The ambient noise monitoring was conducted at eight locations in Delhi during September-October, 2005. The objective of this study was to assess traffic noise exposure on residents living adjacent to major roads in Delhi.

The ambient noise standards prescribed in the Noise Pollution (Regulation & Control) Rules, 2000, specify the ambient noise standard for residential area for day time (06:00 A.M to 10:00 P.M) and night time (10:00 P.M to 06:00 A.M) as 55 dB(A) and 45 dB(A) respectively. The monitoring results indicated that the ambient noise levels for both day time as well as night time at all eight locations are much higher than the prescribed standards.

On the request of Delhi Development Authority (DDA), the Central Pollution Control Board conducted noise monitoring to assess noise levels at the proposed site for Commonwealth Games-2010 near Akshardham Temple during 20.10.2005 to 23.10.2005. The proposed site is situated on the east of River Yamuna between National Highway (NH) 24 and the Railway Track behind Akshardham Temple.

The noise parameters recorded were L_eq , L₁₀ , L₅₀ and L₉₀ for 16 hrs (day time – 6:00 a.m. to 10:00 p.m.) and for 8 hrs (night time – 10:00 p.m. to 6:00 a.m.) for all the six locations. Day time Sound Levels at locations 1 & 3 only conformed to the day time ambient noise standard of 55 dBA, whereas day time sound levels at other locations marginally exceeded the day time ambient noise standards. Night time sound levels at all the locations exceeded the night time ambient noise standard of 45 dBA. DDA was recommended to look into the possibility of providing Sound Barriers and taking other administrative steps to reduce noise pollution.

Ambient noise levels were monitored in Bhopal, Indore. Ajmer, Jodhpur, Udaipur, and Gwalior. The noise Levels were monitored at 18-20 Locations in each city covering Residential, Commercial, Industrial areas and Silence zones for Day and Night time. The high noise generating areas were identified based on the human exposure in each category.

Vehicular movements were the major source of noise in residential, commercial and silence zones. In industrial area, vehicles have also contributed some noise in addition to the industrial activities.

The bursting of firecrackers and Kalipuja celebrations are the major source of noise pollution during festival time. Ambient noise measurements were made at 27 locations across residential, commercial, industrial and silence zones in Kolkata city. Monitoring was conducted for two days representing the normal day prior to Kalipuja/Diwali festival and during the day of festival. Measurements were taken for 5-15 min. at same location 2-3 times during day time between 06:00 hrs to 22:00 hrs and once during night time between 00:00 hrs to 04:00 hrs. The salient observations are:

• Noise levels were found increased. Average increase in equivalent sound levels during Diwali was found 9dB_(A) in day time and 10dB_(A) in night time.

• In residential areas, average increase in ambient noise levels above the prescribed limit of 55 dB_(A) was 7 dB_(A) prior to puja while during puja the increase was 13 dB_(A).

• The residential areas namely Beliaghata, Kakurgachi, Cossipur, Jodhpur Park, Naktala, Behala, Lake Town and Deshpriya Park have recorded significant increase in noise levels on Puja day. However, the increase was insignificant in other residential areas viz. Park Circus, Mainktala and Kidderpur.

• The noise level a day prior to festival indicates that atleast 8 residential areas in the city (out of 18) were meeting the daytime ambient noise limits. However, during festival day, none of the residential areas in the city were found to be complying with daytime limits.

• There was no significant increase in daytime sound levels at sensitive areas such as SSKM and Command Hospitals. However, there was marginal increase in nighttime. Here the average nighttime sound levels prior to Diwali were above the permissible limit by 11 dB_(A) but on Diwali day the exceedance was 16 dB_(A).

Central Pollution Control Board in association with Tamil Nadu Pollution Control Board collected firecracker samples from 17 fireworks industries. Testing of these five cracker samples was undertaken at National Aerospace Laboratories, Bangalore for compliance of noise levels with the standards. Results reveal that only 37 samples out of the 76 samples complied with the noise limits.

Firecracker samples were also collected from 52 fireworks units located at Sivakasi by Tamil Nadu Pollution Control Board and got tested by Tamil Nadu Fireworks Association. Results indicated that 138 out of the 241 samples complied with the noise limits.

Fire cracker samples from Delhi market were also procured and noise level testings were carried out at National Physical Laboratory, New Delhi. Results indicated that 17 out of the 20 samples complied with the noise limits.

The 13^th Meeting of the National Committee on Noise Pollution Control was held on 4^th Oct, 2005 to discuss the following issues:

- Exemption from noise limits to the diesel generator sets used with submersible pumps for irrigation purpose.

- Noise Monitoring of diesel generator sets – representation from Delhi Pollution Control Committee

- Order of Hon’ble High Court of Delhi related to noise limits for diesel generator sets

- Order of Hon’ble Supreme Court on Noise Pollution

- Proposed Amendments on Noise Regulations

- Airport Noise Monitoring

The National Committee on Noise Pollution Control has been in the process for formulating suitable legislation in the country on aircraft/airport noise. As a first step, a ‘Draft Airport Noise Monitoring Procedure’ has been prepared, considering the prevalent noise monitoring procedure practised internationally and also the results of the detailed noise monitoring conducted in and around IGI International Airport. The document specifies the suitable requirements and procedures for airport authorities to undertake ambient noise monitoring around airports.

The Ministry of Environment & Forests, Govt. of India notified revised noise limits for diesel generator sets (upto 1000 kVA) vide GSR 371 (E), dated May 17, 2002 (and its amendments). The noise limits became effective from 1.1.2005. Based on the inspections at diesel genset manufacturing units in January – February, 2005, directions to seven genset manufacturers have been issued to install acoustic enclosure on all open gensets (upto 1000 kVA) manufactured and sold after 1.1.2005 at the customers site, or replace the gensets with compliant gensets within six months at their own cost. Based on the replies submitted by the genset manufacturers closure directions were issued to two genset manufacturers under Section 5 of The Environment (Protection) Act, 1986.

7^th Meeting of the Standing Committee on Emissions from RIC Engines for Off-Road Applications was held on 20^th June 2005 to discuss the preparedness of compliance with emission limits applicable from 1.7.2005, for diesel engine manufacturers (upto 19 kW) for genset application and other issues. Meeting on Emission from Diesel Engines (>800 kW) for Genset/Power Plant Applications was held on 3.6.2005 to assess the preparedness of the industry for compliance with next stage emission limits effective from 1.7.2005.