COMPARATIVE RECEPTOR MODELING STUDY OF AIRBORNE PARTICULATE POLLUTANTS IN BIRMINGHAM (UNITED-KINGDOM), COIMBRA (PORTUGAL) AND LAHORE (PAKISTAN)

Samples of airborne particulate matter have been collected in three ci ties in different parts of the world. In Birmingham, U.K. and Coimbra, Portugal, samples were of PM10, whilst in Lahore, Pakistan, total sus pended particulates were collected. The samples have been analysed for a wide range of metallic constituents, black carbon and organic carbo n, and the soluble ions, SO42-, NO3-, Br-, Cl- and NH4+. A receptor mo delling study has been conducted for data from each city using Princip al Component Factor Analysis followed by multi-linear regression analy sis in order to provide quantitative insights into the sources of spec ific chemical components and total particulate matter (or PM10) in the three cities. This methodology, applied separately to coarse and fine fractions in the samples collected in Birmingham and Coimbra, reveals between four and six source categories according to location and size fraction, and whilst the sites in Birmingham and Coimbra in northern and southern Europe, respectively, show considerable similarities, the re are large contrasts with Lahore with its dryer climate and poorly c ontrolled pollution sources. A detailed intercomparison has been condu cted into the source attributions for lead and for PM10/TSP. In the ca se of lead, the source attributions in Birmingham are shown to corresp ond closely to the national atmospheric emissions inventory. Large dif ferences between the cities in source contributions are seen in the ca se of PM10/TSP, with soil dust estimated to contribute 62% of total su spended particulate matter in the atmosphere of Lahore, but contributi ng much less in Birmingham and Coimbra where road traffic emissions co mprise a substantial percentage of the total. (C) 1997 Elsevier Scienc e Ltd.