Aim: Due to the importance of the relationship between air pollutants and the incidence of many diseases in polluted cities, in this study, we collected the data related to yearly, seasonally, monthly, daily, and hourly concentrations of particulate matter (PM) _2.5, PM₁₀, sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and ozone (O₃) recorded at four monitoring stations across Karaj city, Iran, to investigate the air pollutant trends based on air quality indexes (AQIs) in the city during 2012–2018. Materials and Methods: The correlations between PMs and gaseous pollutants were analyzed using the Pearson correlation coefficient. The concentrations of air pollutants indexes including O₃, NO₂, SO₂, CO, PM₁₀, and PM_2.5 were recorded in four air pollution monitoring stations in Karaj obtained from the monitoring system of the environment department. Then, the data were analyzed using SPSS and Graph pad softwares. Results: The findings showed that in 20%–40% and 1%–5% of days during 2012–2018, higher concentrations of PM_2.5 and PM₁₀ were experienced than the national standard (NS) concentration, respectively. Furthermore, during this time, 0.3%–0.9% of days indicated the higher concentrations of CO and SO₂ than the NS, respectively. Although the daily concentration of NO₂ was lower than NS, 0.5%–5% of days were exposed to the higher concentration of O₃ than NS. SO₂ concentration showed a negative and positive correlation with PM₁₀ (r = −0.69, P = 0.013) and O₃(r = 0.58, P = 0.03), respectively. Conclusion: These results indicated that Karaj AQI was moderate and the most problem with air quality in Karaj city was attributed to the PM_2.5 concentrations. To reduce health disorders related to this pollutant, it is necessary to control PM_2.5 sources and sensitive groups should reduce outdoor activities.

Aims: This study aimed to evaluate the management of hospital wastes with an emphasis on genotoxic waste. In this regard, wastes production rate, separation method, temporary storage, collection, and disposal were investigated. Materials and Methods: A comprehensive survey was conducted at six public hospitals by designing a questionnaire regarding medical waste management. Furthermore, face-to-face interviews were arranged. Results: The results demonstrated that the generation rate of total medical waste, hazardous-infectious waste, genotoxic waste, and the generation rates of general waste in Semnan city were 2.904, 0.9 (31%), 0.09 (3%), and 1.914 (66%) kg/bed-day, respectively. Approximately 50% of the hospitals used unsuitable containers to collect genotoxic wastes from hospital wards. It was found that all the hospitals have temporary storage rooms. However, there is not a specific and separate temporary storage place for genotoxic wastes in the hospitals. Four hospitals (83.3%) are equipped with steam sterilization and shredding equipment. One hospital (16.7%) has steam sterilization without shredding for treating infectious and sharp wastes. In this study, chemical neutralization was considered the principal method for treating genotoxic waste in hospitals. Moreover, lack of staff training (46% of hospitals) and shortage of personal-protective equipment (85% of hospitals) were considered significant problems in these hospitals. Conclusions: This study revealed that the healthcare waste management index is acceptable for all types of hospital wastes except for genotoxic waste. Therefore, it is essential to pay more attention to the on-site collection and safe storage of genotoxic wastes. Furthermore, in terms of treatment, transfer, and disposal stages, general hospital waste was managed properly compare to genotoxic waste.

Aim: Cognitive function factors have been reported as an effective factor in the incidence of traffic accidents. The aim of this study was to investigate the effect of heat stress on the cognitive performance parameters of taxi drivers. Materials and Methods: This prospective cohort study was performed on 29 taxi drivers in both winter and summer. The parameters studied in this study were precision, speed of work, attention, short-term auditory memory, concentration skills, mental fatigue, the wet bulb glob temperature index, and the thermal comfort parameters. Results: The mean and standard deviation of drivers age was 52.24 ± 8.28 years. People's performance in terms of speed, precision, number of errors, and attention in the summer morning shift was better than the winter evening shift, but these parameters dropped sharply in the evening shift in the summer. There was a statitistically significant difference between these parameters in the morning and evening of summer (P < 0.05). Conclusion: The results of this study showed that heat stress reduces the precision, speed of work and attention and increases the number of errors and mental fatigue of drivers. Therefore, it is necessary to plan to improve the working conditions of drivers to prevent the reduction of drivers' cognitive performance and improve driving conditions.