Thermal overload in rural areas: the influence of work intensity

Abstract Introduction: Brazilian law requires the use of Wet-Bulb Globe Temperature (WBGT) to monitor work environments where heat may pose a risk to workers’ health; however, such monitoring is often not observed and preventive measures are not taken. Objective: to identify and map the influence of labor intensity on the potential extrapolation of heat exposure threshold limits for outdoor workers in rural areas of northeastern Brazil. Methods: based on Brazil’s Labor Regulatory Standard no. 15 and data from the Brazilian Institute of Meteorology, the software Sobrecarga Térmica (Thermal Overload) was used to estimate WBGT index in the territory from September 1st, 2016 to August 31, 2017. Results: the extrapolation of thermal overload limits was characterized for heavy work in 48%, and for moderate work in 14% of the 132 geographic points investigated, indicating the need for rest stops in more than 50% of the analyzed period. Discussion: decreasing work intensity results in an expressive reduction in thermal overload rates. The restriction to the stimulation of strenuous activities - especially remunerated ones linked to production - in regions historically recognized for their high risk of heat exposure should be implemented as an effective preventive measure for heat stress.