Air pollution exposure tied to higher suicide risk

Clinical takeaway: Consider cumulative air pollution exposure part of the environmental context of suicide risk, alongside the individual factors that anchor assessment. 

Nearly 50,000 people in the US died by suicide in 2024. Prevention works person by person: screening in primary care, psychiatric treatment, crisis response for the patient at hand. Those efforts target the individual factors — psychiatric history, prior attempts, access to means — that typically anchor risk assessment. Environmental exposures have a documented relationship with depression and anxiety, but their bearing on suicide has been harder to pin down.

Earlier reviews examined single exposures in isolation, particulate matter alone or traffic noise alone, and concentrated on acute exposure, leaving the effect of years of accumulated exposure largely untested. A new systematic review and meta-analysis takes the wider view, pooling evidence across air, noise, light, and water pollution against suicide death, attempts, and ideation. It is the first synthesis to put all four exposure types on the same footing and ask whether environment belongs among suicide risk factors at all. 

Pooled odds of suicide death, attempt, or ideation ran 53% higher for each 10 µg/m³ increase in fine particulate matter sustained beyond six months, across six studies, the only association to hold in a consistent direction when the authors restricted the analysis to lower-bias studies. Long-term nitrogen dioxide exposure showed 32% higher pooled odds per 10 ppb across seven studies but did not survive the sensitivity analysis. 

Short-term fine particulate matter exposure barely moved risk. Pooled odds rose 1.4% per 10 µg/m³ of PM2.5 over days to months across 13 studies, and 1% for PM10 across seven. Both associations reached statistical significance but carry little clinical weight. Sulfur dioxide, ozone, carbon monoxide, and noise pollution showed no association in pooled analysis. Water and light pollution had too few comparable studies to pool, and their narrative results were inconsistent. The associations did not differ between men and women. 

The review identified 45 studies published from January 2010 through April 2024, pooling the 29 with compatible effect sizes and synthesizing the rest narratively. Designs ran from case-crossover and cross-sectional through cohort, ecological, and time-series, all in general populations. Studies came mostly from Europe and East Asia, with eight from the US; the three suicide outcomes were pooled as a single endpoint throughout. 

The authors' agenda points at what would make the association usable: studies of how simultaneous exposures act together, and work on whether living in a more deprived area compounds the exposure itself. On the policy side, they argue the findings belong inside environmental regulation and urban planning rather than mental health services alone, naming PM2.5 reduction as the kind of universal intervention the authors have in mind. 

"These findings bring to attention the critical importance of recognising environmental exposures as modifiable risk factors within suicide prevention efforts," the authors conclude. "Integrating environmental health into mental health policy, through cross-sectoral collaboration, pollution reduction strategies and targeted public health interventions, could play a vital role in reducing suicide risk and improving overall population mental well-being." 

Source: Jones SM, et al. (2026 Sep 15) J Epidemiol Community Health. Environmental exposure and risk of death by suicide, attempted suicide and suicide ideation: a systematic review and meta-analysis