Goods Movement Conference: Public Health Implications for the Mid-Atlantic Region

University of PennsylvaniaHouston 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 phaseOxygen Carbon dioxideNitrogen Carbon monoxideWater vaporNitrogen Oxides (especially NO)Sulfur Compounds

(especially Sulfur Oxides)Volatile Organic CompoundsLow MW Hydrocarbons…

 Composition of Diesel Exhaust

• Gas phase components of toxicological significance

Aldehydes (formaldehyde, acetaldehyde, acrolein)

Benzene1,3-butadienenitrosaminespolycyclic 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

Health Effects Institute, 1995

Elemental Carbon (EC)

PAHs ...

UnburnedFuel

Dr. John Froines, Director, UCLA Southern California Particulate Center and Supersite

How small are these particles?

Human Hair(50-100 m diameter)

PM10

(10 m)PM2.5

(2.5 m)

Hair cross section (50-100 m)

PM0.1

(0.1 m)

• Nose and Throat Remove Particles > 10 m

• Trachea and Upper Bronchi remove Particles < 10 m and > 2.5 m

• Particles < 2.5 m and >0.1 m are deposited in Bronchioles and Alveoli

• Ultrafine particles (<0.1 m) reach all areas of lung and to some degree diffuse into body tissues

Where they go

Substances in Diesel Exhaust Listed by the California Air Resources Board as Toxic Air Contaminantsacetaldehyde cobalt compounds nickel

acrolein cresol isomers 4-nitrobiphenyl

aniline cyanide compounds phenol

antimony compounds dibutylphthalate phosphorus

arsenic dioxins and dibenzofurans POM, including PAHs

benzene ethyl benzene and their derivatives

beryllium compounds formaldehyde propionaldehyde

biphenyl hexane selenium compounds

bis[2-ethylhexyl]phthalate lead (inorganic) styrene

1,3-butadiene manganese compounds toluene

cadmium mercury compounds xylene isomers, mixtures

chlorine methanol o-xylenes

chlorobenzene methyl ethyl ketone m-xylenes

chromium compounds naphthalene 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 ParticulateENTIRE UNITED STATES 125,110 20 Largest Metropolitan AreasMetropolitan Area CancersLos Angeles 16,250New York 10,360Chicago 4,535Washington/Baltimore 3,750San Francisco 3,510Philadelphia 3,085Boston 2,900Detroit 2,810Dallas/Fort Worth 2,470

- continued...

Estimated Cancers fromDiesel Particulate 20 Largest Metropolitan Areas - continuedMetropolitan Area CancersHouston 2,270Atlanta 1,930Miami/Fort Lauderdale 1,880Seattle 1,765Phoenix 1,510Cleveland 1,500Minneapolis 1,460San Diego 1,430St. Louis 1,320Denver 1,220Pittsburgh 1,210

Cancer Risk Assessments of Diesel Exhaust

ORGANIZATION YEARCONCLUSION

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 YEAR CONCLUSION

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 Potentialof 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 EnvironmentalProtection Agency recognizes as reasonablyallowable (levels yielding a one-in-a-millionrisk):– 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 everyAmerican community is clean and healthy.

 We will breathe easier when people are free from the addictivegrip of cigarettes and the debilitating effects of lung disease. 

We will breathe easier when the air in our public spaces andworkplaces is clear of secondhand smoke.

We will breathe easier when children no longerbattle airborne poisons or fear an asthma attack. 

Until then, we are fighting for air.