Journal of Health and Safety at Work

Introduction: Heat stress in workplaces cause multiple problems such as thermal stresses, thermal discomfort and in more severe cases may lead to accidents and diseases related to excessive heat. The aim of this study was to evaluate heat stress adopting WBGT Index in some small enterprise in Qom city and also to examine the relationship between WBGT and physiological indices.

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Material and Method: This Cross-sectional study was conducted in 25 small workshops in Qom city including of 10 indoor and 15 outdoor workshops in August 2012. WBGT were measured according to the ISO7243 standard. The physiological responses including pulse rate, systolic and diastolic blood pressure were measured among 25 workers (one from each workshop).

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Result: The average WBGT index for indoor job were 27.55 Ċ among auto body repair, 27.45 Ċ in mechanics, 24.64 Ċ in painters, 26.73Ċ in welder and 25.89 Ċ in manufacturing doors and windows makers. For outdoor jobs as auto body repair, mechanics and painters it was 30.01 Ċ, and for welders and doors and windows makers 28.52 Ċ. Compared to the standard of ISO7243 WBGT all small workshops were higher than threshold limit. Auto body repair (30.22 Ċ) and painting (30.03 Ċ) workshops had highest WBGT. Average WBGT in auto body repair (as a job with most exposed to the open space and solar radiation) with welder and doors and windows, showed statistically significant differences T-test using WBGT with pulse rate, systolic and diastolic blood pressure did not have statistically significant (P>0.05). The findings indicated that workers are exposing to heat stress and doing more researches and representing preventive counter measures for the workers in this field are essential.

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Conclusion: Heat stress in almost all of the studied workplaces are higher than the recommended limits, and the outdoor workshops had the highest thermal stress, although heat stress did not show a significant correlation with the studied strains.

Introduction: Work-Family Conflict can influence the physical and mental health of workers as a social parameter. The aim of this study is supposed to provide theoretical model of relationship between work-family conflict and occupational accidents, taking into account parameters such as job stress and general health of employees in a steel manufacturing industry.

Material and Method: Research population included workers of steel department of a steel manufacturing industry. This research was a cross-sectional study, and 270 individuals were selected in two groups, with an accident experience during lasts 5 years (case) and without (control). They responded to questionnaires including 4 parts, demographic, 18 questions of work-family conflict, 35 questions of job stress and, 28 questions of general health. Data were analyzed and introduced using AMOS software.

Result: Result showed that the model present an excellent goodness of fit and all of factors were significant between parameters (p<0.001). In addition, individual health and job stress with high coefficient could affect work-family conflict and work-family conflict was effective in the event of occupational accidents.

Conclusion: Reducing work-family conflict as a social parameter affecting stress can be effective in the reduction of occupational accidents. The organizational management system with optimization of this important factor can upgrade its level of occupational safety.

Introduction: Control room is one of the most important working environments that require optimal performance of individuals to minimize errors. Lighting is one of the environmental factors affecting the operation of the control room operators. Providing optimal lighting in the control room is very important. The purpose of this study was to determine the effect of light on workload, sleepiness, eye fatigue, and satisfaction of individuals from light conditions.

Material and Method: This was an interventional study conducted in a control room of a power plant. Intervention in the control room lighting was performed with two lighting systems including fluorescent lamps (4000 Kelvin, 200 lux) and LED lamps (4,000 Kelvin, 400 lux). Sixteen operators were evaluated under the two lighting systems in terms of workload, sleepiness, eye fatigue and satisfaction of individuals from light conditions.

Result: According to the results, eye fatigue significantly decreased after intervention (p (0.004>. Also, the higher light intensity, significantly decreased the level of sleepiness (p <0.001). In the study of workload, the amount of mental workload (p <0.001) and effort (p <0.03) decreased significantly, after intervention and the increase in the intensity of light; but physical demand, temporal demand, performance and frustration had no significant difference with the results before intervention.

Conclusion: In general, a combination of fluorescent and LED lighting systems, with 400 lux intensity, can provide optimal functional and mental conditions for control room operators. The illumination intensity of 400 lux in terms of workload, sleepiness, eye fatigue and the degree of satisfaction of individuals from light conditions provides a much better environmental condition than 200 lux.