The report examines the extent of environmental damage in the Community and in certain other European countries that may be attributable to acid pollutant emissions within Member States. The study assesses the evidence for possible causal effects and considers the physical, chemical and biological processes which have been suggested as damage mechanisms. Concern in Europe has grown in the past few years as a result of observed damage to forests found principally in central and southern Germany, and also because of the loss of fish populations in the lakes of parts of south west Norway and Sweden. More recently, a few lakes, rivers and streams in Scotland, England and Wales, with geological and upper river catchments similar in character to those areas of Scandinavia referred to, have also reported absence or death of fish. Acid precipitation is considered a possible contributory cause. Loss of needles from pine trees has also been found in other areas of the Community. Less well appreciated is the existence of damage to building materials, caused by short range acid pollutant effects and the possibility under certain conditions that yields of some crops and vegetables are affected by the dry deposition of acid pollutants and their derivative products. Historically most attention has focused on S02, and its oxidised 'wet' form, sulphuric acid. Overall emissions of S02 in the Community have declined in the last ten years and this trend may well continue.

'Acid rain' is a broad term used to describe several ways that acids fall out of the atmosphere. A more precise term is acid deposition, which has two parts: wet and dry. Wet deposition refers to acidic rain, fog, and snow. As this acidic water flows over and through the ground, it affects a variety of plants and animals. The strength of the effects depends on many factors, including how acidic the water is, the chemistry and buffering capacity of the soils involved, and the types of fish, trees, and other living things that rely on the water. Dry deposition refers to acidic gases and particles. About half of the acidity in the atmosphere falls back to earth through dry deposition. The wind blows these acidic particles and gases onto buildings, cars, homes, and trees. Dry deposited gases and particles can also be washed from trees and other surfaces by rainstorms. When that happens, the runoff water adds those acids to the acid rain, making the combination more acidic than the falling rain alone. Prevailing winds blow the compounds that cause both wet and dry acid deposition across state and national borders, and sometimes over hundreds of miles. This new book combines an excellent background article with over 900 abstracts and book citations. Easy access is provided by title, author, and subject indexes.