NEW YORK, Oct. 29 (UPI) -- The combination of maternal physical and psychological stress during fetal development magnifies the effect of each exposure, U.S. and Polish researchers say.
Lead author Frederica Perera, director of the Columbia Center for Children's Environmental Health at the Mailman School of Public Health, reported maternal demoralization -- a measure of psychological distress capable of affecting a mother's ability to cope with stressful situations -- was greatest among children with higher levels of prenatal exposure to polycyclic aromatic hydrocarbons in air pollution.
Polycyclic aromatic hydrocarbons are air pollutants generated by combustion sources such as motor vehicles, coal-fired power plants, residential heating and tobacco smoke. In Krakow, Poland, where the study took place, as in many areas worldwide, coal burning is a significant air pollution source.
Although Krakow has relatively high ambient concentrations of polycyclic aromatic hydrocarbons from coal-burning and vehicle emissions, levels are within the range seen in many other urban areas worldwide.
"Air pollution exposure is ubiquitous and often co-occurs with socioeconomic disadvantage and maternal psychological distress," Perera says in a statement.
"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."
Perera, Dr. Wieslaw Jedrychowski of the University of Krakow and colleagues tracked 248 mother-child pairs from pregnancy through age 9. Personal air sampling was completed during pregnancy to estimate prenatal PAH exposure. Behavioral problems were assessed using the Child Behavioral Checklist, a set of questions to which mothers responded about their child's behavior.
Maternal demoralization was correlated with socioeconomic factors such as material hardship. Levels of maternal demoralization were ascertained by a questionnaire during the second trimester.
The study, published online in the journal Pediatrics, found maternal demoralization was linked with a number of behavioral problems in children including anxiety, depression, attention problems, rule-breaking, externalizing problems and aggressive behavior.