Journal of Environmental Biology

Assessment and analysis of noise levels in and around Ib river

coalfield, Orissa, India

Author Details

Haraprasad Mohapatra

Department of Zoology, Kaptipada College, Mayurbhanj-757040, India

Shreerup Goswami

(Corresponding author)

Department of Geology, Ravenshaw University, Cuttack-753003, India?? ?????????

email: goswamishreerup@gmail.com

Publication Data

Paper received:

14 December 2010

Revised received:

02? July 2011

Accepted:

06? August 2011

Abstract

Heavy earth moving machineries, different capacities of dumpers and loaders, blasting and drilling make the mining environment noisy. A study was carried out to assess the noise level in different opencast projects in and around Belpahar and Brajarajnagar areas of Ib river coalfield. Noise assessment was carried out in various residential, commercial and industrial places. The noise levels, especially L_eq values of different wheel loaders, dumpers, shovel and crusher units were also assessed and were more than permissible limit (90dB) in some of their operating conditions. Sound ressure level measurements while drilling into coal and overburden at Lakhanpur opencast project yielded noise levels (L_eq) of 81.33 to 96.2 dB. Thus, these L_eq values of drilling machines in most of the operating conditions were above permissible limit. The average noise intensities (6 a.m.-10 p.m.: 51.6-60.875dB and 10 p.m.-6 a.m.: 42.6-49.8dB) and L_eq values (6 a.m.-10 p.m.: 50.9-67.0dB and 10 p.m.-6 a.m.: 40.8-53.3dB) during both day and night time of the residential areas around the Ib river coalfield were in close proximity or beyond the permissible limit. The L_eq values at some of the commercial and industrial places were beyond (6 a.m.-10 p.m.: 61.6-88.3 dB and 10 p.m.-6 a.m.: 55.4-64.8dB) permissible limit. However, in most of the cases, the L_max noise values were more (6 a.m.-10 p.m.: 68.5-91.4 dB and 10 p.m.-6 a.m.: 69.3-76.4dB) than the permissible limit. Analysis of variance was also computed for heavy earth moving machineries in different operating conditions and also for different residential, commercial and industrial places to infer the level of significance. The difference of noise intensity produced by different wheel loaders at Lakhanpur and Lilari opencast projects, drilling machines at Lakhanpur opencast project, 50 tons capacity dumpers at various conditions of Ib river coalfield within the same operating condition was significant at both 5% and 1% levels of significance. Similarly, the variance of estimated noise level in residential places during day time and commercial and industrial places during day and night time was significant at both 5% and 1% levels of significance. Moreover, a preliminary survey adopting questionnaire method amongst the mine workers and local inhabitants was also carried out to evaluate their perception about the mining related noise. ??????????

Key words

Coal mining, Noise pollution, Community response ??

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