Dosimetry of paintings: Chemical changes in test paintings as tools to assess the environmental stress in the museum environment

Painted works of art on display in museums are subject to many environmental factors. These include light intensity, temperature, relative humidity and air pollution. As these factors can have both synergistic and inhibitory effects, the overall effect of the environment is a non-linear function of each of these factors. Hence, unless the nature and extent of interaction of the factors are known in detail, separate measurement of each of these individual factors does not result in an accurate assessment of the effect of the environment on the works of art. We have developed a dosimeter based on traditional artists' materials to measure the overall effect of the museum environment on paintings. Changes in the chemical composition of these dosimeters are used as indicators of the environmental impact. This paper presents results of nine months' exposure of our dosimeters to museum environments in the Rijksmuseum (The Netherlands), the Tate Gallery (England), the Uffizi (Italy), the Alcazar in Segovia (Spain), and Sandham Memorial Chapel (England).