i STUDY FOR PARTICULATE SAMPLING, SIZING AND ANALYSIS FOR COMPOSITION by A M King 1 , A M Jones 1 , S R Dorling 2 , J R Merefield 3 , I M Stone 3 , K Hall 4 , G V Garner 4 , P A Hall 4 and B Stokes 5 1 IMC Technical Services Ltd, 2 University of East Anglia, 3 University of Exeter, 4 Hall Analytical Laboratories Ltd and 5 CRE Group Ltd SUMMARY The aim of the project was to identify the origin of air pollution particulate matter, by simultaneously examining the size distribution within, and composition of, PM 10 and PM 2.5 particulate matter from a number of rural, semi-rural and urban UK locations. Two previous studies (ETSU Report Nos N/01/0032/REP, N/01/0033/REP), demonstrated that ambient background levels of PM 10 particulate matter form the majority component of urban levels. Exceedences of the 50μg/m 3 United Kingdom National Air Quality Standard (AQS), across the UK, were shown to be linked predominantly to national and trans-boundary phenomena (King and Dorling, 1997, 1998). These studies had been restricted to the assessment of PM 10 particulate matter, and little chemical characterisation had been undertaken. The Airborne Particles Expert Group (APEG) have come to similar conclusions on the importance of transboundary particulate matter, and have proposed changes to the National Air Quality Strategy to accommodate these findings. DETR have highlighted the implications of moving to a standard based on a finer size dust fraction, and the on-going debate over the suitability of TEOM monitors for statutory sampling. The report is comprised of four parts. Firstly, it reviews the findings of three studies, previously carried out in three distinct areas of the UK: ‘North-East’, ‘South-East’ and ‘South Wales’. Concurrent archive PM 10 samples, collected in the seven months October 1996-April 1997, were available for comparative analyses. Secondly, new samples of PM 10 and PM 2.5 material, and information on meteorological conditions, were collected over the six-month period 24 March-29 September 1998, at two rural locations, in east and south-east England, chosen to target the influence of ‘Continental’ air-masses, in relation to ‘UK’ emissions and ‘Prevailing’ winds. Concurrent PM 10 samples were also selected from South Wales, Cornwall, and from three Automatic Urban Network (AUN) sites. Samples were collected using TEOM monitors. Thirdly, the wide range of predominantly rural samples was then analysed for chemical composition, using a range of alternative and independent organic and inorganic analytical techniques, against a backdrop of meteorological analyses. Finally, results of the separate analyses were compared and analysed.