Population growth, urbanization, changes in people living methods pollution in closed have all caused lots of problems like different kinds of environmental pollution. Nowadays big cities like Tehran are faced with these problems' consequences so intensively that different air pollutants concentrations increase day by day. Air pollution studying includes both indoor and outdoor air quality parameters. Furthermore, considering that people pass most of their time in closed spaces and indoor environments, magnifies the significance of indoor air quality studying. So, in this research, the indoor air quality of residential houses in region 1 and 5 of Tehran has been studied with more emphasis on PM10. Some sampling stations (20 houses) have been selected on the basis of frequent surveys of the regions and the related maps to measure the pollutants. The result includes: Generally PM10 level in the stations which are near the street has been more than the stations which are located in the allies, in both regions.PM10 level in one-floor buildings has been more than the others.PM10 level in region 5 stations has been more than region1. The particulate matters distribution in 1, 2.5 and 10 micron categories are as following: There is a meaningful relationship between PM10, PM 2.5 and PM1 levels, when PM10 level is high, PM2.5 and PM1 levels are high too. According to the samples analysis PM10 concentration has been more than PM2.5 and it has been more than PM1 in turn. Steps to reduce exposure to particle matter include: sources controlling, proper ventilation, cleaning house, using appropriate equipment, solving planning, building and maintaining problems.
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