Viable Airborne and Deposited Microorganisms inside the Historical Museum of Crete

摘要

Measurements of the ambient viable microbe concentrations and of the microbial deposits on surfaces were performed in the Historical Museum of Crete over a period of two years. The levels of the airborne microbes in the museum rooms showed considerable variability, which was mainly related to the indoor activity (such as the number of visitors); indoor environmental conditions, including the air exchange rate; and exhibits’ chemical compositions and storage conditions as well as the conservation treatments and cleaning techniques to which they had been subjected. An enrichment of acid-producing bacteria, heterotrophic bacteria, and autotrophic chemolithotrophic bacteria was encountered indoors, but a considerable decrease in the viable microbes, ranging from 5.5% to 76%, was detected after the deployment of photocatalytic ionizers at the different measurement sites inside the museum. These ionizers mainly improved the air quality by reducing acid-producing bacteria, which potentially contribute to deterioration in cultural heritage objects.