Air Quality and Suicide

Suicide is among the world's leading causes of death. Following a period of decline, suicide rates are on the rise in the United States. While much work has focused on the roles of economic conditions and substance abuse on suicide, exposure to pollutants has received almost no attention as a risk factor. While pollution has been shown to increase depressive symptoms, increase the likelihood of being suspended from school or committing crimes, and affect health and performance on exams, we know little about the effects of pollution on self-harm. We use detailed cause of death data compiled from all death certificates between 2003 and 2010 to calculate daily death rates by suicide (overall and by sex and age groups) in each county in the U.S. We plan to estimate the impact of days with high air pollution (captured by the log of the Air Quality Index (AQI)) on contemporaneous suicide rates compared to other days in the same month, year, day of the week and state-county with lower air pollution, conditional on the same weather and total population. We will also investigate the impact of pollution in the 4 weeks leading up to and containing a given day in which a suicide occurred. This work has important implications for suicide prevention. If we know that certain places are more likely to experience increases in suicides on certain days, policymakers and practitioners will be better able to target resources to those places. In addition, this work has implications for understanding the full costs of airborne pollutants. If certain types of pollution increase the risk of suicide, then targeted regulatory efforts might decrease the suicide rate.