Biological exposure indices of occupational exposure to benzene: A systematic review.

The current study aimed to systematically review the studies concerning the biological monitoring of benzene exposure in occupational settings. A systematic literature review was conducted in Scopus, EMBASE, Web of Science, and Medline from 1985 through July 2021. We included peer-reviewed original articles that investigated the association between occupational exposure to benzene and biological monitoring. We identified 4786 unique citations, of which 64 cross-sectional, one case-control, and one cohort study met our inclusion criteria. The most studied biomarkers were urinary trans-trans muconic acid, S- phenyl mercapturic acid, and urinary benzene, respectively. We found the airborne concentration of benzene as a key indicator for choosing a suitable biomarker. We suggest considering urinary benzene at low (0.5-5.0 TLV), urinary SPMA and TTMA at medium (5.0-25 and 25-50 TLV, respectively), and urinary phenol and hydroquinone and catechol at very high concentrations (500 and 1000 TLV ≤, respectively). Genetic polymorphism of glutathione S-transferase and oral intake of sorbic acid have confounding effects on the level of U-SPMA and U-TTMA, respectively. The airborne concentration, smoking habit, oral consumption of sorbic acid, and genetic polymorphism of workers should be considered in order to choose the appropriate indicator for biological monitoring of benzene exposure.

Dynamic risk assessment of storage tank using consequence modeling and fuzzy Bayesian network.

Accidents in process industries cause irreparable economic, human, financial and environmental losses annually. Accident assessment and analysis using modern risk assessment methods is a necessity for preventing these accidents. This study was conducted with the aim of Dynamic risk assessment of tank storage using modern methods and comparing them with traditional method. In this study, bow tie (BT) method was used to analyze the Leakage event and its consequences and model the cause of the outcome, and the Bayesian network method was used to update the probability rate of the consequences. Then, four release scenarios were used. Possible selection and release outcome were modeled using version 5.4 of ALOHA software. Finally, according to the degree of reproducibility of possible consequences and risk number modeling for the four scenarios were estimated. The results of modeling the cause and effect showed that 50 Basic events are effective in chemical leakage and Pool fire is the most probable consequence due to chemical leakage in both BT and Bayesian network (BN) models. Also, the modeling results showed that Leakage 50 mm diameter has the highest Emission rate (80 kg/min) and Leakage of 1 mm have the lowest emission rate. The results of risk assessment showed that the estimated risk number in both models is in the unacceptable range. In this study, an integrated approach including BT, Fuzzy Bayesian networks and consequence modeling was used to estimate the risk in tank storage. The use of these three approaches makes the results of risk assessment more objective than conventional methods. The results of outcome modeling can be used as a guide in adopting accident prevention and emergency preparedness approaches.

An ergonomic intervention to relieve musculoskeletal symptoms of assembly line workers at an electronic parts manufacturer in Iran.

BACKGROUND: Prolonged, awkward postures among assembly line workers can lead to work-related musculoskeletal disorders (WMSDs). OBJECTIVE: This study determined the prevalence of WMSDs and ergonomic risk factors among assembly line workers at an electronic parts manufacturer, and introduced a low-cost ergonomic intervention. METHODS: Data were gathered by means of a questionnaire. The Rapid Upper Limb Assessment (RULA) technique was used to determine ergonomic risk factors. A low-cost intervention, designed to improve working postures was introduced. RESULTS: Most musculoskeletal symptoms were associated with the lower back (73.6%), wrist/ hands (71.7%), and neck (67.9%). Most (80%) of the working postures analyzed using the RULA were at action levels 3 or 4. CONCLUSIONS: The ergonomic intervention resulted in a significant reduction in posture scores for the neck and trunk. This indicated that the intervention helped to improve workplace ergonomics.

A comparative study on the function and structure of medical development education office in world's top universities.

PURPOSE: It is essential to adjust the responsibilities and function of medical education offices (MEOs) in regard to the current societal requirements. Therefore, it is a good idea to learn lessons from the experiences about the establishment and function of these offices around the world. The aim of the present study was to carry out a comparative study to investigate the function and structure of MEOs at some of the medical universities from America, Europe, and Asia. SUBJECTS AND METHODS: This is a comparative, descriptive study that was conducted in 2015. Eleven offices around the world (in America, Europe, and Asia) were selected for the study. Expert group discussion and literature review were used in order to select research sample. The data were gathered using self-constructed checklists. Content and face validity of the checklist was assessed by gathering feedback from experts. The Kappa coefficient was used to determine the inter-rater reliability. RESULTS: All the 11 offices in our study (100%) dealt with the issues of faculty development and research and scholarship activities. Only one out of the 11 offices (27%) dealt with the issues of society and patient education. Five out of the 11 offices (36%) dealt with the continuing medical education and continuing professional development. Consultation services are provided at seven of the 11 offices (64%). CONCLUSIONS: This study revealed both commonalities and differences in the function and structure of MEO among the 11 offices we examined. Based on this study, effective goals and strategies for MEO can be recommended.

Association between psychosocial, organizational and personal factors and prevalence of musculoskeletal disorders in office workers.

The purpose of this study was to investigate the relationship between organizational and personal (individual) factors with the prevalence of musculoskeletal disorders (MSDs) in office workers of the Iranian Gas Transmission Company. The participants rated two questionnaires - the standardized Nordic Musculoskeletal Questionnaire to measure the prevalence of MSDs, and the Veterans Healthcare Administration All Employee Survey questionnaire (2004 version) - to measure psychosocial, organizational and individual aspects of job satisfaction and workplace climate. The highest prevalence of MSDs was found in the lower back (49.7%) and neck (49.0%) regions. Results of the logistic regression models showed that some psychosocial and organizational factors and also some individual factors were associated with prevalence of MSDs (p < 0.05).These findings illustrate the need to consider all elements of the work system as a whole in future studies and in organizational planning.

Health consequences of shift-work: the case of iranian hospital security personnel.

BACKGROUND: Shift-work, which is an ergonomics issue in workplaces, can negatively affect workers. The security personnel of medical centers in Iran have multiple responsibilities and consequently are exposed to such unwanted situations as observing patients, disputing with patient's attendants, unwanted shift schedules, and being away from family for long periods. OBJECTIVE: This study assessed health problems of Iranian hospital security personnel (shift-worker personnel) using the Survey of Shift-workers (SOS) questionnaire (Persian version). METHODS: This cross-sectional study was conducted in seven medical centers (4 hospitals and 3 clinics). A total of 416 workers were surveyed: shift-workers (exposed group) (n=209) and non-shift-workers (unexposed group) (n=207). RESULTS: The prevalence of adverse health effects was higher in shift-workers than day-workers. The level of education and mean Body Mass Index (BMI) in shift-workers were significantly higher compared with day-workers. The prevalence of gastrointestinal disorders, cardiovascular and psychological problems were also significantly higher in shift-workers compared with day-workers. CONCLUSIONS: Overall, the prevalence of health problems among the security personnel of medical centers was high. Hence, it is recommended that personnel be put under periodic monitoring and receive medical counseling and treatment if there is any disorder.

Effects of physical and personal risk factors on sick leave due to musculoskeletal disorders.

The purpose of this study was to investigate the effects of physical and personal risk factors on sick leave due to musculoskeletal disorders in an Iranian car company. In this cross-sectional study, 234 workers participated and all of them had sick leave due to musculoskeletal disorders in the past year. A physical risk factor checklist and personal information questionnaire were used as data-gathering tools. There was no significant relationship between physical risk factors and sick leave (p > .05). Cigarette smoking (p = .045), body mass index >30 (p = .046) and age (p = .044) showed a significant relationship with sick leave. Workers with lumbar deviation of 20°-60° (OR 1.10) and >60° (OR 1.11) were at greater risk. The ratios for workers with repetitive work (OR 1.30) and workers with force exertion (OR 1.36) were greater than for other workers. Taking preventive actions to improve the ergonomic working conditions of assembly workers and their lifestyle seems crucial.

Manual material handling assessment among workers of Iranian casting workshops.

Manual material handling (MMH) tasks can be found in most workplaces and they may constitute a risk factor for work-related musculoskeletal disorders (WMSDs). This study was conducted to determine the prevalence of WMSDs and to compare MMH loads with the acceptable weight and force limits among Iranian casting workers. Data were collected from 50 workers of casting workshops who performed MMH tasks. The Nordic musculoskeletal disorders questionnaire and the Snook tables were used as tools for data collection. Hand/wrist symptoms were the most prevalent problems among the workers (84%). The results of the Snook tables showed that the loads in lifting (84%), lowering (86%), carrying (66%), pushing with initial (43%) and sustained force (59%), and pulling tasks with initial (48%) and sustained force (93%) exceeded recommended limits. WMSDs occurred in high rates among the workers and, thus, ergonomics interventions should focus on decreasing WMSDs and redesigning MMH tasks.

Noise annoyance due to construction worksites.

BACKGROUND: Noise pollution can contribute to adverse health effects in humans. Noise annoyance and related problems, caused by noise emission during the progress of building construction, have become increasingly important. These problems can influence the exposed workers, as well as vicinity residents. The goal of the present study was to assess the noise annoyance due to noise from construction worksites among residents of Hamadan City (west of Iran). METHODS: In this cross-sectional study, 20 construction worksites and 140 near vicinity residents were selected. The main sources of construction worksite noise were diesel power generators, cutting and welding processes, heavy machinery (such as trucks) and transport of materials. Ambient noise levels were measured using a calibrated sound level meter, at each home of the residents included in the study. A noise annoyance questionnaire was employed for annoyance assessment. RESULTS: The majority of subjects had very high annoyance (87.1%). The mean and SD of ambient levels were 74.57±7.12 dB (A) which exceeded the acceptable recommended level for residential areas. The most common problems among the participants were disturbance in sleep, difficulty in reading and distraction. Results showed significant relationship between noise annoyance and some factors including residing which floors had highest annoyance (F=13.22, P<0.001) and ambient noise (F=11.313, P<0.001). CONCLUSIONS: High levels of noise annoyance among near vicinity residents who are affected by construction activities. This means that construction activities and other noise related sources should be regarded as the major source of ambient noise leading to noise annoyance.