Unveiling the Occupational Exposure to Microbial Contamination in Conservation-Restoration Settings

Abstract

Assuring a proper environment for the fulfillment of professional activities is one of the Sustainable Development Goals and is contemplated in the One Health approach assumed by the World Health Organization. This particular study is applied to an often neglected sector of our society-the conservators/restorers-despite the many health issues reported by these professionals. Three different specialties (textiles, paintings and wood sculpture) and locations were selected for evaluation by placement of electrostatic dust cloths. After treatment of the samples, bacterial and fungal contamination were assessed, as well as mycotoxin determination, the presence of azole-resistant strains and cytotoxicity of the microorganisms encountered. Bacteria were only present in one of medias used and showed relatively low numbers. The highest level of contamination by fungi was identified in one of the textiles settings. The textile area also showed the highest variability for fungi. Aspergillus sp. are one indicator of possible environmental issues, and A. sections Fumigati and Circumdati were particularly relevant in two of the settings and identified in all of them. No mycotoxins were detected and the large majority of the fungi identified were non-cytotoxic. Overall, these can be considered low-contaminated environments but attention should be given to the Aspergillus sp. contamination. Additional studies are needed not only to make these results more robust, but also to test if the environmental sampling alone is the best approach in a setting where there is very little movement and dust displacement and where professionals are in very close proximity to the artefacts being treated, which may suggest the existence of a micro-atmosphere worth evaluating and comparing to the obtained results.

Keywords: Aspergillus; azole resistance; cytotoxicity; mycotoxins; occupational exposure assessment.

Figure 1

Sampling locations, OE1 and OE4 for textiles, OE2 for sculpture and OE3 for the painting’s restoration studio.

Figure 2

Example of one of the EDCs placed at the assessed locations. A request for non-disturbance accompanies the EDC.

Figure 3

Bacterial contamination in the four sampled locations observed in TSA. On the top right is the boxplot for comparison of bacterial contamination in TSA medium between sampled areas (excluding OE2, since it has a single record). * severe outlier.

Figure 4

Total fungal counts on MEA and DG18 in samples from different areas (CFU·m⁻²·day⁻¹). Boxplot for comparison of fungal contamination in MEA (A) and DG18 (B) media between sampled areas (excluding the sculpture area (OE2), since it has a single record).

Figure 5

Fungal qualitative distribution in both MEA (dotted circles) and DG18 (full circles). Assigned to each circle is the percentage each genus occupies within the total results.

Figure 6

Aspergillus sections distribution by media and sampling place.

Figure 7

Fungal contamination (by azole screening method) per local (CFU·m⁻²·day⁻¹). SDA = Saboraud dextrose agar; ICZ = itraconazole; VCZ = voriconazole; PSZ = posaconazole. Please mind the different scale used in OE4.

Figure 8

Boxplot for comparison of fungal load in SDA (A), ICZ (B), VCZ (C) and PSZ (D) between sampled areas (excluding the sculpture area (OE2), since it has a single record). Please note the different scales used. * severe outlier; ° moderate outlier.