Occupational health and productivity loss due to climate change

Introduction
Climate changes since 1980 occurs in most of the world and the continued change until 2050 has been estimated via internationally agreed modeling. Detailed grid cell based climate data and modeling results can be used to estimate regional occupational heat exposures indoors and outdoors. A WHO project on the impacts of climate change on different health concerns was carried out in 2010-2011, and this paper reports results for occupational heat stress. 

Methods
Grid cell (0.5 x 0.5 degrees) climate data for 1975 and 2000 from the Climate Research Unit, UK, and modeled grid cell data for 2030 and 2050 (WHO proposed) were used. Working age population in each grid cell was acquired from IIASA. With exposure-response relationships for heat effects on health and work capacity loss the impacts were calculated. The grid cell results were combined into 21 regions as in the WHO protocol. 

Results
The results show substantial increases of the heat stroke risks and losses of work capacity already in the year 2000 and increasing with time, particularly in regions with many tropical low and middle income countries. As an example, the work capacity losses in 2050 in the worst affected regions, West Africa and India are 14 and 10% respectively. This analysis takes the changing workforce distribution (less agricultural workers in 2050 than in 2000) into account. The impacts on local economic development may be significant and the paper will present various preventive approaches.

Discussion
The problem of increased workplace heat exposures due to climate change and the impacts on occupational health has been given very limited attention so far. Our research shows that the work capacity losses due to climate change may be a very important threat to human health and economic development in low and middle income countries.