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NKS TODAY AND TOMORROW 20 - 21 MARCH, ROSKILDE, DENMARK RADIOLOGICAL PROTECTION AT THE START OF THE 21ST CENTURY: A PROGRESS REPORT. Roger H Clarke, Chairman, ICRP. THE FIRST PHASE 1895 - 1955.
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NKS TODAY AND TOMORROW20 - 21 MARCH, ROSKILDE, DENMARKRADIOLOGICAL PROTECTION AT THE START OF THE 21ST CENTURY:A PROGRESS REPORT Roger H Clarke, Chairman, ICRP
THE FIRST PHASE1895 - 1955 Protection was concerned with keeping INDIVIDUAL WORKERS below the THRESHOLDS for deterministic effects No SOCIETAL concerns, indeed low doses deemed beneficial and consumer products abounded
THE MIDDLE PHASE1955 - 1990 UTILITARIAN* ethics applied classical Cost- Benefit Analysis to address the question - ‘How much does it cost and how many lives are saved?’ The use of Collective Dose emphasised the protection of SOCIETY and the inability to take account of individual risk *‘The doctrine that the greatest good of the greatest number should be the guiding principle’ - Oxford English Dictionary
1990 RECOMMENDATIONS ON OPTIMISATION ‘This procedure should be constrained by restrictions on the doses to individuals (Dose Constraints),….., so as to limit the inequity likely to result from the inherent economic and social judgements.’
CURRENT PHASE1990 - Recommendations since 1990 are in terms of - firstly restrictions on individual dose - then a requirement to optimise A shift from UTILITARIAN values, so as to include the recognition of individual rights by usingEGALITARIAN* ethics, an equity-based system * ‘Holding the principle of equal treatment for all persons’ - Oxford English Dictionary
MAIN COMMISSION 2001-5 FRED METTLER LARS-ERIK HOLM RUDOLF ALEXAKHIN ROGER COX BERT WINKLER YASUHITO SASAKI CHRISTIAN STREFFER ABEL GONZALEZ JOHN BOICE ANNIE SUGIER PAN ZI QIANG GRETA DICUS ROGER CLARKE
RISKS AT LOW DOSES AND LOW DOSE RATES -is there a threshold below which repair is totally effective? -are low doses more dangerous than we currently assume? Epidemiology alone cannot answer these questions, so support is needed from molecular studies
THE ‘LNT’ HYPOTHESIS above the prevalent background dose, an increment in dose results in a proportional increment of risk
JUSTIFICATION The practice leading to an exposure must produce an overall benefit It is a policy matter for decision makers, -with radiological protection issues being a minor input For medical doctors, it is a matter both of the generic procedure and then the individual referral
PRINCIPLES OF PROTECTIONfor generically justified medical procedures Justify the examination individual-based criterion Optimisation Reference Levels as indicators of good practice
PRINCIPLES OF PROTECTIONFor a justified practice or for an environmental source Protective Action Levels basic levels of health protection for the individual Optimisation the optimum level of health protection for a given source
PROTECTIVE ACTION LEVELS PEOPLE 10 x AVERAGE NATURAL BACKGROUND DISCHARGES 0.1 x EXCLUSION 0.01 x
OPTIMISATION OF PROTECTION The ‘stakeholder’ process of involving most affected individuals is an important approach -EMPOWER THE WORKFORCE -ENGAGE THE PUBLIC(S) -Leading to the optimum level of health protection
RECOMMENDATIONS FOR THE START OF THE 21st CENTURY(i) • Develop the System of Protection • - describe the Ethical Basis • Define doses of interest for risk • - few mSv/a • Justification • - for practices, • - medical exposures to be separate • Protective Action Levels • - based on natural background • Optimisation • - replace differential equations with common sense
RECOMMENDATIONS FOR THE START OF THE 21st CENTURY(ii) Definition of an individual - revisit critical group Stakeholder involvement - how is this to be achieved Natural radiation exposures - philosophy as for radon? wR and wT - values for Effective Dose Protection of the Environment - policy needed Regulatory guidance - not prescriptive, but flexible
OVERALL CONCLUSIONS Before the 1950s - protect workers 1960s to 1990s - Utilitarianism and cba Currently - shift to Egalitarianism PROTECTION AT THE START OF THE 21ST CENTURY Use the existence of natural background to set PROTECTIVE ACTION LEVELS and simplify, engage, explain