Objective and subjective assessment of environmental ergonomic factors in packing industry

Abstract

Introduction: Environmental ergonomic is a part of ergonomics which deals with the effects of physical factors of the workplace including noise, light and thermal conditions on employee's health, safety, comfort and performance. Purpose: This study was conducted to investigate the relationship between objective and subjective assessments of environmental ergonomic factors in 3 packing plants in Saveh, Iran. Materials and methods: Objective noise, lighting and thermal assessments were carried out by noise dosimetry, illuminance measurement, and WBGT methods, respectively. These data were then compared with the current standards. In addition, subjective assessments of the environmental factors including noise, lighting and thermal conditions and their influences on employee's satisfaction, performance, safety and health, were conducted using a questionnaire. Finally, the study evaluated the relationship between objective and subjective assessments of the environmental factors in the workplace. Findings: The recommended noise, illuminance and heat levels were not met in 41.5%, 46.9%, and 55.5% of the work areas. Satisfaction with noise, lighting and heating condition in the work environment were 35.7%, 28.5% and 8.6%, respectively. Adverse physical, psychological and haring loss effects due to noise were reported by 22.6%, 22% and 18.8% of the employees, respectively. Adverse effects of lighting condition on job performance, changing posture for better viewing of the work area and eye tiredness were reported as 64%, 33% and 31% of the employees, respectively. Job performance decrements due to noise, lighting and heating condition were reported by 50.4%, 64% and 46.1% of the respondents, respectively. The adverse effects of noise, lighting and heating conditions on safety were reported by 10.2%, 5.4% and 13.2% of the employees, respectively. The results indicated a relatively good agreement between the objective noise, illuminance and heat measurements and the employees' perception of these environmental factors. Conclusion: Based on the findings of the study, it is recommended that quantitative physical measurements should be supplemented by qualitative subjective assessments to improve the understanding of environmental factors in working environments and to design a better workplace in terms of the employee's satisfaction, performance, health and safety.