Plans to tackle pollution problems caused by buses and other traffic in Oxford city centre are being drawn up by transport officials.

The level of nitrogen dioxide in Queen Street is almost twice the Govern- ment's recommended limit, and is also too high in other parts of the city centre to meet the 2005 objectives in the National Air Quality Management Strategy.

Nitrogen dioxide, contained in exhaust fumes, is less harmful than carbon monoxide, but can damage health if inhaled in sufficient quantities.

In Oxford, George Street, High Street and Park End Street also exceed the nitrogen dioxide target of 40 micrograms per cubic metre of air.

At tomorrow's meeting (January 27) of the county council's executive, David McKibbin, head of transport, will outline a series of measures to reduce air pollution.

These include asking bus companies to switch their engines off while waiting at stops in the city centre, and to add more low-emission vehicles to their fleets.

There are also plans to ban traffic other than buses from High Street, Magdalen Street, George Street, Castle Street and New Road, and to impose vehicle emission standards on all bus priority routes.

David Robertson, the executive member for transport, said a planned 20mph zone in the city centre would help to reduce bus emissions.

He added: "The long-term aim as part of the Westgate Centre redevelopment is to have a bus interchange, then we could get buses out of Queen Street, but at the moment that's simply an aim."