Because of their potential impacts on human health, welfare and our natural environments, ambient concentrations of a wide range of air pollutants - including ozone, nitrogen oxides, sulphur dioxide, carbon monoxide, particles, hydrocarbons and metallic pollutants - are measured at over 600 urban, suburban, roadside, industrial and rural locations throughout the UK. Automatic and non-automatic measurement techniques are used.| uk-air.defra.gov.uk