Effect of gamma rays on pure cellulose paper as a model for the study of a treatment of "biological recovery" of biodeteriorated books

The effects of increased doses of gamma rays on cellulose paper (Whatman n(o) 1) were tested under different experimental conditions, before and after accelerated ageing. The polymerization degree, tensile strength, internal tearing resistance and pH were measured following the standard procedures: the L* lightness factor and the a* and b* chromaticity co-ordinates were also determined. The results showed the irradiation treatment to have a negative effect both on the polymerization degree and on yellowing. The effect, comparable to accelerated ageing of paper, depends on the dose absorbed. Before accelerated ageing the tensile strength and degree of acidity do not seem to be affected even by high doses of radiation. The effect of the gamma rays was also compared with some measurements on another Disinfection/Disinfestation system: fumigation with Ethylene Oxide. Treatment with commonly used concentration of Ethylene Oxide has no negative effects on the parameters we measured, but this treatment will probably soon be banned in Italy, as has already occurred in other countries. Thus we need to assess the feasibility for the future of treatment with low doses of ionizing rays in the biological recovery of biodeteriorated books. This assessment has to take into account the effective weight of certain parameters analysed in relation to subsequent conservation of material and, on the other hand, the need to intervene urgently on those books at particular risk of biological attack.