SOURCE APPORTIONMENT OF ATMOSPHERIC POLYCYCLIC AROMATIC-HYDROCARBONS COLLECTED FROM AN URBAN LOCATION IN BIRMINGHAM, UK

Intensive seasonal sampling campaigns were undertaken at an urban loca tion in Birmingham, U.K., in which high-volume samplers were used to c ollect particulate- and vapor-phase polycyclic aromatic hydrocarbons ( PAHs) by means of filter papers and polyurethane foam plugs. Eighteen PAH species were determined by reversed-phase HPLC. Additionally, the suspended particle loading of the air was measured gravimetrically. Di chotomous stacked filter units (DSFUs) were run simultaneously with th e high-volumes enabling the collection of particulate matter represent ative of fine (<2.1 mu m) and coarse sized (2.1-10 mu m) fractions. Fi lters from the DSFUs were analyzed for 19 metal species [by proton ind uced X-ray emission (PIXE)], ammonium, elemental carbon, and various a nions. Metal and PAH concentrations were observed to be broadly in lin e with concentrations measured at other urban areas throughout the U.K . Chemical source apportionment studies took the form of principal com ponent analysis (PCA) followed by multi-linear regression analysis (ML RA). This multivariate technique enabled major air pollution source ca tegories to be identified along with the quantitative contributions of pollutant species to each source group. The results demonstrate that a combination of measurements of PAH and inorganic pollutants is a far more powerful tracer of emission sources than PAH data alone. PAH wer e found to be associated predominantly with emissions from road traffi c, although other sources such as fuel oil, coal combustion, and incin eration also contribute. Road traffic accounts for 88% of ambient benz o[a]pyrene at our site.