Suicide and suicidality in people exposed to pesticides: A systematic review and meta-analysis

Exposure to pesticides has been proposed to be a positive association in suicide and suicidality. Many studies have explored this topic, but have reported inconsistent findings. We carried out a systematic review and meta-analysis of the now existing evidence on the association between pesticide exposure and the risk of suicide and suicidality. We searched PubMed, EMBASE and Web of Science databases for studies published up to February 1, 2023. For studies that provided detailed data, we applied quantitative meta-analysis to calculate Odds ratio (OR) with 95% Confidence Intervals (CIs) to evaluate the results. Heterogeneity among the included studies was assessed using Cochran's Q test, I2 statistic and tau-squared (τ2). Publication bias was evaluated by funnel plots, Egger's test, and Begg's test. In addition, subgroup analyses according to pesticides category and geographical area were performed. 2906 studies were initially identified, and 20 studies were eventually included. Fifteen of the studies were on suicide deaths and suicide attempts, and five were on suicidal ideation. Pesticide exposure was positively related to suicide deaths and suicide attempts (pooled OR = 1.31; 95%CI: 1.04–1.64, p < 0.001) and suicidal ideation (pooled OR = 2.43; 95%CI: 1.51–3.91, p = 0.015). In the subgroup analysis, mixed pesticide type (pooled OR = 1.55; 95%CI: 1.39–1.74) increased the risk of suicide deaths and suicide attempts. The results of the analysis by geographic area showed that the risk of suicide deaths and suicide attempts with pesticide exposure was 2.27 (95%CI = 1.36–3.78), and 1.33 (95%CI = 1.14–1.56) in Asia and Europe, respectively. The risk of suicidal ideation caused by pesticide exposure in Asia and America were 2.19 (95%CI = 1.08–4.42) and 2.99 (95%CI = 1.76–5.06). In conclusion, pesticide exposure may increase the risk of suicide and suicidality based on the current evidence.