ESTUDO DE UMA ALTERNATIVA NÃO TÓXICA E ECONÓMICA PARA INIBIÇÃO DE FUNGOS EM OBRAS E DOCUMENTOS EM PAPEL: EFICÁCIA E EFEITOS SECUNDÁRIOS

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Fungi in archives, libraries, and museums: a review on paper conservation and human health

Publication . Pinheiro, Ana Catarina; Sequeira, Sílvia Oliveira; Macedo, Maria Filomena; DCR - Departamento de Conservação e Restauro; VICARTE - Vidro e Cerâmica para as Artes; Taylor & Francis (Routledge): SSH Titles / Taylor & Francis (Routledge)

The action of fungi on books, documents, maps, and works of art on paper can result in inestimable cultural losses. Plus, some of the fungi present in paper documents, surfaces and air from archives, libraries and museums are also a threat to human health. This work aims to review the literature on the most important and frequent microfungal populations found in paper-based collections all over the world, and correlate these data with human health risks. A total of 71 studies, dating between 1997 and 2018 were reviewed and organized. From 27 different countries, 207 fungal genera and 580 species were reported. Chaetomium sp. and Fusarium sp. were found to be special contaminants in the air of archives and have been associated with paper biodeterioration. The most common fungi reported (e.g. Penicillium, Aspergillus, and Alternaria species) have an impact on paper conservation but can also cause adverse human health effects. The most frequent fungal species retrieved from discoloured paper materials are discussed in greater detail. Considerations on methods of identification and quantification of fungal contamination are also presented. Finally, the authors acknowledge an urgent need for standardizing research in this area and further studies are proposed.

2019-11-02Recensão

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Fungal biodeterioration of paper: development of safer and accessible conservation treatments

Publication . Sequeira, Sílvia Oliveira; Dinis, Maria Filomena; Cabrita, Eurico; Phillips, Allan

Great part of the History of mankind is registered in the form of documents or works of art on paper support. Paper can be deteriorated due to physical, chemical and biological agents. Within microorganisms, fungi are the major paper biodeteriogens. Throughout history, several toxic methods have been used to prevent and stop fungal deterioration on paper based materials. More recently, a growing concern about environmental and health issues has led to the research on new antifungal alternatives, with lower toxicity. However, the existent antifungal methods and compounds still have drawbacks in terms of efficacy, health hazards, damaging effects on paper, or lack of thorough testing. In this context, the present thesis focused on testing and developing accessible antifungal treatments with low toxicity, which could prevent the long term paper deterioration. The selection of antifungal compounds was made taking into account the results from a literature review on antifungals used on paper conservation, a survey to paper conservators, and a review of antifungals used in cosmetics and pharmaceutical industries, having as a basic premise their low toxicity. Aspergillus niger, Chaetomium globosum, Cladosporium cladosporioides, Penicillium chrysogenum and Penicillium corylophilum were selected as test fungal species. Fungal growth on paper was evaluated by measuring colonization areas and biomass dry weight determination. A formulation containing parabens and calcium propionate (PBs+CP) presented the best antifungal activity on paper samples, followed by a formulation containing clotrimazole and calcium hydroxide nanoparticles (CLT+NPs), and ultimately 70% ethanol (70%EtOH). Before application on cultural heritage materials, conservation treatments have to be thoroughly tested to assess if they can cause any damage on the treated materials in the short and long term. The effects of the tested formulations on paper were evaluated in terms of pH, colourimetry, folding endurance and molecular alterations, using moist heat artificial ageing. Besides plain paper, paper previously biodeteriorated by A. niger was tested in order to evaluate the potential of each compound to prevent further deterioration caused by fungal metabolites. The obtained results on biodeteriorated samples illustrate how tremendously damaging the products excreted by fungi can be in the long term. PBs+CP formulation was the only one capable of preventing long term acidification, loss of folding endurance, and discoloration caused by fungal metabolites, but on the other hand, on plain samples, this formulation caused paper discoloration. CLT+NPs formulation significantly prevented the acidification and loss of folding endurance, although causing a minor discoloration on paper at a long term. 70%EtOH had a mild positive impact in the chemical stabilization of paper and did not cause any paper discoloration. The information provided in this thesis contributes to a deeper understanding on safer options for preventing and treating paper deterioration by fungi and opens the way for further research in this challenging field of heritage conservation.

2016-04Tese de doutoramento

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Fundação para a Ciência e a Tecnologia

Número da atribuição

SFRH/BD/72216/2010