The US Environmental Protection Agency has announced that President Bush's 2005 budget will include new funding worth $60 million to expand the Clean School Bus USA programme - a national partnership that aims to reduce the emission of air pollutants from school buses.

EPA administrator, Mike Leavitt, explaining the increase in funding from $5 million to $65 million, highlighted the 'President's commitment to protecting children's health and cleaning America's air'.

He added: 'It's a big increase because, as we see here, this programme works. As a result of this new funding, EPA can expand this programme from just 17 districts in 2004 to nearly 220 school districts all across the country.'

The additional funding will provide grants to governmental entities to replace pre-1991 school buses with new clean school buses offering state-of-the-art emission controls. Post-1990 buses will also be fitted with similar advanced emission controls.

The initiative was launched in April, 2003, with the goal of upgrading the nation's entire school bus fleet to low emission buses by 2010.

Diesel-oxidation catalysts are used to break down pollutants in the exhaust stream and transform them into less harmful components.

The EPA explained that catalysts can reduce particulate matter by at least 20 per cent, carbon monoxide by 40 per cent and hydrocarbons by 50 per cent.