Providing a wealth of reference material for research scientists and policy makers, these proceedings address the extremely complex problem of acidification – a phenomenon which is causing serious deterioration of natural environments in Europe and North America. Papers review the effects of acidification on the aquatic environment, flora, fauna and vegetation, and materials, and also review cultural properties, the ecology as a whole and the economic impact of acidification. The papers on forest-dieback cover potential stress factors and the effects on materials and cultural properties. Scientific research results are presented which deal with models as tools for abatement strategies, and underline the application of models in policy-making. The review papers of scientific research on acidification are followed by the official report of the conference, and presentations by representatives of the EEC member countries giving an overview of national research programmes and policies regarding acidification.