Noise Pollution and Traffic Noise Index on Mashhad Main Streets during the Busiest Hours of Summer

Abstract

Introduction: Among the environmental pollutions, noise is very important for its physiological <br /> and psychological effects on human. Traffic noise is one of the most important pollutants and the <br /> hospitals are one of the critical places regarding this type of noise. For these reasons, in the <br /> summer of 1382, the traffic noise of Mashhad main streets around the hospitals was assessed <br /> during the busiest hours. <br /> Materials and Methods: The noise indexes such as L Aeq , L Afmax , L 10 , L 50 and L 90 were measured <br /> by a Sound-Level-Meter, model Investigator 2260. The traffic load was also determined. On the <br /> basis of these results, Noise Pollution Level (NPL) and Traffic Noise Index (TNI) were <br /> calculated. The assessment was done during three different periods of the days in twelve stations. <br /> Results: Based on the obtained results, the maximum L Aeq was recorded on Bahar Street during <br /> the morning hours and on Koohsangi Street during the noon and night periods. Throughout the <br /> three periods the maximum NPL and TNI were estimated on Bahar and Nakhrisi Streets, <br /> respectively. The correlation between all of the indexes was analyzed and a logarithmic <br /> correlation was observed between L Aeq and the traffic load. <br /> Discussion and Conclusion: On the basis of the noise standard in free field in Iran, noise <br /> pollution is a serious problem in Mashhad.