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