Organization of long range transport of air pollution monitoring in Europe

In the 1950s a network of stations for observation of the chemical composition of air and precipitation was established in Europe. Analyzing these data, Oden (1968) was able to show that a central area in Europe with highly acid precipitation was expanding from year to year. This was further substantiated by Granat (1972), and the explanation is the increasing use of fossil fuels in Europe. In 1969, the problem was examined by OECD, and on the initiative of the Scandinavian countries, a joint research program to study the long range transport of air pollutants was started in 1972. The program will be completed with a final report in 1976. In this program, atmospheric dispersion models are used to describe emission, dispersion and deposition of SO₂ and sulphate with particular emphasis on the acidification of the precipitation. An emission field has been constructed for Europe, and data from the European weather forecasting system are used for the dispersion calculations. Calculated concentrations and deposition are compared with data from about 70 ground stations and measurements from aircraft. Results show that the main cause for acidification of precipitation is the increasing use of fossil fuels. Large amounts of H₂SO₄ can be transported over distances up to a few thousand kilometers. In southern Scandinavia where the soil is highly acid (podsol), this has caused severe damage to life in rivers and lakes, and it is feared that in the future, there will be serious damage to forestry. In the Alps, where the soil has a high carbonate content, such effects are not expected. The long range transport of air pollutants has also been shown to increase the corrosion of materials. Work is now in progress to establish a more permanent system for the monitoring of air pollutants in Europe. The first plans for such a system were presented at the meeting in Oslo in December 1974, where countries from both Eastern and Western Europe participated. The work is supported by the Economic Commission for Europe, UN, in cooperation with other international organizations such as the World Meteorological Organization and the GEMS program of the United Nations Environment Programme. In this connection, studies have also been taken up in several countries concerning the effects of the long range transport of air pollutants. In the future monitoring system, a coordination of these efforts is envisaged.