Gonzalez Radiation WNU Oxford 2012 Abel... · 2012-11-11 · 1 Radiation Protection 1. Epistemology of Radiation 2. International Paradigms 1. Epistemology of Radiation 2. International

1

Radiation Protection1. Epistemology of Radiation

2. International Paradigms

Radiation Protection1. Epistemology of Radiation

2. International Paradigms

WNU–Summer Institute 2012Christ Church Lecture Hall, University of Oxford, UK; August 2th, 2012

WNU–Summer Institute 2012Christ Church Lecture Hall, University of Oxford, UK; August 2th, 2012

Abel J. GonzálezVice-President of the International Commission on Radiological Protection (ICRP)

Representative to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)Member of the Commission of Safety Standards of the IAEA

Autoridad Regulatoria Nuclear; Av. del Libertador 8250; (C1429BNP) Ciudad de Buenos Aires, Argentina+54 11 6323 1758; (official) [email protected]; (private) [email protected]

Abel J. GonzálezViceVice--President of the International Commission on Radiological ProtecPresident of the International Commission on Radiological Protection (ICRP) tion (ICRP)

Representative to the United Nations Scientific Committee on thRepresentative to the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR)e Effects of Atomic Radiation (UNSCEAR)Member of the Commission of Safety Standards of the IAEAMember of the Commission of Safety Standards of the IAEA

Autoridad Autoridad RegulatoriaRegulatoria NuclearNuclear; ; Av. del Libertador 8250; (Av. del Libertador 8250; (C1429BNP) Ciudad de Buenos AiresC1429BNP) Ciudad de Buenos Aires, , ArgentinaArgentina+54 11 6323 1758; +54 11 6323 1758; (official)(official) [email protected]; [email protected]; (private) [email protected](private) [email protected]

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ContentContentFIRST PARTEpistemology:

Radiation Science and its Limitations Quantification Levels Effects

SECOND PARTProtection Paradigm

The International Radiation Protection System The International Organizations Radiation Protection Recommendations Global Regime

FIRST PARTEpistemology:

Radiation Science and its Limitations Quantification Levels Effects

SECOND PARTProtection Paradigm

The International Radiation Protection System The International Organizations Radiation Protection Recommendations Global Regime

3


Radiation Science and its Limitations


Radiation Science and its Limitations

26 July, 2012 3

44

(1)

Quantification

of Radiation Exposure

(1)

Quantification

of Radiation Exposure

WNU-Summer Institute

5

Radioactivesubstance

(radioactivitymeasured in Becquerels[or curie])

Radioactivesubstance

(radioactivitymeasured in Becquerels[or curie])

Radiation emitted(radiation fluence)Radiation emitted(radiation fluence)

Absorbed dose(incurred due to

radioactivity inside the body

or radiation fluencefrom outside

–measured in gray[or rad])

Absorbed dose(incurred due to

radioactivity inside the body

or radiation fluencefrom outside

–measured in gray[or rad])

Activity，A(bequerel or curie)

Absorbed dose, D(gray or rad)

Fluence，Φ

Absorbed dose, D(gray or rad)

Radiation weighting factor, wR

Equivalent dose, HT(sievert or rem)

Equivalent dose, HT(sievert or rem)

Tissue weighting factor), wT

Effective dose, E(sievert or rem)

99

Absorbed Dose(Gy)

Absorbed Dose(Gy)

wR wTEquivalent Dose (organ)

(Sv)

Equivalent Dose (organ)

(Sv)

ConversionFactor

(Sv Bq-1)

ConversionFactor

(Sv Bq-1)

Conversion Factor

(Sv cm2)

Conversion Factor

(Sv cm2)

EfectiveDose(Sv)

EfectiveDose(Sv)

Activity(Bq)

Activity(Bq)

Fluence(cm-2)

Fluence(cm-2)

(2)

International Estimates of Global

Radiation Exposure Levels

(2)

International Estimates of Global

Radiation Exposure Levels

11

Sources

Natural

Cosmic rays

Terrestrial

Inhalation

[radon]

Natural

Cosmic rays

Terrestrial

Inhalation

[radon]

Artificial

Medical

Military

Nuclear Power

Occupational

Accidents

Artificial

Medical

Military

Nuclear Power

Occupational

Accidents

12

annual dosemSv/year

~100

~ 10

~ 2.4

~ 1

Natural Background

TYPICALLY HIGHTYPICALLY HIGH

AVERAGE AVERAGE

MINIMUM MINIMUM

VERY HIGHVERY HIGHFew peopleIn few areas

Many peopleIn many areas

Majority of peoplearound the world

13OSU, Stillwater, OK, USA, February 2008

14

Source Global average dose Typical range(mSv per year) (mSv per year)

External exposure Cosmic rays 0.4 0.3 to 1.0 Terrestrial gamma rays 0.5 0.3 to 1.0

Internal exposure Inhalation (mainly radon) 1.3 0.2 to 10 Ingestion 0.3 0.2 to 1.0

Total 2.4 1 to 13

Source Global average dose Typical range(mSv per year) (mSv per year)

External exposure Cosmic rays 0.4 0.3 to 1.0 Terrestrial gamma rays 0.5 0.3 to 1.0

Internal exposure Inhalation (mainly radon) 1.3 0.2 to 10 Ingestion 0.3 0.2 to 1.0

Total 2.4 1 to 13

Exposure to natural sources

highest…up to above 100!highest…up to above 100!

Medical sources

16

13081308

332332

2020

482482

Radio-diagnostic proceduresAverage annual frequency per 1000

Radio-diagnostic proceduresAverage annual frequency per 1000

HighHealth-care

HighHealth-care

MediumHealth-care

MediumHealth-care

LowHealth-care

LowHealth-care

Global averageGlobal average

17

1.881.88

0.320.32

0.030.03

0.610.61

HighHealth-care

HighHealth-care

MediumHealth-care

MediumHealth-care

LowHealth-care

LowHealth-care

Global averageGlobal average

Annual average per-caput dose(in mSv)

18

CT scans by year in US (millions

18.3 19.521.0

22.625.1 26.3

30.6

34.9

39.6

45.4

50.1

53.9

57.6

62.0

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

No

. o

f p

roce

du

res

(mill

ion

s)

Annual growth of >10% per yea

Computerized tomography (CT)

Annual growth > 10%/yr

U.S. population < 1%/yr

procedures by year (millions)

20

Military activitiesMilitary activities

21

Nuclear weapons tests

Atmospheric testsUnderground tests

1945100

50

0

50

100

150

NU

MBE

R

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

22

Doses due to atmospheric nuclear testing

0

0.02

0.04

0.06

0.08

0.1

0.12

1945 1955 1965 1975 1985 1995 2005

Year

Annu

al e

ffect

ive

dose

(mSv

)

23

Civil nuclear power

24

Global average levels

Source: UNSCEAR 2000 Report

Nuclear power<0.01%

Chernobyl accident

<0.1%

Weapons fallout<0.2%

Natural sources

80%

Medical examinations

20%

25

Occupational exposures

26

0

1

2

3

4

5

6

Nucle

ar in

dust

ry

Defen

ce

Medici

neCoa

l min

ing

Other

min

ing

Aircre

wOth

er w

orkp

laces

Ann

ual e

ffect

ive

dose

(mSv

)Man-made sources Natural sources

0 10 20 30

Millionsexposed

ArtificialNatural

27

Global annual per caput dose (mSv)

28

Annual per caput dose (mSv) for USA

29

In summary:Patients are

being exposed to increased

radiation levels

In summary:Patients are

being exposed to increased

radiation levels

30

(3)Recent Developments on the epistemology of

Radiation Health Effects(Method, validity and scope of the scientific knowledge

on the detrimental effects of radiation exposure)

(3)Recent Developments on the epistemology of

Radiation Health Effects(Method, validity and scope of the scientific knowledge

on the detrimental effects of radiation exposure)

30WNU-Summer Institute


Chromosomes

DNA

26 July, 2012

3232WNU-Summer Institute26 July, 2012

3326 July, 2012

0.2 meters!

2 nanometers

1400nanometers

Chromosomes

are a

condensed

packing of

DNA

Chromosomes

are a

condensed

packing of

DNA

343426 July, 2012


The The EnciclopedyEnciclopedy of Lifeof LifeBases Bases LettersLetters

CodonsCodons Words Words

IntronsIntrons Interruptions Interruptions

ExonsExons ParagraphsParagraphs

Genes Genes ChaptersChapters

Chromosomes Chromosomes VolumesVolumes

26 July, 2012

36WNU-Summer Institute 36

Radiation harm to DNA

26 July, 2012


Mutation!Mutation!

Many other

mutations occur due

to DNA miscopying,

thermal agitation, etc.

Usually they can be

correctly repaired by

copying the DNA

template.

Many other

mutations occur due

to DNA miscopying,

thermal agitation, etc.

Usually they can be

correctly repaired by

copying the DNA

template.



What is the

problem then?:

the chromosome is

a very complex

packing of DNA

What is the

problem then?:

the chromosome is

a very complex

packing of DNA

nucleosomesnucleosomesnucleosomes

26 July, 2012

42

10 nm

0.5 0.5 MevMev

2nm




Chromosomes deletions

26 July, 2012


Chromosomes Translocations

26 July, 2012


Chromosomal aberrations are easily identifiable in the microscope

Chromosomal aberrations are easily identifiable in the microscope26 July, 2012


radiation hits a cell nucleus!

radiation hits a cell nucleus!

No changeNo change

DNA mutationDNA mutation

26 July, 2012


Probability of mutationProbability of mutation

DoseDose

p = a D + b D2p = a D + b D2

p = a D p = a D

pD (a D + b D2) e-cDpD (a D + b D2) e-cD

26 July, 2012


DNA mutation pD a D

DNA mutation pD a D 3)Cell survives

but mutated

Stochasticeffects

1) Mutation repaired

Deterministic Effects (>~1Sv)

No effects

2) Cell dies

26 July, 2012


Mutation repaired

Viable Cell

First possible outcome:mutation is repaired

26 July, 2012


Unviable Cell

Second possible outcome:cell killing (apoptosis)

26 July, 2012


Cell killingat around 1000mSv deterministic effects:burns, organ failure,

death!

Acute dose

Probability

> ~1000 mSv

100%

26 July, 2012

55

Radiation accidents involving masive cell killing are rare

Since 1944 there were around 400 accidents

worldwide.

Approximately 3000 persons were injured,

with 120 fatalities (including 28 Chernobyl

victims).

Since 1944 there were around 400 accidents

worldwide.

Approximately 3000 persons were injured,

with 120 fatalities (including 28 Chernobyl

victims).

56

57

58

59


Cell survives but mutated

Altered process

Third possible outcome:viable but mutated cell

26 July, 2012


Normal process

26 July, 2012


Altered process

26 July, 2012

WNU-Summer Institute 63

Cell survives but mutated

Stochastic effects

26 July, 2012


Stochastic effects

Cancer

Hereditable

Antenatal

Cancer

Hereditable

Antenatal

26 July, 2012


CancerCancer

26 July, 2012

6666

Prevalent opinion onradiation-induced cancer

Radiation Radiation

mutates DNAmutates DNA

Failure to Failure to

repair DNA repair DNA

Viable cell withViable cell with

carcinogenescarcinogenes

TumourTumour

promotionpromotion

Malignant Malignant

conversion conversion

Metastasis of Metastasis of

malignancymalignancy

26 July, 2012

INMUNE SYSTEMINMUNE SYSTEM

67


Estimates of the Risk of Cancer due to

Radiation Exposure

Estimates of the Risk of Cancer due to

Radiation Exposure

26 July, 2012


Radioepidemiology

(Epidemia (Gk): prevalence of disease)(Epidemia (Gk): prevalence of disease)

26 July, 2012


Control group“N” people“C” cancers“n” probability of ‘natural’ cancer

Control group““NN”” peoplepeople““CC”” cancerscancers““nn”” probability of probability of ‘‘naturalnatural’’ cancercancer

Exposed group“N” people“E” cancers“n” probability of ‘natural’cancer‘pD’ probability of ‘radiation’ cancer

Exposed group““NN”” peoplepeople““EE”” cancerscancers““nn”” probability of probability of ‘‘naturalnatural’’cancercancer‘‘ppDD’’ probability of probability of ‘‘radiationradiation’’ cancercancer

26 July, 2012


E= n N

+ pd D N

Numberof

cancersin

exposedgroup

C=n N

Numberof

cancersin

controlgroup

C=n N

Numberof

cancersin

controlgroup

E-C

Difficult to assess!

26 July, 2012


UNSCEAR has reviewed many many

epidemiological data on effects of radiation in

exposed populations

UNSCEAR has reviewed many many

epidemiological data on effects of radiation in

exposed populations

26 July, 2012


The radium dial painters,…

26 July, 2012


…the early x-rays doctors and patients……the early x-rays doctors and patients…

26 July, 2012


..the Mayak cohort of workers…

MAYAK

26 July, 2012


..the survivors of Hiroshima y Nagasaki....the survivors of Hiroshima y Nagasaki..

26 July, 2012


…all these victims of radiation exposure have

unwillingly contributed to the

UNSCEAR’s epidemiological assessments.

…all these victims of radiation exposure have

unwillingly contributed to the

UNSCEAR’s epidemiological assessments.

26 July, 2012


Slide 6

Cohort of Hiroshima & Nagasaki(LIFE SPAN STUDY, LSS)

Mt.HijiMt.Hiji

26 July, 2012

7979

Solid Cancer Mortality47 years of follow-up (1950-1997)

Exposed population: 9,335 (10,127) cancer deaths

Reference population: 8,895 (9,648) cancer deaths

~440 (479) cancers attributable to radiation (5%)

Exposed population: 9,335 (10,127) cancer deaths

Reference population: 8,895 (9,648) cancer deaths

~440 (479) cancers attributable to radiation (5%)

Preston et al, Radiat Res 160:381-407, 2003(updated figures)Preston et al, Radiat Res 160:381-407, 2003(updated figures)

26 July, 2012


Lifetime cancer mortality risk (after 1000 mSv acute dose)

~ 0.6-1.0%. for leukæmia

and

~4.3–7.2% for all solid cancers combined, (lower for men than for women)

Lifetime cancer mortality risk (after 1000 mSv acute dose)

~ 0.6-1.0%. for leukæmia

and

~4.3–7.2% for all solid cancers combined, (lower for men than for women)

Lifetime cancer risk estimates for those exposed as children might be a factor of 2 to 3 times higher than the estimates for a population exposed at all ages.

Lifetime cancer risk estimates for those exposed as children might be a factor of 2 to 3 times higher than the estimates for a population exposed at all ages.

26 July, 2012

UNSCEAR Estimates of NOMINAL Cancer Risk


Hereditable EffectsHereditable Effects

26 July, 2012


Prevalent opinion on the induction of hereditable effects from radiation exposure

Radiation Radiation

Mutes the DNA Mutes the DNA

of a Germinal of a Germinal

CellCell

Failure to Failure to

RepairRepair

Viable Sperm Viable Sperm

or Ovum or Ovum

Containing Containing

Defective GenesDefective Genes

26 July, 2012


The risk is so low that the estimation has to be based on animal studies

The risk is so low that the estimation has to be based on animal studies

26 July, 2012


Hereditable Effects

Total risk to first generation following parental exposure:

~ 0.2% per Sv

>1/10 the risk of fatal carcinogenesis

constitutes 0.5% of baseline

Total risk to first generation following parental exposure:

~ 0.2% per Sv

>1/10 the risk of fatal carcinogenesis

constitutes 0.5% of baseline

26 July, 2012


Antenatal EffectsAntenatal Effects

26 July, 2012

86WNU-Summer Institute 8626 July, 2012


1000mSv1000mSv

26 July, 2012

= IQ= IQ


Shift in the IQ curve:30 IQ units per 1000 mSv incurred during the 8-15 weeks

1000mSv1000mSv

26 July, 2012

= IQ= IQ

89

Latest newsLatest news

91

93

Summary

of the scientific knowledge

Summary

of the scientific knowledge

94

Dose (Sv)

Likelihoodof health effects

100%(certainty)

~0,1

Approx. lower bound

of pathological knowledge

~ 5%(UNSCEAR estimate)

~1 ~10

Tissue reactionsClinical diagnosis

(individual pathology)

Approx. lower bound of epidemiological

knowledge

Cytogenetic exposure indicators

radiation

syndromes

and death

~ 10%

~ 1%

General radiobiological information

Increase incidence of malignanciesStatistical estimates (epidemiology of populations)

Frequentist(Bernoullian)estimation

Frequentist(Bernoullian)estimation

Subjective(Bayesian)

estimation

Subjective(Bayesian)

estimation

Estimated likelihood of cancer


95

Dose (Sv)


100%(certainty)

~0,1

Approx. lower bound



~1 ~10


knowledge

Increased

syndromes

and death

~ 10%

~ 1%

TypicalB

ackground



Region of individualattribution of effects

Region of inference of radiation risks

Region of collective attribution of effects

96

Dose (Gy)


100%(certainty)

~0,1

Approx. lower bound



~1 ~10


knowledge

Increased

syndromes

and death

~ 10%

~ 1%

TypicalB

ackground



Region of individualattribution of effects

Region of inference of radiation risks

Region of collective attribution of effects

97

Totalbackground incidence of effects

Background annual dose

(average 2.4, typical 10 mSv y-1)

Postulated likelihood of health effects

Dose

Radiation-unrelatedbackground

incidence

Presumedradiation-related

background incidence

Nominal incrementallikelihoodof health effects

Incremental dose

0.005%/mSv0.005%/mSv


Take away pointsTake away points

26 July, 2012

Activity bequerel

Dose sievert (1 Sv = 1000 milliSieverts)

(mSv)

Background 2.4 mSv/y (up to above 100 mSv)

Medical

Nuclear

Activity Activity bequerelbequerel

Dose Dose sievertsievert (1 (1 SvSv = 1000 = 1000 milliSievertsmilliSieverts) )

((mSvmSv))

Background Background 2.4 2.4 mSv/ymSv/y ((up to above 100 up to above 100 mSvmSv))

Medical Medical

Nuclear Nuclear

26 July, 2012 WNU-Summer Institute 99

100

Probable observable increase in the incidence of cancer, if the exposed group is more than a few hundred

people

Nausea, vomiting possible, mild bone marrow

depression;subsequent additional

cancer risk of about 10%

Moderate dose:towards

1000 mSv (acute whole body dose)

Observable increase in theincidence of cancer

Certain nausea, likely bone marrow syndrome; high risk

of death from about 4000 mSv (without medical treatment).

Significant additional cancer risk!

High dose:above 1000 mSv (acute

whole body dose)

Possible observable increase in the incidence of cancer, if the exposed group is very

large (e.g., >100,000 people)

No acute effects; subsequent additional

cancer risk of less than 1%

Low dose:towards 100 mSv

No observable increase in the incidence of cancer, even

in a large exposed group

No acute effects;extremely small additional

cancer risk

Very low dose:about 10 mSv or less

Consequences for an exposed population

Effects on individualsDose


… above the prevalent background dose,

an increment in dose

is assumed to result (for rad. prot. purposes)

in a proportional increment

in the probability of stochastic effects of

0.005% per mSv

… above the prevalent background dose,

an increment in dose

is assumed to result (for rad. prot. purposes)

in a proportional increment

in the probability of stochastic effects of

0.005% per mSv

26 July, 2012

102

Remember!

1. Radiation exposure at high acute levels, e.g. above several thousand of millisievertsis very dangerous.

2. Radiation exposure at low chronic levels, e.g. towards tens of millisieverts per year, presents an extremely low risk.

3. Radiation exposure at very low chronic levels, e.g. < 1 millisievert per year, is not an individual health issue.

1. Radiation exposure at high acute levels, e.g. above several thousand of millisievertsis very dangerous.

2. Radiation exposure at low chronic levels, e.g. towards tens of millisieverts per year, presents an extremely low risk.

3. Radiation exposure at very low chronic levels, e.g. < 1 millisievert per year, is not an individual health issue.

26 July, 2012 WNU-Summer Institute 102

103103WNU, ,

[email protected]@arn.gob.ar

+541163231758

Av. del Libertador 8250Buenos Aires

Argentina

Thank you!Thank you!

26 July, 2012

104

Additional information to the FIRST PART

Additional information to the FIRST PART

26 July, 2012 104


The Health Effectsof Radiation

A close book?A close book?

26 July, 2012


10-15s. 10-9s. 10-3s. 10 2 m. 100 years

PhysicsPhysicsandand

chemistrychemistryEpidemioEpidemio--

logylogyBiologyBiology

Time

ExposureExposureManifestationManifestation

ofof

effectseffects

Physiology?

The time scale of the phenomena limits knowledge.The time scale of the phenomena limits knowledge.26 July, 2012



New UNSCEAR’s assessments

Epidemiological evaluation of cardiovascular disease

Non-targeted and delayed effects of radiation exposure

Effects of ionizing radiation on the immune system

Epidemiological evaluation of cardiovascular disease

Non-targeted and delayed effects of radiation exposure

Effects of ionizing radiation on the immune system

26 July, 2012


Cardiovascular diseasesCardiovascular diseases

26 July, 2012


Chernobyl workers,

atomic bomb survivors, and

radiotherapy patients …

… seem to suffer a higher risk of

cardiovascular diseases.26 July, 2012


‘Non-targeted’and

delayed effectsof radiation exposure

‘Non-targeted’and

delayed effectsof radiation exposure

26 July, 2012


Adaptive Response

+

Mutation

Mutations

Mutations

26 July, 2012


Adaptive responseconditioningconditioning

dosedose responseresponse

challengingchallengingdosedose

responseresponse

conditioningconditioningdosedose

challengingchallengingdosedose

responseresponse++

26 July, 2012


The role of apoptosis(cell killing by mutations)

If at low doses, apoptosis >> carcinogenesis...

..then.. hormesis!

If at low doses, If at low doses, apoptosis >> carcinogenesis......

..then.. ..then.. hormesishormesis!!

26 July, 2012

115115115WNU-Summer InstituteWNU-Summer Institute

ApoptosisApoptosis

Dose rateDose rate

Mutation RateMutation Rate

ApoptosisApoptosis

CarcinogenesisCarcinogenesis

hormesishormesis

26 July, 201226 July, 2012


Genomic instability …Genomic instability …

… or … increased rate of acquisition of

alterations in the genome.

… or … increased rate of acquisition of

alterations in the genome.

26 July, 2012

Basic paradigms of radiobiology

Effects occur in cells whosenucleus crossed by radiation

Damage fixed in DNA of irradiated cell, if not lethal, transmitted to descendant

MicronucleusMicronucleus

Mitotic failure: aneuploid

Mitotic failure: aneuploid

MutationMutation Chromosomalaberration

Chromosomalaberration

Cellular death

Cellular death

Challenge to the paradigm

Genomic instabilityGenomic instability


120120

Bystander effects

The so-called “bystander” effect is the ability of irradiated

cells to convey damage to neighbouring cells

not directly irradiated.

The so-called “bystander” effect is the ability of irradiated

cells to convey damage to neighbouring cells

not directly irradiated.

26 July, 2012

121121

“Bystander” effect

26 July, 2012

122

Signals via intercellular unions(Azamm 2001)

Signals via intercellular unions(Azamm 2001)

Signals via medium/plasmaSignals via medium/plasma

ROSNitric oxideCytokinesTGF

(Lehnert 1997)

ROSNitric oxideCytokinesTGF

(Lehnert 1997)

26 July, 2012


Clastogenic plasma factors

There is a large body of evidence that blood plasma from

irradiated animals and humans can contain so-called

“clastogenic plasma factors” capable of inducing

chromosomal damage in unexposed cells.

There is a large body of evidence that blood plasma from

irradiated animals and humans can contain so-called

“clastogenic plasma factors” capable of inducing

chromosomal damage in unexposed cells.

26 July, 2012



Abscopal effects

An abscopal effect is said to occur if there is a significant

response in a tissue that is physically separate from the

region of the body exposed to radiation.

An abscopal effect is said to occur if there is a significant

response in a tissue that is physically separate from the

region of the body exposed to radiation.

Human & Experimental Toxicology, Volume 23, Issue 2, 1 February 2004, ArnoldHuman & Experimental Toxicology, Volume 23, Issue 2, 1 February 2004, Arnold

26 July, 2012


Irradiation ofan organ

Irradiation ofan organ

Effects in another organ

26 July, 2012


Effects of ionizing radiation on the

immune system

Effects of ionizing radiation on the

immune system

26 July, 2012


Infections

Cancer

Immune

system

Does radiation exposure affect the immune system?

26 July, 2012

129

SECOND PART

Protection Paradigm:

The International Radiation Protection System

SECOND PART

Protection Paradigm:

The International Radiation Protection System

26 July, 2012 129

13026 July, 2012 130

(1)

The International Organizations

(1)

The International Organizations


13126 July, 2012 131

Epistemology of radiationMethod, validity and scope of the scientific

knowledge on radiation

Radiation Protection ParadigmConceptual model for keeping people protected

Global Radiation Safety RegimeEstablishing international safety standards and

providing for their global application

13226 July, 2012 132

UNSCEARUNSCEAR


133133

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

Established by the UN General Assembly in 1955 Assess levels & effects of ionizing radiation Reports findings to Assembly Scientists from 21 UN Member States Other States provide relevant data Holds annual sessions in Vienna UNEP arranges secretariat and provides support

Established by the UN General Assembly in 1955 Assess levels & effects of ionizing radiation Reports findings to Assembly Scientists from 21 UN Member States Other States provide relevant data Holds annual sessions in Vienna UNEP arranges secretariat and provides support

134134

Member States on UNSCEAR

Argentina Brazil Mexico Peru Australia China India Indonesia Japan Korea Pakistan Canada USA

Argentina Brazil Mexico Peru Australia China India Indonesia Japan Korea Pakistan Canada USA

Egypt Sudan Belgium Belarus Finland France Germany Poland Russia Slovakia Spain Sweden UK Ukraine

Egypt Sudan Belgium Belarus Finland France Germany Poland Russia Slovakia Spain Sweden UK Ukraine

135

WNU-Summer InstituteWNU-Summer Institute 135135

The latest UNSCEAR reportsThe latest UNSCEAR reports

SourcesSources EfectsEfects HereditableHereditable

26 July, 201226 July, 2012

UNSCEAR 2000 Report (sources): http://www.unscear.org/unscear/en/publications/2000_1.html

UNSCEAR 2000 Report (effects): http://www.unscear.org/unscear/en/publications/2000_2.html

UNSCEAR 2001Report (hereditary): http://www.unscear.org/unscear/en/publications/2001.html

UNSCEAR 2006 Report (new): http://www.unscear.org/unscear/en/publications/2006_1.html

UNSCEAR 2000 Report (sources): http://www.unscear.org/unscear/en/publications/2000_1.html

UNSCEAR 2000 Report (effects): http://www.unscear.org/unscear/en/publications/2000_2.html

UNSCEAR 2001Report (hereditary): http://www.unscear.org/unscear/en/publications/2001.html

UNSCEAR 2006 Report (new): http://www.unscear.org/unscear/en/publications/2006_1.html

NewNew

13726 July, 2012 137

ICRPICRP


13826 July, 2012 138

The International Commission on Radiological Protection (ICRP)


Registered charity established to advance

radiological protection for the public benefit

by providing recommendations and guidance.

Registered charity established to advance

radiological protection for the public benefit

by providing recommendations and guidance.

139

First ICRP meeting 1928First ICRP meeting 1928

140

141

14226 July, 2012 142

IAEAIAEA


14326 July, 2012 143

The International Atomic Energy Agency (IAEA)


14426 July, 2012 144

The IAEA is the only organ within the UN system with specific statutory responsibilities

on radiation protection and safety


on radiation protection and safetyWNU-Summer Institute

14526 July, 2012 145

to establishstandards


to provide for their applicationto provide for

their application

to service international conventionsto service international conventions

IAEAstatutory safety functions


146

IAEA Safety Standardshttp://www-ns.iaea.org/standards/

IAEA Safety Standardshttp://www-ns.iaea.org/standards/

147

International Labour Organisation

148

Radiation Protection Convention No. 115(1960) Date of entry into force: 17.6.1962

48 ratifications Argentina 15.6.1978 Azerbaijan 19.5.1992 Barbados 8.5.1967 Belarus 26.2.1968 Belgium2.7.1965 Beliz 15.12.1983 Brazil 5.9.1966 Chile 14.10.1994 Czech Rep. 1.1.1993 Denmark 7.2.1974 Djibouti 3.8.1978 Ecuador 9.3.1970 Egypt 18.3.1964 Finland 16.10.1978 France 18.11.1971 Germany 26.9.1973

Argentina 15.6.1978 Azerbaijan 19.5.1992 Barbados 8.5.1967 Belarus 26.2.1968 Belgium2.7.1965 Beliz 15.12.1983 Brazil 5.9.1966 Chile 14.10.1994 Czech Rep. 1.1.1993 Denmark 7.2.1974 Djibouti 3.8.1978 Ecuador 9.3.1970 Egypt 18.3.1964 Finland 16.10.1978 France 18.11.1971 Germany 26.9.1973

Ghana 7.11.1961 Greece 4.6.1982 Guinea 12.12.1966 Guyana 8.6.1966 Hungary 8.6.1968 India 17.11.1975 Iraq 26.10.1962 Italy 5.5.1971 Japan 31.7.1973 Kyrgyzstan 31.3.1992 Latvia 8.3.1993 Lebanon 6.12.1977 Luxembourg 8.4.2008 Mexico 19.10.1983 Netherlands 29.11.1966 Nicaragua 1.10.1981

Ghana 7.11.1961 Greece 4.6.1982 Guinea 12.12.1966 Guyana 8.6.1966 Hungary 8.6.1968 India 17.11.1975 Iraq 26.10.1962 Italy 5.5.1971 Japan 31.7.1973 Kyrgyzstan 31.3.1992 Latvia 8.3.1993 Lebanon 6.12.1977 Luxembourg 8.4.2008 Mexico 19.10.1983 Netherlands 29.11.1966 Nicaragua 1.10.1981

Norway 17.6.1961 Paraguay 10.7.1967 Poland 23.12.1964 Portugal 17.3.1994 Russian Fed. 22.9.1967 Slovakia 1.1.1993 Spain 17.7.1962 Sri Lanka 18.6.1986 Sweden 12.4.1961 Switzerland 29.5.1963 Syrian A. R. 15.1.1964 Tajikistan 26.11.1993 Turkey 15.11.1968 Ukraine 19.6.1968 U.K. 9.3.1962 Uruguay 22.9.1992

Norway 17.6.1961 Paraguay 10.7.1967 Poland 23.12.1964 Portugal 17.3.1994 Russian Fed. 22.9.1967 Slovakia 1.1.1993 Spain 17.7.1962 Sri Lanka 18.6.1986 Sweden 12.4.1961 Switzerland 29.5.1963 Syrian A. R. 15.1.1964 Tajikistan 26.11.1993 Turkey 15.11.1968 Ukraine 19.6.1968 U.K. 9.3.1962 Uruguay 22.9.1992

149

(2)The International Radiation

Protection Recommendations

The conceptual model for keeping people safe from radiation exposure

(2)The International Radiation

Protection Recommendations

The conceptual model for keeping people safe from radiation exposure

26 July, 2012 149

150

In paradigm choice there is no standard higher

than the assent of the relevant community

Thomas S. Kuhn, The Structure of Scientific Revolutions, p. 93 (1960).

In paradigm choice there is no standard higher

than the assent of the relevant community

Thomas S. Kuhn, The Structure of Scientific Revolutions, p. 93 (1960).

151

Totalbackground incidence of effects

Background annual dose

(average 2.4, typical 10 mSv y-1)

Postulated likelihood of health effects

Dose

Radiation-unrelatedbackground

incidence

Presumedradiation-related

background incidence

Nominal incrementallikelihoodof health effects

Incremental dose

0.005%/mSv0.005%/mSv

152

ICRP had to introduce the concept of

‘detriment-adjusted’

‘nominal’ risk coefficients

ICRP had to introduce the concept of

‘detriment-adjusted’

‘nominal’ risk coefficients

153

Detriment-adjusted Nominal Risk Coefficients

Risk Coefficient: A numeral, expressed in % Sv-1, which –multiplied by dose– quantifies the plausibility of harm.

Nominal: The stated numeral does not necessarily correspond to its real value: it relates to hypothetical (no real) people who are averaged over age and sex.

Detriment-adjusted: The numeral is multidimensional, expressing plausible expectation of harm, and includinginter alia the weighted plausibility of fatal and non-fatal harm, and life-lost should the harm actually occur.

Risk Coefficient: A numeral, expressed in % Sv-1, which –multiplied by dose– quantifies the plausibility of harm.

Nominal: The stated numeral does not necessarily correspond to its real value: it relates to hypothetical (no real) people who are averaged over age and sex.

Detriment-adjusted: The numeral is multidimensional, expressing plausible expectation of harm, and includinginter alia the weighted plausibility of fatal and non-fatal harm, and life-lost should the harm actually occur.

154

4.20.14.1Adult

5.70.25.5Whole

TotalHereditableCancer &

leukæmia

Nominal Population

Detriment-adjusted nominal risk coefficients[% Sv-1]

Rounded value used in RP standards~5%Sv-1Rounded value used in RP standards~5%Sv-1

155

Protection basic dogma

Time

Shielding

Distance

……..but…..it depend on the situation!

Time

Shielding

Distance

……..but…..it depend on the situation!

156

Time?

?

?

The principles of

radiological protection

The principles of

radiological protection

The principles of radiological protectionThe principles of radiological protection

• The Principle of Justification

• The Principle of Optimization of Protection

• The Principle of Dose Limits

• The Principle of Protection of Future

Generations and the Environment

• The Principle of Justification

• The Principle of Optimization of Protection

• The Principle of Dose Limits

• The Principle of Protection of Future

Generations and the Environment

The Principle of JustificationThe Principle of Justification

• Any decision that alters the radiation exposure

situation should do more good than harm.

• Any decision that alters the radiation exposure

situation should do more good than harm.

Justification

Good > bad

Electricity) (good)

Is the installation justied?good > bad?

radioactive discharges(bad)

Was evacuation justified?Was evacuation justified?

Justification!

The Principle of Optimization of ProtectionThe Principle of Optimization of Protection

• Best protection under the

prevailing circumstances (The likelihood of incurring exposure, the number of

people exposed, and the magnitude of their individual

doses should all be kept as low as reasonably achievable,

taking into account economic and societal factors.)

• Best protection under the

prevailing circumstances (The likelihood of incurring exposure, the number of

people exposed, and the magnitude of their individual

doses should all be kept as low as reasonably achievable,

taking into account economic and societal factors.)

167

DetrimentSocial cost

Detriment +Social cost

RP levelRP levelOptimalOptimal

The Principle of Dose LimitationThe Principle of Dose Limitation

• The total dose to any individual should not

exceed appropriate limits, constraints or

reference levels.

• The total dose to any individual should not

exceed appropriate limits, constraints or

reference levels.

26 July, 2012 169

Naturalbackground

radiation

ExpectedExpectedadditional additional

dose dose

Activity introducedActivity introduced

RestrictionsRestrictions: dose limits and constraints: dose limits and constraints

17026 July, 2012 170Wastes

Hospitals

IndustryTransport

Mining

Nuclear power

Industry

Dose limit

17126 July, 2012 171

Source constraint

172

26 July, 2012

172

Averteble

dose

Averteble

dose

Referencelevel

Extant

dose


173

The principle of protection of future generations and the environment

The principle of protection of future generations and the environment

Future generations must be protected against radiation.

The environment must also be protected in order to:

maintain biological diversity,

ensure the conservation of species, and

protect the health and status of natural habitats, communities,

and ecosystems

Future generations must be protected against radiation.

The environment must also be protected in order to:

maintain biological diversity,

ensure the conservation of species, and

protect the health and status of natural habitats, communities,

and ecosystems

How to protect the future?How to protect the future?

17526 July, 2012 175

Doses after 1 year of operation

D

t1st year 2ndyear 3rd year …. … …. nth year

17626 July, 2012 176

Doses after 2 years of operation

D


2ndyear3rdyear

4thyear …. … ….

17726 July, 2012 177

Doses after 3 years of operation

D


2ndyear3rdyear

4thyear …. … ….

3rd year

4th year5th year

….…

178

CONTROL

EQUILIBRIUM: BUILDEQUILIBRIUM: BUILD--UPUP

Types of exposure situationsTypes of exposure situations

Types of exposure situationsTypes of exposure situations

• Planned exposure situations

• Emergency exposure situations

• Existing exposure situations

• Planned exposure situations

• Emergency exposure situations

• Existing exposure situations

Planned exposure situations,Planned exposure situations,

are situations involving the planned

introduction and operation of sources.

(…previously categorised as practices.)

are situations involving the planned

introduction and operation of sources.

(…previously categorised as practices.)

18226 July, 2012 182

Natural background

Effective Effective dosedose

PracticePractice

Regulatory controlRegulatory control

Planned exposure situationPlanned exposure situation

Emergency exposure situations,Emergency exposure situations,

• are unexpected situations such as those

that may occur during the operation of a

planned situation, or from a malicious act.

• are unexpected situations such as those

that may occur during the operation of a

planned situation, or from a malicious act.

Existing exposure situations,Existing exposure situations,

• are exposure situations that already exist

when a decision on control has to be taken,

such as those caused by natural background

radiation.

• are exposure situations that already exist

when a decision on control has to be taken,

such as those caused by natural background

radiation.

18526 July, 2012 185

Avertable

dose

Avertable

dose

Regulatory ambition

Extant

dose

Emergency exposure situations

2009 WNU-Summer Institute

Existing exposure situations

Existing exposure situations

18626 July, 2012 186

3 systemshomogeneous, coherent and consistent….but distinct

Patients

Occupational

Public

Patients

Occupational

Public


18726 July, 2012 187

Source constraint

Doses to be constrained arethose committed in a year

rather than those incurred in a year!



18826 July, 2012 188

Patients(The exposure is voluntary, beneficial for the individual exposed and measurable)(The exposure is voluntary, beneficial for the individual exposed and measurable)

• Radiodiagnosis

• Radiotherapy

• Radiodiagnosis

• Radiotherapy


189

Doses in mSvDoses in mSv

100 100

~~ 10 10

~~ 11


TYPICALTYPICAL

MINIMALMINIMAL

HIGHHIGHFluoroscopFluoroscopyy

Vertebral Vertebral

TTooraxrax

Guidance for the Guidance for the protection of protection of patients in patients in

radioradio--diagnosisdiagnosis

190

TRAINING..!!TRAINING..!!

19326 July, 2012 193

Occupational exposure:

ALL exposure of workers incurred in the course of

their work.

Occupational exposure:

ALL exposure of exposure of workers incurred workers incurred in the course of in the course of

their work.their work.

Workers(voluntary and individually monitored exposure)

Monitored workerMonitored worker


19426 July, 2012 194

Maximum Maximum (except life saving)(except life saving)

mSv in a year

1000

500

100

50

20

OccupationalDose

Restrictions

OccupationalDose

Restrictions

OptimizationOptimizationofof

ProtectionProtection

Annual dose limitAnnual dose limit

Average dose limitAverage dose limit

EEvery effort novery effort nott to to exceedexceed itit

RREESSCCUUEE

All reasonable All reasonable efforteffortssnonot to t to exceedexceed itit

NNOORRMMAALL

19526 July, 2012 195

The female worker:

protecting the

unborn and

the infant

The female worker:

protecting the

unborn and

the infantWNU-Summer Institute

19626 July, 2012 196

Members of the Public(involuntary no-individually monitored exposure)

19726 July, 2012 197

Members of the Public(involuntary no-individually monitored exposure)

Planned exposure situations

(Practices) restrict

the expectedadditional doses

belowindividual dose limitsand source constraints

Planned exposure situations

(Practices) restrict

the expectedadditional doses

belowindividual dose limitsand source constraints

Existing & emergency exposure situations

(Interventions) reducethe extant

avertable dosesbelow

reference levels

Existing & emergency exposure situations

(Interventions) reducethe extant

avertable dosesbelow

reference levels

(planned)‘Practices’

(planned)‘Practices’

19926 July, 2012 199

Naturalbackground

radiation

ExpectedExpectedadditional additional

dose dose

Activity introducedActivity introduced

(planned) ‘Practices’

RestrictionsRestrictions: dose limits and constraints: dose limits and constraints

20026 July, 2012 200Wastes

Hospitals

IndustryTransport

Mining

Nuclear power

Industry

Dose limit

20126 July, 2012 201

Source constraint






202

mSv in a year

1

0.01

1

0.01

Restrictions on the dose

attributable to practices

(additional annual dose)

Restrictions on the dose

attributable to practices

(additional annual dose)

Optimization of protection

Optimization of protection

Source constraintSource constraint

Regulatory limitRegulatory limit

Regulatory exemptionRegulatory exemptionWNU-Summer Institute

203

‘Interventions’(in existing and emergency situations)


20426 July, 2012 204

AvertableDose

Howmuch?

AvertableDose

HowHowmuch?much?

Referencelevel

Extant Dose

Should Should it be it be

reduced?reduced?



205

INTERVENTIONINTERVENTIONALMOST ALWAYS ALMOST ALWAYS

JUSTIFIABLE JUSTIFIABLE

mSv in a year100

10

1

CRITERIA FOR INTERVENING (Extant Annual Dose)

CRITERIA FOR INTERVENING (Extant Annual Dose)

INTERVENTIONINTERVENTIONIS NOT LIKELY TO BE IS NOT LIKELY TO BE

JUSTIFIABLEJUSTIFIABLE

INTERVENTIONINTERVENTIONMAY BEMAY BE

JUSTIFIABLEJUSTIFIABLE


206

Simplified summary of dose

restrictionsand reference

levels(in mSv in a year)

Simplified summary of dose

restrictionsand reference

levels(in mSv in a year)

NO INDIVIDUAL/SOCIETAL BENEFIT ABOVE THIS Emergency workers Emergency workers Evacuation/relocation in emergenciesEvacuation/relocation in emergencies High levels of existing controllable exposuresHigh levels of existing controllable exposures Information, training, monitoringInformation, training, monitoring

DIRECT OR INDIRECT BENEFIT TO THE INDIVIDUALOccupational exposureSheltering, stable iodine, in emergenciesExisting exposures such as radon Comforters and carers to patients Information, training, monitoring or assessment

SOCIETAL, BUT NO INDIVIDUAL DIRECT BENEFITNormal situations No information or training, No individual dose assessment

Exclusion, exemption, clearance

100100

2020

11

0.010.01

207

The use of a reference

level in an existing

exposure situation and

the evolution of the

distribution of

individual doses with

time as a result of the

optimization process

The use of a reference

level in an existing

exposure situation and

the evolution of the

distribution of

individual doses with

time as a result of the

optimization process

20826 July, 2012 208

In paradigm choice there is no standard higher than the assent of the relevant community

DecisionDecision--aiding Processaiding Processbased on radiation protection consideration

DecisionDecision--making Processmaking Process

involving relevant ‘stakeholders’

searching for their informed consent

209

(4)

The International

Regime

(4)

The International

Regime

26 July, 2012 209WNU-Summer Institute

21026 July, 2012 210


on radiation protection and safety


on radiation protection and safetyWNU-Summer Institute

21126 July, 2012 211

“For their efforts

[i] to prevent nuclear energy from being used for military purposes and

[ii] to ensure that nuclear energy for peaceful purposes is

used in the safest possible way“

“For their efforts

[i] to prevent nuclear energy from being used for military purposes and

[ii] to ensure that nuclear energy for peaceful purposes is

used in the safest possible way“

The Nobel Peace Prize2005

TheThe NobelNobel PeacePeace PrizePrize20052005


21226 July, 2012 212



to provide for their applicationto provide for

their application

to service international conventionsto service international conventions




213

Legally Binding

ConventionsLegally Binding

Conventions

214

Convention on Early Notification of a Nuclear Accident

215

Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency

216

Convention on Nuclear Safety

217

Joint Convention on the Safety of Spent Fuel Management and on the

Safety of Radioactive Waste Management

218

Convention on Physical Protection of Nuclear Material

21926 July, 2012 219

International

Radiation Safety

Standards

International

Radiation Safety

Standards


22026 July, 2012 220

Commissionon Safety Standards

(CSS)

Nuclear Safety StandardsCommittee(NUSSC)

Radiation Safety StandardsCommittee(RASSC)

Waste Safety StandardsCommittee(WASSC)

Transport Safety StandardsCommittee(TRANSSC)

Expert Groups Expert Groups Expert Groups Expert Groups

IAEA Board of Governors

22126 July, 2012 221

Long experience

1962: first

international

standards.

Long experience

1962: first

international

standards.

22226 July, 2012 222

A large corpus of

International

Safety Standards

is available

A large corpus of

International

Safety Standards

is available

22326 July, 2012 223

Safety Standards Hierarchy

Safety GuidesSafety Guides

Safety RequirementsSafety Requirements

Safety FundamentalsSafety Fundamentals


http://www-pub.iaea.org/MTCD/publications/PDF/Pub1273c_web.pdf

225

Safety Principles 1: Responsibility for safety 2: Role of government 3: Leadership and management for safety 4: Justification of facilities and activities 5: Optimization of protection 6: Limitation of risks to individuals 7: Protection of present and future generations 8: Prevention of accidents 9: Emergency preparedness and response 10: Protective actions to reduce existing or

unregulated radiation risks

1: Responsibility for safety 2: Role of government 3: Leadership and management for safety 4: Justification of facilities and activities 5: Optimization of protection 6: Limitation of risks to individuals 7: Protection of present and future generations 8: Prevention of accidents 9: Emergency preparedness and response 10: Protective actions to reduce existing or

unregulated radiation risks

26 July, 2012 227

22826 July, 2012 228

rendering APPRAISAL SERVICES

coordinating RESEARCH & DEVELOPMENT

fostering INFORMATION EXCHANGE

providing TECHNICAL ASSISTANCE

Provisionsfor the

application of the

standards:IAEA

mechanisms

promoting EDUCATION & TRAINING

22926 July, 2012 229

Example on how the system for

establishing standards works:Example on how the system for

establishing standards works:

The Regulations for Safe TransportThe Regulations for Safe Transport



23126 July, 2012 231

to Geneva


232

233

234

235

236

237

238

Take away points

1. Additional doses to members of the public should not exceed 1 millisievert in a year

2. Total doses to workers should not exceed 20 millisievert in a year, except for emergency workers () and pregnant workers ()

3. Existing doses to members of the public of several tens of millisieverts, e.g. following an accident, will justify intervention with special protective measures, but if the doses are around 1 millisievert intervention may not be justifiable.

1.1. Additional doses to members of the public Additional doses to members of the public should not exceed should not exceed 1 millisievert in a year

2.2. Total doses to workers should not exceed Total doses to workers should not exceed 20 millisievert in a year, except for , except for emergency workers (emergency workers () and pregnant workers () and pregnant workers ())

3.3. Existing doses to members of the public of Existing doses to members of the public of several tens of millisieverts, e.g. following an , e.g. following an accident, will justify intervention with special accident, will justify intervention with special protective measures, but if the doses are around protective measures, but if the doses are around 1 1 millisievertmillisievert intervention may not be justifiable.intervention may not be justifiable.

26 July, 2012 WNU-Summer Institute

239

Take away points

1. There is a growing international safety regime

2. Obey the international conventions

3. Comply with the international requirements

4. Follow the international guides

5. Use the IAEA application mechanisms

1.1. There is a growing international safety regimeThere is a growing international safety regime

2.2. Obey the international conventionsObey the international conventions

3.3. Comply with the international requirementsComply with the international requirements

4.4. Follow the international guidesFollow the international guides

5.5. Use the IAEA application mechanismsUse the IAEA application mechanisms

26 July, 2012 WNU-Summer Institute239

Download into your computer

the file

González_Reading Material

Download into your computer

the file

González_Reading Material

241WNU, ,


+541163231758


Argentina


26 July, 2012

242

Additional information to the SECOND PART

Additional information to the SECOND PART

26 July, 2012 242

243

Epilogue

Policy Implications:

plausibility of effects at low dosesversus

their attributability

Policy Implications:Policy Implications:



26 July, 2012 243WNU-Summer InstituteS

Policy Implications on effects at low doses :The effects are

probable and, therefore,plausible

but, they are notprovable!

Policy Implications Policy Implications on effects at low doses ::The effects areThe effects are

probable and, therefore,plausible

but, they are notprovable!

26 July, 2012 244S

Low-dose effects cannot be attributed

to radiation exposure!

Low-dose effects cannot be attributed

to radiation exposure!

245WNU, , 2008

Dose (mSv)

Likelihood of Health Effect

Certainty(100%)

epidemiology pathology

Limit of epidemiology


Limit ofpathologyLimit of

pathology

26 July, 2012

246WNU, , 2008

Dose (mSv)

Certainty(100%)

Epidemiology Pathology

PlausiblePlausible Collective estimate

Collective estimate

Individual diagnosisIndividual diagnosis

26 July, 2012


247

Dose (mSv)

Certainty(100%)

Epidemiology Pathology

No attribution

No attribution

Collective attributionCollective attribution

Individual attributionIndividual attribution

26 July, 2012


248

Dealing with uncertainties

Is it plausible that there is a risk at low doses?

Dealing with uncertainties

Is it plausible that there is a risk at low doses?

PlausibilityApparently reasonable or probable,

without necessarily being so.from L. plausibilis, from plaus-, plaudere ‘applaud’.

PlausibilityApparently reasonable or probable,

without necessarily being so.from L. plausibilis, from plaus-, plaudere ‘applaud’.



ICRP Publication 99

Low - Dose Extrapolation

of Radiation Related

Cancer Risk

2006

ICRP Publication 99

Low - Dose Extrapolation

of Radiation Related

Cancer Risk

2006

26 July, 2012

Charles E Land; Uncertainty, lowCharles E Land; Uncertainty, low--dose extrapolation and the threshold hypothesis; dose extrapolation and the threshold hypothesis; J. J. RadiolRadiol. Prot. . Prot. 22 22 (2002) 1(2002) 1––77

250WNU-Summer Institute250

Nominal statistical uncertainty distribution for excess lifetimerisk of solid cancer mortality among atomic-bomb survivors

Confidence limits 7.5–12.5% Sv-1

26 July, 2012


Uncertainty distribution for excess lifetime risk(taking into account extrapolation to another population)

confidence limits 1.2–8.8% Sv-1

approximately approximately loglog--normal normal

15 M a y , 2004 IR P A11: S ie vert L ecture 134

1 .0 -

0 .8 -

0 .6 -

0 .4 -

0 .2 -

‘2

‘4

‘6

‘8

‘10

‘12

‘14

R isk (% )/S v

C u m u la tivep ro b ab ility

95 % u p per lim it

5%

26 July, 2012


1.0-

0.8-

0.6-

0.4-

0.2-

‘2

‘4

‘6

‘8

‘10

‘12

‘14

Risk (%)/Sv

Cumulativeprobability

95% upper limit

5%

Assuming a 20%

probability of threshold8.8%/Sv

26 July, 2012


1.0-

0.8-

0.6-

0.4-

0.2-

‘2

‘4

‘6

‘8

‘10

‘12

‘14

Risk (%)/Sv


95% upper limit

5%

Assuming a 50%

probability of threshold

7%/Sv

8.8%/Sv

26 July, 2012


1.0-

0.8-

0.6-

0.4-

0.2-

‘2

‘4

‘6

‘8

‘10

‘12

‘14

Risk (%)/Sv


95% upper limit

5%

Assuming a 80%

probability of threshold

5%/Sv

8.8%/Sv

26 July, 2012


… Namely …

…ICRP considers that due to the

uncertainties in the radiation risk estimates,

it should presume a nominal radiation risk at low

doses and recommends to limit such nominal risk

with radiation protection measures.

…ICRP considers that due to the

uncertainties in the radiation risk estimates,uncertainties in the radiation risk estimates,

it should presume a nominal radiation risk at low

doses and recommends to limit such nominal risk

with radiation protection measures.26 July, 2012

Policy Implications:



Policy Implications:Policy Implications:



26 July, 2012 256WNU-Summer InstituteS


Likelihood of radiation health effects

Doses Doses

Likelihood

Certainty(100%)

0.005%/mSv for cancer0.0002%/mSv for hereditable

0.005%/mSv for cancer0.0002%/mSv for hereditable

Uncertainty!Uncertainty!

26 July, 2012

258

AttributabilityAttributability

Attribute: regard something as being caused by.

from L. attribut- ‘allotted’: both from attribuere, from ad- ‘to’ + tribuere

‘assign’.

Attribute: regard something as being caused by.

from L. attribut- ‘allotted’: both from attribuere, from ad- ‘to’ + tribuere

‘assign’.



Epistemological limits in radioepidemiologyEpistemological limits in radioepidemiology

26 July, 2012


Control group“N” people“C” cancers“n” probability of ‘natural’ cancer

Control group““NN”” peoplepeople““CC”” cancerscancers““nn”” probability of probability of ‘‘naturalnatural’’ cancercancer

Exposed group“N” people“E” cancers“n” probability of ‘natural’cancer‘pD’ probability of ‘radiation’ cancer

Exposed group““NN”” peoplepeople““EE”” cancerscancers““nn”” probability of probability of ‘‘naturalnatural’’cancercancer‘‘ppDD’’ probability of probability of ‘‘radiationradiation’’ cancercancer

26 July, 2012


E= n N

+ pd D N

Numberof

cancersin

exposedgroup

C=n N

Numberof

cancersin

controlgroup

C=n N

Numberof

cancersin

controlgroup

E-C

Difficult to detect!

26 July, 2012


Limitation of knowledge in epidemiology

The standard deviation is

= 2 n N + pd D N If the excess cancers are to be detected with a statistical

confidence of 95%

E – C > 2

The standard deviation is

= 2 n N + pd D N If the excess cancers are to be detected with a statistical

confidence of 95%

E – C > 2

26 July, 2012


Epidemiological limit

Operating algebraically and as n >> pd D,

N > constant / D2

which is the equation giving the number of people, N, needed for detecting excess cancers at dose D.

Operating algebraically and as n >> pd D,

N > constant / D2

which is the equation giving the number of people, N, needed for detecting excess cancers at dose D.

(Constant = 8 n / pd2)

26 July, 2012

264264WNU, ,

10 2

10 1

10-0

10-1 10 2 10 4 10 6 10 8

Dose (Dose (mSvmSv))

PeoplePeople

knowledgeknowledge

unprovableunprovable

1 1 mSvmSv10 9 p.

SOLID CANCERS

26 July, 2012

265265WNU, ,

10 2

10 1

10-0

10-1 10 2 10 4 10 6 10 8


PeoplePeople

~1 ~1 mSvmSv

HEREDITABLE EFFECTS

~10~1012 12 people!people!

knowledge(very limited)

knowledge(very limited)


26 July, 2012

C H E R N O B Y LC H E R N O B Y L

267

268

Radiation Doses

Average over 10 years 8 mSv

For life 13 mSv

Average over 10 years 8 mSv

For life 13 mSv

269

annual dosemSv/year

~100

~ 10

~ 2.4

~ 1

Natural Background


AVERAGE AVERAGE

MINIMUM MINIMUM

VERY HIGHVERY HIGHFew peopleIn few areas

Many peopleIn many areas

Majority of peoplearound the world

Chernobyl for life Chernobyl for life

270270WNU, ,

10 2

10 1

10-0

10-1 10 2 10 4 10 6 10 8


PeoplePeople

SOLID CANCERS in Chernobyl(except thyroid cancers in children)

Chernobyl doses Chernobyl doses ~10 ~10 mSvmSv

Chernobyl residents residents in strict control areas in strict control areas

~300 000~300 000

knowledgeknowledgeunprovableunprovable

26 July, 2012

272272WNU, ,

10 2

10 1

10-0

10-1 10 2 10 4 10 6 10 8


ChildrenChildren

Thyroid Cancer

knowledge(very expanded)knowledge

(very expanded)


26 July, 2012

273

274WNU, , 274

Thyroid cancer in children in Belarus

Thyro id cancer in ch ild ren in B elarusThyro id cancer in ch ild ren in B elarusThyroid ca ncer in children in Be la rus

0

20

40

60

80

100

120

140

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

Num

ber o

f cas

es

Total

0-4

5-9

10-14

26 July, 2012

275

The ‘liquidators’“ЛIКВIДАТОРИ”

The ‘liquidators’“ЛIКВIДАТОРИ”

278278WNU, ,

10 2

10 1

10-0

10-1 10 2 10 4 10 6 10 8


PeoplePeople

LiquidatorsLiquidators’’ av.doses av.doses ~10 ~10 mSvmSv

Chernobyl liquidators liquidators ~160 000~160 000

DETECTABILITY OF LEUKÆMIAS

knowledgeknowledge


26 July, 2012

279WNU, ,

Dose (mSv)


Certainty(100%)




Limit ofpathologyLimit of

pathology

26 July, 2012

280WNU, ,

Dose (mSv)

Certainty(100%)


PlausiblePlausible Collective estimate

Collective estimate

Individual diagnosisIndividual diagnosis

26 July, 2012


281WNU, ,

Dose (mSv)

Certainty(100%)


No attribution

No attribution

Collective attributionCollective attribution

Individual attributionIndividual attribution

26 July, 2012


282

Take away points

1. It is plausible that radiation exposure at low

doses be detrimental to public health and,

therefore: people shall be protected against

radiation exposure at any dose however small.

2. It is impossible and therefore incorrect to

attribute health effects to low-dose radiation

exposure situations.

1. It is plausible that radiation exposure at low

doses be detrimental to public health and,

therefore: people shall be protected against

radiation exposure at any dose however small.

2. It is impossible and therefore incorrect to

attribute health effects to low-dose radiation

exposure situations.26 July, 2012 WNU, ,

283WNU, ,


+541163231758


Argentina


26 July, 2012

Documents

Gonzalez Radiation WNU Oxford 2012 Abel... · 2012-11-11 · 1 Radiation Protection 1. Epistemology of Radiation 2. International Paradigms 1. Epistemology of Radiation 2. International