A new study has found a link between an exposure to air pollution during pregnancy and problems with children regulating their thoughts, emotions, and behaviors.
The study by researchers at the Columbia Center for Children’s Environmental Health at Columbia University’s Mailman School of Public Health and New York State Psychiatric Institute examined the effects of being exposed to a common air pollutant, polycyclic aromatic hydrocarbons (PAH), on self-regulating behaviors and social competency during childhood.
Children with poor self-regulation skills have difficulty managing disruptive thoughts, emotions, and impulses, the researchers explain, adding poor social competency limits their ability to get along with others.
PAH are common in the environment, coming from emissions from motor vehicles; oil, and coal burning for home heating and power generation; tobacco smoke; and other combustion sources.
Prenatal exposure to PAH has been associated with ADHD, anxiety, depression, and inattention, as well as behavioral disorders, which are thought to be related to deficits in self-regulation, according to researchers.
For the new study, lead investigator Amy Margolis, an assistant professor of medical psychology in the Department of Psychiatry at Columbia University Medical Center and New York State Psychiatric Institute, and her colleagues analyzed maternal blood samples and child tests results from 462 mother and child pairs, from pregnancy through early childhood.
Maternal exposure to PAH was determined by the presence of DNA-PAH adducts in a maternal blood sample.
Children were then tested with the Child Behavior Checklist at ages three to five, seven, nine, and 11. Scores from these tests were then used to create a composite score for the Deficient Emotional Self-Regulation Scale (DESR). Higher scores on the DESR indicated reduced capabilities to self-regulate.
The researchers found that children whose mothers had higher exposure to PAH in pregnancy had significantly worse scores on the DESR at ages nine and 11.
Over time, children with low exposure followed a typical developmental pattern and improved in self-regulatory function, but the high-exposed children did not, underscoring the long-term effect of early-life exposure to PAH, according to the study’s findings.
Additionally, the researchers discovered that the DESR score had an effect on tests of social competence, indicating that self-regulation is an important factor in developing social competence.
The evidence that prenatal exposure to PAH leads to long-term effects on children suggests that this exposure may be an important factor in a range of childhood mental health problems, the researchers noted.
That may be because prenatal exposure to PAH damages neural circuits that direct motor, attentional, and emotional responses, the researchers suggest. These deficits in self-regulation may then predispose children to becoming engaged in high-risk adolescent behaviors, researchers added.
“This study indicates that prenatal exposure to air pollution impacts development of self-regulation and, as such, may underlie the development of many childhood psychopathologies that derive from deficits in self-regulation, such as ADHD, OCD, substance use disorders, and eating disorders,” concluded Margolis.
The study was published in the Journal of Child Psychology and Psychiatry.