Supplementary file 1_Fine particulate matter (PM2.5) and suicide in South Korea: an instrumental variable analysis using thermal inversion.docx

Existing studies on the association between air pollution and suicide rely on meta-analyses and simple correlation analyses, which cannot quantify how much the increase in air pollution levels increases suicide rates. This study thus examines the relationship between fine particulate matter (PM_2.5) pollution and suicide mortality in South Korea from 2015 to 2019 using thermal inversions as an instrumental variable to induce exogenous variations in PM_2.5 levels.

The findings suggest that a 1 μg/m³ increase in PM_2.5 pollution is associated with a rise of 0.6628 suicide deaths per 1 million population (β = 0.6628, 95% CI: 0.1049–1.2208). The 2.94% increase in suicide mortality highlights the significant health impact of PM_2.5 exposure. Additionally, this study shows the differentiated effects of exposure to PM_2.5 on the suicide mortality rate.