Children exposed to air pollution in the womb are at an increased risk of developing mental health issues later in life during their adolescence, a recent study revealed.

The study published in JAMA Network Open investigated how air and noise pollution during pregnancy impact a child's mental health at different stages of development, such as early childhood, and adolescence. Researchers focused on how pollution influenced three common mental health issues: psychotic experiences (like hallucinations and delusions), depression, and anxiety.

To examine this, the team used data from more than 9,000 participants of the Bristol's Children of the 90s birth cohort study. They then linked the early childhood data of the participants with their mental health reports at the ages of 13, 18, and 24 years. By doing this, they could compare the mental health outcomes with levels of outdoor air and noise pollution in South West England at various stages.

"Researchers found that relatively small increases in fine particulate matter during pregnancy and childhood were associated with more psychotic experiences and depression symptoms many years later in teenage years and early adulthood," the news release stated.

The study noted that the association persisted even after taking into account factors such as family psychiatric history, socioeconomic status, population density, deprivation, green space, and social fragmentation.

An increase of 0.72 micrograms per cubic meter in fine particulate matter (PM2.5) during pregnancy was linked to an 11% higher risk of psychotic experiences, while the same increase in PM2.5 during childhood was associated with a 9% higher risk of psychotic experiences. Additionally, exposure to this level of PM2.5 during pregnancy was related to a 10% higher likelihood of depression.

The researchers also noted that the increase in exposure to noise pollution in childhood and teenage years was associated with more anxiety symptoms.

"This is a major concern, because air pollution is now such a common exposure, and rates of mental health problems are increasing globally. Given that pollution is also a preventable exposure, interventions to reduce exposure, such as low emissions zones, could potentially improve mental health. Targeted interventions for vulnerable groups including pregnant women and children could also provide an opportunity for more rapid reductions in exposure," Dr. Joanne Newbury, the study's lead author, said in a news release.