The Variation of Concepts and Recommendations on Riadiation Protection

1
The Variation of Concepts and Recommendations on
Riadiation Protection

• Reference
• C.G. Jones, A Review of the History of U.S.
  Radiation Protection Regulations,
  Recommendations, and St-andards, Health
  Physics, Vol.88 No2, p105-124,2005

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2
Introduction

• History
• X-ray, Roentgen,1896
• Radium, Becquerel, Marie Pierre Curie, 1901
• Harm
• X-ray, sterility(??),bone disease,cancer,1911
• Radium, serious illness and death, female factory
  workers, Harrison S. Martland, 1925
• State No standardized Methods for measurement of
  radiation exposure or calculation of radiation
  dose.

3
Early Recommendations (1928-1945)

• Organization
• International Advisory Committee on X-ray and
  Radium Protection,1928,---ICRP
• National (.),NCRP,1929
• Concepts
• X-ray tolerance dose, 0.2R(roentgen) per
  day,High-energy photons (internationalnational)
• Radium body burdens (National), 0.1 ,
  internal exposure
• ICRP, NCRP, bone seeking radionuclides
• To limit the exposure of radiological workers to
  levels that result in no visible effects
• Concepts and techniques for assessing radiation
  dose is in its infancy.

4
Development of Radiation Protection
Recommendations (1945-1959)

• Organization
• NCRP,1946 ICRP(?)
• AEC,Atomic Energy Commission, 1946 (Truman)
• BEARBiological Effects of Atomic Radiation,1956
• IAEAInternational Atomic Energy Agenccy,1957
• UNSCEARUnited Nation Scientific Committee on the
  Effects of Atomic Radiation,1958
• Debate concerning radiation philosophy
• BEAR(1956) genetic effects as low as possible"
• Permissible dose vs. Tolerance dose

5
Development of Radiation Protection
Recommendations (1945-1959)

• Changes in Recommendations
• Decrease of the permissible dose
• Dose limit to critical organs.
• Exposure limit for the public (1/10 of the
  workers, 1954)
• Special units of Radiation Measurement
• raddescribes absorbed dose to 100ergs per gram
  of human tissue
• remreontgen equivalent man
• Concepts for internal models

6
Congressional Interest and Formulation of the
Federal Radiation Council and NCRP(1959-1974)

• Organization
• FRC Federal Radiation Council,1959
• NCRP National Council of Radiation Protection
  and Measurement,1964
• EPA Environmental Protection Agency,1970
• Knowledge
• 1960,RPGs,FRC,Radon in uranium mines, WL,WLM
• 1968,FDA,radiation from machines
• 1971,AEC,as low as practicable --gt ALARA
• 1972, BEIR,BEIR?,No dose threshold with respect
  to low dose response

7
A New Regulatory Era (1974 to Present)

• ICRP Publication 26 ---Risk based system
• Principles
• Justification of practices
• Optimization of doses
• Limitation of risk
• Concepts
• Effective dose equivalent (combine internal and
  external exposure)
• Stochastic effect departure from threshold
  effect (deterministic effect)
• Linear hypothesis
• Risk factors (use to derive dose limits from a
  limit on annual risk.)

8
A New Regulatory Era(1974 to present)

• ICRP Publication 60,1991
• Still embraces the concept of
• Optimization, Justification, Limitation
• Effective Dose and Equivalent Dose
• Quality factor (Q) ? Radiation weighting factor
  (WR)
• Reduction of dose limit
• For radiological workers(50mS--gt20mSv) per year.