Underground Radiobiology: A Perspective at Gran Sasso National Laboratory.

Area of Science:

• Radiobiology
• Radiation Protection
• Environmental Science

Background:

• The Linear No-Threshold (LNT) model is standard for radiological protection, extrapolating high-dose radiation effects to low doses.
• Radiobiology studies in Deep Underground Laboratories (DULs) provide data challenging the LNT model at low doses and dose rates.
• DULs offer ultra-low radiation environments ideal for below-background radiobiology experiments.

Purpose of the Study:

• To investigate biological responses to low-dose radiation that may contradict the LNT model.
• To explore the potential for environmental radiation to trigger adaptive stress responses.
• To analyze the specific role of the gamma radiation spectrum in biological effects.

Main Methods:

• Conducting radiobiology experiments in Deep Underground Laboratories (DULs), including the INFN Gran Sasso National Laboratory (LNGS).
• Utilizing model organisms such as *Drosophila melanogaster* (fruit flies) for *in vivo* studies.
• Implementing experiments like RENOIR to characterize radiation spectra and biological responses.

Main Results:

• Data from DULs suggest that low-dose radiation can activate biological mechanisms enhancing stress coping capabilities.
• Studies using various organisms (protozoa, bacteria, cells, flies, worms, fish) indicate a potential hormetic effect.
• Open questions remain regarding radiation quality, biological endpoints, and organism-level effects.

Conclusions:

• Radiobiology research in DULs offers critical insights into low-dose radiation effects, potentially refining current radiological protection models.
• Environmental radiation may play a role in adaptive responses, warranting further investigation into its mechanisms and spectrum dependence.
• The RENOIR experiment at LNGS aims to clarify the specific impact of gamma radiation on *Drosophila melanogaster*.