Assessment of noise pollution in region 16 of Tehran

Noise pollution is one of the most important and growing pollutions in large cities. Measuring sound pollution is an essential step to control and manage its effects. Therefore in this research, zoning and modeling of noise pollution was carried out in one of the densely populated areas of Tehran, region 16. In this study, at first eight stations were selected to study area.

At the next stage, 46 stations were selected in the studied area and the equivalent level of sound was measured for each station in three periods: in the morning, at noon and at night; and results were used to determine the level of sound pollution. In addition, one of pathways of transit network of area 16, i.e. Shahid Rajaei Highway was selected and noise intensity was measured at different intervals for zoning and modeling of noise pollution of that highway. Then, a model was proposed to predict the level of noise intensity at different distances from the highway. To verify the accuracy of the proposed model, another highway was investigated and a comparison test was performed between measured and predicted values.
Results and discussionL: The percentage error between predicted and measured values is very negligible and thus the proposed model can be used to evaluate the pollution of other highways. The results obtained from the main stage of this study revealed that the maximum average equivalent level of sound in highway is 83.5714 Db and highway side until 30 m is not suitable for residential use. The minimum average sound level allowed for residential areas is 58 db.

Other results of this study indicate that in all sound measurement stations in transit network, the mean measured equivalent level of sound is more than accepted standard in Iran. Due to high noise pollution in the area under study, the proposed solutions to control noise pollution are to use sound walls on highways and to create
more green spaces in areas prone to pollution.