With Transport Minister K.N.Nehru recently announcing that a deadline would soon be set for all autorickshaws and taxis in the city to switchover to LPG (liquefied petroleum gas), the issue of ambient air quality and the strategy of adopting alternative fuels to make Chennai ‘greener' has come into focus again.

Of 62,000 autorickshaws that ply on the city's roads, 24,100 run on LPG. But, due to limited supply of the fuel, many of the autorickshaws fitted with an LPG-kit continue to run on petrol.

J. Seshasayanam, general secretary of Madras Metro Auto Drivers' Association, says, “There are only 22 operational Auto LPG dispensing outlets in the city. The filling capacity of each outlet is about 10,000 litres a day. However, demand is more than six lakh litres. More autorickshaws must not be forced to convert without addressing the issue of supply.”

He adds that any programme that attempts to make the city greener must start with the city's government-operated bus fleet.

According to the Comprehensive Traffic and Transportation Study for the Chennai Metropolitan Area (CMA), the levels of suspended particulate matter in the city ranges from 274 to 1,470 mg/m3, which is much higher than the World Health Organisation prescribed limit of 200 mg/m3.

The study also points out that emission from nearly 50 per cent of the vehicles in the city exceeds permitted levels. Approximately 70 per cent of the city's pollution load is vehicular.

“Air quality in the city has markedly deteriorated in the past decade,” says R.Sridharan of the Asthma Allergy Resource Centre.

“More numbers of younger children are showing asthmatic symptoms than ever before. It has also become difficult to treat asthma patients because they go out of the clinic and continue to breathe poor quality air,” he adds.

New Delhi was one of the first cities in the country to wake up to the problem of air pollution. In 1998, Delhi was one of the world's 10 most polluted cities.

Following a Supreme Court directive, nearly 80,000 commercial transport vehicles, including 9,000 buses, were converted to run on Compressed Natural Gas (CNG).

Anumita Roychowdhury, researcher at the Delhi-based Centre for Science and Environment (CES), says compared to 1996 levels, particulate pollution in Delhi dropped by 26 times by 2004.

“Scientific studies have shown that a gaseous fuel strategy, whether LPG or CNG, can substantially reduce emission levels,” she adds.

However, according to a study done at IIT-Delhi, even if only five per cent of regular bus users shifted to private modes, total carbon monoxide and hydro-carbon pollution would increase by 10 to 20 per cent.

“It is very important that fuel policies must be accompanied by other measures that ensure that use of public transport does not decrease,” says Dinesh Mohan, transportation professor at IIT-Delhi. The emission gains made in Delhi due to CNG conversion have almost been offset by the rise in the number of private vehicles, which have tripled in the last 15 years.

Polluted air is a symptom, a symptom of the absence of a coherent, integrated policy for transport, says Shreya Gadepalli, director, Institute of Transportation Policy (Ahmedabad).

“Clean fuels can be a part of the solution only if there are enough buses on the road to prevent more people from opting for personal transport.”

According to her, the government must rigorously impose emission norms instead of mandating the fuel type. “The issue is how we live and commute in our expanding cities. Fuel technology can lead to only a marginal improvement.”

Keywords: LPGautorickshaws