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Breathing toxins

November 21, 2008 |  7:07 pm

The Los Angeles skyline is obscured by smoke from wildfires this month.

Anybody breathing in the Los Angeles Basin during last weekend's wildfires knows the air was bad. But it's worse than you think.

Researchers analyzing air samples taken during the October 2007 wildfires in Southern California found some nasty stuff in the smoke that blanketed the region.

It was full of tiny particles — 100,000 times smaller than the diameter of a human hair — that can penetrate into the lower lung and migrate into the bloodstream. Their complex chemical composition makes them slightly more toxic than pollutants in a freeway corridor — and they are spread over a much wider area.

The smoke particulates are adept at producing free radicals that can damage cells and lead to disease. Roughly half the matter sampled was organic carbon, which includes known carcinogens. Levels of metals such as copper emitted from burning buildings were also higher.

Staying behind closed windows in an old house without central air conditioning air won't help much, said Constantinos Sioutas, one of the authors of the study, which will be published in the journal Environmental Science and Technology.

Better to head to an enclosed mall or a building with recirculated air. "More aggressive measures to avoid smoke seem to deserve study, including distribution of masks and evacuation to air-conditioned environments," said Sioutas, the Fred Champion professor of civil and environmental engineering at USC.            

— Bettina Boxall

Photo: The Los Angeles skyline is obscured by smoke from wildfires this month. Credit: David McNew / Getty Images