Effects of Global Warming on Work-Rest Routines for Crop Workers in Appalachia

Background: Workers in outdoor occupations are expected to be at high risk of increased morbidity and mortality, and diminished productivity, as a result of global warming in the 21st century. A previous modelling study of geographic variations in heat-related mortality risk in projected U.S. populations mid-century showed the states of Tennessee, Kentucky and North Carolina to be highly vulnerable. Methods: Under both the RCP4.5 and RCP8.5 emissions scenarios of IPCC AR5, we evaluate the effect of future warming on estimated Wet Bulb Globe Thermometer (WBGT) temperatures using model-simulated future climate variables that were dynamically downscaled by a regional meteorology model for years 2049-2052. Select Appalachian counties in the three states that are presently dependent upon agricultural crop production are the focus of this analysis. Results: Using predicted WBGT temperatures, together with estimated work loads for hand harvesting of crops, alterations in work-rest routines under heat stress prevention guidelines are presented. Conclusions: Assumptions needed to translate these altered work-rest routines into measures of productivity and economic loss are discussed. Issues in extending the modelling to heat-related morbidity and mortality in outdoor worker populations are considered in terms of data gaps and major sources of uncertainty.