§ Mr. Horam
Research is already being carried out into the contribution made to photochemical oxidants by exhaust emissions from motor vehicles. Photochemical air pollution, including ground level ozone, occurs rarely in the United Kingdom but is one of the factors in mind in controlling vehicle emissions. All new petrol engined vehicles produced in the United Kingdom since 1973 have had to be constructed to meet emission standards drawn up under the auspices of the United Nations Economic Commission for Europe. These standards were tightened in 1977; and measures are in train to tighten them further.