Diesel exhaust is one of the nation’s most pervasive sources of toxic air pollution. America’s 11 million diesels—buses, trucks, trains, ships, and construction equipment—emit pollutants that lead to 21,000 premature deaths each year and create a cancer risk that is seven times greater than the combined risk of all 181 other air toxics tracked by the EPA. Scientific studies link pollutants in diesel exhaust to a myriad of public health effects, including asthma attacks, heart attacks, stroke, cancer, and premature death.

http://www.catf.us/diesel/

n Environmental Protection Agency tests measuring how much air pollution a particular make and model vehicle produces, hybrid gasoline-based vehicles scored much higher than clean diesel vehicles. In recent years, Honda Civic hybrid vehicles have scored an average of 9, while diesel Jetta cars have averaged scores of between 5 and 6. For the purpose of these tests, 1 is the lowest score and 10 is the highest. Higher scores are awarded to vehicles that cause less air pollution.

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Although modern clean diesel is much better than the diesel fuel that was created and formulated in past years, exhaust from diesel engines can still cause serious illness. Breathing in even relatively small amounts of diesel exhaust can cause serious illness--especially in children, the elderly or the chronically ill. Even very short term exposure can cause existing allergies to worsen or cause symptoms of asthma or bronchitis.

http://www.carsdirect.com/car-buying/how-clean-are-diesel-cars-5-facts-based-on-pollution