Environment May Be Culprit in Childhood Asthma

TUESDAY, May 20, 2003 (HealthDayNews) -- Children exposed to certain chemicals, pollutants and irritants such as cockroaches, dust and farm crops during their first year of life may face a greater risk of developing asthma.

Weed killers, pesticides, fuel oil, soot, exhaust and farm crops, cockroaches, dust and animals all seemed to be linked to early asthma in children, a study from researchers at the Keck School of Medicine, University of Southern California, found.

Babies who first attended day care before they were 4 months old were also more likely to be diagnosed with asthma.

The study was presented May 20 at the annual international conference of the American Thoracic Society.

The researchers looked at 338 children diagnosed with asthma before they were 5 years old. They were compared to 570 asthma-free children of the same age who lived in the same communities.

The risk of developing asthma before age 5 was:

• More than four times greater for children exposed to herbicides before age 1.
• Nearly two-and-a-half times greater for children exposed to pesticides before age 1.
• Also nearly two-and-a-half times greater for children who attended day care before 4 months of age.
• More than two times greater for children exposed to cockroaches in the home before age 1.
• Nearly two times greater for children exposed to dust, animals or farm crops before age 1.
• More than 50 percent greater for children exposed to wood or oil smoke, soot or exhaust anytime between birth and the age of 5.

This study didn't look at the specific reasons why these exposures increased the risk of asthma in children.

"The first year of life seems uniquely important in terms of susceptibility to environmental triggers of asthma," study author Dr. Frank G. Gilliland, Keck professor of preventive medicine, says in a news release.

"The first year of life is a critical time period of lung development -- both for immunity and airway structure. Others have shown that certain early life exposures are important for asthma development," Gilliland says.

More information

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