Report (Southern CA Env Report Card): Time spent in traffic determines diesel exposure

“According to researchers from the University of California, Los Angeles, the amount of time Californians spend sitting in traffic is generally the largest factor in the amount of diesel exhaust particles they inhale. Black carbon, an important component of diesel particulate matter, was measured inside a car following such vehicles at a rate nearly 20 times higher than when the car followed a regular passenger car, according to UCLA environmental sciences professor Arthur Winer. The findings were included in UCLA’s seventh annual Southern California Environmental Report card, which grades the region in four different environmental categories each year. The report emphasized a shift in recent years in the study of pollution. Instead of focusing solely on data from stationary monitoring stations, researchers now hone in on “”microenvironments”” by measuring where people spend their time and how harmful pollutants reach them in each place they are. Using such techniques, UCLA scientists determined that one-third to one-half of the diesel particles an average Californian breathes every day comes in the 1 1/2 hours spent in the car. That accounted for the largest single factor in determining particulate exposure.”” Excerpted from the San Jose Mercury News. To read the full article, visit // peninsula/10024999.htm?template=contentModules/printstory.jsp. To read the press release from UCLA, visit //”””