Temperature exposures and mortality: evidence from Russia

Abstract Climate change is expected to disproportionately affect populations in the mid-latitudes, including Russia, which face unprecedented risks due to limited prior heatwave exposure. Yet evidence from these contexts remains limited and comprehensive studies have only recently emerged. This study investigates regional heterogeneities in the temperature-mortality relationship in Russia, focusing on geographic and socioeconomic disparities. A two-stage meta-analysis was conducted, first estimating region-period-specific temperature-mortality associations. In the second stage, these estimates were pooled in a meta-analytic model incorporating geographic and socioeconomic predictors, from which estimates at their different levels were derived. The pooled exposure-response curve showed greater cold-related relative risks (RR = 1.25, 95% confidence interval (CI): 1.22–1.27) than heat-related risks (RR = 1.08, 95% CI: 1.07–1.09) relative to the minimum mortality temperature (MMT = 19.3 °C). Heat-related risks were lower in regions with colder summers and higher air-conditioning (AC) prevalence, and they declined over time. No clear temporal change was observed for cold-related risks and no consistent associations emerged for regional socioeconomic indicators. Overall, these findings confirm the central role of AC as an effective but unevenly distributed heat-adaptation measure in Russia. Additionally, uneven heat-related impacts in cold regions reflects inconclusive empirical evidence of heat-related mortality, necessitating caution when extrapolating exposure-response curves. This study thus offers a comprehensive assessment of temperature-mortality relationships across Russia and leverages rarely used survey microdata to derive household-level indicators, including AC prevalence as a key adaptation factor.