A new study found that exposing pregnant women to pollution can have a major affect on the IQ levels of their children.
The five-year study which followed the development of 249 children living in the densely populated areas of Harlem and the Bronx in New York showed that exposure to environmental pollutants known as polycyclic aromatic hydrocarbons (PAHs) had an adverse affect on intelligence quotient.
PAHs are toxic pollutants which result from burning coal, diesel or gas.
The study by the Columbia Center for Children's Environmental Health and financed by the National Institutes of Health found those children exposed to the highest levels of pollutants had an IQ some 4.31 to 4.67 points lower than other non-exposed children.
"These findings are of concern because these decreases in IQ could be educationally meaningful in terms of school performance," said Frederica Perera, the study's lead author and director of the Columbia Center.
She said the effects of these pollutants on IQ were similar to the findings of the damage caused by low-level exposure to lead.
"This finding is of concern because IQ is an important predictor of future academic performance, and PAHs are widespread in urban environments and throughout the world," she said.
"Fortunately, airborne PAH concentrations can be reduced through currently available controls, alternative energy sources and policy interventions," she added.