مجله مهندسی بهداشت حرفه ای
سال دوم شماره 2 (تابستان 1394)

: In recent years, there has been a dramatic increase in the application of nanotechnology in industries and the number of workers occupied in different processes of research on and construction, production and residue disposal of products containing nanoparticles. Despite this growth, however, there is still a dearth of information on the risk of occupational exposure to these materials. Due to the growing application of nanoparticles in the workplace, selecting suitable sampling and characterization techniques and instruments as well as investigating their efficiency for the evaluation of occupational exposure is very important. The present review study was conducted to introduce the methods and instruments used for evaluating occupational exposure to nanoparticles with an emphasis on the results of the existing literature on methods and instruments of evaluating occupational exposure to nanoparticles and the different contributing factors and conditions through library resources. The results of this study demonstrate that, in spite of the wide application of nanotechnology in the workplace, a reliable, international and standard method for evaluating occupational exposure to nanoparticles is still lacking. This study also shows that occupational exposure to nanoparticles can be evaluated through modern instruments that identify and characterize nanoparticles in terms of their number, mass concentration and surface area. The Scanning Mobility Particle Sizer (SMPS) was the most widely-used instrument for measuring the number and size distribution of particles. The accuracy and precision of the methods and instruments used for evaluating the exposure to nanoparticles can be investigated in future research as a way of establishing a suitable and reliable evaluative standard.

Employee productivity depends on the individuals’ ability to work. As musculoskeletal disorders are considered one of the main causes of reduced work ability and disability, the present study was conducted to assess work ability among workers of Shomal Cement Co. and to determine the relationship between the Work Ability Index (WAI) and the severity of musculoskeletal disorders. The present analytical, descriptive, cross-sectional study was conducted on 175 workers of Shomal Cement Co. occupied in different job categories. The work ability of the employees was assessed using the WAI and the prevalence of musculoskeletal disorders among them was then assessed using the Nordic questionnaire. The data obtained were analyzed in SPSS-16 using statistical tests including the Pearson Correlation Coefficient and the Analysis of Variance. The mean value and standard deviation of the WAI in the employees of Shomal Cement Co. was calculated as 38.37±5.80. The Pearson correlation coefficient obtained showed no significant correlations between the WAI and the variables of age and work experience (P-value=0.355 and 0.096). The ANOVA revealed a significant correlation between the WAI and the severity of musculoskeletal disorders (P-value<0.001). The study showed that the majority of participants had a good work ability and that musculoskeletal disorders are significantly related to work ability the prevalence and severity of musculoskeletal disorders can thus be reduced through reducing or eliminating the risk factors causing the condition.

Farmers are exposed to numerous risk factors for musculoskeletal disorders, such as awkward postures, highly repetitive movements and carrying heavy loads. The prevalence of these symptoms is therefore predicted to be significant in this group of workers. The present study was conducted to determine the prevalence of musculoskeletal disorders among farmers in Zarand county in Iran. The present descriptive, analytical, cross-sectional study was conducted on 350 farmers in Zarand. Participants were selected through simple random sampling. Data were collected by community health workers at health houses of the region using the Nordic Questionnaire. The data obtained were then analyzed in SPSS-18. A total of 98% of the farmers were male, 98.9% were married and 62.9% had a normal BMI. The highest prevalence of musculoskeletal disorders was perceived in the knees (58.3) and the lowest in the elbows (8.19) over the last 12 months. The results of statistical tests showed a significant relationship between age and the prevalence of musculoskeletal disorders in all the 9 body parts examined. A significant relationship also existed between the frequency of these disorders and variables including weight and height. Work experience and good exercise habits reduced the likelihood of developing these disorders. The prevalence of musculoskeletal disorders was significant among the farmers examined. Performing ergonomic interventions aimed at modifying body posture at work, designing useful tools and performing exercises at set intervals are measures that should be taken to help farmers keep healthy.

Industrial ventilation systems and dust collectors are effective solutions to reduce particulate emissions in the workplace and environmental in mineral processes. In this study, Local Exhaust Ventilation System and dust collectors for control of emitted silica, coke, silicon carbide dusts from crushing unit was designed and evaluated.: Local Exhaust ventilation system based on standards and guides was designed and implemented after field study of the processes and sources of air pollutants. A set comprised of the four parallel cyclones (Stairmand model) and a new design of the scrubber had been used for dust control. After set-up of systems, its effectiveness in reducing the exposure of workers in the workshops and dust collecting were assessed. Test results were significant differences between the concentration of particles in both on and off the ventilation system revealed (P <0.05). The system has been implemented as means of personal exposure to pollutants and environmental emissions were reduced 93.01% and 64.64%, respectively. Also, alone and integrated collection efficiency of cyclone and scrubber, were 94.2%, 59.05% and 97.4%, respectively. The results show good agreement with the values of the parameters ventilation system was designed. Implementation of integrated dust collectors is a good option in industries that have the financial and technical constraints to improve change processes and devices. This method with attainment to health and environmental standards not only can be resolve of the pollution problems, but also will be economically justified of such projects with reduction of depreciation expense and dust recycling.

Job satisfaction and high levels of general health in workers can lead to their better performance, the reduction of workplace accidents and ultimately the improved productivity of the organization. The present study was therefore conducted to assess the relationship between these variables and the incidence of workplace accidents in medium-scale industries in 2014-15.: The entire population of workers in three medium-scale industries (n=163) entered the study. Data collection was conducted using Goldberg’s General Health Questionnaire, the Minnesota Satisfaction Questionnaire and a demographic questionnaire containing items on age, gender and the number of workplace accidents. The data obtained were then analyzed in SPSS-20 using the multiple-linear and the Poisson regression models. The general health scores obtained by the participants ranged from 4 to 68 and had a mean and standard deviation of 25.87±13.085. The job satisfaction scores obtained ranged from 31 to 100 and had a mean and standard deviation of 63.45±11.462. The Poisson regression model showed that the level of education, age, physical symptoms and anxiety and insomnia had a significant relationship with the rate of accidents (P<0.05). The model also showed a significant relationship between job satisfaction and general health (=-0.417 and P =0.001). The general health of the study participants can be said to be unacceptable and their job satisfaction to be medium. Devising plans for controlling and improving psychological and psycho-social factors such as job satisfaction is essential for workplace decision-makers, particularly in small and medium-scale industries. These plans can facilitate the achievement of higher health and safety levels in workers.

Perceived social support in the personnel of any organization is an important psychological factor that affects the efficiency of the workforce and exerts direct and positive effects on the their quality of life. The present study was conducted to investgiate the level of perceived social support in the personnel of a manufacturing industry in Urmia and to determine its relationship with certain demographic variables. The present descriptive study was conducted on 156 personnel of a manufacturing industry in Urmia. Data collection was conducted using the Perceived Social Support Questionnaire. The results obtained were then analyzed using descriptive and analytical statistics, including the chi-squared test and the one-way analysis of variance. The mean value of perceived social support from coworkers (3.36±0.72) was higher than the mean value of perceived social support from managers (2.99±0.65). Perceived social support from coworkers and managers was found to have a statistically significant relashionship with age, work experience and type of employment contract (P-value<0.05). Given that perceived social support from coworkers and managers fell in the medium range in the present study, managers should make efforts to foster a greater social support in the workplace for their personnel and to create better relationships with them in the attempt to improve their performance in different domains. Due to the greater need of the less-experienced personnel for social support, managers are recommended to show their support through devising bonus schemes, providing emotional support and establishing a better relationship with their personnel.

The present study was conducted to examine the risk factors associated with hand activity and to determine their cumulative effect on the development of upper extremity musculoskeletal disorders. The present clinical trial was conducted on 24 men and 6 women employed at a tea factory in Fuman in northern Iran. The human body map was used to assess the prevalence of musculoskeletal disorders and the HAL-TLV method was used for determining the risk levels. All the tests were analyzed at a significance level below 0.05. The Wilcoxon test was used to measure the likelihood of developing musculoskeletal disorders. The Kappa test was used to compare changes occurring in the HAL-TLV results before and after the intervention. The data obtained were then analyzed in SPSS-16. The results obtained through the HAL-TLV method showed that, for the right hand, 7 participants were at a risk level below 0.56 (the safe zone), 10 at the risk level between 0.56 and 0.78 (the caution zone) and 13 at the risk level above 0.78 (the danger zone) before the intervention however, after the intervention, 27 participants fell at the safe zone, 2 at the caution zone and only 1 at the danger zone. The results obtained for the left hand showed that, before the intervention, 5 workers were at the safe zone, 12 at the caution zone and 13 at the danger zone after the intervention, however, 28 workers were at the safe zone, 1 at the caution zone and only 1 at the danger zone. The assessment of the risk factors associated with job-related musculoskeletal disorders and the design and implementation of technical, administrative and educational interventions can help reduce the prevalence of these disorders.

In developing countries, a high prevalence of musculoskeletal disorders has been reported among drivers. However, there are a few researches in this area among suburban bus drivers. This study aimed to determine the prevalence of musculoskeletal pains in suburban bus drivers in Zanjan.: This cross-sectional study has been verified by Ethics Committee of Zanjan University of Medical Sciences. Nordic questionnaire of musculoskeletal disorders and demographic questionnaire in relation to the the individual characteristics were filled for all of suburban bus drivers in Zanjan (89 individuals) in the spassenger terminals of this city. Data analysis was conducted using SPSS version 11.. The highest prevalence of musculoskeletal disorders in the participants for the last 12 months was observed in the low back (47.2%), neck (38.2%), shoulders and knees (27%) hip and thigh(16.9%), upper back (15.7%), foot and ankle (12.4%), wrist and hand (9.1%) and elbow (7.9%), respectively. Variables such as daily exercise, smoking, age and work experience showed a significant relationship with pain in various parts of the body within the last 12 months and 7 days (pvalue<0.05). However, the variables have no significant relationship between the variables and preventing normal work during the last 12 months. The results of this study showed a considerable prevalence of musculoskeletal disorders in the suburban bus drivers. Despite of the efforts undertaken to control the vibration of driver's seat vibration and provide an ergonomic work station for drivers, the lumbar and cervical pains are still common among them.