Proposal for an integrated approach to microbial environmental monitoring in cultural heritage: experience at the Correggio exhibition in Parma

Abstract

Microbial environmental monitoring represents one of the most useful methods to assess potential risks related to the integrity of cultural heritage and people's health. The monitoring plan described in the present work is based on standardized techniques for measuring microbial air and surface contamination. Air contamination is assessed through both active and passive samplings, measuring the concentration of microbes in air (in colony forming units per cubic metre, CFU/m 3 ) and the rate at which microorganisms settle on surfaces (expressed by the Index of Microbial Air Contamination, IMA, CFU/dm 2 /h). For surface contamination, two parameters are measured using nitrocellulose membranes: the Microbial Buildup (MB, the total number of microorganisms accumulated on a surface in an unknown period of time prior to the sampling) and the Hourly Microbial Fallout (HMF, the number of microorganisms that settle on a specific surface during 1 h). The monitoring plan was implemented at the Pilotta Palace in Parma, Italy, during the Correggio exhibition in 2009. Samplings were taken before and during opening times. Some microbial contamination was already detected before the arrival of visitors: air contamination mean values of 99.1 CFU/m 3 and 5.2 CFU/dm 2 /h were recorded, while MB and HMF mean values for surfaces were 92 and 7 CFU/dm 2 , respectively. A significant increase was recorded in air contamination during opening times, with mean values of 323.7 CFU/ m 3 and 19.4 CFU/dm 2 /h; surface contamination values increased as well. This monitoring plan represents a contribution towards the definition of a much needed standardized methodology.

The assessment of fungal bioaerosols in the crypt of St. Peter in Perugia (Italy)

“…The passive method, applied through the technique of impactsedimentation on Petri dishes, allowed the achievement of information on the part of bioaerosols that can be deposited under gravity onto a surface. This provides indications of the levels of contamination in the environment and the depositing risk to artefacts maintained in the crypt (Pasquarella et al, 2011). The method of active sampling, which was carried out through the use of the Andersen instrument, allowed the measurement of the concentrations of particles in the air that can be deposited by sedimentation or other mechanisms, providing, in particular, quantitative data on the viable suspended microflora.…”

Fungal Community Analyses of a Pirogue from the Tang Dynasty in the National Maritime Museum of China

“…Indoor fungi not only exist in the form of spores in the air but also colonize various materials as mycelia. Museums are colonized by various microbes, and the detailed lists of these species vary according to the type and organization of the museum, the type of exhibit, the indoor microclimate, and the local environment [2,[28][29][30]. The most common colonizing fungal taxa are species of Penicillium, Cladosporium, Alternaria, Aspergillus, and Chaetomium.…”

The community distribution of bacteria and fungi on ancient wall paintings of the Mogao Grottoes

“…Many of the microorganisms identified in this study are biodeteriogens that cause spots-disease, such as Aspergillus and Pseudomonas , and produce organic acids in the environment 38 39 . The occurrence of fungi such as Alternaria and Aspergillus and bacteria such as Bacillus and Pseudomonas in the air at heritage sites has been reported repeatedly 19 40 . The present study also revealed that the microbial communities on the wall paintings did not differ from those in other caves in the Mogao Grottoes, and no unique genus with a vital contribution to the biodeterioration of wall paintings was identified.…”