Evaluation of PM2.5 Concentration and Determinant Parameters on its Distribution in Tehran's Metro System in 2012

Objective and Among air pollutants، particles are the primary and major pollutant. Research conducted by World Health Organization (WHO) shows that per each 10 micrograms increase in the concentration of particles، the mortality rate rises 1 to 3 times. The purpose of this study has been to determine the concentration of PM2. 5 and determinants of it distribution in Tehran’s metro stations is autumn and winter of 2012. In this study، concentrations of PM2. 5 in 24 of Tehran’s metro stations were measured during autumn and winter. At each station، samples were taken in 4 spots and 4 times: morning، afternoon، evening and night. For sampling of particles، a portable real-time reading particle monitoring device HAZ DUST EPAM 5000 with a flow of 4 liters per minute was used. Results from measurements were compared with EPA and DOE (Department of Environment) standards. The results showed that max، average and min concentrations of PM2. 5 in underground stations were 103، 49 and 10 µg/m3 respectively، also max، average and min concentration PM2. 5 at ground-level stations were 99، 39 and 8 µg/m3 respectively. The results of this study indicate that the average concentration of suspended particles in Tehran metro stations was higher than EPA and DOE environment standards and air quality in metro stations was inappropriate.