Effects of fine particulate matter bound heavy metals on intentional self-harm deaths in Guangzhou, China, insight from core chemical constituents.

Abstract

Fine particulate matter (PM2.5) is one of the major threats to human health, and may partly responsible for intentional self-harm deaths, while the limited results seemed contradictory. Further analysis on PM2.5 constituents may provide more reliable evidence. Heavy metals are crucial toxic components of PM2.5 that may induce suicide behavior. What role do PM2.5-bound heavy metals play in a threat to intentional self-harm death is still unclear. Two-year data of daily PM2.5-bound heavy metals (including metalloids) and daily intentional self-harm deaths were collected in Guangzhou. Bayesian kernel machine regression, weighted quantile sum, and quantile-based g-computation models were employed to depict the relationships between heavy metals and intentional self-harm deaths. The number of intentional self-harm deaths was 217 and 283 for 2015 and 2016, respectively. A positive correlation was found between the combined effect of the 13 heavy metals and intentional self-harm deaths. Nickel, cadmium, and iron were the primary contributors to this positive correlation. Heavy metal components play significant roles in PM2.5-related intentional self-harm deaths, and targeted source control measures are warranted to protect residents from suicide.