Goods Movement Conference: Public Health
Implications for the Mid-Atlantic Region
University of Pennsylvania
Houston Hall – Bodek Lounge
Philadelphia, Pennsylvania
Friday, September 23, 2011
Diesel Pollution
Cancer and Other Health Risks
Kevin M. Stewart
Director of Environmental Health
American Lung Association of the Mid-Atlantic
Outline
•
•
•
•
Diesel Exhaust Composition
Diesel Health Effects Overview
Diesel Emissions as a Carcinogen
Some Factors Associated with Goods Movement
Influencing Health Outcomes
• Conclusion
What is Diesel Exhaust?
Composition of Diesel Exhaust
• Complex mixture of thousands of
chemicals
• Gases and fine particles
• Over forty air contaminants recognized as
toxins, carcinogens, reproductive and
developmental hazards, endocrine disruptors
Composition of Diesel Exhaust
• Gas phase
Oxygen
Carbon dioxide
Nitrogen
Carbon monoxide
Water vapor
Nitrogen Oxides (especially NO)
Sulfur Compounds
(especially Sulfur Oxides)
Volatile Organic Compounds
Low MW Hydrocarbons
…
Composition of Diesel Exhaust
• Gas phase components of toxicological
significance
Aldehydes (formaldehyde, acetaldehyde,
acrolein)
Benzene
1,3-butadiene
nitrosamines
polycyclic aromatic hydrocarbons (PAHs)
nitro-PAHs
Composition of Diesel Exhaust
• Particulate phase
– Mostly elemental carbon (soot)
– About 20% to 40% adsorbed
organic compounds
– Also sulfate, nitrate, metals,
other trace elements
– The most toxicologically relevant adsorbed
compounds (less than 1% of PM by mass):
- PAHs
- Nitro-PAHs
- Oxidized PAH derivatives
– 92% of mass is in particles smaller than 1 micron
Diesel Exhaust Particles
Elemental Carbon (EC)
Unburned
Fuel
PAHs ...
Dr. John Froines, Director, UCLA Southern California Particulate Center and Supersite
Health Effects Institute, 1995
How small are these particles?
Hair cross section (50-100 mm)
Human Hair
(50-100 mm diameter)
PM0.1
PM10
PM2.5
(10 mm) (0.1 mm) (2.5 mm)
Where they go
• Nose and Throat
Remove Particles
> 10 mm
• Trachea and Upper
Bronchi remove
Particles < 10 mm and
> 2.5 mm
• Particles < 2.5 mm and
>0.1 mm are deposited
in Bronchioles and
Alveoli
• Ultrafine particles
(<0.1 mm) reach all
areas of lung and to
some degree diffuse
into body tissues
Substances in Diesel Exhaust Listed
by the California Air Resources Board
as Toxic Air Contaminants
acetaldehyde
acrolein
aniline
antimony compounds
arsenic
benzene
beryllium compounds
biphenyl
bis[2-ethylhexyl]phthalate
1,3-butadiene
cadmium
chlorine
chlorobenzene
chromium compounds
cobalt compounds
cresol isomers
cyanide compounds
dibutylphthalate
dioxins and dibenzofurans
ethyl benzene
formaldehyde
hexane
lead (inorganic)
manganese compounds
mercury compounds
methanol
methyl ethyl ketone
naphthalene
nickel
4-nitrobiphenyl
phenol
phosphorus
POM, including PAHs
and their derivatives
propionaldehyde
selenium compounds
styrene
toluene
xylene isomers, mixtures
o-xylenes
m-xylenes
p-xylenes
Diesel Health Effects Overview
Diesel Exhaust is a
“Quadruple Whammy” for
Public Health
•
•
•
•
Carcinogens
Toxins
Fine Particulate Matter
Nitrogen Oxides
Whammies 1 and 2
• Carcinogens
– Lung
– Bladder
• Toxins
–
–
–
–
–
–
–
Nervous
Endocrine
Reproductive
Immune
Developmental
Liver
Kidney
Whammy 3
• Fine Particulate Matter
– Premature death from respiratory and
cardiovascular causes, as well as stroke
– Increased hospitalization and emergency visits
for heart attacks, strokes, and acute respiratory
illnesses
– Exacerbation of asthma
• Increased frequency, severity, and duration of
episodes/attacks
• Increased symptom days and absenteeism
• Increased emergency visits and hospitalizations
Whammy 4
• Nitrogen Oxides
– Ozone precursor …
• Premature death
• Increased asthma attacks/episodes
• Increased need for medical treatment, emergency
visit, and hospitalization for persons with chronic
lung disease
– Increased susceptibility to respiratory
infections
– Decrease in lung function growth
Diesel Emissions as a Carcinogen
Estimated Cancers from
Diesel Particulate
State and Territorial Air Pollution Program
Administrators
and Association of Local Air Pollution Control
Officials
(STAPPA/ALAPCO, now NACAA)
Cancer Risk from Diesel Particulate: National and
Metropolitan Area Estimates for the United States,
March 15, 2000.
Estimated Cancers from
Diesel Particulate
ENTIRE UNITED STATES
125,110
20 Largest Metropolitan Areas
Metropolitan Area
Cancers
Los Angeles
16,250
New York
10,360
Chicago
4,535
Washington/Baltimore
3,750
San Francisco
3,510
Philadelphia
3,085
Boston
2,900
Detroit
2,810
Dallas/Fort Worth
2,470
- continued...
Estimated Cancers from
Diesel Particulate
20 Largest Metropolitan Areas - continued
Metropolitan Area
Cancers
Houston
2,270
Atlanta
1,930
Miami/Fort Lauderdale
1,880
Seattle
1,765
Phoenix
1,510
Cleveland
1,500
Minneapolis
1,460
San Diego
1,430
St. Louis
1,320
Denver
1,220
Pittsburgh
1,210
Cancer Risk Assessments of
Diesel Exhaust
ORGANIZATION
CONCLUSION
YEAR
National Institute for Occupational Safety and Health
1988
potential occupational carcinogen
International Agency for Research on Cancer (WHO)
1989
probable human carcinogen
State of California
1990
known to cause cancer
Health Effects Institute
1995
& World Health Organization
1996
consistency in showing weak association between
exposure to diesel exhaust and lung cancer
Cancer Risk Assessments of Diesel
Exhaust
ORGANIZATION
CONCLUSION
YEAR
California EPA (Staff Recommendation)
1998
“may cause an increase in the likelihood of cancer”
California Air Resources Board
1998
diesel particulate emissions are a toxic air contaminant
National Toxicology Program
1998
“diesel exhaust particulate is reasonably anticipated
to be a human carcinogen”
U.S. Environmental Protection Agency
2002
likely to be carcinogenic to humans by inhalation at
environmental levels of exposure
Cancer Risk Assessments of Diesel
Exhaust
• In a presentation to the Mid-Atlantic Clean Diesel
Collaborative in 2010, EPA’s Rich Cook noted:
– Strong desire among many stakeholders to develop
a cancer Unit Risk Estimate for diesel exhaust.
– Most recent request from National Environmental
Justice Advisory Committee (NEJAC)
– EPA Response: Data still inadequate to develop unit
risk estimate.
• Issue is [wide variation in] dose response relationships in
epidemiology studies
• However, EPA will continue to control emissions to the
maximum extent possible.
Cancer Risk Assessments of Diesel
Exhaust
• California Office of Environmental Health Hazard
Assessment has made estimates of risk:
– Estimated range of lung cancer risk (upper 95% confidence
interval) based on human epidemiological data is 1.3 x 10-4 to
2.4 x 10-3 per µg/m3.
– Overall, after considering the results of the meta-analysis of
human studies, as well as the detailed analysis of railroad
workers, the Scientific Review Panel concluded that 3 x 10-4
per µg/m3 is a reasonable estimate of unit risk expressed in
terms of diesel particulate.
Carcinogenic Potential
of Diesel Emissions
• Carcinogens in vapor phase
– Benzene
– Formaldehyde
– 1,3-butadiene
– Ethylene dibromide
• Adsorbed onto particles
– 3 PAHs (including BAP) classified as
probably carcinogenic to humans
– At least 16 hydrocarbons classified as
possibly carcinogenic to humans
• These do not account for all of the cancer risk
associated with diesel exhaust.
Carcinogenic Potential of
Diesel Emissions
• Meta-analysis by California Office of Environmental
Health Hazard Assessment on diesel exhaust and
lung cancer:
– Clear positive relationship between occupational
diesel exhaust and lung cancer
– Cigarette smoking removed as confounder
– Consistent with causal relationship
– Association with 40% increase in relative risk
Carcinogenic Potential of
Diesel Emissions
• Over thirty studies have investigated the exposure
of bus and truck drivers, railroad and shipyard
workers to diesel exhaust.
• A meta-analysis on diesel exhaust and bladder
cancer (January, 2001 by Boffetta and Silverman in
Epidemiology):
– Found an increased risk of between 18% and
76% among occupationally exposed individuals.
Carcinogenic Potential of
Diesel Emissions
• People are exposed to hundreds of times the
amount of carcinogens the Environmental
Protection Agency recognizes as reasonably
allowable (levels yielding a one-in-a-million
risk):
– In 1996 the national average lifetime cancer
risk from breathing outdoor hazardous
pollutants was 1 in 2,100.
– Mobile sources: 93% of this risk
– Diesel emissions: over 95% of the mobile
sources’ contribution (89% of the total)
Carcinogenic Potential of
Diesel Emissions
• In 2005, Clean Air Task Force estimated:
– Average lifetime nationwide cancer risk due to
diesel exhaust is over 350 in a million.
– Residents from more than two-thirds of all U.S.
counties face a cancer risk from diesel exhaust
greater than 100 deaths per million population.
– People living in eleven urban counties face
diesel cancer risks greater than 1,000 in a
million.
– The risk of lung cancer from diesel exhaust for
people living in urban areas is three times that
for those living in rural areas.
Some Factors Associated
with Goods Movement
Influencing Health Outcomes
Nature of Sources
•
•
•
•
Big
Old
Dirty
Inefficient
Nature of Fuels
• Finally, where
highway diesel
has needed to
be at 15 ppm,
other diesel fuel
has been at 500 ppm sulfur.
(Clean Diesel Fuel Alliance)
• Fuels used in shipping, where emissions have been
virtually unregulated, run from 1 – 5 percent sulfur.
Concentration of Activity
Proximity
(Prof. Andrea Hricko, Keck Sch. of Med. USC, 2011)
Proximity
“If we have
diesel sources,
the best thing
we can do is to
keep them 500
meters away
from people.”
(Mike Nazemi, SCAQMD, Presentation, Mira Loma, CA, 2002)
Proximity
PM2.5 comparison Newark, NJ
(NJEF and CWA, 2006)
Proximity
PM0.1 particle count comparison Newark, NJ
(NJEF and CWA, 2006)
Concentration of Population
(Population Density for Counties July 1, 2009)
Proximity as a Consequence
• Behavioral factors influenced by that highly
populous environment:
“Findings in published, peer-reviewed health
research estimate that, although we spend only
about six percent of our day commuting to and
from work, over half of our exposure to these
particles may occur during that travel time.”
- George D. Thurston, Sc.D., NYU Sch. of Med.
Populations at Risk
Delaware
Maryland
New Jersey
Pennsylvania
Total Population
873,092
5,633,597
8,682,661
12,448,279
Under 18
206,229
1,340,583
2,047,582
2,762,004
65 and Above
121,688
679,565
1,150,941
1,910,571
Pediatric Asthma
19,414
126,197
192,753
260,003
Adult Asthma
63,267
402,170
568,274
891,605
Chronic Bronchitis
29,411
187,490
292,135
432,231
Emphysema
11,836
71,392
115,440
180,491
Cardiovascular Disease
249,813
1,553,040
2,461,401
3,737,863
Diabetes
56,460
375,211
564,620
859,063
Poverty
87,978
448,789
740,070
1,454,240
Environmental Justice Concerns
• Racial and Ethnic
Disparities
• Socioeconomic
Disparities (Poverty)
• Disparities in Access to
& Quality of Medical Care
Concluding Remarks
Observation
PM2.5 levels in traffic, Austin, TX (CATF, 2007)
Cars only (MOPAC)
With trucks (I-35)
One Part of the Solution
Retrofitting with diesel particulate filters (CATF, 2007)
Before
After
We will breathe easier when the air in every
American community is clean and healthy.
We will breathe easier when people are free from the addictive
grip of cigarettes and the debilitating effects of lung disease.
We will breathe easier when the air in our public spaces and
workplaces is clear of secondhand smoke.
We will breathe easier when children no longer
battle airborne poisons or fear an asthma attack.
Until then, we are fighting for air.