Materials corrosion and air pollution. Long-term studies at the Lahemaa monitoring station, Estonia

Abstract

The Estonian Lahemaa monitoring station has participated in the International Co-operative Programme (ICP) on Effects on Materials, including Historic and Cultural Monuments (ICP Materials) since 1987. ICP Materials is an ongoing research programme in the framework of which air pollution and the effect of climate on the corrosion of various natural and synthetic materials, including on historical and cultural monuments, is studied. So far these studies have revealed that even though air pollution has continuously declined in Estonia, no significant reduction in corrosion on the displayed sample plates at the Lahemaa test site could be noticed. Just the opposite - in 2001-2002 the corrosion loss of zinc was greater compared with 1997-1998. It may have been caused by the fact that the reduction in air pollution has significantly affected the acidity of the precipitation and the decreased pH of the precipitation has in turn affected the corrosion of materials exposed at the Lahemaa monitoring station.