Overall, 17% of children in the United States are obese, and in inner-city neighborhoods, the prevalence is as high as 25%. While poor diets and physical inactivity are the main culprits, there is new evidence that air pollution can play a role.
A study by Columbia University's Mailman School of Public Health finds that pregnant women in New York City exposed to higher concentrations of chemicals called polycyclic aromatic hydrocarbons, or PAH, were more than twice as likely to have children who were obese by age 7 compared with women with lower levels of exposure. PAH, 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 are published 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, Dr. P.H., 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."
Researchers recruited 702 non-smoking pregnant women through prenatal clinics at NewYork-Presbyterian Hospital and Harlem Hospital. The women were 18-35 years old, identified themselves as either African-American or Dominican, and lived in areas in Northern Manhattan or the South Bronx that are predominantly low income. Over the course of two days during their third trimester, they wore a small backpack equipped to continually sample the surrounding air; at night they placed it near their bed.
Children of women exposed to high levels of PAH 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,
|Contact: Timothy S. Paul|
Columbia University's Mailman School of Public Health