The relative significance of vehicular emissions and other emissions of volatile organic compounds in the urban area of Leeds, UK

A volatile organic compounds (VOC) emission inventory for an urban area, Leeds in the UK, has been conducted using a wide variety of statistical information on population distribution, industrial employment, land use and traffic flow for the study area, and emission factors from technical literature. The inventory also includes the estimation of speciated VOC emissions using fingerprints for different types of source. The results for the city as a whole indicate that the greatest contributors are motor vehicles, followed by industrial and domestic use of solvents. Motor vehicles contribute 48% of the total emissions of VOCs in the study area, compared to 32% for the national figure for the motor vehicle contribution in the UK. For those emission sources which it was possible to speciate, road transport contributed a large proportion, 58%, which was further increased to 64% if photochemical oxidant creation potential (POCP) weighting was undertaken to assess the significance for ozone generation. The result of spatial disaggregation indicates substantial differences in the relative significance of vehicular emissions from one place to another. In the city centre, the contributions of motor vehicles are lower than outside the city centre due to the large emissions from a number of point sources in the inner area.