Psychological distress combined with exposure to air pollution during pregnancy can have an adverse affect on a child’s behavioral development, according to researchers at the Columbia Center for Children’s Environmental Health at the Mailman School of Public Health.

This new study states that maternal demoralization, the measure of psychological distress that is capable of affecting a mother’s ability to cope with stressful situations, is linked to several behavioral problems, including anxiety, depression, attention problems, rule-breaking, externalizing problems, and aggressive behavior. The effects of demoralization were greatest among children with higher levels of prenatal exposure to polycyclic aromatic hydrocarbons (PAH) in air pollution.

“This study shows that the combination of physical and psychosocial stressors during fetal development magnifies the effect of each exposure,” says lead author Frederica Perera, DrPH, PhD, director of the Center. “The findings are of concern because attention problems and anxiety and depression have been shown to affect peer relationships, academic performance, and future well- being of children.”

This research paper is the first ever to assess the interaction between PAH and maternal demoralization on a variety of behavioral issues during childhood.

PAH are generated by combustion sources like motor vehicles, coal fired power plants, residential heating and tobacco smoke. In Krakow, Poland, where the study took place, coal burning is a major air pollution source.

“Air pollution exposure is ubiquitous and often co-occurs with socioeconomic disadvantage and maternal psychological distress,” noted Dr. Perera.

Researchers followed 248 mother and child pairs from pregnancy through nine years of age. Personal air sampling was conducted during the pregnancies to estimate prenatal PAH exposure. Behavioral problems were assessed using the Child Behavioral Checklist, a set of questions mothers answer about their child’s behavior. Maternal demoralization has been associated with socioeconomic factors such as material hardship. Levels of maternal demoralization were measured by a questionnaire given during the second trimester.

Relationships between prenatal air pollution and behavioral or cognitive problems during childhood have previously been observed in the Center’s Mothers & Newborns study in New York City and in the Polish cohort. This new study builds upon prior findings.

Dr. Perera noted, “The findings support policy interventions to reduce air pollution exposure in urban areas as well as programs to screen women early in pregnancy to identify those in need of psychological or material support.”

This study is published in the journal Pediatrics.