Exposure to Common Pollutant in Womb Might Lower IQ

July 21 -- MONDAY, July 20 (HealthDay News) -- Fetal exposure to high levels of a common airborne pollutant compound seems to threaten the intellectual development of children, a new study suggests.

The finding is based on the experience of black and Dominican-American families living in the New York City area. Specifically, it indicates that high prenatal exposure to these compounds -- automobile exhaust is one example -- translates into lower IQ scores by the time a child reaches the age of 5 years.

This linkage builds on prior research, which has suggested that exposure to these pollutants, known as polycyclic aromatic hydrocarbons (PAHs), while still in the womb can provoke developmental changes that damage lung health and boost the risk for developing childhood asthma.

"As a reference, most people know that lead exposure is harmful to children, and the effects we saw in terms of the association between PAH exposure and decreased IQ scores are comparable with low-level lead exposure, which is of concern because IQ level is a known predictor of a child's future academic performance," explained study author Frederica P. Perera, a professor in the department of environmental health sciences with the Mailman School of Public Health at Columbia University in New York City.

"And here we're talking about extremely common urban pollutants, found all across the U.S. and the world," Perera added. "Traffic emissions from diesel and gasoline vehicles -- like buses, trucks and cars -- are a major source of these pollutants, as is fuel-burning coal. So, certainly the exposure is widespread and not confined to any one population or area, and we have no reason to think that the effects that we see in our study will be any different for other ethnicities or locations."

Perera -- who also serves as director of the Columbia Center for Children's Environmental Health -- reports the findings online July 20 and in the August print issue of Pediatrics.