Low-income Hispanic women who are exposed to high levels of air pollution during mid-pregnancy may be at greater risk of depression one year postpartum, according to researchers from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) Center for Environmental Health Disparities.

The researchers followed 180 women from early pregnancy to one year after giving birth, tracking their exposure to air pollutants, such as particulate matter, nitrogen dioxide, and ground-level ozone. They found that air pollution exposure, especially mid-pregnancy, increased the risk of depression 12 months after childbirth.

The study drew from the MADRES pregnancy cohort of more than 800 mostly low-income Hispanic women recruited from community health prenatal care providers in Los Angeles between 2015 and 2020.

“Depression is often an underdiagnosed and undertreated health outcome among people of color, and air pollution is a potentially modifiable exposure in contrast to individual risk factors,” said MADRES Center Co-director and lead study author Theresa Bastain, Ph.D. “This study underscores the need to better understand the impact of environmental risk factors during critical periods of exposure.”