Heat waves, cold spells and excess mortality among population of four cities of the Arctic macroregion

Abstract

Background: Сlimate warming in Russia is most pronounced in the Arctic macroregion, where it is accompanied by an increase in the frequency and duration of heat waves. This new significant risk factor for population health of the of the largest cities has not yet been sufficiently studied. For the scientific substantiation of plans for adaptation to these phenomen, parameters of such impacts in territories with different types of climate are needed. Aim: Assessment of excess age-specific mortality during heat waves and cold spells among the urban populations of Arctic macroregion; analysis of differences in the results that might be related to the local climate type from marine to continental. Methods: A Poisson generalized linear regression of daily mortality counts was used to calculate relative mortality risks during the periods of extreme heat and cold. This model accounted for possibly lagged effects, seasonal and weekly regularity, and long-term trends in mortality. Pearson 2 statistics was used to test the group differences between the heat-related and cold-related effects, as well as site-specific and age-specific differences. Results: Statistical significance of obtained effect estimates tends to be greater in continental climate than in marine climate. The age group 65 years was more susceptible to the effects of extreme heat and cold than the middle-age group. Cold spells were more harmful to the health of the residents of Murmansk, Archangelsk and Magadan than heat waves, and heat waves were more dangerous in Yakutsk. The greatest values of relative risks were obtained in the age group 65 years: 1,69 (95% CI: 1,342,13) for cerebrovascular disease mortality in Yakutsk during heat waves, and 1,54 (95% CI: 1,182,01) for respiratory disease mortality in Archangelsk during cold spells. Conclusion: The obtained results can be used by the public health authorities in prevention of additional deaths among the subarctic populations during heat waves and cold spells. Keywords: Extreme temperature events; heat waves, circumpolar regions; artic, public health; climate change; mortality rates; preventive medicine.