Air Pollution Link to Childhood Obesity

PAH air pollutant exposure to pregnant women may contribute to childhood obesity rates

(RxWiki News) It may not just be chicken nuggets and french fries adding too much weight to children's waistlines. The very air pregnant women breathe might play a small role too.

A recent study has revealed that a mother's exposure to air pollution while she's pregnant might have a connection to childhood obesity.

"Avoid air pollution as much as possible while pregnant."

Lead author Andrew Rundle, DrPH, an epidemiology professor at Columbia University's Mailman School of Public Health, and colleagues conducted a study with 702 non-smoking pregnant women at New York-Presbyterian Hospital and Harlem Hospital.

The women, who ranged from 18 to 35 years old, were either African-American or Dominican and lived in mostly low-income areas of the South Bronx or Northern Manhattan.

For two days during their third trimester, each woman wore a small backpack that regularly sampled the air around the woman. Both nights, the women kept the backpack by their beds.

The researchers found a link between the rates of obesity among the women's children and a specific type of chemical in the air called polycyclic aromatic hydrocarbons, or PAH. These pollutants enter the air from burning coal, diesel, oil, gas and other organic materials like tobacco.

The researchers found that women with the highest exposures to PAH while pregnant had children who were 1.8 times as likely to be obese when they were five years old compared to the mothers who had the lowest levels of exposure.

That risk grew to more than twice as likely when the children were 7 years old. On average, the 7-year old children of mothers with high exposures to PAH had 2.4 more pounds of body fat than the mothers with the lowest levels of PAH exposure.

These associations remained even when the researchers made adjustments to account for the women's socioeconomic status and household income.

The connection to obesity also did not go away when researchers took into account exposure to cigarette smoke in the home and how close the families lived to streets with high levels of traffic.

Previous research with animals and tissues in the lab have found similar associations between PAH and obesity, and past research has shown an association between prenatal PAH exposure and mental disorders like anxiety, depression and attention problems in kids. PAH are also carcinogens, which means they can contribute to causing cancer.

The authors recommend reducing PAH exposure for women by getting rid of diesel buses and ensuring that all oil furnaces are adjusted to burn clear fuel. Both these initiatives are already making an impact in New York, the authors write.

The study appeared online April 13 in the American Journal of Epidemiology. The research was funded by a grant from the National Institute of Environmental Health Sciences. The authors declared no conflicts of interest.

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Review Date: 
April 17, 2012