Association between Temperature and Mortality among the Working Age Population in Thailand from 1999 to 2008

This study identifies the temperature-mortality association of the working age (15-64 years)  population in a tropical setting, Thailand. The research covers a 10-year period (1999-2008) and is country-wide. Alternating Multivariable Fractional Polynomial (MFP) regression analysis is used to sequentially build models of the associations between temperature and death rates. Model A is developed to test the links between weather and mortality. Model F produces an optimal weatherdeath model adjusted for air pollution effects and estimates expected mortality with a 4 oC increase in temperature as projected for Thailand by the year 2100. There are highly significant associations between weather variation and mortality for the working age population with a threshold temperature at 36°C (Model A); after adjusting for air pollution effects, the threshold temperature is 33°C (Model F) and forms a J- or U-shaped pattern. The overall increase in mortality among the working age population expected with a 4 oC increase is 11%. The largest effects of maximum temperature on mortality are in the Central region where this effect will be especially prominent, due to urbanization and the heat island effect. Therefore, ongoing future climate change with increasing temperatures will cause death rates of working age Thais to increase substantially and this will have economic impacts in the future.