Clean Air Task Force

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Problems of Diesel


photo of girl with inhaler

Unlike the industrial pollutants released from smokestacks, diesel engine exhaust is emitted at ground level, where Americans breathe it every day—whether we walk, ride bicycles, drive cars, take the subway, or commute via train, ferry, or transit bus.

Diesel exhaust is comprised of microscopic carbon soot particles that act to absorb metals and other toxic substances in the exhaust. When inhaled by humans, these tiny, toxic-laden particles cross the blood barrier from lungs into the bloodstream, delivering the toxics to internal organs and leading to inflammation and cardiovascular and respiratory diseases such as cancer, stroke, and heart attacks. In fact, particulate pollution from diesel shortens the lives of 21,000 people per year due to respiratory and cardiovascular disease, including about 3,000 from lung cancer. In addition, diesel takes its toll in cardiovascular disease with an estimated 27,000 heart attacks annually, and is responsible for approximately 400,000 asthma attacks a year. The nationwide diesel cancer risk is more than 200 times the one-in-one-million level that EPA considers acceptable. Diesel pollution also affects our nation’s productivity, with more than two million work days a year estimated lost due to diesel pollution health effects. CATF projectestimates that diesel fine particle pollution will account for approximately $139 billion in monetized damages or losses in 2010.

Visit the CATF map to view diesel health risks in your community.

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Neighborhoods near truck routes are routinely exposed to higher than normal levels of diesel exhaust.


black carbon particle cross-section graphic
Black carbon makes up the core of a diesel particle.

Black carbon, a component of diesel exhaust, is one of the largest contributing pollutants to global warming. Black carbon warms the atmosphere by absorbing sunlight and radiating heat into the air (like a blacktop road). Black carbon can also directly accelerate melting, by darkening snow and ice. As a global warming pollutant, black carbon is about 2,000 times more potent than the equivalent amount of CO2 over a 20-year period. The United States has the highest per-capita emissions of black carbon in the world. More than half of U.S. black carbon emissions come from diesel engines – 41% from on-road diesels and 16% from off-road diesels.