The World Heritage church of Asinou, in Cyprus, is filled with frescoes dating from the 12th century AD. During April 1997 - January 1998, an air quality monitoring program measured indoor and outdoor particulate matter samples each season. Particle deposition samples also were collected. Average coarse particle concentrations outside the church were 28.1 µg m-3 while outdoor fine particle concentrations averaged 16.4 µg m-3. Indoor average concentrations were 17.3 µg m-3 and 16.9 µg m-3 for coarse and fine particles, respectively. Particle deposition onto interior vertical surfaces over a nine-month period caused color changes that would be perceptible by a human observer (maximum color change ΔE=1.87). At these rates, the optical qualities of the frescoes will be clearly degraded over a period of five years. The installation of a mechanical air filtration system could reduce particle concentrations inside the church to less than 3% of uncontrolled levels.
Lynn Garry Salmon <>{