Biological measurement of damage occurring to the inner structure of paper after gamma irradiation

Biological Measurement of Damage Occurring to the Inner Structure of Papere after Gamma Rays Irradiation The starting point for the reported experiment was the fact that cellulosolytic microfungi show a better growth on deteriorated paper than on paper which is well preserved. The intention was to find out if fungal biomass developed on paper can constitute a useful parameter in order to evaluate paper chemical and physical conditions. To this purpose, colorimetric measurements were carried out on paper that had been inoculated with Penicillium chrysogenum after a previous exposure to increasing ionising gamma radiation doses. It seems that there is a good correlation between the radiation dose absorbed by the paper and the values of the chromatic coordinates of the CIE L*a*b* system, b*, indicating yellowing, giving the clearest result. Collateral information from the experiment confirm that low radiation doses (up to 10 Gy), as they are needed to disinfect/disinfest paper from biodeteriogenic organisms, can not significantly damage its substrate. Authors intend to deepen this research in order to elaborate a simple and standardized method for describing the state of damage caused in paper. This method could be applied also in other fields like food irradiation to recognize a fraudulent irradiation.