How Pollution Could Affect Your Baby's Development

Prenatal air pollution exposure tied to reduced brain white matter, which may affect cognition and behavior

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Pollution exposure is a well-known factor in breathing problems in children, but new evidence suggests it may also contribute to other health issues.

A small new study found that prenatal exposure to a type of pollution called polycyclic aromatic hydrocarbons (PAHs) may later contribute to reduced white matter in children's brains, which may be behind slowed thinking ability and behavioral problems like attention deficit hyperactivity disorder (ADHD).

Lead study author Bradley S. Peterson, MD, of Children’s Hospital Los Angeles, and colleagues wrote that the good news is "that every unit reduction in exposure to PAHs during gestation and early postnatal life should yield a proportionate reduction in white matter disturbance and its associated cognitive and behavioral effects. If confirmed, our findings have important public health implications given the ubiquity of PAHs in air pollutants among the general population."

Andre F. Hall, MD, a board-certified OB-GYN at Birth and Women's Care in Fayetteville, NC, told dailyRx News that "one can extrapolate the recommendations that are made for other environmental conditions to air pollution. Specifically, it is recommended that pregnant women avoid situations in which they will be exposed to fumes of items such as paint for example."

Dr. Hall added, "Any breathing condition or circumstance that might decrease the oxygen saturation of the blood that the unborn child has access to will potentially have an effect on development. The extent of this impairment however is difficult to quantify and will vary from individual to individual."

Vehicle exhaust, smoking and burning coal are common outdoor sources of PAHs. Indoor activities, such as cooking and using space heaters, can also produce PAHs.

Past research has found that PAHs may affect unborn babies' brains in the womb. To test this theory, Dr. Peterson and team looked at 40 Hispanic and black children living in urban areas. The study began when these children were still in the womb and continued until they were 7 to 9 years old.

The children's mothers were monitored for PAH exposure and answered surveys. When the children were between 7 and 9 years old, Dr. Peterson and team looked at images of their brains and gave them intelligence tests.

Children who had been exposed to more PAHs in the womb were more likely to have reduced white matter on the left side of their brains than kids who hadn't been as exposed, Dr. Peterson and team found. Reduced white matter was tied to slower thinking during the intelligence tests and behavioral problems like ADHD. ADHD is a condition common to children that is marked by trouble paying attention, impulsiveness and hyperactivity.

Among the limitations of this research were the small sample size and the fact that Dr. Peterson and colleagues monitored for PAH exposure during the third trimester of the women's pregnancies. Babies may be more vulnerable to PAHs earlier in pregnancy.

This study was published March 25 in JAMA Psychiatry.

Grants from the National Institute of Environmental Health Sciences, the US Environmental Protection Agency and the National Institute of Mental Health funded this research. Dr. Peterson and team disclosed no conflicts of interest.

Review Date: 
March 27, 2015
Last Updated:
March 31, 2015