Radiation p rotection r egulation aspects

1. Radiation protectionregulation aspects Anna Maria Motoc „Frédéric Joliot-Curie” National Research Institute for Radiobiology and Radiohygiene, Budapest Radiation Protection Training Course, 2016 Semmelweis University Faculty of Dentistry Department of Oral, Dental and Maxillofacial Surgery

2. Introduction Ionising radiations: • Radioactive radiations (alfa, beta, gamma) • X-rays • Neutron radiation

3. Process of induction /ionisation of atoms e- release Ionisation Radiation e- lifting Induction Energy transfer Interaction between the radiation and the matter

4. X-rays • X-rays are a type of electromagnetic radiation • can be considered as ‘packets’ of energy, called photons,which have wave properties (wavelength, frequency) • X-rays are short wavelength (λ), high frequency (ν), high energy (E) • when X-rays hit atoms their energy can be transferred, producing ion pairs in matter

5. Electromagnetic radiation IONIZING RADIATON Non-ionizing radiaion VISIBLE COSMIC MICROVAVES X-RAYS INFRARED ULTRAVIOLET GAMMA TV, RADIO Decreasing wave length Increasing frequency Increasingphoton energy

6. Dose concepts I. • Absorbed dose: • the quantity of energy deposited by the radiation per unit mass of matter • the SI unit of measurement: Gray (Gy) 1 Gy = 1J/kg • subunits: mGy, µGy, nGy 1 mGy=10-3 Gy 1 μGy=10-6 Gy 1nGy=10-9 Gy • Absorbed dose rate: • the quantity of absorbed dose per unit of time • the SI unit of measurement: Gray /second(Gy/s) • subunits: mGy/h, µGy/h, nGy/h • These quantities are measurable, but they are not a good indicator of biological damages

7. Dose concepts II. • Equivalent dose: • is the product of the absorbed dose multiplied by a radiation weighting factor • the biological effect depends on the nature of the incident radiation • the SI unit of measurement : Sievert (Sv) • Effective dose: • is the sum of the weighted equivalent doses in all tissues and organs of the body affected by the ionising radiation • the SI unit of measurement : Sievert (Sv). • the main risk is cancer induction (bone marrow, colon, lung and stomach are the most susceptible to radiation-induced malignances)

9. Direct effects Indirect effects Repair Primary damage Cell death Modified cell Damage to organ Somatic cells Germ cells Death of organism Cancer Leukemia Hereditary effects The cell Deterministic effects Stochastic effects BIOLOGICALEFFECTS Interaction of ionising radiation with living matter

10. The pathological effects of ionising radiation Radiation Energy absorbed by cells Transformation of cells Death of cells • Stochastic effects • late • constant severity • Deterministic effects • early • severity related to exposure

11. Biological effects of radiation I. • Deterministic – at high doses • are characterized by a threshold dose, below which the effect does not occur • the amount of biological damage produced depends on the total energy deposited in a cell or tissue (dose) • as dose increases the severity of the damage increases • mainly result in the killing of cells • include : skin burn, cataract induction, sterility induction, acute radiation syndrome (ARS)

12. Deterministiceffects Effect Cancer Genetic Prob  dose Cataract infertility erythema epilation Dose 500 mSv eye lenses injuries (cataract) 150 mSv for temporary sterility (males) 2500 mSv for ovarian (females)

13. Time of onset of clinical signs of skin injury depending on dose received • SymptomsDose range Time of onset • (Gy) (day) • Erythema 3-10 14-21 • Epilation >3 14-18 • Dry desquamation 8-12 25-30 • Moist desquamation 15-20 20-28 • Blister formation 15-25 15-25 • Ulceration >20 14-21 • Necrosis >25 >21 • Ref.: IAEA-WHO: Diagnosis and Treatment of Radiation Injuries. • IAEA Safety Reports Series, No. 2, Vienna, 1998

14. Biological effects of radiation II. • Stochastic– at low doses (accepted model: LNT – linear non-threshold model) • have no threshold • as dose increases the chance of an occurrence of the effect increases • include: cancer induction or hereditary effects • The body’s repair and defence mechanism makes this a very improbable outcome at (very) small doses.

15. Stochastic effects LNT – linear non-threshold model

16. Applications in the medical field I. • X-ray Imaging (analog, digital imaging) • Diagnostic/therapeutic workplaces • Conventional radiology • fluoroscopy • radiography • mammography • bone densitometry • dental radiography • Interventional radiology

17. Radioscopic equipment (fluoroscopy)

18. Mammography equipment

19. Radiographic equipment Fixed radiographic Photofluorography Mobile radiographic

20. Bone densitometry

21. Dental radiology Bitewing (intraoral) radiography Panoramic radiography

22. Computed tomography (CT)

23. Interventional radiology

24. Applications in medical field II. • Medical therapy (sealed radiation sources) workplaces • teletherapy, brachytherapy, HDR afterloading

25. Applications in medical field III. • Accelerating workplaces • medical application - therapy

26. Applications in medical field IV. • Nuclear medicine (isotope laboratory) • in vitro and in vivoisotope diagnostics • isotope therapy (I-131, Sr-89, Y-90). Hibrid SPECT/CT System

27. Radiation protection I. • Shortly after their discovery the users of X-rays and other ionising radiations realised that they may produce detrimental biological effects • The pioneers were the first (felt) victims of the radiations. They suffered injuries like skin damages, acute (chronic) radiation syndrome • Nowadays we know that this can only occur in cases of improper application

29. Hand of a dentist who for 35 years held x-ray films in place in patients' mouths. The thumb has been partially amputated. Damaged skin on the fingers has been replaced by grafts. The lesion on the finger is a skin cancer subsequently removed. Marie Curie (seated) at work with her daughter Irene. Both are thought to have died of leukemia as a consequence of theradiation exposure they receive during their experiments with radioactivity. (Courtesy of the Austrian Radium Institute and the International Atomic Energy Bulletin)

30. Radiation protection II. • An improper application of the ionising radiation may harm the health of humans and of fauna and flora, therefore damaging the environment. • In order to avoid these unwanted effects, for the control of radiation sources Radiation protectionwas created the protection against exposure to ionising radiation. • Shortly after the discovery of ionising radiations, their users realised that standards of protection had to be developed. • Due to this concern, the International Commission on Radiological Protection (ICRP) was established in 1928.

31. For the effectiveoperation of radiation protection, it is necessary to have appropriate laws and decrees. Complying with these, their revision and development can only be done based on prescribed constitutional form.

32. Organizations of International radiation protection -the main recommendations and regulations Basic documents for Hungarian regulation

33. International organizations Inter-governmental organization: • United Nations (UN) and its subsidiary organization UNSCEAR (UN Scientific Commitee on the Effect of Atomic Radiation)

34. Specialised organizations • Word Health Organization (WHO) • Food and Agriculture Organization (FAO) • International Labour Organization (ILO) IAEA - International Atomic Energy Agency Radiation protection recommendations, Publications: Safety Standards, Safety Guides, Safety Recommendations,Safety Requirements.

35. Territorial organizations: OECD-NEA, EUROATOM, CERN Expert organizations: ICRP - International Commission for Radiation Protection • ICRU-International Commission On Radiation Units and Measurements IRPA-International Radiation Protection Association IEC-International Electrotechnical Commission

36. Legislative Process InRadiation Protection ICRP Report 60 (1990) Basic Safety Standards (1996) ICRP Publication 103 (2007) EU DIRECTIVES Ionising Radiations Regulations (2000) National Legislation

37. International Regulations ICRP Publication 60. (1991) IAEA/IBSS International Basic Safety Standards for Protection Against Ionising Radiation and Safety of Radiation Sources (1996) Act No. CXVI of 1996 on Atomic Energy

38. Governmentalregulation • Governments have responsibility for the enforcement of the standard, generally through a system that includes a Regulatory Authority • National infrastructureincludes: • legislation and regulations (law and decrees) • a Regulatory Authority empowered to authorize and inspect regulated activities • sufficent resources • adequate numbers of trained personnel

39. Regulatory Authority The type of regulatory system adopted in a country depends on: • the size • complexity • safety applications of the regulated practices and sources • the regulatory traditions in the country

40. Order of radiation protection training • Acquisition of radiation protection knowleadge shall be ensured within the framework of training and upgrading training (every five years) • Subject to written and oral examination

41. Radiation protection training • depending on the degree of the risk arising from the characteristics of the work: • basic level • extended level • work in industrial, medical, radiological areas (handle the radiation source independently, or who supervise such work positions); • comprehensive level