According to a new study published in the Journal of Epidemiology & Community Health, exposure to air pollutants, particularly fine particulate matter (PM2.5 and PM10) and nitrogen dioxide (NO2), is associated with an increased risk of suicide and suicidal thoughts.
According to the World Health Organization, more than 720,000 people die by suicide globally every year. Although the effects of environmental factors on mental health problems such as depression and anxiety have been widely studied, their direct impact on suicide risk has received comparatively less attention.
To strengthen the evidence, scientists conducted a meta-analysis combining data from 45 studies published between 2010 and 2024. The results showed that short-term exposure to PM2.5 and PM10, as well as long-term exposure to PM2.5 and nitrogen dioxide (NO2), were statistically significantly associated with the risk of suicide mortality, suicide attempts, and suicidal thoughts.
Regarding the underlying biological mechanism, the researchers explain that air pollutants can have neurological effects. In particular, they may contribute to chronic inflammation and neuronal damage, which can impair brain function and negatively affect mood and resilience to stress.
“These findings highlight the critical importance of recognizing environmental exposure as a modifiable risk factor in suicide prevention efforts. Integrating environmental considerations into mental health policies — through cross-sectoral collaboration, pollution reduction strategies, and targeted public health interventions — could play a vital role in reducing suicide risk and improving overall mental well-being at the population level,” the study authors note.
The scientists acknowledge several limitations in the existing evidence, including the small number of studies examining certain indicators and methodological differences between studies. Nevertheless, the analysis indicates that considering environmental factors — particularly the importance of clean air — in mental health prevention strategies is an essential step.
