Maybe so, and worse, it could lead to heart disease. A new study of seniors living in Massachusetts suggests that black carbon, a component of traffic-generated air pollution, influences levels of leptin. High levels of this hormone are associated with obesity, diabetes and heart disease.
A team of researchers from Brown University measured blood levels of leptin in 765 seniors living in Boston and found that levels of the hormone were 27 percent higher among those with the most exposure to black carbon. These individuals also had lower incomes and higher rates of high blood pressure and diabetes than others in the study. The research team didn't establish where the pollution was generated, reporting that the proximity of the nearest major highway was not apparently related to leptin levels. Rather, they suggested that black carbon exposure probably reflects overall pollution from traffic on a wider range of roads in the immediate vicinity of the participants' homes. The study doesn't prove that black carbon exposure increases leptin levels, but the researchers suggested that their findings may help explain increases in cardiovascular disease associated with air pollution.