فهرست مطالب غلامرضا فرید فهیمی

One of the most significant human health risks is the pollution of enclosed spaces. The high density of people and the variety of products available in exhibition halls make them perfect locations for the accumulation of polluting particles. Air pollutants are mixtures of suspended solids and liquids in the air, which vary in size, shape, and chemical composition.This study was conducted to measure PM2.5 and PM10 pollutants particles in four seasons consecutively throughout the year in Hall No. 38 of the Tehran International Exhibitions Company (TIEC). This goal was achieved by establishing an (SKC) air sampling pump at breathing height and comparing the results with the standard 24-hour analysis. According to the results, the average PM10 value in the autumn season was 160.8 µg cm-3, which was reported as higher than the standard 24-hour exposure value. There was also a maximum measured value of 198 µg cm-3 of PM10 during the mentioned season. The findings showed that the average PM2.5 value in the same season was 38 µg cm-3, which was reported as higher than the standard 24-hour exposure value (35 µg cm-3).It was mainly the effect of outdoor air quality on the indoor air in halls and the heating system that contributed to the increase in particulate matter in the autumn. According to the studies, it was found that outdoor and indoor air in halls is directly related. Therefore, Tehran Exhibition halls and other similar sites should continually monitor the level of air pollutants to reduce their health effects.

The purpose of the present study was to assess the concentration of Cd, As, Cu, and Zn metals in water and sediments of rivers in the west of Mazandaran province, Iran. The number of water and sediment samples was 36 taken from four stations from April 2019 to March 2020 and analyzed with three replicates. Mean values of total environmental factors at the four stations during winter and summer seasons were as T=11.21-16.46 °C, salinity=3.58-6.47 g/l, pH=5.42-5.92, TDS=3.52-6.25 g/l, electrical conductivity=6.27-11.12 μmho/cm, nitrite=0.01-0.03 mg/l, and nitrate=1.37-3 mg/l respectively. The quality of environmental factors was found within the normal range for water quality in Iran for different types of land use: agricultural, industrial, recreational, and hot-and cold-water fish farming. Mean values of total adsorption of cadmium, arsenic, copper, and zinc were 0.25, 0.77, 11.44, and 11.02 mg/l respectively in water samples, and 0.2, 3.83, 20.91, and 59.27 μg/g in sediment samples. The adsorption of all metals was higher at the beginning of the cultivation season compared with the non-cultivation season both in water and sediment samples. Safarood river was the most polluted of all rivers. The concentration of metals was higher than the permissible limit in water, but lower in sediments (except for copper and arsenic) in all four rivers.