Journal of Health and Safety at Work

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Introduction: Heat stress is caused by many factors such as individual factors, environmental factors, and management factors. Individual risk factors can decrease the heat tolerance, and play an important role in heat stress disorders incidence. The aim of this study was to review individual parameters influencing the thermal stress and review the preceding studies.

Material and Method: In this review study sites such as Web of Science, Scopus, Pubmed, Iran Medex, Magiran, Google Scholar and SID databases were used for search. The keywords included heat stress, personal factors and heat exposure. The period of 1995 to 2015 was investigated, and finally 75 original articles were identified.

Result: At the individual level, exposure with a single risk factor may reduce the workers’ heat tolerance; while exposure with a combination of several risk factors probably synergistically increases the risk of heat-related disorders. Individual risk factors include age, gender, obesity, fatigue, race, and previous heat disorders and dehydration. In addition, some diseases (such as cardiovascular disease, diabetes and infectious diseases) or use of certain drugs or alcohol can reduce the heat tolerance.

Conclusion: It is necessary to pay attention to the mentioned items when selecting workers in the hot environments. Also, due to the lack of awareness and knowledge of workers, it is necessary to provide appropriate training programs to reduce the effects of heat stress.

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Introduction: Correspondence analysis method and preparation of accidents and occupational hazards pattern is able to predict and anticipate accidents and is automatically prioritize the risks and injuries. The aim of this study was to present accidents and occupational hazards pattern based on risk-injury groups, which use it to manage of occupational accidents.

Material and Method: The report of occupational accidents, registered in the social security organization was collected in a period of ten years from 2005 to 2015 (222,300 accidents). Types of risk and injuries to any of the accidents specified based on International Labor Organization criteria and risk of injury were classified in a matrix (18 × 18). Risk-injury groups were separately identified using correspondence analysis and collapse process, as patterns of accidents and occupational hazards. In the mentioned patterns, the relationship between risks and damage can be identified, as it facilitates decision-making in risk assessment in companies covered by the social security organization.

Result: According to the findings, three groups of occupational accidents were obtained and variables of these three groups extracted from the obtained patterns. The first group included six risks and seven injuries that the risks variables were: contact with hot materials, accidents caused by caustic  and corrosive substances, contact with chemicals, accidents caused by toxic substances, contact with electrical equipment, explosion and fire, and injuries were: burns, other injuries, multiple injuries, gas poisoning, suffocation, poisoning, environmental hazards. The second group included seven risks and six injuries that the risks variables were: accidents caused by displacement, projections of fragments or particles, accidents caused by machine tools, slipping, falling people, falling objects, other accidents and injuries were: twists and sprains, dipping the objects in the body, objects in the eyes, cuts and amputations, superficial wounds, deep wounds. Finally, the third group included five risks and five injuries that risks variables were: Falling under the rubble, accident with vehicle, accidents caused by displacement, colliding of persons against objects, projections of fragments or particles, accidents caused by manual tools, trapped between objects, accidents caused by machine tools and injuries were: fractures, dislocation, back pain, hitting, contusions and crushing. It should be noted that the study of these patterns can be used to identify and prioritize of occupational accidents.

Conclusion: The proposed groups make new opportunities for development of the applications to analyze, interpret and automate management of occupational accidents in order to minimize uncertainty and increase its objectivity. Its advantage over other similar analyses can be considering both the risks and injury and to obtain groups of two variables. Due to the frequency and distribution of mass of risk and injury variables in the groups, the risk and injury variables of group 3 are the most important, and the risk and injury variables of group 2 are less important and the risk and injury variables of group 1 have the least importance.

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Introduction: Choosing maintenance strategy is one of the most complex and essential processes that can affect the safety and cost of equipment. The main aim of this study was to determine a risk-based maintenance policy for improvement of the safety and maintenance indices.

Material and Method: According to literature reviews and constraints associated with the studied industry, a number of safety and maintenance indices were selected and their values were measured. Next, in order to promote the selected indices, the best policy was implemented on nine critical machines of the company based on criteria such as cost, risk and availability in the framework of the fuzzy network analysis process. Finally, after six months period, the indices were re-measured. The Wilcoxon test was used to assess the changes in the indices.

Result: In the implementation of the model, condition based maintenance was more effective than other strategies. Following the intervention, the improvement of safety and maintenance indices was statistically significant. The statistical analyses demonstrated that indices like reliability, availability, mean time between failures, and the number of dangerous failures all were improved significantly (P<0.05).

Conclusion: The results showed that the simultaneous use of three criteria, i.e. cost, risk and availability in maintenance planning could reduce equipment-related accidents. Finally, the recommended model can improve the efficiency and competitiveness of organizations by increasing availability and reducing equipment costs

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Introduction: Kitchen workers are in danger of slip accident because of slippery surfaces created by contaminants like grease, water and food material. The aim of this study was to investigate the prevalence and slip risk assessment in cooking sites of Shiraz.

Material and Method: This cross-sectional study was conducted on 322 cases from commercial kitchens in traditional and fast food restaurants, located in Shiraz, Iran, who was willing to cooperate in the project. (The total number of restaurants was 1303 cases. And simple random sampling method was used). The risk of slips was assessed using Slip Assessment Tool (SAT), developed by Health and Safety Executive (HSE). Prevalence of slip accidents was investigated using a questionnaire among kitchens staffs. Roughness coefficient was measured using Roughness Meter TQC-SP1560. Data analysis was performed using SPSS-22 software.  

Result: The level of slip risk was at moderate level in 47% of studied kitchens and others had low level of slip risk. Slip risk level in kitchens of traditional restaurants was significantly higher than fast foods. The average value of the measured surface roughness was obtained 4191/39 µm. The highest and lowest, respectively 4458/2 and 3977/3 µm were reported. The prevalence of slip accidents was reported to be 50.3%. Most of slip accidents was occurred in the kitchens, and when the floor was wet with water or contaminated with food products.

Conclusion: The results of this study showed that due to differences in the type, method and time of food services and also workload of personnel, slip risk in kitchens of traditional restaurants was higher than fast foods. Approximately, in 50% of studied kitchens, the level of slip risk was assessed as moderate. Some basic interventions in spillage control and cleaning procedures, floor surface characteristics and using slip-resistant shoes are required to reduce the risk of slip in kitchens.

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Introduction: Adverse effects of volatile organic compounds (VOCs) including general and specific effects like carcinogenic of benzene are well known. The aim of this study was to evaluate occupational exposure to BTEX compounds in the painting unit of an automotive industry and subsequently health risk assessment of exposure to these compounds.

Material and Method: This cross-sectional study was conducted in the paint unit of an automotive industry including painting cabin, pre-painting salon and painting salon sections. After analyzing samples, gathered from different sections, by GC-MS, BTEX compound were identified as the main contaminants. In the next step, NIOSH1501 and EPA methods were used to measure and analysis of BTEX and risk assessment, respectively.

Result: Findings showed that benzene concentration in painting cabin was higher than occupational exposure limits provided by the Environmental and Occupational Health Center of Iran. Life time cancer risk for benzene per 1000 has been reported10, 3.63 and 1.27in the painting cabin, pre-painting and salon sections, respectively. It was also for ethyl benzene 2.5m 1.8 and 38.0 in the mentioned sections, respectively. The non-cancer risk for benzene and xylene in the painting cabin and pre-painting sections were higher than recommended allowable level.

Conclusion: Regarding the high level of cancer risk values obtained for benzene and ethylbenzene in the studied units and also high values of non-cancer risk for benzene and xylene, it is recommended to conduct biological exposure assessmnet of the workers and improve existence control systems using modern engineering control systems.

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Introduction: Extensive human and economic losses due to the fire accidents shows the necessity of scientifically dealing with major industrial fires, , investing in the development of fire protection technologies and determination of the most effective techniques to limit damages. This study is conducted to evaluate the effect of active and passive protection methods on reducing the level of fire risk, in the control room of a thermal power plant.

Material and Method: In the first phase of this study, fire risk level for buildings, goods, occupants and activities was calculated using Fire Risk Assessment Method for Engineering. In the second phase, from 36 sub-factors affecting risk level, three sub-factors of passive protection measures and two sub-factors of active protection measures were analyzed and modified, in reducing the fire risk level of occupants.

Result: The results of the present study showed that occupants’ fire risk level (20.64) is above the acceptable level. Correction of three sub-factors, including constant fire load, floor number, and changing the dimensions and area of the control room up to 40% and installing an automatic fire extinguishing system and training the occupants to use fire extinguishing equipment and emergency evacuation up to 33%, is effective in reducing the fire risk level.

Conclusion: Passive and active protection methods, despite their impacts on reducing the level of risk, cannot provide an acceptable level of fire safety independently. Therefore, combined use of these methods is essential to protect buildings and people, and prevent any interruption in the system’s activities.

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Introduction: Risk assessment is a main tool in safety management process as it can help managers to choose corrective actions by providing appropriate information. The purpose of this paper was to select the optimal corrective actions among the proposed ones by the experts based on mathematical modeling, taking into account the standards and also the limitations including the cost.

Material and Method: In this paper, a model was presented to find the optimal corrective actions regarding the organization goals (maximum in risk reduction value) and the limitations such as cost and level of acceptable risk. Due to extensive number of solutions, Genetic Algorithm (GA) is used for solving the problem.

Result: To show the capability of this method in an industrial environment, a power generation industry with 40 hazards was considered as the case study. Then, the risk of hazards was estimated and corrective actions were determined for each of them. Using the proposed model, corrective actions were selected optimally, with the least possible cost; all risks were reduced below the level of organizational acceptable risk.

Conclusion: It was shown that the optimal corrective actions using mathematical modeling are selected with high precision in acceptable time. This method is suggested as an alternative for conventional qualitative methods based on expert’s opinions.

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Introduction: Workers in steel manufacturing companies are extensively exposed to the volatile organic compounds (VOCs). Considering the health effects of these compounds, the purpose of this study was to determine occupational exposure to the BTEX compounds and also evaluation of carcinogenic risk due to benzene and non- carcinogenic risk for BTEX compounds in a steel industry.

Material and Method: This cross-sectional study was conducted in the coke production unit of the steel making industry. After collecting personal samples from breathing zone of the workers and analyzing of the samples the levels of exposure to the BTEX were quantitatively determined using Gas chromatography equipped with Flame Ionization Detector (GC-FID), according to the NIOSH 1501 standard method. Then, cancer risk due to benzene and non-cancer risks from BTEX compounds were calculated using Monte-Carlo technique.

Result: The analysis of personal samples indicated that benzene concentration in energy and biochemistry and benzol refinement sections of the plant were higher than occupational exposure limits (OELs). Among the studied sections, benzol refinement as the most polluted section had the highest concentration of BTEX compounds. Non-cancer risk due to BTEX compounds in all studied sections was lower than one. Benzene cancer risk in energy and biochemistry, benzol refinement and experimental furnace sections was higher than maximum recommended value by EPA.

Conclusion: Due to the high concentration of benzene in energy and biochemistry and benzene refinement sections as well as the resultant carcinogenic risk, improvement of existing control systems and the use of modern engineering systems are necessary to control occupational exposure.

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Introduction: Working in hot and harsh weather conditions can cause heat related diseases and in some cases, even can lead to death. Risk assessment of heat stress in these environments is of particular importance. As there are many factors that could affect the heat stress, therefore, an index should be applied that could properly reflect the effect of all of these factors.
Material and Method: Initially a five-member expert team was established. Then, the weight of each variable was determined by the fuzzy analytical hierarchy process (FAHP) method. In next step, five work stations of the casting process evaluated applying fuzzy TOPSIS (FTOPSIS) method and the risk of heat stress prioritized in these stations. Lastly, the Pearson’s correlation coefficient was used to determine correlation between the results of proposed method with WBGT index.
Result:  The weights of three main variables including task characteristics, working environment, and worker characteristics was determined as 0.279, 0.526, and 0.195. The risk priority of the five work stations including, stocking, melting furnace, pouring and casting, polishing, and warehousing was established as S1= 4, S2= 2, S3= 1, S4= 3, and S5= 5. The Pearson’s correlation coefficient between the similarity index (CCi) and WBGT was 0.97.
Conclusion: From three main variables that can affect the heat stress, “Working Environment” has main impact in the risk assessment process; therefore, the most efforts must be focused on controlling this variable. The proposed method in this study has the capability of concurrent quantitative and qualitative assessment of factors that could affect the heat stress and can minimize the uncertainties in the risk assessment process relying upon the fuzzy sets.

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Introduction: Fire and explosion are the most common consequences of natural gas pipeline accidents. The results of previous studies showed a higher rate of accidents in natural gas transmission lines. Given that a large number of people living in the vicinity of natural gas pipelines with a higher severity of related accidents. The aim of current study was to estimate risks using the method of quantitative calculation of risk and simulation of natural gas pipeline leakage using areal locations of hazardous atmospheres (ALOHA) in natural gas power generation.  
Material and Methods: The method of quantitative calculation of risk was used to identify and prioritize risks. The simulation of the consequences of natural gas pipeline leakage was done by ALOHA software. Calculations of individual and social risks were performed based on statistical data obtained from the literature.
Results: The most serious effect of natural gas pipeline leakage was heat radiation effect of jet flame. Considering three leakage apertures in the natural gas pipeline 80, 130, and 300 mm, individual risks for each leakage aperture were 0.073, 0.114, and 0.569 and the number of deaths was 115, 400, and 3386, respectively. Increases in the leak aperture can lead to an increase in the number of deaths and decrease in the cumulative rate of accidents.
Conclusion: The most serious consequence of natural gas pipeline leakage was heat radiation effect of jet flame. The individual risk and social risk are beyond the acceptable risks range.

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Introduction: One of the harmful pollutants in the indoor environments is particulate matters. Particles smaller than 2.5 micrometer in diameter that are suspend in the industrial environments air are the most deleterious dusts which can cause lung disease and cancer. In present study PM2.5 concentration in the fast-food shops air and its cancer risk for shop workers were assessed.  
Material and Methods: In this descriptive-analytical study, all of Sari city 132 fast foods were included. Air sampling was conducted by calibrated real-time GRIMM-monitor device. Data were analyzed by using of SPSS16 and Prism6 software with T-test, Pearson correlation and descriptive statistics. Finally PM2.5 cancer risk in workers was calculated by EPA method equation.
Results: The PM2.5 concentration in shops indoor air (308.5µg/m3) significantly was higher than its concentration in outdoor air (121.98µg/m3) (p<0.05). Highest correlation was observed between indoor PM2.5 concentration with smoking (0.366) and local ventilation (-0.384) (p<0.01). The concentration PM2.5 in the indoor and the outdoor of shops was 273.55 and 86.98µg/m3 higher than acceptable level respectively. Cancer risk was 5.6 per 100 thousands and 1.97 per 10 thousands in the rest and cooking time respectively.
Conclusion: The most affective source in the elevation of PM2.5 level in shops indoor air is the cook-emitted particles. PM2.5 concentration in shops indoor and outdoor air was much higher than EPA admissible level and cancer risk for workers was unacceptable that it has required to basic solutions for air pollution control at source.

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Introduction: Evaluating environmental risks in the oil and gas industry is essential to prevent irreparable damage to the environment. Using classical methods for prioritizing environmental risks does not achieve high-reliable results. Therefore, the aim of this study is to minimize the limitations of classical methods in a typical oil and gas production zone, by using fuzzy logic and Multi Attribute Decision Making (MADM) approach.  
Material and Methods: After forming an identification and assessment team including experienced experts from different organizational units in a region of exploitation of oil and gas, values of each risk factor (likelihood of occurrence, severity and detectability) related to identified environmental risks are determined according to their qualitative opinions represented by linguistic variables. Relative weights of the risk factors are calculated by applying the group Analytic Hierarchy Process (AHP) in a fuzzy environment on expert opinions. Then, fuzzy aggregation in the linear form by considering the weight of the risk factors and a method that is developed based on the center of gravity are employed in evaluation and ranking of the risks.
Results: In this study, the severity factor has the most important contribution in risk assessment compared to the other risk factors, since it has the highest relative weight. Raw sewage aspect resulted from absence of appropriate treatment system has the highest priority and spilling over of acid that is caused by chiller cleaning stands at the second position in the identified environmental risks.
Conclusion: The results demonstrate that although the proposed methodology requires greater time than classical methods, it is able to determine the risk ranking more practically because of minimizing the limitations of classical methods: high sensitivity to judgmental errors, considering some risks in the same index group and ignoring uncertainty in experts’ opinions. Proposed method is a proper alternative for classical environmental risk assessment technique, and capable of prioritization and evaluation risks in terms of safety and health.

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Introduction: Nearly a third of people work in jobs that use voice to be part of their work. Teachers as the largest group of professional vocal users, are at risk of vocal disorders. The aim of this study was to investigate the effect of different risk factors on vocal disorders in teachers.  
Material and Methods: This is a cross-sectional and descriptive-analytic study that was conducted on 73 primary and secondary male and female school teachers in Saveh in 2017 by random sampling. The researcher-made questionnaire on risk factors affecting verbal disorders with the aim of identifying risk factors and a Voice Handicap Index (VHI) questionnaire (30 items) aimed at evaluating verbal disorders and symptom questionnaire were used in this study. All of them have been shown to be valid and reliable in previous studies. Data were analyzed using t-test and chi square statistical tests by SPSS ver.24.
Results: The reliability of the researcher-made questionnaire on the risk factors affecting vocal disorders was confirmed by Cronbach’s alpha (0.736) and its validity was confirmed by the experts regarding the adequacy of the number of questions, the lack of ambiguity and the assessment of content fitness. According to our gathered data, vocal disorders were observed in 55% of the teachers. Also the results showed the rate of vocal disorders in female teachers is far higher than male teachers. Functional disturbance of vocal cords and allergy as general risk factors, teaching tools and poor air quality as environmental risk factors and inadequate vocal rest and job stress as occupational risk factors contributed to increasing vocal disorders in teachers. Among the symptom associated with verbal disorders in teachers, vocal fatigue and hoarseness were more common in comparison with other symptoms.
Conclusion: Due to the prevalence of vocal disorders in half of the teachers and the impact of general, environmental and occupational risk factors, it is necessary to identify and control the risk factors of vocal disorders in teachers. It can also be concluded that teachers can enjoy a healthy voice by considering the principles of ergonomics and occupational health.

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Background: Industrial incidents are one of the major problems of today's societies. Studies in this field show that the main and most important cause of error occurrence is human factor. Therefore, the aim of this study was to identify and evaluate the risk of human error in the activities related to the operation of electrical installations of the Tehran Province Electricity Distribution Company.
Methods: This study is a qualitative and cross-sectional research was conducted by direct observation of the activities and documents, interview. Tasks and subtasks were selected and analyzed using Hierarchical task Analysis, (HTA).The results were presented in the form of  HTA. Finally, according to the instructions of SHERPA, the relevant worksheet was completed.
Results: The analysis of SHERPA worksheets showed that a total of 3399 errors were detected for 759 tasks as 39.57% of them were action errors, 32.4% review type, 7.32% recovery type, 19.64% communication type and 1.80% were selective errors. According to the results of risk assessment, 12.47% of the errors were unacceptable risks level, 59.57% were undesirable, and 20.2% were acceptable risks but need to be revised and the rest, 7.33% acceptable with no need for revision or safe ones.
Conclusion: According to the results, the most common type of error was action errors and in order to reduce this type of errors, using necessary corrective measures such as proper selection of people for occupations, training, monitoring, using smart machines, using tag out systems and checking at the suitable time and updating the instructions would be useful and effective countermeasures.

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Introduction: Hazard Identification, risk assessment and management have an important role in reducing potential risks in industrial settings. This research was done with the aim of identifying the hazard and evaluating HSE risks and providing a HSE management program for the Urea Unit of Shiraz Petrochemical Complex.
Method: Firstly, hazard identification and qualitative risk assessment was done using FMEA technique and risky units were identified. Then, main events were identified and analysed as inputs of the Bow-Tie method. By identifying the strength, weakness, opportunity and threat factors, ranking and weighting them using the ANP method and Super Decisions software, a SWOT matrix was prepared and HSE management strategies were extracted.
Findings: The results showed that chemical leakage, falling from height and slipping were the most important incidents, and defect of control equipment, lack of attention to instructions, non-compliance with safety principles and human error were causes of these events. Also, ranking of weaknesses, strengths, opportunities and threats were 0.58, 0.2, 0.16 and 0.05, respectively.
Conclusion: Organizational opportunities with a weight of 0.124 were 4.8% higher than threats with a weight of 0.076. This shows that the company had a good situation in terms of achieving its goals.

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Introduction: Risk identification and investigation is an appropriate and practical approach for the occupational health professionals. This paper aims to determine exposure to the gases and metal fumes and to perform risk analysis in three common types of welding activities in a shipbuilding industry.
Material and method: This analytical cross-sectional study was conducted in a shipbuilding industry and three types of welding were considered including SMAW, MIG and MAG welding. Sampling of Mn and Cr fumes was carried out using NIOSH 7300 standard method, and NIOSH 6014 method NO2 sampling, and also direct reading devices for CO and O3 gases. Moreover, SQCRA risk assessment method was adopted to specify the level of exposure risk.
Results: The results of risk analysis showed that among gas pollutants, O3 and NO2 in all welding processes had a very high-risk level, while among the metal pollutants; Mn metal showed a high and very high risk level in MIG and SMAW welding.
Conclusion: According to the both sampling results and risk analysis, MIG process welders are more dangerous position than other types of welding.

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Introduction: 1,3-Butadiene is a carcinogenic compound that can be emitted to the atmosphere from several sources like petrochemical industry. One way to determine the level of carcinogenic and health effects of respiratory exposure to pollutants in the workplace is to use risk assessment methods. The aim of this study was to comparative assessment of carcinogenic risk of respiratory exposure to 1,3-Butadiene in a petrochemical industry by the US Environmental Protection Agency and Singapore Health Department methods.
Material and method:  This cross-sectional study was carried out in 2018 in a petrochemical industry that producing copolymer ABS (acrylonitrile, butadiene, styrene) in Iran. Occupational exposure to 1,3-Butadiene was measured according to the NIOSH 1024 method. Cancer risk assessment was done according to the United States Environmental Protection Agency (USEPA) and Singapore semi-quantitative methods.
Results: The average occupational exposure to 1,3-Butadiene during work shift among all participants was 560.82 ± 811.36 µg.m^-3 (0.253 ± 0.367 ppm) and in all cases was below the occupational exposure limit. The average lifetime cancer risk in USEPA method in the present study was 2.71 × 10^-3, Also in this method 82.2% of all exposed workers were in the definite carcinogenic risk level and 17.8% were in the probable carcinogenic risk level. The results of the Singapore health department method showed that 91.2% of all subjects were in the probable carcinogenic risk level and 8.8% were in the definite risk level.
Conclusion: The findings of the present study showed that the results of the Singapore semi quantitative risk assessment method are not in good agreement with the results of the quantitative risk assessment method proposed by the US Environmental Protection Agency. Therefore, given the high accuracy and thoroughness of the US Environmental Protection Agency's risk assessment methodology as a worldwide reference method for assessing the carcinogenic and health risk of exposure to chemicals, it is recommended to use this method instead of the Singapore method in future studies.

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Introduction: Commercial complexes are one of the most prestigious public and city-centered areas in terms of urban safety and passive defense. The purpose of this study was to determine the fire safety risk score of commercial complexes and its related factors.
Material and method:  The commercial complexes of area 1 of District 12 of Tehran were studied. The characteristics of the complexes, including construction, height, activity, Occupancy Coefficient and etc in each complex were collected. fire risk assessment was performed using NFPA101 standard and CFSES software in three areas of control, Egress and general safety. In SPSS software version 21, linear regression and ANOVA tests were used to determine the relationship between variables.
Results: Of the 79 commercial complexes studied, only 8 in control area and 4 in general area achieved acceptable risk level. None of them achieved an acceptable score in the Egress. According to the results, there was no significant relationship between risk levels and height, type and activity Coefficient of them(p>0.05). However, between Occupancy Coefficient of complexes with fire safety risk levels of control(p<0.001) and general(p= 0.013) and between construction with all risk levels ((p_Egress= 0.004), (p_Control & p_General<0.001)) There was a significant relationship.
Conclusion: The results showed the current situation of the studied commercial complexes is prone to cause a disaster in the 12th district of Tehran; Using the results of this study in urban planning and cross-sectoral communication to improve the safety of commercial complexes in the region is suggested.

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Introduction: Styrene (C₆H₅CH=CH₂) is known as one of the volatile organic substances produced or used in petrochemical industries. Exposure to this chemical compound can thus lead to respiratory diseases. Therefore, this study aimed to evaluate occupational exposure to styrene vapor and to determine the risks of its health consequences in petrochemical industry workers through a quantitative method.
Material and Methods: In this descriptive cross-sectional study, a total number of 150 samples from 50 employees were studied using the National Institute for Occupational Safety and Health (NIOSH) 1501 method. The samples were then analyzed by the Varian CP-3800 chromatograph. Upon determining exposure to styrene vapor, the risk assessment of the health consequences of styrene in the workers in the given industry was evaluated via the relationships established by the United States Environmental Protection Agency (US/EPA).
Results: According to the results, the polybutadiene latex unit (PBL) was observed with the highest average exposure (0.44 mg.(kg-day)-1). Therefore, the top predictors of carcinogenic and non-carcinogenic risks were valued 0.44 and 0.71, respectively, for the PBL unit. Given the lowest average exposure (0.0012 mg.(kg-day)-1) in the drying unit, the prediction revealed the most moderate carcinogenic (0.1 ×10-5) and non-carcinogenic risks (2×10-3) for the same employees.
Conclusion: Overall, the health risk was higher than the permissible limit in the petrochemical industry studied, especially in the PBL unit. Therefore, it is recommended to make use of artificial ventilation, notably the local type, in addition to the natural ones.

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Introduction: The main purpose of this study was to identify and evaluate environmental problems and their ranking and to determine the conceptual model of environmental impact assessment (EIA) in industrial parks. Accordingly.
Material and Methods: In this study, environmental infrastructure issues were classified into five sections. The decision-making trial and evaluation laboratory (DEMATEL) technique was also employed to establish the relationships between the criteria. Moreover, the analytic network process (ANP) was utilized to determine their weight.
Results: Examining the internal relationships between the variables correspondingly revealed that cultural and economic criteria were the most influential. On the other hand, the biological criterion was very effective. The ANP results also showed that the “low share of environmental investment” as an indicator was an economic criterion with a normal weight of 0.80, which was of utmost importance among the other defined cases.
Conclusion: It was concluded that the definition of conceptual models in EIA processes can make it possible to examine and analyze the criteria and indicators affecting evaluation processes.