DIRECT AND INDIRECT AIR-POLLUTION EFFECTS ON MATERIALS INCLUDING CULTURAL MONUMENTS

Damage causal to materials exposed in the atmosphere constitutes one o f the most important direct effects of acidifying air pollutants. Syst ematic field and laboratory investigations performed in the recent dec ade in many countries have contributed to a considerable increase in t he knowledge on the mechanisms of the effects of pollutants, on the qu antification of damage and on the assessment of the cost of damage. Be side the very important role of SO2 for several materials also studies of the direct or synergistic effect of NOx and O-3 have contributed t o the understanding of the complex pollution effects. Even if there am still considerable saps of knowledge it seems that NOx and O-3 may co ntribute in an important way to the deterioration of several materials also in indoor environments which are important for it electronic equ ipment, storage conditions and museums. Important knowledge has been g ained from the International Cooperation Project within UN ECE which i s an extensive field exposure an 39 test sites. Dose-response relation s have been obtained after 4-year exposure showing the effect of dry a nd wet deposition on corrosion of several material groups. Also the ef fect of micro- and mesoclimate on corrosion of building materials like plaster and bricks in different positions oa buildings and locations within an urban area has been subject to systematic studies. Results f rom the studies am used it for assessment of so called acceptable corr osion levels and for mapping areas where the levels Ire exceeded at di fferent pollution scenarios, as well as for calculation of economic da mage Based at model studies for some dry areas tentative calculations of damage ant have been performed for the European region. The indirec t effects consist of increased corrosion due to water and soil acidifi cation which am of importance in geologically sensitive areas. Structu res which am in contact with soil and water represent a very great cap ital investment and am of vital importance to the community.