Heat stress in two manufacturing units

Address for correspondence:\ud Katya Koycheva Vangelova\ud Laboratory “Physiology of Labour and Ergonomy”\ud National Centre of Public Health Protection\ud 15 blvd. “Ivan Evst. Geshov”\ud 1431 Sofia\ud tel:02 8056-224, 02 8056-320\ud e-mail: katiavangelova@yahoo.comThe hygienic norms for microclimate are often neglected. The purpose of the study was to assess stress in workers exposed to overheat in the hot period of the year. The microclimate components and wet bulb globe temperature (WBGT) were measured in two units: glass manufacturing unit and iron foundry. Stress was estimated in 15 males, exposed to heat and in a control group of 15 men from each unit. Stress hormones were followed up on three-hour intervals during the early morning shifts: cortisol was assessed using RIA kits, cathecholamines – with spectrofluorimetric method. The heart rate was followed up too. The psychosocial factors were assessed by the questionnaire “My job”. The microclimate parameters and WBGT indicated a high heat load in glass manufacturing unit, and a moderate one, mainly due to infrared radiation in the iron foundry. A highly significant in-crease in the secretion of the stress hormones in the exposed to heat workers in both units was found, more pronounced and considerable in the glass manufacturing unit. The over-heat rises a considerable increase in the activity of the stress system, more expressed with high heat load. In view of the possible health hazards, better control and measures for re-duction of heat load and a prophylactic program are recommended