The following issues were discussed during the webinars: • Nature of ionising radiation, the principles of operation of sources emitting ionizing radiation, basic mechanisms of the interaction with matter and comparison of the influence of various radiation types (gamma rays, fast electrons, X-rays); • Biological effects (DNA damage and repair). Microbiological aspects of the process of radiation sterilization with the emphasis of virus sterilization possibility; • The idea of modifying the functioning of the immune system in lungs by means of lungs irradiation in regard to COVID infection; • Radiation sterilization, including the levels of sterility described in terms of SAL (Sterility Assurrance Level) accompanied by comparison of different sterilization methods of healthcare products (gamma, e-beam, X-ray, Ethylene Oxide Technologies, etc.); • The possible desirable and undesirable changes of the functional properties of particular materials that might occur under sterilization processing and the methodology applied for preservation or for favourable modification of the materials under irradiation; • Practical use of radiation technologies for sterilization and for production of sterile materials with new or improved functionalities. The examples of medical equipment, PPE and the other microbiologically infected objects subjected to decontamination by a use of ionising radiation were shown. • Validation of the sterilization process.