Early Exposure to Chemicals May Boost Risk of Asthma
Scientists trying to unravel why childhood asthma has reached epidemic proportions have reported that a variety of chemical exposures during infancy -- including pesticides and wood smoke -- can substantially increase a child's risk of developing the disease.
Studying nearly 700 children in 12 communities in the Los Angeles region, a team at USC found that children exposed to household pesticides in their first year of life were more than twice as likely to develop asthma than those never exposed. Infants exposed to wood smoke, household cockroaches and farm animals also suffered considerably more asthma.
Asthma is the most prevalent disease affecting American children, causing more hospital stays and missed school days than any other chronic childhood illness. While medical officials today have a good understanding of how to treat breathing problems in asthmatics, they have struggled for years to figure out what makes so many children vulnerable to the disease.
About 20 million people in the United States suffer from asthma, including more than 3.5 million children under the age of 15. Nearly twice as many preschoolers and school-age children had asthma in 1999 than in 1980, according to a Centers for Disease Control and Prevention report. About 5,000 people die from asthma attacks in the country every year.
The USC study suggested that there was no single cause, but an array of factors in children's lives responsible for asthma. It also indicated that contaminants -- indoors and outdoors -- have particularly potent effects on infants, so that a baby's experiences might determine how healthy he or she is for the rest of his or her life.
"The main message is that early in life, the first year of life may be a very, very important time for respiratory health, and that children may be uniquely susceptible then," said Dr. Frank D. Gilliland, a professor of preventive medicine at USC's Keck School of Medicine. Gilliland was the lead author of the report, which was published in the online version of the scientific journal Environmental Health Perspectives.
The study, which was one of the largest worldwide to examine factors contributing to childhood asthma, confirmed many of the findings of other research. Of 691 children between the ages of 8 and 18 recruited for the study, 279 had asthma and 412 did not.
