Extreme temperature could affect traffic crashes by influencing road safety, vehicle performance, and drivers’ behavior and abilities. Studies evaluating the impacts of extreme temperatures on the risk of traffic crashes have mainly overlooked the potential role of vehicle air conditioners. The aim of this study, therefore, was to evaluate the effect of exposure to extreme cold and hot temperatures on seeking medical attention due to motorcycle crashes. The study was conducted in Iran by using medical attendance for motorcycle crashes from March 2011 to June 2017. Data on daily minimum, mean and maximum temperature (°C), relative humidity (%), wind velocity (km/h), and precipitation (mm/day) were collected. We developed semi-parametric generalized additive models following a quasi-Poisson distribution with the distributed nonlinear lag model to estimate the immediate and lagged associations (reported as relative risk [RR], and 95% confidence interval [CI]). Between March 2011 and June 2017, 36,079 medical attendances due to motorcycle road traffic crashes were recorded (15.8 ± 5.92 victims per day). In this time period, the recorded temperature ranged from −11.2 to 45.4 °C (average: 25.5 ± 11.0 °C). We found an increased risk of medical attendance for motorcycle crashes (based on maximum daily temperature) at both extremely cold (1st percentile) and hot (99th percentile) temperatures and also hot (75th percentile) temperatures, mainly during lags 0 to 3 days (e.g., RR: 1.12 [95% CI: 1.05: 1.20]; RR: 1.08 [95% CI: 1.01: 1.16]; RR: 1.20 [95% CI: 1.09: 1.32] at lag0 for extremely cold, hot, and extremely hot conditions, respectively). The risk estimates for extremely hot temperatures were larger than hot and extremely cold temperatures. We estimated that 11.01% (95% CI: 7.77:14.06) of the medical attendance for motorcycle crashes is estimated to be attributable to non-optimal temperature (using mean temperature as exposure variable). Our findings have important public health messaging, given the considerable burden associated with road traffic injury, particularly in low- and middle-income countries.

Background and aim: Exposure to noise causes auditory and psychological effects in humans. Among the sources of sound generation are the means of transportation, which can cause anger and aggression. The present study was conducted with the aim of investigating the relationship between living in different places in terms of traffic and noise sensitivity with aggression in housewives in Yazd city. Method: This was a cross-sectional study conducted in 2019-2020 among housewives in Yazd city. First, the city of Yazd was divided into three areas with high, medium and low traffic using GIS software, and 100 people from each area, were included in the study in a stratified random manner. Information was collected using Weinstein's bass and Perry questionnaires and sensitivity to sound. Finally, the data was statistically analyzed using SPSS version 24 and R version 4.0.2. Findings: Findings revealed that those who lived in high traffic have a higher aggression score (P-Value=0.009), while no significant difference was observed in the noise sensitivity score among people of different groups (P value=0.071). In addition, a direct and significant relationship was observed between aggression and sensitivity to sound (r=0.28 and P value<0.001). Only two variables of noise sensitivity and place of residence were included in the regression model and (R Square) was equal to 0.096. Conclusion: The results showed that the two factors of traffic load and noise sensitivity have a direct and significant relationship with aggression score among housewives in Yazd city. It is also suggested to use different sound insulation and barriers in buildings.

Background: Drivers of public vehicles, especially in highly polluted and crowded areas, are exposed to high air pollutants, especially particulate matter less than ten microns (PM10). The purpose of this study was to measure and evaluate the level of exposure of city bus drivers to PM10 particles in Bojnurd, Iran. Methods: This descriptive-analytical study was conducted in Bojnurd, Iran. A sampling of particulate matter was taken through bus drivers' respiratory area in two routes from the main routes of the city using the Haz-Dust device. This device has been designed and manufactured based on the NIOSH-500 method. Using an impactor 10, the amount of particulate matter less than ten microns was read from the device.  Particle sampling was performed in both round-trip buses in three shifts in the morning, noon, and evening for one year. The results of the measurements were statistically analyzed by descriptive statistics and mean statistical indices, independent t-test, Mann-Whitney test and One-way ANOVA test at 95% significance level by SPSS software version 24. Results: A total of 420 times, PM10 particles were measured in the drivers' respiratory area.  Approximately 21% of the measurement days had a concentration of more than 150 micrograms per cubic meter of air (or µg/m3). Measurements show that among 140 days of measurement, the highest concentration was on May 21 (with 380.66 µg/m3 of air), and the lowest concentration was on August 9 (with 35.33 µg/m3 of air). The average daily exposure of drivers in this one-year was 151.29 µg/m3 of air. Conclusion: The exposure of city bus drivers to PM10 particles in Bojnurd was much higher than recommended by the World Health Organization (50 µg/m3 of air) and slightly higher than the US Environmental Protection Agency standard (150 µg/m3 of air), which predisposes them to cardiovascular disease in the future. The active buses on these two routes did not use the air conditioning system, which allowed suspended particles to penetrate the bus from the outside. It is suggested that in order to reduce the drivers' exposure, effective control measures should be adopted and implemented as soon as possible, such as launching an air conditioning system equipped with a HEPA filter.

Background: An effective process for preventing industrial accidents basically requires a thorough study of the environment, data collection, evaluation, and analysis of this information, determination of corrective action, and its implementation. Risk management provides an integrated framework for this important process. The purpose of this study was to identify the parameters of the risk management process, combine these parameters by fuzzy logic and construct a fuzzy model to obtain the risk management index and finally design a questionnaire with Likert scale to obtain the inputs of this model to evaluate the risk management process. Methods: This descriptive cross-sectional study was conducted in 2018 in Tehran. First, based on library studies and experts' opinions, Jaques non-linear crisis management model was selected, and based on this model, the parameters of the risk management process were extracted. Then, a questionnaire with 22 questions was designed to measure these parameters, the content and face validity of which were evaluated. Also, to evaluate the reliability of the questionnaire, the test-retest method and Cronbach's alpha coefficient were used. Then the parameters were defined as fuzzy numbers, the Fuzzy inference engine was programmed using fuzzy rules, and its validity was evaluated. Results: The fuzzy model has three stages, in each of which sixteen rules are used. In this fuzzy model, the defuzzification step was performed by four methods with the same results. The designed questionnaire contains twenty-two questions, the content validity ratio (CVR) for this questionnaire is 0.89, and the content validity index (CVI) for all questions was above 0.79. Cronbach's alpha coefficient for this questionnaire was 0.713. Face validity was determined quantitatively by calculating the impact score (more than 1.5). Using intraclass correlation coefficient and Pearson correlation coefficient, the existence of reliability between test times (test-retest) was confirmed, so that their values were 0.84 and 0.88%, respectively. Conclusion: The proposed fuzzy model has a high validity giving a correct evaluation of the risk management process and expressing the final result in the form of an index between zero and one hundred. The risk management process evaluation questionnaire has good validity and reliability with the interpretation that the item has good face validity and is understandable, simple, and fluent for the sample group. Using this tool, industry managers can evaluate the safety risk management process, making them able to identify the strengths and weaknesses of this process, and finally take steps to eliminate the defects and improve this process continuously.

Background and: Industrial noise affects the health of workers and can disrupt the daily communication of workers. The aim of this study is to evaluate occupational exposure and investigate the hearing loss of workers in the two sections of cement mill and material mill of a cement factory in north of Iran. Methods: This was a descriptive study conducted on 52 persons in 2020. At first, the sound measurement was performed with the Casella CEL 450 device in A-weighting network at workers' workplaces based on area-based method. Then, by referring to the medical records and demographic information, the amount of hearing loss in the frequencies of 250-8000 Hz was evaluated. Finally, the results were analyzed using SPSS software version 19. Results: Independent samples T-test showed that the average sound pressure level in the cement mill section (85.50 dBA) is higher than the material mill section (74.38 dBA) (P-value = 0.01). The highest rate of hearing loss was observed at frequencies of 4000 and 8000 Hz. The hearing loss rate was 10 decibels for both ears in the material mill section. No significant difference was observed in the amount of hearing loss in the right and left ears of employees. Conclusion: Noise pollution and hearing loss is common among employees of cement industry. To prevent hearing loss, it is necessary to evaluate and monitor the noise pressure level. Furthermore, engineering measures in the field, using personal protective equipment, as well as adequate training of employees should be conducted.