Environment/Climate Change
Short term fine particulate matter (PM2.5) exposure and “deaths of despair” in Michigan: 2006-2016: a case crossover study Peter S. Larson* Peter Larson Rachel Bergmans Leon Espira
Introduction: Ecological analyses indicate associations of PM2.5 exposure and specific mental health outcomes, but the impacts of individual exposure to air pollutants and broad mental health related mortality are not well understood. This research uses public death records with a case crossover design to assess associations between short term lag exposure to particulate matter 2.5 (PM2.5) and mortality from suicide, alcohol related liver failure and opioid drug overdose.
Methods: Records for all deaths from suicide, alcohol related liver failure, and overdose from 2006 to 2016 were obtained from the State of Michigan. Residential addresses were geocoded, and locations were added to the database. Raster data of daily PM2.5 concentrations at 1km resolution were obtained from the National Aeronautics and Space Administration’s (NASA) Socio-economic Data and Applications Center (SEDAC). We extracted PM2.5 measures for 21 days before the date of death. We used a case crossover design, where everyone serves as their own control. Lag associations of PM2.5 and mortality were then tested using stratified regression models within a directed non-linear modelling framework.
Results: There were 49,031 relevant deaths between 2006 and 2016. There were 19,100 suicides, 8,657 deaths from alcohol related liver failure and 21,374 overdose deaths. Patterns of association of exposure to PM2.5 differed between the types of mortality. Risk of suicide had a positive association with PM2.5 exposure, significantly peaking at lag day 7. For alcohol related liver failure, increased exposure to PM2.5 follow non-significant positive associations with mortality. We found no association of PM2.5 exposure with overdose.
Conclusions: Exposure to extreme levels of PM2.5 at 7-10 days is associated with elevated risk for suicide. Future work should work to explore the exact links between air pollution exposure and develop pro-active means to limit exposure or target at risk persons