Air Pollution Affects Childhood Obesity Risk

Air pollution should be considered, as poor diet and inactivity, when examining risk factors for childhood obesity, a new study of the effects of prenatal air pollution exposure suggests. 

Higher levels of exposure to polycyclic aromatic hydrocarbons (PAH)—pollutants caused by the burning of coal, diesel, oil, gas, and even tobacco—were associated with a child’s risk of obesity being twice that of an unexposed child by age 7.

"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," said Andrew Rundle, DPH of Columbia's Mailman School of Public Health.

Researchers recruited 702 pregnant women, aged 18 to 35 years, living in low-income areas of Northern Manhattan and the South Bronx, and equipped them with small air-testing backpacks to be worn during the day and set at bedside during the night. 

The 7-year-old children of women with high PAH exposure during pregnancy were 2.26 times more likely to be obese than children with low prenatal exposure.  The children in the group with the highest PAH exposure had a 1.93-unit higher percentage of body fat than their low-exposure counterparts. 

"Not only was their body mass higher, but it was higher due to body fat rather than bone or muscle mass," said Rundle.

These findings match the results of animal studies which showed that exposure to PAH causes gains in fat mass and prevents normal lipolysis.  

-Michael Potts