Overall, 17% of children in the United States are obese, but in inner-city neighborhoods, the rate of childhood obesity is as high as 25%.
Researchers at Columbia University’s Mailman School of Public Health have found that pregnant women in New York City exposed to higher concentrations of chemicals called polycyclic aromatic hydrocarbons, or PAHs, were more than twice as likely to have children who were obese by age 7 compared with women with lower levels of exposure.
PAHs, a common urban pollutant, are released into the air from the burning of coal, diesel, oil and gas, or other organic substances such as tobacco.
Results of the Columbia study are published online in the American Journal of Epidemiology.
“Obesity is a complex disease with multiple risk factors. It isn’t just the result of individual choices like diet and exercise,” says the study’s lead author Andrew G. Rundle, DrPH, a professor of epidemiology at Columbia’s Mailman School of Public Health. “For many people who don’t have the resources to buy healthy food or don’t have the time to exercise, prenatal exposure to air pollution may tip the scales, making them even more susceptible to obesity.”
Children of women exposed to high levels of PAHs during pregnancy were nearly twice as likely (1.79 times) to be obese at age 5, and more than twice as likely (2.26 times) to be obese at age 7, compared with children of mothers with lower levels of exposure, according to the Columbia research.
The 7-year-olds whose mothers were in the highest exposure group had, on average, 2.4 lbs. more fat mass than children of mothers with the least exposure, they observed.
“Not only was their body mass higher, but it was higher due to body fat rather than bone or muscle mass,” says Dr. Rundle.
Previous research at the Columbia Center for Children’s Environmental Health at Columbia’s Mailman School found that prenatal exposure to PAHs can negatively affect childhood IQs and is linked to anxiety, depression and attention problems in young children. PAHs also disrupt the body’s endocrine system and are known carcinogens.
Robin Whyatt, DrPH, the paper’s senior author, notes that the study is one of the first to present evidence that chemicals in the environmental can contribute to obesity in human beings.
Future research will focus on identifying other examples of these “obesogens” and ways to reduce them, says Dr. Whyatt, who is deputy director at CCCEH and professor of clinical environmental health sciences at the Mailman School.
Read Dr. Galland’s article Sick Building, Sick People
Am. J. Epidemiol. (2012) doi: 10.1093/aje/kwr455 First published online: April 13, 2012 “Association of Childhood Obesity With Maternal Exposure to Ambient Air Polycyclic Aromatic Hydrocarbons During Pregnancy,” Andrew Rundle et al, Department of Epidemiology, Mailman School of Public Health, Columbia University, 722 West 168th Street, Room 730, New York, NY 10032
Funding was provided by a grant from the National Institute of Environmental Health Sciences .