Status of Ambient Noise Level in Chennai City and Strategy for Mitigation

Environmental noise is an important public health issue, featuring among the top environmental risks to health. Central Pollution Control Board in association with State Pollution Control Boards established a national ambient noise monitoring network covering metropolitan cities in the country. Under this monitoring programme, the ambient noise level of Chennai city is being monitored on real-time basis at ten stations since 2015. The noise level recorded in these ten stations during 2020 was analysed on a daily, monthly and annual basis. The daily data reveals that daytime Leq varies from 30.38-92.50 dB(A), L₁₀ varies from 63.61-87.34 dB(A), and L₉₀ varies from 44.38-64.82 dB(A). The nighttime Leq varies from 30.23-90.47 dB(A), L₁₀ varies from 57.90-88.16 dB(A) and L₉₀ varies from 40.82-65.62 dB(A). The monthly average data reveals that two stations exceeded standards in all the months. The annual average data reveals that seven stations exceeded standards. The main source of noise is the road, rail and air traffic, construction, commercial, industrial, social and entertainment activities. Ambient noise can be controlled by various mitigation strategies including traffic management, control of vehicle speed and maintenance of roads, mass awareness, removal of encroachments and providing noise barriers, like tree plantation, zoning of areas to maintain separation from excessive noise zone, ban of the bursting of firecrackers, ban of air horns, loudspeakers, limiting the use of construction equipment at night, engaging quieter vehicles for waste collection and other public services, limiting the use of loud machinery and equipment, subsidize acoustical retrofits (for example double pane windows, mechanical ventilation) for existing residential buildings near traffic noise sources, proper land use planning and comply the noise standards.