CHENNAI: : The air in Chennai will now be under the microscope more than ever before.

After drawing up a road map for implementing the National Auto Fuel Policy, the State Government has set up a committee under the Chief Secretary to supervise, monitor and coordinate implementation of a plan for improving the city's air quality.

The Tamil Nadu Pollution Control Board, along with the Central Pollution Control Board, the Indian Oil Corporation and the National Environment Engineering Research Institute, will soon embark on a project to apportion the source of air pollution in Chennai during 2005-06.

According to the Chennai Ambient Air Quality Monitoring Programme conducted by the TNPCB in 41 locations in May this year, the respirable suspended particulate matter (RSPM), total suspended particulate matter (SPM) and levels of sulphur-dioxide and oxides of nitrogen were within the National Ambient Air Quality (NAAQ) standards in most places except Thiruvotriyur, officials said.

Even the air in the highly industrialised Kathivakkam and Manali confined to the standards, officials claimed. This was in contrast to the situation in New Delhi, Kolkata and Mumbai, where the RSPM and SPM levels exceeded the standards even in residential areas.

While Kathivakkam recorded an annual average of 77 microgram per cubic metre of RSPM and 134 mg per cubic metre of SPM, the readings at Manali were 99 and 192. The NAAQ standards for industrial areas are 120 and 360. Thiruvotriyur, which fell under the `mixed category', showed readings of 86 and 136 as against the NAAQ standards of 60 and 140 in the category.

As vehicular exhaust was found the single biggest contributor to air pollution, the Government is considering issuing a directive to all autorickshaws and government vehicles to convert to liquefied petroleum gas and requesting the Environment Pollution (Prevention and Control) Authority, New Delhi, to expedite the supply of compressed natural gas and liquefied natural gas for diesel vehicles.

Industries have been asked to develop a green belt of 25 per cent of the project area for pollution abatement. No new polluting units will be permitted within the city. All industrial units have been directed to be fitted with computerised monitors to record stack-pipe emissions, the officials said.