مجله بهداشت و ایمنی کار
سال دوازدهم شماره 1 (بهار 1401)

Prevention of heat-related diseases requires the participation of the workers. For this reason, the aim of this study was the development and validation of the tools for evaluating awareness and practice related to heat stress among the workers of warm workplaces.

The various items and factors related to the awareness and practice of the workers were identified by the literature review. Then, several questions for evaluating these items were designed. In the next step, the reliability and validity of the questionnaires were appraised using calculating the content validity ratio (CVR) and content validity index (CVI), and Cronbach’s alpha coefficient, respectively. After that, these questionnaires were completed by 2338 employees of six industries in various regions of Iran. Finally, collected data were analyzed using SPSS software.

In total, 77 questions, including 53 questions on awareness and 24 questions on practice in six groups of water and beverages, food, snacks and additives, heat exchange, thermal strain risk factors, clothing and heat protection equipment, and heat-related disorders and body reactions, were designed. The values of content validity index (CVI) of remained questions in the questionnaires of awareness and practice were equal to 0.954 and 0.824, respectively. The values of Cronbach’s alpha coefficients of these questionnaires were calculated by 0.755 and 0.716, respectively. The values of the chi-square divided by degrees of freedom (CMIN/DF) and root mean square error of approximation (RMSEA) in the construction of the awareness questionnaire were computed as 4.58 and 0.079, respectively. These values in the construction of the practice questionnaire were calculated by 2.33 and 0.084, respectively.

The results showed that the designed questionnaires had appropriate reliability and validity and could be used to evaluate the awareness and practice in warm workplaces.

One of the most important complications of exposure to noises is changes in the gene expression patterns. Irreversible damage to the inner ear, such as noise-induced hearing loss (NIHL), is caused by tissue damage and changes in the gene expressions in the auditory system. Changes in the GJB2 gene expression pattern lead to autosomal deafness at different loci. The present study aims to evaluate the GJB2 gene expression in cochlear tissue exposed to white noise.

In this study, ten male Westar rats were divided into two experimental (W1, W2) groups of six rats and a control (normal) group of four rats. Two experimental groups were exposed to constant white noise in the frequency range of 100-20000 Hz and the sound pressure level of 118-120 dB. In order to study the histology and gene expression, after a cochlea biopsy, the histological tests, RNA extraction, cDNA synthesis, and qRT-PCR analysis were performed.

The results showed that the transcript level of GJB2 was significantly decreased in both experimental groups W1 and W2 by 0.02 and 0.12-fold, respectively (p <0.05). Also, the results of the histological study showed that cochlear tissue was more seriously damaged in the W1 group than W2.

It can be concluded that a significant reduction in the GJB2 gene expression and irrevocable damage to auditory nerve ganglion and Reissner membrane (vestibular membrane) caused changes in the gene expression patterns in cochlear tissue and developed the risk of non-syndromic sensorineural hearing.

Maintaining and improving organizational safety requires a strong safety culture. Following the occurrence of occupational incidents, proper registration, reporting, and investigation is a key requirement for safety culture to provide an appropriate learning culture. As a result, this study was carried out to assess the culture of occupational incident registration, reporting, and investigation in the province of west Azarbaijan’s industries.

In this cross-sectional study, data on the culture of registration, reporting, and investigating occupational incident were collected using a 68-item questionnaire. A total of 420 employees from a number of construction and mine companies, as well as hospitals participated in this study.

The results of study showed that the average total score for the culture of registration, reporting, and investigating occupational incidents was 3.08 (±0.38), with the factor of corrective action had the highest 3.17 (±0.72) and the reasons for lack of reporting had the lowest 2.90 (±0.54) scores. There was also a significant relationship between the average score of the culture of registration, reporting, and investigating occupational incidents with education, industries, and companies. Employees who attended training courses had a lower mean score for the culture of occupational incident’ registration, reporting, and investigation than those who did not take training courses. The mean score of the culture of registration, reporting, and investigating occupational incidents of the employees who had experienced an occupational accident was lower than those who had not experience occupational accidents in the past.

The findings of this study revealed that corrective actions is necessary after the occurrence of occupational incidents. Attending training courses and having an occupational accident experience had no positive impact on promoting culture of registration, reporting, and investigating occupational incidents.

Nowadays, excessive computer use in the workplace has raised concerns about the health status of VDT workers, particularly complaints about eye discomforts. Due to the importance of the eyelids and eye closure parameters on eye health during computer works and the direct effect of monitor height on these parameters, this study was aimed to examine the effect of different monitor heights adjustment on the eye indicators and eye discomfort among participants.

In this study, any changes in the eye indicators including blink rate, the eye blink opening and closing time, the blink opening rate in three different monitor heights (standard, low, and high) were examined among 11 participants. The blink rate and the eye blink opening and closing time were measured and evaluated using videotaping and analyzing by an image processing software, developed in this study. Participants were also asked to complete a questionnaire for eye fatigue assessment due to daily computer uses.

Results showed that the highest rate of eye blink was at the standard height of the monitor, and this rate was significantly different at three different heights of monitors (high, standard, and low) (p<0.05). The lowest blink rate was observed at low and high heights with an average of 7.3 and 7.8 and the highest blink rate at standard height with an average of 8.9 blink per minute, respectively. Meanwhile, image processing and analyzing of eye surface showed, in average, 16% decrease in the opening rate of the eye surface by decreasing the height of the monitor, and 15% increase by increasing it, relative to the standard mode of monitor.

To protect users from computer-related eye strain, it is recommended to correct monitors height to the standard height along with typing and data entry training for keyboarding skill development and minimizing working times as a result. What is more, a proper work-rest schedule when working with computer can be considered as an effective countermeasure to prevent from eye strain.

The noise could affect some aspects of human health, including the cognitive performance. In addition to sound pressure level and exposure time, the psychoacoustic features of noise may cause destructive effects on humans. A few recent studies have been conducted on effect of sound quality on cognitive performance. This study aims to find the noise loudness and sharpness levels as the most destructive effects on human cognitive performance.

This was a cross-sectional study on 10 male students of Tehran University of Medical Sciences. The Noises were generated in two channels that the left channel produced the pink noise as a background noise. The pink noise loudness and sharpness were 19.7 sone and 2.49 acum, respectively. The right channel generated noises with different loudness and sharpness levels the noise loudness ranged from 8.87 to 67.9 sone and the noise sharpness ranged from 1.07 to 6.4 acum. Finally, ten noises with different loudness and sharpness were applied. The students were exposed to ten different types of noise and a silent condition. The Mathematical Problem Solving Task (MPST) test was performed to assess cognitive performance. The reaction time and the accuracy rate were measured after 5 minutes of noise exposure. Data were analyzed by SPSS (ver. 22). P< 0.05 was considered as significant level.

The mean reaction time and the mean accuracy rate increased with the sharpness level.  However, alteration in the loudness and sharpness levels had no significant effect on the speed and accuracy of students. Performance speed increased in noise 3 with the highest loudness (L=67.9, SH=1.07) in comparison with the silent condition (p-value=0.05). The mean accuracy rate in exposure to the noise 9 reduced in comparison with silence (p-value=0.04)

Different levels of psychoacoustic features had no significant effect on the cognitive performance parameters. Although, the accuracy rate and the reaction time decreased in noises 9, the sharpest noise, and 3, the loudest noise, in comparison to the silence, respectively.

Permit-to-work system (PTW) system is a documented system to control the activities with inherent risks and probability of accident occurrence. To inform the performance and efficiency of a system, it must be periodically monitored and evaluated, and the permit to work system is no exception of this principle. The aim of the present study was to design and develop software for evaluating the performance of the PTW system.

This study included two main stages. At the first stage, based on the literature review and interview to the academic and industrial experts, the PTW questionnaire for evaluating the performance was created. The second stage involved the design and implementation of an initial version of a software and the investigation of its usability. Designing the software was performed using system development life cycle (SDLC). The usability of this software was evaluated by Think -Aloud method. Finally, the users’ satisfaction was measured using the Questionnaire for User Interface Satisfaction (QUIS) questionnaire.

Based on the results of the QUIS questionnaire, the overall satisfaction of the designed software was 7.71 in a nine-point scale. The scores of the software performance, display and user interface features, software terminology and information, learning, and overall system capabilities were obtained as 7.58, 7.37, 7.75, 8.11, and 7.74, respectively. Also, the outputs of the excel and SPSS software were in accordance with those of designed software, which show the reliability of the outputs of the designed software.

The designed software facilitate the proper and systematic analysis and it is flexible to evaluate the PTW system and represent types of reports in predefined structures that can be a useful tool in the process industries such as oil and petrochemical refineries and other similar industries.

Nosocomial infection (NI) is an infection occurring in a patient after 48 hours of hospitalization or up to 72 hours after discharge from the hospital, which was not present or incubating at the time of admission.  Hospital accreditation standards have a significant impact on the prevention and control of NI. Nevertheless, Iran’s hospital accreditation standards face challenges. The aim of this study was to compare the accreditation standards of NI prevention and control in Iran and leading countries.

This research was conducted using the comparative review method in 2020. Hospital infection prevention and control (IPC) standards of Iran Hospital Accreditation Program was compared with those of international accreditation programs in the United States, Canada and Australia. Thematic analysis method was used to analyze the qualitative data.

Iran and the United States had the highest share of nosocomial IPC standards. The Iranian Hospital IPC standards approximately comply with 62.1%, 46.6% and 49.9% of Hospital IPC standards of the United States, Canada and Australia, respectively. A hospital infection management system including constructs of NI leadership and management, NI planning, NI education, employee management, patient management, resource management, process management and outcomes is necessary for IPC. Iran Hospital Accreditation Program places great emphasis on process and resource management and less importance to leadership and management, planning, employee management, patient management and outcomes.

The Iranian Hospital Accreditation Program is progressing. However, its IPC standards need to be reviewed and updated. Using a systems approach including structures, processes and results in the development of hospital accreditation standards, leads to the optimal use of hospital resources and achieving better results.

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.

Over recent years, various programs have been conducted to reduce noise, indicating the increasing concerns of society over noise pollution. This study has been performed to enhance the performance of parallel barriers on two sides of a highway considering the surrounding buildings.

The 2D boundary element simulation method was employed to predict the noise reduction in barriers. Regarding the effect of buildings and water canals, various kinds of models were investigated to compare the effectiveness of different boundary barriers in real conditions from a listener’s perspective.

The use of a single YA model could improve the performance of parallel barriers by 3.5 dB compared to that of a TS model. Moreover, by using a pair of barriers, no significant change was observed in the performance of the second barrier. However, by using parallel barriers along the surrounding buildings, the TD model improved the efficiency by 3 dB compared to the TS model. The rise in the frequency resulted in remarkable adverse effects on the barrier performance, such that the surrounding buildings at a distance of 8 m had a negative effect on the performance of the parallel barriers by almost 8.34 dB.

In general, by ignoring the buildings, the use of a pair of TZ barriers showed a higher performance. Meanwhile, by considering the buildings in the design model, the TD model was found to be optimum. Therefore, it can be concluded that choosing an ideal barrier only based on the noise behind it cannot indicate its behavioral and acoustic characteristics in a real environment.

The formation and evolution of culture in organizations are related to the learning experiences of their members over time. In this regard, the present study was conducted to empirically investigate the correlation relationship between the Learning Organization (LO) and safety culture concepts in Iran’s nuclear and radiological industries.

A theoretical model concerning the connections between seven facets of LO and safety culture was proposed. It was then empirically tested with a structural equation modeling PLS analysis of a survey data set of 388 observations, collected from the radiation workers of 45 organizations in 4 Iranian industrial groups i.e. medical radiation, industrial radiography, nuclear installations, and radiological installations. Yang’s DLOQ questionnaire in 2004 and IAEA’s SCPQ-LH questionnaire in 2017 were used to measure LO and safety culture, respectively.

According to the findings of this study, being a LO could explain 52% of the variance in safety culture. Besides, it was observed that the strength of this relationship between four different subpopulations of Iran’s radiological and nuclear industries due to their different contexts, had significant differences and they vary from 34% for industrial radiography to 65% for nuclear installations.

The existence of LO conditions in the working environment is linked to high safety culture. Thus, the LO can be joined to the toolbox of consultants, managers, and other organizational developers attempting to advance the conditions for safety at work.

Job burnout is a kind of psychological exhaustion that is associated with psychological stress or job and workplace stress and can affect the general health of the individual.  Job burnout is more likely to occur in jobs offering health and social services. Considering the special problems of hospital staff due to high work sensitivity, this study was conducted to identify the relationship between job burnout and mental health among non-medical staff of general, specialty and sub-specialty hospitals affiliated to the Iranian oil industry.

This research is descriptive-analytical which is of correlation type. Cluster random sampling was used to select 251 non-medical staff members of Oil Company’s hospitals in Abadan, Ahwaz, Mahshahr and Tehran. The instruments used included demographic checklist, Goldberg General Health Questionnaire and Maslach Burnout Questionnaire. The data were analyzed by Spearman, Mann–Whitney U test and Kruskal-Wallis correlation test at the level of 0.05.

The findings showed that the mean and standard deviation of age of participants were 38.82±8.3. 49.5% of participants were female  The mean and standard deviation of mental health was 2.12 ± 0.405 and the mean and standard deviation of burnout was 28.4 ± 0.634. There is a meaningful and reverse relationship between burnout and mental health, mental health and emotional exhaustion and depersonalization and personal adequacy in non-medical staff in general, specialty and sub-specialty hospitals affiliated to the Iranian oil industry.

Based on the findings of the study, job burnout affects mental health. Burnout affects both male and female. The findings of this study can be used in planning preventive measures, and identifying groups which are exposed to risk in work environments.

The purpose of the current study was to predict the percentage of the sway index from the static balance point based on the anthropometric dimensions of construction workers.

This descriptive-analytical study was conducted on 114 construction workers. First, the construction workers were asked to complete the demographic questionnaire and the inclusion criteria were determined. Then, the anthropometric dimensions were measured. Afterward, the static balance of participants was assessed with their open eyes and standing position using a Stabilometer device. The obtained data were analyzed using Pearson correlation and multiple linear regression.

29.8% of construction workers were in weak and very weak classes in terms of static balance. The Pearson and spearman’s correlation coefficient showed a significant relationship between age, weight, and sway index of individuals. In addition, multiple linear regression showed that age, weight, and foot surface of construction workers can predict the percentage of the sway index from the static balance point among construction workers.

The results of the current study indicated that demographic information such as age, anthropometric parameters of weight, and foot surface are effective factors on static balance in a healthy construction workers’ community with a normal body mass index.

In process industries, some of the primary events may result in secondary events in an industrial unit called the domino effect. Since refinery storage tanks are always at risk of fire and explosion, quantitative risk assessment is important in determining the severity and outcome of an accident, taking into account the effects of dominoes on the main industry, neighbors, and society and can play an important role in risk management. Therefore, the purpose of this study was to quantitatively evaluate the risk of condensate storage tanks taking into account the domino effect.

The technique used in this study was Quantitative Risk Assessment (QRA), the analysis of the consequences of which was performed using PHAST (7.22) after setting goals, studying the process, identifying hazards and scenarios. Then, to determine the extent of the domino effects of the escalation vectors were matched against the threshold, and after screening, the overall vulnerability of the repositories for mapping individual risk levels was calculated.

In the leakage scenario, after considering the domino effects, the risk contour 10-4 to about 250 meters and the risk contour 10-5 to about 400 meters increased. Also in the catastrophic rupture scenario, the radius of risk contour of the 10-5 increased to100 m after considering the domino effects up to around damage tank.

As can be deduced from the results, using this method can give a clear picture of the consequences of chain events and the probability of damage to nearby employees, equipment and neighbors, which is very important in risk, emergency and crisis management.

Sleep deprivation is one of the factors affecting the physiological performance of athletes and laboratory evidence has suggested a link between sleep deprivation and decreased physical performance of athletes. The aim of this study was to determine the effect of sleep deprivation on objective and subjective physiological responses of student-athletes.

The research is experimental. Twenty male volunteer sports science students selected and examined in two conditions with simple random selection in counter balanced intra-group pattern. Participants examined at two controlled situation; 1) after twelve hours fasting and eight hours enough sleep, and 2) after twelve hours fasting and thirty hours quiet sleeplessness. Measurements of physiological variables including: blood pressure, heart rate, blood lactate, mental scale of pressure perception, VO2max and body temperature were examined with specialized tools. Variations in independent variable related to intervention were analyzed using t test in the significance level of P<0/05 and SPSS software.

Physiological responses of blood lactate (p = 0.002), heart rate (p = 0.01), ratings of perceived exertion (p = 0.002), time to exhaustion (p = 0.001), blood pressure (p = 0.01) =) and body temperature (p = 0.002), after deprivation of sleep to a debilitating activity in the post-test compared to the pre-test increased and the maximum oxygen consumption (p = 0.001) decreased significantly, which was also statistically significant. The findings of the present study showed that sleep deprivation can cause a significant change in the objective and subjective physiological responses of sports students.

According to the results of the present study, it was found that 30 hours of sleep deprivation caused significant changes in the objective and subjective physiological responses of athlete students. In a general conclusion, the findings of the present study showed that sleep deprivation should be mentioned as one of the potential limiting factors of physiological function.