Evaluation of indoor heat stress on workers of bakeries at Assiut City, Egypt

Abstract

This study investigates indoor heat stress among employees engaged in bakeries in Assiut city. Heat stress is one of the occupational hazards especially in arid climates that impose negative impacts on workers such as heat rashes, heat exhaustion, heat cramps, heat fainting or heat stroke. In this research, 100 subjects were chosen randomly from 20 bakery stations to testify heat stress impacts. Heat stress levels were measured using wet-bulb globe temperature index (WBGT) to evaluate the impacts of environmental factors on the employees. The response of worker’s body to this heat stress is expressed as physiological strain index (PSI) that can be estimated by measuring heart rate and core temperature. Results obtained from WBGT index measurements indicated that the average value of heat stress in bakeries reached 31.6 °C that is exceeding than threshold limit value (28 °C) and action limit (25 °C) recommended by American Conference of Government Industrial Hygienists. In addition, WBGT values were compared with the Egyptian Environmental Law 4/1994 and Egyptian Labor Low 12/2003. PSI values fall in the range of 200 < M (metabolic rate) < 260 indicating that workload in bakeries environment lies in the moderate class. According to the questionnaire data, several workers faced heat disorders including heat exhaustion (23 cases), heat cramps (17 cases), and heat stroke (5 cases). Application of control measures such as engineering control, administrative control, and personal protective equipment should be applied.