Review of the effect of air temperature on human mortality

Abstract

This review article examines evidence of the effects of ambient temperature on human mortality through a narrative literature review of studies published from 1980 to September 2023. The electronic database Scopus was used for the literature search using the following keywords: TITLE-ABS-KEY (((mortality OR death) AND (rate OR cause) AND ((ambient OR air) AND temperature))). The search was limited to the English language and humans, including all disciplines. Studies focused on COVID-19 are not included. In all, the results to 3,964 documents, of which 345 were relevant to the aims of the current review, and 24 additional papers were added through the snowball procedure. The studies were organized into seven subcategories: 1) ambient temperature and mortality, 2) air pollutants as confounders or effect modifiers of the ambient temperature-mortality association, 3) excess mortality due to heat waves, 4) association between ambient temperature 5) The use of thermal indices to estimate the effect of ambient temperature on mortality and age 6) association between ambient temperature and sex and 7) studies that suggest protective/ adaptive measures against excess mortality. Most findings showed that both low and high temperatures have increased mortality, and despite global warming, the effect of low temperatures on human mortality is still high. All studies agreed that the cold effect appears with delay and lasts several days, while heat effects were acute. Seniors and females constitute the most vulnerable age groups to extreme temperatures. Different threshold temperatures were identified in the examined regions, which could be explained by the human adaptation to the climatic conditions, implying that the adaptation and mitigation strategies should be specialized on the unique characteristics of the examined regions, both in terms of the climatic and the demographic characteristics of each study area.