Chemical changes in test paintings measure the environmental impact on the museum collection

A novel method for monitoring of the museum environment using tempera based mock paintings is presented. Twelve different test strips were exposed to light ageing, thermal ageing and to air pollutants under laboratory conditions. A good correlation was observed between exposure time in the light and relative response in the various dosimetric paint strips. The methodology was applied to measure the environmental impact on paintings in selected field sites (4 museums and a chapel). Significant differences in the environmental conditions of these field sites were detected by the dosimetric strips. Data from lead white and sienna test strips are presented.The induced chemical changes under field conditions exceed what is expected from light ageing alone. Sienna appears to be especially sensitive for air pollutants like nitrous and sulphur oxides. Dosimetry using tempera based mock painting strips has been found to be successful. The relative sensitivity of the various test systems can be used to differentiate among contributions of specific environmental effects on the art work.