Journal of Environmental Health Science & Engineering34"ROAD TRAFFIC NOISE IN DOWNTOWN AREA OF TEHRAN "267272N. MansouriM. PourmahabadianM. Ghasemkhani20151209Noise pollution is a major problem for the quality of life in urban areas. The present study was conducted to determine the noise levels of road traffic at central area of Tehran. It focused on one of the busy and crowded square along with its 7 connecting streets, which had a heavy traffic and located in the downtown of the city. Total of 115 measuring points were selected along the roads, pavements and in the shopping areas to adequately represent the different acoustically commercial situations. The measuring points were divided in to 4 site-groups namely; Street, Pavement, Shop and Barrier each with 60, 40, 10, and 5 measuring points respectively. The measurements were carried out during a full week days started on Saturday morning and end on Friday evening. The A-weighted continuous equivalent sound level values, LAeq; LA max; LA min ; and the statistical levels: L1, L10, L50, L90 and L99 as well as the octave band center frequencies sound pressure levels were manually measured at each point separately. The mean values of LAeq for Street, Pavement, Shop and Barrier site groups were 78.5, 73.3, 68.7 and 70.8 dBA respectively and the overall mean of LAeq was 74.7 dBA. The statistical test (phttps://ijehse.tums.ac.ir/index.php/jehse/article/view/99https://ijehse.tums.ac.ir/index.php/jehse/article/download/99/98