Environmental factors and daily suicides: a time series analysis

Background This study investigated the association between weather, air pollution, and suicide risk in Sousse. Methods A two-time series analysis examined suicide cases recorded in the forensic service of Farhat Hached University Hospital of Sousse, confirmed by autopsy, over seven years (2010-2016). Climate data were retrieved from the Monastir-Airport weather station, and air pollution data were obtained from the National Agency for Environmental Protection’s modelling platform. Results During the study period, 118 suicides were recorded, with the highest number (19.5%) occurring in 2012. Multiple binary logistic regression analysis revealed that autumn and a decline in NH3 were independently associated with a decreased risk of suicide (p=0.045; ORa: 0.57 CI95% [0.33-0.98], p= 0.009; ORa: 0.24 CI95% [0.08-0.71], respectively). Conversely, a 1 ppm increase in PM10 was associated with a 2.5% increase in suicide risk (p<10-3; ORa: 1.02 CI95% [1.01-1.03]). Conclusions Environmental factors, including seasonality and air quality, may provide valuable insights into suicide risks. Understanding the influence of these factors may have implications in preventive strategies.