Eliminating fungi, larvae, insects and bacteria
2026 editorial revision
Irradiation with gamma rays also protects ancient objects from deterioration by eliminating fungi, larvae, insects and bacteria. Gamma rays from cobalt-60 are a particularly effective tool for eliminating mould and parasites at low temperatures and with a high degree of reliability.
From a biological point of view, intense gamma radiation causes damage to DNA molecules, which contain the genetic information of microorganisms. It interacts with the entire cell, leading to the destruction of the organisms.
The radiation is highly penetrating and irradiates the entire volume being treated. It does not require the use of chemicals and is carried out at ambient temperature and pressure. An object does not need to be removed from the packaging used to transport it. Mummies can remain in their sarcophagi.
Mummy of Ramesses II
In 1977, the Cairo Museum found that the mummy of Pharaoh Ramesses II was infested with larvae and fungi. It asked France and the CEA for help in treating the mummy by irradiation. This was preceded by numerous tests, particularly on other mummies, to verify that the treatment was harmless. It should be noted that the Republican Guard was present when the pharaoh’s mummy arrived (as befitted a head of state). The treatment required the mummy, sarcophagus and its base to be transported from the Cairo Museum to Saclay and back (it had been decided not to go as far as Grenoble), in a sterile enclosure. © CEA
Simple disinfection, a curative treatment, requires objects to be irradiated for a relatively short period of time. Sterilisation requires significantly more intense irradiation. The radiation dose must be adapted to the type of parasites to be destroyed. Thus, disinfection takes from one to a few hours, whereas sterilisation requires around twenty hours. For example, 500 Grays (Gy) are required to sterilise wood-boring insects and 2,000 Gy to stop the growth of certain fungi, while 10,000 Gy or more are required for sterilisation.
This technique is particularly suitable for disinfecting furniture, statues, ethnographic objects, mummies, etc…
Some other examples of treatment: This was the case of the baby mammoth (Khroma) discovered in Siberia in 2010 © Arc-NUCLEART
Some other examples of treatment: Polychrome wooden statuettes of apostles and angels, 17th century, municipality of Le Pègue (Drôme). © C. Albino/Arc-NUCLEART