New research shows that a pregnant woman's exposure to pollution may impact her unborn child's developing brain. Health Reporter Erin Billups filed the following report.

The placenta isn't the perfect barrier scientists once thought. An ongoing study of more than 600 children living in Upper Manhattan details the damaging impact pollution can have on a child's developing brain.

"Since this was launched in 1998 the oldest children are now 16, 17," says Columbia University Center for Children's Environmental Health Director Frederica Perera.

Previous studies of the children have linked prenatal exposure to airborne hydrocarbons known as PAH to asthma, developmental delays and behavioral problems like ADHD.

Now researchers at Columbia University's Mailman School of Public Health have been able to actually document, with MRI's, the damage to the brain.

"It does raise concerns about these common combustion related pollutants that come from traffic, from oil and coal burning," says Perera.

Perera says their work discovered a reduction of white matter in the left hemisphere of the brain in kids with higher prenatal PAH exposures.

"They were associated with several of those cognitive and behavioral problems that we had observed," says Perera.

The pilot study published in JAMA Psychiatry involved just 40 of the 600 children being followed. Perera says an analysis of the larger group is now underway.

They're comparing the imaging with air samples taken from mothers who wore backpacks with air monitors for a period of 40 hours during their pregnancy.

Perera says the city's air quality is slowly improving but not fast enough. She says as city officials focus in on early childhood development the environment should be part of the discussion, especially for those in low income areas - who tend to be at highest exposure - with the least resources to fight it.

"In addition to all the other things we need to do to nurture young children and make them ready for school and good learners we really must start early on to prevent toxic environmental exposures," says Perera.

Perera says an antioxidant rich diet of vegetables and fruits can help buffer the damage caused by pollution.

For more information and tips, visit ccceh.org.