The Effect of Occupational Noise Exposure on Serum Cortisol Concentration of Night-shift Industrial Workers: A Field Study

BACKGROUND: In both developed and developing countries, noise is regarded as the most common occupational hazard in various industries. The present study aimed to examine the effect of sound pressure level (SPL) on serum cortisol concentration in three different times during the night shift. METHODS: This case–control study was conducted among 75 workers of an industrial and mining firm in 2017. The participants were assigned to one of the three groups (one control and two case groups), with an equal number of workers (25 participants) in each group. Following the ISO 9612 standard, dosimetry was adopted to evaluate equivalent SPL using a TES-1345 dosimeter. The influence of SPL on serum cortisol concentration was measured during the night shift. The serum cortisol concentration was measured using a radioimmunoassay (RIA) test in the laboratory. Repeated measure analysis of variance and linear mixed models were used with α = 0.05. RESULTS: The results indicated a downward trend in the serum cortisol concentration of the three groups during the night shift. Both SPL and exposure time significantly affected cortisol concentration (p < 0.0001, p < 0.0001). Conversely, age and body mass index had no significant influence on cortisol concentration (p = 0.360, p = 0.62). CONCLUSION: Based on the obtained results, increasing SPL will lead to enhancement of serum cortisol concentration. Given that cortisol concentration varies while workers are exposed to different SPLs, this hormone can be used as a biomarker to study the effect of noise-induced stress.

relationship between mental workload and general health among welders of Tehran Heavy Structure Metal Company

Mental workload is one of the factors that influence individuals' performance in the work environment as well as their efficiency and productivity. The present study aimed at examining the association between mental workload and general health among welders of Tehran Heavy Structuress Metal Company.This cross-sectional study was conducted in 2016. The sample included 100 welders who were working in Tehran Heavy Structures Metal Company. Sampling was done through conducting a census. A demographic questionnaire, General Health Questionnaire-28 [GHQ-28], and National Aeronautics and Space Administration Task Load Index [NASA-TLX] mental workload questionnaire were used to collect data. The obtained data were fed into SPSS [version 22] and analyzed through Chi-square, one-way ANOVA, Kruscal Wallis Test, Pearson product moment correlation, and Mann-Whitney U Test.The results showed that the participating welders had an average age of 36.16 +/- 7.81, an average work experience of 9.65 +/- 5.83, and a BMI of 25.95 +/- 3.39 kg/m2. The mean and standard deviation of the overall score of welders' mental workload were 65.88 +/- 21.15. The cut-off scores for the total mental workload questionnaire and the subscales were respectively set at 23 and 6. The results demonstrated that 26% of the welders were suspected of mental disorder. Furthermore, the results of Pearson correlation indicated that there was no significant relationship between the overall score of NASA mental workload and that of general health [p-value>0.05].Welders' mental workload is relatively high. Therefore, further research should be conducted in order to identify main risk factors that lead to mental and health disorder. Future studies should also be performed to present some solutions for te purpose of decreasing or preventing these side effects among welders as much as possible

relationships between parenting styles and addiction potentiality among students

Family is considered as the most fundamental and basic shaping, and underlies drug abusing. This research aimed to investigate the relationships between parenting styles [authoritative, permissive and despotic] as one of the most effective family factors on child growth and addiction potentiality among the students. The statistical population of research consisted of all student of Medical Ilam University of Medical Sciences in the second semester 2012-2013 academic years. Therefore 220 students selected with multistage random sampling, and completed the Baumrind parenting styles questionnaire [1972] and addiction potentiality [Zargar, 1996]. Data has been analyzed by Pearson correlation tests and regression using SPSS 16. The outcomes of pearson correlation analysis showed that there have been negative relationships between authoritative parenting style and addiction potentiality and between permissive, despotic parenting styles and addiction potentiality positive and meaningful relationships reported. The results of regression analysis showed that parenting styles [authoritative, permissive and despotic] described about 38 percentages of addiction potentiality variances, too. According to present research results, parenting styles is one of the most effective reasons on students' tendency to the drug abusing. With this mind, the hygienic officials and activists should make suitable policies to increase parent's information in parenting styles education field