New trends in disinfection and disinfestation of historic paper items

Abstract

Fungi and bacteria as well as insects, mainly larvae of beetles and silverfish, cause frequently significant deterioration of paper-based cultural property. The combating of the biological pests which damage historic paper items with chemical biocides has been applied since the fifties of the twentieth century. However, subsequent years brought disappointment with the excessive use of biocides because more and more attention was attracted to their harmfulness to human health, environment and sometimes also to historic matter. Meanwhile, in many countries in Europe, such as Germany or the Netherlands, and in North America (Canada, USA) practitioners of cultural heritage conservation resign from the disinfection of paper based historic items or it is limited to the objects very strongly affected by microorganisms and then the γ radiation or 70% water solution of ethanol are recommended. In Poland the examinations of vitality of the combated microorganisms before disinfection and sensitivity of the historic item against the biocide are recommended. The disinfestation of the historic paper items is now carried with the fumigation in modified atmosphere containing 99.9% nitrogen. The disinfestation takes appr. 3 weeks and provides the killing of the insects in every developmental stage without the necessity of using toxic chemicals. The dimensions of the special plastic disinfestation chambers can be adjusted depending on the dimensions of the objects and during the treatment the required relative humidity of the atmosphere, i.e. appr. 55%, is maintained inside. Disinfestation treatments using modified atmosphere have been available also in Poland for several years.