Urban environmental noise monitoring Liaoning province during 2001-2007

ObjectiveTo uderstand the urban environmental noise pullution conditions for improving environmental quality.MethodsThe regular noise monitoring data for different urban funtional zones in 14 cities of Liaoning province were collected and analyzed.The equivalent continuous noise level(Leq)and national standard were adopted to evaluate the degree of noise pollution.ResultsIn the periods of seven years,the values of Ln(Leq)were 57 3-62.1dB(A)for the fourth type function zone of cities at night time with 100% of values over the national standard.There was a 40% increase of traffic with a 2.1 dB(A)decrease of environmental noise around two sides of main traffic roads in the seven years.The average Leq level for 14 citices in seven years was 55.3 dB(A)(54.2-56.1 dB)without obvious alteration.ConclusionEnvironmental noise of the fourth function zone decreased year by year but still exceeded limitation value of the state.The road traffic noise of cities in Liaoning was improved obviously.