Sound level in a ten year period in Shahrekord City

Noise is part of daily life in all human societies. It, like other pollutants, decreased the quality of life and is a hazard for public health. Therefore, the aim of this study was to find field data with respect to noise in the urban areas and to use data for applying measures to limit and control the exposure rate to environmental noise. In this study, sound level was measured across the city based on heavy, moderate, and light traffic jams; residential, educational, and remedial areas. Measurement was conducted in two times, 1992 using 8 stations and 2001 using 10 stations. To determine the noise level based on the public opinions, 20 persons were randomly selected in each overcrowding station and interviewed. The data was analyzed using Wilkoxon, chi-square and binomial analyses. The average of daily sound level in the first and the second period was 68.8±6.3 and 61.6±5.1 dB, respectively. The average of night sound level in the first and second period was 73.8±7.7 and 62.6±5.9 dB, respectively (p>0.05). The average of sound variations during day and at night was 24±5.2 and 24.5±5 dB in the first period and was 28.8±8.7 and 23.4±4.5 dB in the second period, respectively. Twelve percent of the citizens in the first and nineteen percent of them in the second period complained about noise pollution. As one of the most important environmental problems, noise was ranked fifth and third in 1992 and 2001, respectively. Our results showed that civilization patterns are improved slower than growth rate of noise-causing factors across the cities.