Trehan and Aggarwal are among 1.25 lakh doctors who have signed on for a campaign to get diesel engines banned, which they consider mainly responsible for the deplorable state of the breathing apparatus of people in Delhi.

Leading the doctors is V Ramalingaswami, who estimates that one Indian dies prematurely every hour as the result of inhaling respirable suspended particulate matter (RSPM) originating mostly in diesel exhaust.

``As a first step we urge the government to stop the dieselisation of the private vehicle fleet. Commercial profit and public good have to be mutually compatible andreinforcing,'' says Ramalingaswami.

The doctors and leading environmental non-government organisations (NGOs) which support them are up against car manufacturers out to capitalise on government cross-subsidies on diesel fuel.

Ironically, one of the reasons for the liberalisation of the automobile industry in India was to facilitate introduction of cleaner technology to replace a fleet of cars designed in the fifties and sixties.

But seeing the huge popularity of diesel engines, and lax emission norms, manufacturers began offering diesel versions on nearly every petrol-engined model they were releasing in the market in spite of the known dangers. ``The smaller and deadlier of SPM, which are 10 microns or under, called PM10, cause severe lung damage and governments around the world are waking up to this fact,'' says Dr Aggarwal, who runs the Heart Care Foundation of India (HCFI), an NGO.

According to the World Health Organization (WHO), SPM is the most serious air pollutant on a worldwide basis andkills 460,000 people each year.Last October, environmental regulators in California voted to raise pollution standard for diesel engines to that applicable for petrol engines by 2004, virtually banning diesel vehicles from that year in the state.But as world opinion builds up against diesel engines, manufacturers are focussing on the rapidly expanding automobile market in India where emission norms are loosely enforced and diesel is subsidised to help farmers run tractors, pumps and agricultural equipment.

According to Sunita Narain of the Centre for Science and Environment (CSE), which is leading the campaign against diesel engines, automobile manufacturers are flooding the market with diesel-powered cars in spite of scientific evidence in their parent countries against the technology.Narain argues that since ambient SPM levels are already very high in Delhi and other Indian cities, selling diesel cars here is worse than selling it in places like California.

Manufacturers favour vehicles run on dieselbecause the fuel costs less than half the price of petrol in India thanks to cross-subsidies meant to protect the country's food security.

``Here the blame rests on the government's warped fuel pricing policies, which encourage auto majors to continue introducing diesel models into this country,'' Narain said.

The government is also responsible for the particularly poor quality of diesel that is available in the market and which would defy any attempt by manufacturers to improve emission, she said.

Government reluctance to crack down on diesel-powered car manufacturers comes at a time when supreme court has ordered buses plying in Delhi to begin switching over from diesel to compressed natural gas (CNG).

The Supreme Court has also ordered all new petrol and diesel passenger cars vehicles to conform to Euro II norms in Delhi by April 2000.

But that, say the doctors and environment groups, is not good enough because the extraordinarily high levels of SPM in the city air demands a complete ban ondiesel engines.

--Inter Press Service