THE INFLUENCE OF AIR TEMPERATURE CONDITIONS AND THEIR CHANGES ON THE MORTALITY IN POLAND

ABSTRACT

The study is an attempt to answer two questions: 1) which of temperature conditions in Poland influence negatively (positively) a human being and cause therefore an increase (decrease) of the mortality? 2) what are the trends of the temperature series influencing the mortality? Monthly data for the index of the mortality and for various thermal characteristics in Warsaw for 39 years from the period 1965-2016 were used in the investigations. There were calculated correlation coefficients between the mortality index and several air temperature series. The level of statistical significance of trends of temperature series influencing the mortality was investigated. The most important results of the study are as follows: 1) statistically significant relations of the mortality in Poland with unfavorable temperature conditions were found in all months of the year except for June and October; 2) in a cool period of the year the mortality is influenced by e.g.: the number of very cold days, the number of days with daily air temperature range ≥8C and ≥12C, the number of days with the maximum temperature >10C and the number of days with day-to-day change of the average daily air temperature of at least ±4C; 3) warm waves in a cool period influence significantly on the decreasing of the mortality in April-May, September, November-December; 4) in a warm period of the year the mortality in Poland is influenced by: hot days and tropical days, tropical nights and the days with the daily air temperature range ≥12C; 5) changes of analysed thermal conditions explain 10% to 42% of the variability of the mortality index in Poland; 6) for some thermal characteristics a lengthening or delaying of the reaction to thermal conditions was observed; 7) series of the number of days with the maximum temperature >10C in April, May and November as well as series of hot days and tropical days in July in the period 1980-2016 show statistically significant increasing trend. Air temperature conditions in Poland are becoming milder for a human being and mortality in a cool period of the year and more and more unfavorable in the summer.

Keywords: air temperature, mortality, Poland, dependencies, bioclimatology.