INDOOR AIR QUALITY MEASUREMENTS IN MUSEUM MICROENVIRONMENTS

摘要

Indoor air quality in historical buildings and museums is receiving growing concern nowadays among the scientific community. Natural decay of many exhibited artworks is accelerated by non-controlled environmental conditions or by exposure to gaseous pollutants, airborne particles or microbes, emitted indoors or penetrating from the outdoor environment. Therefore, monitoring and controlling the indoor microclimatic conditions (temperature and relative humidity) and the levels of indoor pollution is of critical importance for the applied conservation and preservation strategies of cultural heritage. In this study, one year indoor/outdoor measurements of gaseous pollutants (NO_2, SO_2, O_3, VOC's, CO_2, acetic and formic acids) and microbial load were conducted at the Historical museum of Crete, located in Heraklion (Greece) and at the Limassol Municipal Gallery (Limassol, Cyprus). Passive diffusive samplers and online monitors were used for gas collection in both museums. Airborne microorganisms were collected with microbial air samplers. Furthermore, indoor and outdoor temperature and relative humidity were monitored throughout the measurement period. Data were collected at several locations inside the museums according to the vicinity of the exhibits, to possible outdoor air entries to the indoor environment (main entrance, open widows, etc.) In order to estimate the effect of indoor pollutants on vulnerable materials exhibited in the museums (wood, paper, leather etc), early warning dosimeters were deployed at several indoor locations and also outdoors. These dosimeters are sensitive to SO_2, NO_2, O_3, temperature, relative humidity, and UV-radiation and can detect unfavourable conditions before any noticeable changes on museum artwork are observed.The results showed that the outdoor environment can significantly affect indoor air quality. In addition indoor activities and the presence of people can result in increased concentrations of indoor pollutants. The extent of the latter effect was not the same in all measurement locations, and depended on the combination of the presence of possible indoor pollution sources and the penetration of outdoor pollutants. The findings of this study can be used in the deployment of preventive actions regarding the protection of sensitive artworks from air pollution.