X-ray sterilization of insects and microorganisms for cultural heritage applications

摘要: Abstract The APAM (Development of Particle Accelerators and Medical Applications) Laboratory the ENEA Frascati Research Center is engaged in preservation cultural heritage as part COBRA (Sviluppo e diffusione di metodi, tecnologie strumenti avanzati per la COnservazione dei Beni culturali, basati sull’applicazione Radiazioni Abilitanti) project addressed to transfer innovative technologies methodologies from research small medium enterprises involved restorative measures. This work aims demonstrate effectiveness ionizing radiation on disinfection biodegraded art objects. conventional methods for disinfestation works art, using chemicals toxic humans environment, might cause some damage treated material even micrometric scale (i. e. either cellulose degradation). Ionizing radiations interact with infesting biological causing an irreversible DNA degradation. For this reason, they are certainly suitable removal treatments both macro organisms bacterial colonies. A 4.8 MeV electron linear accelerator, normally dedicated characterization dose detectors radiographies, has been employed produce Bremsstrahlung X-rays through a lead converter. spectral fluence source calculated Monte Carlo MCNPX code. dosimetric field made radiochromic films sensitive range our interest (from 50 500 Gy) calibrated Markus ionization chamber. irradiation artifact prototypes within shielded room at variable distance source. Samples subjected consist soil bacterium, Agrobacterium rhizogenes , insect, Stegobium paniceum that found wall paintings invasive coloniser pest books, wood paintings, respectively. Tests have performed well woods mock-ups evaluate potential during sterilization. growing capacity cells re-cultured end treatment was evaluated sample resulted strongly inhibit cell growth post-irradiation incubation, so after incubation periods 28 °C, no significant observed. induced levels insect mortality sterility vs absorbed operative conditions also evaluated, demonstrating induction full since lower 40% by two days higher treatment. experiments proved ability efficaciously treat objects order prevent increase biodeterioration without damaging materials: fact, mechanical tests irradiated not demonstrated absence any degradation exposition.