ASSESSMENT OF AMBIENT NOISE LEVELS IN THE METROPOLITAN CITIES OF INDIA

Abstract

Noise has been identified as a pollutant under the Air (Prevention and Control of Pollution) Act, 1981, as amended by amendment act, 1987. The ambient noise standard has been laid down and notified under environmental protection Act (G.S.R. 1063 (E) dt. 26th Dec. 1989). Ambient noise is a composite of sounds from many sources. The ambient noise level is increasing day by day in urban estates due to fast growth of urbanisation and rapid change in life style of people. Acoustic noise beyond a certain limit is harmful. Noise is usually unwanted sound pollutant which produces undesirable physiological and psychological effects in an individual, by interfering with one’s social activities like work, rest, recreation, sleep etc. The fact that a regulation to abate noise is in force should remove all doubts about the damaging aspect of noise pollution. The metropolitan cities are being more polluted and the main thrust is towards the estimation of level of noise pollution in these cities. Measurement of noise levels were carried out in 7 metropolitan cities in India, viz. Bangalore, Chennai, Delhi, Hyderabad, Kolkata, Lucknow and Mumbai to assess ambient noise level during Diwali week. Measurement of noise levels were carried out in 4 zones of the metropolitan cities, viz. Commercial, Industrial, Residential and Silence zones. Based on the data of the measured equivalent noise levels in the residential, commercial, industrial, and silence zones of the 7 cities, it can be stated that during day time noise levels from 40 to 60 dB(A) prevail in residential areas away from traffic roads, noise levels from 60 – 80 dB(A) prevail in residential areas close to traffic roads and in commercial areas, noise level from 70 – 90 dB(A) exits at the traffic junctions and in industrial areas, and noise level from 80 - 105 dB(A) exists in areas with heavy traffic (Singal,2000, 2005). Even the silent zones are quite noisy as has been shown by data collected by CPCB. Further, merely 30% of the residential colonies in metropolitan cities have noise level within prescribed limits, the quiet period is only during the early morning hours from 0200 – 0500 hours when noise level falls within 40 – 45 dB(A), and the ambient noise levels during festivities e.g. Diwali festival becomes quite high i.e., from 85 – 120 dB(A). All noise level measurements were A-weighted.