Journal of Health and Safety at Work

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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: Many studies have been carried out on the effects of heat stress on cognitive functions, but the results are contradictory. Therefore, this study was conducted to review the effect of heat stress on cognitive functions.
Material and method:  In this study, all English articles conducted on effect of heat stress on cognitive, perceptual, and psychomotor functions from 1970 to 2018 were reviewed. For this, articles with keywords such as heat strain, heat stress, cognitive function, memory, comprehension, psychomotor, reaction time, mental performance, mood, mental response, error, task performance, fatigue, alertness, hyperthermia, and heat exhaustion in the  Scopus, Web of Science, Science Direct, Pub Med, Springer, Wiley Online Library and ProQuest databases were searched. Out of 157 retrieved articles, 39 articles were finally reviewed according to the inclusion criteria.
Results: Out of 157 retrieved articles related to the topic, according to the inclusion criteria, 39 articles were finally considered for review. Among this articles, 9 (%23) articles were published before 2000 and 30 (%77) after 2000. Two articles were in athletes, four articles (%10.2) in workers, four articles (%10.2) in students, four articles (%10.2) in military soldiers and twenty-five articles (%64.2) were conducted in ordinary people.Based on the results, heat stress was identified as a detrimental factor for decreased cognitive functions such as reading comprehension, memory, focus, mathematical processing, tracking test, reaction time, perception  and decoding text and numeric messages, visual alertness, mental computing, text reading , hidden figures test and verbal fluency.
Conclusion: Based on the results of these studies, heat stress has been introduced as a detrimental factor for disrupting cognitive functions, but conclusion based on the results of studies is a systematic method is difficult because many confounding variables such as type of work, exposure time, skill and adaptation plays a big role.

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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 skin, can be exposed to harmful factors like ultraviolet radiation (UV). Exposure to this physical hazardous agent could be contributed to pigmentation, erythemas, early aging, skin cancer, and DNA damage. The aim of this study, therefore, was to fabricate the polyacrylonitrile (PAN) nanofibers with the UV protection property by the use of various concentrations of titanium dioxide (TiO2) nanoparticles.
Material and Methods: The PAN nanofibers (10%wt) containing 0, 1, 5, 10 and 15% wt of TiO2 nanoparticles were produced using electrospinning method. The morphological propertis of nanofibers were studied by scanning electron microscopy (SEM) and the functional groups were investigated by Fourier transform infrared spectrophotometer (FTIR). The UV protection property of nanofibers was studied by measuring UV transmittance as well as calculating UV protection factor (UPF).
Results: The results showed that the diameter and morphological characteristics of nanofibers are different at various concentrations of TiO2 and increasing the concentration of TiO2 has resulted to an increase in nanofibers diameter. The analysis of FTIR results showed that TiO2 nanoparticles have been successfully loaded on nanofibers for UV protection purposes. The findings clarified that nanofibers loaded with TiO2 could increase the UV protection property up to 15%.
Conclusion: Totally, our findings show the successful fabrication of UV-protective nano webs using TiO2 nanoparticles. the new combination used in nano matcould protect employees from UV radiation.

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Introduction: The respiratory system, one of the most important organs of the body, can be affected by adverse effects, disorders and consequences in the workplace. Spirometry is one of the most important screening and testing tools in the periodic medical examination of every employee. This study was aimed to evaluate the factors affecting the respiratory function of staff of Tehran University of Medical Sciences (TUMS).
Material and Methods: This descriptive-analytical and cross-sectional study carried out on 300 employees of TUMS according on during the enrollment phase of the Tehran University of Medical Sciences employee’s cohort (TEC) study was in order to survey the parameters affecting pulmonary function. Demographic data were collected through a demographic questionnaire. Spirometry was used to evaluate respiratory function parameters and bioelectric impedance was used to analyze body composition. Data analysis was performed by SPSS software version 25. Two-sample t-test, one-way ANOVA, and Pearson correlation coefficient were used for statistical analysis. Multiple linear regression was used to determine the effect of independent variables on the parameters of pulmonary function.
Results: It was found that 73.6% of the subjects had a normal lung pattern, 7% had an obstructive pattern, 14.7% had a threatening pattern and 4.7% had a mixed pattern. There was a significant negative correlation between FVC and FEV1 parameters and smoking (P-value <0.05). There was also a significant relationship between FFM, age and BMI with FEV1/FVC (P-value <0.05). Similarly, there was a meaningful relationship between type of job and FVC parameter (P-value <0.05). The findings showed that the highest and the lowest averages of all parameters of pulmonary function was in administrative and occupational services, public and technical services and facilities, security and guard, respectively.
Conclusion: In the present study, it was found that occupation type affects lung function due to exposure to contaminants in different groups. Other factors affecting lung function included age, body mass index, fat mass, fat free mass and smoking. Therefore, changing lifestyle such as proper diet, regular exercise and not smoking can be an effective step towards improving the parameters of lung function.

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Introduction: Each country needs to preserve its human capital through preventing accidents for its development. Therefore, this study is carried out to study the relationship between safety investments and safety performance indices considering the interactive effect of the project hazard level in construction industry.
Material and Methods: This study was conducted using multiple case studies in 5 major construction worksites, in Tehran, in 2019. Data was collected using questionnaire, checklists and interview as well as evaluating the safety documents. The data analysis in this study was carried out using SPSS 18.
Results: There was a strong inverse correlation between safety investments (total safety investment, basic safety investment, and voluntary safety investment) and accident frequency rate (AFR) (r=-0.936, P-value<0.05), and there was a direct strong correlation between safety investment and safety performance (P-value<0.05, r=0.939). Also, the effect of various safety investments on safety performance indices under various project conditions (project hazard levels) was not the same; when the project hazard level was high, the effect of safety investments on safety performance was higher.
Conclusion: Increasing safety investment improves safety performance through decreasing the accidents. Also, investment in both safety components (basic safety investment and voluntary safety investment) might improve safety performance. The results of the current study can be used as a basis by the contractors and construction companies to invest in safety and to determine proper budget for managing safety of construction projects.

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Introduction: Comprehensive and reliable performance evaluation of organizations has always been one of the main concerns of stakeholders and managers of organizations. Performance evaluation can raise awareness of the progress made in improving the performance of any organizations, especially in the field of health, safety, and environment (HSE) and thus, create the necessary motivation and opportunity to improve the quality of HSE performance. National quality awards and excellence approaches emphasizes the fact that survival in global competition requires improving the performance of organizations on a global scale. The EFQM enterprise excellence model, as a comprehensive tool with a comprehensive approach to all aspects of organizations, helps managers to understand their organization well.
Material and Methods: This study was conducted in Tehran Industrial Group in 2018, during which the performance of this industrial group in the design and construction of one of the dams in the south of the country was evaluated and analyzed. The data collection tool was a standard self-assessment questionnaire based on the EFQM enterprise excellence model, the validity and reliability of which was tested by Cronbach’s alpha coefficient at 0.971.
Results: In terms of “enablers” criteria, the leadership dimension, with a score of 76.36, obtained the best percentage of scores, while the processes criterion with a score of 72.04 had the lowest percentage of scores. This dimension, along with staff, resources, and partnership dimensions, needs to be improved. In the field of “results” criteria, the key performance results with 79.77 points had the best percentage and the customer result dimension with a score of 69.13 had the lowest, indicating that the organization should improve these sectors.
Conclusion: The results indicated the suitable status of the organization in terms of the criteria of excellence model. The results of this model are generally used for systematic analysis of the organization in order to achieve a comprehensive view of the organization and its challenges.

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Introduction: Phytoremediation is one of the available techniques for removing the volatile organic compound from the air. Benzene and toluene are volatile organic compounds that exist in many occupational environments. Plants are able to reduce benzene and toluene in the air and the use of plants is a simple and consistent solution for the nature to reduce these compositions in the air and improve the air quality of work environments. The phytoremediation potential of Dannae racemosa and Hedera helix were evaluated for remediation of benzene and toluene in air.
Material and Methods: Dannae racemosa and Hedera helix  were exposed to exposed benzene(250ppm) and toluene(250ppm) each time alone in a chamber and to examine the decrease amount of benzene and toluene during 6 days. Then plants were exposed to 250ppm and 250ppm of benzene three times with a rest day and the processes of reduction were investigated.
Results: Dannae racemosa was able to remove all of benzene and toluene concentrations from the air after 6 days. Hedera helix was able to reduce all of benzene and toluene concentration from the air after 6 and 5 days, respectively. The differences in Benzene and toluene remediation were assessed between the first and the third subsequent exposure and the results showed that the reduction rate increased for Dannae racemosa.
Conclusion: It can be concluded that the Dannae racemosa and Hedera helix could be used for benzene and toluene phytoremediation.

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Introduction: Toluene is considered as a group of chemical contaminants, causing problems for people’s health. Due to the high rate of evaporation and rapid emission in the surrounding environment, it leads to the exposure of many employees and people at risk and, subsequently, its irreparable effects on their health in different jobs. Therefore, its removal is very important. In the present study, this contaminant was removed using the copper metal-organic framework (MOF) under different operating conditions. 
Material and Methods: In this study, the copper MOF was synthesized using the one-pot and in situ method. Physical and morphological properties of the adsorbent were investigated using BET, XRD, FTIR and SEM techniques. The efficiency of the adsorbent in removing toluene from the air stream under the dynamic adsorption system was investigated by examining the effect of the variables of adsorbent mass, pollutant concentration and humidity. Isotherm, thermodynamics and kinetics equations were used to evaluate the data.
Results: The results of experiments determining the properties of the metal-organic framework showed the formation of pure Cu-BDC crystals with mean and particle size distribution of 1.95 nm. The specific surface area calculated by the BET method for the mentioned sample was 686 m2 g-1 and the total volume of structural pores was 0.335 g3 cm3. The presence of micropores increased the dynamic adsorption capacity of toluene. The findings follow the Langmuir isotherm model and the Pseudo-second order kinetic model. Based on the results of thermodynamic studies, entropy change (ΔS°) and enthalpy change (ΔH°) were equal to -0.44 kJ mol-1 K-1 and -15.67 kJ mol-1, respectively. Gibbs free energy change (ΔG°) was also calculated negatively, indicating that the adsorption process was spontaneous and exothermic. The regeneration of the adsorbent was 77% after three cycles.
Conclusion: According to the results of this study, the microporous copper MOF can be used as a result of cheapness, high access, high adsorption capacity and appropriate regeneration rate in different operating conditions for adsorption of toluene.

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Introduction: Labor is one of the most important wards of hospital, where human error is high. Midwifery errors in the maternity ward and in the delivery can be a serious threat to the health of the mother and the infant, resulting in increased treatment costs. Factors affecting human error are diversity in work, high workload, and fatigue. Therefore, this study aimed to evaluate the midwifery errors in the maternity ward using the systematic human error reduction and prediction approach (SHERPA) technique.
Material and Methods: This cross-sectional study was conducted in 2019, during which different midwifery tasks were determined in four stages of admitting, pre-labor, delivery, and postpartum. Tasks and sub-tasks were identified using the hierarchical task analysis (HTA) technique and human error was evaluated using the SHERPA technique.
Results: The results of the HTA technique identified 19 main tasks, 52 sub-tasks, and 114 activities. After assessing human error risk with the SHERPA technique, the performance was the most frequent type of  error and the highest frequency was related to the undesirable risk level.
Conclusion: The errors of the midwifery profession in the hospital’s labor are high-risk and largely critical. Factors such as high workload, time pressure, and fatigue influence the incidence of human error. In order to reduce human error in this area, strategies such as reducing staff workload, developing standard checklists and guidelines are essential to reduce human error in this ward.

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Introduction: 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.
Material and Methods: 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.
Results: 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.
Conclusion: 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.

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Introduction: 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.
Material and Methods: 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.
Results: 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.
Conclusion: 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.

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Introduction: Studies show that in many cases, environmental hazardous agents such as heat, noise, as well as chemical pollutants cause adverse health effects through the mechanism of oxidative stress. This study has examined the effect of exposure to noise and whole-body vibration (WBV) on some parameters of oxidative stress (enzyme superoxide dismutase (SOD), total antioxidant capacity (TAC), and malondialdehyde (MDA)) of workers in a foundry industry.
Material and Methods: The workers were selected based on the calculations related to the sample size and taking into account the inclusion criteria as well as completing the informed consent form. The level of exposure to noise and WBV was measured according to ISO 9612 and ISO 2631, respectively. For each worker, the time-weighted average was calculated. The level of exposure of workers to the studied stressors was divided into three categories: low, medium, and high. The blood samples were taken from all participants between 7-9 am. Then, via ELISA method according to the protocol of the kit manufacturer, the samples were prepared and analyzed. Univariate analysis of variance was performed to determine the “effect size” of each physical stressors on the studied parameters.
Results: The mean levels of MDA, SOD, and TAC among participants were 22.48 (11.19) nmol / ml, 61.28 (10.97) U / ml, and 1.64 (0.90) mM, respectively. Among the exposure variables, noise had the largest effect on MDA level (B = 0.090), which was not statistically significant (P = 0.865). WBV had the largest effect on SOD level (B = -1.469) which was statistically significant (P = 0.016). None of the studied variables had a significant effect on the TAC level; however, among the exposure variables, the greatest effect was related to WBV (B = -0.077; P = 0.133).
Conclusion: The effect of noise on oxidative stress parameters was not statistically significant. The effect of whole-body vibration on oxidative stress parameters except SOD was not statistically significant. Noise and WBV had increasing effect on MDA and decreasing one on SOD and TAC levels.

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Introduction: Universities play a key role in creating a knowledge-based society and its sustainable development. Strategic planning by strategically analyses internal and external environments of the organization, forecast its future, identifying its strategic direction, and strengthening organizational structures, processes, and outcomes, creates and sustains competitive advantages. This study aimed to formulate a strategic plan for the Occupational Health Engineering (OHE) department of School of Public Health (SPH) at Tehran University of Medical Sciences (TUMS).
Material and Methods: In this participatory action research, a strategic planning committee was formed. The strategic planning committee used the strength, weakness, opportunity and threat (SWOT) matrix to evaluate the internal and external environments of the OHE department. Then, the mission, vision, values, goals and objectives of the OHE department were defined. Finally, the operational plan including actions to achieve the goals and objectives were formulated.
Results: Experienced professors and staff, specialized laboratories, professional journals, and high ranked postgraduate students were the most important strengths; and theoretical and non-practical courses, lack of educational protocols, poor communication with industries, lack of resources, and low motivation of employees were some of the weaknesses of the OHE department.  The support of senior managers of TUMS, industry liaison council at school and university, facilities of the university faculties, comprehensive research laboratories of the university, capacities of the private sector and increasing the demand for research in the industry were the opportunities. High inflation, political sanctions, the absence of consulting engineering companies and the uncertainty of research priorities of industries were important threats to the OHE department. Therefore, the OHE department is in a conservative strategic position. The strategic direction of the department, including the mission, vision, values and goals, until 2025 was determined. Improving the structures, working processes and performance of the occupational health department were determined as objectives and 81 actions were formulated to achieve these objectives.
Conclusion: The educational departments, schools and universities must have a strategic plan for progress. The strategic plan of the occupational health department of TUMS was formulated in line with the four-year plan of the university and coordinated with the operational plans of the educational, health and research deputies of TUMS and school of public Health. Proper implementation of this comprehensive and evidence-based strategic plan will improve the performance of the occupational health department.

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Introduction: Climate change and hot processes in the workplaces has led to an increase in the effects of heat stress on employed people, which has become a major concern, especially in tropical and subtropical countries. Early detection of biomarkers in induction of heat stress-related DNA damage can be used in the identification and evaluation of health and safety, including occupational health professionals, as well as to prevent serious diseases caused by heat stress in various occupations with the nature of hot processes or to help different warm seasons of the year. Therefore, this review study was conducted to identify diagnostic biomarkers heat stress induced- DNA damage in occupational exposure.
Material and Methods: Databases such as PubMed, Scopus, Google Scholar, and Web of Science were systematically searched to meet the study’s goals. Moreover, references to relevant publications were examined. Finally, suitable articles were selected and analyzed using the inclusion (studies on different occupations, different biomarkers in hot work environments, all articles published without time limit until the end of April 2022 , and English and Persian language)  and exclusion criteria.
Results: The results of search in databases showed that 9234 articles were found in the initial search. After removing duplicate and unrelated articles, 2209 eligible articles were selected. Based on abstract full-text screening, 7166 studies were excluded, and based on abstract full-text screening, 21 studies were not accessible. Finally, seven articles were selected to be reviewed. The evidence showed that diagnostic biomarkers included the measurement of 8-hydroxy-2-deoxyguanosine (8-OHdG), micronuclei semen quality, heat shock proteins (HSP70), and leukocytes were extracted to heat stress induced- DNA damage in occupational exposure.
Conclusion: Based on a review of studies,  biomarkers identified are suitable for heat stress induced- DNA damage as a result of occupational exposure to extremely high heat climate conditions. Understanding and identifying appropriate biomarkers in inducing DNA damage can help health and safety professionals determine the amount and magnitude of heat stress responses in occupational exposure to different temperatures and take appropriate measures and interventions to control and reduce the hazard effects of thermal stress. This study can also be considered as a preliminary study for research in the future.

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Introduction: In recent years, the manufacture of air purification media, especially nanofiber filters using polymeric materials and the electrospinning method, has received much attention in air pollution control. The production of high-performance media and low-pressure drops is an important issue in air filtration. This study aimed to investigate the feasibility of fabricating electrospinning polyethylene terephthalate (PET) media to abduct submicron and micron particles from the air stream.
Material and Methods: To determine the optimal device conditions in the manufacture of PET media, different weight percentages of a PET polymer solution in a mixture of trifluoroacetic acid and dichloromethane solvents (70:30) were first prepared in a pilot study, and various parameters of the electrospinning device were examined and analyzed along with performing the electrospinning process. The surface and morphological characteristics of the media were evaluated using SEM. The pressure drop and efficiency of particle trapping were assessed using a mask and media pressure by a pressure drop test device.
Results: The optimal electrospinning conditions of the PET polymer solution were obtained at a concentration of 20%. The average diameter of nanofibers PET was 163 ± 600 nm with a pressure drop of 26.33 ± 5.5 pa, and average efficiencies of 97.42 ± 1.67% and 99.85 ± 0.21 were obtained for submicron and micron particles, respectively, with a quality factor (QF) value of 0.1740.
Conclusion: The produced media can abduct and remove particles from the air stream for submicron and micron particles in ranges of 96-99% and 99-100%, respectively, with an average pressure drop of 26.33±5.5 pa.

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Introduction: This study quantitatively analyzed the fire risk using the Fire Risk Index Method: Multistorey Apartment Buildings (FRIM-MAB) method, considering the importance of fire safety in student dormitories as human gathering centers and previous limited studies.
Material and Methods: This descriptive-analytical study was conducted on 17 sections of the Qazvin University of Medical Sciences student dormitory in 2021. This study used the FRIM-MAB version 2.1. In this method, 17 parameters and their sub-parameters affecting the fire risk index were determined and weighted. Consequently, the studied dormitory was also inspected, the weighted degree of each parameter was computed, and the fire risk index for each section, which ranged between 1 and 5, was determined.
Results: The average fire risk index of the dormitory building at the time of the study was 2.37. The laundry room received the lowest risk index (1.69), while the computer site received the highest risk index (2.7). The results indicated that the most effective parameters causing fire risk were related to “compartmentation” (12 frequency items), “linings in the apartment” (4 frequency items), and “escape routes” (1 frequency item). These parameters contributed more than 42% to create the risk index for the dormitory’s most dangerous areas.
Conclusion: The FRIM-MAB method is a suitable quantitative and indexing fire risk assessment method for student dormitory buildings, and it is a quick, inexpensive, and effective screening and ranking tool. Periodically evaluating the dormitory’s fire risk and, if necessary, improving the environment is essential. In the present study, compartmentation, linings in the apartment, and escape routes were the most effective parameters in fire risk of the studied dormitory.

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Introduction: The important parameters for evaluating the performance of particle filtering respirators in international standards are the filtration efficiency and respiratory resistance of the mask filter against airflow passage. To improve nanofiber filtration efficiency while creating the least breathing difficulty for the wearer, various research has been or is being conducted worldwide. This study investigated the effect of using polyacrylonitrile (PAN) nanofiber composite membrane and montmorillonite clay nanoparticles (MMT) in enhancing particle-filtering respirators’ filter performance, achieving higher filtration efficiency while maintaining optimal respiratory resistance conditions.
Material and Methods: First, PAN polymer solution containing zero, 1%, 2%, 3%, and 5% MMT nanoparticles was prepared, and then PAN/MMT nanofiber composite membrane was synthesized in an electrospinning machine. Filtration efficiency was measured in diameter range of 0.3, 0.5, 1, and 3 microns using sodium chloride aerosol. Additionally, filter breathing resistance was measured at flow rates of 30, 85, and 95 liters per minute.
Results: The efficiency of synthesized composite nanofilters for particle purification can be improved by adding MMT nanoparticles to PAN nanofibers. Optimal MMT concentration was found to be 2%. This addition resulted in an increase in filtration efficiency for particles with sizes of 0.3, 0.5, 1, and 3 microns by 4.2%, 4.88%, 3.77%, and 2.75% respectively without causing significant difference in respiratory resistance. Improved filtration efficiency can be attributed to enhanced morphology of composite nanofilters resulting from addition of MMT nanoparticles. Adding 2% MMT nanoparticles to PAN nanofibers resulted in uniform distribution and smaller fiber dimensions which did not significantly affect Packing density and porosity.
Conclusion: If 2% of MMT nanoparticles are added to PAN nanofibers and used to produce particle respirators, resulting respirator will exhibit a 4.2% increase in particle filtration efficiency without increasing breathing difficulty for user. This result can help protect users from particulate pollutants in air pollution conditions.