Establishing research impact assessment in Iran: The first report from a non-high-income country.

Background: This study presents the first report on research impact assessment (RIA) in non-high-income countries, undertaken as a pilot initiative in 2021. Within it, we aimed to explore the feasibility of employing the 'payback' model for evaluating the impact of health research and enhancing the accountability of universities. We focussed on three key impact domains: 'production of decision support documents and knowledge-based products,' 'implementation of research results,' and 'health and economic impact.' Methods: We adopted a case study approach to assess the impact of 5334 health research projects conducted by researchers from 18 universities from 2018 to 2020. Researchers were required to submit evidence related to at least one of the specified impact domains; six scientific committees verified and scored claimed impacts at the national level. Results: Only 25% of the assessed projects achieved impact in at least one domain, with the production of decision support documents and knowledge products being the most reported impact. Notably, economic impact was verified in only three projects, indicating room for improvement in this area. Technology research exhibited the highest acceptance rate of claimed impact, suggesting a positive correlation between technology-focused projects and impactful outcomes. Conclusions: This study demonstrates the feasibility of employing a case study approach and the 'payback' model to evaluate the impact of health research, even within the constraints of a moderately equipped research infrastructure. These findings underscore the potential of integrating RIA into the governance of health research in Iran and other non-high-income countries, as well as the importance of using RIA to assess the accountability of health research systems, guide the allocation of research funding, and advocate for the advancement of health research. The study sets a precedent for future assessments in similar contexts and contributes to the ongoing global dialogue on the societal impact of health research.

White Noise and Its Potential Applications in Occupational Health: A Review.

Background: White noise (WN), because of its unique behavior and characteristics, has different applications in different sciences. Nevertheless, the results of studies and reviews of the literature on occupational safety and health found that this type of noise is often used as a noise source to assess the effects of hearing and its physical characteristics. Its possible applications in this area have not received as much attention. The present review study aimed to answer the question, "Can WN be used as a means of promoting occupational safety and health at the workplace?". Methods: In this review, we reviewed the articles published in reputable databases from 1990 to 2020. Our study included 33 articles from 120 that were searched in full text and followed the inclusion and exclusion criteria. Results: Various applications were examined, including noise masking, white noise therapy, cognitive functions, and sleep. WN can enhance the work environment and meet occupational safety and health objectives based on the study's results. The results of this study will provide a basis for continuing research into the use of WN in the workplace as an engineering and management control method. Conclusion: WN is being used in various fields that may hold promise for its application in occupational health sciences and maintaining the well-being of workplace workers.

Investigating the effect of workwear textile modification with nanometal-embedded PMMA polymer by a spray method on textile air permeability, bending stiffness and surface temperature induced by near-infrared.

Objectives. This study aimed to optimize modification of cotton-polyester textiles of workwear in terms of air permeability (AP), bending stiffness (BS) and near-infrared (NIR) reflectance using nanometal-embedded polymethyl methacrylate (PMMA) polymer by a spray method. Methods. This experimental study was carried out to modify cotton-polyester textiles using nanoparticles of aluminum oxide (Al2O3), tin oxide (SnO) and zinc oxide (ZnO) embedded in PMMA polymer with different weight percentages by a spray method under 215-psi pressure. The surface temperature of the textiles induced by the NIR spectrum and their comfort in terms of AP and BS were measured according to Standard No. ASTM D737 and BS 3356, respectively. Results. Cotton (65%)-polyester (35%) textiles can be modified with a PMMA-based aluminum and zinc nanoparticle composite with equal weight percentage using a pressurized spray method with good durability. Also, most NIR reflection is in the textile coated with aluminum and ZnO nanoparticle composite in the PMMA base. Conclusions. It is recommended that this composite be used in future studies to impregnate the clothing textile of outdoor workers in hot and arid regions by a spray method under pressure and its effects be investigated on reducing heat stress in these workers.

Effect of heat stress on DNA damage: a systematic literature review.

Thermal stress has a direct effect on various types of DNA damage, which depends on the stage of the cell cycle when the cell is exposed to different climate conditions. A literature review was conducted to systematically investigate and assess the overall effect of heat stress and DNA damage following heat exposure. In this study, electronic databases including PubMed, Scopus, and Web of Science were searched to find relevant literature on DNA damage in different ambient temperatures. Outcomes included (1) measurement of DNA damage in heat exposure, (2) three different quantification methods (comet assay, 8-hydroxy-2-deoxyguanosine (8-OHdG), and γ-H2AX), and (3) protocols used for moderate (31) and high temperatures (42). The evidence shows that long exposure and very high temperature can induce an increase in DNA damage through aggregate in natural proteins, ROS generation, cell death, and reproductive damage in hot-humid and hot-dry climate conditions. A substantial increase in DNA damage occurs following acute heat stress exposure, especially in tropical and subtropical climate conditions. The results of this systematic literature review showed a positive association between thermal stress exposure and inhibition of repair of DNA damage.

Development and validation of an individual job performance questionnaire (IJPQ).

BACKGROUND: Developing reliable tools to tap into all the behavioral dimensions of individual job performance and identifying the right sub-dimensions is necessary for both research and practice. OBJECTIVE: This study aimed at developing and validating an IJPQ that addresses shortcomings of existing questionnaires. METHODS: After a comprehensive systematic literature review, a framework consisting of four dimensions, including task performance (TP), contextual performance (CP), counterproductive work behavior (CWB), and adaptive performance (AP) was structured for measuring IJP. As well, 45 sub-dimensions were identified for measuring IJP's dimensions. Content and face validity were evaluated, and item impact score (IS), content validity index (CVI), Kappa, and content validity ratio (CVR) were calculated. For reliability and confirmatory factor analysis (CFA), 525 workers completed the validated questionnaire and Cronbach alpha and goodness of fit indexes were determined, respectively. RESULTS: Of the 62 items generated to measure dimensions, 53 were approved. Based on item-level CVI, of the 53 items, only 45 items were accepted. Finally, the results of item level CVR led to the extraction of 27 questions to evaluate IJP. The obtained scale level CVI and scale level CVR were 0.91 and 0.68, respectively. Based on the results obtained from 525 Iranian workers, values of Cronbach's Alpha, X2/df, RMSEA, and P-value were in the acceptable range. CONCLUSIONS: Conclusively, a questionnaire containing 20 items was developed and validated for measuring IJP of Iranian worker's culture. The four dimensions of TP, CO, CWB, and AP consisted of 6, 5, 5, and 4 items each, respectively. Overall, IJPQ is a theory-based, reliable, and valid instrument for assessing job performance.

Thermal stress and TiO2 nanoparticle-induced oxidative DNA damage and apoptosis in mouse hippocampus.

Titanium dioxide (nano-TiO2) is used abundantly in various industrial products and novel medical therapies. In addition, the impact of climate change on the health and safety will undoubtedly increase in the future. However, the effects of exposure to these nanoparticles and heat stress on hippocampal DNA damage and apoptosis remain unclear. This study was conducted to evaluate the DNA damage and apoptosis in the hippocampal tissue and the physiological responses in mice induced by intraperitoneal (i.p.) administration of TiO2 nanoparticles (NPs) and heat stress for 14 consecutive days. The results showed that heat stress and TiO2-NPs were induced in the mouse hippocampus that led to hippocampal reactive oxygen species generation, oxidative damage of DNA, and apoptosis in a partly dose-dependent manner, especially at very hot temperature. High doses of nanosized TiO2 and severe heat stress significantly damaged the function of the hippocampus, as shown in the comet assay and apoptosis tests. The results of this study may provide data for appropriate measures to control and assess the risk of nano-TiO2 and thermal stress hazards to human health, especially workers. Safety guidelines and policies should be considered when handling nanomaterials in a hot environment.

Evaluation of the relationship between psychological distress and sleep problems with annoyance caused by exposure to environmental noise in the adult population of Tehran Metropolitan City, Iran.

Purpose: The aim of this study was to investigate the association between the psychological distress and sleep problems with environmental noise annoyance in adult population. Methods: This is a cross-sectional study on 822 adult population of Tehran City in 2016. Integrated cluster stratified random sampling and Kish grid method were used. Noise annoyance, the day-night average sound level (Ldn), nighttime average sound level (Lnight), and daytime average sound level (Lday) were selected as noise exposure indicators. The prevalence of psychological distress and sleep problems were assessed using the Kessler Psychological Distress Scale (K10) and the PSQI questionnaire, respectively. Multiple logistic regression analysis was applied for data analysis. Results: Among the participants 46.03%% were exposed to a sound level higher than the daytime standard level (55 dB) and 84.6% were exposed to a level higher than the nighttime standard limit (45 dBA). According to the results, 49% of the subjects had poor sleep quality and 66% were highly sensitive to noise. In addition, 17.73% had a high risk of mental disorders and 16.48% were found to have a mild risk of mental disorders. There was found a statistically significant association between psychological distress and the noise annoyance at home (OR = 1.3 CI 95% (1.17-1.44)) and at work environment (OR = 1.18 CI 95% (1.08-1.28)). Conclusion: The findings indicated that the study population was highly sensitive to noise. In addition, the relatively high percentage of people who exposed to non-standard levels of sound indicates that this exposure has the potential to cause physical and mental consequences among them.

Burden of diseases attributed to traffic noise in the metropolis of Tehran in 2017.

Although road traffic noise is the most important source of environmental noise emission in large cities, little is known about health burden. The present study was conducted to estimate the burden of diseases attributed to traffic noise in the metropolis of Tehran in 2017. Using noise maps provided by the municipality of Tehran, we calculated population exposure distribution in term of Ldn and Lnight and the number of DALYs lost due to ischemic heart disease, hypertension, high sleep disturbance, annoyance and stroke endpoints based on the World Health Organization Environmental Noise Guidelines for the European Region. We applied published dose-response functions to estimate the traffic noise burden for high sleep disturbance and annoyance. We estimated 61,284 DALYs or 697 DALYs per 100,000 population attributed to traffic noise in Tehran for the reference year 2017. Highly sleep disturbance with a share of 58.74% of the DALYs was recognized as the most important contributor of disease burden, and noise annoyance with a share of 23.12% was ranked next. Ischemic heart disease (11.71%), stroke (5.12%), and hypertension (1.31%) were ranked third to fourth, respectively, in terms of the burden of disease caused by environmental noise. A considerable fraction of the population of Tehran lives in areas with an environmental noise higher than the standard level. The findings showed that traffic noise pollution is an important environmental risk factor in Tehran imposes the greatest burden on the community, mainly through highly sleep disturbance and noise annoyance endpoints.

Development of an observational - perceptual heat strain risk assessment (OPHSRA) index and its validation.

BACKGROUND: The thermal strain can be measured using subjective methods without the use of sensitive equipment. The purpose of the present study was the development and validation of an observational - perceptual heat strain risk assessment (OPHSRA) method. METHODS: This cross-sectional study, in 2019, was performed. At first, an observational-perceptual questionnaire was designed using effective items in producing heat strain. Then, the reliability and validity of the questionnaire were examined. Later, 201 male workers were asked to perform the routine tasks for 90 min under various climatic conditions after resting in a cool room. At the end of the activity, the tympanic temperature of the subjects was accurately measured. Also, the designed questionnaire was completed by researchers and participants. Then, the effect coefficients of the items were calculated and used for developing the novel index. At final, the index validity was investigated. RESULTS: The values of the content validity ratio (CVR), content validity index (CVI), and Cronbach's coefficient alpha (α) of the designed questionnaire with 16 questions were equal to 0.793, 0.913, and 0.910, respectively. The results indicated that environmental, job, administrative, and clothing items assessed by the questionnaire with the coefficients of 0.860, 0.658, 0.783, and 0.566 had significant effects on the thermal strain, respectively. These coefficients were exploited to develop the index. The result revealed that the OPHSRA index justified 69% of the variations of the tympanic temperature (R2 = 0.69). CONCLUSION: The novel index developed by the questionnaire had an acceptable validity. Therefore, this index can be used for estimating the risk of thermal strain in a variety of thermal conditions.

The combined effect of industrial noise type, level and frequency characteristics on hand motor skills: A lab trial study.

BACKGROUND: The study aimed to assess the interactive effects of industrial noise type, level and frequency characteristics on hand motor skills using the Minnesota Manual Dexterity Test and the Hand Tool Dexterity Test. METHODS: A total of ten nonsmoking male volunteers with normal hearing and vision were selected for this study. The study followed a full 3×3×2 factorial design. Independent variables were noise type (steady, intermittent and fluctuating), noise level (75, 85 and 95 dBA) and frequency characteristics ("roar" <2000 Hz and "hiss" >2000 Hz). RESULTS: For Minnesota Manual Dexterity Test, the lowest speed is related to steady hiss noise at 75 dBA and the highest speed is related to fluctuating roar noise at 95 dBA. The speed is being significantly affected by the frequency characteristic (P = 0.041) and noise type (P = 0.025). The effect of hiss noise on speed is greater than roar noise (P = 0.038). There is a significant difference (P = 0.035) between continuous noise and fluctuating noise. For the Hand Tool Dexterity Test, the lowest speed is related to fluctuating hiss noise at 95 dBA and the highest speed is related to steady roar noise at 95 dBA. The speed is being significantly affected by the frequency characteristic (P = 0.002), noise type (P = 0.0001) and noise level (P = 0.005). The effect of hiss noise on response variable to be greater than roar noise (P = 0.008). There is a significant difference (P = 0.0001) between steady noise and the two other types of noise, and also there is a significant difference between 75 dBA and 85 dBA level (P = 0.003). CONCLUSIONS: The results showed that on hand motor skills, speed response was influenced by three characteristics: the type of noise, frequency characteristics and noise level. Also, the effect of the hiss noise was more than the roar noise.

Investigating the role of internal layout of magnetic field-generating equipment on workers' exposure at power substations.

Introduction. This research is an attempt to show the role of interior layout of equipment in generating magnetic fields. Materials and methods. The levels of an extremely low-frequency magnetic field were measured in accordance with Standard No. IEEE 644:1994 in three substations and a control building in a petrochemical power plant in southern Iran. Then, workers' occupational exposure (time-weighted average [TWA]) was calculated and the sources of maximum magnetic field generation at each place were identified. Their interior design was changed to achieve the optimal layout of equipment subsequently; the workers' TWA was recalculated for the new situation. Results. The obtained results showed that electrical engineers and technicians were exposed to the maximum TWA of 10.14 µT. The operators in the control room were exposed to the lowest TWA of 0.84 µT. The results also showed that after the change of interior design and proper layout design of the equipment in the substations, the TWA was reduced by 0.73 µT. Conclusion. The research findings revealed that the most harmonious arrangement of equipment in an industrial unit plays a major role in reducing the exposure of workers to magnetic fields and ultimately increases the level of their health in the workplace.

Modeling heat stress changes based on wet-bulb globe temperature in respect to global warming.

BACKGROUND: This ecological study aims to model the trend of changes in exposure of outdoor workers to heat stress in outdoors in the coming decades with the use of the Wet-Bulb Globe Temperature (WBGT), Hadley Coupled Atmosphere- Ocean General Circulation Model, version 3 (HADCM3), and Long Ashton Research Station Weather Generator (LARS-WG) in Tehran, Iran, considering the climate change and the global warming. METHODS: The hourly values of environmental parameters including minimum and maximum air temperature, relative humidity, precipitation and radiation related to Prakash , Shahriar and Damavand cities were obtained from the Meteorological Organization of Iran. These data were recorded during 1965 to 2015. The climate modeling was done for 2011-2030, 2046-2065, and 2080-2099. RESULTS: The minimum and maximum air temperatures in the different months of the year in the three studied cities show an increasing trend. Our finding shows that the WBGT will be increased by 2099. In Pakdasht, this index will be close to the danger zone in the coming years, especially in 2080-2099. CONCLUSIONS: All the results obtained indicate an increase in risk of heat stress in outdoor workplaces, given the global warming.

Identification, Classification, and Prioritization of Effective Factors in Producing Thermal Strain in Men at Workplaces using Fuzzy AHP Technique.

BACKGROUND: Various factors can affect thermal strain at workplaces. To prevent heat illnesses due to the heat strain, one must identify and prioritize these factors. Therefore, the present study was aimed to determine the relative importance of the effective factors in producing thermal strain in men at workplaces using fuzzy AHP technique. MATERIALS AND METHODS: This qualitative practical study was performed in 2019. Effective factors in producing heat strain were identified by a literature review. Then, an expert panel reviewed the identified factors and omitted some of them. Further, the balance theory of job design was applied to classify the heat strain factors. Later, these factors were categorized into six groups, including environmental, personal, job, clothing, administrative, and lifestyle elements. In the end, the fuzzy analytical hierarchy technique was used for prioritizing the elements and factors involved in each of them. RESULTS: Based on the results, the environmental element had the highest relative weight and priority (0.178). Other priorities were assigned to the job element (0.171), clothing element (0.171), personal element (0.169), administrative element (0.169), and lifestyle element (0.142), respectively. CONCLUSION: In general, the results showed that environmental factors are the most effective ones in producing heat strain. The results of the present study can be helpful in controlling the thermal strain.

Development and validation of an environmental heat strain risk assessment (EHSRA) index using structural equation modeling based on empirical relations.

BACKGROUND: Need to a simple, available, accurate, comprehensive, and valid indicator is felt to assess thermal effects. Therefore, the present study was aimed to develop and validate the environmental heat strain risk assessment (EHSRA) index using structural equation modeling (SEM) based on empirical relations. METHODS: This cross-sectional study was performed on 201 male workers in environments with various climatic conditions. The heart rate and tympanic temperature of the individuals were monitored at times of 30, 60, and 90 min after beginning the work. At these times, values of dry temperature, wet temperature, globe temperature, and air velocity were also measured and metabolism rate and clothing thermal insulation value were estimated. At the end, a theoretical model was depicted in AMOS software and obtained coefficients were applied to develop a novel index. The scores of this indicator were categorized into four risk levels via ROC curves and validate using linear regression analysis. RESULTS: Indirect effect coefficients of the globe temperature, dry temperature, wet temperature, air velocity, metabolism, and clothing thermal insulation variables on the tympanic temperature were computed by 0.77, 0.75, 0.69, 0.24, 0.49, and 0.39, respectively. These coefficients were applied to develop the index. Optimal cut-off points of boundaries between risk levels included 12.02, 15.88, and 17.56. The results showed that the EHSRA index justified 75% of the variations of the tympanic temperature (R2 = 0.75). CONCLUSIONS: The novel index possesses appropriate validity. It was suggested that this indicator is applied and validated in various environments in the next studies.

Development of a personal heat strain risk assessment (PHSRA) index in workplaces and its validation.

BACKGROUND: There is not a comprehensive heat stress index to screen the people susceptible to heat disorders and illnesses in hot workplaces. The present study was aimed to develop a personal heat strain risk assessment (PHSRA) index in workplaces and validate it. METHODS: This cross-sectional study was carried out on 201 Iranian male employees under various thermal conditions. At first, the demographical data of participants were gathered. After that, the heart rate and tympanic temperature of the subjects were carefully measured at times of 30, 60, and 90 min of starting the work. Environmental factors were measured simultaneously. The metabolism rate and insulation value of clothes were also estimated. At the end, a novel index of the heat strain was developed using structural equation modeling in AMOS and validated using linear regression analysis in SPSS. RESULTS: Indirect effect coefficients of personal factors including age, body mass index, maximum aerobic capacity, and body surface area were equal to 0.031, 0.145, - 0.064, and 0.106, respectively. The coefficients of main factors including dry temperature, wet temperature, globe temperature, wind speed, metabolism, and clothing thermal insulation were obtained as 0.739, 0.688, 0.765, 0.245, 0.482, and 0.383, respectively. These coefficients and normalized values of the factors were used to develop a novel index. The total score of the index was categorized into four levels by optimal cut-off points of 12.93, 16.48, and 18.87. Based on the results of regression analysis, this index justifies 77% of the tympanic temperature as a dependent variable (R2 = 0.77). CONCLUSIONS: In general, the results indicated that the novel index developed by the personal and main factors had proper validity in the prediction of thermal strain.

Autonomic Nervous System Responses to Whole-Body Vibration and Mental Workload: A Pilot Study.

BACKGROUND: Whole-body vibration (WBV) and mental workload (MWL) are common stressors among drivers who attempt to control numerous variables while driving a car, bus, or train. OBJECTIVE: To examine the individual and combined effects of the WBV and MWL on the autonomic nervous system. METHODS: ECG of 24 healthy male students was recorded using NeXus-4 while performing two difficulty levels of a computerized dual task and when they were exposing to WBV (intensity 0.5 m/s2; frequency 3-20 Hz). Each condition was examined for 5 min individually and combined. Inter-beat intervals were extracted from ECG records. The time-domain and frequency-domain heart rate variability parameters were then extracted from the inter-beat intervals data. RESULTS: A significant (p=0.008) increase was observed in the mean RR interval while the participants were exposed to WBV; there was a significant (p=0.02) reduction in the mean RR interval while the participants were performing the MWL. WBV (p=0.02) and MWL significantly (p<0.001) increased the standard deviation of normal-to-normal intervals with a moderate-to-large effect size. All active periods increased the low-frequency component and low-frequency/high-frequency ratio. However, only the WBV significantly increased the highfrequency component. A significant (p=0.01) interaction was observed between the WBV and MWL on low-frequency component and low-frequency/high-frequency ratio. CONCLUSION: Exposure to WBV and MWL can dysregulate the autonomic nervous system. WBV stimulates both sympathetic and parasympathetic nervous system; MWL largely affects sympathetic nervous system. Both variables imbalance the sympatho-vagal control as well.

The effect of battery charge levels of Mobile phone on the amount of Electromagnetic waves emission.

PURPOSE: Over the past decades, mobile phone usage have increased dramatically. Extensive development and use of mobile telecommunication services has increased exposure to radio frequency electromagnetic waves (RF-EMW) in the daily lives of humans, and concerns about the harmful effects of mobile phones have also increased on human health. Therefore, this study aimed to investigate the effect of battery charge levels of the mobile phone on electromagnetic waves emission. METHODS: The mobile phone used in the current study was HTC One E9+ (0.181 W/kg SAR) with a non-removable battery model Li-Po 2800 mAh. The power density was measured with the mobile phone set to operate at the 2G mode by a SMP2 Portable Electromagnetic Field Monitoring System. Power density was measured in Calling mode (50 sec), Called mode (40 sec) and Talking mode (360 sec) at the battery charge levels of 1, 5, 10, 15, 20, 30, 50, 60, 70, 80 and 100%. RESULTS: In Calling mode, the maximum electromagnetic waves were determined when the mobile phone had 1% battery charge and also while it was being charged. Contrary to Calling mode, there is no statistically significant difference between the power density emitted in Called mode and Talking mode at the various battery charge levels. Power density was found to be highest in the Called mode (29.11 µw/cm2), and to be higher in the Talking mode (23.005 µw/cm2) than in the Calling mode (10.27 µw/cm2). CONCLUSIONS: The data of the present study can be used to monitor the daily exposure of mobile phone users as well as to estimate exposure levels in the laboratory and non-laboratory studies. As long as a mobile phone that is in the standby mode remains within the geographic domain of the operator's service zone, the power density emitted from that phone will be virtually zero, and any background wave can be attributed to other sources.

Combined effect of whole-body vibration and ambient lighting on human discomfort, heart rate, and reaction time.

PURPOSE: This study aimed to investigate the effect of whole-body vibration and ambient lighting, as well as their combined effect on human discomfort, heart rate, and reaction time in laboratory conditions. METHODS: 44 men were recruited with an average age of 25.4 ± 1.9 years. Each participant was subjected to 12 experimental steps, each step lasting five minutes for four different vibration accelerations in X, Y, and Z axes at a fixed frequency; three different lighting intensities of 50, 500, and 1000 lx were also considered. At each step, a visual computerized reaction test was taken from subjects and their heart rate recorded by pulse oximeter. In addition, the discomfort rate of subjects was measured using Borg scale. RESULTS: Increasing vibration acceleration significantly increased the discomfort rate and heart beat but not the reaction time. Lack of lighting caused more discomfort in the subjects, but there was no significant correlation between lighting intensity with heart rate and reaction time. The results also showed that the combined effect of vibration and lighting had no significant effect on any of the discomfort, heart rate, and reaction time variables. CONCLUSIONS: Whole-body vibration is an important factor in the development of human subjective and physiological reactions compared to lighting. Therefore, consideration of the level of vibration to which an individual is exposed in workplaces subject to vibration plays an important role in reducing the level of human discomfort, but its interaction with ambient lighting does not have a significant effect on human subjective and physiological responses.

Application of Universal Thermal Climate Index (UTCI) for assessment of occupational heat stress in open-pit mines.

The purpose of this article is to examine the applicability of Universal Thermal Climate Index (UTCI) index as an innovative index for evaluating of occupational heat stress in outdoor environments. 175 workers of 12 open-pit mines in Tehran, Iran were selected for this research study. First, the environmental variables such as air temperature, wet-bulb temperature, globe temperature, relative humidity and air flow rate were measured; then UTCI, wet-bulb globe temperature (WBGT) and heat stress index (HSI) indices were calculated. Simultaneously, physiological parameters including heart rate, oral temperature, tympanic temperature and skin temperature of workers were measured. UTCI and WBGT are positively significantly correlated with all environmental parameters (p<0.03), except for air velocity (r<-0.39; p>0.05). Moreover, a strong significant relationship was found between UTCI and WBGT (r=0.95; p<0.001). The significant positive correlations exist between physiological parameters including oral temperature, tympanic and skin temperatures and heart rate and both the UTCI and WBGT indices (p<0.029). The highest correlation coefficient has been found between the UTCI and physiological parameters. Due to the low humidity and air velocity (~<1 m/s) in understudied mines, UTCI index appears to be appropriate to assess the occupational heat stress in these outdoor workplaces.

Weighting Criteria and Prioritizing of Heat stress indices in surface mining using a Delphi Technique and Fuzzy AHP-TOPSIS Method.

BACKGROUND: Heat stress as a physical harmful agent can increase the risk of health and safety problems in different workplaces such as mining. Although there are different indices to assess the heat stress imposed on workers, choosing the best index for a specific workplace is so important. Since various criteria affect an index applicability, extracting the most effective ones and determining their weights help to prioritize the existing indices and select the optimal index. METHODS: In order to achieve this aim, present study compared some heat stress indices using effective methods. The viewpoints of occupational health experts and the qualitative Delphi methods were used to extract the most important criteria. Then, the weights of 11 selected criteria were determined by Fuzzy Analytic Hierarchy Process. Finally, fuzzy TOPSIS technique was applied for choosing the most suitable heat stress index. RESULTS: According to result, simplicity, reliability, being low cost, and comprehensiveness were the most determinative criteria for a heat stress index. Based on these criteria and their weights, the existing indices were prioritized. Eventually, wet bulb glob temperature appropriated the first priority and it was proposed as an applicable index for evaluating the heat stress at outdoor hot environments such as surface mines. CONCLUSIONS: The use of these strong methods allows introducing the most simple, precise, and applicable tool for evaluation the heat stress in hot environments. It seems that WBGT acts as an appropriate index for assessing the heat stress in mining activities at outdoors.