Assessment of noise pollution indices in Birjand old districts in 2010

Noise pollution is recognized as a major problem in urban areas. Therefore، the current study was aimed to determine noise pollution indices in Birjand old districts. In this cross-sectional and analytical-descriptive study، noise measurement was performed by means of «CEL» sound level meter (model 450. 490). Equivalent noise level «Leq 10 min» was measured within four daily periods and within two periods at night، according to the procedures recommended by BS 7445-1-2003، as well as BS 7445-3-1991 standard، at each station. The obtained data was analysed using SPSS software (v; 16) by means of statistical tests Pearson and T-test The findings of the study showed that day-night mean sound level (Ldn) was significantly higher than the standard level in all stations (P>0. 05). The highest day–night mean sound level and maximum noise level belonged to Motahhary street (72. 2 dB) and Taleghani street (85. 9 dB). There were signifigant differences between day-night mean sound level and maximum allowable threshold in working day (P<0. 005) and holiday (P<0. 005). Since the level of noise pollution is critical especially along Taleghani Street which passes right through the city and along Emam Reza Hospital، as a sensitive area، it is necessary to design and apply suitable measurements، as well as to consider the level of their effectiveness in order to decrease noise pollution.