مجله بهداشت و ایمنی کار
سال یازدهم شماره 3 (پاییز 1400)

The acoustic performance of natural fiber adsorbents has been investigated in numerous studies. A part of these materials show a poor adsorption within the frequency range of less than 1000 Hz. In the present study, attempts were made to investigate the effect of layout sequence of double-layered composites consisting of natural and synthetic fibers on improving the acoustic adsorption coefficient of natural fiber in the low-frequency range (63 to 1000 Hz) using the numerical finite element method.

In this study, the finite element method and the Johnson-Champoux-Allard model in COMSOL software version 5.3a were used to investigate the acoustic performance of the double-layered composites consisting of natural and synthetic adsorbents. The acoustic absorbers under study included date palm fiber, polyurethane foam and cellular rubber. Each double-layered composite included a date palm fiber with 10mm in thickness and a synthetic adsorbent (polyurethane foam or cellular rubber) with 10mm in thickness. In sum, four double-layered composite structures with different layouts of adsorbents in each structure were studied.

The location of natural fiber can play a critical role in the acoustic performance of the double-layered composite structures such that comparing the studied double-layered composites revealed that when the natural fiber was the first layer exposed to the normal sound in the double-layered composites with 20mm in thickness, the trend of acoustic performance was approximately the same as the single-layered composite of natural fiber with 20mm in thickness; but in the composite structures, when the synthetic adsorbent was the first layer exposed to the sound, the trend of acoustic absorption was improved.

On the basis of the results, the double-layered composite structure with a higher-density and lower-porosity upper layer showed a better acoustic absorption trend than the single-layered composite including the natural adsorbent.

As an important problem, occupational procrastination is associated with organizational efficiency. Alhough this problem has received lots of attention from researchers, scant research has been conducted on the role of psychological hardiness and marital conflict in Shahrekord university staff. The main purpose of the present research was to predict occupational procrastination based on psychological hardiness and marital conflict in Shahrekord university staff.

This was a descriptive-analytical cross-sectional study. The research population consisted of Shahrekord university staff in 2017. The research sample (n=168) was selected using a convenience sampling method. The tools implemented were Occupational Procrastination Scale (Saffarinia and Amirkhani, 2011), Lang and Goulet Hardiness Scale (2003), and Marital Conflicts Questionnaire of Barati and Sanaei (2006). The obtained data was analyzed using descriptive statistics (mean and standard deviation), Pearson correlation tests, and multiple linear regression analysis.

The results of Pearson correlation showed that the relationships between psychological hardiness and occupational procrastination (r = -0.316, P <0.001), and marital conflict and occupational procrastination (r = 0.511, P<0.001) were significant. The results of multiple linear regression showed that marital conflict (B = 0.347, P<0.001) was predictive of occupational procrastination and explained 27.8% of the variance of occupational procrastination in Shahrekord university staff.

The obtained results showed that the occupational procrastination in Shahrekord university staff can be predicted through marital conflict. Therefore, this variable is recommended to be considered in investigating procrastination in Shahrekord university staff.

Musculoskeletal disorders (MSDs) are prevalent in work settings and are associated with high rate of prevalence and costs. Musculoskeletal conditions have multifaceted nature, and occupational factors play an important role in their development. The aim of this study was to identify the risk factors of work-related musculoskeletal disorders in the working population in Iran during 2000 to 2015.

Using the appropriate search terms, articles published in the journals, student thesis, and those presented at the conferences were searched through authentic English databases (Google Scholar, Scopus, PubMed) and Farsi ones (Magiran, SID, IranMedex, Irandoc). Following removal of duplicate citations and irrelevant studies, the full texts of the remaining publications were prepared and assessed for more detail.

Perceived discomfort in low back region obtained the highest score in workers of industrial, administrative, service, and agricultural settings. However, in the handicraft and educational groups, the highest percentage of discomfort was belonged to neck (66.7%). Findings showed that the most commonly used techniques for evaluation of musculoskeletal disorders and risk factors were, respectively, Nordic questionnaire (NMQ) (76%) and REBA (13.9%). Moreover, all identified risk factors were classified into eleven groups including: biomechanical, work environment design, tools, equipment, temporal aspects of job design, job content, organizational aspects, economic and financial issues, social aspects, individual characteristics, and training.

Overall, a wide range of risk factors reported in the previous studies were categorized in the present review. The results are suggested to be considered by managers and decision makers as a framework to take measures for controlling musculoskeletal disorders to accomplish the goal of ergonomics, which is productivity and well-being.

Comprehensive and reliable performance evaluation of organizations has always been one of the main concerns of stakeholders and managers of organizations. Performance evaluation can raise awareness of the progress made in improving the performance of any organizations, especially in the field of health, safety, and environment (HSE) and thus, create the necessary motivation and opportunity to improve the quality of HSE performance. National quality awards and excellence approaches emphasizes the fact that survival in global competition requires improving the performance of organizations on a global scale. The EFQM enterprise excellence model, as a comprehensive tool with a comprehensive approach to all aspects of organizations, helps managers to understand their organization well.

This study was conducted in Tehran Industrial Group in 2018, during which the performance of this industrial group in the design and construction of one of the dams in the south of the country was evaluated and analyzed. The data collection tool was a standard self-assessment questionnaire based on the EFQM enterprise excellence model, the validity and reliability of which was tested by Cronbach’s alpha coefficient at 0.971.

In terms of “enablers” criteria, the leadership dimension, with a score of 76.36, obtained the best percentage of scores, while the processes criterion with a score of 72.04 had the lowest percentage of scores. This dimension, along with staff, resources, and partnership dimensions, needs to be improved. In the field of “results” criteria, the key performance results with 79.77 points had the best percentage and the customer result dimension with a score of 69.13 had the lowest, indicating that the organization should improve these sectors.

The results indicated the suitable status of the organization in terms of the criteria of excellence model. The results of this model are generally used for systematic analysis of the organization in order to achieve a comprehensive view of the organization and its challenges.

Phytoremediation is one of the available techniques for removing the volatile organic compound from the air. Benzene and toluene are volatile organic compounds that exist in many occupational environments. Plants are able to reduce benzene and toluene in the air and the use of plants is a simple and consistent solution for the nature to reduce these compositions in the air and improve the air quality of work environments. The phytoremediation potential of Dannae racemosa and Hedera helix were evaluated for remediation of benzene and toluene in air.

Dannae racemosa and Hedera helix  were exposed to exposed benzene(250ppm) and toluene(250ppm) each time alone in a chamber and to examine the decrease amount of benzene and toluene during 6 days. Then plants were exposed to 250ppm and 250ppm of benzene three times with a rest day and the processes of reduction were investigated.

Dannae racemosa was able to remove all of benzene and toluene concentrations from the air after 6 days. Hedera helix was able to reduce all of benzene and toluene concentration from the air after 6 and 5 days, respectively. The differences in Benzene and toluene remediation were assessed between the first and the third subsequent exposure and the results showed that the reduction rate increased for Dannae racemosa.

It can be concluded that the Dannae racemosa and Hedera helix could be used for benzene and toluene phytoremediation.

Long-term exposure to hand-arm vibration causes musculoskeletal disorders mainly in hand and shoulder. The purpose of this study was to determine the effect of sport and using anti-vibration gloves on the grip strength of workers exposed to the hand-arm vibration.

In this descriptive-interventionist study, 41workers working in one of the Isfahan metal industries were studied. Data were collected by the demographic questionnaire, hand-arm vibration acceleration measurement was performed based on the ISO 5349 standard and grip strength was measured using the dynamometer device model Jamar. The investigations were performed on 3 groups including sporting moves, using of anti-vibration gloves and combination of sporting move and using of gloves. Twenty workers were selected as control group without exposure to any hand-arm vibration. Data were analyzed by the SPSS-21 software.

Workers’ grip strength difference was significant before and after vibration (PValue<0.001) and grip strength had significant and inverse relation with vibration (PValue<0.001, R= -0.411). Grip strength was higher in the group that used anti-vibration gloves accompanied with the sporting moves compared to before the intervention and significant relation was observed (PValue<0.001).

Vibration affects decreasing in grip strength and grip strength itself can be used as a screening measure for those workers exposed to the risk and diseases related to the vibration. Regular sporting moves and using anti-vibration gloves are effective on improvement of workers’ grip strength and preventing vibration-induced complications.

Accidents caused by children’s play equipment are considered a serious threat to children’s health. The aim of this study was to design slide, swing and see-saw based on national standards and children’s anthropometric data.

The present study is an applied research, in which the design of children’s play equipment, including slides, swing and see-saw was done according to national standards No. 6436-2, 6436-3 and 6436-6, as well as measuring the anthropometric dimensions. All anthropometric data of 385 children aged 2 to 12 years were measured and equipment design was performed using Minitab software.

In the national standards No. 6436-2, 6436-3 and 6436-6, the size of more dimensions required for the design of the slides, swing, and see-saw is not stated. In the present study, the ergonomic and standard design of these types of equipment is shown. Comparison of designed see-saw with see-saw available in parks showed that the length and width of the see-saw should be 0.37 and 0.25 meters, respectively. In the current study, however,  they were 0.24 and 0.35 meters, respectively. Also, the height, width and depth of the swing chair should be 0.2, 0.35 and 0.37 meters, while their actual size in the studied parks was 0.25, 0.42 and 0.31 meters, respectively.

The result of this study is helpful for standard and ergonomic designing of children’s play equipment and is very useful for urban planning. This study emphasizes the revision of national standards.

The development and implementation of effective safety educational program for minimizing hazards in a farm, is the most important activity that can be done to improve safety level there. This program, however, requires to needs assessment process. So, the present study was designed to analyze of the educational needs of farmers in the field of agricultural occupational health.

This quantitative study was conducted with a survey method. Statistical population consisted of farmers in Mahidasht County, Kermanshah Province, Iran (N =213), where 140 farmers was selected as sample by simple random sampling method and base on Krejcie & Morgan table. Research instrument was research made questionnaire that its validity confirmed by a panel of experts and the reliability was confirmed through a pilot study and calculation of Cronbach’s alpha coefficient. SPSS/16 software was used for data analysis.

Findings showed that educations in the field of occupational health were done neither sufficient nor according to the principles. Educational needs identified in the area included exposure to noise, exposure to dust, ergonomic issues, compliance with hygiene and protection principles in spraying, individual protection in working with tractors and other machinery.

Dangers of farming in one hand and the lack of appropriate education and  the farmers’ dissatisfaction in the other hand, has highlighted the necessity of implementing correct eductional programs according to needs assessment principles in Mahidasht County. In this regard, considering the knowledge and occupational health behaviors of the studied farmers, they need to receive education in most areas of health, among which, environmental hazards (sun and noise, dust on farms), ergonomic issues, proper and safe use of chemical input and adherence to safety principles in working with agricultural machinery are considered priorities.

One of the most important factors affecting quality of work-life (QWL) is the workload in the form of mental and physical. The increased workload may reduce the level of performance of workers. Therefore, the present study aimed to evaluate the relation of the mental and physicalworkload with the QWLof workers in the foundry industry.

This cross-sectional study was conducted on 218 male workers in a foundry industry and the work units with high work stress were selected. The NASA-TLX, physical load and the Walton questionnaires were used to collect and evaluate the workload and the QWL.The SPSS software was used for data analysis.

It was clarified that there was a significant inverse relationship between QWL with physical load (P = 0.001) and mental workload (P = 0.01). The comparison of mean QWL between different groups of demographic variables showed that the only significant relationship was between different age groups and QWL (P = 0.003). Finally, it was found that the variables of physical load, mental workload and age had a significant simultaneous effect on the mean score of QWL (P<0.05).

The findings showed that there was a significant relationship between QWL and mental and physical workloads.

Considering the importance of identifying and tracing primary sources of Covid-19 crisis in infection control, this study was carried out with the aim of identifying the occupational tasks effective in transmitting Covid-19 in the event of death of a female staff in medical record unit in Shafa Takestan Hospital (Qazvin Province).

This case study was performed on the death of a 26-year-old married woman working in the medical records department of Shafa Takestan Hospital in March 2019. After identifying and completing the tasks, hazards analysis was performed and finally, various tasks and amount of the Covid-19 sources were determined.

Covid-19 risk sources are classified into three groups of human resources with 51 cases (38.06%), office tools and equipment with 46 cases (34.33%) and paper with 37 cases (27.61%). Four tasks were identified as major tasks with a 59.90% of the total number of COVID-19 risk sources. In this study, two critical tasks were determined with the titles of “reply to requests of forensic medicine and insurance” and “reviewing patients’ surgical reports” that contained a total of 39.06% of the Covid-19 sources.

The results showed that the human resources in two major tasks were the most critical sources of Covid-19. So, the control of these critical tasks is of special importance. The results also showed that it is necessary to transfer the special and unusual tasks to the time after the crisis, in order to reduce the sources of Covid-19 contamination.

These days, there is a consensus that emotional intelligence plays an important role in the success of individuals in different areas of life. Persons with higher emotional intelligence had lower stress in dealing with demands and pressures in the workplace. The purpose of this study was to use artificial neural network to predict job stress and to compare the performance of this model with the multivariate regression model.

In order to do that, 892 participants were selected randomly in different job categories. Then, 15 dimensions of Bar-On questionnaire, 10 job categories, age and education were considered as input variables and 7 dimensions of health and safety executive HSE were determined as output variables in models.

The results revealed that an artificial neural network with hyperbolic tangent and sigmoid transfer functions respectively in hidden and output layers with 375 hidden neurons had significantly better performance than multivariate regression. So that, correlation of predicted values and job stress were only between 0.192-0.364 in regression model, but neural network had at least correlation 0.527 in all dimensions of job stress.

In predicting job stress using emotional intelligence, artificial neural network method was much better than multivariate regression model.

The carpet industry is one of the most important handicrafts in Iran. This industry is one of the most difficult and harmful professions, in which the employees are often working in a workplace with non-ergonomic, unsafe, and unhealthy conditions. The present study aimed to address the modeling of the individual, job characteristics, and workplace conditions with the general health of carpet weavers through an ergonomic approach.

The current study was a descriptive-analytic survey. The study population was female workers, who have had a minimum of one-year work experience and working in the workshops located in Meshginshahr city villages. The data collection tool was a combination questionnaire including, Goldberg’s questionnaire (GHQ-28), NIOSH questionnaire (disease history section), and questions about workplace conditions. The obtained data were entered into SPSS-17 software and analyzed statistically using statistical modeling based on the general linear model, multivariate and other statistical tests.

Unpleasant condition was observed among the 37.4% of the examined, in terms of general health. Logistic regression modeling was used to investigate the internal and external factors of carpet weavers with their general health status. According to the model, general health has a significant relationship (p<0.05) with most of the internal factors such as age, marital status, history of disease, etc. However, there was no significant relationship with the workplace conditions.

According to the results of this study, it can be concluded that demographic and job variables are of the most important factors affecting the general health of carpet weavers. Although in the model, the workplace conditions did not show any significant relationship with the components of general health, interpreting these findings requires more studies. More studies are required objectively to identify the effect causes of the general health of carpet weavers (especially workplace conditions).