The wildfires that swept through California in 2003 appear to have caused wheezing and other respiratory problems in many children, even those without asthma, according to a new study referenced on Yahoo! News.

Asthmatic children suffered the most symptoms from the smoky air, but non-asthmatic children also experienced wheezing, coughing, sore throats, eye irritation, and colds during the October 2003 wildfires. Authors of the study (which appeared in the American Journal of Respiratory and Critical Care Medicine) say that the wildfires gave non-asthmatics an idea of what it was like to live with asthma.

The wildfires raised levels of air-polluting particulate matter 10 to 20 times. The smoke containted carbon monoxide and other toxic substances, and it was especially dangerous for people with asthma.

Children who avoided outdoor activities and wore masks were less likely to suffer health problems.

‘It is clear that reduction of exposure to wildfire smoke reduces the health problems,’ says Dr. Nino Kunzli, the study's lead author.