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Long-term exposure to ionizing radiation (IR) can cause dire health consequences even less than the dose limits. Previous biomonitoring studies have focused more on complete blood counts (CBCs), with non-coherent results. In this study, we aimed to investigate the association between exposure to IR and cytokine interleukin-6 (IL-6) along with hematological parameters in Tabriz megacity's radiation workers. In this hospital-based study, blood samples were taken from 33 radiation workers (exposed group) and 34 non-radiation workers (control group) in 4 hospitals. Absorbed radiation dose was measured by a personal film badge dosimeter in radiation workers. The studied biomarkers and all of the selected covariates were measured and analyzed using adjusted multiple linear regression models. The exposed doses for all radiation workers were under the dose limits (overall mean = 1.18 mSv/year). However, there was a significant association between exposure to ionizing radiation and IL-6 (49.78 vs 36.17; t = 2.4; p = 0.02) and eosinophils (0.17 vs 0.14; t = 2.02; p = 0.049). The difference between the mean of the other biomarkers in radiation workers was not statistically significant compared to the control group. This study demonstrated that long-term exposure to ionizing radiation, even under the dose limits, is related to a significantly increased level of some blood biomarkers (Il-6 and eosinophil) that, in turn, can cause subsequent health effects such as cancer.

Introduction: The nature of firefighters’ work is characterized by its unexpected emergencies, sleep deprivation, night shift schedules, and smoke exposure during firefighting. Methods: Eighteen firefighters were involved in simulated live-fire activities. Firefighters’ health status in terms of cardiovascular and mental conditions was checked by a physician and through reviewing their medical records. Firefighters’ cognitive functions were evaluated by visual and auditory continuous performance tests (VCPT and ACPT) and paced visual and auditory serial addition tests (PVSAT and PASAT). Results: VCPT and ACPT scores were lower after the activity relative to baseline. The results revealed that ACPT appears to be more difficult than VCPT. Also, PVSAT and PASAT scores decreased significantly after the experiment. PASAT scores following firefighting tasks experienced a more significant decline compared to those of the PVSAT. Conclusions: These findings suggest that firefighters have visual and auditory cognitive function problems following firefighting activities. In conclusion, auditory cognitive function was more influenced than the visual ability as a result of the experiment.

Thermal comfort is a subcategory of environmental comfort measured in the light of climatic conditions. Having a good climate is regarded as an advantage for any tourist attraction. The present study aimed at assessing thermal comfort of tourist attractions in Kerman. This cross-sectional descriptive-analytical study used ISO 7730 to evaluate thermal comfort in Kerman through both subjective and objective procedures. Data were collected on three different days of the six months of summer and winter. Three time intervals (8–9 AM, 11–12 PM, and 6–7 PM.) were set for data collection on each day. The results indicated that subjective and objective PMV had the highest correlation with dry temperature (r = 0.88 and r = 0.94, respectively). There was also a significant correlation between objective and subjective PPD (r = 0.91) and objective and subjective PMV (r = 0.97). According to the obtained results, subjective PMV is greater than objective PMV. In other words, subjective dissatisfaction is greater than objective dissatisfaction. Furthermore, according to the obtained values for subjective and objective PMV, thermal comfort is at the maximum level at 6–7 PM (during summer) and 11–12 AM (during winter). Policy makers should plan to attract a larger number of tourists in these times.

The current study aimed at comparing the correlation coefficients between wet-bulb globe temperature (WBGT) and a number of parameters, including the discomfort index (DI), modified discomfort index (MDI), predicted mean vote (PMV), predicted percentage of dissatisfaction (PPD), predicted heat strain (PHS), physiological strain index (PSI) and physiological strain index heart rate (PSIhr). In total, 30 workers of a pelletizing factory participated in this study. Environmental parameters and workers' physiological parameters were measured in 10 working stations. The results showed that effective WBGT (WBGTeff) strongly correlates with DI, MDI, PMV, PPD, PHS, PSI and PSIhr. WBGTeff had the highest correlation coefficients with PMV, MDI, PHS and PSIhr. Based on the obtained results, it was concluded that heat stress exceeded the standard limit for a number of indices in some of the working stations. Thus, some controlling measures should be taken to reduce heat stress in these stations.

Heat stress negatively influences human health and performance, and leading to lower efficiency in daily activities. The present study sought to examine the relationship between UTCI, other heat indices (SET, PET, PMV, PPD, and WBGT), and environmental parameters. Daily data, encompassing a 12 month period in 2016 (from 6 a.m. to 9 p.m. for each day), were retrieved from the Meteorological Organization of Kerman. The data were fed into SPSS 20, followed by conducting Pearson product moment correlation and linear regression to find the association between UTCI and other heat indices/environmental parameters. Excel 2016 was also utilized to draw the relevant diagrams. Significant correlations were detected between UTCI and other heat indices (SET, PET, PMV, and WBGT). UTCI also was measurably correlated with environmental parameters like dry temperature (P

Background: Fire service workers often implement multiple duties in the emergency conditions, with such duties being mostly conducted in various ambient temperatures. Methods: The aim of the current study was to assess the firefighters' physiological responses, information processing, and working memory prior to and following simulated firefighting activities in three different hot environments. Seventeen healthy male firefighters performed simulated firefighting tasks in three separate conditions, namely (1) low heat (LH; 29â31°C, 55â60% relative humidity), (2) moderate heat (MH; 32â34°C, 55â60% relative humidity), and (3) severe heat (SH; 35â37°C, 55â60% relative humidity). It took about 45â50 minutes for each firefighter to finish all defined firefighting activities and the paced auditory serial addition test (PASAT). Results: At the end of all the three experimental conditions, heart rate (HR) and tympanic temperature (TT) increased, while PASAT scores as a measure of information processing performance decreased relative to baseline. HR and TT were significantly higher at the end of the experiment in the SH (159.41±4.25 beats/min; 38.22±0.10°C) compared with the MH (156.59±3.77 beats/min; 38.20±0.10°C) and LH (154.24±4.67 beats/min; 38.17±0.10°C) conditions (p0.05). Nonetheless, there was a measurable difference in PASAT scores between LH and SH (p

Background & Aims of the Study: Welder’s exposure to welding fumes can cause occupational diseases. The current study sought to examine exposure to welding fumes among welders who work in the repair shop of Sarcheshmeh Copper Complex and design a local exhaust ventilation system to control exposure to welding fumes. Materials & Methods: This applied analytical study was conducted in the summer of 2016 among welders working in the repair shop of Sarcheshmeh Copper Complex. The study comprised three phases; in the first one, welders’ exposure to welding fumes was assessed at the beginning of the study. After that, a local exhaust ventilation system was designed and installed in the aforementioned repair shop. In the final stage, welders’ exposure to welding fumes was assessed again after installation of the ventilation system. The procedure recommended by NIOSH (method number 7300) was used for individual sampling of welders. Results: Based on the obtained findings, before installing the ventilation system, welding technicians were exposed to 0.3 mg/m3 of copper fumes and 0.04 mg/m3 of chromium fumes. Journeyman welders were also exposed to 2.16 mg/m3 of manganese fumes, while stellar welders were exposed to 6.9 mg/m3 of iron fumes. In the light of these measurements, a local exhaust ventilation system was designed and installed. Subsequently, measurement of exposure to welding fumes showed a significant reduction. That is, welding technicians were exposed to 0.17 mg/m3 and 0.015 mg/m3 of copper and chromium fumes respectively. Additionally, journeyman welders were exposed to 0.86 mg/m3 of manganese fumes, whereas stellar welders were exposed to 4.3 mg/m3 of iron fumes. Conclusions: A comparison of standard limits of exposure to welding fumes and the results obtained from measurements in sampling stations before and after the installation of the local exhaust ventilation system reveals that this controlling measure was very effective in the repair shop of Sarcheshmeh Copper Complex.

Firefighters perform various tasks during firefighting operations under unknown and unpredictable conditions. The present study investigated the impact of firefighting activities and cooling tactics on information processing and work performance. Firefighters performed typical firefighting tasks in the four experimental conditions, namely i) no cooling device (NC), ii) cooling gel (CG), iii) cool vest (CV), and iv) cooling gel and cool vest (CG + CV). The measurement of information processing, Paced Auditory Serial Addition Test (PASAT) scores decreased significantly after the firefighting activities in the four conditions, relative to baseline. The results revealed no significant difference in PASAT scores among the four conditions. However, the performance time (PT) was significantly shorter for the CV and CG + CV compared to the NC and CG conditions. The findings confirmed that the firefighting activities have a detrimental effect on information processing. The CG + CV and CV were more effective than CG and NC in improving PT during firefighting. However, the cooling strategies have a negligible effect on improving information processing performance.

Background: Firefighters often perform multiple emergency tasks during firefighting and life-saving operations under unknown and unpredictable conditions in hot and hostile environments. Therefore, this study examined the effect of cooling strategies on attenuating physiological and cognitive function response during simulated firefighting activities in a smoke-diving room. Methods: Each firefighter engaged in four conditions: namely (1) no cooling device; control (NC), (2) cooling gel containing menthol (CG), (3) cool vest (CV), and (4) cooling gel and cool vest (CG+CV). Cooling effects were evaluated by heart rate (HR), temporal temperature (TT), reaction time (RT), and the correct response (CR). Results: In the four experimental conditions, physiological response increased, reaction time improved, and correct response decreased after the activity relative to baseline. HR and TT were significantly lower at the end of the firefighting activity in the CG+CV (147.47 ± 4.8_bpm; 37.88 ± 0.20_○C) and CV (147.53 ± 4.67_bpm; 37.90 ± 0.22_○C) compared with the CG (153.67 ± 4.82_bpm; 38.10 ± 0.22_○C) and NC (154.4 ± 4.91_bpm; 38.11 ± 0.23_○C) conditions. RT and CR were significantly higher at the end of the activity in the CG+CV and CV compared with the CG and NC conditions. Conclusion: It is concluded that strenuous firefighting tasks have a detrimental effect on firefighters’ physiological responses and cognitive function. The findings also revealed that CV was more effective than the CG in attenuating physiological responses and cognitive function during firefighting operations. Furthermore, combining CV with CG provides no additional benefit. It is concluded that cooling the body by the use of CV offered physiological and psychological benefit for firefighters during simulated firefighting activities.

Introduction: Assessing the work ability and factors affecting it is essential in developing strategies for preventing damages and managing risks. This study aimed to investigate the simultaneous effect of noise level and physiological strain as well as individual characteristics on the work ability. Method: The population in this cross-sectional study included workers of a rubber factory. The TES noise dosimeter was used to examine individual exposure and the electro polar RS100 was used to measure physiological strain index (PSI). Individual characteristics and the work ability index were evaluated using the WAI questionnaire and analyzed using SPSS version 19. chi-square test, pearson correlation coefficient, and one-way and multiple ANOVA were used for data analysis. Results: The final modeling showed that age, exercising period, Equivalent Continuous Sound Pressure Level (Leq), PSI and employment status had significant correlations with the work ability index (p < 0.05). The modified r2 for the obtained model was also calculated to be 0.483. Discussion and conclusion: Based on the findings, number of exercising hours, employment status, age, Leq, and psi are among the factors affecting the work ability index. Use of management and engineering controls are recommended to balance work environments exposed to noise and heat and improve the work ability index. Further, improving employment status due to creating a sense of stability and reducing stress as well as enhancing lifestyle quality can be effective in increasing the work ability index.

Background: Heat is one of the harmful physical factors in the workplace. Occupational heat stress refers to the net load that the workers should put up with as a result of the combined impact of metabolic heat, environmental factors, and clothing causing heat storage in the body. Objectives: This study aimed to compare the correlation between environmental stress index (ESI) and other thermal indices including wet-bulb globe temperature (WBGT), wet-bulb dry temperature (WBDT), thermal work limit (TWL), heat index (HI), standard effective temperature (SET), and physiological equivalent temperature (PET). Methods: Data were collected from 30 workers in one pelletizing factory located in southeastern Iran. The measurement of environmental variables and workers’ physiological responses at the workplace was implemented in 10 conditions. Pearson product-moment correlation coefficient and linear regression were utilized to determine the relationship between ESI and environmental/physiological variables. Results: The results showed that the strongest correlation was recorded between ESI and dry temperature (r = 0.96), natural wet temperature (r = 0.96), and heart rate in the working condition (r = 0.94). ESI was strongly correlated with WBDT (r = 0.99) and WBGT (r = 0.98). Conclusions: It is concluded that ESI is strongly related to heat indices (WBGT, WBDT, TWL, HI, SET, PET, PSI, and PSIHR) and heat stress was higher than the legitimate range in some of the working stations. The highest coefficient was recorded for the relationship between ESI and WBDT.

Introduction: A two-shift work schedule with different rotations is common among firefighters in Iranian petrochemical companies. This study compared salivary melatonin and sleepiness on the last night before turning to day shift at 19:00, 23:00, 3:00, and 7:00 among petrochemical firefighters (PFFs) working seven and four consecutive night shifts. Methods: Sixty four PFFs working in the petrochemical industry were selected. To measure melatonin, saliva samples were taken, whereas the KSS index was used to assess sleepiness. Chi-square and independent samples t-test were carried out to analyze the data, and generalized linear model (GLM) was employed to determine the effect of confounding factors such as lighting and caffeine. Results: The levels of melatonin at 3:00 and 7:00, and the overall changes during the shift in the two shift patterns under the study were different (P < 0.05). Sleepiness was significantly different only at 3:00 in the two studied shift patterns, while the effects of lighting and caffeine on melatonin changes were not significant (P > 0.05). Conclusion: It seems that a slow shift rotation is better because it reduces the secretion of melatonin (hence reducing sleepiness during the night) and changes the peak of melatonin secretion to the daytime, which is a sign of adaptation.

The current study aimed at comparing the correlation coefficients between wet-bulb globe temperature (WBGT) and a number of parameters, including the discomfort index (DI), modified discomfort index (MDI), predicted mean vote (PMV), predicted percentage of dissatisfaction (PPD), predicted heat strain (PHS), physiological strain index (PSI) and physiological strain index heart rate (PSI

This study examined the impact of various types of firefighting activities on firefighters' physiological responses and cognitive function. Each firefighter was engaged in three conditions: (1) Live-fire activities (LFA), (2) Typical firefighting activities (TFA), and (3) Rescue operations at height (ROH). The effects of various types of firefighting activities on the physiological responses and cognitive function were evaluated by heart rate (HR), temporal artery temperature (TT), and the correct response (CR) on a cognitive test. The results indicated that, compared to the baseline, physiological response increased, while information processing performance decreased after the activity. Furthermore, HR and TT were significantly lower at the end of the firefighting activity in the LFA (149.33 bpm; 38.08 °C) compared with the TFA (152.22 bpm; 38.17 °C) and ROH (159.28 bpm; 38.24 °C) conditions. Also, CR was significantly higher at the end of the activity in the LFA and TFA compared with the ROH condition. The results showed that rescue at height was more intensive than the other firefighting tasks in decreasing physiological and cognitive function capacity after the experiment. Practitioner Summary: We assumed that various types of firefighting activities would have different effects on physiological and cognitive functions during firefighting activities. The Findings suggest that rescue at height operations, performed without the use of special protective equipment, was more influential than other firefighting duties in changing firefighters' physiological and cognitive capacity. Abbreviations: CR: correct response; LFA: live-fire activities; TFA: typical firefighting activities; ROH: rescue operations at height; HR: heart rate; TT: temporal artery tempearture; PASAT: pased auditory serila addition teat; FPC: firefighting protective clothing.

This study investigated the combined effect of firefighting operations and exposure to smoke on physiological responses, cognitive functions and physical performance among firefighters. Each firefighter was engaged in two experimental conditions: (a) without artificial smoke, control (NS); (b) with artificial smoke (WS). The results of data analysis revealed that heart rate and body temperature increased significantly after the firefighting activities in the two conditions relative to baseline. In addition, reaction time (RT) and correct response (CR) decreased after the activity relative to baseline and there was a significant difference in RT and CR between the NS and WS conditions. There was also a significant difference in performance time between the NS and WS conditions. These findings demonstrated that a smoke compound has an insignificant effect on physiological responses during firefighting activity. On the contrary, the smoke compound has a detrimental influence on cognitive and physical performance.

Heat is one of the harmful agents in many workplaces. The current study aimed at investigating the correlation between heat stress indices (Universal Thermal Climate Index (UTCI), wet-bulb globe temperature (WBGT), wet-bulb dry temperature (WBDT), Tropical Summer Index (TSI)) and Physiological parameters among mine workers. This cross-sectional study was conducted among workers of one of the mines located in southeast Iran in July–August 2017. Workplace environmental parameters and workers' physiological parameters were measured in thirty different ways from 10 a.m. to 2 p.m. The collected data were fed into SPSS 20 followed by conducting Pearson product moment correlation to detect the relationship between heat stress indices and workers' physiological parameters. Attempts were also made to examine the associations among heat stress indices themselves. The results of data analysis indicated that the mean scores of UTCI, WBGT, WBDT, and TSI were 34.59 ± 1.51 °C, 24.59 ± 0.62 °C, 28.37 ± 0.82 °C, and 31.51 ± 0.7 °C, respectively. On the other hand, the results of Pearson correlation revealed that UTCI and WBDT had the strongest association (r = 0.93, p 0.05). The only statistically significant correlation coefficients were recorded between skin temperature and the two indices of WBGT and TSI. According to the value obtained for UTCI, the workers were exposed to severe heat stress. However, based on WBGT value and ISO 7243 standards for an adapted person, workers were not exposed to heat stress. Keywords: Heat stress, Indices, Physiological parameters, Mine

Background: Firefighters often perform multiple tasks during firefighting operations under unknown and unpredictable conditions in hot and hostile environments. Methods: In this interventional study each firefighters engaged in 4 conditions: namely (1) no cooling device; control (NC), (2) cooling gel (CG), (3) cool vest (CV), and (4) CG+CV. Cooling effects of the employed interventions were evaluated based on heart rate (HR), temporal temperature (TT), reaction time (RT), and the correct response (CR). Results: HR and TT values for use of CG+CV (147.47 bpm [SD 4.8]; 37.88°C [SD 0.20]) and CV bpm (147.53 [SD 4.67]; 37.90°C [SD 0.22]) were significantly lower than the CG (153.67 bpm [SD 4.82]; 38.10°C [SD 0.22]) and NC (154.4 bpm [SD 4.91]; 38.11°C [SD 0.23]) at the end of the activity. RT and CR for use of CG + CV (389.87 ms [SD 6.12]; 143.53 [SD 1.24]) and CV (389.53 ms [SD 6.24]; 143.47 [SD 1.18]) were significantly higher than the CG (385.73 [SD 7.25] ms; 143.07 [SD 0.88]) and NC (385.67 ms [SD 7.19]; 143.00 [SD 0.84]) at the end of the activity. Conclusion: It is concluded that CV was more effective than the CG in attenuating physiological responses and cognitive functions during firefighting operations. Furthermore, combining CV with CG provides no additional benefit.

"Mental workload refers to the amount of effort put in by the mind during the accomplishment of a duty. It essentially has to do with individuals’ mental capacity and the way they receive and process information in order to make decisions and take appropriate actions. The present study aimed at investigating the relationship between mental workload and prevalence of musculoskeletal disorders among welders of Tehran Heavy Metal Structures Company. This cross-sectional descriptive study was conducted in 2016. The sample included 100 welders working at Tehran Heavy Metal Structures Company. Sampling was done by census method. A demographic features questionnaire, NASA-TLX workload questionnaire, and Nordic Questionnaire were used for data collection. Data were analyzed by the use of SPSS (Version 22). Various data analysis procedures, including independent samples t-test, Pearson correlation, chi-square, and Fisher’s exact test, were employed. The mean of participants’ overall score in mental workload was 65.88 ± 21.15. Eighty four percent of the studied welders reported that they had experienced musculoskeletal disorders during the past 12 months (leading to the study), with the highest prevalence being recorded for waist (65%). Furthermore, the results of Pearson correlation indicated that there was a significant relationship between the prevalence of disorders in the legs and physical demand (P = 0.032). Also, a considerable association was observed between disorders in the wrist / hand and overall NASA mental workload score during the past 12 months (P = 0.021). Mental workload and the prevalence of musculoskeletal disorders are relatively high among welders. Waist was the most important risk factor among the participants studied. Future studies should attempt to detect risk factors that cause such disorders and suggest ways to reduce or prevent these problems among welders as much as possible."