Air pollution, a problem that affects people all over the globe, can impact a person’s physical health but new research shows that it can also cause poor mental health.  This week's study shows a relationship between exposure to air pollution and post-partum depression.  

Post-partum depression (PPD) is an increasing, but less-talked-about, mental health problem. It is one of the major depressive disorders and a primary reason for childbirth complications. Approximately, 10 to 20% of the women worldwide experience post-partum depression symptoms, and almost 9% of mothers are diagnosed with PPD. Mothers with PPD have various symptoms like depressed mood and/or anxiety; they are also at higher risk of other illnesses and even death. PPD is not only a problem for mothers, it also affects their children. Infants born to mothers with PPD are at higher risk for developing emotional and behavioral problems.  

Previous research has shown that there is an association between air pollution and poor mental health. This week’s article adds to this understanding by studying long-term exposure to air pollutants and PPD experiences in mothers.¹ The study included women who gave birth between January 2008 and December 2016 in Southern California. PPD assessment was done using interviews and pharmacy records. During their first postpartum visit, the study participants were assessed for PPD. Mothers with positive results were followed up for further assessment. The daily air pollution measures from 2007 to 2017 were obtained from the US Environmental Protection Agency (EPA). The researchers then measured each participant’s daily exposure to common air pollutants such as ozone, nitrogen dioxide, Particulate Matter (PM) size 2.5 µm (PM2.5), and PM size 10 µm (PM10).  

Results show that during the period of late pregnancy and post-partum, long-term exposure to PM10 and PM2.5 can lead to PPD. Exposure to ozone during the entire pregnancy period and post-partum period might cause PPD. The reason behind this is that air pollutants can interfere with brain activity and affect brain function. These findings show that air pollution can lead mothers to experience PPD. With increasing air pollution, the cases of PPD will rise and might lead to more health problems in the future. By working to reduce air pollution we can also help reduce the number of mothers suffering from PPD. 

Post-partum depression (PPD): a mood disorder or depression that occurs in mothers after birth of a baby. It is usually a short-term disorder.

Particulate matter (PM): a mixture of solid particles and liquid droplets found in air. PM2.5 are small particles (< 2.5 µm)that are often a result of combustion (such as from cars) while PM10 are larger (< 10 µm), but still very tiny, particles such as dust, pollen, and smoke.