نشریه طب کار
سال دهم شماره 1 (پیاپی 30، بهار 1397)

Exposure to noise pollution in the workplace is one of the most common occupational hazards and causes hearing loss. One of the ways to control voice in the control industry is by audio absorbers. Nanoparticles can be used to composite materials. The purpose of this study was to design and construct acoustic panels based on gypsum, silicon oxide nanoparticles, hydrolyzed cotton and nanodye, as well as to compare the absorbance of sound by them at various frequencies.
In this study, the nanocomposite consisting of gypsum, hydrolyzed cotton, silica nanoparticles and nanodye was prepared by simple mixing and heat treatment, and then its sound absorption coefficient was investigated. The absorption coefficient was evaluated at frequencies of 250 to 5000 using static waves and in accordance with ISO 9803-1.
The results showed that the maximum difference of the absorption coefficient was 10% at 2500 Hz, and it was related to a sample consisting of gypsum, nano silica, hydolized cotton, and nanodye, compared to a pure plaster sample. The highest absorption coefficient (0.46) of the sample was from gypsum, nano silica and hydolized cotton at a frequency of 5000 Hz.
The results of this study showed that with increasing frequency, the absorption coefficient increased, but the absorption coefficient was decreased by adding nanoparticles and nanodye.

The aim of this study was to analyze the relationship between perceived organizational support with employee's organizational commitment and job satisfaction among employees of Company of Narin Tile in Yazd province.Research

In this research, research methodologies were Pearson and Path Analysis. Statistical population consisted of all employees of Narin Tile Company. Among employees, 150 were chosen by stratified random sampling. Organizational support and job satisfaction were done on samples. According to the type of variable, and measurement level of variables, we made benefits from Pearson and Path Analysis.

This research aimed to study the mediating effect of Job Satisfaction (JS) on the relationship between Organizational Citizenship Behavior (OCB) and Perceived Organizational Support (POS) of the employees of Narin Tile Company in Yazd, Iran.
Research

The (JS), (OCB), and (POS) questionnaires were administered to a sample of (n=200) participants; i.e., all employees of Narin Tile Company through stratified random sampling. Pearson Correlations and Path Analysis were used to test the hypothesized relationships.
Findings: Results indicate that job satisfaction (as mediator) had no significant effect on the relationship between Perceived organizational support and organizational citizenship behavior; however, perceived organizational support had a strong meaningful effect on both organizational citizenship behavior and job satisfaction variables. Moreover, there was a strong significant positive correlation between the variables payment, fringe benefits as well as social interaction and the variable perceived organizational support. The relationship between perceived organizational support and job satisfaction was (r=.19). Furthermore, findings demonstrate strong significant positive correlations between ‘altruism and conscience’ and ‘job satisfaction’ as well as between ‘fringe benefits, nature of work and social interactions’ and ‘Organizational Citizenship Behavior’.

The study showed that the perceived organizational support (POS) of the employees had a significant effect in changing and promoting organizational citizenship behavior (OCB) of the employees. Also, it could improve employees’ job efficiency and performance at work.

The Rapid Office Strain Assessment (ROSA) is one of the emerging posture assessment methods for the office workers. Limited studies have examined the validity of this method for the reliable assessment of the ergonomics risk factors among the office workers. The aim of this study was to investigating the relationship between the ROSA with anthropometric dimensions, knowledge and behavior of the office workers in an Oil and Gas Company in Iran.
This cross-sectional study was conducted in an oil company during 2016. In all 259 office employees, worked on the central headquarter and operational offices, completed the General Nordic Questionnaire, knowledge and behavior questionnaires. Then the Rapid Office Strain Assessment (ROSA) and anthropometric dimension measurement were conducted for the participants. Data analysis was conducted by using frequency, mean and standard deviation, compare mean and Pearson correlation tests by applying SPSS software (version 22).
The results showed that by increasing employees's ergonomic knowledge and behavior, the prevalence of musculoskeletal disorders decreased (P ROSA score along with other individual, workplace and work-related factors can be applied to assess the ergonomic risk factors in the office workplaces.

Traffic accidents are an indispensable part of driving. In Iran because of large number of traffic accidents, several studies performed on the association between traffic accident and various personal and environmental factors
This retrospective analytical study was performed during April till August 2016 on 569 drivers, at Yazd city. The participants were professional drivers of heavy vehicles which received their driving license after 1991. Dependent variable was time to first accident. Survival analysis was conducted to determine the effect of personality on the time to first accident. Cox regression and Kaplan-mires method were used to test the hypothesis.Data analysis was performed on SPSS version 20.
Kaplan mires curves show that the risk of accident is higher for those with type A personality. However, there was no significant difference in occurrence of accident for these personality types (p= 0.379).

Wefound that risk of incidence of accident for those with type A personality is higher than type B. It implies that it should be considered for further medical and annual checking of drivers.

Exposure to chloride acid in industrial units can be associated with risks to the human respiratory system. The aim of this study was to investigate the respiratory symptoms and pulmonary dysfunction caused by exposure to chloride in acid washing unit of a steel industry.
This cross-sectional study was a descriptive-analytic study performed in a single acid washing unit in 2017. The exposed group included 45 male workers and a reference group of 41 unexposed employees from official employees. A questionnaire was used to collect personal and occupational data and a pulmonary function test was conducted in collaboration with a physician specializing in medicine to determine the pulmonary capacity of workers. Pulmonary function parameters included FVC, FEV1 and FEV1 / FVC. T-test and chi-square were used to describe and analyze the data in SPSS. The significance level in this study was determined equal to 0.05.
The results showed that all parameters of lung function in exposed subjects were lower than the reference group and this difference was statistically significant for FVC and FEV1 parameters (P 0.05). Based on the results of the regression model, exposures to hydrochloric acid increased the chance of these injuries by up to 7.4 times.
The findings of this study showed that exposure to hydrochloric acid alone could increase the risk of respiratory tract damage and pulmonary function disorders. Therefore, risk management should be considered in the face of this combination.

work-related musculoskeletal complications are one of the causes of disability and risk factors such as manual handling and repetitive work can cause or exacerbate these disorders. Considering the fact that in the industry, people with a wide range of risk factors for these disorders and high mental health are facing, this study was designed to investigate the position of work posture and mental load and their relationship with the operating personnel of Sarcheshmeh copper.
In this descriptive cross-sectional study, 220 individuals were selected randomly from a population of 800 people based on the demographic distribution of the units and the field study of the working areas. Data were collected using demographic, Nordic and NASA mental workload index and QEC software. SPSS software was used to analyze the data.
In this industry, due to the nature of work, the prevalence of musculoskeletal disorders was high in at least one region of the subjects. The prevalence of these disorders was related to the area of rest and back (38.6%) and back (38.2%) and The least of them was one or two females (2.3%) and there was a significant relationship between the mean total burden of mental health and the risk level and prevalence of disorders (p Due to the high risk of the occurrence and prevalence of musculoskeletal disorders and its relation with individual characteristics such as age and work experience and mental labor, it is necessary to control and reduce these disorders and the level of risk by implementing engineering controls such as mechanical appliances and tools. They stepped up and, with interventions such as a job rotation program, with the age and work experience of individuals, they were employed in jobs with different mental and physical needs that involve various muscle groups

Background and purpose: Particulate matter air pollution is one of the most important risk factors for cardiovascular and respiratory diseases. By increasing the number of tile and ceramic industries in the two past decades, workers in these industries exposed to pathogenic respirable particulate matter pollutants. Therefore, this study aimed to assess respiratory exposure to airborne particles in a tile and ceramic factory was done.

In This observational study, sampling from Respiratory zone of 93 workers in a tile and ceramic industry for both respirable and inhalable particles were performed. Sampling of inhalable particle based on NIOSH_0500 protocol and respirable particles based on NIOSH_0600 was conducted. Data were analyzed by SPSS 22 software.

92.47 percent of Workers were exposed to respirable particles less than TLV and 39.8 percent of them were exposed to inhalable particles more than TLV. The maximum concentration of respirable particles 13.04 mg/m3 and inhalable particles 84.88 mg/m3 in respectively reported for crusher unit. The lowest concentration of respirable (0.41 mg/m3) and inhalable (min =1.74 mg/m3) particles were observed in coating line workers division.

Since the workers are exposed to concentrations more than threshold limit value of respirable particles, and especially inhalable particles in some units, appropriate control measures must be considered to prevent possible consequences.

Nurses have a key role in health care organizations. Addressing factors affecting the nurses’ job performance is critical to success of health providing systems. The aim of this study is investigating the effect of individual factors on nurse's performance.
575 employed nurses in Tehran University of Medical Sciences’ elected hospitals were entered in this cross-sectional study in 2016. Multi-stages cluster sampling used for gathering information for available nurses. Demographic questionnaire and nurse performance checklist were used. Validity and reliability of tools were approved in previous studies.
Mean and standard deviation of total job performance scores were 217/44 and 31/25 respectively. 45% of the nurses entered in the study had an unacceptable level of performance. Among the seven areas examined in the job performance, working styles and general performance had acquired the most and the least mean score respectively. Also results showed that nurses with less weekly working hours had better performance (P-value: 0.008) and nurses with higher education level had very positive and meaningful better job performance (P-value: The results of present study showed that education level of nurses and their weekly work hours had an impact on their job performance. So it’s necessary to select nurses with high level of education and set their weekly work hours less, in parts of the hospital where job performance of nurses is more sensitive.