Physiological Responses to Occupational Heat Exposure Among Male Agricultural and Brick-Field Workers in Eastern...

Occupational heat exposure is considered a major health concern for workers performing strenuous work during hot environmental conditions. This cross-sectional study aimed to assess the biochemical and physiological responses to occupational heat exposure among agricultural and brick-field workers working in hot environmental conditions in eastern India. A sub-sample of 20 agricultural workers and 20 brick-field workers was selected from the larger sample of 200 workers each to assess the physiological and biochemical responses to hot environmental conditions during the summer and winter seasons. Environmental heat exposure was measured using the time-weighted average Wet Bulb Globe Temperature (TWA-WBGT in °C). Venous blood samples were collected to measure the levels of sodium, potassium, and aldosterone. Active sweat gland responses were measured using the modified starch-iodine technique. Multivariate general linear models of repeated measures were used to measure the effect of the following factors: season, exposure day, and occupation. The multivariate analysis showed significant seasonal effects on serum potassium, sodium, and aldosterone levels, and that exposure day influenced only potassium, not occupation. The monitoring sessions showed normal physiological levels of electrolytes in both occupational groups. Sweat gland activation was also significantly higher during the summer season. TWA-WBGT values above 23°C-25°C are associated with a higher probability of hyponatremia, as revealed by the receiver operating characteristic (ROC) analysis. These findings highlight the physiological adjustments associated with occupational heat exposure and emphasize the importance of hydration and heat mitigation strategies for outdoor workers.