Investigating Suspended Particles Resulted from Tehran's Highways Traffic

Measuring and monitoring the air is inevitable for investigating the air of surroundingenvironment and learning about the rate and density of the harmful effects of pollutionson the environment and humans` health. Air monitoring is an essential managingtool to monitor the air and reduce its pollution. The correct pollution management ispossible when reliable database of air qualitative status is available. To investigatethe role of different factors such as urban traffic on accumulation of air suspendedparticles, the particles` density at Navab Highway and Azadi St. were measuredin different crossroads and different circumstances. Two stations were selected ateach highway and suspended particles with PM1, PM2.5 and PM10 sizes as themajor pollutions were measured in summer, fall, winter and spring of 2009-2010at 1.8m and 5m from earth surface breathing heights. At the same time the sameparameters were measured to study the changes in suspended particles densitydue to wind speed and number of passing automobiles. The results showed thatthe more the automobiles pass the highway the more the density of suspendedparticles especially PM10 will be. The increase of wind speed will also result inthe increase of all three sizes of particles in mentioned highways. Meanwhile, thetotal average of suspended particles` density of PM1, PM2.5 and PM10 at NavabHighway has been upper than Azadi St. due to its south to north structure whichavoids cleaning effect of dominant western winds of Tehran city.