Long-term effects of ambient air pollutants on suicidal ideation in China: The Henan Rural Cohort Study.

The association between ambient air pollutants exposure and suicidal ideation (SI) has rarely been explored, especially in Chinese population. Therefore, we aimed to investigate the long-term effects of ambient air pollutants on SI among a Chinese rural population. We recruited 29997 participants from the Henan Rural Cohort study in 2016–2017. SI was evaluated by using the ninth item of the Patient Health Questionnaire-9 (PHQ-9) in the baseline survey. We adopted a satellite-based spatiotemporal model to estimate participants' exposure to particulate matters (PMs) (PM with an aerodynamic diameter ≤1 μm (PM 1), ≤2.5 μm (PM 2.5) or ≤10 μm (PM 10), respectively) and nitrogen dioxide (NO 2), and then calculated the 3-year average concentrations of the four pollutants. We used logistic regression models to explore the association between long-term exposure to ambient air pollutants and SI. In addition, we conducted several stratified analyses to examine effect modification of selected factors. The odds ratios (95% confidence intervals [CI]) of SI in response to each 1 μg/m3 increase in PM 1 , PM 2.5 , PM 10 and NO 2 concentrations were 1.08 (1.01, 1.15), 1.10 (1.02, 1.19), 1.05 (1.01, 1.09) and 1.12 (1.04, 1.21), respectively. Individuals exposed to PM 1 , PM 2.5 , PM 10 or NO 2 concentrations in the fourth quartile had a 1.36-fold (95%CI: 1.08, 1.72), 1.69-fold (95%CI: 1.05, 2.72), 1.49-fold (95%CI: 1.09, 2.05) or 1.71-fold (95%CI: 1.15, 2.85) risks of SI, compared to the ones with corresponding air pollutants in the first quartile. Besides, the risks of SI increased with the quartiles of air pollutants (PM 1 : P trend = 0.002, PM 2.5 : P trend = 0.003, PM 10 : P trend = 0.010, NO 2 : P trend = 0.010). Stratified analyses suggested that males, highly educated participants, ever-drinkers and people aged range 36–64 years were more vulnerable to the adverse effects of air pollutants. This study provided evidence for the long-term effects of ambient PMs and NO 2 on SI in rural Chinese adults, particularly for males, highly educated participants, ever-drinkers and people aged range 36–64 years. • We explored effects of air pollutants on suicidal ideation in rural China. • Chronic air pollutants exposure was related to elevated risk of suicidal ideation. • Specific subgroups were more vulnerable to the adverse effects of air pollutants. • Our findings are of highly relevant to public health policy and practice in China. [ABSTRACT FROM AUTHOR]