The small particles spewed into the air by wildfires can wreak havoc on a person's health on a grand scale.
What residents of California and other areas under siege can do to reduce their risk.
In explaining how the sustained drought in California and other parts of the West might be affecting people living through it, experts point not only to parched ground but to the hazy skies.
Specifically, the spikes in so-called particulate matter, or particle pollution, that obscures views, resulting from blazes sparked in the prolonged dry heat. "I think the clearest link between drought conditions and respiratory health is mediated by increased frequency and severity of wildland fires," says Dr. Paul Blanc, a professor of medicine and endowed chair in occupational and environmental medicine at the University of California–San Francisco.