Study Links ADHD to Air Pollution Exposure

Science draws a connection between exposure to pollution during pregnancy and unwanted cognitive and behavioral problems, like ADHD, in childhood.

Study Links ADHD with Air Pollution Exposure Iakov Filimonov/Shutterstock

While most pregnant women know intuitively that the air they breathe can affect the health of their unborn child, new research published in JAMA Psychiatry gives us proof that a polluted environment can mean an increased risk of ADHD symptoms, plus other cognitive and behavioral problems, in children.

A team working at the Institute for the Developing Mind at The Saban Research Institute of Children's Hospital Los Angeles conducted a small but powerful study that links prenatal exposure to PAHs (polycyclic aromatic hydrocarbons) with reduced white matter in the left hemisphere of the brain. This kind of erosion is associated with ADHD behavioral symptoms, aggression, and slower informational processing in IQ tests. (Previous findings draw a connection to developmental delays, diminished verbal IQ, anxiety, and depression.) Postnatal exposure was tied to further white matter deterioration and consequential difficulties with concentration and problem-solving.

The researchers have been looking at 620 New York City-based minority women and closely focused on 40 mothers and their children. The kids' brains were measured, some up until the age of 9, using MRIs, which revealed that more PAH exposure equated with more dramatic brain changes.

Car and truck emissions, oil and coal burning for heat, wildfires, hazardous waste sites, charred food, and tobacco smoke all contribute to environmental PAHs. So who's to blame?

"The onus needs to be on the polluters, which is neither the individual nor the government," says Jerome A. Paulson, MD, FAAP, Professor Emeritus of Pediatrics and Environmental & Occupational Health at George Washington University Schools of Medicine and Public Health and Chair of the AAP Council on Environmental Health. "However, realistically, businesses need incentives to reduce the production of pollutants; and, generally, those incentives come in the form of government regulations."

But without further laws and regulations in place, should parents be worried?

"This study, and others, show an association between exposure to an air pollutant and an adverse birth outcome. An association does not demonstrate cause and effect," Paulson says. So while this evidence of correlation doesn't imply causation, it's still reason enough for pregnant women and new mothers to limit exposure.

How to limit your exposure

"The take-home message from this study is not that women (or men or children) should go around with face masks," Paulson says. Those devices actually won't protect you from the PAHs we're talking about. Here's what Paulson and fellow study author, Frederica Perera, DrPH, PhD, Professor of Environmental Health Sciences at the Mailman School of Public Health Columbia University and director of the Columbia Center for Children's Environmental Health, do recommend:

-Check your local air quality agency and avoid outdoor activities on bad air days. Visit or download an air quality app—AIRNow, AirStatus, MyAirQuality, or State of the Air—to your smartphone.

-Avoid heavily trafficked areas as much as possible.

-Drive the lowest emission vehicle you can, to reduce air pollution in general.

-During warm weather, fill gas tanks in the evening to prevent gasoline vaporization.

-Limit the use of gasoline powered garden tools.

-Limit energy use in the home and office.

-Those who smoke should stop.

-Limit exposure to indoor sources of PAH such as secondhand smoke, incense, and candle burning.

-Use proper ventilation during cooking, and avoid eating charred foods.

-Be active in your community to try to limit air pollution on a local, regional, national and international level. Check out

Of course, following these recommendations doesn't guarantee that you're safe from adverse pregnancy outcomes, but they could help.