LOS ANGELES DRIVERS AT RISK: A recent study by researchers at the University of Southern California (USC) and the California Air Resources Board found that up to half of Los Angeles residents' total exposure to dangerous air pollutants occurs while driving. About 33 percent to 45 percent of a Los Angeles driver's exposure to diesel and ultrafine particles (UFP) occur during their average 1.5 hours spent on the road.

Researchers say if you are an otherwise healthy individual who doesn't smoke, driving can be the unhealthiest part of your day. To reduce your exposure to UFPs, experts recommend driving with your windows closed while setting your air to re-circulate. (Source: Atmospheric Environment, 2008;42;207-219)

DIESEL EXHAUST INCREASES HEART ATTACK AND STROKE RISK: Another study by researchers in the United Kingdom and Sweden found diesel exhaust emitted from vehicles can increase your chance of heart attack and stroke by increasing clot formation and blood platelet activity. Blood clotting can lead to a blocked vessel, resulting in heart attack or stroke, researchers say. The study included 20 healthy men ranging from age 21 to 44. They were exposed either to filtered air or to a level of diluted diesel exhaust comparable to standing on a busy street. At two and six hours after exposure, a sample of each subject's blood was taken to measure clot formation, coagulation, platelet activation and inflammatory markers. Clot formation increased by 19.1 percent to 24.2 percent. Platelet activation also increased.

According to the Clean Air Task Force, over 13 million diesel vehicles drive on America's roads every day. Both busy and rural areas are polluted with diesel exhaust. In 2007, the U.S. Environmental Protection Agency (EPA) enacted regulations on the amount of emissions a diesel vehicle can give off. This rule, however, only applies to new vehicles -- the lifespan of the average vehicle is 30 years.

CLEANING THE AIR TO SAVE LIVES: Abt Associates, a consulting firm used by the EPA and other agencies to assess air quality, conducted a test on diesel exhaust for the Clean Air Task Force. Their findings are startling:

•Each year, fine particle pollution from diesel vehicles shortens the lives of nearly 21,000 people. This includes almost 3,000 early deaths due to lung cancer.

•If diesel fine particle emissions are reduced by 50 percent by 2010, 75 percent by 2015, and 85 percent by 2020, almost 100,000 lives could be saved between now and 2030.

•In the United States, diesel exhaust results in a cancer risk 7.5-times higher than the combined total cancer risk from all other air toxics.

•The risk of lung cancer from diesel exhaust for people living in urban areas is three-times that for those living in rural areas.