Journal of Health and Safety at Work

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Introduction: Occupational exposure to manganese can cause neurobehavioral symptoms. The aim of present study was to survey neurobehavioral symptoms of welders exposed to manganese- containing welding fumes and compare the frequency of these symptoms with unexposed group.

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Material and Method: Twenty seven of welders as exposed group, and 30 administrative workers as unexposed controls, were participated in this study. Neurobehavioral symptoms data were gathered using Q16 questionnaire. Manganese concentrations were determined according to the NIOSH 7300 method. After preparing of blood samples using microwave assisted acid digestion method, all samples were analyzed to determine manganese by graphite furnace- atomic absorption spectroscopy (GF-AAS).

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Result: The mean exposure to air manganese was 0.023± 0.012 mg/m3. Manganese concentrations in blood samples of welders (15.88± 7.11 µg/l) were significantly higher than unexposed workers (9.37± 8.70 µg/l), (P-V<0.05). The frequency of neurobehavioral symptoms of welders was significantly higher compared to unexposed workers (P-V<0.05). The correlation between neurobehavioral symptoms and blood manganese was significant for welders (P-V<0.05).

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Conclusion: Welders’ exposure to manganese and its potential health effects should be evaluated periodically and effective control measures should be applied in order to to prevent neurobehavioral symptoms.

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Introduction: In Iran country, small enterprise with less than 10 workers comprise about %90 of all industries and 80% of working population. Noise, higher than the permissible level is among the hazardous agents, workers in these plants facing with. The aim of this study was to investigate the correlation between screening estimation and noise measurement in small plants.

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Material and Method: This cross-sectional study was conducted in 51 plants with less than 5 workers. Noise screening was done using screening from. Next, noise level was measured in all the plants by TES-1358 sound level meter and regular grid method. Data were analyzed using chi-square test and linear regression in SPSS version 16.

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Result: The mean (SD) scores of sound pressure level and screening form were 86.5 dBA (4.5) and 64.2 (9.4) in 51 understudy plants, respectively. According to the results of sound measurement, sound level in 34 plants (66.6%) exceeded the permissible level and in 17 plants (33.33%) was below the limit. The results of screening forms showed that 47 plants (92.16%) had permissible level of noise while noise in 4 (7.84%) was not in permissible level. Chi square test revealed no significant relationship between the results of the two methods, based on the permissible and impermissible limits (p-Value=0.288). Furthermore, according to the regression analysis, R2 was obtained 0.357.

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Conclusion: No correlation was shown between the results of the two methods used. Thus, it is recommended to change the parameters used in the noise screening form for small plants, with less than 5 workers.

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Introduction: previous studies have shown approximately 90% of accidents in the workplace are due to unsafe behavior and human errors. Identifying predictors of unsafe behaviors would be unsafe in accidents prevention. The purpose of this study was to investigate personality characteristics, cognitive and organizational variables of line workers in an industrial company in bojnurd.

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Material and Method: The sample, in the main stage, consisted of 300 employees and in the validation stage 100 They were selected thought stratified random sampling. Firstly, participants were divided into two groups (safe and unsafe) using safety behavior scale. Next, each group was evaluated using the five-factor personality questionnaire, safety efficiency questionnaire, regulatory focus at work, safety climate, safety motivation and safety competency scales and also perceived work pressure questionnaire. In order to analyze the data, the discriminate analysis, the confirmatory factor analysis and the Pearson’s correlation coefficient were applied.

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Result: According to the result of the present study, unsafe behaviors of employees can be predicted by neuroticism, extroversion, agreeableness, consciousness, safety efficiency, regulatory focus and its dimensions, safety climate and its dimensions, safety motivation, safety competency and role overload variables.

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Conclusion: The results of this study showed the importance of safety competency, prevention focus, safety rules and procedures, safety efficiency and consciousness as predictors of unsafe work behaviors. Therefore, it is recommended to rely on these variables in the safety training courses and also in selecting people for high risk environments.

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Introduction: Heat stress in workplaces cause multiple problems such as thermal stresses, thermal discomfort and in more severe cases may lead to accidents and diseases related to excessive heat. The aim of this study was to evaluate heat stress adopting WBGT Index in some small enterprise in Qom city and also to examine the relationship between WBGT and physiological indices.

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Material and Method: This Cross-sectional study was conducted in 25 small workshops in Qom city including of 10 indoor and 15 outdoor workshops in August 2012. WBGT were measured according to the ISO7243 standard. The physiological responses including pulse rate, systolic and diastolic blood pressure were measured among 25 workers (one from each workshop).

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Result: The average WBGT index for indoor job were 27.55 Ċ among auto body repair, 27.45 Ċ in mechanics, 24.64 Ċ in painters, 26.73Ċ in welder and 25.89 Ċ in manufacturing doors and windows makers. For outdoor jobs as auto body repair, mechanics and painters it was 30.01 Ċ, and for welders and doors and windows makers 28.52 Ċ. Compared to the standard of ISO7243 WBGT all small workshops were higher than threshold limit. Auto body repair (30.22 Ċ) and painting (30.03 Ċ) workshops had highest WBGT. Average WBGT in auto body repair (as a job with most exposed to the open space and solar radiation) with welder and doors and windows, showed statistically significant differences T-test using WBGT with pulse rate, systolic and diastolic blood pressure did not have statistically significant (P>0.05). The findings indicated that workers are exposing to heat stress and doing more researches and representing preventive counter measures for the workers in this field are essential.

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Conclusion: Heat stress in almost all of the studied workplaces are higher than the recommended limits, and the outdoor workshops had the highest thermal stress, although heat stress did not show a significant correlation with the studied strains.

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Introduction: Electromagnetic field emitted by laptops are known as extremely low frequency (ELF) Waves. The aim of this study was to investigate the intensity of electric and magnetic field with extremely low frequency emitted by common laptops.

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Material and Method: Intensity of electric and magnetic field were measured on four sides of 40 common by used laptop at the distance of 30, 60 and 90 cm. Measurements ere done according to standard in four functional model including: non-performing turned on, sleep mode, performing office program and performing audio visual files.

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Result: Magnetic field values for all laptops were almost constant and about 28-32 mA/m. The results of measurements related to the electric field showed different values at distances of 30, 60 and 90 cm around the laptops on four sides. Moreover, mean electric field on the keyboard at the four operating modes were statistically different for DELL and hp laptops (P< 0/05).

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Conclusion: The results of this study showed that laptops produce extremely low frequency (ELF) electric and magnetic fields which their intensity depends on laptop type, laptop operation mode and the location of the measurement.

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Introduction: The present study aimed to test a model of the relationship between management commitment to safety and consciousness with unsafe performance,considering the mediating role of safety self-efficacy.

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Material and Method: Research design was the correlation throughStructural Equation Modeling (SEM) and the sampleconsisted of 265 employees of an industrialcompany who were selected by stratifiedrandom sampling method. Participants of this study completedsafety climatescale, short form of NEO personality questionnaire,safety self-efficacy scale, and unsafe performance questionnaire.Reliability and validity of the questionnaires were reported as acceptable. Evaluation of the proposed model was done by SEM through AMOS-21and SPSS-19 software packages. In addition, Preacher and Hayes’ SPSS Macro program was used for testing the mediating role.

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Result: The results showed that the proposedmodel fit the data properly.Management commitment to safety and consciousness had direct effect on unsafe performance and safety self-efficacy.Moreover, the mediating effect of safety self-efficacy in the relationship between management commitment to safety and consciousness with unsafe performancewas confirmed.

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Conclusion: Overall, organizations canreduce unsafe performance and consequently occupational accidentsby increasing the management commitment to safety and employees’ consciousness and also training of employees and supervisors to reinforce their safety self-efficacy.

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Introduction: Volatile organic compounds such as xylene, which are the main constituents of the oil and petrochemical industries, have serious impacts on health and can cause adverse effects on the environment. It is clear that release of these compounds into the environment should be controlled. The two-phases partitioning stirred tank bio-reactor is one of the newest methods for treating these compounds which have few side-effects besides of having appropriate efficiency since itdestroyscontaminant completely and transform it tosafer compounds.

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Material and Method: In this study, a two phase partitioning stirred tank bio-reactor, in lab scale, was used for treating the gas stream containing xylene vapors. The aqueous phase containing the bacteria Pseudomonas putida and nutrients inserted into the bioreactor with 3:1 ratio and system performance was evaluated for 432 hours in the concentration range of 1000 mg/m3 to 3500 mg/m3

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Result: Empirical findings of this study showed that the maximum, minimum and average of removal of xylene vapors by stirred two phase bioreactor containing a pure strain of Pseudomonas putida were 94.00, 54.00 and 84.94 percent, respectively.Furthermore, maximum, minimum and average of elimination capacity of xylene were obtained 93.00,24.00 and 62.02 g/m3/h, respectively

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Conclusion: Overall, the results of the present research revealed that the application of two phase stirred tank bioreactors (TPPBs) containing pure strains of Pseudomonas putida was successful for treatment of air streams with xylene.

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Introduction: Installation of wind turbines in residential areas due to their unique sound characteristics may cause noise annoyance. Noise annoyance can increase the risk of health problems and sleep disturbance. Thus, this study was conducted to assess the effect of wind turbine noise annoyance on sleep disturbance among the Manjil wind farm workers.

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Material and Method: All the Manjil wind farm workers have been divided into three groups according to their noise exposure levels, including maintenance, security, and administrative workers. The equivalent A weighted noise levels were measured for each of the study working groups, using ISO 9612 standard method. Information related to the noise annoyance and sleep disturbance were determined by ISO15666 standard and the Epworth Sleepiness Scale, respectively. Data were analyzed using R software.

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Result: Findings of ANOVA and Kruskal-Wallis statistical tests showed that noise annoyance and sleep disturbance were statistically different among workers with various occupational, age, and work experience groups. Also, noise annoyance and sleep disturbance had a significant association in a way that regardless of the effects of other variables, it can be stated that for every one unit increase in noise annoyance, 0.26 units will be added to the amount of sleep disturbance.

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Conclusion: In this study, workers with more wind turbine noise annoyance had more sleep disturbance. Therefore, in addition to the direct effects of noise on sleep disturbance, it can indirectly exacerbate sleep disturbances.

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Introduction: Requiring industries for implementing industrial waste management programs and planning for proper waste disposal is essential in order to achieve sustainable development. Therefore, industrial waste management program was done in Kavir Steel Complex, in Aran va Bidgol region to identify and classify industrial waste and also to present solutions for improving waste management. In this complex, production process is hot rolling steel and the product is rebar.

Material and Method: The preset study was conducted in Kavir Steel Complex. Following survey of production process and sources of waste, the type and volume of produced waste were identified and measured during 3 months. Then, the classification of wastes was done according to the Bazel Convention and Resource Conservation and Recovery Act (RCRA), and finally new industrial & health solid waste management program was presented.

Result: Considering the volume, industrial waste of production process in Kavir Steel Complex was between 130 to 180 grams per each ton of rebar. Main industrial waste included oxide of steel billet, industrial sludge, used oil and lubricant which were classified according to the RCRA: 8 materials with T code, 1 with C code, 5 with I code and 3 materials with C code.

Conclusion: The results revealed that the most amount of industrial waste in Kavir Steel Complex is the waste of steel billet and industrial sludge, and more than 90% of Kavir steel industrial waste were reused and recycled inside or outside of this complex. It is recommended that used oil to be transport and maintain in the safe containers.

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Introduction: Noise pollution in urban areas has been recognized as a major problem. Since hearing damages are the main concern of noise exposure, other physical and psychological effects should not be ignored. Noise-induced annoyance and consequently its side-effects, such as fatigue and loss of concentration, would increase the probability of human errors occurrence and occasionally irreversible occupational accidents. This matter show the importance of noise exposure level from the standpoint of both community health and workplace safety.

Material and Method: This cross-sectional study was conducted to investigate the annoyance caused by air transportation noise in tehran, 2014. In this sense, a sample of 200 individuals were selected from residential and nonindustrial noise-exposed population in four southwest regions in Tehran. Following, the study questionnaires including annoyance (Recommended based on ISO 15666-2003), visibility of airplane, noise perception, and demographic variables were distributed and completed by the participants. Data obtained from Integrated Noise Model (INM) and geographic coordinates of measurement stations, recorded by Glopal Positioning System (GPS), were entered into the GIS software in order to estimate air traffic noise.

Result: The present study showed that the equivalent sound level of all regions during night, the day average sound level only in the Simetry Jey area, and the average night noise level in all regions except Dorahi Ghopan were more than the acceptable level; and the most precentage of people with high annoyance was belonged to night annoyance rate. On the other hand, the correlation between day level (DL) and day annoyance rate (P=0.01, R=0.142), night level and night annoyance rate (P=0.004, R=0.334), and Day-Night Average Sound Level (DNL) and the day-night annoyance rate (P<0.0001, R=0.235) were obtained statistically significant.

Conclusion: Adopting management srategies for reduction of number of night flights or engineering measures such as improving construction to decrease the rate of receiving noise by exposed people can have a positive considerable effect on declining noise pollution and individuals’ annoyance rate.

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Introduction: Resilience engineering (RE), as a new approach in the system safety domain, is intended to preserve the performance of socio-technical systems in various conditions; and accentuates the positive activities instead of the failure modes. The aim of this study was to develop a new framework for safety assessment on the basis of RE, using the Fuzzy Analytical Hierarchy Process (AHP) method.  

Material and Method: Current study is an analytical cross-sectional survey performed in a petrochemical industry. Initially, six RE indicators were selected, including top management commitment, just culture, learning culture, awareness, flexibility and emergency preparedness and accordingly an assessment framework was established. Then, the selected RE indicators were evaluated and validated by experts in a specialized panel. Following, an indicator was proposed named “resilience early warning indicator”. Finally, the RE indicator score of the total process was determined using the fuzzy evaluating vector.   

Result: Findings revealed that top management commitment and learning indicators have the most and the least effects on the RE level of the process, respectively. Besides, the flexibility (C3) indicator was located in orange early warning zone (OEWZ) while other indicators were positioned in the no early warning zone (NEWZ). Furthermore, the overall resilience level of the process was evaluated as level III (NEWZ).

Conclusion: Management commitment and emergency preparedness are two main indicators of RE and can carry out the most important effect for remaining the RE in the NEWZ level.

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Diazinon is commonly used for pest control in the agricultural fields because of its relatively low cost and high efficiency. Due to the increasing application of pesticides, reliable and accurate analytical methods are necessary for their monitoring. This work was aimed to design the high selective electrochemical sensor for determining of diazinon in biological and environmental samples. The composition of sensor was modified with multi-walls carbon nanotubes and a molecularly imprinted polymer (MIP). A diazinon MIP was synthesized and applied in the carbon paste electrode (CP). The prepared sensor was used to determine the concentration of analyte. Parameters affecting the sensor response, such as sample pH, electrolyte concentration and its pH, and the instrumental parameters of square wave voltammetry, were optimized in different levels to select the optimum conditions for analysis of diazinon. The MIP-CP electrode showed very high specificity for determining the analyte. The obtained linear range was 1×10-6 to 5×10-10 mol L-1. The detection limit was 2.7×10-10 molL-1. This sensor was successfully used to determine the diazinon in environmental and biological real samples without special sample pretreatment before analysis.

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Introduction: Teaching has been reported stressful. Although, the majority of teachers aren’t anxious or unmotivated and they even consider their job valuable and satisfying. Job demands-resources (JD-R) is a comprehensive model in occupational stress domain that simultaneously examines the stressful and motivational aspects of occupations and their related outcomes. Accordingly, the objective of this paper is to investigate job characteristics of teaching (job demands and job resources) and their subsequent outcomes by utilizing proposed model.

Material and Method: This study was a cross-sectional design among 247 high school teachers in Tehran city who were selected by two-stage cluster sampling in spring and summer of 1391. Three aspects of job demands (pupil misbehavior, work-family conflict, and cognitive demand), 2 aspects of job resources (supervisory support and job condition), emotional exhaustion, vigor, teacher’s illness symptoms, and organizational commitment were assessed using job demands-resources model. The data were analyzed by means of SPSS 21 program and path analysis by using AMOS 23 program.

Result: According to the results, model fit indices were in acceptable range and all the coefficient paths were significant (p<0.001). Considering model, Job demands were a better predictor for emotional exhaustion (β=0.3) than job resources (β=0.2). However, they had an equal but opposite impact on vigor (β=±0.27). Moreover, we observed partial mediation relationships between job demands and illness symptoms and job resources and organizational commitment via emotional exhaustion and vigor respectively.

Conclusion: Based on the findings, fostering initiatives with priorities of firstly regulating job demands and secondly improving job resources can be effective strategies to reduce job related burnout and promoting job engagement, health and organizational commitment of teachers

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Introduction: The use of hearing protective devices (HPDs) is the last way for noise control. It is important to know the information about the duration time using these devices to ensure protetion effectiveness. The aim of this study was to investigate the effect of increasing duration time of the using of the devices on hearing loss in tile industry workers with application of the BASNEF education model.  

Material and Method: Task Base Method (TBM) and ISO9612(2009) standard methods through a noise dosimeter device were used to exmine workers’ noise exposure level when they didn’t used of HPDs. Actual performance of HPDs was determined by using the NIOSH standard before and after training intervention and measuring time of use and protection device type. Data were analyzed using SPSSVv19 and conducting t-test and ANCOVA statistical tests.   

Result: Before training intervention, the actual noise level for case workers was 89.76 dBA. On the contrary, this value was 84.04 dBA for after intervention, with a significant difference with control group (P<0.0001) using ANCOVA analysis. In control group, the actual level of noise has not changed because this group has not received any training.

Conclusion: The results revealed that, based on BASNEF education model, duration time of using hearing protection devices is effective on increasing their function and performance.

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Introduction: Job stress is one of the occupational hazards in the modern era. The National Institute for Occupational Safety and Health introduced the nursing job as a top 40 stressful jobs. In this job, multiple training techniques are considered to reduce stress and stress factors. This study was conducted to response the question “Is the use of health education programs can be effective in reducing job stress?”

Material and Method: Electronic search was done using key words in Persian and English database (Medical Sciences, Iran Medex), Scientific Information Database (SID), Bio Med Central, Pub Med, Science Direct) and were found 3,412 paper totally. Articles examined based on defined criteria and 9 qualified articles were discussed systematically.

Result: Among the reviewed studies, educational interventions in 7 studies were without, and 2 studies were with the use of health education models. The results of studies indicated significant effect of educational interventions on reducing job stress and using health education models in interventions had a greater effect on reducing job stress.

Conclusion: The results highlights the importance of educational interventions based on health education models to reduce occupational stress among nurses.

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Introduction: Considering the necessity of evaluating novel thermal indices for different individual and environmental conditions, the aim of this study was validation of a new enthalpy index for evaluation of heat stress in hot and dry climate.

Material and Method: In this descriptive analytical 97 city services outdoor workers were randomly selected and evaluated in spring and summer seasons in Qom city, Iran. Correlation between new enthalpy index and standard WBGT index, as well as physiological response of deep body temperature was studied and analyzed.

Result: Findings showed that regardless of the time of measurements, correlation between enthalpy and WBGT index was better than its correlation with tympanic temperature (R2= 0.756 versus R2= 0.391). Considering the time of measurement, it was found that with increasing temperature and decreasing humidity, the correlation between indices was reduced, although the correlation ratio was maintained similar.

Conclusion: Due to the simplicity of the enthalpy index measurement ,its independency to measure the globe temperature and the possibility of estimation of this index using daily climate parameters in meteorological stations, and on the other hand, appropriate validity of enthalpy against WBGT and core temperature, it can be a good alternative for WBGT index and as a screening index for thermal environments in hot and dry condition.

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Introduction: Chronic occupational noise exposure may constitute a risk factor for cardiovascular disease for workers. The aim of this study was to investigate the relationship between occupational noise exposure and noise annoyance with blood pressure, serum cholesterol and triglyceride levels in workers of a textile industry.

Material and Method: This cross-sectional study was carried out among 220 employees of Savadkouh textile industry complex in Mazandaran province, Iran in 2017. To achieve the study objectives, the 8 -hour equivalent sound exposure level was measured and the cumulative noise exposure was calculated. Based on noise exposure level, workers were divided into control and case groups. Then, blood pressure was measured and blood samples were collected from each individual for determination of the serum cholesterol and triglyceride levels and they were transfered to the laboratory for further analysis. The noise annoyance scale and socio-demographic questionnaire were used to collect noise annoyance and other background and demographic information, respectively. Finally, Paired t-test, one-way ANOVA and multivariate regression were used to study the relationship between variables using SPSS Version 20.

Result: In total, 159 workers participated in this study considering the inclusion and exclusion criteria. Eighty-three participants were exposed to more than or equal to 85 dBA, and 76 person were exposed to less than 85 dBA noise level, respectively. The results showed that mean blood pressure and cholesterol were significantly different between the control and case groups (P-value< 0.05). Based on multivariate regression results, noise exposure, cumulative noise exposure (CNE) and noise annoyance had a significant effect on blood pressure (P-value< 0.001).  Cholesterol was also significantly affected by noise exposure and noise annoyance (P-value< 0.005).

Conclusion: Based on the results of current study, noise can be considered as a risk factor for cardiovascular disease ampong workers. Actually, high intensity noise affect serum cholesterol and blood pressure directly, and may do indirectly by causing noise annoyance which acts as a mediator. Therefore, it seems necessary to conduct a controlled cohort study to investigating the interactions among whole variables of interest.

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Introduction: Nursing Known as a stressful and overwhelming profession. Due to the stressful nature of the nursing job, nurses experience burnout more than any other occupation, which may affect the quality of health care. Emotional intelligence is one of the important predictors of psychological well-being and it plays an important role as a distinguishing factor for organizational performance and achievement of job success. The purpose of this study was to determine the relationship between emotional intelligence and nurses' personal and occupational characteristics.
 
Material and method:  In this cross-sectional analytical study, 135 nursing staff working in Gonabad hospitals was selected through a census sampling method. Written informed consent of nurses and working in hospitals of Gonabad city were the inclusion criteria and Failure to complete the questionnaires or the questionnaire being confounded or withdrawal from the study was considered as the exclusion criteria. They were evaluated by Shirring Emotional Intelligence Questionnaire and Demographic Information Form. The research data were analyzed using SPSS software version 16, Chi-square test, one-way ANOVA and Pearson correlation coefficient. The significance level was less than 0.05.
Results: In this study72.6% of participants were women. The majority of nurses were married (81.5%) and 87.4% of nursing staff had high emotional intelligence. In this study, there was no significant relationship between individual characteristics and emotional intelligence, but there was a significant association between job characteristics, job shift (P = 0.03) and employment status (P = 0.03) with total emotional intelligence. The results showed that there was a significant relationship between social consciousness with education level (p = 0.019) and employment status (p = 0.001) and there was a significant relationship between social skills with work shift (p = 0.003) and nurses' marital status (p = 0.007)
Conclusion: According to the findings, considering the appropriate job shifts for nurses and formalizing them to create a strong organizational commitment to take benefit of nurses with higher emotional intelligence and this leads to improved performance of nurses.

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Introduction: Designing behavioral modification interventions for the use of personal protective equipment (PPE) warrants the audiences identification and analysis. This study aimed to determine the predictive factors for using (PPE) based on Social Cognitive Theory (SCT) constructs among workers of Iran Aluminum Factory, 2018.
Material and Methods: In this descriptive analytical study with cross-sectional method, a researcher-made questionnaire including demographic information, knowledge questionnaire and designed items based on the SCT construct, was fulfilled by 188 workers employed in production line of Iran Aluminum Factory in Arak. The collected data was analyzed using descriptive statistics, Chi-square and logistic regression analysis on SPSS 24. The significance level was set at P< 0.05.
Results: Among the participants, 46.8% (n=88) and 52.2% (n=100) of workers had moderate and high level of knowledge, respectively. Demographic variables such as marital status, educational level, income, age, work experience and employment status (p <0.05), as well as all SCT constructs (p <0.05) had a significant relationship with knowledge. Logistic regression analysis revealed that the level of education and employment status with probability of 80.6% and self-control, environment and self-efficacy of perceived barriers constructs, with a 64% probability could explained workers in high-knowledge group.
Conclusion: The present study revealed that the variables such as level of education, employment status, self-control, environment and self-efficacy of perceived barriers could be effective in designing educational interventions to improve workers’ knowledge on using personal protective equipment.