EFFECT OF GAMMA-RAYS ON PURE CELLULOSE PAPER AS A MODEL FOR THE STUDYOF A TREATMENT OF BIOLOGICAL RECOVERY OF BIODETERIORATED BOOKS

The effects of increased doses of gamma rays on cellulose paper (Whatm an n(o) 1) were tested under different experimental conditions, before and after accelerated ageing. The polymerization degree, tensile stre ngth, internal tearing resistance and pH were measured following the s tandard procedures: the L lightness factor and the a* and b* chromati city co-ordinates were also determined. The results showed the irradia tion treatment to have a negative effect both on the polymerization de gree and on yellowing. The effect, comparable to accelerated ageing of paper, depends on the dose absorbed. Before accelerated ageing the te nsile strength and degree of acidity do not seem to be affected even b y high doses of radiation. The effect of the gamma rays was also compa red with some measurements on another Disinfection/Disinfestation syst em: fumigation with Ethylene Oxide. Treatment with commonly used conce ntration of Ethylene Oxide has no negative effects on the parameters w e 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 ra ys in the biological recovery of biodeteriorated books. This assessmen t has to take into account the effective weight of certain parameters analysed in relation to subsequent conservation of material and, on th e other hand, the need to intervene urgently on those books at particu lar risk of biological attack.