The study focuses on polycyclic aromatic hydrocarbons (PAHs), toxic pollutants resulting from vehicle emissions, coal burning, and smoking, Xinhua agency reported.
After PAHs cross the placenta, they affect the brain on an unborn child, and experiments showed prenatal exposure leads to impaired behavior and learning, according to researchers from Children’s Hospital in Los Angeles (CHLA) and Columbia University.
Scientists conducted an imaging study that included 40 minority urban school-aged children whose mothers were either Latin or African American women in New York City. The goal of the study was to examine the effects of PAHs exposure on brain structure.
The participating children were followed from birth until seven to nine years of age, while their mothers filled out prenatal PAH monitoring questionnaires.
“Our findings suggest that PAH are contributors to ADHD and other behavioural problems due to the pollutants’ disruptive effects on early brain development,” lead author Bradley Peterson, director of the Institute for the Developing Mind at the CHLA, said in a statement.
Researchers found a strong relationship between increased prenatal PAH exposure and reduction of white matter surface of the brain’s left hemisphere, which has been associated with slower processing speed of information during intelligence testing and severe behavioral problems that include ADHD symptoms and aggression, scientists stated.
While this initial study size was also limited, the researchers are currently undertaking a much larger study in order to confirm and extend their findings.
In previous research, Columbia researchers found that exposure to airborne PAH during gestation was linked to several neuro-developmental disturbances, including developmental delay by age three, reduced verbal IQ at age five, and symptoms of anxiety at age seven.