HC Deb 26 March 2002 vol 382 cc958-9W
Mr. Clifton-Brown

To ask the Secretary of State for Transport, Local Government and the Regions (1) what information he has collated on the effectiveness of particulate traps, as fitted to vehicle diesel engines, for the reduction of emissions of (a) PM2.5 particles and (b) oxides of nitrogen; [45898]

(2) if he will make a statement setting out the measures and policy objectives, including targets, the Government have to reduce emissions from road traffic of (a) benzene, (b) 1,3 butadiene, (c) particulates and finer particles (PM10 and PM2.5), (d) carbon monoxide, (e) sulphur dioxide and (f) oxides of nitrogen. [45946]

Mr. Jamieson

The effectiveness of diesel particulate filters has been the subject of a number of studies in recent years. All show that these filters can effectively remove more than 90 per cent. of particulate matter including all particulates that would contribute to the PM2.5 value.

Controls of oxides of nitrogen is not the objective of a particulate filter, but depending upon the specific system design, reductions can be achieved. Departmental research on heavy-duty engines has shown that systems comprising an oxidation catalyst and particulate filter can reduce NOx by approximately 10 per cent.

The Government's measures and policies for tackling air pollution from road transport, industry and other sources are set out in the Air Quality Strategy for England, Scotland, Wales and Northern Ireland, published in January 2000. It includes ambient air quality standards for benzene, 1,3 butadiene, particles (PM 10) carbon monoxide, sulphur dioxide, nitrogen dioxide, lead and low level ozone and objectives for their achievement between 2003 and 2008. Proposals were issued last year to strengthen the objectives for PM 10, benzene, carbon monoxide and introduce a new objective for polycyclic aromatic hydrocarbons. The current advice from the advisory Expert Panel on Air Quality Standards is that PM10 provides the most appropriate basis for an air quality standard rather than the finer fraction particles PM2.5.