Children’s Exposure to Air Pollutants Most Influenced by Air in the Home

Newswise — Inner-city Minneapolis children are exposed to volatile organic compounds (VOCs) in greater amounts in the home than outside or at school, according to a study published today in the October issue of the peer-reviewed journal Environmental Health Perspectives (EHP). (In honor of Children's Health Month, the October issue of EHP is focused specifically on children's environmental health.) The study of 153 elementary school children found that air samples obtained outdoors and in school contained fewer measured hazardous air pollutants than the air in the children's personal breathing zone, which in turn contained fewer pollutants than the air in the children's primary residence.

The study also found variability in the types of exposure between racial/ethnic groups in the study. For example, time-diary and biomarker data indicate that African-American children in the study had higher tobacco exposures than did other racial/ethnic groups. Somali children, on the other hand, had significantly lower exposure to compounds associated with vehicle exhaust, consistent with the fact that these children reported less time spent in transit.

Common sources of indoor pollutants include tobacco smoke, household cleaners, room deodorizers, toilet bowl blocks, moth cakes, attached garages, and fragrances. Increased ventilation in the home was associated with reduced concentrations of some pollutants with indoor sources.

The children in the study were exposed to relatively low levels of air pollutants outdoors, as compared to children in other U.S. metropolitan areas.

"The outdoors VOC levels measured in Minneapolis for this study are relatively low compared with those in other large metropolitan areas in the United States," the study authors write. "The Twin Cities metropolitan area is downwind of rural areas in the United States and Canada that have low VOC emissions, have relatively infrequent atmospheric inversions, and have no physical barriers that trap pollutants."

The research is consistent with earlier studies that have found that VOCs are typically higher indoors than outdoors.

"A lot of people think about 'air pollution' as something they largely can't control," said Dr. Jim Burkhart, science editor for EHP. "This study, however, reminds us that actions we take in our own homes can have a major influence, positive or negative, on the air we breathe."

The lead author of the study was John Adgate of the School of Public Health at the University of Minnesota. Other authors were Timothy R. Church, Andrew D. Ryan, Gurumurthy Ramachandran, Ann L. Fredrickson, Thomas H. Stock, Maria T. Morandi, and Ken Sexton. The article is available free of charge at http://ehp.niehs.nih.gov/docs/2004/7107/abstract.html.

EHP is published by the National Institute of Environmental Health Sciences, part of the U.S. Department of Health and Human Services. EHP became an Open Access journal in January 2004. More information is available online at http://www.ehponline.org/.