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Volume 3, Issue 2 (8-2013)
Abstract
Introduction: Musculoskeletal disorders are the most prevalent problem in the workplace. Unsafe manual material handling is amongst important causes of such disorders. Unsafe manual material handling can result in different musculoskeletal disorders such as acute physical injuries and increase of strain in back, shoulders and arms. United state society of orthopedic surgeons ranked back pain as the most costly disorder, which workplaces are considered to be responsible for most of them. Few studies compare related national and non-national standards in Iran. Therefore, the aim of the present study was to compare Iranian manual material handling regulation, NIOSH equation and MAC method in one of metal casting industries in Tehran, 2001.
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Material and Method: In this cross-sectional study, participants were randomly selected among men workers, working in industry. Data collection was done using MAC data sheet, NIOSH equation and Iranian MMH regulation. Data were Analyzed using stata software and P-value of 0.05 or less was considered significant.
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Result: Results showed an acceptable agreement between Iranian regulation and MAC method as well as Iranian regulation and NIOSH equation. However, no acceptable agreement was observed between MAC method and NIOSH equation.
Hamzeh Mohammadi, Somayeh Farhang Dehghan, Soheila Khodakarim Ardakani, Farideh Golbabaei,
Volume 12, Issue 3 (9-2022)
Abstract
Introduction: Studies show that in many cases, environmental hazardous agents such as heat, noise, as well as chemical pollutants cause adverse health effects through the mechanism of oxidative stress. This study has examined the effect of exposure to noise and whole-body vibration (WBV) on some parameters of oxidative stress (enzyme superoxide dismutase (SOD), total antioxidant capacity (TAC), and malondialdehyde (MDA)) of workers in a foundry industry.
Material and Methods: The workers were selected based on the calculations related to the sample size and taking into account the inclusion criteria as well as completing the informed consent form. The level of exposure to noise and WBV was measured according to ISO 9612 and ISO 2631, respectively. For each worker, the time-weighted average was calculated. The level of exposure of workers to the studied stressors was divided into three categories: low, medium, and high. The blood samples were taken from all participants between 7-9 am. Then, via ELISA method according to the protocol of the kit manufacturer, the samples were prepared and analyzed. Univariate analysis of variance was performed to determine the “effect size” of each physical stressors on the studied parameters.
Results: The mean levels of MDA, SOD, and TAC among participants were 22.48 (11.19) nmol / ml, 61.28 (10.97) U / ml, and 1.64 (0.90) mM, respectively. Among the exposure variables, noise had the largest effect on MDA level (B = 0.090), which was not statistically significant (P = 0.865). WBV had the largest effect on SOD level (B = -1.469) which was statistically significant (P = 0.016). None of the studied variables had a significant effect on the TAC level; however, among the exposure variables, the greatest effect was related to WBV (B = -0.077; P = 0.133).
Conclusion: The effect of noise on oxidative stress parameters was not statistically significant. The effect of whole-body vibration on oxidative stress parameters except SOD was not statistically significant. Noise and WBV had increasing effect on MDA and decreasing one on SOD and TAC levels.
