Gamma radiation dose rate in controlling fungi treatments to preserve organic artifacts

In recent decades, applying irradiation techniques for controlling fungi and preserving organic cultural heritage has garnered increasing interest. Fungi, recognized for their resilience to various environmental conditions, pose a significant threat to organic cultural artifacts. Previous research has indicated that most fungi are disinfected at 5 kGy. However, highly radiation-resistant fungi have been observed after 7–8 kGy of gamma irradiation. Nonetheless, variations in fungi growth rates and variable effects on microorganisms due to variable dose rates per hour of irradiation from different irradiation facilities—even when the total absorbed dose remains constant—have been documented. In this study, Epicoccum nigrum, known for its high radiation tolerance was completely controlled at 15 kGy dose with 2 kGy/h dose rate, Cladosporium cladosporioides at 10 kGy dose with 3 kGy/h dose rate. Also we detected the critical lethal dose of radiation for each fungus in the water-logged traditional Korean calligraphy, which is drawn on a type of paper that combines silk and Hanji (Korean art piece).