Children exposed to high levels of stress at home from early on and high levels of air pollution while still in the womb are more likely to develop attention span and thought problems, such as obsessive thoughts, later in life, according to new research from the University of Colombia.

According to senior author of the research Amy Margolis, “Air pollutants are common in our environment, particularly in cities, and given socioeconomic inequities and environmental injustice, children growing up in disadvantaged circumstances are more likely to experience both life stress and exposure to neurotoxic chemicals.”

For the study, the researchers collected data from the Columbia Center for Children’s Environmental Health Mothers and Newborns longitudinal birth cohort study in Northern Manhattan and the Bronx. Including many participants who identify as African American and Dominican, mothers were asked to wear air monitoring backpacks during their third trimester of pregnancy to measure their daily exposure to air pollutants.

Then, when their children reached 5 years old, the same mothers were asked to report on the amount of stress they experienced, including metrics such as neighborhood quality, material hardship, intimate partner violence, perceived stress and levels of social support. These metrics were then reported every two years until the child reached 11 years old.

In their results, the researchers found that when combined, air pollution and early life stress had a significant impact on several measures of thought and attention problems on children by age 11. In their study, they say that both factors may serve as a “double hit” on shared biological pathways that interconnect attention and thought problems. While it is assumed that stress likely leads to changes in epigenetic expression, cortisol levels, rates of inflammation and thus brain structure and function, how exactly air pollution may affect the brain is still unknown.

Julie Herbstman, associate professor of environmental health science at the University of Columbia said, “These exposures have a combined effect on poor mental health outcomes and point to the importance of public health programs that try to lessen exposure to these critical risk factors, to improve not only physical, but psychological health.”

Sources: News Medical, Wiley Online Library and Science Daily