An Ergonomics Evaluation of Job Stress in a Typical Hot Industry

摘要

Twenty-four workers, randomly selected from a forging plant, were studied to ascertain impact of occupational work-load on the physiological functions during some typical jobs comprising Ⅰ) LOADING Ⅱ) UNLOADING Ⅲ) HELPING and Ⅳ) FORGING, routinely performed in a Forge Shop. Environmental heat load was assessed through measurements of 'Ambient Air Temperature', 'Humidity', 'Wind Velocity', and 'Radiant heat'; the physiological demand was evaluated in terms of 'Energy Cost', 'Heart Rate' and 'Oral Temperature'. Findings reveal that the environmental heat load, expressed as CET, was quite severe (around 32.0°C) with intense thermal radiation. Extreme condition was observed 38.9°C, which is well above the permissible limit (i.e 29.5°C) for day to day industrial work. From the consideration of the energetic workload ranged from 3.5 to 6.0 koal min~(-1), the jobs could be graded 'Moderate' to 'Heavy' which could, however, be categorized 'Heavy' to 'Very Heavy', based on the circulatory stress. Discrepancies in the job-severity are due to superimposed effect of climatic stress coupled with physical workload. The oral temperature records also indicate alarming physiological response. It could, thus, be concluded that the workers on the forging tasks have to experience a considerable degree of occupational stress arising out of environmental heat load and physical activities, and hence the consequent undue strain in their day to day occupational work. Appropriate recommendations are suggested. Details are discussed in the paper.