1. Dr Zbigniew Zimek
Centre of the Radiation Chemistry and Technology, Institute of Nuclear Chemistry and Technology
Title: “Ionizing radiation sources used in the process of radiation sterilization”
The presentation introduced the scientific discoveries that initiated the popularization of nuclear methods in science, medicine and industry. The idea of radiation sterilization based on the use of ionizing radiation is derived from the work of Maria Skłodowska-Curie, published in 1929, where a mathematical analysis of the bactericidal activity of gamma radiation of radium was described. After many years of using the process on an industrial scale, it turned out that radiation sterilization best meets the expectations for various sterilization methods.
The basic mechanisms of the interaction of ionizing radiation on matter was discussed, and the principles of operation of sources emitting ionizing radiation in the form of an electron beam, gamma radiation flux and X-ray flux were given. The principles and mechanisms of operation of individual sources used for the radiation sterilization process were given as well. Examples of technical solutions enabling the process to be carried out on a mass scale were described. Technical and economic parameters characterizing electron accelerators, gamma sources and devices related to the emission of X-ray were compared.
2 Dr . Sylwester Sommer
Centre of Radiobiology, Institute of Nuclear Chemistry and Technology
Title a: “Microbiological aspects of the process of radiation sterilization with the emphasis of virus sterilization possibility”
Biological effects of ionizing radiation were presented (DNA and RNA damage and repair). Differences in biological effects of radiation between microorganisms and the higher organisms (humans and biota) were emphasized. Radiosensitivity of bacteria, viruses and the other microorganisms was described and compared in relation to the differences in their structure, and the possibilities of sterilization the particular groups of microorganisms with radiation were considered with special attention on the viruses sterilization. The levels of sterility described in terms of SAL (Sterility Assurrance Level) was also explained. The newest data showing ability of sterilization of PPE by means of ionising radiation was shown.
Title b: “Low dose of radiation chest therapy – is it possible and effective in case of Covid-19?”
The main causes of death from Covid-19 infection is Acute Respiratory Distress Syndrome (connected with Cytokine Release Syndrome) and in the consequence lungs failure. The idea of modifying the functioning of the immune system in lungs by means of lungs irradiation with low dose (single dose of approximate 0.5 Gy) was born. Such treatment may save lives in a severe course of disease related to the respiratory system. The idea is based on the positive outcome of the similar radiation treatment of pneumonia in the first half of the 20th century and from experiences during the radiation treatment of a rheumatoid arthritis, where there is a modification of the immune system recorded.
3. DSc. (Dr hab.) eng. Krystyna Cieśla:
Centre of the Radiation Chemistry and Technology, Institute of Nuclear Chemistry and Technology
Title: “Ionising radiation influence on the physico-chemical and functional properties of the materials” (45 min lecture + 10 min Q/A)
The problems of the possible desirable and undesirable changes of the functional properties of the particular materials that might occur under sterilization process were described. In particular, phenomena of degradation, oxidation and crosslinking of polymers were discussed together with the methodology applied for preservation or improvement of the materials under irradiation. Beside to general knowledge, the example works carried out in INCT, or in co-operation with INCT, were shown.
4. Dr. eng. Andrzej Rafalski:
Centre of the Radiation Chemistry and Technology, Radiation Sterilization Plant, Institute of Nuclear Chemistry and Technology
Title: “Radiation sterilization of medical equipment, personal protection equipment, and the other microbiologically infected objects”.
Radiation sterilization, including the levels of sterility described in terms of SAL (Sterility Assurance Level) was described. Comparison of different sterilization methods of healthcare products (Gamma, e-beam, X-ray and Ethylene Oxide Technologies) was shown. Practical application of ionising radiation for sterilization of various medical equipment (including transplant materials, scaffolds for tissue engineering, disposable materials, dressings), personal protection equipment (i.e. masks, protective coveralls), and the other microbiologically infected objects was shown The works carried out in Radiation Sterilization Plant of INCT was presented.