THE BRONX - Researchers at the Columbia Center for Children's Environmental Health in Chicago say kids exposed to air pollution before birth have lower IQs than other students.

The study focused on 249 expecting mothers from the Bronx and parts of Manhattan and measured the pollutants they were exposed to. Then, the researchers checked back with the families five years later and found that the children had IQs about four or five points lower than their peers who were exposed to fewer pollutants as fetuses.

A University of Chicago pediatrician says the study shows pregnant women don't have to live next door to obvious polluted areas to expose their babies to smog and other damaging elements.

AP wires contributed to this article.