Radiation Protection Radiation Protection

WNU–Summer Institute 2012 

Christ Church Lecture Hall, University of Oxford, UK; August 2th Christ Church Lecture Hall, University of Oxford, UK; August 2 , 2012 

th , 2012 

Radiation Protection 

1. Epistemology of Radiation 

2. International Paradigms 

Abel J. González 

Vice-President Vice Vice-President President of the International Commission on Radiological Protection Protec Protection tion (ICRP) 

Representative to the United Nations Scientific Committee on the th the e Effects of Atomic Radiation (UNSCEAR) 

Member of the Commission of Safety Standards of the IAEA 

Autoridad Regulatoria Nuclear; Nuclear Nuclear; ; Av. Av. Av. del Libertador 8250; (C1429BNP) ( (C1429BNP) C1429BNP) Ciudad de Buenos Aires, Aires Aires, , Argentina 

+54 +54 +54 11 6323 1758; (official) (official) (official) agonzalez@arn.gob.ar; (private) (private) (private) abel_j_gonzalez@yahoo.com 

1

Content 

FIRST PART 

Epistemology: 

Radiation Science and its Limitations 

Quantification 

Levels 

Effects 

SECOND PART 

Protection Paradigm 

The International Radiation Protection System 

The International Organizations 

Radiation Protection Recommendations 

Global Regime 

2

FIRST PART 

Epistemology: 

Radiation Science and its Limitations 

26 July, 2012 3

(1) 

Quantification 

of Radiation Exposure 

WNU-Summer Institute 

4

Radioactive 

substance 

(radioactivity 

measured in 

Becquerels 

[or curie]) 

Radiation emitted 

(radiation fluence) 

Absorbed dose 

(incurred due to 

radioactivity 

inside the body 

or radiation fluence 

from outside 

–measured in gray 

[or rad]) 

5

Activity,A 

(bequerel or curie) 

Fluence,Φ 

Absorbed dose, D 

(gray or rad)

Absorbed dose, D 

(gray or rad) 

Radiation 

weighting factor, w R 

Equivalent dose, H T 

(sievert or rem)

Equivalent dose, H T 

(sievert or rem) 

Tissue 

weighting factor), wT Effective dose, E 

(sievert or rem)

Activity 

(Bq) 

Fluence 

(cm-2 Fluence 

(cm ) -2 ) 

Conversion 

Factor 

(Sv Bq-1 Conversion 

Factor 

(Sv Bq ) -1 ) 

Absorbed 

Dose 

(Gy) 

Conversion 

Factor 

(Sv cm2 Conversion 

Factor 

(Sv cm ) 2 ) 

w R 

Equivalent 

Dose (organ) 

(Sv) 

w T 

Efective 

Dose 

(Sv) 

9

(2) 

International Estimates of Global 

Radiation Exposure Levels

Natural 

Cosmic Cosmic rays 

Terrestrial 

Terrestrial 

Inhalation 

Inhalation 

[radon] 

Sources 

Artificial 

Medical Medical 

Military Military 

Nuclear Nuclear Power 

Occupational 

Occupational 

Accidents 

Accidents 

11

Natural Background 

Few people 

In few areas 

Many people 

In many areas 

Majority of people 

around the world 

~100 

~ 10 

~2.4 

~1 

annual dose 

mSv/year 

VERY HIGH 

TYPICALLY HIGH 

AVERAGE 

MINIMUM 

12

OSU, Stillwater, OK, USA, February 2008 

13

Exposure to natural sources 

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 

highest…up to above 100! 

14

Medical 

sources

Radio-diagnostic procedures 

Average annual frequency per 1000 

1308 

High 

Health-care 

332 

Medium 

Health-care 

20 

Low 

Health-care 

482 

Global 

average 

16

Annual average per-caput dose 

(in mSv) 

1.88 

High 

Health-care 

0.32 

Medium 

Health-care 

0.03 

Low 

Health-care 

0.61 

Global 

average 

17

No. of procedures (millions) 

70.0 

60.0 

50.0 

40.0 

30.0 

20.0 

10.0 

0.0 

procedures by year (millions) 

Annual growth > 10%/yr 

Annual growth of >10% per yea 

U.S. population < 1%/yr 

18.3 

19.5 

21.0 

22.6 

CT scans by year in US (millions 

25.1 

26.3 

Computerized tomography (CT) 

30.6 

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

34.9 

39.6 

45.4 

50.1 

53.9 

57.6 

62.0 

18

Military activities 

20

NUMBER 

150 

100 

50 

0 

50 

100 

1945 

Nuclear weapons tests 

Atmospheric tests 

Underground tests 

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 

21

Annual effective dose (mSv) 

Doses due to atmospheric nuclear testing 

0.12 

0.1 

0.08 

0.06 

0.04 

0.02 

0 

1945 1955 1965 1975 1985 1995 2005 

Year 

22

Civil nuclear power 

23

Global average levels 

Natural 

sources 

80% 

Source: UNSCEAR 2000 Report 

Medical 

examinations 

20% 

Weapons 

fallout 

Occupational exposures 

25

Annual effective dose (mSv) 

6 

5 

4 

3 

2 

1 

0 

Nuclear industry 

Millions 

exposed 

Man-made sources Natural sources 

Defence 

Medicine 

Coal mining 

Other mining 

Aircrew 

0 10 20 30 

Other workplaces 

Artificial 

Natural 

26

Global annual per caput dose (mSv) 

27

Annual per caput dose (mSv) for USA 

28

In summary: 

Patients are 

being exposed 

to increased 

radiation 

levels 

29

(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) 


30

26 July, 2012 

Chromosomes 


DNA 

31

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32

Chromosomes 

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are a 

condensed 

packing of 

DNA 

1400 

nano 

meters 

0.2 meters! 

2 nanometers 

33

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34

The Enciclopedy of Life 

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Bases Letters 

Codons Words 

Introns Interruptions 

Exons Paragraphs 

Genes Chapters 

Chromosomes Volumes 


35

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Radiation harm to DNA 

WNU-Summer Institute 36

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Mutation! 


37

Many other 

mutations occur due 

to DNA miscopying, 

thermal agitation, etc. 

Usually they can be 

correctly repaired by 

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copying the DNA 

template. 


39

What is the 

problem then?: 

the chromosome is 

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a very complex 

packing of DNA 


nucleosomes 

41

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0.5 Mev 


10 nm 

2nm 

43

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44

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Chromosomes deletions 


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Chromosomes Translocations 


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Chromosomal aberrations are easily 

identifiable in the microscope 


48

adiation 

hits a cell 

nucleus! 

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No change 

DNA mutation 

49

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Probability 

of mutation 

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


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

50

DNA mutation 

p a D a D D 3)Cell survives 

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1) Mutation 

repaired 

2) Cell dies 

but mutated 


No effects 

Deterministic 

Effects (>~1Sv) 

Stochastic 

effects 

51

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First possible outcome: 

mutation is repaired 

Mutation 

repaired 

Viable Cell 


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Second possible outcome: 

cell killing (apoptosis) 

Unviable Cell 


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Cell killingat around 1000mSv 

deterministic effects:burns, organ failure, 

death! 

100% 

Probability 

Acute dose 

> ~1000 mSv 


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). 

55

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Third possible outcome: 

viable but mutated cell 

Cell survives 

but mutated 

Altered process 


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Normal process 


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Altered process 


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Cell survives 

but mutated 

Stochastic effects 


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Stochastic effects 

Cancer 

Hereditable 

Antenatal 


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Cancer 


65


mutates DNA 

26 July, 2012 

Prevalent opinion on 

radiation-induced cancer 

Tumour 

promotion 

Failure to 

repair DNA 

INMUNE SYSTEM 

Malignant 

conversion 

Viable cell with 

carcinogenes 

Metastasis of 

malignancy 

66

Estimates of the Risk of Cancer due to 

26 July, 2012 

Radiation Exposure 


68

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Radioepidemiology 

(Epidemia (Gk): prevalence of disease) 


69

Control group 

“N” people 

“C” cancers 

“n” probability of 

‘natural ‘natural’ natural’ cancer 

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Exposed group 


“E” cancers 


‘natural ‘natural’cancer 

natural’cancer cancer 

‘p D’ probability of 

‘radiation ‘radiation’ radiation’ cancer 

70

26 July, 2012 

Difficult to 

assess! 

C 

=n N 

Number 

of 

cancers 

in 

control 

group 

E-C 


E 

= n N 

+ 

p d D N 

Number 

of 

cancers 

in 

exposed 

group 

71

UNSCEAR has reviewed many many 

epidemiological data on effects of radiation in 

26 July, 2012 

exposed populations 


72

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The radium dial painters,… 


…the early x-rays doctors and patients… 

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..the Mayak cohort of workers… 

MAYAK 


..the survivors of Hiroshima y Nagasaki.. 

..the survivors of Hiroshima y Nagasaki.. 

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76

…all these victims of radiation exposure have 

unwillingly contributed to the 

UNSCEAR’s epidemiological assessments. 

26 July, 2012 


77

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Cohort of Hiroshima & Nagasaki 

(LIFE SPAN STUDY, LSS) 

Slide 6 

Mt.Hiji 


Solid Cancer Mortality 

47 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%) 

26 July, 2012 

Preston et al, Radiat Res 160:381-407, 2003 

(updated figures) 

79

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. 

26 July, 2012 

UNSCEAR Estimates of NOMINAL Cancer Risk 


26 July, 2012 

Hereditable Effects 


81

Prevalent opinion on the induction of 

hereditable effects from radiation exposure 


Mutes the DNA 

of a Germinal 

26 July, 2012 

Cell 

Failure to 

Repair 

Viable Sperm 

or Ovum 

Containing 

Defective Genes 


The risk is so low that the estimation has 

to be based on animal studies 

26 July, 2012 


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 


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Antenatal Effects 


85

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1000mSv 

= IQ 


26 July, 2012 

Shift in the IQ curve: 

30 IQ units per 1000 mSv incurred during the 8-15 weeks 

1000mSv 

= IQ 


Latest news 

89

Summary 

of the scientific knowledge 

93

Likelihood 

of health 

effects 

100% 

(certainty) 

~ 10% 

~5% 

(UNSCEAR 

estimate) 

~ 1% 

Approx. 

lower bound of 

epidemiological 

knowledge 

Estimated Estimated likelihood likelihood of of cancer 

cancer 

Subjective 

(Bayesian) 

estimation 

~0,1 

Approx. 

lower bound 

of pathological 

knowledge 

Tissue reactions 

Clinical diagnosis 

(individual pathology) 

Cytogenetic exposure indicators 

General radiobiological information 

radiation 

syndromes 

and death 

Increase incidence of malignancies 

Statistical estimates (epidemiology of populations) 

Frequentist 

(Bernoullian) 

estimation 

~1 ~10 

Dose (Sv) 

94

Likelihood 

of health 

effects 

100% 

(certainty) 

~ 10% 

~5% 

(UNSCEAR 

estimate) 

~ 1% 

Typical 

Background 

Approx. 



knowledge 

Estimated Estimated likelihood likelihood of of cancer cancer 

~0,1 

Region of inference 

of radiation risks 

Approx. 

lower bound 


knowledge 

Increased 

syndromes 

and death 

Dose (Sv) 

~1 ~10 

Region of individual 

attribution of effects 

Region of collective attribution of effects 

95

Likelihood 

of health 

effects 

100% 

(certainty) 

~ 10% 

~5% 

(UNSCEAR 

estimate) 

~ 1% 

Typical 

Background 

Approx. 



knowledge 

Estimated Estimated likelihood likelihood of of cancer cancer 

~0,1 

Region of inference 

of radiation risks 

Approx. 

lower bound 


knowledge 

Increased 

syndromes 

and death 

Dose (Gy) 

~1 ~10 

Region of individual 

attribution of effects 

Region of collective attribution of effects 

96

Total 

background 

incidence of 

effects 

Presumed 

radiation-related 

background incidence 

Radiation-unrelated 

background 

incidence 

Postulated 

likelihood of health effects 

Background 

annual dose 

(average 2.4, 

typical 10 mSv y -1 ) 

Incremental dose 

0.005%/mSv 

Nominal incremental 

likelihood 

of health effects 

Dose 

97

26 July, 2012 

Take away points 


98

Activity bequerel 

Dose sievert (1 Sv = 1000 milliSieverts) 

milliSieverts 

milliSieverts) ) 

(mSv (mSv) mSv) 

Background 2.4 mSv/y 

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

Medical 

Nuclear 

26 July, 2012 WNU-Summer Institute 99

Dose 

Very low dose: 

about 10 mSv or less 

Low dose: 

towards 100 mSv 

Moderate dose: 

towards 

1000 mSv (acute whole 

body dose) 

High dose: 

above 1000 mSv (acute 

whole body dose) 

Effects on 

individuals 

No acute effects; 

extremely small additional 

cancer risk 

No acute effects; 

subsequent additional 

cancer risk of less than 1% 

Nausea, vomiting possible, 

mild bone marrow 

depression; 

subsequent additional 

cancer risk of about 10% 

Certain nausea, likely bone 

marrow syndrome; high risk 

of death from about 4000 

mSv (without medical treatment). 

Significant additional 

cancer risk! 

Consequences for 

an exposed 

population 

No observable increase in 

the incidence of cancer, even 

in a large exposed group 

Possible observable increase 

in the incidence of cancer, if 

the exposed group is very 

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

Probable observable 

increase in the incidence of 

cancer, if the exposed group 

is more than a few hundred 

people 

Observable increase in the 

incidence of cancer 

100

26 July, 2012 

… 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 


101

Remember! 

1. Radiation exposure at high acute levels, 

e.g. above several thousand of millisieverts 

is 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

agonzalez@arn.gob.ar 

26 July, 2012 

Thank you! 

Av. del Libertador 8250 

Buenos Aires 

Argentina 

WNU, , 

+541163231758 

103

Additional information to the 

FIRST PART 

26 July, 2012 104

26 July, 2012 

A close book? 


The Health Effects 

of Radiation 

105

Physics 

and 

chemistry 

Biology 

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

Exposure 

Physiology 

? 


Epidemio- 

logy 

Time 

Manifestation 

of 

effects 

The time scale of the phenomena limits knowledge. 

26 July, 2012 

106

26 July, 2012 


107

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 

26 July, 2012 


26 July, 2012 

Cardiovascular diseases 


109

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Chernobyl workers, 

atomic bomb survivors, and 

radiotherapy patients … 

… seem to suffer a higher risk of 

cardiovascular diseases. 


110

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‘Non-targeted’ 

and 

delayed effects 

of radiation exposure 


111

26 July, 2012 

Adaptive Response 

+ 

Mutation 

Mutations 

Mutations 


26 July, 2012 

conditioning 

dose 

challenging 

dose 

conditioning 

dose 

Adaptive response 

+ 

challenging 

dose 

 

 

 

response 

response 

response 


The role of apoptosis 

(cell killing by mutations) 

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

... 

26 July, 2012 

..then.. hormesis! hormesis hormesis! 


26 July, 2012 

Mutation 

Rate 

Apoptosis 

hormesis 

Carcinogenesis 

Dose rate 


Apoptosis 

115

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Genomic instability … 

Genomic instability … 

… or … increased rate of acquisition of 

alterations in the genome. 


Basic paradigms of radiobiology 

Damage fixed in DNA of irradiated cell, 

if not lethal, transmitted to descendant 

Effects occur in cells whose 

nucleus crossed by radiation

Challenge to the paradigm 

Mutation Chromosomal 

aberration 

Genomic instability 

Cellular 

death 

Mitotic failure: 

aneuploid 

Micronucleus

26 July, 2012 


119

Bystander effects 

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

26 July, 2012 

cells to convey damage to neighbouring cells 

not directly irradiated. 

120

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“Bystander” effect 

121

26 July, 2012 

Signals via intercellular unions 

(Azamm 2001) 

Signals via medium/plasma 

ROS 

Nitric oxide 

Cytokines 

TGF 

(Lehnert 1997) 

122

Clastogenic plasma factors 

There is a large body of evidence that blood plasma from 

26 July, 2012 

irradiated animals and humans can contain so-called 

“clastogenic plasma factors” capable of inducing 

chromosomal damage in unexposed cells. 


26 July, 2012 


124

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. 

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

26 July, 2012 


26 July, 2012 

Effects in another organ 

Irradiation of 

an organ 


126

26 July, 2012 

Effects of ionizing radiation on the 

immune system 


127

Does radiation exposure affect the immune system? 

26 July, 2012 

Infections 

Cancer 

Immune 

system 


SECOND PART 

Protection Paradigm: 

The International Radiation Protection System 

26 July, 2012 129

(1) 

The International Organizations 

26 July, 2012 WNU-Summer Institute 

130

Epistemology of radiation 

Method, validity and scope of the scientific 

knowledge on radiation 

Radiation Protection Paradigm 

Conceptual model for keeping people protected 

Global Radiation Safety Regime 

Establishing international safety standards and 

providing for their global application 

26 July, 2012 131

UNSCEAR 


132

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 

133

Member States on UNSCEAR 

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 

134

The latest UNSCEAR reports 

Sources Efects 

26 July, 2012 

Hereditable 

New 

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 

WNU-Summer Institute 135 

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

135

ICRP 


137

26 July, 2012 

The International Commission 

on Radiological Protection (ICRP) 

Registered Registered charity established to advance 

radiological protection for the public benefit 

by providing recommendations and guidance. 

138 


First ICRP meeting 1928 

139

140

141

IAEA 


142

26 July, 2012 

The International Atomic 

Energy Agency (IAEA) 

143 


143

The IAEA is the only organ within the UN 

system with specific statutory responsibilities 

on radiation protection and safety 


144

to establish 

standards 

IAEA 

statutory safety functions 

to provide for 

their application 

to service international conventions 


26 July, 2012 145

IAEA Safety Standards 

http://www-ns.iaea.org/standards/ 

146

International Labour Organisation 

147

Radiation Protection Convention No. 115 

(1960) Date of entry into force: 17.6.1962 

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 

48 ratifications 

Ghana 7.11.1961 

Norway 17.6.1961 

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 

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 

Latvia 8.3.1993 

Switzerland 29.5.1963 

Lebanon 6.12.1977 

Luxembourg 8.4.2008 

Mexico 19.10.1983 

Netherlands 29.11.1966 

Nicaragua 1.10.1981 

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 

148

(2) 

The International Radiation 

Protection Recommendations 

The conceptual model for keeping people safe from radiation exposure 

26 July, 2012 149

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). 

150

Total 

background 

incidence of 

effects 

Presumed 

radiation-related 

background incidence 

Radiation-unrelated 

background 

incidence 

Postulated 

likelihood of health effects 

Background 

annual dose 

(average 2.4, 

typical 10 mSv y -1 ) 

Incremental dose 

0.005%/mSv 

Nominal incremental 

likelihood 

of health effects 

Dose 

151

ICRP had to introduce the concept of 

‘detriment-adjusted’ 

‘nominal’ risk coefficients 

152

Detriment-adjusted Nominal Risk Coefficients 

Risk Coefficient: A numeral, expressed in % Sv-1 Risk Coefficient: A numeral, expressed in % Sv , which 

-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 including 

inter alia the weighted plausibility of fatal and non-fatal 

harm, and life-lost should the harm actually occur. 

153

Detriment-adjusted nominal risk coefficients 

Nominal 

Population 

Whole 

Adult 

Cancer & 

leukæmia 

5.5 

4.1 

[% Sv -1 ] 

Hereditable 

0.2 

0.1 

Total 

5.7 

4.2 

Rounded value used in RP standards~5%Sv-1 Rounded value used in RP standards~5%Sv-1 154

Time 

Protection basic dogma 

Shielding 

Distance 

……..but…..it depend on the situation! 

155

Time? 

156

The principles of 

radiological protection

The 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 

• Any decision that alters the radiation exposure 

situation should do more good than harm.

Justification 

Good > bad

adioactive discharges 

(bad) 

Is the installation justied? 

good > bad? 

Electricity) 

(good)

Was evacuation justified?

Justification!

The 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.)

Detriment 

Detriment +Social cost 

Optimal 

Social cost 

RP level 

167

The Principle of Dose Limitation 

• The total dose to any individual should not 

exceed appropriate limits, constraints or 

reference levels.

Restrictions: Restrictions: 

dose limits and constraints 

Natural 

background 

radiation 

Activity introduced 

Expected 

additional 

dose 

26 July, 2012 169

Nuclear power 

Mining 

Wastes 

Transport 

Dose limit 

Industry 

Hospitals 

26 July, 2012 170

Source constraint 

26 July, 2012 171

26 July, 2012 

Extant 

dose 


Averteble 

dose 

Reference 

level 

172 

172

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 

173

How to protect the future?

D 

Doses after 1 year of operation 

1 st year 2 nd year 3 rd year …. … …. n th year 

26 July, 2012 175 

t

Doses after 2 years of operation 

D 

2 nd year 

3 rd year 

4 th year …. 


26 July, 2012 176 

… 

…. 

t

Doses after 3 years of operation 

D 

2 nd year 

3 rd year 

3 rd year 

4 th year 

5 th year 

4 th year …. 


26 July, 2012 177 

…. 

… 

… 

…. 

t

CONTROL 

EQUILIBRIUM: BUILD-UP BUILD UP 

178

Types of exposure situations

Types of exposure situations 

• Planned exposure situations 

• Emergency exposure situations 

• Existing exposure situations

Planned exposure situations, 

are situations involving the planned 

introduction and operation of sources. 

(…previously categorised as practices.)

Planned exposure situation 

Regulatory control 

Natural 

background 

Effective 

dose 

Practice 

26 July, 2012 182

Emergency exposure situations, 

• are unexpected situations such as those 

that may occur during the operation of a 

planned situation, or from a malicious act.

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.

Emergency exposure 

situations 

Extant 

dose 

Existing exposure 

situations 

Avertable 

dose 

Regulatory 

ambition 

26 July, 2012 2009 WNU-Summer Institute 

185

3 systems 

homogeneous, coherent and consistent….but distinct 

Patients 

Occupational 

Public 


186

Doses to be constrained are 

those committed in a year 

rather than 

those incurred in a year! 


26 July, 2012 187

Patients 

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

• Radiodiagnosis 

• Radiotherapy 


188

Guidance for the 

protection of 

patients in 

radio-diagnosis 

radio diagnosis 

Fluoroscopy Fluoroscop 

Vertebral 

Torax rax 

100 

~ 10 

~ 1 

Doses in mSv 

HIGH 


TYPICAL 

MINIMAL 

189

TRAINING..!! 

190

Workers 

(voluntary and individually monitored exposure) 

Monitored worker 

Occupational 

exposure: 

ALL exposure of 

workers incurred 

in the course of 

their work. 


193

Occupational 

Dose 

Restrictions 

mSv in a year 

1000 

500 

100 

50 

20 

Maximum 

(except life saving) 

Every very effort not no to exceed it 

All reasonable efforts effort 

not not 

to exceed it 

Annual dose limit 

Average dose limit 

Optimization 

of 

Protection 

26 July, 2012 194 

R 

E 

S 

C 

U 

E 

N 

O 

R 

M 

A 

L

The female worker: 

protecting the 

unborn and 

the infant 


195

Members of the Public 

(involuntary no-individually monitored exposure) 

26 July, 2012 196

Members of the Public 

(involuntary no-individually monitored exposure) 

Planned exposure 

situations 

(Practices) 

restrict 

the expected 

additional doses 

below 

individual dose limits 

and source constraints 

Existing & emergency 

exposure situations 

(Interventions) 

reduce 

the extant 

avertable doses 

below 

reference levels 

26 July, 2012 197

(planned) 

‘Practices’

Natural 

background 

radiation 

(planned) ‘Practices’ 

Restrictions: Restrictions: 

dose limits and constraints 

Activity introduced 

Expected 

additional 

dose 

26 July, 2012 199

Nuclear power 

Mining 

Wastes 

Transport 

Dose limit 

Industry 

Hospitals 

26 July, 2012 200

Doses to be constrained are 

those committed in a year 

rather than 

those incurred in a year! 



201

Restrictions on 

the dose 

attributable to 

practices 

mSv in a year 

(additional annual dose) 

1 

0.01 


Regulatory limit 

Optimization of protection 

 


Regulatory exemption 

202

‘Interventions’ 

(in existing and emergency situations) 

203

‘Interventions’ 

(in existing and emergency situations) 

Extant 

Dose 

Should 

it be 

reduced? 

Avertable 

Dose 

How 

much? 

Reference 

level 


204

CRITERIA FOR 

INTERVENING 

(Extant Annual Dose) 

100 

10 

1 


mSv in a year 

INTERVENTION 

ALMOST ALWAYS 

JUSTIFIABLE 

INTERVENTION 

MAY BE 

JUSTIFIABLE 

INTERVENTION 

IS NOT LIKELY TO BE 

JUSTIFIABLE 

205

Simplified 

summary of dose 

restrictions 

and reference 

levels 

(in mSv in a year) 

100 

20 

1 

0.01 

NO INDIVIDUAL/SOCIETAL BENEFIT ABOVE THIS 

Emergency Emergency workers 

Evacuation/relocation in emergencies 

High levels of existing controllable exposures 

Information, training, monitoring 

DIRECT OR INDIRECT BENEFIT TO THE INDIVIDUAL 

Occupational exposure 

Sheltering, stable iodine, in emergencies 

Existing exposures such as radon 

Comforters and carers to patients 

Information, training, monitoring or assessment 

SOCIETAL, BUT NO INDIVIDUAL DIRECT BENEFIT 

Normal situations 

No information or training, 

No individual dose assessment 

Exclusion, exemption, clearance 

206

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 

207

In paradigm choice there is no standard higher 

than the assent of the relevant community 

Decision-aiding Decision aiding Process 

based on radiation protection consideration 

Decision-making Decision making Process 

involving relevant ‘stakeholders’ 

searching for their informed consent 

26 July, 2012 208

(4) 

The International 

Regime 


209

The IAEA is the only organ within the UN 

system with specific statutory responsibilities 

on radiation protection and safety 


210

“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 Prize 

2005 


211

to establish 

standards 

IAEA 

statutory safety functions 

to provide for 

their application 




212

Legally Binding 

Conventions 

213

Convention on Early Notification of 

a Nuclear Accident 

214

Convention on Assistance in the Case of a 

Nuclear Accident or Radiological Emergency 

215

Convention on Nuclear Safety 

216

Joint Convention on the 

Safety of Spent Fuel Management and on the 

Safety of Radioactive Waste Management 

217

Convention on Physical Protection 

of Nuclear Material 

218

International 

Radiation Safety 

Standards 


219

Nuclear Safety 

Standards 

Committee 

(NUSSC) 

IAEA Board of Governors 

Commission 

on Safety Standards 

(CSS) 

Radiation Safety 

Standards 

Committee 

(RASSC) 

Waste Safety 

Standards 

Committee 

(WASSC) 

Transport Safety 

Standards 

Committee 

(TRANSSC) 

Expert Groups Expert Groups Expert Groups Expert Groups 

26 July, 2012 220

Long experience 

1962: first 

international 

standards. 

26 July, 2012 221

A large corpus of 

International 

Safety Standards 

is available 

26 July, 2012 222

Safety Standards Hierarchy 

Safety Fundamentals 

Safety Requirements 

Safety Guides 


223

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

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 

225

26 July, 2012 227

Provisions 

for the 

application 

of the 

standards: 

IAEA 

mechanisms 

providing 

TECHNICAL ASSISTANCE 

fostering 

INFORMATION EXCHANGE 

promoting 

EDUCATION & TRAINING 

coordinating 

RESEARCH & DEVELOPMENT 

rendering 

APPRAISAL SERVICES 

26 July, 2012 228

Example on how the system for 

establishing standards works: 

The Regulations for Safe Transport 


229


230

to Geneva 


231

232

233

234

235

236

237


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. 


238


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 

26 July, 2012 239 


Download into your computer 

the file 

González_Reading Material

agonzalez@arn.gob.ar 

26 July, 2012 

Thank you! 


Buenos Aires 

Argentina 

WNU, , 

+541163231758 

241

Additional information to the 

SECOND PART 

26 July, 2012 242

Epilogue 

Policy Implications: 

plausibility of effects at low doses 

versus 

their attributability 

26 July, 2012 WNU-Summer InstituteS 

243

Policy Implications on effects at low doses : 

The effects are 

probable and, therefore, 

plausible 

but, they are not 

provable! 

26 July, 2012 

Low-dose effects cannot be 

attributed 

to radiation exposure! 

S 

244

Certainty 

(100%) 

26 July, 2012 

Likelihood of 

Health Effect 

Limit of 

epidemiology 

epidemiology pathology 

WNU, , 2008 

Limit of 

pathology 

Dose (mSv) 

245

Certainty 

(100%) 

26 July, 2012 

Likelihood of 

Health Effect 

Plausible 

Epidemiology Pathology 

WNU, , 2008 

Collective 

estimate 

Dose (mSv) 

Individual 

diagnosis 

246

Certainty 

(100%) 

26 July, 2012 

Likelihood of 

Health Effect 

No 

attribution 

Epidemiology Pathology 

Collective 

attribution 

Dose (mSv) 

Individual 

attribution 

247

Dealing with uncertainties 

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

Plausibility 

Apparently reasonable or probable, 

without necessarily being so. 

from L. plausibilis, from plaus-, plaudere ‘applaud’. 


248

26 July, 2012 

ICRP Publication 99 

Low - Dose Extrapolation 

of Radiation Related 

Cancer Risk 


2006 

Charles E Land; Uncertainty, low-dose low dose extrapolation and the threshold hypothesis; J. Radiol. Radiol. 

Prot. 22 (2002) 1–7 

1 

249

Nominal statistical uncertainty distribution for excess lifetime 

risk of solid cancer mortality among atomic-bomb survivors 

26 July, 2012 

250 

Confidence limits 

7.5–12.5% Sv -1 


Uncertainty distribution for excess lifetime risk 

26 July, 2012 

(taking into account extrapolation to another population) 

Cumulative 

probability 

approximately 

log-normal 

log normal 

1.0- 

0.8- 

0.6- 

0.4- 

0.2- 

95% upper limit 

5% 

‘ 

2 

‘ 

4 

251 

‘ 

6 

‘ 

8 

15 May, 2004 IRPA11: Sievert Lecture 134 

‘ 

10 

‘ 

12 

‘ 

14 

Risk (%)/Sv 

confidence limits 

1.2–8.8% Sv-1 WNU-Summer Institute 251

26 July, 2012 

Cumulative 

probability 

1.0- 

0.8- 

0.6- 

0.4- 

0.2- 


5% 

‘ 

2 

‘ 

4 

‘ 

6 


‘ 

8 

8.8%/Sv 

‘ 

10 

‘ 

12 

‘ 

14 

Assuming a 

Risk (%)/Sv 

20% 

probability 

of threshold 

252

26 July, 2012 

Cumulative 

probability 

1.0- 

0.8- 

0.6- 

0.4- 

0.2- 


5% 

‘ 

2 

‘ 

4 

‘ 

6 


‘ 

8 

8.8%/Sv 

7%/Sv 

‘ 

10 

‘ 

12 

‘ 

14 

Assuming a 

Risk (%)/Sv 

50% 

probability 

of threshold 

253

26 July, 2012 

Cumulative 

probability 

1.0- 

0.8- 

0.6- 

0.4- 

0.2- 


5% 

‘ 

2 

‘ 

4 

‘ 

6 


5%/Sv 

‘ 

8 

8.8%/Sv 

‘ 

10 

‘ 

12 

‘ 

14 

Assuming a 

Risk (%)/Sv 

80% 

probability 

of threshold 

254

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. 

255 


Policy Implications: 

plausibility of effects at low doses 

versus 

their attributability 

26 July, 2012 WNU-Summer InstituteS 

256

Likelihood of radiation health effects 

Certainty 

(100%) 

26 July, 2012 

Likelihood 

Uncertainty! 

0.005%/mSv for 

cancer 

0.0002%/mSv for 

hereditable 

Doses 


Attributability 

Attribute: regard something as being caused by. 

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

‘assign’. 


258

26 July, 2012 

Epistemological limits in radioepidemiology 


259

Control group 


“C” cancers 


‘natural ‘natural’ natural’ cancer 

26 July, 2012 


Exposed group 


“E” cancers 


‘natural ‘natural’cancer 

natural’cancer cancer 

‘p D’ probability of 

‘radiation ‘radiation’ radiation’ cancer 

260

26 July, 2012 

Difficult to 

detect! 

C 

=n N 

Number 

of 

cancers 

in 

control 

group 

E-C 


E 

= n N 

+ 

p d D N 

Number 

of 

cancers 

in 

exposed 

group 

261

Limitation of knowledge in 

The standard deviation is 

epidemiology 

= 2 n N + p D N d N d 

If the excess cancers are to be detected with a statistical 

26 July, 2012 

confidence of 95% 

262 

E – C > 2 


Epidemiological limit 

Operating algebraically and as n >> p d D, 

N > constant / D2 N > constant / D2 which is the equation giving the number of people, 

N, needed for detecting excess cancers at dose D. 

26 July, 2012 

(Constant = 8 n / p d 2 ) 

263 


Dose (mSv ( mSv) 

10 2 

10 1 

10 -0 

10 -1 10 2 10 4 10 6 10 8 

26 July, 2012 

unprovable 

1 mSv 

WNU, , 

SOLID CANCERS 

knowledge 

10 9 p. 

People 

264


10 2 

10 1 

10 -0 

10 -1 10 2 10 4 10 6 10 8 

26 July, 2012 

unprovable 

~1 mSv 

~10 12 people! 

WNU, , 

HEREDITABLE EFFECTS 

knowledge 

(very limited) 

People 

265

C H E R N O B Y L

267

Radiation Doses 

Average over 10 years 8 mSv 

For life 13 mSv 

268

Natural Background 

Chernobyl for life 

Few people 

In few areas 

Many people 

In many areas 

Majority of people 

around the world 

~100 

~ 10 

~2.4 

~1 

annual dose 

mSv/year 

VERY HIGH 


AVERAGE 

MINIMUM 

269


10 2 

10 1 

10 -0 

Chernobyl doses 

~10 mSv 

10 -1 10 2 10 4 10 6 10 8 

26 July, 2012 

unprovable 

WNU, , 

SOLID CANCERS in Chernobyl 

(except thyroid cancers in children) 

Chernobyl residents 

in strict control areas 

~300 000 

knowledge 

People 

270


10 2 

10 1 

10 -0 

10 -1 10 2 10 4 10 6 10 8 

26 July, 2012 

unprovable 

WNU, , 

Thyroid Cancer 

knowledge 

(very expanded) 

Children 

272

273

Thyroid cancer in children in Belarus 

Number of cases 

Thyroid cancer in children in Belarus 

Thyroid 140 cancer in children in Belarus 

26 July, 2012 

120 

100 

80 

60 

40 

20 

0 

1986 

1987 

1988 

1989 

274 

1990 

1991 

1992 

1993 

1994 

1995 

Total 

1996 

0-4 

5-9 

10-14 

1997 

WNU, 274 ,

The ‘liquidators’ 

“ЛIКВIДАТОРИ” 

275


10 2 

10 1 

10 -0 

Liquidators’ Liquidators av.doses 

~10 mSv 

10 -1 10 2 10 4 10 6 10 8 

26 July, 2012 

unprovable 

WNU, , 

DETECTABILITY OF LEUKÆMIAS 

Chernobyl liquidators 

~160 000 

knowledge 

People 

278

Certainty 

(100%) 

26 July, 2012 

Likelihood of 

Health Effect 

Limit of 

epidemiology 


WNU, , 

Limit of 

pathology 

Dose (mSv) 

279

Certainty 

(100%) 

26 July, 2012 

Likelihood of 

Health Effect 

Plausible 


WNU, , 

Collective 

estimate 

Dose (mSv) 

Individual 

diagnosis 

280

Certainty 

(100%) 

26 July, 2012 

Likelihood of 

Health Effect 

No 

attribution 


WNU, , 

Collective 

attribution 

Dose (mSv) 

Individual 

attribution 

281


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, 282 ,

agonzale@arn.gob.ar 

26 July, 2012 

Thank you! 


Buenos Aires 

Argentina 

WNU, , 

+541163231758 

283

Radiation Protection Radiation Protection

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