Iranian Journal of

Background and Objective: Air pollutants and noise level are areas of concern for public health, especially in metropolitan areas. In tunnels, underground stations and indoors with insufficient ventilation rate and noise reflection, accumulation of pollutants and noise pollution are serious problems.
Materials and Methods: The present study was conducted to evaluate the level of PM and noise level in the Majlesi terminal, located close to Imam Ali Square in Isfahan. Sampling was done in two phases, spring and summer. Samples were taken during six working days, twice a day, morning and afternoon and at traffic peaks. The effect of launching a BRT system was also evaluated. The SKC sampling pump and sound level meter of KIMO were used for the evaluation of particulate matter and noise.
Results: The results showed that the launch of a BRT system led to a change in PM concentration from 85.17 μg/m³ to 53.58 (37% reduction), however, the average value of summer noise level (78.34 dB) was higher than the average value of spring (76.23 dB). Both PM and noise levels were higher than the values of international standards of EPA and WHO guidelines. The level of PM and noise level was a function of traffic and varied during weekdays. On Thursdays and after medieval holidays, the highest level was observed. The pollution and noise levels were higher during afternoon than the morning peak hours due to the traffic and accumulation of contaminants.
Conclusion: The research revealed that indoor and underground environments are not suitable options as a parking lot or bus terminals, due to a need for mechanical ventilation, lack of adequate air circulation and sound reflection.
 

Background and Objective: Climate change in recent years has led to a crisis of drought in many countries around the world, including Iran. In such a situation, the supply of safe drinking water is very important and knowing the climate impacts on the chemical quality of these resources can play a significant role in their proper exploitation.
Materials and Methods: Using GIS geomorphology models, the effect of climatic factors including minimum and maximum temperatures, mean precipitation, evaporation, transpiration and vegetation index on the quality of groundwater resources of Varamin Plain include pH, electrical conductivity, total dissolved solid, anions and cations concentrations and total hardness were studied and their maps were produced. Correlation between these factors was investigated using spatial correlation analysis tool at a confidence level of 0.95 (p = 0.05).
Results: The results showed that these parameters (except pH) along the plain are highly variable and the spatial distribution of data in this region is not normal around the mean, and the frequency of pixels with values ​​less than the spatial mean of the region is higher. Spatial distribution of the factors showed that their amounts (except pH) are low in the central area of ​​the plain and reach its peak in the western and northwest regions. The spatial distribution of pH was almost uniform in all the plain.
Conclusion: Correlation analysis showed that the quality of water resources is influenced by climatic factors and the maximum temperature has the highest impact.
 

Background and Objective: This research tries to analyze the spatial distribution and trend of arsenic level changes in the underground water resources of the Sirjan basin, and also to evaluate and analyze the factors affecting the concentration of this element in these water resources.
Materials and Methods: Sampling of underground water sources in the study area was done by systematic-random method and arsenic concentration was done by ICP-MS method in the laboratory. Also, to evaluate the factors affecting the concentration of arsenic in the underground water resources of Sirjan bathe sin, the method of land systems analysis was used.
Results: The results of the research show that the amount of arsenic in all samples is higher than the Guidelines provided by the World Health Organization so the amount of this element in the underground water sources of the study area varies between 30 and 390 µg/L. Samples No. 9, 13, and 16, which are located in the deepest parts of the basin, have the highest amount of arsenic. For this reason, the durability of water in this part of the basin increases. This reduces the intensity of the current. As a result, according to the cumulative effect law, this process can lead to an increase in arsenic concentration.        
Conclusion: The evaluation of changes in the concentration of arsenic in the underground water resources of the study area indicates that the concentration of this element had a high increasing trend. According to the results, the location of the studied area in the center of hydrothermal and geothermal processes (copper mineralization belt in Iran), the cumulative effect, and the effect of pH on the absorption and desorption of arsenic are among the most important factors affecting the increase of arsenic in the underground water resources of Sirjan Basin.