§ Lord Rotherwickasked Her Majesty's Government:
What figures are available for the amount of 3-nitrobenzanthrone emitted in diesel bus exhausts when such vehicles are under load; and [HL2650]
Whether they have undertaken research into the adverse effects of 3-nitrobenzanthrone emitted by buses under load; and [HL2651]
What information they have made available to the public on how to protect themselves against carcinogenic effects of 3-nitrobenzanthrone from diesel bus exhausts. [HL2652]
§ Lord Davies of OldhamThe National Atmospheric Emissions Inventory includes estimates for 16 polycyclic aromatic compounds (PAHs), but 3-nitrobenzanthrone is not included and there is no data as to its emissions from buses. The Department of Health reviewed work carried out in Japan several years ago on 3-nitrobenzanthrone and indicated that no conclusions could be drawn from the data on its potency as a mutagen or a carcinogen.
Nevertheless, PAH emissions remain a concern and the UK Government and the devolved administrations for Scotland and Wales introduced a new objective for PAHs into the Air Quality Strategy in 2003, based on a recommendation by the Expert Panel on Air Quality Standards. This recommendation is intended to reduce any risk to the population from exposure to PAHs to a level that the panel believes would be so small as to be undetectable. Evidence on human carcinogenicity of these compounds is based on studies of the effects of exposure to mixtures of PAH compounds. Setting health-based standards for individual PAH compounds is not currrently feasible.
Information on current trends in PAH emissions is available to the public at www.naei.org.uk. National emissions from all sources have decreased from 8,231 tonnes in 1990 to 1,944 tonnes in 2002 due to controls on emissions from industry, less use of coal for domestic heating and introduction of cleaner road fuels and tighter particulate standards for diesel cars and heavy vehicles. Total road transport emissions have decreased from 1,664 tonnes in 1990 (28 per cent of total emissions) to 1,050 tonnes in 2002 (54 per cent of total emissions).