Can Busy Residential Streets Be As Toxic As Freeways?

Students at a Roseville middle school near busy, 6-lane Watt Avenue "are breathing higher levels of toxic particles than people immediately downwind of the Roseville train yard, the single largest generator of such pollution in the Sacramento area, according to an air pollution study scheduled to be released today (Dec.13).

"It shocked us all," said Thomas Cahill, a University of California, Davis, atmospheric physicist who led the study."

"Those findings spurred Cahill to look deeper. How could particle pollution that is normally associated with diesel soot be just as high along residential Watt as a freeway, with all its soot spewing trucks and buses? The most likely answer, the scientists concluded, was that the particles near the Arden school came mostly from run-down cars burning engine oil.

"A small fraction of cars dominates the automotive pollution," Cahill said. "That's a small fraction of cars putting out very toxic stuff."

Smoke from burned motor oil contains benzo-a-pyrene, the most prevalent cancer-causing air pollutant in California, Cahill said.

"Just because people may live along residential streets instead of freeways doesn't mean that they're safe from the harmful effects of car exhaust particulates, " Cahill said.