A new study links long-term maternal exposure to common air pollutants, both before and after childbirth, to increased risk of postpartum depression.

Symptoms range from anxiety and irritability to suicide, and may lead to cognitive, emotional, psychological, and behavioral impairments in their infants, according to the research.

The study in JAMA Network Open is one of the first to examine the association between environmental factors and postpartum depression that affects approximately 10 to 20% of women after childbirth worldwide.

“Postpartum depression is a major public health problem,” says corresponding author Jun Wu, professor of environmental and occupational health at the University of California, Irvine.

“Due to increased susceptibility of mothers during the antepartum and postpartum periods, identifying modifiable environmental risk factors is important, as it can support future intervention studies on reducing the rate of PPD.”

For the study, the researchers conducted a retrospective cohort study of 340,679 women included in the Kaiser Permanente Southern California electronic health records who had live singleton births at KPSC facilities between January 1, 2008, and December 31, 2016, with a mean age of 30 years.

Ambient air exposures were assessed based on maternal residential addresses using monthly averages of ozone; nitrogen oxides; particulate matter less than or equal to 10 micrometers, such as dust; and fine particulate matter less than or equal to 2.5 micrometers, which contains a mixture of chemicals such as sulfate, nitrate and black carbon.

Overall, a higher risk of PPD was associated with exposure to ozone during the entire pregnancy and postpartum period and with exposure to constituents of fine particulate matter—including organic matter and black carbon—during late pregnancy and postpartum.

Read the full article about air pollution by Pat Harriman at Futurity.