Journal of Health and Safety at Work

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Introduction: Lead exposure is considered as a global health problem. The irreparable harmful effects of this heavy metal on human have been proven in various studies. Comparing to general population, workers in related industries are more exposed to lead. Several studies have investigated lead occupational exposure and its biological evaluation in Iran; however there is no overall estimate. Thus, the present study was conducted to determine the occupational exposure to lead and its biological evaluation in Iranian workers, using systematic review and meta-analysis.

Material and Method: This study was carried out based on information obtained from databases including Magiran, Iranmedex, SID, Medlib, Trials Register, Scopus, Pubmed, Science Direct, Cochran, Embase, Medline, Web of Science, Springer, Online Library Wiley, and Google Scholar from 1991 to 2016, using standard key words. All of the reviewed papers which met the inclusion criteria have been evaluated. Data combination was performed according to Random Effects Model using Stata software version 11.1.

Result: In the 34 qualified studies, the mean blood lead level (BLL) concentration in Iranian workers was estimated 42.8µg/dl (95% CI: 35.15-50.49). The minimum and maximum BLL were belonged to west (28.348µg/dl) and center (45.928µg/dl) regions of Iran, respectively. Considering different occupations, the lowest mean value was reported in textile industry workers (12.3 µg/dl), while the highest value was for zinc-lead mine workers (72.6 µg/dl). Mean breathing air lead level of Iranian workers reported in 4 studies was estimated 0.23 mg/m3 (95% CI: 0.14-0.33).

Conclusion: According to the high concentration of BLL and breathing air, it is recommended to increase protective measures and frequent screening. Scheduled clinical and paraclinical examination should also be performed for workers.

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Introduction: Despite the ongoing efforts to reduce human errors in various systems, errors and unsafe behavior are the main cause of accidents in the workplace. Many studies have been conducted to identify and improve human error in recent years. The number of studies about the human error with the variety of topics has made it an overall overview difficult for researchers. Therefore, a systematic review of previous studies can be the best way to share useful findings and make a trend for the future research in the field of human error.

Material and Method: After a systematic search of valid databases, the analysis was focused on the title, publication year, journal title / Congress, city/region, the level of organization, job search, type of organization and the methods used. And articles were evaluated based encryption.

Result: Three groups of human error studies were identified. The first group studies in safety management, safety assessment, and safety planning have investigated the human error. The second group has examined the influence of individual characteristics such as behavior, cognition, and education on human error. The third group has focused on data arise from the previous accident to improve behavior and reduce human error. To make a better orientation for next studies two essential aspects included chronological analysis and thematic analysis was considered.

Conclusion: This study made an attempt to identify the gaps in the studies related to human error and afford some appropriate strategies.

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Introduction: Work-related musculoskeletal disorders (WMSDs) are any disorders or injuries to the musculoskeletal system due to working procedure or conditions. WMSDs is one of the main causes of occupational injuries and disability in advanced and developing countries. The present study was conducted to evaluate the prevalence of musculoskeletal disorders in drivers in order to achieve complete results with high statistical power, using meta-analysis method.  
Material and Methods: This study is a systematic review and meta-analysis. In this study, the articles extracted from national and international databases, including Scientific Information Database (SID), Science Direct, PubMed (using the word MESH), Pre Quest, Scopus, Google Scholar, Iran Medix, SID, and MedLib. The main keywords for the search were Prevalence، Musculoskeletal and Drivers. The time for selecting articles was from 2000 to 2017. Data were analyzed using meta-analysis (random effect model). I2 and Q indexes were used to calculate heterogeneity. All statistical analysis was performed using STATA 14 software.
Results: In this study, 22 articles were entered into the meta-analysis process. The sample size was 7706 people with mean of 350 people in each study. The prevalence of musculoskeletal disorders in different organs of drivers was as follows: 26.19% (CI: 38-14.30), 18.07% (CI: 25.99-10.16), and 5.75% (CI: 8.27-3.22) in neck, shoulder, wrist / hand, and elbow respectively. The highest prevalence was related to low back pain 41.63% (confindence Interval (CI): 33.09-50.17), and the lowest prevalence was related to elbow disorder 7.45% with (CI: 95.46-9.43).  The significance level was set at 0.05.
Conclusion: The results of this study show that the prevalence of pains in the back, neck, and shoulder are high among drivers. Also, due to the high prevalence of predicting the incidence of impaired driving. in order to control and reduce these disorders, appropriate design of seats and equipment of vehicles, conducting periodic examinations of drivers,performing proper exercise, and considering adequate rest time in working hours are recommended. Ergonomics and occupational health education programs are also recommended to reduce the risk of developing musculoskeletal disorders associated with driving.

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Introduction: Burnout dimensions include the emotional exhaustion (EE), depersonalization (DP) and personal accomplishment (PA).
Materials and Methods: The information was obtained from searching standard Persian and English keywords in accessible databases including: Scopus, Magiran, SID, Science Direct  and  PubMed from database commencement to April 2017. Data  Analysis was performed using Stata version 11.1., and p value was considered less than 0.05.
Results: In the systematic review 43 studies met the inclusion criteria, and 9456 people were evaluated. The prevalence of burnout was calculated in any of the three dimensions of burnout. The prevalence of the Emotional Exhaustion (EE) dimension of burnout was%36 (%95CI: 29-42), the Depersonalization (DP) dimension was%23 (%95CI: 18-29) and the Personal Accomplishment (PA) dimension was%46 (%95CI: 39-53). Based on the type of the job, the maximum prevalence of the EE, DP and PA dimensions was in librarians 67% (%95CI:40-93), university staff 51% (14-88) and dentists 72%(%95CI:65-79), respectively. Meta regression results showed that there was no significant relationship between the year of publication and the prevalence of burnout.
Conclusion: According to the prevalence of burnout in Iran and the high prevalence of the PA dimension, it is recommended to consider mediating strategies for reducing and controlling stressful occupational events and burnout in organizational schedule.

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Introduction: Assessing health, safety, and environment (HSE) performance based on up-to-date analytical models like resilience engineering, especially in automobile manufacturing companies, affected by the trilogy of HSE factors and functions, is of crucial importance. Therefore, this study was to review the factors effectively involved in HSE management performance assessment based on resilience engineering in automobile manufacturing industries.
Material and Methods: To collect and classify the data, many relevant articles and procedures published in journals or presented at seminars were researched and cited. In this study, reliable online databases, including Google Scholar, Web of Science, Scopus, and PubMed were searched to meet this purpose. Other databases in Farsi such as Magiran, CIVILICA, and Scientific Information Database (SID) were also employed. Accordingly, a total number of 211 articles were extracted and filtered in terms of content and topic by a team of four HSE senior experts, whereby irrelevant studies were deleted, the full text of each relevant article was more closely considered, and finally 18 studies were selected and thoroughly examined.
Results: The findings from these 18 articles revealed that the HSE would be influenced in various industries by factors such as organizational culture, learning and training, political-economic variables, workforce qualifications and skills, strategic and large-scale programs of organization plus its assets and financial resources. In automobile manufacturing industries as well, circumstances might emerge because of some extra-organizational threats and intra-organizational weaknesses, whereby the appearance of deficiencies in various processes and even the functions of the HSE as a whole would be impaired. Of the many external factors, one could mention economic sanctions, large-scale socioeconomic problems, and lack of materials and production equipment. The internal problems would also range from production reduction and cuts in budgets earmarked for different management departments to a rise in the number of accidents and diseases, soaring medical treatment costs, as well as growing expectations in employees, which together impact the HSE management performance.
Conclusion: Regarding the studies conducted on various models presented so far in the area of resilience, it was concluded that the HSE performance of organizations intended to prevent and control risk factors were by no means distinct from other management factors and strategic decision-making in an organization. Rather, the HSE indicators could be impacted by many extra- and intra-organizational factors. Based on the models surveyed, it would be essential to consider the concept of resilience in HSE management. The reason for this is that the idea of the HSE would appear to be an issue of less virtue and importance in various stages and situations in the lifecycle of an organization, which is not consistent with the HSE management system and does not keep pace with the influencing factors.

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Introduction: 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.
Material and Methods: 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.
Results: 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.
Conclusion: 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.

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Introduction: Numerous studies have been conducted on the development of modern insulators, including nano-insulators. However, a comprehensive study has yet to be performed to review and investigate the thermal properties of these insulators. Consequently, this study aimed to examine the effect of nanomaterials on thermal insulation function.
Material and Methods: In this review, articles were searched for in English databases (PubMed, Web of Science, and ScienceDirect), Persian databases (Magiran, SID), and Google Scholar. The keywords used in the search were Nano Material, Nano Insulation, Thermal Insulation, Thermal Insulator Stability, and Thermal Conductivity in both English and Persian.
Results: Of the 4068 studies identified through search databases, 15 were selected according to the entry criteria. Among the studies, the three types of silicone, composite, and aerogel insulation had the highest frequency (each 26.67%), and SiO2 nanoparticles were the most prevalent nanomaterial (26.67%). According to the studies, the type of nanomaterial used in insulation will improve its properties such as thermal resistance, mechanical strength, dielectric strength, tensile strength, elasticity, and hardness.
Conclusion: The results of this study showed that using nanotechnology could be an effective step in improving the properties of insulation materials, the most important of which is increased thermal resistance. Moreover, nanotechnology insulators can prevent thermal energy loss, reduce costs, and provide safety and comfort.

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Introduction: Studies have demonstrated that teaching carries a substantial burden of health risks. Prevalent health issues among teachers include asthma, respiratory diseases, musculoskeletal problems, and mental disorders. These problems can be attributed to the specific attributes of their work environment. Consequently, this study aims to investigate the correlation between air quality within educational establishments and the overall health of teachers.
Material and Methods: This systematic review aims to examine the impact of temperature, humidity, and ventilation rates within educational environments on teachers’ health status and thermal comfort. Relevant studies were searched for using the PubMed and Web of Science databases, employing keywords such as teacher, temperature, humidity, ventilation, school, classroom, health symptoms, and thermal comfort (2000-2022). The inclusion criterion was that articles examined teachers’ health and comfort with temperature, relative humidity, and ventilation of the educational place.
Results: Out of the 103 articles found in the initial search, 13 articles were finally reviewed. Six studies investigated the voice abnormalities of teachers due to various factors (including temperature, relative humidity, and the ventilation rate of the educational place) and found that these abnormalities were affected by these factors. Two studies explored the relationship between the prevalence and exacerbation of respiratory symptoms and quality parameters of the indoor environment of educational places. Additionally, five studies investigated the relationship of air quality parameters of educational places with common non-specific symptoms among teachers.
Conclusion: Teachers frequently experience symptoms such as voice disorders, respiratory difficulties, allergies, and other nonspecific ailments, which may be associated with the quality parameters of the indoor environment in educational settings. These parameters include temperature, humidity, and ventilation rate. Consequently, controlling and regulating these parameters within the recommended values can help prevent the onset or exacerbation of these symptoms.

 

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Introduction: Lung cancer is the second most common cancer in the world. Smoking occupational and environmental exposures are the most important causes of lung cancer. Cadmium is known as a human carcinogen due to its ability to increase lung cancer risk. This study estimates the general results of all studies on the relationship between cadmium and lung cancer.
Material and Methods: In the present study, studies that evaluated the relationship between cadmium and lung cancer until May 2022 were searched and retrieved. From the funnel plot to determine the existence of diffusion skew, from the statistical tests Chi-squared test (x2) and I2 to determine heterogeneity, from the meta-regression method to identify the root of heterogeneity, and from the sensitivity analysis approach to identify the effect of each study on the result, it was generally used. This study performed all analyses with Stata statistical software version 15.
Results: In this study, it was observed that the chance of developing lung cancer compared to the base group, in the people exposed to a higher dose than the base level of cadmium is equal to 1.31 (95% CI: 1.06-1.62; p-value = 0.024), which is statistically significant. Based on Egger’s test (p-value = 0.178) and Begg’s (p-value = 0.276), no diffusion bias was observed in this study.
Conclusion: ccording to the final results of this review research, exposure to cadmium leads to a 31% increase in lung cancer risk, which is statistically significant. Therefore, cadmium is a risk factor for lung cancer.