Jackson Free Press

This story appeared on Environmental Health News.

Exposure to traffic-related air pollution was associated with decreased attention skills in a group of Boston-area boys studied by researchers.

The study is the first to link exposure to black carbon to attention difficulties in low-income, urban children and to report differences between the genders.

The researchers at Icahn School of Medicine at Mount Sinai estimated how much black carbon 174 children were exposed to over their life and had them take an attention test when they were between the ages of 7 and 14. They found an association between black carbon exposure and test errors and overall reaction time for boys. There was no statistically significant effect on girls.

The findings "suggest that boys may be more susceptible to effects of traffic-related air pollution on attention, at least for some attention indicators," the researchers said in their study, which was published online in Environmental Health Perspectives.

Most black carbon emissions are from vehicles, and diesel engines are the primary culprit, according to the Environmental Protection Agency. Previous research has shown that ultra-fine particles of pollution can enter the brain.

The researchers broke the children into four groups based on estimates of their black carbon exposure. The strongest link to the attention problems was in the middle groups, while the group with the highest exposures had the weakest associations. The researchers did not know the reason, although they said it could be because the middle groups had lower IQs and lived in areas with more community violence than the highly exposed kids. "Socially enriched environments may protect children from neurotoxicants," they wrote.

In their calculations of the risk, the researchers tried to take into account various factors, including the children's social stress and blood lead level, and their mothers' education. Fifty-six percent of the children were Hispanic and 42 percent were non-Hispanic whites.

The study estimated the black carbon exposure for the kids based on modeling of emissions from measurements taken at monitoring stations near their residences. Hispanics and blacks were more likely to live in areas with higher emissions.

Other health studies have found associations between air pollution and reduced IQs and some learning, attention and memory difficulties in children. A 2012 Columbia University study found an association between air pollution exposure and anxiety and attention problems in 6- and 7- year- old New York City children. And a 2011 Environmental Health Canada study linked air pollution exposure and attention deficit disorder (ADHD) prevalence in children aged 9 to 17 years.

The Mount Sinai study is the first to find a difference between boys and girls when investigating possible effects from air pollution. According to the researchers, understanding gender differences when looking at environmental chemicals has become increasingly important. For example, an association between pre-natal smoking and ADHD among children was stronger in girls in a 2006 analysis by University of Wisconsin, Milwaukee, researchers. In addition, a 2012 Boston University study of organochlorines and children's attention only found an association among boys.