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ICRP 103 Ny basisrekommendasjon fra den

internasjonale strålevernskommisjonen

Tor Wøhni

Gardermoen 17 november 2008

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ICRP-103

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ICRP-103

• Erstatter ICRP 60 som kom i 1991.

• Som igjen erstattet ICRP-26 som kom 1977

• En del nytt i forhold til ICRP-60

• Har vært gjennom flere omstendlige høringsrunder.

• Eget Annex vedr. biologisk og epidemiologisk informasjon

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Endringer fra ICRP 60 (1991)

Oppdaterte data vedrørende cancerstatistikk, litt redusert cancerrisiko

Betydelig redusert risiko for arveskader (faktor 6-8)

Reviderte organvektfaktorer (Wt)

Reviderte strålevektfaktorer (Wr). Uendret Wr for fotoner

Uendrete dosegrenser: 20 mSv for arbeidstakere, 1mSv for generell befolkning.

ingen endring i de basale prinsipper, dvsberettigelseoptimaliseringdosegrenser

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ICRP 103 Annex B - Dosimetriske størrelser

Effektiv dose beholdt: E = ∑

Wt ∙

organdose

• ”the primary use of effective dose is for demonstrating complience with dose limits, i.e. for regulatory purposes. E should not be used for epidemiological purposes or assessment of cancer probability”

• ”The assessment and interpretetation of effective dose from medical exposure of patients is problematic when organs and tissues receive only partial exposure or of very heterogenous exposure, which is the case especially with diagnostic and interventional procedures.”

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ICRP 103 Annex B - Dosimetriske størrelser Kollektivdose

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Definisjon av arbeidstakere.

Forslag til revisjon av Strålevernforskriften.

Yrkesmessig eksponering: Eksponering som arbeidstakere utsettes for i forbindelse med sitt yrke, der strålekilden og/eller eksponeringssituasjonen er en påregnelig del av yrkesutøvelsen og knyttet til denne. Begrepet får ikke anvendelse i forhold til radon. Øvrige arbeidstakere er underlagt dosegrensene for allmennheten.

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Limits versus constrains

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Annex A - health risk

Representerer en oppsummering (state of the art) vedrørende helseeffekter (vevskader, cancer, arveskader, non-cancer disease, etc.)

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Akutte stråleskader - terskelverdi

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Letale doser

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Cancer risiko

• Beregninger av krefrisiko baseres først og og fremst på Japanese Life span study (LSS - Hiroshima og Nagasaki) . Gjelder for store doser over kort tid.

• Risikotall fra LSS redusert med en faktor 2 (DDREF-faktor), for å få risikotall for små doser (< noen 100 mSv) over lang tid.

• (A187): ”On this basis it is recommended that the LNT model, combined with a judged value of DDREF for extrapolation from high doses, remain a prudent basis for the practical purposes of radiological protection at low doses and low dose rates”.

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Annex A cancer risk• Life Span Study Report 13• Studies of mortality of atomic bomb survivors. Report 13: Solid

cancer and noncancer disease mortality: 1950-1997 Preston DL, Shimizu Y, Pierce DA, Suyama A, Mabuchi K RERF Report No. 24-02 Radiat Res 160(4):381-407, 2003 Summary This continues the series of general reports on mortality in the cohort of atomic bomb survivors followed up by the Radiation Effects Research Foundation. This cohort includes 86,572 people with individual dose estimates, 60% of whom have doses of at least 5 mSv. We consider mortality for solid cancer and for noncancer diseases with 7 additional years of follow-up. There have been 9,335 deaths from solid cancer and 31,881 deaths from noncancer diseases during the 47-year follow-up. Of these, 19% of the solid cancer and 15% of the noncancer deaths occurred during the latest 7 years. We estimate that about 440 (5%) of the solid cancer deaths and 250 (0.8%) of the noncancer deaths were associated with the radiation exposure. The excess solid cancer risks appear to be linear in dose even for doses in the 0 to 150-mSv range

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ICRP-103 - Annex A Sex averaged cancer risk

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ICRP 103 – Annex A Sex specific cancer risk

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Vevsvektfaktorer Risikokoeffisienter (% per Sv)

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• Interactive RadioEpidemiological Program

NIOSH-IREP v.5.5.2

For Estimating Probability of Cancer Causation for Exposures to Radiation

To begin by manually entering required inputs To begin by using a NIOSH-provided input file • NIOSH-IREP was created for use by the Department of Labor for adjudication of claims in accordance with

the Energy Employees' Occupational Illness Compensation Program Act of 2000 (EEOICPA). NIOSH-IREP was adapted from the National Institutes of Health's (NIH) Interactive RadioEpidemiological Program (IREP) developed by the National Cancer Institute (NCI) to update the NIH Radioepidemiological Tables of 1985.

(The version of IREP developed by NCI is known as NIH-IREP.)

NIOSH-IREP v.5.5.2, introduced on June 13, 2007, increases the capabilities of the Multiple Primary Cancer calculation from being able to handle 12 primary cancers to being able to handle up to 120 primary cancers.

The PC results from v.5.5.2 are identical to those calculated using the previous version of NIOSH-IREP. Click here for more details about the modifications made to version 5.5.2 and to other recent versions. Comments

and suggestions should be communicated directly to NIOSH . ABOUT SSL CERTIFICATES

With modeling support from:

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• Claimant Information Used In Probability of Causation Calculation: • Birth Year: 1948 • Year of Diagnosis: 1997 • Cancer Model: Stomach (151) N/A

• General Exposure Information: • Exposure Year : 1977• Organ Dose : 22 mSv• Exposure Rate : Acute• Radiation Type : photons E=30-250keV

• Probability of Causation (PC) • 1st percentile 0.00 % • 5th percentile 0.01 % • 50th percentile 0.69 % • 95th percentile 8.45 % • 99th percentile 16.27 %

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Embryo

• Severe mental retardation, 8- 15 weeks, threshold of 300 mGy.

• IQ-reduction . No effect of clinical significance below 100 mGy, i.e. consistent with ICRP-60.

• Malformation: Absence of risk for induced malformations below 100 mGy.

• ”Doses below 100mGy to the developing organism should not be considered a reason for terminating a pregnancy.”

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Non-cancer diseases