New research led by the University of Bristol suggests that exposure to air pollution in the womb may lead to certain mental health issues in adolescence. Published in JAMA Network Open on May 28, the study examined the lasting effects of early-life exposure to air and noise pollution on mental health (1^✔ ✔Trusted Source
Prenatal exposure to air pollution associated with increased mental health risks

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Understanding the Long-Term Effects of Early-Life Pollution Exposure

The study indicates a growing body of evidence linking air pollution, composed of harmful gases and particulate matter, to the development of mental health problems. It is believed that pollution can impact mental health through various pathways, including compromising the blood-brain barrier, promoting neuroinflammation and oxidative stress, and directly damaging brain tissue.

Despite adolescence being a critical period for the onset of mental health issues, there has been relatively little research on the associations between early-life exposure to air and noise pollution and mental health.

In this new study, researchers sought to examine the long-term impact of air and noise pollution exposure during pregnancy, early childhood and adolescence on three common mental health problems: psychotic experiences (including hallucinations, such as hearing or seeing things that others cannot, and delusions, such as having very paranoid thoughts), depression and anxiety.

Implications for Mental Health Interventions and Environmental Policy

To investigate this, the team used data from over 9,000 participants from Bristol’s Children of the 90s birth cohort study (also known as the Avon Longitudinal Study of Parents and Children), which recruited over 14,000 pregnant women from the Bristol area between 1991 and 1992, and has followed the lives of the women, the children and their partners ever since.

By linking participants’ early childhood data with their mental health reports at the ages of 13, 18 and 24 years, researchers were able to use this to map against outdoor air and noise pollution in South West England at different time points.

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. These associations persisted after considering many related risk factors, such as family psychiatric history, socioeconomic status, and other area-level factors such as population density, deprivation, greenspace and social fragmentation.

The team found that every 0.72 micrograms per cubic meter increase in fine particulate matter (PM2.5) during pregnancy and childhood was associated with an 11 per cent increased odds and 9 per cent increased odds for psychotic experiences, respectively; while exposure in pregnancy was associated with a 10 per cent increased odds for depression. In contrast, higher noise pollution exposure in childhood and teenage years was subsequently associated with more anxiety symptoms.

Dr Joanne Newbury, Sir Henry Wellcome Postdoctoral Research Fellow in the University’s Bristol Medical School: Population Health Sciences (PHS) and the study’s lead author, said: “Childhood, adolescence, and early adulthood are critical periods for the development of psychiatric disorders: worldwide, nearly two-thirds of those affected become unwell by the age of 25. Our findings add to a growing body of evidence – from different populations, locations, and using different study designs – suggesting a detrimental impact of air pollution (and potentially noise pollution) on mental health.

“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.

“It is important to emphasise that these findings, by themselves, do not prove a causal association. However, other recent studies have shown that low emissions zones appear to have a positive impact on mental health.”

Reference:

1. Prenatal exposure to air pollution associated with increased mental health risks – (https://bristol.ac.uk/news/2024/may/air-pollution.html)

Source-Medindia