Analysis and interpretation of the continuous hourly monitoring data for 26 C-2-C-8 hydrocarbons at 12 United Kingdom sites during 1996

A fully automatic network with 11 urban background and one rural site has b een set up and operated successfully in the UK to measure, continuously, ho urly concentrations of 26 C-2-C-8 hydrocarbons; the measurements collected form one of the largest data sets of urban hydrocarbon air quality data ava ilable anywhere in Europe. The hourly data have been analysed on a site-by- site and hydrocarbon-by-hydrocarbon basis by constructing scatter plots aga inst benzene. From: these scatter plots a number of important sources of hy drocarbon emissions have clearly been identified including: motor vehicle e xhaust and evaporative emissions, natural gas leakage, petrol station forec ourt evaporative emissions and industrial sources. Overall, urban backgroun d hydrocarbon air quality-is heavily influenced by motor vehicles and the g eneral pattern of relative concentrations has been accurately defined for t he United Kingdom as ratios relative to benzene. Comparisons of these conce ntrations are made with data for other major cities and with European regio nal data. (C) 1999 Elsevier Science Ltd. All rights reserved.