Study: Air Pollution May Contribute to Obesity

Science has long known that air pollution from cigarette smoke and vehicle exhaust is linked to poor health outcomes, like heart disease and asthma. But recent study findings suggest exposure to air pollution may be contributing to obesity, too.

A study published last week in the peer-reviewed journal Environmental Health Perspectives followed more than 3,

300 children in California from ages 10 to 18, and measured their Body Mass Index, or BMI. They also recorded whether the children had been exposed to smoke in utero, were living in the same house as someone who smoked indoors, and the proximity of their home to a major roadway.

The study’s authors controlled for sex, the child’s initial BMI, physical activity level, parental education and income, the poverty rate in the community and several other factors. Even so, the study found that children who both were exposed to secondhand smoke at home and lived the closest to sources of vehicle pollution had a BMI of 2 kg/m2 higher than kids with neither exposure.
Further research is warranted to determine if our findings can be replicated in other populations and to assess both the potential contribution of combustion sources to the epidemic of obesity and the potential impact of interventions to reduce exposure. In utero and [secondhand smoke] exposure, as well as regional ambient [particulate matter] exposure, have been decreasing in California over the past several decades during which the obesity epidemic has developed (Al-Delaimy et al. 2010), and so these exposures by themselves are unlikely to have contributed to the epidemic. However, these trends in regional air pollutants have limited relevance to the potential role of [near road pollution], which is a different pollutant mixture. Vehicle miles traveled, exposure to some components of the [near road pollution] mixture, and near roadway residential development have increased during this period (Geller et al. 2005)… Thus, the potential for [near road pollution] to be among several factors contributing to the epidemic of obesity merits further investigation.
This is just one study in a sea of scientific research, but it’s interesting for a state like Kentucky, where more than 30 percent of its residents are classified as obese. And in Louisville, a city that’s struggled with air pollution for several reasons (meteorological and because of pollution sources), it’s particularly salient. Science is starting to suggest that high BMI and obesity isn’t always due to high caloric intake and minimal physical activity—and that maybe to address this particular health crisis, cleaning the air might help.