L is rarely
exceeded and that 20 Bq/L is exceeded periodically near nuclear facilities1.
Background levels of tritium in the environment are declining due to the decay of
fallout over time. Currently, the most significant source of tritium in drinking water
that would result in a drinking water level in excess of 20 Bq/L is emissions from
nuclear facilities. No effective treatment technologies for the removal of tritium from
drinking water supplies exist. ACES agrees that the lack of an effective treatment
technology for tritium in drinking water is of concern and considers that this provides
additional support for reducing tritium emissions.
ACES believes that there is a need to investigate an ODWO of 20 Bq/L and below in
terms of technical feasibility and financial feasibility. Several years may be needed
for these feasibility studies, therefore ACES proposes a five year target for the
ODWO of 20 Bq/L and the policy options implied.
'Page 19 of the Rationale Document for the Development of an Interim Ontario
Drinking Water Objective for Tritium (MOEE 1993) states that "...the levels of tritium
in drinking water supplies in Ontario rarely exceed 100 Bq/L." Appendix E.l (page
25) of the same document lists the tritium results of the 1991 Drinking Water
Surveillance Program (DWSP). Of the 109 water supply plants surveyed, only the
Ajax Water Treatment Plant reported a tritium level over 100 Bq/L.
Appendix 7 lists the 1991 tritium data from the Nuclear Surveillance Program as
reported in Appendix E.2 of the MOEE Rationale Document.
22
Due to the lack of an effective means of removing tritium from drinking water, the
proximity of nuclear facilities should be borne in mind when approvals are sought for
the construction or expansion of water supply plants.
By summing the effects of all radionuclides and applying a committed effective dose to
the total, the radiation risk assessment paradigm implicitly weighs the benefits of the
nuclear industry at a much greater level than those of other industries (e.g., the
agrochemical industry for which each additional pesticide or herbicide is evaluated and
regulated independently). ACES challenges this weighting and questions the rationale
for attributing these extraordinary benefits to the nuclear industry while other
industrial sectors are treated less generously.
Recommendations
ACES recommends that the Ontario Drinking Water Objective for Tritium be set
immediately at 100 Bq/L. ACES further recommends that, due to the fact that
tritium is a human carcinogen and because of the many uncertainties in the risk
assessment, the tolerable level of tritium in drinking water be reduced to 20 Bq/L
in 5 years with the goal of further reduction as human contributions to tritium
background levels decline. The five year schedule for the reduction acknowledges
the need for technical and financial feasibility studies on the ODWO of 20 Bq/L.
In addition, ACES recommends that this standard be applied as a health-based
Maximum Acceptable Concentration, so that when this drinking water standard
is exceeded, an alternative water supply should be made available.
ACES recommends that the MOEE undertake a comparative cost analysis of different
methods to achieve the recommended ODWO of 100 Bq/L and the five year target of
20 Bq/L.
ACES further recommends that the MOEE ensure that the feasibility of additional
tritium emission control strategies be assessed.
Implementation
Summary of Public Comment
A number of respondents (12) raised the question of jurisdictional authority over
radionuclides. Many of those expressed confusion over the multiplicity and range of
water-borne tritium standards, and were unsure about which ones are "safe". This
range includes the current Atomic Energy Control Board's (AECB) derived emission
limit for the Pickering Nuclear Generating Station of 210,000 Bq/L1, the current
Canadian Drinking Water Guideline of 40,000 Bq/L, the proposed ODWO of 7,000
Bq/L and the U.S. Environmental Protection Agency (U.S. EPA) drinking water
standard of 740 Bq/L.
23
The inclusion of radionuclides as persistent toxins in the International Joint
Commission's most recent biennial report was mentioned by 50% of those who
commented on jurisdictional issues.
Four comments from respondents dealt with the monitoring of tritium and three
comments addressed the impact of transboundary sources of tritium in drinking water,
especially the Fermi II radioactive waste water releases by Detroit Edison to Lake Erie
in February and March, 1994. The comments expressed concern that there is no
reliable on line monitor for sampling and tracking tritium discharges into water.
Two respondents raised the issue of enforcement of the drinking water objectives.
These comments expressed frustration with ineffective 'guidelines' and recommended
that enforcement become "credible and rational".
An advisory level in addition to the standard was discussed by seven respondents, five
of which supported this concept. The advisory was suggested to provide an alert to
communities when tritium contamination exceeds background levels, so that people
can choose not to drink the tap water.
Response by ACES
The regulation of radionuclides is, indeed, complex. Various jurisdictions have
different responsibilities. The regulation of all "nuclear facilities" and their discharges
is the mandate of the federal government under the Atomic Energy Control Act.
Because nuclear facilities represent a point source for tritium in drinking water and
because there is no water treatment technique to remove tritium, the standard for
tritium in Ontario drinking water may have an impact on the emissions, and therefore
possibly the operations, of Ontario Hydro and AECL nuclear plants. ACES was
unable to establish whether or not additional controls on tritium releases from these
plants are possible, and based its recommendation primarily on the health
considerations of tritium exposure from drinking water.
1 The AECB derived emission limit is an allowable release standard to water from
nuclear facilities. Although these emissions will affect tritium levels in drinking
water, this is not a drinking water standard.
24
More than 90% of Canada's nuclear generating capacity resides in Ontario, under the
auspices of Ontario Hydro. Ontario Hydro is a Provincial Crown corporation
responsible for the production and delivery of electrical power. Ontario Hydro reports
to the Minister of the Environment and Energy.
Each province has jurisdiction over its own water supplies. Section 29.(1) of the
Ontario Water Resources Act states that "For the purposes of this Act, the Minister
has the supervision of all surface waters and ground waters in Ontario." (OWRA
1994) Section 75.-(l)(i) of this same Act states that "[The Lieutenant Governor in
Council may make regulations,] prescribing standards of quality for potable and other
water supplies, sewage and industrial waste supplies, sewage and industrial waste
effluents, receiving streams and water courses;". It is on these bases that the Province
has jurisdiction over the quality of drinking water supplies.
In a section of their submission entitled "Different Limits for Tritium in Drinking
Water" Ontario Hydro stated that "It should be noted that the AECB operating licenses
specify that the nuclear station must also comply with all applicable provincial and
local regulations. This implies that we must comply with the most restrictive
regulations in cases where there is overlap of jurisdiction. "
The most recent draft of the Ontario Drinking Water Objectives (MOEE, 1993) states
that "The objectives outlined in this document prescribe standards of quality for
drinking water supplies. In carrying out its responsibilities under section 53 OWRA
[Ontario Water Resources Act], the MOEE applies the ODWO's in approving the
establishment of any water works or the extension of or change in any existing water
works...". The Approvals Branch of the MOEE, through the granting of Certificates
of Approval, specifies monitoring requirements. Regional staff of the MOEE are
responsible for enforcing these monitoring requirements at all water supply systems.
The Medical Officer of Health, through the Health Protection and Promotion Act has
the authority to judge whether water is safe for human consumption. ODWOs may be
used for this purpose.
ACES supports the concept of easier public access to drinking water survey
information. In their submission, Atomic Energy of Canada Limited Research
(AECL) suggested that drinking water survey information be provided on a regular
basis to the public in communities which express significant concern about their water
quality. One means they suggested for providing this information was through the
regular publication in newspapers of the concentrations in drinking water of all health
related parameters in comparison to their respective limits.
Recommendations
ACES recommends that frequent monitoring and timely, regular and public reporting
of tritium levels in nuclear facilities' emissions and water treatment plant intakes in the
vicinity of nuclear facilities should be ensured by the MOEE.
25
ACES is unaware of any monitoring program currently in place that would detect
tritium pulses. Due to the concerns raised regarding potential risks to the fetus in
utero, ACES recommends that the MOEE ensure that the timely reporting of periodic
tritium pulses is pursued.
ACES strongly supports the principles of pollution prevention and the phase out of
persistent, toxic contaminants, like tritium. In keeping with these goals, ACES
recommends that discussions should be initiated with Ontario Hydro and AECL
regarding the feasibility of reducing tritium emission levels from nuclear facilities in
Ontario.
ACES recommends that the Ministry of Labour Radiological Drinking Water
Monitoring data should be made available to the public in an accessible and timely
manner and published along with the Drinking Water Surveillance Program data.
Need for
Additional
Studies
Summary of Public Comment
Five submissions dealt with the issue of the need for additional health studies. Four
commenters expressed concerns over the lack of information on long term, low level
radiation ingestion exposure effects.
Response by ACES
ACES agreed that there is a lack of information on the long term, low level ingestion
exposure effects of radiation and has concerns over the promised follow up health
studies by the AECB that have yet to be conducted. ACES considers such studies to
be required, but believes that the adverse health effects of ionizing radiation are
sufficiently well established that public monies would be more effectively spent in
controlling tritium releases to the environment rather than on further study of its health
effects.
Recommendations
ACES recommends that follow up studies on long term, low level exposures to
radiation be completed as recommended by previous AECB reports, but that these
studies not proceed immediately if the cost associated with them would delay the
implementation of the recommended standard.
ACES further recommends that representatives selected by the community be included
in the planning committee for future health studies to increase public confidence in the
study.
26
Other Comments
and
Recommendations
Summary of Public Comment
A number of other comments and recommendations were received during the
consultation. These included suggestions regarding the process (3 comments), i.e.,
requests for a "full" tritium review, criticisms and suggestions for improvement of the
structure and content of the Rationale Document (4 comments), and concerns
regarding the ecosystem effects of tritium contamination (2 comments).
Response by ACES
In general, ACES was pleased with the process and with the extent and quality of the
responses received to the request for comment. About 37% of those who requested
additional information actually commented. ACES felt this degree of response was
excellent given the scientific nature and complexity of the issues.
27
Summary of
Recommendations
ACES recommends that the Ontario Drinking Water Objective for Tritium be set
immediately at 100 Bq/L. ACES further recommends that, due to the fact that
tritium is a human carcinogen and because of the many uncertainties in the risk
assessment, the tolerable level of tritium in drinking water be reduced to 20 Bq/L
in 5 years with the goal of further reduction as human contributions to tritium
background levels decline. The five year schedule for the reduction acknowledges
the need for technical and financial feasibility studies on the ODWO of 20 Bq/L.
In addition, ACES recommends that this standard be applied as a health-based
Maximum Acceptable Concentration, so that when this drinking water standard
is exceeded an alternative water supply should be made available.
ACES recommends that a multimedia approach be used in establishing tritium
standards. Recognizing the existence of other potential pathways of exposure to
tritium in addition to drinking water, ACES further recommends that the Minister of
the Environment and Energy should undertake discussions with other jurisdictions to
implement this recommendation.
ACES further recommends that the MOEE establish a policy on risk estimation with
standard methodologies to evaluate risk and clear criteria for when deviations from
that methodology are required.
ACES recommends that radioisotopes that are toxic, persistent, and that have the
potential to bioaccumulate should be included in the Priority Pollutant List developed
by the MOEE.
ACES recommends that the MOEE undertake a comparative cost analysis of different
methods to achieve the recommended ODWO of 100 Bq/L and the five year target of
20 Bq/L.
ACES further recommends that the MOEE ensure that the feasibility of additional
tritium emission control strategies be assessed.
ACES recommends that frequent monitoring and timely, regular and public reporting
of tritium levels in nuclear facilities' emissions and water treatment plant intakes in the
vicinity of nuclear facilities should be ensured by the MOEE.
ACES is unaware of any monitoring program currently in place that would detect
tritium pulses. Due to the concerns raised regarding potential risks to the fetus in
utero, ACES recommends that the MOEE ensure that the timely reporting of periodic
tritium pulses is pursued.
28
ACES strongly supports the principles of pollution prevention and the phase out of
persistent, toxic contaminants, like tritium. In keeping with these goals, ACES
recommends that discussions should be initiated with Ontario Hydro and AECL
regarding the feasibility of reducing tritium emission levels from nuclear facilities in
Ontario.
ACES recommends that the Ministry of Labour Radiological Drinking Water
Monitoring data should be made available to the public in an accessible and timely
manner and published along with the Drinking Water Surveillance Program data.
ACES recommends that follow up studies on long term, low level exposures to
radiation be completed as recommended by previous AECB reports, but that these
studies not proceed immediately if the cost associated with them would delay the
implementation of the recommended standard.
ACES further recommends that representatives selected by the community be included
in the planning committee for future health studies to increase public confidence in the
study.
29
References
Advisory Committee on Environmental Standards (ACES). 1992. A Standard for N-
Nitrosodimethylamine (NDMA) A recommendation to the Minister of the
Environment. ACES Report 92-01.
Clarke, E.A., McLaughlin, J., and Anderson, T.W. 1989. Childhood leukaemia
around Canadian nuclear facilities - Phase I. AECB.
Clarke, E.A., McLaughlin, J., and Anderson, T.W. 1991. Childhood leukaemia
around Canadian nuclear facilities - Phase II . AECB.
Committee on the Biological Effects of Ionizing Radiation (BETR). 1990. Health
Effects of Exposure to Low Levels of Ionizing Radiation. BEIR V. National
Academy Press. Washington, D.C.
Graeub, R. 1992. The Petkau Effect: Nuclear Radiation, People and Trees. Four
Walls Eight Windows Press. New York, N.Y.
International Commission on Radiological Protection (ICRP). 1991. 1990
Recommendations of the International Commission on Radiological Protection. ICRP
Publication No. 60. Pergamon Press. Elmsford, N.Y.
International Joint Commission (IJC). 1994. Seventh Biennial Report on Great Lakes
Water Quality. International Joint Commission, Washington D.C. and Ottawa,
Ontario.
Johnson, K.C., and Rouleau, J. 1991. Tritium releases from the Pickering Nuclear
Generating Station and birth defects and infant mortality in nearby communities 1971-
1988. AECB Project No. 7.156.1
Ministry of the Environment and Energy (MOEE). 1993. Ontario Drinking Water
Objectives (Final Draft- 1993). Water Resources Branch.
Ministry of the Environment and Energy (MOEE). 1993. Rationale Document for
the Development of an Interim Ontario Drinking Water Objective for Tritium.
Standards Development Branch.
Ontario Hydro, Health and Safety Division. 1992. Annual Summary and Assessment
of Environmental Radiological Data for 1991. Ontario Report HSD-HP-92-9.
30
Ontario Water Resources Act. 1994. Queen's Printer for Ontario.
Straume, T., and Carsten, A.L. 1993. Tritium radiobiology and relative biological
effectiveness. Health Physics 65(6): 657-672.
World Heath Organization (WHO). 1993. Guidelines for Drinking Water Quality.
Second Edition. World Health Organization, Geneva.
31
Appendix 1: Background Material on Tritium
Ontario
Advisory Comité 40 St Clair Avenue West 40. avenuo St Clair ou«3t
Committee OP Consultatif Suite 401 Bureau 401
Environmental des normes Tof°"to ON M4V1M2 ibromoON M4V1M2
Standards environnementales
TRITIUM
January, 1994
The Honourable Bud Wildman, Minister of the Environment and Energy, has asked ACES to
conduct a public consultation and make recommendations on his Ministry's proposed Interim
Ontario Drinking Water Objective for Tritium of 7,000 Becquerels per litre (Bq/L).
The current Ontario Drinking Water Objective for radionuclides, including tritium, is 40,000
Bq/L.
ACES is an independent advisory body responsible for recommending to the Minister sound,
practical standards for environmental contaminants, as well as policies, principles and
procedures for setting environmental standards.
We are writing to ask for your comments on this proposed standard. If you are concerned
about the environment and would like to make a difference, we urge you to get involved in
this review.
ACES will be holding an information session in Ajax on January 27, 1994, at the Ajax
Recreation Centre, 75 Centennial Road, Ajax, at which we will explain our public
consultation process. We have invited Ministry of the Environment and Energy (MOEE)
staff to answer your questions about the development of the standard. If you cannot attend
this meeting and wish more information, a record of the session can be ordered. The
advertisement on the reverse provides important information regarding the consultation
program.
We would appreciate it if you would advise others who might have an interest in this issue of
this consultation.
The deadline for written comments is March 10, 1994.
Disponible en français sur demandé. (Please see over)
Important information enclosed regarding:
1) Consultation on the Proposed Soil, Drinking Water and Air Standards for Lead;
2) ACES's mailing list.
32
Setting a standard
for environmental
protection
WE WANT TO
HEAR FROM YOU
ABOUT TRITIUM
The Minister of the Environment & Energy has requested
that the Advisory Committee on Environmental Standards
(ACES) conduct a public consultation on the proposed new
Interim Ontario Drinking Water Objective of 7,000
Becquerels/Litre (Bq/L) for Tritium. The current Ontario
Drinking Water Objective is 40,000 Bq/L.
ACES was established to contribute to environmental
improvement by advising the Minister on standards for
environmental contaminants. We are seeking public input
before reporting to the Minister and would like to invite
you to take part in this public consultation.
ACES is particularly interested in your answers to the fol-
lowing questions, although we welcome any other com-
ments you may have:
1 . Is the proposed standard acceptable?
2. If noti what is the basis for finding the
proposed level unacceptable?
3. Do you have an alternative level to propose
and what is your rationale for suggesting
this level?
The deadline for written comments is March 10, 1994. If
you are concerned about the environment and would like
to make a difference then we urge you to get involved!
For further information, and copies of the documentation,
please contact:
Advisory Committee on Environmental Standards
40 St. Clair Ave. West, Suite 401
Toronto, Ontario M4V 1M2
Telephone: (416) 314-9265
Fax: (416) 314-9270
Ontario
33
Background Documents for Tritium
The following documents were used in the development of the proposed tritium
standard:
1. Health and Welfare Canada. 1993. Guidelines for Canadian Drinking Water
Quality-Fifth Edition. Canada Communications Group - Publishing. Ottawa,
Canada.
2. National Council on Radiation Protection and Measurements (NCRP). 1987.
Ionizing Radiation Exposure of the Population of the United States. NCRP Report
No. 93. National Council on Radiation Protection and Measurements. Bethesda,
Maryland.
3. Committee on the Biological Effects of Ionizing Radiation (BEIR). 1990. Health
Effects of Exposure to Low Levels of Ionizing Radiation. BEIR V. National
Academy Press. Washington, D.C.
4. International Commission on Radiological Protection (ICRP). 1991. 1990
Recommendations of the International Commission on Radiological Protection.
ICRP Publication 60. Pergamon Press. Elmsford, N.Y.
5. United Nations Scientific Committee on the Effects of Atomic Radiation
(UNSCEAR). 1988. Sources, Effects and Risks of Ionizing Radiation. United
Nations. New York, N.Y.
6. United Nations Scientific Committee on the Effects of Atomic Radiation
(UNSCEAR). 1986. Genetic and Somatic Effects of Ionizing Radiation. United
Nations. New York, N.Y.
7. United States Environmental Protection Agency. 1991. National Primary
Drinking Water Regulations: Radionuclides. Federal Register, V. 56, No. 138,
July 18, 1991. pp. 33050-33127.
8. World Health Organization. 1993. Guidelines for Drinking Water Quality .
Second Edition. World Health Organization, Geneva.*
These reports may be reviewed at the following locations:
Advisory Committee on Environmental Clerks Department
Standards Town of Ajax
Library 65 Harwood Avenue South
40 St Clair Ave. W Ajax, Ontario
Suite 401 LIS 2H8
Toronto, Ontario
M4V 1M2
For further information, please call the ACES office at (416) 314-9265.
*This document was not published until following the launch of the public consultation
on January 10, 1994. The draft version was used by the MOEE in the development of
the proposed ODWO. Copies were provided by ACES at the above listed locations with
the other documents for review. ~.
Ontario
Ministry
of the • • . ... -.>_
Environment
September 30, 1992
FOR FURTHER INFORMATION:
Elizabera Janz (416) 440-3479
Environmental Assessment Branch
Gerry Merchant (416) 323^333
- • Public Affairs and
'. - Communications Services Branch
NEW AJAX WATER SUPPLY PLANT TO PROCEED
- ON THE BASIS OF CLASS ENVIRONMENTAL ASSESSMENT
Environment Minister Ruth Grier today announced she has decided not to require an
individual environmental assessment of the proposed water supply plant in Ajax. The
decision is subject to a series of conditions drawn from the Environmental Assessment
Advisory Committee's (EAAQ report to the minister.
"I have taken steps to ensure that the community has the protection it needs without
unduly delaying completion of a much-improved and needed area water supply," Mrs. Grier
said. "I appreciate the concern area residents have about the potential effects of nuclear plant
discharges on their drinking water and I have considered their comments very carefully."
In her decision, the minister considered requests from the public that the project be
bumped-up to an individual environmental assessment. The major concerns expressed dealt
with the plant's location on the waterfront and with potential tritium levels in water from the
plant as a result of its proximity to the Pickering Nuclear Generating Station.
After the community's bump-up request was received by the Minister, she asked
EAAC to advise her on whether the project should be subject to a full environmental
assessment. The advisory committee recommended against the bump-up if a series of
1/2... 27592.NR ...•■■-
rwtntDO*
recyuh) wen
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conditions could be met by the region. They also advised that the province undertake a full
review of Ontario's standards for tritium.
Mrs. Grier decided to address public concerns about tritium by referring Ontario's
standards for tritium to the Advisory Committee on Environmental Standards (ACES) for
public review. The development of the water plant will be allowed to proceed while this
review is under way.
In addition, Mrs, Grier said staff of the ministry's Environmental Assessment Branch
will be consulting Ontario Hydro, the Atomic Energy Board and the ministries of health,
environment and energy on a recommendation by EAAC to establish a Durham Nuclear
Health Committee.
Mrs. Grier agreed with EAAC that the Regional Municipality of Durham's planning
process was adequate and that most of the. environmental concerns can be addressed through
appropriate terms and conditions. She set 21 conditions to which the region must agree
before construction on the new plant can proceed.
-30
2/2... 27592.NR
36
Ministry of Environment and Energy
Backgrounder on a recommended Interim
Ontario Drinking Water Objective for Tritium
The Ministry of Environment and Energy is recom-
mending that the current Ontario Drinking Water
Objective (ODWO) for tritium of 40,000 becquerels
per litre (Bq/L) be replaced by an interim Drinking
Water Objective of 7,000 Bq/L (a becquerel is a unit
used to measure radioactivity). This recommenda-
tion is based on a reassessment of the adverse
human health effects resulting from exposure to
radiation.
Background:
ODWOs are the primary tool used by the ministry to
ensure the acceptability of public water supplies.
Achieving drinking water objectives ensures aes-
thetically pleasing water that does not represent any
significant risk to the health of the consumer.
The need to re-examine the basis of the ODWO
for tritium resulted from a recommendation of the
Environmental Assessment Advisory Committee
(EAAC) concerning the new Pickering/Ajax water
treatment plant proposed by the Region of Durham.
EAAC advised that an individual environmental
assessment for the plant was not necessary provided
that certain concerns were addressed. One of these
concerns centred on the levels of radioactive sub-
stances, specifically tritium, in drinking water.
To address this concern, EAAC recommended
that the Minister ask the Advisory Committee for
Environmental Standards (ACES) to carry out a
public review and advise on an appropriate standard
for levels of tritium in drinking water. In order to
conduct this review, the ministry has prepared this
backgrounder as a general introduction to the
Rationale Document for the Development of an
Interim Ontario Drinking Water Objective for
Tritium.
Properties of tritium:
Tritium is a naturally occurring, radioactive form of
hydrogen. As part of its natural decay, tritium emits
radiation which is relatively weak, compared to that
emitted from other radioactive substances. Neverthe-
less, all radiation released by radioactive substances
is considered carcinogenic in humans; the risk of
developing cancer is considered to be proportional to
the radiation dose received.
The most common form of tritium is tritiated
water, which is a by-product of water-cooled nuclear
generating stations and is indistinguishable in terms
of taste, smell and texture from normal water.
Human exposureto tritium results primarily from
ingestion or inhalation; once taken in, tritium is
distributed rapidly throughout the body.
The basis for the revised objective:
The revised ODWO for tritium is based upon the
recommendation of the World Health Organization
that the annual "dose" received from drinking two
litres of water a day be set at 0.1 mSv (1000 mSv = 1
sievert; a sievert is the unit used to measure a radio-
active "dose"). The recommended "dose" represents
an estimated risk of five cases of cancer for every
million people exposed; however, that figure is less
than five per cent of the "dose" attributable to
background radiation. The revised ODWO of 7,000
Bq/L for tritium is derived by converting sieverts
into becquerels using an appropriate conversion
-factor for tritium.
-¥f-
fSà r\
4-,-s ^ ^
Sources of exposure to radiation:
Natural sources of radiation, such as cosmic rays
and naturally occurring radioactive substances,
account for more than 80 per cent of an individual's
exposure to radiation. Other sources, such as medi-
cal X-rays, account for approximately 11 to 15 per
cent of annual exposure. Exposure to tritium in
drinking water generally accounts for less than 0.1
per cent of overall annual exposure.
In Ontario, tritium in drinking water is moni-
tored under the Ontario Drinking Water Surveil-
lance Program as well as under specific surveillance
programs carried out in the vicinity of nuclear
generating stations. Data obtained from these
programs indicate that the level of tritium in drink-
ing water in Ontario is generally very low and
rarely exceeds 100 Bq/L. The maximum value
recorded in 1991 was 370 Bq/L in Petawawa.
Application of the 0DW0 for tritium:
The revised drinking water objective for tritium
applies when other radioactive substances are not
present in the water. In those cases where more
than one radioactive substance is present in drink-
ing water supplies, the maximum allowable limit for
all radioactive substances is set so that the "dose"
derived from all radioactive substances in the
drinking water does not exceed 0.1 mSv.
In the case of emergency situations, such as the
spill or release of nuclear material, the Nuclear
Emergency Plan administered by the Ministry of
Solicitor General applies. In such situations, advice
is sought from various ministries on a case-by -case
basis as to an appropriate course of action. For
decisions affecting the acceptability of drinking
water supplies, the objectives for all radioactive
substances, including tritium, would be among the
factors considered when arriving at an appropriate
decision.
The interim ODWO for tritium will be applied
as a health-related maximum acceptable concentra-
tion and will be reviewed once the Canadian Drink-
ing Water Guidelines for radioactive substances are
revised.
For further information:
To obtain the Rationale Document for the
Development of an Interim Drinking Water Objective
for Tritium or other information related to the
proposed review, please contact:
Advisory Committee on
Environmental Standards
40 St. Clair Ave. W.
Toronto, Ont.
M4V1M2
Tel: (416) 314-9265
48-
Appendix 2: List of Respondents in ACES' s Public Consultation on
Tritium
Members
A. Anderson
M.E. Anderson
M. Bednarz
R. Bell
B. Biederman
C.B. Bigham
J. Brackett/&
I. Kock
K. Brosemer
P. Brown
W.F.M. Brown
E. Burt
G. Colm
W. Cooney
H. Cross
R. Cuyler
A.G. Darnley
E. deQuehen
C. Duschenes
M.J. Diamond
R. Doomernik
Ajax Citizens for the Environment, Ajax, Ontario
Director of Public Health Inspection, York Region, Newmarket,
Ontario
President, The Beaver Valley Heritage Society, Clarksburg, Ontario
C. Bruce Bigham Consulting, Deep River, Ontario
Durham Nuclear Awareness, Oshawa, Ontario
Clean North, Sault Ste. Marie
Councillor, Ward 5, Town of Ajax, Ajax, Ontario
Walter Brown Associates, Mississauga, Ontario
International Geochemical Mapping, Ottawa, Ontario
Northumberland Environmental Protection, Northumberland, Ontario
Technical Director, Fasson Canada Inc., Ajax, Ontario
39
F. Eggert &
S. Eggert
V.E. Emerson
V.E. Emerson
H. Emery
I. FairLie
B. Fergusson
M. Fisher
J. Foster
R. Frank
J.C. Fraser
Pickering beach Residents' Association, Ajax, Ontario
President, The Brereton Field Naturalists' Club
The Entry Group, Toronto, Ontario
Town Engineer, Town of Dryden, Dryden, Ontario
Durham Wetlands and Watersheds, Oshawa, Ontario
Chairperson of the Conservation Committee of the Guelph Field
Naturalists, Guelph, Ontario
Manager, Water Quality, Windsor Utilities Commission, Windsor,
Ontario
D. Golden-Rosenberg
R.D. Graham Manager, AECL Research, Chalk River, Ontario
H. Guttman Chair, American Water Works Association, Toronto, Ontario
K. Hansenberger
P. Hartwig
O. Hendrickson
H. Henrikson
D. Hiner
P. Hutton
J. Jackson
I. Judah
M.J. Kern
Community Liaison Group, Deep River, Ontario
Concerned Citizens of Renfrew County, Ottawa, Ontario
President, The Little Cataraqui Environment Association, Kingston,
Ontario
Atikokan Citizens for Nuclear Responsibility, Mattawa, Ontario
Conserver Society of Hamilton and District Inc. Hamilton, Ontario
Citizens' Network on Waste Management, Kitchener, Ontario
Enviro-Hai-Tech, Montreal, Québec
40
Z. Kleinau
I. Kock
S. Leonhardt
N.C. Lind
A. Lovett
C.W. Lundy
P. Lush
H. MacDonald
R. Maclntyre
A. Macpherson
R. Maruska
P. Maslak
J. McEwan
K.G. McNeill
C. Mobbs
D.K. Myers
P.C. Nanda
K.E. Nash
J.S. Nathwani
B. NeU
O. Nigol
N. Parrott
Bruce Peninsula Environment Group, Lions' s Head, Ontario
Durham Nuclear Awareness, Oshawa, Ontario
Pickering Ajax Citizen's Together For The Environment, Pickering,
Ontario
Professor Emeritus, University of Waterloo, Victoria, B.C.
Regional Clerk, The Regional Municipality of Durham, Whitby,
Ontario
Sault Area Nuclear Awareness, Goulais River, Ontario
Ontario Hydro, Toronto, Ontario
N.C.M.W.M., Grimsby, Ontario
Professor Emeritus of Physics, University of Toronto, Toronto, Ontario
Consumers' Association of Canada (Windsor), Kingsville, Ontario
Director, Nuclear Waste and Environment Services, Ontario Hydro
Nuclear, Toronto, Ontario
Joint Committee on Health and Safety, The Royal Society of Canada,
The Academy of Engineering, Toronto, Ontario
41
T.E. Parry
C. Peabody
B. Pellier
R. Robinson
N. Rubin
C. Sauriol
J. Scott
L. Segatti
L.R. Silver
H.B. Stevens
I.J. Stuart-Sheppard
J.E. Taylor
B.J. Vandenhazel
R. Waterston
B. Willard
S. Willard
R.S. Wilson
P.R. Youakim
J. Young
Director of Engineering, Town of Whitchurch-Stouffville, Stouffville,
Ontario
Chair, Social Action Committee, Unitarian Congregation of South Peel,
Mississauga, Ontario
Ridgetown Public Utilities Commission, Ridgetown, Ontario
Energy Probe Research Foundation, Toronto, Ontario
Director, Elgin St. Thomas Health Unit, St. Thomas, Ontario
Manager, Albright & Wilson Americas, Dunnville, Ontario
Ajax Save the Waterfront Committee, Ajax, Ontario
Black Hackle Engineering, Toronto, Ontario
Technologist, Environment Canada, Burlington, Ontario
42
Appendix 3: Summary Tables of Public Comments
Please Note: ACES has endeavoured to present comment summaries that are a true
reflection of the content and context of the responses received. Paraphrased comments
are indicated by their inclusion in square brackets ([ ]). Complete written
submissions are available for public review at the ACES office. The names of
respondents not representing an organization have been removed in accordance with
the Freedom of Information and Protection of Privacy Act requirements.
43
Comments Regarding the Proposed Level
Support no change from 40,000 Bq/L
Name
C. Bruce Bigham
Consulting
Deep River, Ont.
The Entry Group
Toronto, Ont.
Town of Dryden
Dry den, Ont.
Ridgetown Public
Utilities Commission
Ridgetown, Ont.
Comment
To answer the questions in your ad I offer the following:
1. No
2. See above [description of exposures from air travel, living
in the mountains etc., also the "Perhaps we are adapted to
higher levels and actually now suffer from a radiation
deficiency."]
3. The current level (40,000) or higher depending on an
economic analysis.
Leave it at 40,000 Bq/L if changing the standard will cost the
people of Ontario one red cent in added measuring
equipment, time required to create reports or creation of
committees or advertising expenses or BUREAUCRACY.
I would like to suggest that the present limits are low enough
and dropping them represents over-kill and as such a cost to
the country and to the environment. ...the present standard is
amply safe and no reduction is warranted.
In a day of increasing burdens, priority in the use of the
dollar must be of upmost importance... I would request that
no change be made to the current regulations at this time.
44
Support proposed level
Name
Comment
Individual
The proposed standards do not appear to have a negative
impact [socio-economically]. There appears to be no
contraindication to the reduction from 40,000 Bq/L to 7,000
Bq/L in drinking water.
Fasson Canada Inc.
Ajax, Ont.
No issue with the proposals sent-support both.
The Brereton Field
Naturalists' Club
Barrie, Ont.
...agree with the proposed reduction of allowable parts per
unit. We would urge the Ontario government to revise the
standards.
AECL Research
Chalk River Laboratories
Chalk River, Ont.
...the proposed Interim [ODWO] for tritium of 7000 Bq/L to
be generally within the range of what would be an acceptable
standard, provided it is applied in the intended manner: that
is as an upper limit of acceptability for lifelong
consumption.... AECL Research would strongly encourage
ACES to recommend that Ontario adopt the revised CDWG
standards once they are issued.
The Little Cataraqui
Environment Association
Kingston, Ont.
We strongly support the proposed reduction from 40,000
Bq/L.... even at 7,000 Bq/L... the risk of cancer increases by
5 cases per million, which we believe should be the
maximum acceptable...
Atikokan Citizens for
Nuclear Responsibility
Mattawa, Ont.
The Ministry is to be commended for their suggestion the
interim objective be lowered. It's a step in the right
direction.
Conserver Society of
Hamilton and District
Inc.
Hamilton, Ont.
I feel from reading the brief information that even the new
standard really isn't that useful in the general context, but
would be an acceptable overall standard.
Individual
I agree that the proposed criterion of 7000 Bq/L has been
determined using conservative reasoning and available
science.
Fisons Instruments Inc.
Ottawa, Ont.
These levels are acceptable
Durham Region
Whitby, Ont.
. . .the Health and Social Services Committee of Regional
Council considered the [ODWO for tritium] and ...adopted
the following recommendations of Committee: that the
proposed interim Ontario Drinking Water Objective for
tritium be endorsed;...
45
Ontario Hydro
Toronto, Ont.
Ontario Hydro is prepared to accept the recommendations of
the international scientific community. We believe that at
7,000 Bq/L, the Drinking Water Objective provides a good
measure of protection and can be applied practically as
recommended by the World Health Organization.
Ontario Hydro Nuclear
Toronto, Ont.
...Ontario Hydro supports the proposed interim level of 7,000
Bq/L for the drinking water objective for tritium.
Individual
I wish to record my support of a value of 7000 Bq/L for the
interim ODWO for tritium.
Individual
The proposed [standard] is acceptable if it reduces the level
of contamination to the lowest level possible.
Albright and Wilson
Americas
Dunnville, Ont.
We agree with these new maximum proposed standards. We
would also like to commend the process being used to bring
about the changes.
Black Hackle Engineering
Toronto, Ont.
This letter is to confirm support for the proposed
changes... The 7000 Bq/L (or lower) limit should be adopted
not from a health perspective, but from a safety perspective
to ensure that tritium sources are properly controlled.
Environment Canada
Burlington, Ont.
The proposed standards are acceptable. However, I would
like to suggest a reduction in levels with 2 sets of values in
mind and 2 target dates say in 1995 and the year 2002.
46
US level
Name
Comment
Windsor Utilities
Commission
Windsor, Ont.
...would encourage the ODWO be further reduced and
conform with the U.S. EPA proposed tritium limit in dw of
800 Bq/L.
Bruce Peninsula
Environment Group
Lion's Head, Ont.
We strongly feel that even the 7000 Bq/L limit is
unacceptable and that this limit should be brought down to at
least the U.S. EPA reading.
Consumers' Association
of Canada (Windsor)
Kingsville, Ont.
Since the lake waters are used by nuclear plants in USA and
Canada, it would be advisable for both countries to consider
harmonization of standards. It may be relevant to note that
current USA standards are set at much lower levels than the
proposed ACES standards.
Individual
...there is no economic reason for setting a tritium limit
...any higher than approximately 500 Bq\L. In order to have
consistency with U.S., I would like to suggest that a limit of
800 Bq\L be adopted at this time.
Individual
...adhere to dw stds that are as stringent as those in the
United States or better.
Individual
...my body is not more resilient to tritium than our
neighbours to the south. Their level is a far cry from our
existing Ontario level of 40,000 Bq/L. Additionally,
Americans restrict construction within five miles of a nuclear
plant, let alone building a water treatment plant.
Individual
A further lowering of the level to at least the U.S. level
currently proposed i.e. 2300 per litre.
47
Standard should be set at background level
Name
Comment
Durham Nuclear
Awareness
Oshawa, Ont.
...an appropriate drinking water standard for tritium should
be set at current background levels... bet ween 5 and 10 Bq/L,
and falling, so drinking water standards should tighten over
time to reflect the decay of tritium from weapons testing.
Clean North
Sault Ste. Marie, Ont.
[The standard should be set at less than 10 Bq/L, depending
on location].
Individual
Drinking water from WSP located less than ten kilometres
from a NGS shall provide drinking water with a maximum
tritium level of 8.7 Bq/L. For all other WSPs the maximum
amount allowed shall not exceed 300 Bq/L.
Durham Wetlands and
Watersheds
Oshawa, Ont.
...we want a Permanent Ontario Drinking Water Objective of
10 Bq/L and anything more is unacceptable...
Pickering Ajax Citizen's
Together for the
Environment
Pickering, Ont.
The interim level for tritium should be set at 5 to 10 Bq/L
until all information is gathered.
Individual
Commitment to zero tolerance of any levels of tritium above
background levels must be a priority... In addition, for any
level of tritium above background levels, I feel the public
should be advised.
Ajax Save the Waterfront
Committee
Ajax, Ont.
...we recommend that the std set by the MOEE should be 8.7
Bq/L, which is reasonable and doable.
48
Zero discharge
Name
Comment
Individual
Any levels of tritium are totally unacceptable to me. Pure
water is basic to good health.
Individual
Tritium should not be allowed in our drinking water.
Individual
As with the regulation of most other hazardous materials,
tritium should be subjected to ZERO DISCHARGE
objectives.
Individual
The proposed standard is not acceptable, it is too high.
Preferably it should be zero.
Individual
If one molecule of a substance can destroy or change forever
one cell then we recommend that a "zero" tolerance level be
permitted and that a "zero" input standard be put in place.
Individual
I believe it is obvious that no toxic substance ought to be
permitted to accumulate in our environment. There is no
suitable alternative.
Conservation Committee
Guelph Field Naturalists
Guelph, Ont.
It is our understanding that the two Federal Governments
around the Great Lakes are committed to zero discharge; why
is this not the case?
Individual
...recommend zero tolerance of toxic materials in drinking
water. . . [discussion of LFC virtual elimination
recommendations]
Citizens' Network on
Waste Management
Kitchener, Ont.
In its Seventh Biennial Report on Great Lakes Water Quality,
the IJC recommends that the "Governments incorporate those
radionuclides which meet the definition of persistent toxic
substances in their strategy for virtual elimination." We ask
the province to therefore immediately begin to develop a
strategy for eliminating the presence of tritium in water as a
result of human activities.
Individual
No level above zero discharge is acceptable... Production and
release of tritium at any level should be eliminated.
Sault Area Nuclear
Awareness
Goulais River, Ont.
...drinking water standards should reflect an attitude of zero
tolerance of all toxic materials.
Individual
I understand any contamination from a nuclear plant is only
acceptable at the level of NIL.
Individual
If it was not there in before then keep it out period... not try
to tell people x% is OK when you don't know.
49
Individual
It is our considered opinion that the only "safe" level of
tritium in drinking water is zero...
Consumers' Association
of Canada (Windsor)
Kingsville, Ont.
The Consumer Association of Canada commends the step
towards the number of becquerels from 70,000 to 7,000 but
would recommend ACES that it set further lower limits
towards a zero tolerance.
Social Action Committee
Unitarian Congregation
of South Peel
Mississauga, Ont.
...it is our contention that NO tritium should be allowed in
our drinking water. Only ZERO tritium is acceptable.
Individual
...this committee owes it to my family and the other families
in Ajax and Pickering to recommend a zero level of tritium.
Individual
My ideal standard for radiation in my drinking water is 0
Bq/L.
Individual
Economic considerations should not override ecological
concerns... I therefore recommend that the Ajax water plant
either will not proceed or be prevented from releasing
tritium.
Individual
We propose a level of 0 Bq/L... the objective that you
recommend to the MOEE should be 0 Bq/L, to honour your
mandate to provide a reference level based only on health
considerations.
Ajax Save the Waterfront
Committee
Ajax, Ont.
...the Ontario Drinking Water Objective for tritium in
drinking water should be 0 Becquerels/Litre. This
"objective" reflects what is desirable, based solely on health
considerations, and is a "reference level". That is the
objective we urge you to recommend to the MOEE, in
accordance with your mandate, [go on to recommend a
"standard" of 8.7 Bq/L]
Individual
...I must insist that the only "sound, practical standard" for
radionuclides in water is zero. How long will the nuclear
industry be given to meet the new objective of 0 Bq/L?
50
Recommended level other than proposed, US, background or zero.
Name
Comment
Individual
Drinking water from WSPs located less than ten km from a
NGS shall provide drinking water with a max. level of 8.7
Bq/L, for all other WSPs the max. allowed shall not exceed
300 Bq/L. Rationale is as follows: in the vicinity of a NGS
the max. acceptable level shall not exceed background level
found in Lake Ont. Elsewhere the allowable limit shall not
exceed 300 Bq/L which is a reasonable standard to live with.
Individual
It is my considered opinion that a reduction in the permissible
limits of tritium (and any other radioactive material) in
drinking water should be made as low as is possible
(unmeasurable?).
Concerned Citizens of
Renfrew County
Ottawa, Ont.
The goal should be zero discharge for cmpds such as tritium
that are known carcinogens. Recognizing that it will take
time to achieve this goal, we recommend that interim stds
.achieve at least a 100 fold reduction in the max. allowable
tritium concentration in dw, i.e., from the current 40,000 to
less than 400 Bq/L.
Energy Probe Research
Foundation
Toronto, Ont.
...set the ODWO...at a level in the range of 10 to 30 Bq/L,
if not lower.
Individual
I suggest that the "As Low as Reasonably Achievable"
requirement also be added to the new standard.
Individual
...if the objective was set at 100 Bq/L then on the rare
occasions when it's exceeded enforcement should result in the
necessary steps being taken to correct the problem at the
sources.
Town of Whitchurch-
Stouffville
Stouffville, Ont.
...allowable limits should be set much lower to ensure health
protection... only naturally occurring tritium need be
considered in the 100 Bq/L range.
51
Exposure
Basis of cancer risk calculation by WHO, ICRP etc.
Name
Comment
Individual
Applying the most recent dose to risk relationships published
by the ICRP... the additional risk of serious radiation induced
disease will be around 5 per million per year or about 1 in
3000 per lifetime. Risks of this magnitude ...are
acceptable...
Energy Probe Research
Foundation
Toronto, Ont.
...several references [in the transcripts] to cancer risks to
people "exposed over a lifetime" should refer to fatal cancer
risks over a lifetime from exposure over only a single year.
52
2 litre drinking water consumption level
Name
Comment
American Water Works
Association
Toronto, Ont.
The Interim Objective calculation uses an annual consumption
factor assuming 2 L/day. Almost all other objectives in the
ODWO are based on a 70 kg person consuming 1.5 litres of
water per day over 70 years. The document should outline
the justification for varying from the norm when setting
drinking water objectives.
Bruce Peninsula
Environment Group
Lion's Head, Ont.
We feel that the 2 1 consumption factor is too conservative as
DW is consumed as ingredient in cooking, baking, steaming,
soft drinks, beer and other beverages.
53
Risk
Historical risk assessment by international agencies
Name
Comment
Durham Nuclear
Awareness
Oshawa, Ont.
The MOEE rationale document on tritium standards in dw
adopts, without question, the position of international
agencies which have historically underestimated the risks of
radiation exposure.
Individual
The rationale document relies entirely on information
generated by both the EPA and the WHO. The latter uses
data based on studies of survivors of the atomic blasts in
Hiroshima and Nagasaki . Interestingly , ... the maximum
allowable dose has been reduced from 0.5 mSv down to 0.1
mSv. Does this mean in another 13 years it will again be
reduced?
Individual
Outline in their comments suspicion of any groups ability to
assess the impact of tritium in drinking water due to historical
view of radiation exposure, i.e., X-rays in the 1930s; atomic
bomb tests in the 1940s etc.
Individual
Since for many decades, scientists have been underestimating
the risks associated with radiation exposure and our
understanding of radioactive substances is not yet complete,
how can we be sure what exactly an appropriate margin of
safety is when calculating life time exposures?
Energy Probe Research
Foundation
Toronto, Ont.
The official sources of the risk coefficients for radiation
carcinogenesis the underlie the proposed
ODWO... have... consistently underestimated the actual
effectiveness of radiation at causing cancer. There is no
scientific or political reason to assume this has ended. . .What
is clear is that believing yesterday's... was not adequately
prudent.
Individual
Are we supposed to be reassured by the fact that these groups
of experts all were wrong by a factor of 5 between 1980 and
1993? What reassurances do we have that they are now
right?
54
Acceptability of cancer risk
Name
Comment
Ontario Section
American Water Works
Association
Toronto, Ont.
The rationale document cites the calculated cancer risk as 5
fatal cancers per 1 million people exposed. A conservative
public health approach is to use a cancer risk level of 1 in 1
million over a 70 year lifetime.
Citizens' Network on
Waste Management
Kitchener, Ont.
Additional cancer risk of five in one million is an
unacceptably high additional cancer risk. For example, the
City of Toronto has set one in a million as the highest
acceptable additional cancer risk.
Energy Probe Research
Foundation
Toronto, Ont.
...we know of no reason to believe that... an additional five-
per-million risk of fatal cancer [is] an acceptable risk from
one single contaminant in one year's drinking water. A
lifetime of that exposure would present a 300 per million total
additional risk of fatal cancer, and approx. a 750 per million
total additional risk of non-fatal cancer.
55
Additional Sources of Uncertainty
Sensitive Populations
Name
Comment
Clean North
Sault Ste. Marie, Ont.
[Susceptible populations need to be considered in risk
assessment. Developmental effects are an issue.]
Individual
We request that in setting stds the Committee adopt a std
which takes into consideration the effect on a developing
fetus.
Individual
Medical research seems to have found that small children
living down wind from a "Station" show a far greater risk of
attracting LEUKAEMIA.
Citizens' Network on
Waste Management
Kitchener, Ont.
We find it disturbing to compare sources of radiation and say
that tritium intake as a result of drinking water generally
accounts for less than 0.1 % of overall exposure. It isn't
general exposure that matters most. Standards must be set
for those people who are subject to the highest exposures and
receive the higher than average intake because of drinking
water.
Bruce Peninsula
Environment Group
Lion's Head, Ont.
Risk assessment does not take into account that children have
a much smaller ratio of body weight to water and food
intake. They also have a much higher rate of metabolism.
Children would be at a much higher than the 5 fatal cancers
per million population. They would also have a longer
exposure time than adults... radiation accumulates in the body
over a lifetime.
Individual
I am particularly interested in potential impacts as they relate
to children, and women-particularly women in their child
bearing years.
Individual
Ingestion rates and dose conversion factors for infants and
children are age-dependent, therefore the dose to tritium in
dw relationship may be different to that of adults. I believe
this should be addressed.
Individual
. . . [although this may appear to be a safe level for an
adult]... due to the physiological changes occurring within a
growing child, that may not be an appropriate exposure and
thus would be exposing children to a greater risk than
assumed. Also, no listed comparison was made with regard
to a fetus or a pregnant woman...
56
Energy Probe Research
Foundation
Toronto, Ont.
[Concerns raised over exposure in pregnant women and the
effects to the ova of her female fetus... i.e., the fetus' ova
incorporate tritiated hydrogen which then decays over the
next 12 to 25 years, damaging the surrounding genetic
material and resulting in birth defects in her offspring]
Individual
It has been well established that young children, foetuses, and
even the "stem cells"... are more vulnerable to various toxins
than are healthy adults, because their cells are dividing much
more rapidly.
Individual
We understand that the risk assessments for the proposed stds
are based on "kilogram per body weight". Which body
weight have you used? Is it the 155 lb. male?
Individual
The myth is that "One standard fits all". The reality is that
"Standards for adults may be 100 to 1000 times too high for
fetuses" .
57
Concerns re: long term low level radiation exposure
Name
Comment
Ajax Citizens for the
Environment
Ajax, Ont.
We believe there should be testing done on the long term,
low level, cumulative effects of tritium in drinking water, and
new acceptable levels determined.
Individual
[The ODWO is based on] a radiation dose external to the
body. The effects of long term low level tritium ingested in
the dw, although not known at this time, are in all likelihood
much more severe than that due to external radiation.
Individual
We are still not sure of the long term effects of low level
radiation.
Individual
...how can the long term health effects from a life of
drinking slightly tritiated water be deduced from studies of A-
bomb victims?
58
Advisory level
Name
Comment
Individual
We urge that nothing above background levels be tolerated
without a public advisory being given.
AECL Research
Chalk River Laboratories
Chalk River, Ont.
[An advisory level] appears to be contrary to the stated
purpose and application of ODWO's and CDWG's... There
appears to be no real reason to single out tritium in the
province-wide ODWO's for special treatment which is not
given to other health-related parameters. One alternative
...might be for municipal authorities in communities which
express significant concern about water quality to routinely
issue data directly to the public (e.g. though newspapers) on
concentrations in [dw] of all health related parameters,
including tritium, in comparison to their respective limits.
Any such special provisions should be established as needed,
and should not be established as Province-wide requirements
in the ODWO's.
Durham Nuclear
Awareness
Oshawa, Ont.
...two action levels should be set for tritium in drinking
water. The first action level should be set near normal
background levels, and if that level is exceeded, a public
advisory should be provided to allow people to make the
choice of not drinking tap water. A second action level
should be set which would trigger the shutdown of the water
supply plant and a temporary shift to alternative water
sources.
Individual
Commitment to zero tolerance of any levels of tritium above
background levels must be a priority... In addition, for any
level of tritium above background levels, I feel the public
should be advised.
Sault Area Nuclear
Awareness
Goulais River, Ont.
The proposed standard of 7,000 Bq/L is too high, considering
that the present background levels of tritium in the Great
Lakes are less than 10 Bq/L. Any alternative levels beyond
background levels should not be accepted without a full
public advisory being given.
Individual
...I shudder to think of the spills we do not hear about,
[could be interpreted as rec. for spills advisory?]
Ontario Hydro Nuclear
Toronto, Ont.
We also support the method of application of the [dw]
objective recommended by the [WHO]... and [MOEE]...a
single action level where the situation is to be investigated
and further possible action considered when concentrations
reach 100% of the objective.
59
Sunsetting
Name
Comment
Durham Nuclear
Awareness
Oshawa, Ont.
...an appropriate drinking water standard for tritium should
be set at current background levels... between 5 and 10 Bq/L,
and falling, so drinking water standards should tighten over
time to reflect the decay of tritium from weapons testing.
Individual
. . .phaseout and cut off deadlines and timetables reflecting the
current serious situation of tritium and other radionuclide
emissions.
Citizens' Network on
Waste Management
Kitchener, Ont.
In its Seventh Biennial Report on Great Lakes Water Quality,
the IJC recommends that the "Governments incorporate those
radionuclides which meet the defmition of persistent toxic
substances in their strategy for virtual elimination. " We ask
the province to therefore immediately begin to develop a
strategy for eliminating the presence of tritium in water as a
result of human activities. This strategy should include
.precise time lines.
Individual
What is needed is a phase out of polluting industries, clean
up and rehabilitation programs, with an objective of
eliminating man made contaminants from our
environment... [the standard] should be reviewed yearly to
reduce it even further.
Environment Canada
Burlington, Ont.
I would like to suggest a reduction in levels with 2 sets of
values in mind and 2 target dates say in 1995 and the year
2002.
60
Synergistic or additive effects
Name
Comment
Individual
Mixed with other chemicals, taken up by foliage, soil, plants
and animals it becomes part of our food chain.
Individual
...the combined affect of all pollutants in our drinking water
remains to be unknown. In my opinion the focus should be:
... 3. Combined effects of all pollutants.
The Little Cataraqui
Environment Association
Kingston, Ont.
...cancer incidence increases by 5 cases per million, which
we believe should be at least the maximum acceptable,
bearing in mind that this is just one of many chemicals that
increase cancer rates.
Citizen's Network on
Waste Management
Kitchener, Ont.
The use of risk numbers to justify accepting a contaminant in
water does not take into account the cumulative impact of the
various sources of contaminants in our
environment... [example given hypothesizing number of
chemicals in evn. 110,000 and number that cause cancer
5,500;] If each of those chemicals contributes a 1 in 100,000
risk, that's a final risk of 1 in 20,000. According to present
day de minimus standards, that's neither negligible nor
acceptable.
Bruce Peninsula
Environment Group
Lion's Head, Ontario
Risk assessments target only the effects of one specific toxic
chemical on human health but there is growing evidence that
chemicals are entering into combinations with other
substances with unknown effects on humans.
Individual
[reasons for finding std unacceptable]... how these unknowns
will react with other chemicals already present or yet to be
developed.
Individual
Issues which I feel must be addressed include: ...the
synergistic effects of tritium and (other radioactive water)
released by PNGS combined with Ontario Hydro's tritium
removal facility at the DNGS and that which is released into
the Great Lakes by other facilities (e.g., Detroit Edison)
relative to the many hundreds of toxins in the environment. . .
Consumers' Association
of Canada (Windsor)
Kingsville, Ont.
...tritium is absorbed by the human body directly from the
environment and is likely to produce stochastic effects
(comprising malignant and hereditary diseases) simply or as
synergistic effect along with other radioactive particles like
Cesium 137, Iodine 131, Radium 226, and Strontium 90.
61
Social Action Committee
Unitarian Congregation
of South Peel
Mississauga, Ont.
We are advised there are other radioactive substances in the
drinking water as well as other toxic material. Only ZERO
tritium is acceptable.
Individual
My second concern is the combination of tritium with other
toxic chemicals in the lake... I would like ACES to look into
this or recommend that it be further explored by the
appropriate agencies.
Individual
["The experts"] have not looked at the synergistic effect of
tritium with other pollutants.
62
Other routes of exposure
Name
Comments
Individual
It [tritium] can be ingested through the consumption of
tritiated water as well as directly through the skin.
Individual
...whilst ingestion is a major pathway, inhalation and skin
absorption will also play a part. I estimate that domestic
showering and bathing could contribute an additional 1 or 2
percent of dose and that inhalation and skin absorption of
tritium form indoor air whose humidity is partly evaporated
tap water could contribute an additional 5 to 20 percent. In
deriving a water quality objective, I believe these additional
pathways should be acknowledged.
Town of Whitchurch-
Stouffville
Stouffville, Ont.
My feeling is that I would not want to bathe a sick baby,
possibly with a skin rash, in water with a 7000 Bq/L standard
nor would I want my children to drink or swim etc. in such
water.
[Quoting from Wang, Willis, and Loveland, 1975] Deposition
of radioisotopes within the body... poses an entirely different
problem. In this case, isotopes whose radiation have very
short ranges are the most hazardous for they dissipate all
their energy with a very restricted volume of tissue. Thus
alpha emitters and weak beta (tritium type) emitters present
the greatest hazard...
Individual
...I use drinking water for bathing, and we know tritium is
absorbed through the skin. I also cook my food in the water,
I swim in my pool in the summer, I water my vegetable
garden with the water, and so on... we are also exposed to
high levels of ground tritium and air-borne tritium.
63
Bioaccumulation
Name
Comment
Individual
[in reasons for finding std unacceptable]... how they will
accumulate in the ecosystem, including humans.
Individual
...the half life of tritium is 12.3 years and is thus capable of
bioaccumulation in our ecosystems.
64
Organically bound tritium
Name
Comment
Individual
London, UK
on behalf of
Northumberland
Environmental Protection
Chronic exposures to raised concentrations of [tritium in
drinking water and air-borne tritium] may result in
organically bound tritium building up in the food chain to
ambient HTO levels, and in OBT contaminated food grown
near the nuclear facilities being eaten. The ingestion of OBT
is widely recognised as being more hazardous than the
ingestion of HTO... "the radiation dose delivered to specific
tissues, for example bone marrow, may be greater following
the ingestion of OBT by almost an order of magnitude as
compared to HTO" . It is recommended that studies be
carried out to ensure that food grown near nuclear facilities is
not consumed nor used as feedstuff s , and to ascertain the
levels of OBT in residents near nuclear facilities.
Energy Probe Research
Foundation
Toronto, Ont.
...the tritium in these organic compounds is much more [toxic
and carcinogenic than tritiated water]because it is much more
likely to incorporate itself into the molecular structure of our
DNA, our proteins, fats and carbohydrates...
Durham Nuclear
Awareness
Oshawa, Ont.
...tritium can also become organically bound to molecules in
the body, and this can result in a much longer biological half-
life.
65
RBE of Tritium
Name
Comment
Individual
London, UK
on behalf of
Northumberland
Environmental Protection
The Quality factor, recently reconfigured approximately to
the radiation weighting factor, for tritium remains at 1 ,
although considerable radiobiological evidence exists that it
should be increased to 2 and perhaps higher. The
evidence... of increasing RBEs with decreasing doses of
tritium is particularly worrying.
Environmental Protection
Branch
AECL Research
Chalk River Laboratories
Chalk River, Ont.
The RBE... is not a number carved in stone but can vary
appreciably depending on the system and the endpoint
studied. A high value in one particular system does not
negate, or even contradict, a lower value obtained in another
system. The RBE of a given radiation is the ratio of the dose
of the reference radiation required to produce a given level of
effect divided by the dose of the test radiation required to
produce the same level of effect. If tritium was more
effective, the denominator would be smaller than the
numerator; a RBE > 1 would result. The international
standard for the reference radiation is 200-250 kVp X-rays.
At low doses and dose rates (and protracted exposures),
however, operation of an X-ray machine is difficult and Co60
gamma rays are often employed... Considerable evidence
exists that the RBE for gamma rays referenced to X rays
becomes < 1 for low dose/low dose rate exposure; ...This
means that if tritium beta rays were, in fact, materially
indistinguishable in effect from X-rays, the beta rays would
appear to have RBE > 1 in reference to the gamma rays... an
apparent high RBE (value > 1) can result because the
numerator is higher not because the denominator is lower
(which would be the situation if the test radiation was more
effective, as a lower dose would suffice). This view is borne
out by a review of the AECB's Advisory Committee on
Radiation Protection : "Observed RBE values at low doses
and low dose-rates are usually about 2 to 3 when tritium beta
rays are compared to cobalt 60 gamma rays but are closer to
1 to 2 when compared to 200 kVp X-rays. This conclusion
is supported by microdosimetric considerations of the quality
of tritium beta rays, cobalt 60 gamma rays and X-rays."
Durham Nuclear
Awareness
Oshawa, Ont.
Cell and animal experiments indicate that the RBE value for
tritium should be at least 2, and that it may be as high as 5,
depending on which type of effect is being considered. This
means that tritium is likely 2 to 5 times more hazardous than
is currently accepted by the ICRP.
66
Dose conversion factor
Name
Comment
Individual
London, UK
on behalf of
Northumberland
Environmental Protection
...tritium's internal doses may be underestimated in three
ways. These are the use of a unconservative dose conversion
factors; the use of incorrect metabolic models which ignore
organically bound tritium; and the use of an incorrect Q
factor from radiobiological evidence... To be conservative, the
dose factor for HTO should be increased at least to the higher
values in the US [US Nuclear Regulatory Commission uses a
dose conversion factor of 3.4 x 10-11 Sv/Bq for ingestion and
2.2 for inhalation; US National Council on Radiation
Protection and Measurements uses 2.4]
Environmental Protection
Branch
AECL Research
Chalk River Laboratories
Chalk River, Ont.
...calculate the ODWO on the basis of the primary dose
conversion factor value, rather than on the basis of a
secondary value calculated form the dose conversion factor
and already rounded. This would give a value of 7600 Bq/L
as noted in [the Rationale Document], which could be
rounded to 8,000 Bq/L if desired.
67
Health effects other than cancer
Name
Comment
Individual
With cancer and birth defects rampant, we need to clean up
our Great Lakes and not add to the toxins already there.
Clean North
Sault Ste. Marie, Ont.
[MOEE considered only fatal cancer, other endpoints are
very important, such as immune effects, lupus, crones,
arthritis, etc. Morbidity must be considered, health is more
than the absence of death.]
Individual
The only effect mentioned in the report is cancer. What
about other effects such as old age diseases? The effects are
insidious and concerned that a generation of people are being
produced with an impaired ability to cope.
Individual
London, UK
on behalf of
Northumberland
Environmental Protection
...concern has been expressed about tritium doses near
DNA... tritium from tritiated food is capable of entering the
DNA molecule... the same is true from chrome tritiated water
ingestion... Another key point in the possibility of high pulses
of tritiated water resulting in the transient ingestion of high
levels of HTO...Commerford et al 1982, found after a
transient HTO exposure in mice, all the tritium remaining 8
weeks post exposure was bound to DNA and its histonc.The
half lives they found for DNA were extremely long... This
has implications for the diets of pregnant women living near
nuclear reactors discharging large quantities of tritiated water
and water vapour.
Durham Wetlands and
Watersheds
Oshawa, Ont.
Recent studies suggest correlations between higher
background radiation in [dw] and problems such as cancers,
birth defects, mental abnormalities and genetic defects.
Individual
Toronto, Ont.
...radioactivity in the body increases the risk of developing
cancer, other health problems associated with immune
deficiency as well as birth defects.
Durham Nuclear
Awareness
Oshawa, Ont.
the "end point" of interest should not be just death from
cancer. The dose of radiation that causes other health
impacts, such as birth defects, should be considered as well.
Individual
...what kind of baseline health analysis has been conducted
with regard to human health impacts of tritium in this area? I
refer not only to fatal cancers, but also to other impacts,
including such things as respiratory illness, sex organs of
males and females, fetal impact, etc.
68
Sault Area Nuclear
Awareness
Goulais River, Ont.
All exposure to radioactivity increases the risks of developing
cancer, and accompanying health problems. The cumulative
effects on descendant generations is highly debated by
industry, but has been proven to include birth defects and
sterility.
Individual
We see the Mongoloid children with their parents, or
sometimes in groups in the mall. Our daughter in law had
cancer but was operated on successfully. She is only 36 and
does not drink nor smoke.
Individual
[someone raised to this person that Dr. Petkau's work came
up at the deputation session] Most other international
scientists in radiation protection have in recent years agreed
that Dr. Petkau's studies are not directly relevant to presumed
effects of radiation on living organisms and have pursued
other lines of research.
Consumers' Association
of Canada (Windsor)
Kingsville, Ont.
...tritium is absorbed by the human body directly from the
environment and is likely to produce stochastic effects
(comprising malignant and hereditary diseases) simply or as
synergistic effect along with other radioactive particles...
Further quantitative estimates of the number of genetic
defects produced in the human population are usually arrived
at by estimating the proportion of individuals affected per
dose in fruit flies or mice and extrapolating the results to
humans. This imparts considerable uncertainties to the
results.
Town of Whitchurch-
Stouffville
Stouffville, Ont.
In addition to the five cancer deaths/million which in itself
must only be a statistical estimate, what about the other
illnesses precipitated by tritiated water. Was that factored
into the five year death figure or ignored?
Energy Probe Research
Foundation
Toronto, Ont.
...it would appear prudent to assume that tritium-apparently
the health dominant emission from those stations-is implicated
[in the excesses of Down's syndrome and childhood
leukaemia near Pickering and Bruce]
The risk estimates on which the ODWO is based assume,
contractually, that cancer is the only unfortunate health
effect of consuming tritium... and that tritium is the only
radionuclide (if not even the only carcinogen) in drinking
water.
69
Ajax Save the Waterfront
Committee
Ajax, Ont
Concerns raised regarding incidence in Ajax/Pickering area
of as outlined in AECB studies:
Down's Syndrome (86% higher);
five other infant abnormalities 25% to 71% higher:
limb reduction abnormalities;
ear, face, and neck abnormalities;
urinary system abnor.;
circulatory system abnor.;
ventricular system abnor;
infant death rates (2 to 5 times higher);
childhood leukaemia deaths (34% higher)
childhood leukaemia (34% higher);
damage to the immune system and genetic damage caused by
free radicals;
rate of prostate cancer in men.
Individual
[concerns expressed about incidence of Down's syndrome,
birth defects, infant standardized mortality ratios etc. in the
Pickering/ Ajax area]
[Proposes a supralinear dose response curve, with greater
effects at lower doses than a linear curve would predict;
outlines "The Petkau Effect"]A protracted exposure to
ingested beta emitters may be 1 .000 times more harmful to
cell membranes than a brief exposure to X-rays. The longer
the exposure, the smaller the dose needed to damage cells.
70
Feasibility
Cost Analysis
Name
Comment
Individual
[raises questions regarding the changes proposed and whether
they would have a significant reduction in pollution given
what the economic costs may be.] In this day and age of
cutbacks and economic uncertainty in the future, is what we
are doing going to be seen as another barrier to business?
C. Bruce Bigham
Consulting
Deep River, Ont.
...the most difficult thing was obtaining a reasonable balance
between safety measure implementation and cost. So my
major comment on the proposal is that I feel this has not been
studied adequately. It should not be 'beyond the scope' as
stated in Section 10. It is a critical issue.
American Water Works
Association
Toronto, Ont.
all reasonable efforts to improve drinking water quality and to
set drinking water standards based on a balanced evaluation
of documented health effects research, demonstrated
treatment techniques, and cost considerations.
Individual
No one can answer this question (is 7000 acceptable?)
without having considered... what are the costs? and what are
the expected benefits? If your government has not demanded
that you provide a documented risk-benefit analysis with your
recommendation it is behind the times.... Your advertisement
should have read "This std is expected to cost Ontario
households $xx per year net but will prevent initiation of an
estimated yy fatal cancers per year. Is that acceptable?" I
hope that the Minister will feel obliged to provide such cost-
effectiveness information when the standard is imposed.
Ontario Hydro
Toronto, Ont.
The public must be aware of the costs and benefits of this
guideline, [outlines the hypothetical costs and benefits of a
water plant closure if level reaches 7,000 for one
week]... then the benefit would be to have prevented the
public from receiving a dose of approximately 1.8 uSv....And
what is the cost to society? If an emergency is declared the
cost of activating the emergency plan will be quite
substantial. Furthermore the public becomes concerned about
the quality of their drinking water. Some may purchase
bottled water. Some may suffer anxiety. If Water Supply
Plants are shutdown, the public will be directly affected.
They may go without water. These costs are real.
71
Joint Committee on
Health and Safety
The Royal Society of
Canada
Toronto, Ont.
The first principle is that risks shall be managed to maximize
the total expected net benefit to society... The goal of any risk
mitigation effort ought to be the maximization of the net
benefit to society in terms of the length of healthful life for
all members at all ages... we would appreciate receiving the
studies that the regulator has performed that would show that
the detriments, in terms of public health impact, arising from
current levels of tritium are unacceptable... We also note that
reducing low levels of risk is expensive. Often, the societal
costs for reducing small risks to an even lower level can be
disproportionately high in relation to the benefit to be gained,
[enclosed Health and Safety Policies: Guiding Principals for
Risk Management booklet]
72
Water Treatment and Location of Drinking Water Plants
Name
Comment
Individual
...I am really concerned about the levels of tritium in our
drinking water... I hope the result [of the consultation] will be
such sound advice from the ACES Committee to the
Minister... that they will insist on the plant being moved to a
safer location.
Pickering Beach
Residents' Association
Ajax, Ont.
We urge you in your advisory capacity to the government to
insist on a safer location for this proposed water supply plant.
American Water Works
Association
Toronto, Ont.
...given that there is no treatment it may be more critical to
control discharges of tritium into the source water.
Bruce Peninsula
Environment Group
Lion's Head, Ont.
There is not... a choice available when it comes to drinking
water: it is clearly stated that tritium contained in water
cannot be readily distinguished... it also states that
conventional treatment is believed to be of limited
effectiveness for the removal of tritium.
Individual
We were very surprised at the information presented to you
(at the Feb. 16, 1994 deputation) particularly the fact that
tritium is in our drinking water, cannot be filtered or boiled
out and that there are substantial differences in "safe"
levels. . .
Consumers' Association
of Canada (Windsor)
Kingsville, Ont.
Whatever tritium level is drawn by intake pipes of water
purification plants are supplied to consumers in their homes.
Individual
...with no proven method of eliminating or filtering tritium
from water sources it makes enormous sense to prevent the
problem in the first place.
Town of Whitchurch-
Stouffville
Stouffville, Ont.
We should strive to minimize the health risk by removing the
source of higher levels of tritium or locating water supplies
that meet the existing levels.
Individual
A direction for the building of NEW water supply plants to
accept sites with the best probability of meeting a tritium
level of 2300 Bq/L.
73
Ajax Save the Waterfront
Committee
Ajax, Ont.
...we also encourage ACES to recommend to the MOEE that
no new water supply plant be constructed within 5 miles of a
nuclear generating station, which is the law in the United
States.
74
Implementation
Jurisdiction/Multiple water based standards
Name
Comment
Durham Nuclear
Awareness
Oshawa, Ont.
...the Seventh Biennial Report of the International Joint
Commission recommends that governments incorporate
radionuclides in their strategy for virtual elimination. This
means that tritium pollution must stop.
Clean North
Sault Ste. Marie, Ont.
[TJC has named tritium as a persistent toxin and therefore a
candidate for zero discharge]
Individual
In my opinion the focus should be: ... 1. the allowable
tritium releases to water by Ontario Hydro.
Individual
The recent International Joint Commission (UC) report
recommended that governments work towards the elimination
of any radionuclides with a half life greater than six months.
The half life of tritium is 12.3 years - 24 times longer than
the UC recommendation.
Durham Wetlands and
Watersheds
Oshawa, Ont.
The [TJC] has stated that only a zero tolerance level of
additional tritium in the [dw] of the Great Lakes is
acceptable.
Ontario Hydro Nuclear
Toronto, Ont.
It should also be noted that the AECB operating licenses
specify that the nuclear station must also comply wiht all
applicable provincial and local regulations. This implies that
we must comply with the most restrictive regulations in cases
where there is overlap of jurisdiction.
American Water Works
Association
Toronto, Ont.
...given that there is no treatment it may be more critical to
control discharges of tritium into the source water.
Atikokan Citizens for
Nuclear Responsibility
Mattawa, Ont.
Cynical persons, myself included, could come to the
conclusion that the MOEE are using an attempt at usurping
the AECB' s efforts to set stds as a strategy to conflict as
many jurisdictional layers of government as possible. These
jurisdictional conflicts effectively make any court challenges
as difficult, lengthy and expensive as possible. The MOEE
must forswear their old trick of using blurred jurisdictional
lines between the Provincial government and the Federal
government to excuse inaction or indifference.
75
Citizens' Network on
Waste Management
Kitchener, Ont.
In its Seventh Biennial Report on Great Lakes Water Quality,
the IJC recommends that the "Governments incorporate those
radionuclides which meet the definition of persistent toxic
substances in their strategy for virtual elimination." We ask
the province therefore immediately begin to develop a
strategy for eliminating the presence of tritium in water as a
result of human activities.
Individual
...substantial differences in "safe" levels, depending on which
side of the fence one is situated, i.e., AECL has adopted
210,000 Bq/L whereas our neighbours to the South have 700
Bq/L.
Individual
One of the most baffling aspects of standards for tritium in
drinking water is their proliferation and range. We have
identified at least 7 tritium concentration "limits", expressed
in Becquerels per litre that are variously quoted.... Which one
is "safe"? Are any? Will a new ODWO interim standard
make any difference to the other limits?
Ajax Save the Waterfront
Committee
Ajax, Ont.
The IJC is about to include radionuclides with a half life
greater than 6 months to their list of "persistent toxic
substances". The half life of tritium is 12.3 years. It
qualifies as a persistent toxic substance, and standards must
limit our exposure to it.
[Other discussions re: IJC' s "Precautionary Principle" and
"Principle of Reverse Onus".]
76
Monitoring
Name
Comment
Windsor Utilities
Commission
Windsor, Ont.
...we suggest that continuous monitoring be instituted and
guidelines established to prevent ingress of highly
contaminated water into the Great Lakes system.
Individual
[The report says that the] "Procedure for determination of
tritium in water begins with distillation of the samples. " Is
this a fair test? My understanding is that distilling the water
removes a degree of tritium from the water-is this the way to
do the test?
Individual
Ont. Hydro has still not developed a three dimensional
dispersion model... and as such no predictable pattern of
tritium dispersion can be evolved which will enable credible
sampling or tracking. No current reliable on line monitor for
tritium is available and development is still a long way off.
This status is even more significant since we are building a
New Water Treatment Plant on the Ajax waterfront, some 4-
5 km from the PNGS discharge.
Elgin St. Thomas Health
Unit
St. Thomas, Ont.
Although we have no comment on the specific standards
being proposed, we believe it is important that measurable
and meaningful levels should be established for any material
found in drinking water which may adversely effect public
health.
77
Transboundry sources
Name
Comment
Conservation Committee
Guelph Field Naturalists
Guelph, Ont.
...there are several plants on the US side doing the same
[releasing radioactive emissions]
Bruce Peninsula
Environment Group
Lion's Head, Ont.
Just think what a child born in 1993 would ingest with higher
and higher concentrations of tritium laced water, especially if
fate has put it in the Windsor-Detroit region where Detroit
Edison's Ferme nuclear plant is starting to dump millions of
litres of tritium laced water on a regular basis to Lake Eri.e.
Consumers' Association
of Canada (Windsor)
Kingsville, Ont.
Since the lake waters are used by nuclear plants in USA and
Canada, it would be advisable for both countries to consider
harmonization of standards.
78
Enforcement
Name
Comment
Atikokan Citizens for
Nuclear Responsibility
Mattawa, Ont.
Enforcement of future and present laws must be credible and
rational. Leave industrial development schemes, political
hand-outs and jurisdictional disputes OUT of the picture.
The FUNDS for strict enforcement and compliance should be
derived from the costs of producing nuclear electricity.
Individual
Also, improved objectives need to be accompanied by strict
enforcement. I believe citizens are tired of ineffective
'guidelines' and press releases stating "no immediate health
threat to the public", meanwhile the multitudes of cancer are
increasing.
79
Need For Additional Health Studies
Need for additional studies
Name
Comment
Individual
While a public review is laudable, the lack of research as to
low level exposure to radionuclides and its sudden elevated
levels in drinking water, I find to be quite distressing. In my
opinion the focus should be: ... 2. the effects of low level
tritium exposure to the populace. While I understand that
such studies will have a huge cost and will certainly not be
completed overnight, their implementation are long overdue.
American Water Works
Association
Toronto, Ont.
Although supporting data indicate that reported tritium levels
in Ont. drinking water are extremely low, the Section advises
that additional data would provide background levels for all
areas of the province.
Energy Probe Research
Foundation
Toronto, Ont.
ACES should... use its present mandate to conduct an
investigation of the phenomenon of a short term tritium pulse
in dw consumed by a pregnant mother being incorporated in
the ova of her female child.
Ajax Save the Waterfront
Committee
Ajax, Ont.
These three studies [AECB Down Syndrome etc, AECB
Leukaemia, Great Lakes Health Effects Program: Prostate
Cancer] show that there is an abnormally high incidence of
health problems in the Pickering/ Ajax area. We question if
this is just a coincidence, or can be dismissed as just
statistical aberrations. Where are the independent studies to
explain these occurrences in our area?
Individual
...there is little reliable information available on the effects of
many forms of radiation, of various strengths, affecting
various parts of the body. Only the government, which has
supported the nuclear industry form its inception, and has
promoted it at every opportunity, has the funding to do
conduct the necessary comprehensive studies to obtain such
information and... has refused to do so...
80
Other Comments and Recommendations
Name
Comment
The Beaver Valley
Heritage Society
Clarksburg, Ont.
Although we are interested in water quality, we have no
expertise in the chemical arena and therefore are unable to
contribute to your consultation.
York Region Public
Health Department
Newmarket, Ont.
...while we consider upgrading of stds to be beneficial our
technical knowledge... limits our capacity to suggest alternate
levels.
Ajax Citizens for the
Environment
Ajax, Ont.
...we are requesting a full tritium review before the new
Water Treatment Plant planned for Ajax is underway.
Clean North
Sault Ste. Marie, Ont.
[The Backgrounder refers to a "recommended dose", this is
misleading because it makes it sound as though radiation is
beneficial, like recommended daily vitamin intake. Dose
represents five fatal cancers, that should be clear in the
backgrounder.]
Walter Brown Associates
Environmental Planners
and Consultants
Mississauga, Ont.
A general comment is the proposed ODWO is an exercise in
futility because:
a)Ont Hydro is the only source of tritium... only in
conjunction with a spill... at $300/kg Hydro is not likely to
have many spills
b)lakes have a large dilution factor
c)bkgd levels have not been factored in.
Individual
I suggested it would be useful to obtain information about
standards or guidelines used in other Western countries, such
as the U.K., France or Germany, and the rationale for these.
...I expect ACES will have taken appropriate action to obtain
this type of information for themselves.
Northumberland
Environmental Protection
We are therefore formally requesting that the ACES
Committee recommend to the government that a full review
process be set up...
International Geochemical
Mapping Project
c/o Geological Survey of
Canada
Ottawa, Ont.
...until the natural variations are properly established by
systematic mapping there is a serious risk that
administratively prescribed limits for "contaminants" may be
unrealistic and could cause unnecessary alarm, litigation, and
economically damaging consequences.
Individual
...you as a government will have to believe both sides [one
saying there is no problem, the other saying there is] and take
a middle viewpoint of both. Do not trust one or the other,
not either or.
81
Conservation Committee
Guelph Field Naturalists
Guelph, Ont.
[concerns re:ecosystem effects]... many wildlife have to
survive in this water year round.
American Water Works
Association
Toronto, Ont.
where decisions regarding resource use and resource
development include alternatives adversely affecting the
quality of the drinking water supply sources, preference
should be given to the alternatives that protect or enhance the
quality of the protected source.
Community Liaison
Group
Siting Task Force
Low Level Radioactive
Waste Management
Deep River, Ont.
We cannot provide comments or recommendations on
environmental issues as it is not in our mandate to do so. We
cannot, therefore, assist you in this review.
Citizens' Network on
Waste Management
Kitchener, Ont.
We find it disturbing to compare sources of radiation and say
that tritium intake accounts for less than 0.1% of overall
exposure. It isn't general exposure that matters most. Stds
must be set for those who are subject to the highest exposures
and receive higher than average intake... We can't do much
about the natural sources. Therefore we must focus on those
things we can do something about.
Individual
[following some criticisms of the document] I respectfully
suggest that future Rationale Documents used by ACES
follow a specific format which includes: a statement of the
population of concern, a definition of the critical endpoint,
and the calculation of the criterion. This would make the
review of the document easier to do.
Bruce Peninsula
Environment Group
Lion's Head, Ont.
We also strongly urge ACES to expand their advisory activity
in taking a stand on eliminating all sources of tritium
emission, most notably the aging nuclear reactors which
should be taken out of service at the earliest possible date,
seeing that there is overcapacity at Ontario Hydro.
Durham Nuclear
Awareness
Oshawa, Ont.
We would like to recommend that ACES contact an
independent expert for an opinion on suitable dose conversion
factors,...
Ontario Hydro
Toronto, Ont.
...the drinking water objective must be used appropriately, in
a fashion which represents true impact. ...This is our main
concern: What use will be made of the drinking water
objective? The rationale document quotes on page 14 exactly
how the international scientific community intended this
objective to be used... The [WHO recommended] that the
level be used as a trigger to initiate further investigations.
82
University of Toronto
Toronto, Ont.
[recommends clarification in wording of Rationale Document
re: consumption level and duration and dose as well as
spelling and grammatical errors] I have no objection to the
WHO guidelines nor the Canadian or Ontario equivalents and
can only emphasize that they must be applied rationally.
Individual
...the release of tritium into the natural environment will
indeed impact other life forms... minimizing tritium could be
very significant for entire ecosystems...
[Comparisons with background-2 concerns]... 1. the date on
which natural bkgd was determined [should be pre-nuclear] 2.
[thinning of the ozone may create more tritium in the upper
atmosphere]
Bkgd tritium as a beta particle is incapable of penetrating the
outer layer of skin but tritiated drinking water is uniformly
distributed among all of the soft tissues of the body. Is this
not a potentially greater threat?
Energy Probe Research
Foundation
Toronto, Ont.
[recommendations for emission controls e.g. via BAT or
BATEA instead of ODWO] 1. ACES should urge the
Minister to begin treating tritium as a priority
pollutant... either by adding it to the Emissions Monitoring
Priority Pollutants List and monitoring and controlling it
under MISA regulations, or by adding it to the Candidate
Substances List for Bans or Phase Outs. In our view... either
of these outcomes would be more appropriate and more
beneficial... than any attempt to control human ingestion
solely through an ODWO.
4. In its report to the Minister ACES should endeavour to
correct the many false and misleading statements in the Rat.
Doc, and should attempt to ensure [it is circulated]
From March 10, 1994 submission: inclusion of tritium in
Ontario's Effluent Monitoring Priority Pollutants List (of
which radionuclides are expressly excluded) and/or Candidate
Substances List for Bans or Phase-Outs. [Comparisons of
acceptable risk level from ACES' s recommendations re:
NDMA and tritium risk levels] ACES should not adopt a
double standard of acceptable risk.
General support of increasing water quality; interested in the
designation of springs as heritage sites.
Individual
83
Pickering Ajax Citizen's
Together for the
Environment
Pickering, Ont.
1 . We feel that the tritium issue deserves a thorough
investigation, and that participant funding, and if warranted,
intravenor funding be made available to all parties.
2. The ACES report should be distributed to the public on
the same day the Minister receives his copy, and that the
minister review this report within a reasonable period of
time.
Individual
feels that setting standards based on risk assessment is not
sound and provides a rationalization to continue to produce
tritium, keep people employed etc. Any risk analysis is not
worth it
Individual
There appears to be no known rationales for tritium targets of
allowable levels, be it 40,000 Bq/L, 7,000 Bq/L or the U.S.
of 2,300 Bq/L.
84
Appendix 4: Letter from Dr. Waight, Health Canada
FACSIMILE MESSAGE/BELINO
RADIATION PROTECTION BUREAU
BUREAU DE LA RADIOPROTECTION
775 Brookfield Road «
Ottawa Ontario
K1A ICI
TO/A: MS C. BENNETT
ADVISORY COMMITTEE ON
ENVIRONMENTAL STANDARDS
FROM/DE: DR. PL WAIGHT
NO OF PAGES/NO. DE PAGES: TWO
MESSAGE:
DEAR MS BENNETT,
THANK YOU FOR YOUR FAX WHICH I RECEIVED THIS
MORNING. AS FAR AS THE PROPOSED ONTARIO STANDARD IS CONCERNED,
7 kBq REPRESENTS AN ANNUAL DOSE OF 0.0919 mSv, BUT I WILL ASSUME A
DOSE OF 0.1 mSv FOR THE PURPOSES OF THIS REPLY; LC
THE NOMINAL PROBABILITY COEFFICIENT FOR FATAL CANCER
INDUCTION IS GTVEN BY 1CRP IN ITS PUBLICATION 60 ON PAGE 70 AS
5 lO2 Sv1. THUS FOR 0.1 mSv RECEIVED ANNUALLY, THE TOTAL LIFETIME
RISK WOULD BE
5 105X0.1 X70 = 3.4 10"
TO PUT THIS IN PERSPECTIVE IT IS PERHAPS USEFUL TO COMPARE IT WITH
THE LIFETIME RISK OF DYING OF CANCER IN THE CANADIAN POPULATION.
THIS IS 26.38% FOR MALES AND 22.20% FOR FEMALES (CANADIAN CANCER
STATISTICS 1992 PAGE 27). ASSUMING THAT THERE ARE EQUAL NUMBERS
OF MALES AND FEMALES IN CANADA, THEN THE AVERAGE RISK WOULD BE
24.29% OR ABOUT ONE IN FOUR. THE DOSE OF 7 mSv WOULD ADD A RISK OF
ABOUT ONE IN TWO THOUSAND NINE HUNDRED TO THIS RISK OF ONE IN
FOUR. THIS IS AN ADDITIONAL RISK OF 0.034% TO THE EXISTING 24.29%.
OTHER COMPARISONS CAN BE MADE:
THE AVERAGE EXPOSURE FROM BACKGROU N D IS ABOUT 2 . 8 mSv y* , OR
196^ mSv OVER 70 YEARS, COMPARED WITH THE DOSE FROM THIS
HYPOTHETICAL SOURCE OF 7 mSv.
THE O.lmSvlS ALSO WELL WITHIN THE ANNUAL FLUCTUATIONS IN THE
85
DOSE FROM BACKGROUND.
THE OTHER POINT THAT IS PROBABLY WORTH MAKING IS THAT
BECAUSE A LIMIT IS SET, IT DOES NOT MEAN THAT THIS LEVEL WILL
AUTOMATICALLY BE REACHED. THE CURRENT LEVELS OF TRITIUM IN
DRINKING-WATER RANGE FROM NON-DETECTABLE TO A MAXIMUM OF 50
Bq/I CLOSE TO A NUCLEAR POWER STATION. THE INTRODUCTION OF A 7
kBq LIMIT WILL HAVE ABSOLUTELY NO IMPACT ON THIS LEVEL.
I AM A LITTLE CONCERNED THAT TRITIUM IN DRINKING-WATER IS
BEING CONSIDERED IN ISOLATION FROM OTHER RADION UCL1DES. THE WHO
GUIDELINES ARE FOR ALL RADIONUCLIDES, NATURALLY OCCURJNG OR
MAN-MADE, NOT TO EXCEED THE COMMITTED EFFECTIVE DOSE OF 0.1 mSv
FROM ONE YEAR'S INTAKE.
I HOPE YOU FIND THESE COMMENTS USEFUL.
SIGNED:
DATE: 14 MARCH 1994
86
Appendix 5: U.S. EPA's Science Advisory Board paper entitled Harmonizing
Chemical and Radiation Risk Reduction Strategies-A Science Advisory Board Commentary
HARMONIZING3 CHEMICAL AND RADIATION RISK-REDUCTION '
STRATEGIES-A SCIENCE ADVISORY BOARD COMMENTARY
Introduction
Risk assessment and risk-reduction strategies for radiation have developed
•within a markedly different paradigm than has been the case for chemicals. Radi-
ation risk assessment has been based largely on observations in humans exposed to
relatively well-known doses of radiation, while chemical risk assessments are much
more often based on projections from experiments with laboratory animals or on
human epidemiology with relatively uncertain determinations of exposure. Perhaps
more importantly, radiation risk-reduction strategies have developed almost from
the start under the assumption that it would be necessary to balance these risks
against the benefits of radiation or radiation-producing technologies, all within an
environment that included unavoidable natural sources of background radiation. By
contrast, chemical risk-reduction strategies evolveded from an initial assumption,
developed early in this century for food additives, that public health could be
completely protected. Only in the 1960s did a balancing approach become well .
established for chemicals, and (in retrospect) even then it was aimed at reducing . .
risk to levels that would be considered low by almost any criterion, thereby favoring
protection of health more than did the radiation paradigm. Furthermore, for many
chemic?ls, significant natural sources were either absent or given relatively little
consideration.
The discordance or lack of harmony between these different paradigms was
not particularly evident until the Environmental Protection Agency (EPA) started to
deal with radiation issues in the context of decisions that also needed to be made '^
about chemicals, for example with respect to radionuclides as hazardous air pollute
ants under the Clean Air Act, or at hazardous waste sites, or in drinking water'
supplies where chemicals are also present. The application of standard chemical
risk-reduction criteria to radionuclides in these situations leads to limitations on
excess radiation dose that are small in comparison to natural background radiation.
Knowing the history of the radiation paradigm, it should come as no surprise that
some radiation scientists see such limitations on radiation exposures as unworkable
or even misguided. Some chemical risk assessors who observe radiation protection
Aj applied to environmental management, 'harmonizing' i* * word used extensively in Europe but not as much in the
United States. Harmonization does not require that all environmental policies be identical or even wholly oontittent; policiea
«re in harmony when they are »e<n aa in nine with en overall «trategy and not discordant.
87
guidelines corresponding to risks greater than one in a thousand are similarly
puzzled: how can such high absolute risks be tolerated?
Given this situation, some resolution of the discordance between the two
paradigms is needed. The resolution could simply be to assert that radiation and
chemicals are fundamentally different and should be assessed and managed differ-
ently, or some synthesis could be reached that takes into account both background
issues and absolute risk levels. As an example of the latter approach, Kocher and
Hoffman (1991) have recently proposed a specific risk management strategy that
may be applied to both radiation and chemicals. The following sections describe the
radiation and chemical paradigms in more detail and suggest some possible ap-
proaches to resolve the discordance between them.
The Radiation Paradigm
Current risk assessment approaches for radiation, whether from radionuclides
or from other sources, developed out of the atomic energy program. It both served
as a framework for radiation protection for atomic workers (and later for the gener-
al public) and, under the rubric of "damage assessment," was used to predict fatal-
ities and residual health impacts from the radioactive fallout from nuclear weapons.
In assessing risk, health physicists, radiobiologists, and radiation epidemi-ologists
have been able to make risk estimates of relatively high precision from human data.
While cancer risk estimates for radiation entail substantial uncertainties, especially
at low doses and dose rates, they are seen as being sufficient to justify making a best
estimate of risk within a statistical uncertainty factor of about 2 for all cancers com-
bined for whole-body external radiation if the dose is known accurately (NCRP,
1989). These best estimates of risk are used directly without further safety factors,
of any kind. Because best estimates are used and the degree of uncertainty is only
moderate, risk assessment results for radiation can be compared with risk criteria
for control decisions with some confidence.
Radiation risk assessment was heavily influenced by the thinking of physi-
cists; in fact, "health physicists" are more likely to be involved in the practice of
radiation protection than are the "radiobiologists" who study the fundamental bio-
logical aspects of radiation. Typically, the description of radiation risks emulated
the mathematical treatments of physical systems, often using phénoménologie
Radiation scientists generally aclcnowledge that no ûnn conclusions «doth risk can be Tr.ade for total dc*es below about
10 rem. If the liinr dose-response hypothesis is accepted for low-dose extrapolation, however, the risl estimates are
relatively precise. In this report the units of rad and rem have b«n used rather than the corresponding ST units of Gy "■■^ Se.
Tor conversion to the latter units all numerical values are divided by one hundred.
models with consideration of biological theory only as a secondary factor. The fit of
curves to cancer data from radiobiological experiments were interpreted as reflecting
linear, simple quadratic, or linear-quadratic dose-response relationships, and the un-
derlying mechanisms were described by "target theory" as "one-hit" or "two-hit" and
so on. Later, it was postulated that radiation created breaks in DNA which, if not
repaired, .could result in somatic mutations and eventually in cancer. While it is
now believed that additional mechanisms — e.g., radiation effeds on oncogenes —
may play a role, the mutation hypothesis for radiation carcinogenesis still heavily
influences radiation risk assessment and management (NCRP, 1989).
The analysis of epidemiologic information followed similar models, whether
the data were from acute doses of whole-body gamma irradiation (Hiroshima and
Nagasaki), fractionated X irradiation (tuberculosis patients, for example), or
protracted irradiation from internally deposited radionuclides (the radium dial
painters and the uranium miriers). Issues arose about the existence of thresholds
for radiation carcinogenesis (e.g., in the dial painters) or at least "practical thresh-
olds" (e.g., the idea that cancer latency was inversely related to dose such that
manifestation of risks at low doses could be delayed so long that no cancers would
occur during a normal lifetime).
Underlying all this development was the knowledge that background expo-
sures to radiation in the range of about 70 to 250 millirem per year (mrem/yr) and
averaging perhaps 100 mrem/year dose equivalent (NCRP, 1987) were inescapable.
At least initially, these background exposures were generally assumed not to confer
significant risks. Thus, as recommended radiation standards became more strin-
gent with the discovery of adverse effects at ever lower levels of protracted exposure,
the radiation scientists kept in mind the difficulty of separating excess exposures
from natural exposures when the former did not substantially exceed the latter. ■ '
Consequently, cancer risk-reduction strategies for excess radiation exposures have '■■,
very probably included comparison to background radiation in addition to the
comparison of risks and benefits resulting from radiation-producing technologies,
even though the background exposure issue has usually not been explicitly presented
in such decisions.
When in the early days the critical endpoints for radiation protection were
effects seen only at what are now considered to be high (e.g., erythema) doses, the
allowable excess doses were easily separable from normal variability in background
radiation. The standards have been tightened as the assumption of ho threshold for
radiation carcinogenesis and the possibility of a linear dose-responsé relationship '
have taken hold among most radiation risk assessors. These assumptions have been
89
employed in the development of radiation protection policy. Scientists have also
learned, however, that many people are experiencing exposures to the lungs from
radon and its progeny that confer risks several times that from the 100 mrem/year
that arises from cosmic radiation, terrestrial gamma radiation, and internal potassi-
uro-40 radiation, averaging perhaps 200 mrem/yr (NCRP, 1987). And, a; least for a
time, medical diagnostic and therapeutic radiation increased the average radiation
dose about 100 mrem/year on the average.
The Internationa] Commission on Radiological Protection (ICRP) currently
recommends limiting excess environmental radiation exposures to a total of 100
mrem/yr for the general population flCRP, 1991). In addition, the ICRP requires
that there be a net positive benefit and that the ALARA principle be adhered to that
is, that exposures should be kept As Low As Reasonably Achievable when economic
and social factors have been taken into account. The ALARA concept appears to be
the radiation protection community's equivalent of feasible technology-based
standards for chemicals.
The potential cancer burden from 100 mrem/yr exposure is not always made
explicit in radiation protection guidance. If continued over a lifetime, however, 100
mrem/yr is calculated with EPA's current risk coefficient for radiation carcinogene-
sis to cause cancer risks of almost 3 in a thousand (3 x 10 ) (NAS/NRC, 1990).
Some analyses would predict risks up to three times higher, i.e., close to one in one
hundred.
The Chemical Paradigm
For chemicals, the paradigm is different!- 1 Most cancer risk assessments are
based on the results of bioassays in animals closed rwith chemicals at levels thou-
sands of times those expected in the environment, not from human data of high
reliability. To deal with the uncertainty, EPA in particular has adopted the use of
the upper confidence limit on the slope of the linearized multistage model to project
risks at low doses and has used a conservative procedure - the surface area scaling
rule — to project from animal bioassays to assumed human responses. Both of these
procedures are widely believed to produce risk estimates that are more likely to
overestimate than underestimate human risk (EPA 1986; 1989). Thus risk esti-
mates for chemicals are biased high (even though such may not be the case with
every chemical). This conservative method of dealing with uncertainty ensures that
in the vast majority of cases, the actual risk level achieved will be lower than the
risk criterion used in a control decision.
90
Furthermore, the prototype chemical carcinogens were synthetic substances
with no or limited natural sources. In calculating excess risk from human sources of
a chemical, background levels, if any, are therefore frequently seen as irrelevant,
even though in actuality background levels from either natural sources or anthropo-
genic sources other than the one being considered often exist.
Risk assessment for chemicals developed from the ideas of medical epidemi-
ologists, biostatisticians, experimental biologists, and - perhaps most importantly -
public health regulators. Again the idea was to protect people from the adverse
effects of chemicals on health, most particularly potential carcinogenicity. Here the
tradition was chemical safety, deriving from the early food and drug protection ideas
to keep chemical exposures low enough to protect health with a substantial margin
of safety. This was typically accomplished by finding some "no-effect level" and then
dividing by "safety factors" with the goal of achieving nearly absolute safety. This
approach is still, used for non-carcinogenic chemicals.
The idea that some chemicals might be a little dangerous at any level of
exposure (the no-threshold idea, applied especially to what were then called "radio-
mimetic chemicals") came as quite a shock to the regulators. Congress responded in
1958 by attaching the "Delaney Clause" to the amendments for the Food, Drug, and '
Cosmetics Act, which prohibited the addition to the human food supply of any
chemical that can cause cancer in humans or animals. The idea remained to provide
absolute protection against cancer risk.
From the start, however, FDA scientists and others realized that assuring
complete absence of carcinogens in the food supply was impossible, particularly in
view of the rapidly advancing ability of the analytic chemists to detect ever lower
levels of chemicals in food, and the abundance of naturally occurring carcinogens. .
Almost from the outset of the Delaney era, therefore, the FDÂ was looking for the '~
practical equivalent to absolute safety in a world where thresholds for carcinogenesis
could not be assured. FDA and NIH scientists soon proposed that if risks calculated
under the no-threshold assumption were below some small value, the carcinogen was
effectively not present in the food and the Delaney Clause would be satisfied. The
first proposal for a "virtually safe dose" was to limit cancer risk to one in 100 million
(10**) over a lifetime of exposure (Rodricks et alp 1987). The idea was clearly tied to
the assumption that all the people in the United States could be exposed at or near
the virtually safe dose; at the then-current population of about 150 million, only one
or two people currently alive could be affected even if all the conservative assump-
tions about exposure and potency proved to be true.
91
Shortly thereafter, it was realized that the 10 criterion itself put an almost
impossible burden on the regulator for assuring the safety of food additives with
considerable benefits. Almost as a reflex, the idea arose that one in a million (10 )
was a lifetime risk that most people would find negligible. At that level, everyone in
the nation could be exposed and only about 3 excess cancer cases per year would be
incurred, again even if the risk estimates were accurate and not conservative. Given
that everyone would not be so exposed if one calculated the risk for a reasonably
highly exposed person, the resulting cancer toll would clearly be invisible and, for
most people, the risk insignificant.
Although quasi-scientific arguments have been offered to justify the one-in-a-
million criterion for acceptable risk, we must not forget that it originated as a
number of convenience. Nevertheless, it became institutionalized over the next
several years and, when cancer risks from environmental exposures became recog-
nized in the late '60s and early '70s, the concept of negligible risk at 10 was
3 ^
applied there. Early on, the types of risks of most concern were widespread ones
such as exposures to PCBs or pesticide residues in the environment. Later, the
same risk criteria began to be applied to much less widespread risks such as around
industrial facilities or hazardous waste disposal areas.
Eventually, it became evident that 10 was a very stringent criterion when
relatively few people were exposed. Studies of EPA decision-making show that EPA
often has chosen not to require reductions in exposure when the calculated risks
were as high as 10 or even 10 when the population exposed was small (Travis et
al., 19S7; Rodricks et al., 1987)."
Moreover, some of the statutes that govern chemical regulation by EPA and
other agencies allow or even require a balancing of the risks against the benefits of
the technologies involved and the cost of control strategies in determining what risk
is acceptable in a specific situation. Others simply demand action whenever risks
are determined to be "substantial" or "significant," and many judicial battles have
been fought over the meaning of these directives. For example, in the Vinyl
Chloride case litigated under the Clean Air Act, the court ruled that chemical safety
did not imply a complete and unambiguous freedom from risk, but also that the
This level cf risk hmititicn was cot, and «till is Dot. required is the occupational health arena where, both by rireue of
arguably ■voluntary risk and by precedent fron non-cancer risks, a lifetime risk criterion of about one in a thousand if
considered reasonable for occupational exposure to carcinogens (See Rodricks et al, 1967, pp. 31<). Xven in the occupational
arena, however, radiatic:: eposure limits are less restrictive in risk terms than are chemical exposure limits. Currently
allowable radiation doses, if actually incurred, would lead to a lifetime risk cf well over one in a hundred, perhaps reaching cne
in ten (See NaS/NHC. 1990. pp. 172).
92
primary safety decision had to be made without considering benefits and control
costs (Whipple, 1989). Later, risk/benefit balancing could be applied in determining
an adequate margin of safety. Such risk-benefit balancing is conducted in the same
spirit as the optimization principle in the radiation community, but at a different
balance point, with radiation protection requiring lower expenditures per. cancer
avoided.
Recently, Don R. Clay, EPA's Assistant Administrator for Solid Waste and
Emergency Response (which includes the Superfund program) has indicated that
remediation at hazardous waste sites need not be undertaken when cancer risks for
lifetime exposures are calculated to be below 10 (Glay, 1991). Cancer risk levels at
or above 10 are also accepted in setting Maximum Contaminant Levels (MCLs) for
carcinogens in drinking water (e.g., for chloroform from water disinfection) when
limiting them further is not technically or economically feasible. Even so, many
EPA programs still apply a risk criterion in the 10 to 10 range to a (sometimes
only hypothetical) "maximally exposed individual" or "reasonable maximum expo-
sure." This "individual risk" focus does not place as much weight on the overall
protection of public health (individual risk times number of people exposed at that
risk level) as does a "population risk" focus. Whether the Agency's judgment is
focused on individual risk or on population risk for a specific situation depends on
the provisions of the enabling legislation and the traditions of the EPA office imple-
menting it. Risk-based legislation is more likely to result in an individual risk focus,
whereas technology-based standards to some extent skirt the individual risk issue
and implicitly favor a population risk approach.
Some chemical regulators and environmentalists are convinced that risk
levels above one in a million are not acceptable for any person, invoking arguments
regarding equity: why should any person bear à cancer risk for the benefit Of other-
people? Why should all people not he afforded -equal- protection? • Why should
carcinogens be allowed in i.ie environment at all?- And everyone would agree that -
all opportunities to reduce risk should be seized as long as the costs — economic,
social, or other — are not too high.
Progress toward such goals is much easier to measure when there is no
natural background exposure. Synthetic organic chemicals often would not be
observed in the environment at all if not for human activities; even when natural
93
sources can be identified, the risk levels for the natural levels of exposure are often
not high when calculated with the linearized multistage model or an equivalent.
Notwithstanding these similarities to the radiation paradigm, the chemical
carcinogen paradigm tends to view any risk levels above 10 , even to a very few
individuals, as potentially excessive and therefore requiring action to reduce
exposure and risk.
Discordance between the Paradigms
Although similarities and differences in risk assessment techniques for
chemicals and radiation have been discussed, (NCRP, 1989) and although the
difference in the risk-reduction strategies between these two paradigms has been
recognized by some scientists and regulators for several years, the provinces of the
health physicists and the chemical risk managers stayed relatively distinct until
recently.' As the EPA gradually took on greater and greater responsibility fcrr
regulating radiation sources as well as chemical ones, the discordance became more
visible.
The difficulty became evident in several EPA program areas. When EPA had •■
to promulgate National Emissions Standards for Hazardous Air Pollutants
(NESHAPs) for radionuclides, it needed to harmonize the residual risk levels with
those allowable for other carcinogenic air pollutants such as benzene. In the course
of analyzing sources of airborne radionuclides, more stringent controls were pro-
posed for them than would have been thought necessary to keep radiation doses to
100 mrem/yr or somewhat less. Furthermore, EPA had to wrestle with the fact that
. prior emissions from (or other practices of) these facilities may have left residual
radioactivity "in communities across the country producing radiation doses with
calculated risks greater than one in ten thousand.- The Radiation Advisory Commit-
tee (SAB, 1992a) recently commented on the Idaho Radionuclides Study, in which
some people may have received excess gamma radiation of the same magnitude as
typical background radiation levels, i.e., about 100 mrenvyr, from uranium-series
radionuclides in elemental phosphorus slags distributed in their community.
Elsewhere, EPA is dealing with radon emanations from phosphogypsum stacks or
with radionuclides from processing of rare earths for radium, thorium, or non-
radioactive materials.
In a few irtuaticns - arsenic in drinking water cornea to mind — the calculated risk levels of natural apocure are high.
In «ruch cases, the idea of comparison to background of chemical carcinogens if mere likely to be invoked, often by stipulating
that there is no excess exposure if measured concentrations are not beyond the confidence limits en the distribution cf
background ccncentrivicns-
94
A second area of discordance grew out of the recognition of waste problems
involving radioactive materials that were under the purview of EPA or state
environmental agencies rather than the Nuclear Regulatory Commission or the
nuclear/radiation safety agencies in agreement states. The most striking of these
are the radioactive or mixed waste problems at sites that have been placed on the
National Priority List for attention by the" Superfund Program. Here the wastes of
most concern are often the radionuclides of the uranium or thorium series that are
also found in nature, and which have for the most part been "technologically
enhanced" by human activities, rather than created by them.
The facilities of the Department of Energy that are part of the nuclear
weapons complex form another group of problem sites where radionuclides are a
significant or even dominating part of the cancer risk equation. Whether these
facilities are treated as Superfund (CERCLA) problems or current waste disposal
sites under the Resource Conservation and Recovery Act (RCRA), the treatment of
radioactive materials is seen as necessarily being subject to the same types of risk
analyses and remedial responses that EPA has used for chemicals. The document
"Risk Assessment Guidelines for Superfund" (RAGS), for example, contains a section
on how to assess the cancer risks from exposure to radionuclides, but does not
suggest any different risk-reduction strategies than for carcinogenic chemicals. The
implication is that remediation is expected if the lifetime risks from radionuclides
are calculated to exceed about 10 (or lower in some proposals for radiation sites).
The differences in the radiation and chemical paradigms have also become
apparent in EPA's actions with respect to radon in homes. The current EPA
guidance Taction level") for home remediation is 4 pCi/L of radon in air in the ,
lowest lived-in area, which by current EPA risk assessment methods translates to a
lifetime risk of over 1 in 100 or 10,000 in a million (1x10 j for an average person
(smokers and nonsmokers combined) (ERA, 1991a). The Agency. is clearly, not ;-. ->
implying that such a level of risk is acceptable in an absolute sense,- but appears to .-
be applying a rule, of practicality based on the difficulty of reducing exposure levels
much below 4 pCi/L within a reasonable budget. EPA also must work on the radon
issue without a clear legislative mandate encouraging the Agency to regulate
homeowners' choices.
EPA has reacted differently to the legislative requirement to control levels of
radon in drinking water. Using an approximation of the chemical paradigm, the
Office of Drinking Water has proposed that public water utilities must treat water
that contains radon above 300 pCi/L (EPA , 1991b), a level yielding a risk in the •
vicinity of one in ten thousand (1 x 10 ), even though this level of risk is two orders
95
of magnitude lower than what is recommended for radon in air and the cost per
calculated life saved is substantially greater than for remediation of radon in
household air (SAB, 1992a).
It can be argued that the discordance between radiation and chemical risk-
reduction strategies is simply another manifestation of necessary differences in'
regulatory choices in different situations. Indeed, good reasons exist to make all
risk-reduction decisions within a framework intended to reduce overall risk levels
without excessive attention to keeping the risks from any one situation within
inflexible guidelines. Clearly, the requirements of the various statutes enabling
EPA's regulatory activities force the Agency to formulate and apply some discordant
and seemingly inconsistent policies. Nevertheless, the Committee believes that the
differences between the chemical and radiation paradigms are more troublesome
than the variation within each area of regulation.
In each new case of radiation risk management, EPA can follow the chemical
tradition of regulating risks to the vicinity of 10 or lower or the radiation tradition
of tolerating (where inexpensive remedies are not readily available) an approximate
doubling of the risks from natural background radiation, which are in the vicinity of
3 * 10 for background exclusive of radon and nearly one in a hundred (10 j when
radon is included. This disparity can and has led to considerable lack of under-
standing and conflicts between health physicists and chemical risk managers. Even
the existence of an analogy in the chemical world to the radionuclide problem — the
background levels of carcinogenic inorganic substances such as arsenic and the
existence of substantial quantities of natural organic carcinogens in foods (Ames and
Gold., 1990)- has not brought about any resolution of this discordance.
Need for Harmonization
Clearly, EPA needs to adopt policies that will allow its staff, the regulated
community, scientific consultants to both parties, and the general public all to know
what to expect in EPA's regulation of residual radioactivity and other radiation
issues. The Radiation Advisory Committee does not claim any special insight in how
the resolution should be accomplished, but does emphasize the importance of
achieving such harmonization. Interest in the comparative risks of radiation and
chemicals has a substantial history (NCRP, 1989) and is now becoming more
widespread (Kocher and Hoffman, 1991).
One approach could be to assert that radiation and chemical regulations are
fundamentally different, perhaps because of the unavoidability of background
96
radiation. The guidance of the ICRP on dose limitation (currently, 100 mrem/yr
whenever the ALARA principle does not result in lower levels) could become the
explicit policy of the Office of Radiation Programs (ORP), and other branches of
EPA could explicitly defer to ORP on radiation and radioactivity issues.
A second set of alternative approaches would strive for clear consistency
between the radiation and chemical risk-reduction strategies. .The two extreme
cases are:
a. Use the optimization principle along with background risks from
radiation as guidance for how much excess risk can be tolerated from
any source, be it chemical or radiation. Excess risks in the range of
10 or a bit higher would be used as a criterion for remedial actions or
regulations where remediation is expensive and not easily achieved.
Use the ALARA principle whenever it applies, that is, when risks can
• be reduced without excessive penalties in terms of social or economic
costs. Make provisions for dealing with hazards in those cases where
exposures even at the calculated 10 risk level are not detectable or
distinguishable from background (i.e., ALARA should apply whenever ,-
risk reduction can be reasonably anticipated even though it cannot be
measured). . .
b. Regulate radiation risks exactly as chemical risks are now regulated.
Use 10 as a standard criterion for remediation or regulation, regard-
less of how the corresponding standards compare with background
levels of exposure. Use the absolute value of risk in excess of back-
ground risk as a criterion, not the fractional increment relative to.
background risk. Make practical exceptions for the inability to detect
some of the regulated exposures at thé selected level of risk, just as is
done for chemical substances when the detection limit exceeds the :
target for regulation, as is the case for dioxin in water. Take costs and
benefits into account where the applicable legislation provides for that .
possibility.
The Radiation Advisory Committee recognizes that neither of these latter
options may be practicable given the history of how the two paradigms developed.
Probably more likely to be accepted would be a third option that seeks a compromise
risk-reduction strategywith an intermediate risk acceptance criterion or criteria.
97
As a third option, the Agency could determine that, because the physical
characteristics of the two types of agents are so different and because the approach-
es to monitoring and regulating them have developed so differently, bringing the two
fxeas into rigid conformity in the near term is very likely not possible, however
societally or ethically desirable as a long-term goal The Radiation Advisory
Committee strongly suggests in this case that the two approaches be harmonized—
that is, fitted into a common policy framework aimed at aggregate risk reduction but
not necessarily achieving such reductions in identical ways or with identical risk
criteria in every case (see Deisler, 1984, for an example of harmonization in the
chemical safety field). The harmonization between chemical and radiation risks of
different types could occur by clearly and explicitly taking into account the differenc-
es in risk-reduction criteria or strategies between hazards that have natural sources
(rather than, or in addition to, anthropogenic sources) and those that have only
anthropogenic sources: For example, risk criteria for substances with no natural
sources (including radionuclides such as plutonium or americium) could be different
from those used for substances that have natural sources (including carcinogenic
inorganic substances and organic materials with significant natural sources).
Whatever the nature of harmonization between the radiation and chemical
paradigms, it will need to incorporate as well the differences among ambient
environmental and indoor and occupational exposures, and the distributions of risks
and benefits among exposed individuals and the sources of the exposure.
Clearly, the choice among these options - and others that may exist — is a
policy choice that transcends scientific analysis. The leadership of the Environ-
mental Protection Agency has the authority and the responsibility to make the
choice. We urge the choice to be articulated clearly so that the scientists who assess
the risks of radiation and chemicals can understand the basis for subsequent
decisions about risk reduction.
98
REFERENCES
Ames, B.N., and L.S. Gold, 1990. Too Many Rodent Carcinogens: Mitogenesis
Increases Mutagenesis, Science 249:970-971, .
Clay, D.R, 1991. Role of the Baseline Risk Assessment in Superfund Remedy Selec-
tion Decisions,- Environmental Protection Agency Memorandum, April 22, 1991, p. 1
Deisler, P.F. Jr., 1984. Reducing the Carcinogenic Risks in Industry, Marcel-
Dekker, pp. 135-158.
EPA, 1986. Environmental Protection Agency, Guidelines for Carcinogen Risk
Assessment, Fed. Reg. 51:33992-34003, September 24, 1986..
EPA, 1989. Environmental Protection Agency, Risk Assessment Guidance for .
Superfund, Vol. 1, Human Health Evaluation Manual (Part A), EPA/540/1-89/002,
pp. 8-6.
EPA, 1991a. Environmental Protection Agency, Proposed Revisions in EPA Esti-
mates of Radon, Risks and Associated Uncertainties.
EPA, 1991b. Environmental Protection Agency, National Primary Drinking Water
Regulations; Radionuclides; Proposed Rule, Fed. Reg. 56:33050-33127, July 18,
1991, pp. 33051.
ICRP, 1991. International Commission on Radiological Protection, Radiation
Protection: 1990 Recommendations of the International Commission on Radiological
Protection, ICRP Publication 60, Pergamon Press. ;
Kocher, DC, and F.O. Hoffman, 1991. Regulating Environmental Carcinogens:
Where Do We Draw the Line?, Env. Sci. Technol. 25:1986-1989.
NAS/NRC, 1990. National Research Council, Health Effects of Exposure to Low
Levels of Ionizing Radiation (BEIR V). Report of the Committee on the Biological
Effects of Ionizing Radiations, National Academy Press, pp. 172-173. .
NCRP, 1987. National Council on Radiation Protection and Measurements, Expo-
sure of the Population of the United States and Canada from Natural Background
Radiation, NCRP Report 94.
99
NCRP, 1989. National Council on Radiation Protection and Measurements, Com-
parative Carcinogenicity of Ionking Radiation and Chemicals, NCRP Report No. 96,
pp.2.
SAB, 1992a: Science Advisory Board, Radiation Advisory Committee, Idaho Radionu-
clide Study, EPA-SAB-RAC-LTR-92-004, January 21, 1992.
SAB, 1992b: Science Advisory Board, Radiation Advisory Committee, Reducing
Risks from Radon; Drinking Water Criteria Documents, EPA-SAB-RAC-COM-92-
003, January 29, 1992.
Rodricks, J.V., S.M. Brett, and G.C. Wrenn, 1987. Significant Risk Decisions in
Federal Regulatory Agencies, Reg. Toxicol. Pharmacol. 7:307-320, 1987, p. 308, 310-
313
Travis, C.O, et al., 1987. Cancer Risk Management, Env-Sci. Technol. 21:415420.
Whipple, C, 1989. Courts Speak on Risk issue, Forum Appi. Research Publ. Policy,
4:96-99.
100
Appendix 6: The Effect of Various Issues on the Recommended ODWO
Issue
Effect on
Resulting
ODWO (Bq/L)
(Uncertainty)
ODWO
Level of
(Reduction
Risk
Factor)
(Excess
Cancers
per
1,000,000
Exposed)
MOEE proposed ODWO
-
>340
7,000
Rationale Document
(MOEE* s
(Based on 1 year of exposure)
proposed Interim
ODWQ)
Lifelong Exposure
70
>5
100
(Based on a 70 year lifespan)
(ACES' s
recommended
Drinking Water
Objective)
Risk Reduction from 5 excess cancers
5
> 1
20
per million exposed to
(ACES' s
1 excess cancer per million exposed.
recommended five
year target)
RBE* 1 or >1;
1 -3
( 1
Natural
Dose Conversion Factors;
?
Background
Areas of Uncertainty;
(Ultimate goal)
Organically Bound Tritium (longer
biological half-life)
*RBE is the relative biological effectiveness of tritium (also see Glossary).
101
Appendix 7: 1991 Tritium Data from the Nuclear Surveillance Program
and Analysis of Tritium in Drinking Water
Source: Rationale I k> umenl foi th I >eveIopmeni ol an Interim « Ontario I >rinl ing
Watei Objective for Tritium. November, 1993. Standards Development
Branch, Ontario Ministry of the Environment and En I pp.
AIT! NDLX I .' : 1991 TRITIUM DATA - NUCLEAR SURVEILl^AN'CE PROGRAM
PLANT
Range (Bq/I) in Treated Water
AJAX WTP
< 9- 50
AMHERSTBURG WTP
< 8- 34
BOWMANVTLLE WTP
< 9-27
DEEP RIVER
< 8- 12
HARROW-COLCHESTER
< 8- 12
KINCARDINE PUC
< 8- 25
NEWCASTLE
< 8- 24
OSHAWA WTP
< 9-36
PETAWAWA
< 9 - 370
PEMBROKE
< 9 - 270
PICKERING
17 - 21
TORONTO
< 8 - 57
WARKWORTII
< 9
WHEATLLY WTP
< 9 - 1 1
WHITBY UTP
*.
VERNEIîR WTP
< 10
APPENDIX D : ANALYSIS OF TRITIUM IN DRINKING WATER
The analysis of tritium in drinking water is conducted by the Radiation Protection
Service Laboratory (RPSL) of the Ontario Ministry of Labour.
The procedure used for the determination of tritium in water begins with the distillation
of the samples. The middle fraction of the distillate is combined with a liquid
scintillation cocktail and counted in a Liquid Scintillation Counter. Normal reported
detection limits are approximately 7 Bq per litre.
Also see: Appendix E. 1, p. 25. of Rationale Document for the Development of an
Interim Ontario Drinking Water Objective for Tritium.
102
Mark Goldberg*
Chair of ACES
GlobalTox International
Consultants Inc.
& University of Guelph
Guelph
Ian Brindle
Analytical Chemistry
Brock University
St. Catharines
Cindy O'Brien*
Occupational Hygenist
City of Toronto
Toronto
Kim Perrotta
Occupational Health
& Safety
Labour Consultant
Toronto
Keith Winterhalder
Plant and Soil Ecology
Laurentian University
Sudbury
ACES Members
Beth Savan*
Vice Chair of ACES
Environmental Research and
Education
University of Toronto
Toronto
Terry Burrell
Environmental Economics
and Law
Toronto
Sally Paterson*
Environmental Chemodynamics
University of Toronto
Toronto
Catherina Spoel
Environmental Law
Miller Thomson
Toronto
Robert Boldt
Occupational Health and
Environment
Samia
Doug Cook
Occupational Health and
Environment
Taurscale Consultants Ltd.
Bridgenorth
David Pengelly
Air Pollution Epidemiology
McMaster University
Hamilton
Ralph Stanley*
Public Health Protection
Peel Regional Health
Department
Brampton
Denotes Member of Tritium Workgroup
ACES Staff
Carol Bennett
Technical Advisor
Carole Brown
Receptionist
Dianne Corrigan
Scientific and Technical
Coordinator (Acting)
Kathy Paidock
Administrative Assistant
Advisory Committee on Environmental Standards
Suite 401
40 St. Clair Ave. West
Toronto, Ontario
M4V 1M2
Phone: (416)314-9265
Fax: (416)314-9270
Ontario