This volume is the 3rd in a series of comprehensive publications devoted to the molecular spectra and environmentally important properties of polycyclic aromatic compounds which constitute one of the most interesting classes of environmental carcinogens. Since the first identification of dibenz(a, h)anthracene and later benzo(a)pyrene as chemical carcinogens in the 1930's, the number of publications devoted to this ubiquitously occurring group of compounds has increased constantly. Therefore, this reference source for the spectral, physicochemical and en vironmentaJ properties of polycyclic aromatic compounds should be a welcome addition to the previous volumes for scientists engaged in the investigation, characterisation and control of this hazardous class of pollutants. As was the case with the preceding volume, this publication is the fruit of a close collaboration within the General Directorate for SCience, Research and Development of the Commission of the European Communities between the Environment Institute of the Joint Research Centre Ispra, the Community Bureau of Reference and expert laboratories in the member states. F. Geiss Director of the Environment Institute JRC Ispra 1. Introduction Polycyclic Aromatic Compounds (PAC) are an important class of carcinogenic environmental pollutants, which occur in air, water, soils, sediments, in food and in the work area. Because many hundreds of closely related isomers are being formed and released in the environment from combustion processes of fossil fuels and other organic materials, their environmental and health con trol presents a difficult task."

Based on the Lectures given during the Eurocourse on 'Practical Applications of Quantitative Structure-Activity (QSAR) in Environmental Chemistry and Toxicology' held at the Joint Research Centre Ispra, Italy, June 11--15, 1990

In many scientific branches, and especially the environmental sciences, the need for data treatment and evaluation is increasing continuously. Therefore, the interest and application range of multivariate analysis have expanded accordingly with a view of structuring, interpreting, and evaluating complex data bases. In this context, the present volume attempts to review the state-of-the-art in multivariate analysis and give an overview of the various fields of application in ecology, environmental chemistry, toxicology, risk analysis, and structure-activity relationship (SAR) studies. The first chapters of the book are focusing on fundamental aspects of multivariate analysis. The second part contains a number of case studies, with the application of basic methods such as principal component analysis, correspondence factor analysis, discriminant analysis, and neural networks. This book reflects and combines the lectures organized in June 1991 in the frame of the Eurocourse programme at JRC Ispra under the sponsorship of the Institute for the Environment. It was the intention of the course and the resulting publication to promote and stimulate the application of multivariate analysis in environmental sciences and related areas. F. Geiss Director Environment Institute JRC Ispra vii LIST OF CONTRIBUTORS AND LECTURERS Auda Y.: Maison de 1'0rient Mediterraneen, CNRS, Universite Lyon 2, 7 rue Raulin, 69007 Lyon, France. Bacou A.M.: Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, BP 5051, 34033 Montpellier CEDEX, France. Banco G.: Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, BP 5051, 34033 Montpellier CEDEX, France. Barny M.H.: Commissariat a l'Energie Atomique, IPSN, BP 6,92265 Fontenay-aux Roses CEDEX, France."

This volume is the 3rd in a series of comprehensive publications devoted to the molecular spectra and environmentally important properties of polycyclic aromatic compounds which constitute one of the most interesting classes of environmental carcinogens. Since the first identification of dibenz(a,h)anthracene and later benzo(a)pyrene as chemical carcinogens in the 1930's, the number of publications devoted to this ubiquitously occurring group of compounds has increased constantly. Therefore, this reference source for the spectral, physicochemical and en vironmentaJ properties of polycyclic aromatic compounds should be a welcome addition to the previous volumes for scientists engaged in the investigation, characterisation and control of this hazardous class of pollutants. As was the case with the preceding volume, this publication is the fruit of a close collaboration within the General Directorate for SCience, Research and Development of the Commission of the European Communities between the Environment Institute of the Joint Research Centre Ispra, the Community Bureau of Reference and expert laboratories in the member states. F. Geiss Director of the Environment Institute JRC Ispra 1. Introduction Polycyclic Aromatic Compounds (PAC) are an important class of carcinogenic environmental pollutants, which occur in air, water, soils, sediments, in food and in the work area. Because many hundreds of closely related isomers are being formed and released in the environment from combustion processes of fossil fuels and other organic materials, their environmental and health con trol presents a difficult task.

Polycyclic Aromatic Compounds (PAC) are a broad class of compounds whose wide distribution in the environment results from incomplete combustion processes of fossil fuels in power generator, industrial plant and domestic heating, from car exhaust gas and from tobacco smoke. Many PACs are biologically active and in particular many of the PACs with three or more fused rings are carcinogenic. Currently there is concern of the occurrence of these pollutants at ppb (ug.kg-1) le vel. However the predicted 2 to 3% annual increase in the rate of their release into 1 the environment could lead to ppm (ug.g-) levels in the next century. The move to wards stricter control of these pollutants brings with it the need for accurate monito ring of their environmental occurrence. Reliable identification and quantification of these compounds in complex environ mental samples depends greatly on the availability of reference values for their phy sicochemical and biochemical properties. This second volume results from a close collaboration within the General Directorate for Science, Research and Development of the Commission of the European Communities between the Joint Research Centre, Ispra Establishment, the Community Bureau of Reference and expert laboratories of the Member States."