50 Years of Federal Radiation Protection Guidance – What’s Left To Do?

NCHPS Spring MeetingMarch 4, 2010

Presented by Mike BoydUS EPA Radiation Protection Division

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Credit where credit is due –

I owe my career in Health Physics to my mentor,

Dr. Jim Watson.

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What is Federal Guidance?

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What Is Federal Guidance?

The Federal guidance function is to "...advise the President on radiation matters, directly or indirectly affecting the public, including guidance for all Federal agencies in the formulation of radiation standards...”

- Authority transferred from Federal Radiation Council to EPA Administrator in 1970

- President signs final guidance

EPA has used Federal Guidance to

- Set New Limits for Uranium Workers

- Set Revised General Standards for Workers

- Issue Guidance on the Use of Diagnostic X-rays

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Two Kinds of Federal Guidance

Presidential Guidance

• Radiation protection principles and policy recommendations to Federal agencies

• Signed by the President

Technical Reports

• Methodologies and coefficients for radiation dose and risk assessments

• Background information to support Presidential Guidance and standards

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Two Kinds of Federal Guidance

Federal Guidance

Presidential GuidanceTechnical Guidance

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History of Federal Guidance1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

Radiation Protection

Guidance for Federal Agencies: EISENHOWER

1960 (FRC)

Underground Mining of U Ore: NIXON

1970 (FRC)

Supplemental FG: KENNEDY

1961 (FRC)

Guidance on Diagnostic X-rays:

CARTER 1978 (EPA)

Guidance for Occupational

Exposure (revised 1960 guidance): REAGAN 1987 (EPA)

Tech. Reports 1, 2, 5, & 7 Background for Rad. Protection Stds. 1960, 61, 65 (FRC)

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Tech Reports 3, 4, 6 Fallout Studies 1962,

63, 64 (FRC)

Tech. Report 8 Guidance for Control of

Hazards in U Mines 1967 (FRC)

Tech. Report 11 ALIs,

DACs, & DCFs (current, ICRP

26) 1988 (EPA)

Tech. Report 13 Cancer Risk Coefficients

1999 (EPA)

Tech. Report 12 External Exposure DCFs

1993 (EPA)

Tech. Report 9 Background for

Diagnostic X-ray Guidance 1976 (EPA)

Tech. Report 10 Radioactive

Concentration Guides (out of

date) 1984 (FRC)

Technical ReportsPresidential Guidance

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Current FG Technical Reports

FGR 9 FGR 11 FGR 12 FGR 13

SubjectDiagnostic

X-ray Guidance

Internal DCFS- Ingestion- Inhalation

External DCFs

Cancer Risk Coefficients

International Consensus

BasisICRP 26/30

ICRP 26/30

ICRP 60+

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Science Behind the Federal Guidance

Biological Effects of Ionizing Radiation (BEIR)• Reports by US National Academies of Science• Seven to date. Reports IV and VI describe risk from

alpha-emitting radionuclides, including radon• Reports III, V, and VII describe risk from low linear

energy transfer (LET) radiation such as photons

United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)

• Sources, Effects and Risks of Ionizing Radiation• Fifteen reports 1955 – 2006• Ongoing work

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1010

Significant ICRP Recommendations and Physiological Model/Data Table Publications

ICRP 2 and 10 (1960’s)

ICRP 26 and 30 (multiple parts) (1976 -1980’s)

ICRP 60 + 66, 68, 72 et al (1990 – 2005)

ICRP 103 (2007) + documents being developed (through

2012 or later)

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FGR 11: Internal Dose Coefficients

FGR 11 dose conversion factors (DCFs) used to calculate effective dose to reference adult from ingestion and inhalation of 800+ radionuclides (Sv/Bq)

Provides ALIs and DACs

FGR 11 dosimetry is out of date (based on ICRP 26 and 30 from 1976); but still needed to comply with some US regulations

More recent ICRP 60+ DCFs can be found on FGR 13 CD Supplement

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Ideas for Revising FGR 11

Provide effective dose for Reference Worker and Reference Individual (both gender averaged)?

• Worker is adult only

• Individual is age-averaged for US population

Provide age-,gender-, and organ-specific equivalent doses?

Provide updated ALIs and DACs?

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FGR 12: External Dose Coefficients

FGR 12 DCFs used to calculate effective dose to reference adult from exposure to radionuclide concentrations in soil, air and water

Work is currently underway to update FGR 12 with addition of age- and gender-specific DCFs

New DCFs will reflect latest decay data in ICRP Publication 107 (replaces ICRP 38)

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Radiation Risk Assessment

Activityin Body

RadiationDose tothe Body

DosimetryModels

HealthEffectsStudies

RiskModels

RiskCoefficient

(RC)

BiokineticModels

IntakeAssumptions

OAK RIDGE NATIONAL LABORATORYU. S. DEPARTMENT OF ENERGY

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DCAL Internal Emitters Calculations

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FGR 13: Cancer Risk Coefficients

FGR 13 gives risk per becquerel for food ingestion, water ingestion, and inhalation

Gives risk/year of exposure per becquerel/ gram of radionuclides in soil

Revision based on BEIR VII is in the early stages (expected ~ 2012 or later)

Current FGR 13 values in units of picocuries are available in EPA’s Health Effects Assessment Summary Tables (HEAST)

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FGR 13 CD Supplement

CD Supplement includes all the data files used to calculate risk coefficients in FGR 13

A data viewer allows the user to look up age-, gender-, and organ-specific risks per radionuclide

ICRP 60+ dose coefficients are also available on the CD Supplement

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FGR 9: RP Guidance for Diagnostic X-rays

Guidance only applies to use of medical/dental x-rays in federal facilities (HHS, VA, DoD)

1976 guidance based on film radiography (film overexposure provided ALARA incentive)

Digital radiography, CT, and interventional fluoroscopy can give sizable doses creating a concern for increased latent cancer risk

Goal is to choose the appropriate imaging procedure and give the dose necessary for proper diagnosis – and no more!

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Sources of Radiation Exposure (NCRP Report #160, 2009)

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So, What’s Left To Do?

As already mentioned, EPA is or will be updating Federal Guidance Reports 9, 11, 12, and 13

FGR 9 and 12 will be completed in late 2010 or early 2011

FGR 13 is now scheduled for completion in 2013

FGR 11 may be ready in late 2012 or 2013, since organ dose information needed for new risk coefficients in FGR 13

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What Else Is Left To Do?

Federal Guidance for the General Public• Current Guidance signed by Pres. Eisenhower in

1960

• Sets public dose limit of 500 millirems/year

• Draft proposal considers 2 options – 100 millirems/y with exceptions (e.g., radon) OR non-numerical approach requiring agencies set individual source limits using optimization principle

• Most agencies now make reference to ICRP/NCRP 100 mrem/y as all-sources limit

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And still more possibilities….

Revised Occupational Presidential Guidance?

Embryo and fetus dose and risk coefficients?

Dermal absorption dose coefficients?

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To quote Dr. Watson, “Do you have any questions?”