§ Mr. Redwood
To ask the Secretary of State for Transport what pollutants, broken down by volume, are emitted by(a) an average 2003 saloon car with a petrol engine travelling with average fuel consumption, (b) a 10-year-old double-decker service bus, (c) a diesel multiple unit train and (d) bendy-buses. 
§ Mr. Jamieson
The emissions of some of the key pollutants (carbon dioxide, oxides of nitrogen and particulate matter) from the vehicles in question are shown in tabular form below. The data is from the 2001 National Atmospheric Emissions Inventory.308W
Grammes per vehicle km CO2 NOx PM10 2003 urban car (petrol) 155 0.14 0.001 1993 urban bus 1003 10.93 0.528 Average DMU train 1712 22.06 0.122 Bendy bus n/a n/a n/a
The car emissions are average figures for Euro III petrol vehicles operating at an urban speed. The bus emissions are average figures for Euro I vehicles also at an urban speed. It should be noted, however, that in practice many 10-year-old buses have been retrofitted with newer engines meeting tighter (ie Euro II or Euro III) emissions limits, or with pollution reducing equipment such as particulate traps. In these cases, emissions of NOx and PM10 would be much lower. Specific data for a bendy-bus is not currently available: much would depend on the age of the bus and the emissions standards it was required to meet at the time of purchase. The train emissions are average figures for diesel multiple unit trains used on regional networks. The majority of commuting by train is in London and the South East, where most of the trains are electric and so have zero local emissions. A full environmental comparison would need to incorporate occupancy figures but comparative data per passenger km is not available in the form requested.