This study investigated whether neighborhood socioeconomic burden or the combination of socioeconomic and environmental exposures modified the effect of combined exposure to extreme heat and particulate air pollution on mortality in California. Using a time-stratified case-crossover design (2014-2019), the study found that extreme heat and air pollution, alone and combined, were associated with increased mortality. While higher socioenvironmental and socioeconomic burden was linked to more days with extreme PM2.5 exposure, no consistent effect modification by these factors on mortality risk was observed for combined or separate exposures to extreme heat and PM2.5. The study concludes that neighborhood socioeconomic or socioenvironmental burden did not significantly influence the impact of extreme heat and PM2.5 on mortality in California.

Mehjar Azzouz, Zainab Hasan, Md Mostafijur Rahman, W. James Gauderman, Melissa Lorenzo, Frederick W. Lurmann, Sandrah P. Eckel, Lawrence Palinkas, Jill Johnston, Michael Hurlburt, Sam J. Silva, Hannah Schlaerth, Joseph Ko, George Ban-Weiss, Rob McConnell, Leo Stockfelt, Erika Garcia