Mitteilungen des Österreichischen Staatsarchivs 39. (1986)
Archive Buildings and the Conservation of Archival Material. An Expert Meeting, held in Vienna, Austria October 30 - November 1, 1985 - THOMAS, David: Architectural Design and Technical Equipment for the Physical Protection and Conservation of Documents
240 Archive Buildings affected by acid damage caused by air pollution. Symptoms include degradation of leathers and yellowing and brittleness of paper. A comparative study of identical copies of 2 5 seventeenth and eighteenth century books in two English libraries, one in the normally clean atmosphere of rural Chatsworth and the other in the badly polluted city of Manchester revealed a higher level of paper acidity in the Manchester copies30). Archives located in desert areas or close to the coast may be affected by small particles of salt and silica which can affect photographs by attracting moisture and promoting localized chemical activity and encouraging micro-organisms31). The future trends of air pollution are difficult to guess. Pollution levels in the United Kingdom have been falling since the end of the nineteenth century, helped recently by clean air legislation and a switch to the use of cleaner, low sulphur oil from the North Sea. More recently, there have been some less positive developments; there has been a switch from the use of oil to coal and a change to the use of more highly polluting diesel engines by private motorists. There is also some evidence that the need to conserve energy has led building operators to reduce levels of ventilation; sometimes to levels below that suggested as the minimum requirement32). This practice would certainly lead to a higher build-up of pollutants within a building. For archives facing problems with air pollution, the alternatives are depres- singly few. One obvious choice is to locate or relocate outside urban areas; but this may be politically or financially impossible. The only other wholly satisfactory solution is to install full air-conditioning. The use of simple fans and filters is not satisfactory; a fully ducted system is necessary so that all the room air passes through the filters. The air-conditioning system should provide a slightly raised pressure inside the building to reduce infiltration. There should be two systems of filters: ones to remove particules and ones which are active against gases33). The use of an air-conditioning system without gas filters could accelerate the rate of decay of materials if it introduced polluted air from the atmosphere or if it added moisture34). The most suitable filters for use against gas are water spray which are effective against sulphur dioxide, nitrogen oxides, but not ozone; or activated carbon which is effective against ozone and sulphur dioxide, but does not always remove nitrogen dioxide 35). 30) Baer-Banks Indoor Air Pollution 14. 31) Kodak Preservation of Photographs (Rochester 1979) 25. 32) S. Hackney The Distribution of Gaseous Air Pollution within Museums in Studies in Conservation 29 (1984) 105-106; I. Turiel and others The effects of reduced ventilation on indoor air quality in an office building in Atmospheric Environment 17 (1983) 53. 33) Yocom Effects on Indoor Air Quality 119; Thomson The Museum Environment 128-130, 149-151. 34) Hackney The Distribution of Gaseous Air Pollution 114-115. 35) Thomson The Museum Environment 149-151.
