Exposure of heat, vibration & noise and its physiological effects on steel mill industry workers in Selangor

Heat, vibration and noise are the common physical hazards present in many industrial sectors. Manufacturing of steel is one of the industrial activities that involve in many work activities that exposed to heat, vibration and noise. These hazards will increase health complication risk to the workers in the steel industry. Hence, this study is conducted to assess the heat exposure, vibration and noise exposure level and the physiological changes related to each hazards. To assess heat exposure, the ambient temperature of the workstations were measured by using Wet Globe Bulb Temperature (WBGT). One of the workstations had exceeded the Action Limit (AL) and Threshold Limit Value (TLV) of the ambient temperature set by the American Conference of Governmental Industrial Hygienist (ACGIH) with a slight increase in the body temperature of the participants working in that area before and after 8 hours of work. Meanwhile for noise, the exposure level assessed using the dosimeter for 8 hours recorded several work station in the steel mill with mean noise exposures exceeding the PEL of 85-90 dB(A) from the guidelines provided by ACGIH. Physiological changes data for heat hazard were monitored by measuring blood pressure and body temperature while for noise exposure, only blood pressure of the participants were measured before and after 8 working hours and the data collected were analyzed using Paired sample t-test of the IBM SPSS version 23.0. The findings of the study for noise and heat hazard shows significant difference between the blood pressure level before and after 8 hours of working. However, the correlation between the exposures of noise heat hazards towards the blood pressure level has been considered as no statistically significant correlation and showing weak relationships. For vibration, the exposure were assessed using Nordic questionnaires form to determine the physiological changes experienced by the participants at a few selected body parts which are neck, shoulder, elbows, wrist/hands, upper back, lower back, hips/thigh, knees, and ankle/feet. The problems include ache, pain, discomfort, or numbness experienced by the participants. The relationship between the duration of the participants worked as forklift driver and the body parts experiencing problems (eg: discomfort, pain & numbness) for the past 12 months shows participants that have worked as a forklift driver for the longest time in the steel mill have acquired problems such as stiffness and pain at their lower back, neck and shoulder. Several prevention action should be taken to reduce health and safety risk and ensure the workers are in a safe working condition for effective task performance. Further studies should also be conducted with larger sample size to obtain precise results on the physiological effects due to exposure towards these hazards.