Potential for Carcinogenicity from Exposures to VOCs and Metals Related to 9/11

^V JOHNS HOPKINS

ft* BLOOMBERG

™ W SCHOOL of PUBLIC HEALTH

Potential for Carcinogenicity from
Exposures to VOCs and Metals

Related to 9/11

Virginia M. Weaver, MD, MPH
Environmental Health Sciences

Key Concepts/Questions

Cancer risk related to dose (concentration x duration)

- Generally considered an outcome from chronic exposure

- What is the shortest exposure duration that results in
measurable increased risk for cancer?

• Atomic bomb survivors, despite exposure to one bomb, had
chronic exposure from internal radiation and persistent
radioactivity environmentally

- Steeper exposure rate may result in greater risk

- Exposure construct for cancer differs from that for pulmonary
outcomes

• Collapse versus burning pile/exhaust/persistent carcinogens
in dust

Example of Exposure Categorization for
Cancer (Lorber et al, 2007)

The data on PAHs sorbed to PM divided into three
groups:

- early group (from Day 12 to Day 50)

• major WTC fires, activity from diesel engine activity of GZ
power generation, demolition equipment (cranes, bulldozers),
and debris removal (trucks)

- middle group (from Day 51 to Day 100)

• sporadic fires, some scaled-back rescue activity, and truck
traffic

- late group (from Day 101 to Day 200)

• Fires officially out, most WTC demolition done, power
restored, and only truck traffic and background remained as
PAH sources

Key Concepts/Questions

Latency

- Cancer outcomes vary by time since exposure onset

- Traditional teaching

•4-6 years for radiation induced leukemias

• 15-20 for most solid tumors

• 35-40 for asbestos induced mesothelioma

Mixtures - limited data yet common exposure
scenario

WTC IARC VOCs with Human Cancer
Sites

Group 1

- Benzene - acute non-lymphocytic leukemia; limited evidence
that benzene causes acute lymphocytic leukemia, chronic
lymphocytic leukemia, and multiple myeloma in humans (Baan
etal. 2009)

• Supported by Vlaanderen et al meta-analysis EHP 2008

- 1, 3-butadiene - leukemia and non-Hodgkin lymphoma

- Formaldehyde - nasopharyngeal, leukemia (strong but not
sufficient); limited for sinonasal

- Vinyl chloride - angiosarcoma of the liver

2A: Benzyl Chloride, ethylene dibromide,
tetrachloroethylene, trichloroethylene

NIOSH 2012 WTC IARC NTP

Exposure Characteristics

Exposures present in combustion products
- burning pile and diesel exhaust

Not persistent in environment and do not accumulate
in body

• So exposures during active generation (fires, diesel)

Associated with short latency cancer (leukemia)

Limited VOC Monitoring (Lorber et al
2007)

Samples to characterize VOC emissions within smoldering
piles on GZ and on other work areas within and bordering GZ
to determine if the area was safe for entry by rescue workers
and firefighters

- When samples showed "extremely high concentrations of VOCs", entry
prohibited

Mainly 4 min "grab samples"

- comprise the bulk of all measurements for VOCs

4-minute grab samples exceeded screening benchmarks
outside of GZ but still within restricted zones for:

- 1,3-butadiene, chloromethane, ethylbenzene, toluene, and acetone

• limited number 24-hour samples taken from GZ perimeter; 1,3-
butadiene, ethylbenzene, and toluene ~ 1,000 times lower than 4
min samples

Benzene Monitoring (Lorber et al 2007)

4-minute grab samples exceeded screening benchmarks inside and
outside restricted zones

- Actual values not in this publication

24-hour samples within a factor of 10 of the grab samples

- suggests that the grab sample concentrations were closer to sustained
concentrations

Six of fourteen 24-hour samples were above the detection limit of
0.0007 ppm

- three at 0.0007 or 0.0008, and three at 0.002, 0.0025, and 0.005 ppm.

- ATSDR Intermediate (>14-364 days), MRL of 0.004 ppm (current appears
to be 0.006 ppm for noncancer health effects )

- historic average for New York City of about 0.0005 ppm

"data suggest that the exposures to benzene at levels that approach
the Intermediate MRL were not likely to have lasted longer than 45
days."

VOCs Monitorina Results

Monitoring of truck drivers (Geyh et al 2005)

- Highest personal sample = 9 ppb

Until mid Dec: "airborne particulate levels in lower
Manhattan continued to decline but rose intermittently at
night and when the air was still. Transient increases were
noted also when the pile was disturbed and fires flared.
Diesel exhaust became an important contaminant"
(Landrigan 2004)

"acrid cloud hung over lower Manhattan and areas of
Brooklyn until the fires were finally extinguished on 20
December." (Landrigan 2004)

VOCs Potential Implications

Workers on pile are potential risk group

Was dose enough to cause measurable increase in
cancer?

- Highest 24 hour sample = 5 ppb but OSHA benzene std =
1000 ppb; NIOSH REL = 100 ppb

• based on for 40 hours per week x 40 years

- Levels potentially higher than measured values but still for
limited time period

IARC Group 1 Metals with Major Human
Cancer Sites

Arsenic - urinary bladder, lung, skin, liver, and kidney
cancer

Beryllium - Lung cancer

Cadmium - Lung cancer; prostate with Cd chloride

Chromium - Lung and sinonasal cancer

Nickel - lung and nasal cancers

Inorganic lead - 2A

NIOSH 2012 WTC IARC NTP

Metals

Acknowledgement: Thank you to Susan Sidel
Disclaimer:

- WTC metal exposures complex

- my expertise is metals and kidney

Metals: Cahill Incinerator Hypothesis

"simultaneous presence of finely powdered (circa 5 pm)
and highly basic (pH 11 to 12) cement dust and high
levels of very fine (< 0.25 |jm) sulfuric acid fumes"

"unprecedented levels of several metals in the very fine
mode aerosols"

- "liberation of those metals that are both present in elevated
concentrations in the debris and have depressed volatility
temperatures caused by the presence of organic materials and
chlorine under anaerobic conditions."

- "Health concerns focus on the workers at the site, as plume
lofting protected most of New York City."

Cahill et al. Chap. 9 Very Fine Aerosols from the World Trade Center Collapse Piles: Anaerobic
Incineration? Urban Aerosols and Their Impacts: Lessons Learned from the World Trade Center
Tragedy

Metals: Cahill Incinerator Hypothesis

Very fine metals were routinely seen, but while most
were at low concentrations, some metals (V, Ni, Cu,
As, Se, Br, and Hg) occurred at unprecedented levels
in the very fine size range (Cahill, 2004)

"The concentrations of very fine silicon, sulfur, and
many metals, as well as coarse anthropogenic
metals, decreased markedly during October, probably
in association with the cooling of the collapse piles.
Values of very fine elements seen in May, 2002 at the
WTC site were only a few percent of October values."
(Cahill 2004)

Metals

"Calcium and sulfate are the most soluble
components in the dust, but many other elements are
also readily leached, including metals such as Al, Sb,
Mo, Cr, Cu, and Zn."

"interpret health effects resulting from the short-term
exposure to the initial dust cloud and the longer-term
exposure to dusts resuspended during cleanup."

Plumlee et al. Chap. 12 Inorganic Chemical Composition and Chemical Reactivity of Settled Dust
Generated by the World Trade Center Building Collapse. Urban Aerosols and Their Impacts: Lessons
Learned from the World Trade Center Tragedy

Metals

"The smaller particles, which can penetrate into the
deep lung and would have been generated by
burning materials, were probably not captured in
these samples (dust samples)." Samet 2007

"Airborne lead levels were elevated in the first days
after 11 September, but never highly." Landrigan,
2004

Lioy EHP 2002

Because of the large mass of material deposited
within rehabitable buildings throughout lower
Manhattan, surface loading could enhance potential
nondietary exposures [to lead]

Concentrations of arsenic and cadmium were
relatively low, but in the micrograms/gram (parts per
million) concentration range.

Metals: Lorber 2007

"Samples evaluated for total Cr at GZ and at sites
surrounding GZ never exceeded the NIOSH REL of 0.5
mg/m 3 or the OSHA PEL of 1 mg/m 3 for Cr metal and
insoluble salts, or the ATSDR Intermediate MRL of 1
|jg/m 3 for Cr VI particulates.

Ni samples evaluated at GZ and at sites surrounding GZ
never exceeded the NIOSH REL of 0.015 mg/m 3 or the
OSHA PEL of 1 mg/m 3 for Ni metal. The ATSDR
Intermediate MRL for Ni of 0.2 pg/m 3 was exceeded only
once, on November 10, 2001, by a measurement of 0.49
pg/m 3 . Overall, monitored levels were rarely above
background."

Metals Implications

Metals are persistent in environment

- ? Risk for toddlers from persistent metals in dust in
residential areas

Deposited in lungs

- ? Increased half-life from high initial load

- Some metals bioaccumulate (lead, cadmium)

- ?lnteraction with high pH

•Although "Alkalinity decreased with decreasing particle
size, and PM2.5 had a more nearly neutral pH (Lioy et
al. 2002; McGee et al. 2003)." Landrigan 2004