Iran Occupational Health

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 Background and aims: The purpose of this study was to assess the prevalence of respiratory symptoms (phlegm, cough, shortness of breath and wheezing) and lung functional impairments associated with occupational inhalation exposure to carbon black (CB) dust among employees of a rubber industry.

  Methods: All of the eligible, CB exposed, employees of the industry (72 subjects) as well as 69 unexposed employees from the same industry (referent group) were investigated.

 Subjects were interviewed and were given standardized respiratory symptom questionnaires to answer. Furthermore, pulmonary function tests (PFTs) were measured before and after the work shift for exposed subjects and once during the work shift for referent subjects. Furthermore, to assess the extent to which workers were exposed to CB, using standard methods, inhalable and respirable dust fractions of it were measured.

  Results: Levels of exposure to inhalable and respirable CB dust were estimated to be 6.2±1.7 and 2.3±0.29 mg/m³, respectively. Symptoms of respiratory disease such as regular cough, phlegm, wheezing and shortness of breath were significantly more prevalent among exposed workers. Furthermore, compared to unexposed group, significant decreases in mean values of VC, FVC and FEV1 of exposed workers were noted.

  Conclusion: The findings of this study show that exposure to high atmospheric concentrations of CB may result in a significant increase in the prevalence of respiratory symptoms and significant decrements in the mean value of some parameters of pulmonary function with a spirometric pattern consistent with restrictive pulmonary disorders.

  Keywords: Carbon black, Rubber industry, Respiratory disease symptoms, Lung functional impairments

 

 

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  Background and Aim: Casting workers are facing with ergonomics hazards such as overload in Manual Material Handling (MMH) tasks which expose them to risk of work-related musculoskeletal disorders (WMSDs). There are several methods to determine acceptable weight among which, Snook table is one of the oldest one. The aim of the study was to assess prevalence of WMSDs and to investigate MMH tasks by Snook tables among casting workers.

  Materials and methods: This cross-sectional study was conducted among 50 casting workers occupying in all of the five MMH tasks including lifting, lowering, carrying, pushing and pulling. Nordic Musculoskeletal Questionnaire (NMQ) and concise Snook tables were used to gathering required data. Statistical analyses were done using SPSS 16.0.

  Results: The most common musculoskeletal disorders in one year prior to the study were hand wrist disorders (84%), low back pain (74%) and neck disorders (72%), respectively. The Snook tables results indicated that significant differences were found between acceptable weights and workers exerted load in lifting and lowering tasks (p<0.05) and also between acceptable forces and workers exerted force in pushing/pulling tasks (p<0.05). Overall, in most of cases exerted loads exceeded suggested weights.

Conclusion: Regarding to results of the study, ergonomics interventions should focus on redesign of MMH tasks, improvement of workplace physical conditions and providing ergonomics instruments

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Introduction: The present study aimed to compare the filtration performance between neat hybrid electrospun nanofibers consisting of polyacrylonitrile (PAN) polymer and magnesium oxide (MgO) nanoparticles and plasma treated ones in removing fine particles from the air stream.
Methodology: The upper surface of the nanofibers were processed by cold-plasma with a radio frequency power supply (13.56 MHz with a power of 20 watts), argon gas and operating pressure of 0.2 torr. Initial efficiency tests for numerical removal of particles have been done in accordance with standards ISO 29463 and EN 779. Pressure drop and quality factor were determined for the fabricated media. In order to confirm the presence of magnesium oxide nanoparticles in the nanofibers, X-ray diffraction pattern (XRD) was prepared. Analysis algorithms of SEM images were used to calculate the porosity of filters using MATLAB software.
Result: The mean initial efficiency of neat and plasma-treated media was 90.77 ± 6.7 % and 73.66 ± 8.86 % for collecting particles from 10 to 1000 nm, respectively. The initial mean pressure drop of the neat and treated media at the test face velocity was 78.22 ± 3.11 pa and 22.00 ± 2.33 pa, respectively, and their mean quality factor for collecting 10 to 1000 nm particles was 0.029 and 0.010 (Pascal/1), respectively.
Conclusion: By performing plasma treatment, collection efficiency of particle decreased, but with a significant decrease in pressure drop, so neat media ultimately presented the higher score of quality factor than treated one