Intern. J. Environmental Studies, 1990, Vol. 36, pp. 273-277 © 1990 Gordon and Breach Science Publishers Inc. Reprints available directly from the Publisher Printed in the United Kingdom Photocopying permitted by license only THE IDENTIFICATION OF SOURCES OF POLYCYCLIC AROMATIC HYDROCARBONS (PAH) BY USING CONCENTRATION RATIOS OF TOTAL PAH AND LEAD HIAN KEE LEE,† GRAEME J. WRIGHT‡ and WILLIAM H. SWALLOW§ (Received in final form January 5, 1990) A technique for the identification of the source-origins of polycyclic aromatic hydrocarbons (PAH) present in the atmosphere is described. This technique uses the total concentrations of PAH (determined by capillary column gas chromatography) and Pb (quantified by atomic absorption spectrophotometry) which are subjected to statistical analysis. It is found that the method is sensitive and can be used to differentiate between sites burdened with different types (traffic, domestic or mixed) of atmospheric PAH pollution. KEY WORDS: Polycyclic aromatic hydrocarbons, lead, source-origins, multi-variate analysis. INTRODUCTION Polycyclic aromatic hydrocarbons (PAH) are proven carcinogens which are present ubiquitously in the environment. They have been the subject of intensive study during the past few decades, especially in the industrialized countries where the potential for the production and subsequent emission of these compounds into the environment as a result of industrial and other related activities is high. Other major emission sources include domestic space heating activities in temperate countries where coal and wood are still being used in fire places, and motor vehicles. Emission from motor vehicles, of course, now applies to the more built-up areas of even non-industrialized countries—these are the areas where large numbers of fossil fuel-driven vehicles are in use. The identification of the sources of emission of PAH should always be an important corollary of the analytical chemistry of these compounds. Too often, however, this crucial facet of source identification in PAH analytical studies is ignored or relegated to a side issue, mainly for reasons of difficulty in establishing suitable techniques to determine these sources or origins. This is unfortunate because knowledge of the nature of these sources provides the relevant authorities with the necessary information to evaluate the risks posed by these compounds. Having access to such information, these authorities are then able to develop control measures to eliminate or at least minimize indiscriminate PAH emissions into the environment. The toxic properties of PAH should provide the impetus to include such identification procedures within the wider framework of the analysis of these compounds. † Department of Chemistry, National University of Singapore, Kent Ridge, Republic of Singapore 0511 and to whom correspondence should be addressed. ‡ Department of Chemistry, University of Canterbury, Christchurch, New Zealand. § Wheat Research Institute, Ilam Research Centre, Christchurch, New Zealand. 273