Evaluation of noise pollution in Sari (2007-2008)

Background and Noise is one of the most harmful factors in the environment. It is also one of the harsh phenomenons in this century that people are exposed to. Exposure to noise higher than threshold limit value could cause some physical and mental disorders. High traffic flow due to recent increase in number of vehicles causes higher noise pollution. There are few studies regarding the evaluation of noise pollution in the environment in some Iranian cities. Thus, it is necessary to measure sound pressure level and other related parameters for noise pollution control. Identification of the effective factors on noise pollution is the best approach for promotion of individual, as well as, public health and safety. The aim of this study is to evaluate the noise level in the city of Sari. There exist various methods for calculating the equivalent noise level regarding to noise measurement period. The most ordinary method is DL (day average sound level), that takes 15 hours of sampling (7 am- 10 pm), based on regulations that was approved by the National Environmental Protection Association in year 2003. This method was used for evaluation of noise level in this study. In the first stage, sampling locations were selected, followed by measuring sound levels at the height of one’s hearing zone (1.6 m above the ground surface). A calibrated sound level meter (Model Cell-490, Casella CEL, England) was used for all measurements. The SPSS software V.15 was used to perform T-test analysis. The results showed that the mean (SD) DL was 75.52± (4.41) dB. The minimum and maximum sound pressure levels during the sampling period were 47 dB and 121.5 dB respectively. Due to the measurement of various circumstances, some times, and also, sampling locations, measure sound pressure level was high. The mean sound level during the daytime period was higher than the national standard levels. Therefore, environmental noise control is the best approach for the prevention of noise related to adverse health effects.