Introduction. This article aimed to investigate the effect of heat stress on cognitive performance and the blood concentration of stress hormones among workers of a foundry plant. Methods. Seventy workers within the exposed (35 people) and unexposed (35 people) groups were studied. The wet bulb globe temperature (WBGT) index was measured for heat stress assessment. The cognitive performance tests were conducted using the Stroop color word test (SCWT) before and during working hours. For the assessment of the serum level of cortisol and the plasma level of adrenaline and noradrenaline, blood samples were taken during working hours from both groups. Results. Only for SCWT III was there a significant relationship between heat stress and test duration, error rate and reaction time. The laboratory test results revealed significantly higher concentrations of cortisol, adrenaline and noradrenaline in the exposed subjects than in the unexposed group. There existed a positive correlation between cortisol, adrenaline, noradrenaline and WBGT index and also test duration and reaction time of SCWT III, and number of errors of SCWT I, SCWT II and SCWT III during work. Conclusion. Heat stress can lead to an increase in the blood level of stress hormones, resulting in cognitive performance impairment.

Work Ability Index (WAI) and Its Association with Psychosocial Factors in One of the Petrochemical Industries in Iran: Adel MAZLOUMI, et al. Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Iran—Objectives: In recent decades, work ability index (WAI) has been a common practical tool to measure individuals' work ability in many European, Asian and South American countries. However, there is no study concerning work ability in Iran. The aim of this study was to determine the work ability index in an Iranian petrochemical job setting and to examine its relationship with psychosocial factors.Methods: A cross‐sectional study was conducted among 420 male workers in various occupations. Work ability was evaluated using the WAI questionnaire developed by FIOH; the Job content questionnaire (JCQ) was used to assess psychosocial factors.Results: The mean WAI score was 39.1 (SD=5.7) among workers in the studied petrochemical industry. Multiple linear regression analysis revealed a significant association between mean WAI score and age, job tenure, educational level, rest and sleep status and vocational education. Moreover, the results showed that skill discretion, coworker support and supervisor support were positively associated with the mean WAI score. On the other hand, it was inversely associated with job demands, job strain and job insecurity.Conclusions: This study was the first research to determine WAI in an important industry in Iran. Overall, work ability was in the “Good” category among the workers in the studied field. On the basis of the WAI guidelines, this level should be maintained and promoted to excellent level by providing supportive countermeasures. The WAI score was significantly associated with psychosocial factors. The results showed that even in heavy physical work, factors such as job insecurity, skill discretion, job strain and social support play an important role in maintaining work ability. A positive combination of “psychosocial characteristics” of the job with “individual resources” can promote work ability in such occupations.

Objectives: Maintenance and promotion of employees’ work ability is one of the important social goals. This study is aimed at investigating psychometric properties of the Persian translation of work ability index (WAI). Methods: A total number of 750 employees were randomly selected from car manufacturing and petrochemical industries. Reliability of the questionnaire was determined using test-retest and Cronbach alpha coefficient. Factor analysis was used for assessing construct validity. To determine discriminant validity, the mean score of total WAI was compared between workers with high and low sick leave rate. Results: Intraclass correlation coefficients for its seven dimensions were estimated higher than 0.7. The questionnaire showed a good internal consistency, Cronbach α = 0.78. Factor analysis showed a three-factor structure model for Persian translation of WAI including: mental resources, self-perceived work ability, and presence of disease and health-related limitation. A good level of discriminant validity was observed for all WAI dimensions except the item “work ability regarding work demands.” Discussion: The study findings indicate that the Persian version of WAI questionnaire has good psychometric properties of internal consistency and test-retest showed a good reliability of WAI questionnaire, which is in line with those found in previous studies. Therefore, this tool can be considered as a reliable instrument for assessing work ability.

Evaluation of Mental Workload among ICU Ward's Nurses