Occupational heat stress induced health impacts: A cross-sectional study from South Indian working population

Rising temperature and heat stress risks in the changing climate scenario might potentially affect workers globally, especially the ones with strenuous workload in tropical settings. We used a cross-sectional study design to profile the heat exposures of similar to 1900 workers from eight industrial sectors using a QuesTemp Wet Bulb Globe Temperature (WBGT) monitor, quantified select heat-strain indicators viz., rise in Core Body Temperature, Sweat Rate, and Urine Specific Gravity and evaluated the perceived health impacts of heat stress using a structured questionnaire. Heat exposures (average WBGT: 30.1 +/- 2.6 degrees C) exceeded the Threshold Limit Value for 67% workers and was positively associated with the rise in Core Body Temperature >1 degrees C in 13% and elevated Urine Specific Gravity >1.020 in 9% workers. Heat-related health concerns were reported by 86% workers, and the heat-exposed workers had 2.3 times higher odds of adverse health outcomes compared to unexposed workers (p < 0.0001). Exposure to higher WBGT and adverse renal health among salt-pan workers were significantly associated (p = 0.004), and steel workers had 9% prevalence of kidney stones. Evidence presented clearly points to heat stress as a health and productivity risk factor that could have long-term and irreversible health impacts. In-depth assessments are urgently needed to develop scientifically sound preventative interventions and protective labor policies to avert the adverse occupational health and productivity consequences for millions of workers globally, thereby aiding poverty reduction.