rajabali hokmabadi

One of the important principles of workstation design is the anthropometric compatibility of the workstation with people. Designing workstations by the anthropometric characteristics of employees can prevent awkward working postures and reduce the risk of such disorders. The present study aimed at investigating the anthropometric compatibility of workstations among Female Tailors and its association with working postures.

This cross-sectional study was conducted in female tailors in north Khorasan province in 2021. Participants were randomy selected and invited to the study. Working postures were assessed in workstations using the NERPA technique. Anthropometric dimensions were measured by ISO 7250 and anthropometric compatibility with the workstation was investigated. Mann-Whitney, Chi-square and T-test were used when analyzing the data.

two hundered and ninty six tailors with a mean age of 26.5±12.7 years participated in this study. There was no significant association between posture scores and anthropometric conformity in the dimensions of chair back height, width, and depth. Anthropometric Compatibility with chair height and desk height is the only important factor of a workstation with a significant effect on people's posture (P<0.01). The final score of the NERPA method determined that 30 workstations (15%) had a low-risk level, and 166 stations (85%) had a high-risk level.

Anthropometric incompatibility with workstation generally deteriorated the working postures. However, anthropometric compatibility with seat-height and desk height were the ones with a significant association with working posture. Therefore, the seat height and desk heightshould be considered first for redesigning workstations.

Accidents may occur in all occupations. However, firefighting is considered as one of the most dangerous occupations considering firefighters’ perception of security, work-related injury rate, safety behaviors, attitudes and norms. Therefore, this study aims to investigate the correlation between the organizational safety climate and unsafe behaviors among firefighters.

This was a descriptive and survey research. The statistical population included all the managers and employees working in a fire department consisting of 16 fire stations in Tehran. A researcher-made checklist and an organizational safety climate questionnaire were used to assess the prevalence of unsafe behaviors and safety climate. The data were analyzed using SPSS 21.0 software.

The employees’ mean age, body mass index (BMI) and work, rest and exercise duration were 32.5±66.83 years old, 25.69±3.7, 9.2±14.1 h/d, 8.15±1.73 h/d and 5.44±4.46 h/w, respectively. Also, 66% of the employees were overweight and 29% had normal weight. Among the safety climate dimensions, the highest mean was related to management commitment to safety issues (33.7±62.68) and the lowest mean was related to priority over products (6.1±03.63). Unsafe behaviors were mostly associated with lack of using the breathing apparatus in small fires (91.9%) as well as personal protective equipment (PPE) (77.4%) in accidents and not performing operations with inappropriate physical condition (38.7%). The t-test results revealed a significant correlation between the safety climate and prevalence of unsafe behaviors (P≤0.05). Moreover, a significant correlation was observed between the employees’ knowledge, participation, attitudes and environmental safety (P≤0.05). However, no significant correlation was found between emergency preparedness, safety priority and ignoring risks.

Organizational safety climate could affect and predict the employees’ behaviors. Therefore, it is recommended that fire department managers develop a plan to achieve the required safety climate and improve the safety climate level.

Reliability is always of particular importance in system design and planning; thus, improving reliability is among the approaches for achieving a safe system. Simulation methods are widely used in system reliability assessment. Therefore, this study aims to assess the reliability of the City Gate Gas Station (CGS) using Monte Carlo Simulation (MCS).

This descriptive and analytical study was conducted in one of the CGSs of North Khorasan Province in 2021. The CGS process was carefully examined and its block diagram was plotted. Then, failure time data of CGS equipment were collected over 11 years and time between failures of subsystems was calculated. The failure probability distribution function of subsystems was determined using Easy Fit software and Kolmogorov-Smirnov test. Moreover, subsystems’ reliability was estimated by MCS. Finally, station reliability was calculated considering the series-parallel structure of the CGS.

The results revealed that the failure probability density distribution function of CGS subsystems was based on gamma and normal functions. The reliabilities of filtration, heater, pressure reduction system, and odorize were calculated as 0.97, 0.987, 0.98, and 0.992 respectively, and their failure rates were 0.000003477, 0.0000014937, 0.0000023062, and 0.0000009169 failures per hour respectively. The station reliability was calculated as 0.93.

The failure probability distribution function and reliability assessment of subsystems were determined by data modeling and MCS respectively. Filtration and pressure reduction systems had the highest failure rate and required a proper maintenance program.

Firefighting is one of the most dangerous jobs. Occupational stress is known as an effective factor in increasing the risk of mental and physical problems in the workplace. Therefore, the purpose of this study was to investigate the relationship between job stress and unsafe behavior of firefighting employees.

The present study was a descriptive-analytical type conducted in 2020 among the staff of one of the firefighters in Tehran. 62 people were selected as statistical samples using simple random sampling. In order to assess the prevalence of unsafe behavior and occupational stress, a researcher-made checklist and Health and Safety Executive (HSE) occupational stress questionnaire were used, respectively, and data analysis was performed using SPSS21 software and independent t-test and Pearson correlation tests.

The most unsafe behavior was related to not using the respiratory system in small fires. The lowest and highest levels of job stress related to the relationship between communication and demand were 8.83 and 22.58, respectively, and the total level of job stress was 107.29. No significant relationship was observed between unsafe behavior and job stress dimensions.

The average score of occupational stress was high in all the examined people. Failure to use pants and fire wear and failure to use the experiences of colleagues during fire and accident were a part of the unsafe behaviors of the fire department employees, so the management unit should adopt the necessary training and measures to correct these unsafe behaviors for the fire department employees.

Excessive working hours, insufficient rest, and irregular driver schedules are factors that could cause drowsiness in professional drivers; consequently, reducing the driver's ability and increasing the chance of road accidents. Therefore, the present study aimed to Investigate the relation between drivers working and resting hours with the occurrence of road accidents among heavy vehicle drivers.

This analytical and cross-sectional research was performed in 2018 and 200 heavy vehicle drivers in Tehran province, Iran, were evaluated. A standard driver safety questionnaire was used to collect data. Data analysis was performed using SPSS software (version 21).

The mean age of drivers, driving hours per day, continuous driving hours, and rest hours per day were calculated as 47.5 ± 9.05 years, 10.66 ± 2.52, 5.82 ± 1.87, and 8.7 ± 1.13, respectively. The average number of road quasi-accidents and accidents for drivers in the last five years was 4.26 ± 2.29 and 1.1 ± 1.2, respectively. The number of accidents was significantly associated with age, drowsiness, safety and health education, driving hours, the number of continuous driving hours, and the number of rest hours. No significant association was found between the number of accidents and smoking.

Behaviors such as long driving hours, long continuous driving hours, short rest hours, and drowsiness are among the causes of heavy vehicle drivers’ accidents in the country. Planning with the approach of informing, and raising awareness and skills of drivers to change their harmful habits and high-risk driving behaviors could significantly reduce road accidents.

Human factor analysis has been identified as the most common cause of accidents in natural gas transportation and distribution facilities. The occurrence of accidents at these systems, especially gas reduction stations located in residential and industrial areas, has had catastrophic consequences. Therefore, this study aimed at analyzing critical tasks and human error assessment using the system for predictive error analysis and reduction (SPEAR) method and providing the appropriate framework for error management in the operation and maintenance of city gate stations.

This descriptive cross-sectional study was conducted using the SPEAR framework and safety critical task analysis guideline to evaluate errors in gas pressure reduction stations. First, critical tasks were screened and evaluated, followed by performing task analysis by the hierarchical task analysis and detecting performance-influencing factors (PIF). Then, human errors were predicted and assessed based on the predictive human error analysis. Finally, error management was developed at three process, equipment, and training improvement levels.

In general, out of 23 operations and 164 sub-tasks, 12 critical tasks were identified based on the results. Criticality level percentages were about 67% high risk, 25% moderate, and 8% low risk. In addition, 134 errors were identified which were mostly related to action (42.53%) and checking (39.55%) errors, respectively. Eventually, communication, retrieval, and selection errors were 8.96, 5.22, and 3.74%, respectively.

The results revealed that action and checking errors had the highest percentages. This method can be applied to appropriate the systems approach to error reduction using the PIF assessment output. The privilege affecting factors include preparing standard operation procedures, implementing a comprehensive training program, and controlling environmental hazards.

Gas pressure reduction stations play a key role in the timely and safe supply of natural gas (NG) to residential, commercial, and industrial customers. Accordingly, system reliability analysis should be performed to prevent potential failures and establish resilient operations. This research proposed a reliability assessment approach to natural gas pressure-reducing stations using historical data, statistical analysis, and Monte Carlo simulation (MCS). Historical data are employed to establish the probability distributions of the system and subsystems in gas stations. Then the Kolmogorov-Smirnov test is conducted to assess the goodness-of-fit for the developed distributions. Bayesian network (BN) is utilized to develop a system failure causality model. Finally, we performed MCS to precisely predict the failure rate and reliability of stations and all subsystems, such as the regulator, separator and dry gas filters, shut-off valves, and regulator. This research provided numerical findings on the reliability indicators of pressure reduction stations which can be used to improve system performance and, subsequently, the resilience of NG pipelines.

Improving the system's reliability is one way to achieve a secure system. City Gas Station (CGS) has a key role in the timely and safe supply of Natural gas (NG) to residential, commercial, and industrial customers. With complexities inherent in systems, having a proper and all-embracing model of the entirety of a system is not readily possible. The continuous-time Markov chain (CTMC) model is regarded as a great help in communicating, comparing, and integrating partial system models. In this study, we have exploited CTMC for reliability analysis in CGS stations. The CTMC model can solve both time-dependent and stationary state probabilities. Therefore, it can potentially develop the state enumeration method into a sequential one. Implementing this procedure leads to identifying critical components and failure probability, eventually enhancing the station's reliability. Additionally, some suggestions are presented for optimizing the performance of the station.

The hazard and operability study (HAZOP) method is a risk assessment method based on engineering systems used for qualitative analysis or quantitative evaluation. It is mainly used to discover potential hazards and operational difficulties in the design and qualitative stages of chemical systems. The study aims to apply the HAZOP method in process and safety operations at gas depressurization station.

This descriptive study was performed at CGS station. The station was divided into four principal nodes including: filter, heater, regulator, and odorize part. Required information for HAZOP worksheets were gathered by operational procedures, daily reports and interviews with engineers and operators working at the station. To determine the severity of consequences and probability of occurrence of scenarios that were predicted based on the risk matrix, the amount of risk was specified and the necessary suggestions were made in this regard.

According to this study, the operational indicators in the pressure reducing station process included pressure, flow, level and temperature. 22 main deviations and 50 causes of failures were identified. 5 deviations (23%) were in the low risk range (green area) and 17 (77%) were in the medium risk range (yellow area).

  Causes and effects of deviations in operational parameters at four nodes in gas depressurization station were identified by HAZOP. Preventive actions were emphasized, such as consistent inspection of pipelines, preventive and timely maintenance and preparing a well-scheduled plan for inspecting the equipment in terms of corrosion, inspection, and design revision.

Failure modes and effects analysis (FMEA) method is used in industries to identify, assess and prioritize risks. Multi-criteria decision-making methods (MCDM) select the best option from different criteria. Therefore, this study aims to identify, assess and prioritize risks using FMEA based on SWARA-VIKOR multi-criteria decision-making methods in a gas pressure reduction station.

In this descriptive and analytical study, stepwise weight assessment ratio analysis (SWARA) and decision-making optimization and compromise solution (VIKOR) methods were used to rank the risks of failure modes identified in FMEA. SWARA method was employed to determine the severity, probability and discovery weights, and VIKOR technique was applied to rank the failure modes of the system equipment. Finally, an operational example of the pressure reduction station was presented to show the application and feasibility of the proposed model. A comparative study was conducted to confirm the practicality and effectiveness of the proposed model.

In total, 35 main failure modes were identified in the pressure reduction station. Failure of regulator sleeve and safety valve and regulator diaphragm rupture were assigned the first, second and third ranks of risk priority, respectively. The sensitivity analysis results showed the proposed approach had desirable stability and only the failure mode of increasing the heater flame temperature was very sensitive to changes in the weight of the criteria. Results of ranking the failure modes of the station indicated there were many changes in the ranking of failure modes based on the proposed approach.

The proposed approach could provide more reasonable and accurate results for ranking risks because the criteria were weighed step by step based on the experts’ opinion.

In recent years, the rapid growth of technology and the use of computers have affected almost all workstations, and musculoskeletal disorders are very common among computer users. Therefore, this study aimed to evaluate the ergonomic status and prevalence of musculoskeletal disorders in computer users.

This descriptive-analytical study was conducted on 100 Bank staff in Bojnurd, Iran. The Rapid Office Strain Assessment (ROSA) method and Nordic standard questionnaire were used to evaluate the ergonomic status, and determine the prevalence of musculoskeletal disorders, respectively. The data were analyzed in SPSS software (version22), through the Chi-square test, one-way ANOVA, and descriptive statistics.

The mean±SD age and work experience of users were determined at 34±6.9 and 15.1±0.7 years, respectively. A significant relationship was observed between gender and pain in the back (P=0.037), wrist/hand (P=0.032), knee (P=0.024), and upper back (P=0.054).The most common skeletal-muscular disorders in people were observed in the waist, neck, and upper back areas in the body, respectively. The mean±SD final ROSA score of the chair, phone-monitor, and mouse-keyboard was estimated at 3.7±1, 3.6±1.1, and 3.65±1.2, respectively, and the mean±SD of the final ROSA score was 4.4±0.9. Based on the ROSA method, 35 workstations had a risk score≥5, indicating the need for further evaluation and immediate corrections.

According to the results of this study, it was found that work-environment factors that affect skeletal-muscular disorders include chair, mouse-keyboard, and phone-monitor, in the order of significance. Therefore, most of these injuries can be prevented by correcting the ergonomics of chairs and the proper placement of the mouse-keyboard.

There is evidence that exposure to heat stress over time may lead to chronic kidney disease. This study aimed to summarize the evidence on the effects of heat stress on renal function among individuals exposed to occupational heat stress.

In this systematic review, all papers on the effect of heat stress on kidney function among workers at any workplace and heat level were included. Reviews, case reports, conference proceedings, letters, editorials, abstracts without full text, in-vitro, and animal studies were excluded. Furthermore, studies conducted on children, general populations, and hospitalized patients, as well as those not measuring heat stress, were also excluded. Medline, Scopus, ISI, and Embase databases were searched from 1st January 1991 to 19th October 2021. Search criteria were prepared by combining an 'exposed population' AND 'exposure' AND 'outcome' keywords. Quality assessment was done using the National Institutes of Health Quality Assessment tool.

A total of 24 articles with 14,282 participants were considered for qualitative synthesis. Although most papers indicated a positive association between heat stress and kidney dysfunction, especially regarding dehydration, the present study found heterogeneous evidence. Glomerular filtration rate, serum creatinine level, and albumin-to-creatinine ratio, due to occupational heat stress, were other markers mentioned in primary studies.

This review highlighted the impact of occupational heat stress on renal function. Among the markers investigated in this review, most studies reported a positive association between occupational heat stress and dehydration.

Sleep is one of the important physiologic needs in daily life cycle, and a part of quality of life. Sleep disorders are considered as one of the most common health problems in work communities that can affect physical, mental performance and ability to work. Therefore, this study aimed at investigating the relationship between sleep disorders and work ability in construction workers.

This study is descriptive-analytical and cross-sectional. Samples of 220 people were selected by random sampling method from construction workers and personnel. Data collection tools in this study included sleep quality questionnaire, insomnia severity questionnaire and work ability questionnaire. Data were analyzed using SPSS software (version 19) and, considering the objectives, descriptive statistics and analytical tests including paired t-test, Pearson’s correlation, Kruskal-Wallis, multiple linear regression and logistic regression were used.

Average age, body mass index, working hours and work experience were calculated as 34.2 ± 8.5 years old, 55.58 ± 2.78, 10.5 ± 1.25 hours and 12.7 ± 6.5 years, respectively. The mean indices of insomnia severity, Petersburg quality of sleep index and work ability were 6.6 ± 5.35, 4.95 ± 2.43 and 42.5 ± 5.13, respectively. The relationship between the work ability with sleep disorders was statistically significant. Variables of marital status, types of employment and smoking, independent of the variables of insomnia severity and sleep quality, significantly affected the work ability index, so that the R2 of these variables were 0.246 and 0.242 of the changes in work ability index, respectively.

Any disturbance in sleep and resting can cause poor sleep quality. As a result, it severely reduces the ability of employees to work. Therefore, it is suggested that, in order to increase the index of work ability and, thus, the efficiency of an organization, special attention be paid to sleep-resting programs of employees.

Covid-19 pandemic has imposed a significant effect on mental health of the health care workers. The present systematic review and meta-analysis aimed at determining the pooled prevalence of anxiety and depression among Iranian health care workers during the Covid-19 pandemic.

To conduct this systematic review and meta-analysis, Web of Science, Scopus, Medline (PubMed), Embase, SID, Magiran databases and Google Scholar search engine were investigated to find studies over the prevalence of anxiety and depression among health care workers during the Covid-19 pandemic from December 2019 to June 10, 2021. Quality of the primary studies was assessed using the Newcastle-Ottawa tool and the random effects model was applied to estimate the pooled prevalence. Furthermore, χ2 test and I2 index were used to evaluate the degree of heterogeneity among the studies. The pooled prevalence of anxiety and depression in different subgroups was reported based on the severity of anxiety and depression, assessment tools, and staff jobs.

Of 488 articles obtained as a result of the initial search, 10 related studies were identified and entered into the systematic review and meta-analysis. The pooled prevalence of anxiety was 42% (95% CI: 25-75) and the pooled prevalence of depression was 35% (95% CI: 19-55). The pooled prevalence of anxiety was 54% (95% CI: 39-70) in the occupational group of nurses and 29% (95% CI: 17-44) among all health care workers. The pooled prevalence of depression was 46% (95% CI: 30 to 63) and 17% (95% CI: 10 to 26) among nurses and all health workers, respectively.

According to the findings, a high prevalence of anxiety and depression was observed among the health care workers of Iran during the Covid-19 epidemic. The authorities are required to plan for preventive and therapeutic interventions to reduce the psychological burden of the epidemic.

Failure modes and effects analysis (FMEA) is a risk-management method used in industries promote the safety of processes and systems. Fuzzy multi-criteria decision methods are methods that choose the best option from several different criteria. The purpose of this article is to assess the risk using the FMEA method based on stepwise weight assessment ratio analysis (SWARA) - relative-entropy (RE) - VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) fuzzy multi-criteria decision-making (MCDM) methods in an urban gateway gas pressure reduction station.

In this descriptive-analytical study, SWARA fuzzy methods were used to determine the weight of risk factors, RE was used to weigh team members, and VIKOR was employed to rank failure modes, such that these modes were identified and evaluated based on the opinion of four experts with at least five years of experience. At the end, the sensitivity and comparative analysis of the proposed approach was performed.

Six failure modes were identified in the main equipment of Darveza Shahri gas pressure reduction station. The failure mode of the regulator, filter, and the odorize system ranked first, second, and third in terms of risk priority. The risk intensity index had a higher priority than other indices. Twelve sensitivity analysis tests were performed, and the failure mode of the regulator and the heater were the least and the most sensitive, respectively. Furthermore, the results of the sensitivity and comparative analysis supported the validity of the proposed approach.

According to the results of SWARA, RE and VIKOR fuzzy methods, the proposed approach eliminates the problem of the same weights of risk factors, the uncertainty in the data (experts' opinions) and the prioritization of failure modes, compared to the traditional FMEA method. It can also prioritize risks more effectively.

Road accidents, as the main causes of mortality and disability in the world, have been seriously endangering human health. Human factors are among the most significant causes of road accidents. This study aimed to investigate the association between high-risk behaviors among truck drivers with their fatigue and drowsiness in the occurrence of road accidents and near miss accidents.

This descriptive study was conducted recruiting 200 truck drivers in Tehran using two-stage cluster sampling method, in 2019. A standard driver safety questionnaire was used to collect data, with its reliability measured by the test-retest method. The Fisher's test, a chi-squared test, and the Pearson’s correlation were used to analyze the data.

The mean age of the drivers and the mean hour of driving were 47.5 ± 9.05 years and 10.66 ± 2.52 hours, respectively. In addition, the number of accidents had a significant association with the drivers' age, drowsiness, talking on the cell phone, texting, eating snacks, and driving hours. However, it had no significant relationship with drinking tea and smoking. Furthermore, the rate of road accidents had a significant correlation with the drivers' driving time and rest hours.

Behaviors and factors, such as talking on the cell phone, texting, eating snacks, long hours of driving per day, long hours of nonstop driving, low rest hours, and drowsiness were among the major causes of accidents among trucks drivers. In this regard, authorities are recommended to run educational courses to modify high-risk driving behaviors so as to reduce road accidents.

Job stress is one of the most common health-related problems all over the world, which is associated with many physical hazards. The aim of this study was to assess job stress in firefighters and to investigate its association with musculoskeletal disorders.

This work is a descriptive-analytical study and was conducted in one of the firefighting stations located in Tehran. HSE Job Stress Questionnaire and the Kernel Musculoskeletal Disorders Questionnaire were used to assess job stress and musculoskeletal disorders, respectively. Data analysis was performed using SPSS21 software. Ethical considerations were observed in all stages of the study.

Mean age of employees and their working time were 32.66 ± 5.83 years and 9.14 ± 2.1 hours per day, respectively. The lowest and highest levels of job stress were 8.83 and 22.58 and the amount of total job stress was equal to 107.29. Musculoskeletal disorders were very common among firefighters and were in the knee, shoulder, back and neck areas, respectively. Overall score of job stress and role dimensions, support of officials, support of colleagues, demand and change were significantly associated with musculoskeletal disorders.

Job stress and musculoskeletal disorders were very common among firefighters and a statistically significant relationship was observed between job stress and musculoskeletal disorders. Therefore, job stress may be a factor in the development of musculoskeletal disorders in firefighters, so a care system for firefighters is needed to reduce job stress and prevent musculoskeletal disorders.

Heat is one of the most important physical harmful factors in many work environments. Due to the nature of work, bakery activity is considered as one of the high-risk occupations in terms of heat stress. Therefore, the aim of this study was evaluated of heat exposure in bakery workers using WBGT, HSI and UTCI indices.

This study is a descriptive-analytical cross-sectional study that was conducted in bakeries in Bojnurd. In this study, heat stress was evaluated based on WBGT, HSI and UTCI indices. WBGT meters, thermometers and anemometers were used to measure the required parameters. Statistical analysis was performed by SPSS21 software.

The mean of WBGT, UTCI and HSI indices were 34.81  2.63, 37.02 3.54 and 64.65  24.23, respectively. The values of UTCI and WBGT indices except air velocity were significantly associated with all environmental parameters. There was a positive correlation between all physiological parameters and UTCI and WBGT indices. HSI index was significantly associated with oral temperature and mean skin temperature. There was a strong positive correlation between WBGT and UTCI and a weak positive correlation between HSI and WBGT and UTCI.

There was a correlation between UTCI and WBGT as well as environmental and physiological parameters and a strong correlation was observed between UTCI and WBGT. It seems that UTCI is also suitable for assessing occupational heat stress in indoor environments such as bakeries.

Working with a computer and workplace conditions expose people to risk factors of musculoskeletal disorders (MSDs). This study aimed to assess posture, examine MSDs, and determine, weigh and prioritize the risk factors among computer users by a neural network algorithm. 

This descriptive-analytical cross-sectional study was conducted in six phases on computer users in 2019. The status of MSDs was determined via Nordic musculoskeletal questionnaire (NMQ). The factors affecting these disorders were determined by the ROSA method, and then these factors were weighed by the neural network algorithm. The data were analyzed in IBM SPSS Modeler.

The mean age and work experience of the users were 34 ± 6.9 and 1.5 ± 0.7 years, respectively. Most of years were observed at the lower back, neck, and upper back, respectively. The final mean scores of the chair, telephone-monitor, and mouse-keyboard were 3.7 ± 1, 3.6 ± 1.1, and 3.65 ± 1.2, respectively and the final mean score of ROSA was 4.4 ± 0.9. The greatest correlation with the ROSA score was observed in chair (R2 = 0.46), followed by telephone-monitor (R2 = 0.43), and mouse-keyboard (R2 = 0.42). The highest predictor importance of the effective factors based on the neural network algorithm prioritization belonged to the chair (48%), followed by telephone-monitor (28%) and mouse-keyboard (24%). The accuracy of the neural network algorithm in examining the effect of factors on musculoskeletal disorders was 98% based on the ROSA score.

Factors affecting years due to working with computers are the chair, telephone-monitor, and mouse-keyboard, respectively, as prioritized by the neural network algorithm. These disorders can be prevented by ergonomic modification of users’ chairs and correct placement of the monitor and telephone.

Health care workers have direct contact with COVID-19 infected patients and healthy people, so ensuring the safety of health care workers is important not only to protect them against the coronavirus but also to prevent the spread of the coronavirus in the community. The aim of this review was to determine the risk factors of COVID-19 among health care workers.

In this systematic review, papers related to COVID-19 risk factors among health care workers were assessed. Search for papers was done with focusing on the risk factors of COVID-19 and healthcare professionals and combining appropriate keywords, without limiting the type of study and publishing year, in the scientific databases Pubmed, MEDLINE, Embase, Google Scholar and EBSCOHost.

Out of 1750 papers, after removing duplicate papers and reviewing title, abstract and full text, 15 papers remained for data extraction. According to these papers, the risk factors of COVID-19 among health care workers include exposure to infected people, lack of appropriate personal protective equipment, heavy workload, poor infection control and direct contact with contaminated surfaces, lack of hand hygiene and underlying disease (hypertension, diabetes, cardiovascular disease, chronic lung disease, and immunodeficiency).

In the COVID-19 pandemic, health care workers are exposed to the occupational risk of morbidity and mortality, so the development of rapid and sustainable measures for comprehensive protection of health care workers is needed.

Traffic accidents and casualties are one of the current challenges of human societies endangering human health and imposing a heavy economic burden on communities. It is of utmost importance to identify the psychological causes and factors affecting the occurrence or severity of traffic accidents. Therefore, the current study aimed to assess the effects of traffic behavior on the occurrence of accidents in Azarshahr, Iran, in 2019.

The present descriptive cross-sectional study was performed on 260 drivers in Azarshahr who were selected via simple randomization. The instrument used for data collection was the standard Driver Behaviour Questionnaire (DBQ). Data were analyzed in  SPSS software (version 18) using descriptive statistics and Pearsonchr('39')s correlation coefficient.  

The mean age of participants was 35.32± 9.59 years, driving history was 10.94±7.98 years, and daily driving time was 3.19±2.69 hours. The results of the present study suggested that slips had the largest share in the occurrence of accidents. The mean scores of slips, intentional violations, errors, and unintentional violations were obtained at 1.42, 1.18, 1.03, and 1.07, respectively. The number of accidents demonstrated a significant relationship with gender, age, education, type of vehicle, driving time, and place of residence (P<0.05).

As evidenced by the obtained results, some factors, such as gender, age, education, and driving time, play a significant role in the occurrence of accidents in Azarshahr. Therefore, it is necessary to hold workshops to modify driverschr('39') behaviors and attitudes.

Cement factory workers exposure to airborne particles containing crystalline silica in Portland cement chemical compound can caused pulmonary diseases, including silicosis and lung cancer. The aim of this study was to assess the risk of occupational exposure to respirable cement dust and crystalline silica in a cement factory in Khorasan Razavi province.

In this cross-sectional study conducted in 1397, the method presented by the Institute of Occupational Safety and Health of Singapore was used to assess the health risk of respirable cement and silica particles. Also, the standard method MDHS101 / 2 recommended by NIOSH was used to determine the concentration of respirable cement particles in the air of the workerschr('39') respiratory area and the X-ray powder diffraction method (XRD) was used to determine the concentration of inhalable crystalline silica particles. Stata software version 14 was used for statistical analysis of data.

This study showed that most of the workers employed in various worksites of the cement factory were exposed to respirable cement dust and crystalline silica particles higher than the OEL recommended by the Iranian TCOH and the TLV recommended by ACGIH. Exposure risk assessment in different parts of cement factory showed a low risk level for respirable particles of cement in the furnace and moderate for other sections. Also a high risk level for workers’ exposure to crystalline silica was found in the cement mill and very high level for workers in other sectors.

Employees who were working in this plant were exposed to moderate risk of cement respirable particles and high risk level of exposure to crystalline silica. Thus, the engineering control methods of exposure to respirable particles is suggested.

Perpetration of samples is one of the most important stages needed for trace residue analysis of biological specimens when human exposure assessment is required. The samples preparation process makes the analyte get more purified and enriched as well as more compatible to the analysis instrument systems. The present study has concentrated on a systematic review of different articles published regarding the sample preparation methodologies of human biological samples.

In this systematic review, all articles related to the development of sample preparation for trace residue analysis of heavy metals in occupational biological samples published in English during 2009-2019, were considered. To meet the desired objective of the current study and facilitate the  related articles on physiochemical sample preparation methods accessibility combined keywords of Mesh and non-Mesh, without any limitation in the type of studies, the Pubmed, Web of Science, and Scopus were considered to be searched. Noteworthy, in this study, only the articles related to the workers’ biological samples were reviewed.

Based on the obtained results, after reviewing of the keywords trough websites, 2964 articles were identified. Then, the redundant papers were removed and59 articles were remained, based on their titles and abstracts,. After detailed review of selected articles, regarding the study criteria, 8 articles were selected for the final systematic review.  Five articles out of 8, (62.5%) were allocated to the development of sample preparation for mercury in biological samples. It is worth mentioning that the majority of biological samples were regarded to the urine samples (75%) in the current study. Based on the obtained results, Solid Phase Extraction (SPE), applied in 37.5% of studies, was a popular method used in sample preparation.

The development of sample preparation approaches indicates a great promise for specified methods with low costs and less extraction time when separating different heavy metals from complex matrices. These sample preparation and preconcentration techniques ease the analyses processes and provide the quantitative recoveries, higher sensitivity, and lower detection limits.

Coronaviruses are important pathogens in humans and animals. In late 2019, a new coronavirus was identified as the cause of a group of pneumonia cases in Wuhan, Hubei Province, China. The disease spread rapidly, resulting in epidemics in China and reports of sporadic cases worldwide. In February 2020, the World Health Organization (WHO) identified COVID-19, which stands for Coronavirus 2019. The virus that causes COVID-19 has been identified as the Coronavirus virus, Severe acute respiratory syndrome 2 (SARS-CoV-2), formerly known as 2019-nCoV. Coronavirus disease 2019 (COVID-19) is a name for the disease, and the virus that causes it is known SARS-CoV-2. The very rapid spread of the COVID-19 in China and in many other countries has caused fear among people across the world. The novel coronavirus outbreak declared a Public Health Emergency of International Concern on 30 January 2020. Due to the fact that one of the ways of transmitting the coronavirus is through respiration, one of the most important ways to prevent coronavirus is to use personal protective equipment, including masks, so the knowledge around the use of masks by the general public prevention COVID-19 disease transmission is advancing rapidly. Policymakers require guidance on how to use masks and how to use them for people in the community to combat the COVID-19 disease pandemic. In this article, the relevant literature to inform multiple areas include transmission characteristics of COVID-19 disease, filtering characteristics and efficacy of masks and estimated population impacts of widespread community mask use were synthesized.

In this descriptive review study was examinesd all articles on mask wear and its effect on the prevention of transmission of pandemic diseases, including COVID-19 and influenza, which were published in Farsi and English. PubMed, Web of Science, Google Scholar, Scopus and Embase databases were used to search for articles, focusing on the use of masks and the prevention of COVID-19 disease, and combining appropriate keywords (Masks, SARS-CoV-2, COVID-19, Influenza, Epidemic, Prevention and Transmission) without restricting the type of study.

Corona virus size ranges from 80 to 160 nanometers, which can help in choosing the appropriate mask and respiratory protection. Anyone who comes in close contact (less than  of two meters away) with a person with respiratory symptoms (such as sneezing, coughing, etc.) is at risk for exposure to potentially infectious respiratory particles. A main route of transmission of COVID-19 disease is likely via small respiratory droplets, and is known to be transmissible from presymptomatic and asymptomatic individuals that come out in talking, coughing or sneezing. The most common droplet size is at least 5 to 10 micrometers. SARS-CoV-2 has a high transmission potential and its transmission rate to individuals is about 2.4. Disease spread was reduced by restrict contacts of infected individuals via physical distancing, contact tracing with appropriate quarantine and reduce the transmission probability percent act by wearing masks in public. The evidence indicates that mask wearing reduces the transmissibility per contact by reducing transmission of infected droplets. Public mask wearing is most effective at stopping spread of the virus when compliance is high.  Therefore, one of the most important ways to prevent the coronavirus is to use personal protective equipment, including masks. The standard masks recommended by reputable organizations are surgical masks and N95 masks. The use of cloth masks is recommended as a last resort, and it has been stated that these types of masks are not part of personal protective equipment. Especially in people who are part of the medical staff and do patient care work. Because of the ability of these masks to protect the person is unknown, and caution should be exercised when using these masks. Ideally, these masks should be used with a protective device that covers the entire front of the face (chin and underneath) and both sides of the face. The N95 mask (American standard; equivalent to FFP2 in Europe) is recommended as a mask for health care workers who perform clinical care for patients with COVID-19 disease. So that if these people use these masks well and according to the instructions, they will not have any problems during the epidemic. In this article, the use of surgical and clean masks by medical staff in medical centers to prevent Rhinovirus infection is recommended and similar studies show that fabric masks have less filtration to the rhinovirus. The results of the above study on the use or non-use of fabric masks in the community cannot be used to control the source of coronavirus, which is a seasonal coronavirus. Another point is that wearing a mask as a source control is largely a cessation of this process, as large droplets become smaller particles suspended in the air that can spread more into the air. Homemade masks have the ability to filter out the normal range of droplets, just as they are effective in blocking droplets and particles, meaning that these masks help keep the droplets from spreading in space. There is no RCT study to evaluate the effect of masks on social transmission during a coronary heart disease. While there is evidence of a flu outbreak, the current global epidemic is a unique challenge. According to a conservative assessment of COVID-19, the initial rate of proliferation is estimated at 2.4. If the mask is used and the efficiency of the mask is 50%, this amount will be reduced to 1.35.The spread of the disease. If the spread of the disease is completely stopped, the initial rate of proliferation will be less than one. As a result, the spread of the disease ends in the community. Wearing a mask may be critical to preventing a second wave of infection in the health care system - more research is needed.

A review of the use of masks in this article showed that proper use of masks at the community level has a significant impact on reducing the rate of disease transmission among people in the community. Non-medical masks use substances that prevent the release of droplets of the required size. Non-medical masks are very effective in reducing the transmission of influenza. The results show that non-medical masks are effective in small trials in blocking coronavirus transmission and in areas and periods when the use of masks was required and widely used; the transmission of the disease has decreased in the community. People are usually infected in the early period after infection, which usually has few or no symptoms during this period. It is also suggested that the general use of cloth masks is more effective than other health strategies, distance and patient diagnosis strategies in reducing the rate of disease transmission. It is suggested that government officials and relevant organizations strongly encourage the use of masks by the public and crowded environments as a requirement to reduce disease transmission. To reduce the transmission of respiratory viral disease, the following interventions should be preferred, preferably in combination:- Frequent washing with or without side disinfectants - Create a retainer such as using gloves, clothing and a mask equipped with a filter - Identify suspicious individuals by isolating possible cases However, it has been warned that long-term routine administration of some of the evaluated measures may be contagious without the threat of disease. Health officials need to provide specific guidelines for the production, use and disinfection or reuse of facial masks and to review their distribution on a regular basis so that they do not become deficient. According to the precautionary principle, the positive effect of wearing a public mask is "scientifically acceptable but unclear." While researchers may logically disagree about the degree of reduction and flexibility of the transfer rate, it seems that the relatively low benefits due to the exponential distribution of the transfer process can be collectively profitable. Models show that wearing public masks is most effective in preventing the spread of the virus when acceptance is high. This is the situation we see with vaccines.Therefore, the use of masks should be done extensively with confidence based on this principle in society. All countries suggest that masking is a low-risk but highly potentially positive action, so that many countries with a high prevalence of the disease have been able to reduce mortality with the widespread use of masks. It is recommended that governments apply the requirements for the use of masks, and that organizations that provide public services, such as public transport providers or stores, apply the rules: "Without masks, no services are provided." These rules should be accompanied by measures to ensure that people have access to masks, possibly without problems in the mechanisms of distribution and storage of masks, and to focus on the benefits of public health. Health officials also need to provide specific guidelines for the production, use and disinfection or reuse of face masks, and review their distribution on a regular basis to avoid deficiencies. Also, clear and applicable guidelines can help increase public acceptance of the use of masks at the community level and reduce communities to the goal of ultimately stopping the spread of COVID-19.

Lighting lessons is necessary for the occupational health students. Educational aids are essential in promotion of learning. This study aims to evaluate students’ learning in practical part of lighting lesson by using educational resources of lighting boards.

In a quasi-experimental study that was carried out on occupational health students of North Khorasan University of Medical Sciences. The samples were divided into case and control groups. Each group consists of 40 participants. The control group was trained in the traditional method and the case group was trained using the educational board. In addition to studentschr('39') feedback, studentschr('39') scores were also judged to assess learning. The scores in both groups were analyzed by SPSS 19 software.

25% (n = 20) of students were male and 75% (n = 60) were female. With the use of educational boards, learning speed, retention of skills, ease of understanding and motivation increased by 85%, 90%, 90% and 95%, respectively. The mean score was 17.75 ± 1.75 in case group and 15.5 ± 2.15 in control group. The mean difference in acquired scores was significant between the case and control groups.

The occupational health studentschr('39') learning improved with the use of educational boards. According to the results of the studentschr('39') comments, this tool can be used as a useful educational tool in presenting this lesson.