p. 1 

# PICK-UPDATE : 3/15/200 7 BO X O F 

# 7?o Ste p 2 : FO R ASR C INTERNA L US E ONL Y 

### (PAR T B o

f B )



# EP A DOCKE T ID : 102RQ-R N 1 ) 102RQ-RN-5-1 6 3 ) 102RQ-RN-5-1 8 5 ) 102RQ-RN-5-2 0 7 ) 102RQ-RN-5-2 2 9 ) (f02RQ-RN-5-24> > 11 ) 102RQ-RN-5-2 6 13 ) 102RQ-RN-5-2 8 15 ) 102RQ-RN-5-3 0 17 ) 102RQ-RN-6- 1 19 ) 102RQ-RN-6- 3 21 ) 102RQ-RN-6- 5 23 ) 102RQ-RN-6- 7 25 ) 102RQ-RN-6- 9 27 ) 102RQ-RN-6-1 1 29 ) 102RQ-RN-6-1 3 31 ) 102RQ-RN-6-1 5 33 ) 102RQ-RN-6-1 7 35 ) 102RQ-RN-6-1 9 37 ) 102RQ-RN-6-2 1 39 ) 102RQ-RN-6-2 3 Ste p 3 : FO R ASR C INTERNA L US E ONL Y 

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Ste p 1 : FO R ASR

C INTERNA L US E ONL Y /" O Are ther e more document s fo r thi s Docke t i n anothe r box ? *YE S //N O J *Fil l ou t Continuatio n Shee t an d g o t o Ste p 2 — ' Interna l SFUN D Bo

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Ontario KOJ

UO. Canada !2 5PU. England

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. Upton , Siony Brook J
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9 

### RADIATIO N PROTECTIO N

ICR P PUBLICATIO N 2 6


# Recommendations ofthe International

Commission on Radiological

Protection

(ADOPTE D JANUAR Y 17 , 1977 )



### J PUBLISHE D FO R Th e Internationa l Commissio n o n Radiologica l Protectio n B Y 

### PERGAMO N PRES S OXFOR D : NE W YORK: FRANKFUR TP. 3 

# Annal s o f th e IC R Publishe d o n behal f o f th e Internationa l Commissio n o n Radiologica l Protectio n U . S . NUCLEA R R I LIBRAR Y WASHINGTON , Dj-

C STO P 55 5



### DEC 3 

### 197 9

Editor : F . D . SOWB Y ICRP. Sutton, Surrey
International Commissio n o n Radiologica l Protectio n Chairman : Dr
. C
. G
. Stewart , Atomic Energy of

Canada Limited. Chalk

River. Ontario KtU

UO. Canada Scientific Secretary : Dr
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th e Mai n Commissio n o f th e ICR P C
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River A
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. Upton
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### RADIATIO N PROTECTIO N P. 4

ICR P PUBLICATIO N 2 6


# Recommendations ofthe International

Commission on Radiological

Protection

(ADOPTE D JANUAR Y 17 , 1977 )



### PUBLISHE D FO R Th e Internationa l Commissio n o n Radiological Protectio n A . Introduction B . Objectives o

f Radiatio r C . Basi c Concept s Detriment Dose equivalent Collective dose eqi Dose-equivalent

cc Committed

dose ec D
. Radiobiological Consi d Dose-respons e relat

h Implications fro

m as ; Significant

volume. Rate of dose accun Tissue s a tris k Gonads Red bone marrow Bone Lung Pulmonary lymp Thyroid Breast Risk of cancer in al, Total stochastic risl Lens Skin Children andfoetui Tissues of low sensi Other effects h. Th e Syste m o f Dos e Li m The bases for decidi Dose-equivalent

lmP. 5



### CONTENT S


# fthe non on tion A . Introductio n

dea l Protectio n 3
. Objective s o f Radiatio n Protectio n C . Basi c Concept s Detriment Dose equivalent Collective dose equivalent Dose-equivalent

commitment Committed

dose equivalent D . Radiobiologica l Consideration s Dose-respons e relationship s Implication s fro m assumption s abou tdose-respons e relationship s Significant

volumes and

areas Rateofdose.accumulation Tissue s a tris k Gonads Red bone marrow Bone Lung Pulmonary lymphoid

tissue Thyroid Breast Risk of cancer in all other tissues Total stochastic risk

from uniform whole body irradiation Lens Skin Children andfoetuses Tissues of low sensitivity Other effects Paragrap h Numbe r 1 6 5 5 .1 5 1 7 2 2 2 5 2 6 2 7 2 7 .3 1 3 2 .3 5 3 6 4 0 4 4 4 7 4 9 •5 2 5 5 51 .5 8 •60 6 1 6 3 65 6 6 6 7 E . Th e Syste m o f

Dos e Limitatio n The bases for deciding what

is reasonably achievable in dose reduction Dose-equivalent

limits--generai 6 8 7 2 7 7P. 6

I V RECOMMENDATION S O F TH E ICR P Natural radiation and

dose-equivalent

limits Medical exposure of

patients and

dose-equivalent

limits Implications

for non-stochastic effects Dose-equivalent

limits for workers Recommended

dose-equivalent

limits Planned special exposures Occupational

exposure of

women of

reproductive capacity Occupational

exposure of

pregnant women Dose-equivalent

limits for individual

members of

the public Exposure of

populations A ccidents and

emergencies F
. General Principle s o

f Operationa l Radiatio n Protectio n Introductio n Protectio n standard s Limits Reference levels Operationa l optimizatio n G
. Applicatio n t o th e Different Type s o f Exposur e Occupationa l exposure Conditions of

work Provisions

for restricting exposure Monitoring of

exposure The use of protection standards to interpret monitoring results Medical surveillance Intervention in abnormal

situations Medica l exposure Examinations or

treatments directly associated with illness Systematic examinations Examinations

for occupational, medico-legal or insurance purposes Medical research The optimization of

exposure Professional

training Othe r exposure s The assessment

of exposure The restriction of

exposure The release of

radioactive materials into the environment Direct external exposure from sources used

for industrial, medical or scientific purposes 8 7 9 1 9 4 9 6 10 3 11 3 11 5 11 6 11 7 12 9 11 3 13 6 13 6 14 4 14 5 14 9 15 3 16 0 16 0 16 1 16 7 17 3 17 5 18 4 18 8 19 5 19 7 20 0 20 2 20 3 20 5 20 8 21 0 21 2 22 0 22 0 22 8 Ths use of prod Practices raisin,: Tice use of

rad ic Monimrmg of

exp Monitoring in n Mwzitoring in a Intervention Appendix Rula. governing tl Membership Method of work Relationships with Financial support Publication s o

f th e Co ; Inde xP. 7

t p
'.its

capacity public

?nng results

llness

-ance purposes

• i.< -fi*. . nmenL , ' ! is trial, •- : '' .

• • ' • * ' - 

# i (

8 7 * 9 1 9 4 9 6 10 3 j 11 3 / 11 5 ^ 11 6 11 7 12 9 j 11 3 I 13 6 / 13 6 * 14 4 l 14 5 ( 14 9 j 15 3 / 16 0 16 0 16 1 167 17 3 17 5 18 4 18 8 19 5 197 20 0 / 20 2 / 20 3 ] 20 5 / 20 8 1 21 0 S 21 2 / 22 0 / 22 0 22 8 / ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^

1 

### 1

' RECOMMENDATION S O F TH E ICR P * 1 The use of products widely distributed to the public Practices raising the level of exposure to natural

background jThe use of radiation sources in teaching Monitoring of

exposure
' Monitoring in normal conditions Monitoring in abnormal circumstances Intervention Appendi x ^ Rules governing the selection and work ofthe Commission Membership Method of work Relationships with other bodies i Financial

support Publication s o f

th e Commissio n Inde x 

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### A . INTRODUCTIO N (1 ) Th e Internationa l Commissio n o n Radiologica

l Protectio n ha s been functionin g sinc e 1928 , when i t

wa s establishe db y th e SecondInternationa l Congres s of Radiology
. I t assume dit s present

organizationa l for

min 1950 in orde r

t o cove r more effectivel

y th e rapidl y expandin g fiel do f radiatio n protec
tion
. A s on e of

th e commission s establishe d b y th e Internationa l Congres s o f Radiology , ICRP ha s continue dit s clos e relationshi p wit h succeeding Congresses , an di t ha s als o been looke dt o a s th e appropriat e body t o give genera l guidanc e o n th e more widespreadus e o f radiatio n source s cause db y th e rapi d development s in th e fieldo f nuclea r energy . The Commissio n continue s t o maintai n it s traditional contac t

wit h medica l radiolog y an dth e medica

l professio n generally , an di t als o recognize s it s responsibilit y t o othe r pro fessiona l group s an dit s obligatio n t o provid e guidanc e withi n th e fieldof radiatio n protec
tio n a s awhole
. Detail s of

th e Commission' s rules , membership an d relationship s wit h other bodie s ar e t o b e foun di

n th e appendi x t o thi s report
. (2 ) Th e firs t recommendation s o f

th e ICR P wer e publishe din T928 , an dfurther report s wer e issuedi n 1931 , 193 4 arid 1937
. Followin g th e Commission' s reorganizatio n i n 1950 , basi c recommendation s wer e issue di n 1951 , 1955 an d1959
. A lis t

o f thes e an dothe r recommendation s o f

ICR P i s given i n th e appendi x t o thi s report
. (3 ) I n 196 6 th e Commissio n publishe dit s recommendation s (ICRPPublication 9) whic h ha dbeen adopte di

n 1965 ; the y wer

e amende di

n 196 9 ari d 1971
. Durin g th e las t decade ne w informatio n ha s emerge dwhich ha s necessitatedarevie w of theCommission' s basi c recommendations ; th e presen t report result s fro

mth e examinatio n o f

suc h ne w informatio n by th e Commissio n an dit s com mittee s an dtas k

groups . Th e recommenda

tion s mad e in thi s repor t

supersed e th e former basi c recommendation s publishe db y th e Commission , bu t

no t necessaril y thos e o f

it s committees * Althoug h thi s publicatio n comprise s acomprehensiv e revie w o f it s recom mendations , reference s ar e mad e in i t t o othe r report s o f ICR P committee s an dtas k groups , i n whic h more detaile ddiscussio n o f variou s point s ma y b e found
. (4 ) A s i n it s previou s recommendations , th e Commissio n deal s i n thi s report wit h ionizin g radiation s only
. Althoug h th e Commissio n recognize s that

adequat e contro l shoul db e establishe dove

r anumbe r of source s of

non ionizin g radiations , i t

continue s t o consider tha t thi s i s asubjec t

tha t lie s outsid e it s fieldo

f work
. (5 ) Th e Commissio n wishe s t o reiterat e tha t it s polic y i s t o consider th e fundamental principles.upo n whic

h appropriat e radiatio n protectio n measure s can b e based
. Becaus e o f th e differin g condition s tha t appl y i n variou s countries , detaile dguidanc e o n th e applica

tio n of it s recommendations , either i n regula

tion s o r in code s o f

practice , shoul d b e elaborate db

y th e variou s internationa l an d nationa l bodie s tha t

ar e familia

r wit h wha t i s bes t for thei r needs
. Th e Commissio n recog nize s tha t th e individual expert s responsibl e fo r puttin g radiatio n protectio n int o practic e nee dguidanc e tha t

i s sufficiently flexibl e t o allo w fo r national , regional o r

othe r variation
. Fo r thi s reaso n th e Commission' s recom mendation s ar e intende dt o provid e an appro priat e degre e o

f flexibility
. Becaus e o f

this , •Th e statu s o f

th e variou s committe e publication s i s show n in th e appendi x t o thi s report .P. 9

RECOMMENDATION S O F TH E ICRP th e for mi n whic h th e recommendation s ar e worde dwil

l no t necessarily b e suitable , an d ma y ofte n b e inappropriate , for direc t assimil

atio n int o regulation s o r

code s of practice
. General guidanc e o n th e applicatio n of th e Commission' s recommendation s i s give n i n section s F an d G
.



### B . OBJECTIVE S O F RADIATIO N PROTECTIO N (6 ) Radiatio n protectio n i s concerne dwit h th e protectio n of

individuals , their

progeny an dmankin da s awhole , whil e still allowin g necessar y activitie s fromwhic

h radiatio n exposure might

result
. Th e detrimenta l effect s agains t

which protectio n i s require d ar e know n a s somati c an dhereditary ; radia

tio n effect s ar e calle d"somatic " i f they become manifes t

in th e expose dindividual himself , an d"hereditary " i

f the y affec t hi s descendants
. (7 ) "Stochastic " effect s ar e thos e for which th e probability of

a n effect occurring , rathe r than it s severity , i s regarde da s afunctio n o f dose , withou t

threshold
. "Non-stochastic " effect s ar e thos e fo

r which th e severit

y of th e effect varie s wit

h th e dose , an dfor

which a threshol dma

y therefor e occur . At

th e dos e rang e involve di n radiatio n protection , heredi

tar y effect s ar e regarde da s bein g stochastic
. Som e somati c effect s ar e stochastic ; o f these , carcinogenesi s i s considere dt o b e th e chie f somati c ris k

o f irradiatio n at

lo w dose s an d therefore th e mai n proble mi n radiatio n protection
. (8 ) Som e non-stochasti c somati c effect s ar e specifi c t o particular

tissues , a s i

n th e cas e of catarac t ofth e lens , non-malignan t damag e t o th e skin , cel

l depletio n in th e bone-marro w causin g haematological deficiencies , an d gonadal cel

l damag e leadin g t o impairment o f fertility
. Othe r

non-stochasti c effect s ma y aris e i n th e blood-vessel s o r connectiv e tissu e element s which ar e commo n t o mos t organ s of th e body , an dtherefor e require that , a s a precautionary measure , adose-equivalent limi t shoul dappl y for

al l bod y tissues , t o en sur e tha t non-stochasti c effect s d o no t occur in any suc h tissue
. Fo r

al l thes e changes , th e severit y o f th e effect depend s o n th e magni

tud e ofthedos e received , an dther e i s likel y t o b e aclea r threshol dof

dos e belo w which n o detrimenta l effect s ar e seen . (9 ) Th e aimo

f radiatio n protectio n shoul d b e t o prevent

detrimenta l non-stochasti c effect s an dt o limit

th e probability of

stochas

ti c effect s t o level s deeme dt o b e acceptable
. An additiona l ai mi s t o ensur e tha t practice s involvin g radiatio n exposur e ar e justifie d(se e paragrap h 1 2 an dsection s E an dF)
. (10) Th e preventio n of non-stochasti c effect s woul db e achieve dby settin g dose

equivalent limit s a t sufficiently low value s s o tha t n o threshol ddos e woul db e reached , eve n followin g exposure fo r

th e whol e o f

alifetime or for th e tota l perio do f

workin g life
. Th e limitatio n of

stochasti c effect s i s achieve dby keepin g al l justifiabl e exposure s a s low a s i s reasonabl y achievable , economi c an dsocia l factor s bein g take n int o account , subjec t alway s t o th e boundary conditio n tha t th e appropriat e dose-equivalent limit s shal l no t b e exceeded(se

e paragraph s 103-128)
. (11 ) Mos t decision s abou t

huma n activitie s areibase d o n a

n implici t for mo f balancin g o

f cost s an dbenefit s leadin g t o th e conclusio n that ike conduc t

o f achose n practic e i s "worthwhile"
. Les s generally , i t i s als o recognize dtha t

th e conduc t

o f th e chose n practic e shoul db e adjuste dt o maximiz e th e benefit * o th e individual o r

t o society
. I n radiatio n protection , i t

i s becomin g possibl e t o formaliz e thes e broa ddecision-makin g procedures , thoug h no t

alway s t o quantif

y them
. Th e procedure s ar e detai l in sectio n E
. Howev c o f thes e procedure s doe s n sufficien t protectio n fo

r t h therefor e necessa-y . fo

r t h establis h dose-equivalen t

l i wher e th e benefit s an dd

i receivedby th e same i population
. (12) Fo r th e abov e rea s on ; recommend s asystemo

f d < mai n feature s of

whic h are a (a) n o practic e shal l b e i introductio n produc e benefit ; (b ) al l exposure s shal l b reasonabl y achievab l socia l factor s bein g t a an d (c ) th e dos e equivalen t

tc no t exceedth e limit s i th e appropriat e circu Commission
.

Detriment (15 ) Th e deleteriou s sffe t radiatio n ma

y b e of man y \ effect s o n health ther e ma

y t an dnon-stochasti c effect s i r vidua ! an dstochasti c effeci tions
. I n addition , ther e m effect s no t

associate dwit

h h needt o restric t

th e us e o products
. (16 ) Th e Commissio n h

£ concep t o f detrimen t

t o id t possibl e t o quantify , al l effects
. I n general , th e detri tio n i s define da s th e mathe i tion " o f th e har mincurre d\ t o radiation , takin g int o ac e probability of

each typ e of

c •International Commissio n o n Report 19, International Commiss :

# m 

# 1

ic e o n th e applicatio n o f th e recommendation s i s give

n in



### ROTECTIO N
tochasti c effect s d o no t

occur sue . Fo r al l thes e changes , th e effec t depend s o n th e magni

j received , an dthere i s likel y t o ;hol do f dos e belo w whic

h n o jet s ar e seen . } f radiatio n protectio n shoul d : detrimenta

l non-stochasti c mi tth e probability of

stochas

vel s deeme dt o b e acceptable , ai mi s t o ensure tha t

practice s tio n exposure ar e justifie d(see i d section s E an dF)
. reventio n o f

non-stochasti c b e achieve db

y settin g dose

t s a t sufficiently lo

w value s s o I ddos e woul db e reached , eve n sur e for th e whol e o

f alifetim e I perio do f workin g life
. Th e ochasti c effect s i s achieve db y ufiabl e exposure s a s lo

w a s i s ievable , economi c an dsocia l take n int o account , subjec t boundary conditio n tha t

th e se-equivalent

limit s shal l no t : paragraph s 103-128)
. vision s abou t

human activitie s implici t for mof balancin g of fits leadin g t o th e conclusio n tct of achose n practic e i s Les s generally , i t

i s als o t th e conduc t

of th e chosen b e adjuste dt o maximiz e th e individua l o r t o society
. In ction , i t i s becomin g possibl e hes e broa ddecision-makin g jug h no t alway s t o quantif

y RECOMMENDATION S O F TH E ICR P

them
. Th e procedure s ar e discusse di n mor e detai l in sectio n E
. However , th e applicatio n o f thes e procedure s doe s no t alway s provid e sufficien t protectio n for

th e individual
. I t

i s therefore necessary , for

thi s reaso n also , t o establis h dose-equivalent

limit s i n situation s wher e th e benefit s an ddetriment s ar e no t receivedb y th e sam e member s of th e population
. (12 ) Fo r th e abov e reasons , th e Commissio n recommend s asyste

mof dos e limitation , th e main feature s o

f which ar e a s follows : (a ) n o practic e shal l b e adopte dunles s it s introductio n produce s apositiv e ne t benefit ; (b ) al l exposure s shal l b e kep t a s lo w a s reasonabl y achievable , economi c an d socia l factor s bein g take n int o account ; an d (c ) th e dos e equivalen t

t o individual s shal l no t exceedth e limit s recommende dfo r th e appropriat e circumstance s b y th e Commission
. (13 ) I n applyin g thes e recommendations , i t mus t b e recognize dtha t

man y presen t prac tice s give ris e t o dos e equivalent s tha t wil l b e receivedi n th e future
. Thes e dose-equivalen t commitment s (see paragrap h 25 ) shoul db e take n int o accoun t

s o tha t necessar y develop

ment s o f presen t or futur e practic e woul dno t b e liabl e t o resul t

i n undu e exposur e of

an y member s o

f th e public
. (14 ) Althoug h th e principal objectiv e o f radiatio n protectio n i s th e achievement an d maintenanc e of

appropriatel y saf

e condition s fo r activitie s involvin g human exposure , th e leve l of safet y require dfor

th e protectio n o

f al l human individual s i s though t likel y t o b e adequat e t o protec t

othe r species , althoug h no t necessarily individual member s o f thos e species
. Th e Commissio n therefor e believe s tha t i f ma n i s adequatel y protecte dthe n othei * living thing s ar e als o likely t o b e sufficiently protected
.



### C . BASI C CONCEPT S Detriment (15 ) Th e deleteriou s effect s o f exposure t o radiatio n ma

y b e o f man y kinds
. Amon g th e effects o n healt

h there ma

y b e bot h stochasti c andnon-stochasti c effect s i n th e expose dindi

vidua l an dstochasti c effect s in later genera tions
. I n addition , ther e ma y b e deleteriou s effects no t associate dwit

h health , suc h a s th e nee dt o restric t

th e us e of

som e area s o r products
. (16 ) Th e Commissio n ha s introduce dth e concep t of detrimen t

t o identify , an dwher

e possibl e t o quantify , al l thes e deleteriou s effects
. I n general , th e detrimen t in apopula

tio n i s define da s th e mathematical "expecta

tion " of th e har mincurre dfro

ma n exposure to radiation , takin g int o accoun t no t only th e probabilit y o f eac h typ e o

f deleteriou s effect , bu t

als o th e severit

y of th e effect
. Thes e deleteriou s effect s includ e both th e effect s o n healt h an dothe r

effects
. On som

e occasion s i

t i s convenient

t o deal separatel y wit

h th e effects , o r th e potentia l effects , o n health
. Thes e ar e the n characterize db

y th e concep t

o f detrimen t t o health
. Fo r

effect s o n health , i

f p it th e probability o

f sufferin g th e effect

/ , i s smal l an dth e severit

y of th e effect i s expresse d b y aweightin g facto r

g „ the n th e detrimen t

t o health , G , i

n agrou p of

Pperson s i s give

n b y G=P]T

l Pig i
Dose equivalent (17 ) Th e absorbe ddose, * D, i s insufficient b y itself t o predic t

eithe r th e severit

y o r th e •Internationa l Commissio n o n Radiatio n Unit s an dMeasurements , Radiatio n Quantitie s an dUnits , ICRU Report /9 , Internationa l Commissio n o n Radiatio n Unit s an dMeasurements , Washington , 1971
.P.1 1

RECOMMENDATION

S O F TH E ICR P probability of

th e deleteriou s effect s on healt h resultin g fro mirradiatio n unde r unspecifie d conditions
. In radiatio n protectio n i t ha s bee n foun dconvenient

t o introduc e afurther quantity tha t

correlate s bette r

wit h th e more importan t deleteriou s effect s of

exposure t o radiation , more particularl y wit h th e delaye d stochasti c effects
. Thi s quantity , calle ddos e equivalent , i s th e absorbe ddos e weighte db y th e modifyin g factor s Q an dT V give n i n paragraph s 18-20
. (18 ) Th e dos e equivalent , H, a t apoin t in tissue , i s given by th e equatio n

H = DQN wher e D i s th e absorbe ddose , Q i s th e qualit y facto r an dN\s th e produc t

o f al l othe r modi

fyin g factor s specifie db

y th e Commission
. Such factor s migh

t tak e account , for

example , o f absorbe ddos e rat e an dfractionation
. A t present , th e Commissio n ha s assigne dth e valu e 1 t o N. Th e specia

l name for th e uni t of dos e equivalen t

i s th e siever

t (Sv ) lS v = Ukg-'^lOOrem)
. (19 ) Th e quality factor , Q, i s intende dt o allo w for th e effec t

o n th e detrimen t

o f th e microscopi c distributio n o f absorbe denergy . It i s define da s afunctio n ofth e collisio n stop
pin g powe

r (Ioo ) in water

a t th e poin t

of interest
. Interpolate dvalue s of Q a s a functio n of

Lm can b e obtaine dfromth e figure , which i s base do n th e value s show n i n th e table
. Lx-Q RELATIONSHI P L-c i n wate r (keV/fim ) 3.5 (an d less ) 7 2 3 5 3 17 5 (an d above ) 0

1 2 5 1 0 2 0 Fo r aspectru mof

radiation , an effectiv e value , Q, of

Q a t th e poin t of interes t ca n b e calculated. * (20) Whe n th e distributio n of radiatio n in La,, i s no t know n a t al l point s i n th e volum e o f interest , i t i s permissibl e t o us e approximat e

o



### o 2 0

1 5 -

1 0 I I I I I I T 1 I I I I I | ~l 1 IIII I

' ' ' ' IIII I J ' i i i i i i IO 3 Collisio n stoppin g powe ri n water , keV//i m FIG . 1 . Qualit

y facto r a s a function o f

collisio n stoppin g power i n water. •Internationa

l Commissio

n o n .Radiatio

n Unit s an d Measurements, Dos e Equivalent , Supplement

lo ICRU Report 19, Internationa

l Commissio

n o n Radiatio n Unit s an d Measurements, Washington, 1973 . value s fo r Q relate dt o th

< primar y radiation
. Fo r

thi s mission recommend s th e f Q t o b e use dfo

r both ex t radiation : X rays , y ray

s an d electron s Neutrons , proton

s an d singly-charge

d particle s o f i greate r tha n on e atomi c m a unknow n energ y a particle s an d multiply-ch ; particle s (an d particleso

f u: charge) , o f

unknow n cnerg ; I n th e cas e of

thermaln t uniquel y defined , an dQ r r th e table s an ddiagram s w h functio n o f

neutro n e

m Publication 21, fig
. 15 , g i therma l neutrons)
. (21 ) Th e recommende d\ are intende dfor

us e onl y ir
. tion , an dthe n for

compari exposure wit

h th e limit s o

f c for assessin g thos e compo r that ar e take n int o aecou n suc h limits
. Th e value s of

C selectedo n th e basi s o f

rele\ tiv e biological effectivenes s accoun t o f th e fac t tha t t h limit s (se e paragraph s 103

- extrapolation s fromhigher whic h deleteriou s effect s i

n l y assessed
. Thes e value s c no t necessarily represent a relativ e biological effect i observe deffects , suc h a s s t animal s a t low level s of

abs c stochasti c effect s in ma

n doses
. I t i s particularl y i

m equivalent shoul dno t

b e i likel y earl y consequence s o . exposure s i n man . Collective dose equivalent (22) Th e relationshi p b an dth e distributio n of

do s expose dpopulatio n i s n o single quantit y can adequ aP.1 2

alit y factor , Q, i s intende dt o effect o n th e detrimen t

o f th e stributio n of

absorbe denergy , afunctio n of

th e collisio n stop
La, ) i n wate r

at th e poin t

o f rpolate dvalue s of

Q a s a .ai can b e obtaine dfromth e s base do n th e value s show n in

. X -Q RELATIONSHI P Lv i n wate r (keV/Mm ) an d less )
(an d above ) 0

1 2 5 1 0 2 0 i mo f radiation , an effectiv e ) a t th e poin t of interes t can b e h e distributio n of

radiatio n in v n a t al l point s in th e volume of jermissibl e t o us e approximat e

T— I IIII I


### /

' ' i i i i i i IO 3 ter , keV//i m g powe r in water .

os e Equivalent , Supplement to ICRU

. , Washington ; .lV73 , RECOMMENDATION S O F TH E ICR P value s for Q relate dt o th e variou s type s o f primar y radiation
. Fo r

thi s purpos e th e Com

mission recommend s th e following value s o f O t o b e usedfor

both externa

l an dinterna l radiation : X rays , y ray s an d electron s 1 Neutrons , proton s an d singly-charge d particle s o f res tmas s greate r tha n on e atomi c mas s uni to f unknow n energy 1 0 a particle s an d multiply-charge d particle s (an d particle s o f unknow n charge) , o f

unknow n energy 2 0 I n th e cas e o f

thermal ^ neutron s th e La, i s uniquel y defined , an dQ ma y b e takenjro m th e table s an ddiagram s which presen t Q a s a functio n of

neutro n energ y -{viz. ICRP Publication 21, fig
. 13 , givin g Q = 2. 3 for thermal neutrons)
. (21 ) Th e recommende dvalue s o f Q an dQ ar e intende dfor

us e onl y i n radiatio n protec
tion , an dthe n for

comparin g actual level s o f exposur e wit h th e limit s o

f dos e equivalent , o r fo r assessin g thos e component s o f detrimen t tha t ar e take n int o accoun t

in th e settin g of suc h limits
. Th e value s o

f Q an dQ hav e bee n selectedon th e basi s of

relevant value s o f rela

tive biologica

l effectivenes s bu t

they als o tak e accoun t o f th e fact tha t th e dose-equivalent limit s (se e paragraph s 103-104 ) ar e base do n extrapolation s fro

mhighe r absorbe ddose s at whic h deleteriou s effect s imma

n ca n b e direct

l y assessed
. Thes e value s of Q are therefor e no t necessarily representativ e o f value s o f relativ e biologica

l effectivenes s for

othe r observe deffects , suc h a s stochasti c effect s i n animal s a t low level s o f

absorbe ddos e o r

non stochasti c effect s in ma

n a t hig h absorbe d doses
. It i s particularl y importan t

tha t dos e equivalent shoul dno t

b e usedt o asses s th e likel y early consequence s of

sever e accidenta l exposure s i

n man . Collective dose equivalent (22) Th e relationshi p between detrimen t an dth e distributio n of

dos e equivalen t

in a n exposedpopulatio n i s no t simple , an dh o single quantity ca

n adequatel y represen t

th e distributio n for

th e purpos e o

f assessin g detri

ment
. Nevertheless , ther e ar e man y situation s in whic h valuabl e us e can b e mad e of th e quantit y calle dcollectiv e dos e equivalent
. Th e collectiv e dos e equivalen t (S ) i n apopula

tio n i s define db

y th e expressio n 

### S=ll,H,P, where // , i s th e per

caput dos e equivalen t

in th e whol e bod y o r

any specifie dorga n or tissu e of th e Pt member s of

sub grou p (/'

) of th e expose dpopulation
. Th e applicatio n o f thi s concep t

i s discusse di n paragraph s 219 , 22 1 an d 232
. (23 ) Th e collectiv e dos e equivalen t (Sk) fro mapractic e o r

sourc e (k), i s define dby th e expressio n 

# H : HP(H)dH where P{H) dH

i s th e numbe r

of individual s receivin g ados e equivalen t in th e whol e body o r an y specifie dorgan o r

tissu e i n th e rang e H toH+ dH. I t

i s ofte n no t

necessar y t o asses s th e contribution s fro msmal l value s of H accurately , provide dtha t a n uppe r estimat e show s tha t

the y woul dno t

ad dsignificantl y t o th e tota l integral
. Ordinarily , th e uppe r rang e of th e integratio n i s limite db y th e relevan t dose-equivalen t

limits
. A collectiv e dos e equivalen t

includin g contribution s fromhig h dose s i s no t

suitabl e for

assessment s o f

th e typ e describe din paragrap h 24
. (24 ) In th e definitio n o f

th e detrimen t

t o healt h (paragrap h 16) , i

f there i s aproportional relationshi p betwee n H

an d /? , (se e paragraph s 27-30 ) an di

f g t i s independen t

o f H, the n th e detrimen t t o health , G, i s proportiona l t o th e collectiv e dos e equivalent , Sk. Th e validit y o f thi s relationshi p betwee n detrimen t an dcollectiv e dos e equivalen t depend s o n th e validity o f

th e assume dlinearity , wit h n o threshold , betwee n ris k an ddos e equiva

lent
. Th e Commissio n ha s stresse dtha t thi s i s acautiou s assumption , th e reliabilit y o f which ha s no t yet been established , an di t i s conceivabl e tha t

th e proportionalit y factor sP.1 3

RECOMMENDATION S O F THE ICR P o r ris k factor s (ris k

pe r uni t dos e equivalent ) coul d var y wit h th e previousl y accumulate d dos e equivalent
. However , fo r practice s resultin g i n smal l increment s o f dos e equivalen t

abov e tha t

correspondin g t o th e natura l background , th e additiona l detrimen t t o health , AC , fro mapractic e (k) mus t b e closel y proportiona l t o 5* , eve n thoug h th e proportionalit y constan t ma y b e unknown
. Furthermore , approximat e proportionalit y woul dhol di n case s wher e al l th e individua l dos e equivalent s fel l withi n aroughl y linea r regio n o f th e dose-respons e relationship
. Dose-equivalent

commitment (25 ) Furthe r

quantitie s ar e neede dwhe n th e exposur e i s extende di n time
. Th e dose

equivalen t

commitment , H c> fro magive n decisio n o r

practice , i s th e infinit e tim e in

tegra l o f th e per caput dose-equivalen t

rate , H(t), i n agive n orga n o r tissu e fo r

aspecifie d population : Th e expose dpopulatio n i s no t necessaril y constan t i n number
. I t

i s als o possibl e t o defin e acollectiv e dose-equivalen t commit

ment , whic h i s obtaine db y integratio n o f th e collectiv e dose-equivalen t rate
. Committed

dose equivalent (26 ) Anothe r

quantit y use di n thes e recom mendation s i s th e "committe ddos e equiva

lent" , //so , t o agive n orga n o r tissu e fro ma singl e intak e o f

radioactiv e materia l int o th e body
. Thi s quantity , whic h ma y b e considere d t o b e aspecia l cas e o f

dose-equivalen t

com mitment , i s th e dos e equivalen t tha t wil l b e accumulate dove r

5 0 years , representin g a workin g life , followin g th e intake :

f' o + 50 y H 50= \ H(t)dt J ' o 

# H ff(t) dt where//( 0 i s th e relevan t dose-equivalen t

rat e an dt0i s th e tim e o f

intake
.



### D . RADIOBIOLOGICA L CONSIDERATION S

DOSE-RESPONS E RELATIONSHIP S (27 ) Th e relationshi p betwee n th e dos e receive db y a n individua l an dan y particula r biologica l effec t

induce db y irradiatio n i s a comple x matte r

o n whic h muc h furthe r

wor k i s needed
. Fo r

radiatio n protectio n purpose s i t i s necessar y t o mak e certai n simplifyin g assumptions
. On e suc h basi c assumptio n underlyin g th e Commission' s recommenda

tion s i s that , regardin g stochasti c effects , ther e is , withi n th e rang e o f exposur e condi

tion s usuall y encountere di n radiatio n work , a linea r relationshi p withou t

threshol dbetwee n dos e an dth e probabilit y o f a n effect
. Th e simpl e summatio n o f

dose s receive db y a tissu e o r orga n a s ameasur e o f

th e tota l risk , an dth e calculatio n o f th e collectiv e dos e equivalen t

(se e paragraph s 2 2 an d23) , a s a n inde x o f th e tota l detrimen t

t o apopulation , ar e vali donl y o n th e basi s o f thi s assumptio n an dtha t th e severit y o f

eac h typ e o f

effec t i s independen t

o f dose
. (28 ) Th e adde dris k

fro magive n dos e incre

men t wil l depen do n th e slop e o f th e dose

respons e relationship
. I f th e dose-respons e relationshi p fo r

stochasti c processe s i s i n fac t highl y sigmoid , th e ris k

fro mlo w dose s coul d b e overestimate db y makin g alinea r extra
polatio n fro mdat aobtaine da t hig h doses
. Ther e ar e radiobiologica l

in g tha t th e dose-respon s radiatio n wil l generall y i r increasin g dos e an ddt absorbe ddos e rang e u p man y effect s studie dt respons e i n thi s rang e ca : a n expressio n o f

th e form : E = aD + wher e E denote s th e eff

c " A " an d"b"

ar e constr
. ter m(bD 2 ) i n thi s express ; hig h absorbe ddose s (g i gray ) an dhig h absorbe d orde r o f on e gra y pe r

r linea r ter m(aD) an dth e s k com e t o predominat e a s t h ar e reduced
. Althoug h a for mha s bee n documen t effects , th e relativ e value

- "a" an d"6 " var y fro m another
. Th e exten t

t o wh ma y diffe r

fo r othe r s i tu a determined
. Fo r

hum a particular , knowledg e o f • tionship s i s to o limite d u predictio n o f

th e shape s curve s a t lo w dose s an dlo v theless , i n afe w instance s r : base do n result s o f

irr a population s involvin g sin s ofth e orde r

o f 0. 5 G y o r

l e repeate da t

interval s o f

af e suc h case s i t

ca n b e reaso r th e frequenc y pe r

uni t abs c cula r harmfu l effect s re

< exposure s i s no t

likel y t o o

•Igray(Gy)=Ukg- | (=100r a tAt hig h dose s thi s expressio n •

• cel l sterilization
. Thi s effec

t i s n c see paragrap h 33. )populatio n i s no t

necessarily imber
. I t i s als o possibl e t o tiv e dose-equivalen t

commit

obtaine dby integratio n of th e equivalen t rate
.

se equivalent •quantit y use din thes e recom th e "committe ddos e equiva

i give n organ o r

tissu e froma f radioactiv e material int o th e ntity , whic h ma

y b e considere d cas e o f dose-equivalen t

com e dos e equivalen t

tha t wil l b e >ve r 5 0 years , representin g a blowin g th e intake : 

# -i : , + 30

y H(t) dt

: e relevan t dose-equivalen t

rat e e o f intake
.



### KRATION S HIP S

a s ameasur e o

f th e tota l risk , Iatio n of th e collectiv e dos e paragraph s 22 an d23) , a s a n ta l detrimen t

t o apopulation , m th e basi s o

f thi s assumptio n verit y o f eac h typ e o

f effect i s dose
. e drisk fromagive

n dos e incre

- :n d o n th e slop e of

th e dose

onship
. I f th e dose-respons e r stochasti c processe s i s i

n fac t

. th e ris k fromlo w dose s coul d e db y makin g alinea

r extra
dat aobtaine da

t hig h doses
. RECOMMENDATION S O F TH E ICR P

There ar e radiobiologica l ground s for assum ing tha t th e dose-respons e curv e for low-LE T radiatio n wil

l generall y increas e i n slop e wit h increasin g dos e an ddos e rate , ove r th e absorbe ddos e rang e u p t o afe w gray. * Fo r man y effect s studie dexperimentally , th e respons e i n thi s rang e can b e represente dby a n expressio n of

th e form : E = aD + bD 2 1 wher e E denote s th e effect , D th e dos e an d "a " an d"b"

ar e constants
. Th e quadrati c ter m(bD 2 ) i n thi s expressio n predominate s at hig h absorbe ddose s (generall y abov e on e gray ) an dhig h absorbed-dos e rate s (o f th e order of on e gra y pe r min) ; however , th e linea r ter m(aD) an dthe slop e tha

t i t represent s com e t o predominat e a s th e dos e an ddos e rat e are reduced
. Althoug h arelationshi p o f thi s

- for mha s been documente dfor avariet y of effects , th e relativ e value s of th e parameter s " A " an d"b"

var y fro mon e observatio n t o another
. Th e extent

t o which th e relationshi p ma y diffe r fo r othe r situation s remain s t o b e determined
. Fo r

human population s in particular , knowledg e o f

dose-respons e rela

tionship s i s to o limite dt o enabl e confiden t predictio n o

f th e shape s an dslope s o f th e curve s at lo w dose s an dlo

w dos e rates
. Never

theless , i n afe w instance s ris k

estimate s ca

n b e base do n result s o f

irradiatio n of

human population s involvin g singl e absorbe ddoses , o f th e orde r of 0. 5 G y o r less , o r t o suc h dose s repeate da t

interval s of

afe w day s o r more . In such case s i t

ca n b e reasonabl y assume dtha t th e frequenc y per

uni t absorbe ddos e of

parti

cula r harmfu l effect s resultin g fro msuc h exposure s i s no t

likely t o overestimat e greatl y th e frequenc y of suc h effect s in th e dos e rang e of concer n in radiatio n protection , eve n thoug h th e latte r

ma y b e receive da t

muc h lowe r dos e rates
. (29 ) I n man y instances , however , ris k estimate s depen do n dat aderive dfrom irradiatio n involvin g higher dose s delivere da t high dos e rates
. I n thes e cases , i t i s likely tha t th e frequenc y of

effect s pe

r uni t dos e wil l b e lowe r followin g exposure t o low dose s o r t o dose s delivere da t

lo w dos e rates , an di

t ma y b e appropriate , therefore , t o reduc e thes e estimate s by afacto r

t o allo w for

th e probabl e differenc e in risk
. Th e ris k factor s discusse d late r hav e therefor e bee n chose n a s fa r a s possibl e t o appl y in practic e fo r th e purpose s o f radiatio n protection
. (30 ) Th e us e of

linea r extrapolations , fro m th e frequenc y o f

effect s observe da t

hig h doses , ma y suffic e t o asses s a n uppe r limi t o f risk , wit h whic h th e benefi t

of apractice , or th e hazar dof

an alternativ e practice—not : involvin g radiatio n exposure—ma y b e compared
. However , th e more cautiou s suc h an assumptio n of

linearit y is , th e more importan t i t become s t o recogniz e tha t i t ma y lea dt o a n overestimat e o f

th e radiatio n risks , which i n tur n coul dresul t in th e choic e o

f alternative s tha t

ar e mor e hazardou s tha n practice s involvin g radiatio n exposures . Thus , in th e choic e o f

alternativ e practices , radiatio n ris k

estimate s shoul db e use donly wit h great cautio n an dwit

h explici t recognitio n of

th e possibilit

y tha t th e actua l ris k a t low dose s ma

y b e lowe

r tha n tha t implie db y adeliberatel y cautiou s assumptio n o f proportionality
.

• l gra y (Gy ) = I Jkg- 1 ( = 10 0 rad)

. tA t hig h dose s ihi s expressio n woul dhav e t o b e modifie dt o tak e accoun t o f th e decrease dtumou r

ris k cause db y cel l sterilization
. Thi s effec t i s no t significan t

a t th e dose s encountere di n norma l exposur e conditions
. (However , se e paragrap h 33. )RECOMMENDATION S O F TH E ICR P P.1 5

IMPLICATION S O F ASSUMPTION S ABOU T DOSE-RESPONS E RELATION S (31 ) A practica l radiatio n protectio n syste mneed s t o b e base do n certai n simplify

ing assumption s i

f i t i s t o b e applie deffec

tively
. Th e assumption s already mad e abou t th e proportionalit y between dos e an deffect ove r th e rang e of

dose s of

concer n in radiatio n protectio n imply certai n principle s tha t can b e applie dt o importan t practica l problem s suc h a s thos e relatin g t o significant volume s an darea s an dth e rat e a t which dose s ma y b e accumulated
. Thes e ar e dis

cusse din th e paragraph s tha t follow
. Significant

volumes and

areas (32) Fro mth e assumptio n abou t th e proportionalit y between dos e an drespons e (se e paragraph s 27-30 ) i

t woul dfollo w tha t for stochasti c effect s i t

woul db e justifiabl e t o consider

th e mea n dose * ove

r al l cell s o

f unifor msensitivit

y in aparticula

r tissu e o r organ . Thi s us e o f

th e mea

n dos e ha s practical advantage s in tha t th e significant volume can usuall y b e take n a s tha t of th e organ o r tissu e unde r

consideration
. (33 ) Whe n th e irradiatio n o f atissu e i s non-homogeneous , th e us e o f th e mea n dos e ove r th e tissu e cease s t o b e strictl y vali di f dose s t o individual cell s diffe r more widel

y than th e rang e o f

dose s ove r which th e dose

respons e relationshi p for

th e tissu e ca

n b e regarde da s linear
. A n exampl e of thi s ma y b e th e irradiatio n o f

th e lun g by radioactiv e particulates
. However , o n th e basi s of theoretical considerations , an do f availabl e epidemiological evidence , th e Commissio n believe s that , fo r

lat e stochasti c effects , th e absorptio n of

agiven quantit y o

f radiatio n energ y i s ordinaril y likel

y t o b e les s effectiv e whe n du e t o aserie s of

"ho t spots " tha n whe n uniforml y distributed , becaus e of th e effect

of high dose s in causin g th e los s of reproductiv e capacity o r

th e deat h of cells
. Thus , wit h particulat e radioactiv e source s withi n atissue , t o asses s th e risk b y assumin g ahomogeneou s dos e distributio n woul d probabl y overestimat e th e actua l risk
. Moreover , for

non-stochasti c effects , th e limite damoun t

o f cell los s tha t

migh t resul t a t moderat e dos e level s woul db e mos t unlikel y t o caus e an y impairmen t o f organ function
. (34 ) Fo r exposur e o f

th e skin , either

t o external source s o r

a s aresul t

o f ski n contamination , i t

i s no t generall y appro priat e t o averag e th e dos e equivalen t ove r th e entire skin
. Th e averagin g procedur e wil l depen do n th e circumstance s an di s discusse d in more detai l i n paragraph s 182 an d183
. Rate of dose accumulation (35 ) Th e Commissio n previousl y recom mende dthat , fo r

occupationa l exposure , th e magnitud e of

asingl e dos e equivalen t

shoul d b e limite dt o one-hal f

o f th e former

annua l dose-equivalen t

limit
. Thi s practice , whic h wa s intende dt o preven t

th e accumulatio n of more tha n th e annua l dose-equivalen t limit withi n ashort

perio do f time , no w seem s t o b e unnecessary . Th e Commissio n therefore believe s tha t

i t i s sufficient

t o se t annua l dose-equivalent

limit s an ddoe s no t recommen dan y furthe r

restriction s either

o n th e instantaneou s rat e o r

o n th e rat e at

which th e dos e equivalen t

ma y b e accumulated , except i n th e cas e o f

occupationa l exposure o f women o f

reproductiv e capacit

y an d pregnan t wome n (se e paragraph s 11 5 an d 116)
. I n consequence , th e Commissio n n o longe r recommend s th e us e of th e forme

r age-relate dformula
. 'Unles s specificall y qualified , th e ter m dos e equivalen trefer s t o th e mea n dos e equivalen tove r th e entir e orga n o r tissue . (36 ) I mit s forme r

re c Commissio n state dthat
. on e orga n o f

the bod ; irradiatio n o f

on e partic t i s likel y t o b e o f

greates t i o f th e dos e i t

receives , radiatio n o r

th e importa

n damag e tiia t

results. Thi s referre dt o a s th

e criti c circumstances , an ddos e individua l wa s determi r equivalen t

limi t fo r tha t t • concep t o f itBc e critical or

g di dno t permi t the sum m accordin g tt

o th e relativ e r th e irradiate dtissues
. Th

< recommend s aproced ; accoun t o f ttfoe tota l risk exposum e o f al l tissu e paragrapfc s 104,10 5 an d1 (37 ) F«n r th e purp o protectMH mi k i s necessar

y t

. o f organ s ami

d tissue s th

r sidere d toecannse o

f the r radiaitiamn damage , th e s t damag e ami

d tb e extent

t o \ treatalbfte
. I n thi s sectio n present s a n outlin e o

f th e abou t ttflnesE feature s fo

r radiatiknmprotection
. (38 ) Ssmms e o f th e quan t discusse diro

n th e followi

r clearl y age - «n

r sex-depend

t thos e ffunr ttBae developmen o r fo r aSa e inductio n of

he r additiiHm , ttSn e tris k factor s o f nialliipnMgBE

S are reduce becaansetrnffttlii

e long latent ; th e ckwdktsipminen

t o f thes e reason s ttlla

e tota l ris k

f r expoKnnn e wifl l war y some w wit h SEE , aEttboug

h in h fro mHBD

E awanage valu e fo : sexe s as e mast

considerab ! purpose s tffinerefore

, suff i > y rasing asingXP S ABOU T N S '. 1 dose s in causin g th e los s o f capacit y or th e deat h of cells , particulate radioactiv e source s ; , t o asses s th e ris k

by assumin g ou s dos e distributio n woul d erestimate th e actua l risk
. or non-stochasti c effects , th e nt o f cell los s tha t

migh t result dos e level s woul db e mos t aus e any impairmen t

o f organ xposur e of th e skin , eithe

r t o ree s o r a s aresul t

o f ski n n , i t i s no t generally appro ag e th e dos e equivalent

ove r th e Th e averagin g procedur e wil l e circumstance s an di s discusse d

. 1 in paragraph s 18

2 an d183
. ? accumulation Commission previously recom for occupational exposure , th e \ asingl e dos e equivalent

shoul d one-hal f o f th e forme

r annua l ;n t limit
. Thi s practice , whic h t o prevent th e accumulation-o f i e annua l dose-equivalent

limi t t perio do f time , now seems t o ry . Th e Commissio n therefore i t i s sufficien

t t o se t annua l ;n t limit s an ddoe s no t tn y further restrictions either

o n ecu s rat e or

o n th e rat e a t

which iiivalen t ma y b e accumulated , cas e o f occupational exposure o f reproductiv e capacit

y an d me n (see paragraph s 11 5 an d sequence , th e Commissio n n o amend s th e us e o

f th e forme

r )rmula
. clos e equivalen tove r ih e entir e organ,o r RECOMMENDATION S O F TH E ICR P TISSUE S A T RIS K (36 ) I n it s forme

r recommendation s th e Commissio n state dthat , whe n more tha n on e orga n o f th e body i s exposed , th e irradiatio n o

f on e particular

orga n o r tissu e i s likel y t o b e o f greates t importanc e becaus e o f th e dos e i t

receives , it s sensitivit

y t o radiatio n o r

the.importancet o healt

h o f any damag e tha t

results
. Thistissu e o r

organ wa s referre dt o a s '.th

e critical on e under

th e circumstances , an ddos e limitatio n fo r th e individua l wa s determine db

y th e dose

equivalen t limi t fo r tha t tissu e o r organ . Th e concept o f th e critical orga

n usedin thi s wa

y di dno t permi t th e summatio n of

detrimen t according t o th e relativ e radiosensitivitie s o f th e irradiate dtissues
. Th e Commissio n no w recommend s aprocedur e whic h take s accoun t of th e tota l :risk

attributabl e t o th e exposur e o f al l 'tissue s irradiate d(see paragraph s 104,10 5 an d125)
. (37 ) Fo r th e purpose s o

f radiatio n protectio n i

t i s necessar

y t o specif y anumber o f organ s an dtissue s that

hav e t o b e con sidere dbecaus e o

f their susceptibilit

y t o radiatio n damage , th e seriousnes s of suc h damag e an dth e extent

t o whic h thi s coul db e treatable
. In thi s sectio n th e Commissio n present s a n outlin e of

th e assumption s made about thes e feature s fo

r th e purpose s o

f radiatio n protection
. (38 ) Som e o f th e quantitativ e risk

factor s discussedin th e following paragraph s ar e clearl y age - o r sex-dependent , a s fo

r exampl e thos e fo r th e development

o f breas t cancer or for th e inductiono f

hereditar y defects
. In addition , th e ris k

factor s fo

r th e occurrenc e of malignancie s ar e reduce din olde r person s •becaus e o f th e long laten t

period s involve di

n th e development

o f thes e effects
. Fo r

thes e reason s th e tota l ris k

froma n individual exposur e wil l var y somewha t

wit h ag e an d wit h sex , althoug h i

n fact th e variation s fro mth e averag e valu e fo

r al l ages an dboth sate s ar e no t

considerable
. Fo

r protectio n purpose s therefore , ;sufficien t accurac y i s obtaine db

y using as'ingl

e dose-equivalen

t limit for eac h orga n o r

tissu e fo r al l worker s regardles s o f

ag e o r sex . Thes e limit s ar e base dupo n th e averag e ris k level s describe d belo w for th e variou s organ s o r

tissues
. Th e sam e principl e applie s als o fo r differen t member s o f

th e general public
. (39 ) Th e ris k

factor s fo r

differen t tissue s ar e base dupo n th e estimate dlikelihoo d of inducin g fatal malignan t disease , non stochasti c changes , o r

substantia l geneti c defect s expresse di n liveborn descendants
. I t i s recognize dtha t

th e appropriat e basi s fo r quantifyin g detrimen t

shoul d includ e di e evaluatio n of

al l othe r form s o f

hur t an d sufferin g tha t

ma y resul t fro mexposure . Thi s proble mi s th e subjec t o f atas k grou p report bein g prepare dfo r

th e Commission
. I t appear s likel y tha t

th e form s o f

detrimen t mentione dabov e woul db e regarde da s th e dominan t component s o f

th e har mtha t

ma y b e cause db y radiation , an dthos e o n whic h ris k factor s shoul dmos t

appropriatel y b e based
. Gonads (40 ) Deleteriou s effect s cause db y irradia

tio n o f th e gonad s ma

y b e o f thre e differen t types : tumou r

induction , impairmen t of fertilit y i n th e irradiated , individual , an d hereditar y effect s i n descendants
. (41 ) Huma n gonad s appea r t o hav e a relatively lo w sensitivit

y t o th e inductio n o

f cancer b y irradiation , sinc e n o carcinogeni c effect s i n thes e organ s hav e ye t bee n documente dconclusively
. (42 ) In th e female , impairmen t o f fertilit y varie s wit h age . Inductio n o f

menopause, wit h permanen t

cessatio n o f

fertility , coul d result fro ma n absorbe ddos e o f 3 G y (low

LET radiation ) in awoma n age d40 , wherea s th e same absorbe ddos e migh t caus e onl y temporary amenorrhoe ai n awoman age d 20
. Th e differenc e i s relate dt o th e fac t tha t productio n of

ne w oocyte s normall y cease s i n childhood , th e numbe r o f suc h cell s decreasin g progessivel y wit h ag e afterP.1 7

1 0 RECOMMENDATION S O F TH E ICRP menarche , a s oocyte s los t fro mth e ovar y throug h ovulatio n o r

fo r othe r cause s ar e no t replaced
. I n th e testis , b y contrast , th e suppl y o f

spermatozo ai s replenishe d continuall y throughou t

adul t lif e b y prolifer

atio n o f spermatogoni aan dothe r sper m precurso r cells
. Depletio n o f

suc h cell s b y irradiatio n ca n b e repaire di f enoug h spermatogoni aremai n intac t t o repopulat e th e damage dtestis
. Althoug h th e sper m coun t ma y b e depresse dtemporaril y b y a n absorbe ddos e o f

0.2 5 G y (low-LE T radia

tion ) delivere da t

ahig h dos e rate , th e absorbe ddos e require dt o caus e permanen t sterilit y i s large r

b y a t leas t a n orde r

o f magnitude
. (43 ) Th e gonad s ar e th e tissue s involve di n th e productio n o f

radiation-induce dgen e mutation s an dchromosoma l change s leadin g t o hereditar y defects
. Observations , mainl y o n smal l mammal s an dlowe r organisms , hav e provide ddat ao n th e frequencie s o f hereditar y change s resultin g fro mirradiation ; observa

tion s o n ma n hav e indicate dth e frequencie s o f th e variou s naturally-occurrin g hereditar y an dpartiall y hereditar y disease s tha t migh t b e affected
. Th e extent s t o whic h thes e disease s woul dincreas e with : agive n increas e i n th e mutatio n rat e havefo r

th e mos t par t no t bee n demonstrate d directl y i n an y organism
. I t i s believe dtha t

th e frequenc y o f

dominant , sex linke dan dcertai n chromosoma l disease s woul dincreas e i n direc t proportio n t o dose
. Th e increas e i n th e mor e commo n "irregularl y inherited' ' disease s woul db e less , especiall y i n th e firs t tw o generations
. Wher e th e whol e o f th e bod y i s expose duniformly , i t ha s bee n estimate dfo r

presen t purpose s tha t

th e hereditar y detrimen t

i s likel y t o b e les s tha n th e detrimen t

du e t o somati c injur y i n th e irradiate dindividuals
. Th e ris k o f seriou s hereditar y il l healt h withi n th e firs t tw o gener ation s followin g th e irradiatio n o f eithe r paren t i s take n t o b e abou t

IO 2 Sv 1 , an dth e additiona l damag e t o late r generation s t o b e o f th e sam e magnitude
. Th e risk facto r fo r radiatio n protectio n purpose s i s give n i n paragrap h 60
. Red bone marrow (44 ) Th e re dbon e marro w i s take n t o b e th e tissu e mainl y involve di n th e causatio n o f radiation-induce dleukaemia ; othe r blood

formin g tissue s ar e though t t o pla y amino r rol e i n leukaemogenesis
. Observation s o n human s irradiate dfo r

therapeuti c purpose s o r o n Japanes e survivor s o f nuclea r explosion s indicat e tha t

th e incidenc e o f

radiation

induce dleukaemi areache s it s pea k withi n a few year s afte r

irradiation , an dreturn s t o pre irradiatio n level s afte r

abou t 2 5 years . Fo r radiatio n protectio n purpose s th e ris k facto r fo r leukaemi ai s take n t o b e 210* 3 Sv- 1

. (45 ) Th e haematopoieti c cell s i n adult s ar e assume dt o b e randoml y distribute d throughou t

th e haematopoieti c marro w withi n trabecula r

bon e (se e ICRPPublication 11). Therefore , dos e equivalen t t o thos e cell s i s calculate da s th e averag e ove r th e tissu e whic h entirel y fill s th e cavitie s withi n trabecula r

bone
. (46 ) Anima l experiment s hav e indicate d tha t aprotracte dabsorbe ddos e o f 2 0 G y (gamm aradiation ) ove r alifetim e woul dne t impai r th e haematopoieti c functio n o f th e re d bon e marrow . I n ma n th e impairmen t c f functio n o f

th e re dbon e marro w i s no t considere dlikel y t o b e alimitin g effect , provi

de dtha t occupationa l non-stochasti c dos e limit s ar e se t

a t th e level s recommende di n paragrap h 103
. Bone (47 ) Th e radiosensitiv e cell s i n bon e hav e bee n identifie da s th e endostea l cell s an d epithelia l cell s o n bon e surface s (se e ICR 0 Publication 11). Th e Commissio n recom mend s that , wher e possible , dos e equivalen t i n bon e shoul dappl y t o th e endostea l cell s an d cell s o n bon e surfaces , an dshoul db e calcu

late da s a n averag e ove r

tissu e u p t o adistanc e o f 10^ mfro mth e relevan t bon e surfaces
. (48 ) A revie w b y th e Commissio n o f th e radiosensitivit y o f

bon e i n relatio n t o th e developmen t

o f radiation-induce dcancer indicate s that , pe r

uni t dos e equivalent , i

v i s muc h les s sensitiv e tha r marrow , lun g ant ! Ihyro i radiatio n pnotecco n th e r cance r i s take n t o be' 5 3 0 - 1 Lung (49 ) Cance r

o f th e lun g I miner s expose dt o hig h rado n an dit s deca y prod i difficul t t o deriv e aqua n ris k i n term s o f

dose , b e rang e i n th e est i mate s tha t dos e pe r uni t concentrati c However , ike epidem i make s i t possibl e t o se t

Ii i concentratio n o f

rado n d c ai r an dth e lengt h o f

tim e J a s t o ensur e a n adequat e d t A mor e detaile ddiscussio n b e foun di n th e forthcom i mitte e 2' s tas k

grou p o n i thei r daughte r

products
. (50 ) Cance r

o f th e lun g t t o radiatio n exposur e ha s n peopl e wh o hav e worke c material s i n particulat e fo r ium , eve n thoug h som e o f i abov e curren t

limits
. A s paragrap h 33 , th e Commi : th e hazar do f

particulat e n i s likel y t o b e les s tha n materia l distribute dunif < th e lung
. (51 ) Ther e i s evidenc e th i tio n ca n als o induc e lun g c : presen t indicatio n i s tha t cance r i s abou t th e sam e a s opmento f

leukaemia ; thi s < t o b e modifie dwhe n fu n availabl e o n th e time-cour s o f lun g cance r

afte r irradia t protectio n purpose s th e ri s cance r i s take n t o b e 210~ 3 S

^ Pulmonary lymphoid

tisi ula r cas e o f importanc e con t o f inhale dparticle s contain iCR P larrow e dbon e marro w i s take n t o b e th e l y involve di n th e causatio n o f duce dleukaemia ; othe r blood

sue s ar e though t

t o pla y amino r kaemogenesis
. Observation s o n adiate dfo r

therapeuti c purpose s es e survivor s o f

nuclea r explosion s a t th e incidenc e o f

radiation

kaemi areache s it s pea k withi n a te r irradiation , an dreturn s t o pre level s afte r

abou t 2 5 years . Fo r rotectio n purpose s th e ris k facto r li ai s take n t o b e 2 IO" 3 Sv-'
. haematopoieti c cell s i n adult s ar e t o b e randoml y distribute d th e haematopoieti c marro w ;cula r bon e (se e ICRPPublication ore , dos e equivalen t

t o thos e cell s da s th e averag e ove r

th e tissu e irel y fill s th e cavitie s withi n 30ne . ma l experiment s hav e indicate d tracte d absorbe ddos e o f 2 0 G y diation ) ove r

alifetim e woul dno t laematopoieti c functio n o f th e re d ow . I n ma n th e impairmen t o f i f th e re dbon e marro w i s no t likel y t o b e alimitin g effect , provi

Kcupationa l non-stochasti c dos e ^e t a t th e level s recommende di n 103
.

radiosensitiv e cell s i n bon e hav e ifie da s th e endostea l cell s an d ell s o n bon e surface s (se e ICRP i 11). Th e Commissio n recom -

. , wher e possible , dos e equivalen t ul d appl y t o th e endostea l cell s an d n e surfaces , an dshoul db e calcu

iverag e ove r

tissu e u p t o adistanc e a mth e relevan t

bon e surfaces , evie w b y th e Commissio n o f th e ivity o f bon e i n relatio n t o th e n t o f radiation-induce dcance r iat , pe r uni t dos e equivalent , i

t i s RECOMMENDATION S O F TH E ICR P 1 1 muc h les s sensitiv e tha n breast , re dbon e marrow , lun g an dthyroid
. Fo r purpose s o f adiatio n protectio n th e ris k facto r fo r bon e cance r i s take n t o b e 5 10 - 4 Sv 1

. Lung (49 ) Cance r

o f th e lun g ha s bee n observe di n miner s expose dt o hig h concentration s o f :ado n an dit s deca y products
. I n miner s i t i s difficul t t o deriv e aquantitativ e estimat e o f :is k i n term s o f

dose , becaus e o f

th e grea t rang e i n th e estimate s tha t hav e bee n mad e o f ;.!os e pe r uni t concentratio n o f

activit y i n air
. However , th e epidemiologica l evidenc e make s i t possibl e t o se t

limit s combinin g th e concentratio n o f

rado n daughte r

product s i n i:i r an dth e lengt h o f

tim e spen t

i n tha t air , s o a s t o ensur e a n adequat e degre e o f protection
. A mor e detaile ddiscussio n o f thi s subjec t

i s t o b e foun di n th e forthcomin g repor t o f Com

mitte e 2' s tas k

grou p o n radon , thoro n an d r heir daughte r products
. (50 ) Cance r

o f th e lun g clearl y attributabl e t o radiatio n exposur e ha s no t bee n reporte di n peopl e wh o hav e worke dwit h radioactiv e material s i n particulat e form , suc h a s pluton

ium , eve n thoug h som e o f the mwer e expose d abov e curren t

limits
. .A s alread y note di n paragrap h 33 , th e Commissio n believe s tha t th e hazar do f

particulat e materia l i n th e lun g i s likel y t o b e les s tha n tha t o f th e sam e materia l distribute duniforml y throughou t th e lung
. (51 ) Ther e i s evidenc e tha t externa l irradia

tio n ca n als o induc e lun g cance r i n man . Th e presen t indicatio n i s tha t

th e ris k o f lun g cance r i s abou t th e sam e a s tha t

fo r th e devel

opmen t o f leukaemia ; thi s estimat e ma y nee d t o b e modifie dwhe n furthe r dat abecom e availabl e o n th e time-cours e o f developmen t o f lun g cance r

afte r irradiation
. Fo r

radiatio n protectio n purpose s th e ris k facto r fo r lun g cance r i s take n t o b e 2 10" 3 S v1

. Pulmonary lymphoid

tissue (52 ) A partic

ula r cas e o f importanc e concern s th e retentio n o f inhale dparticle s containin g insolubl e com pound s i n bronchopulmonar y lymp h nodes , whic h compris e abou t

1 % o f al l lymphoi d tissu e i n th e body
. Thei r selectiv e irradiatio n ca n b e regarde da s correspondin g t o extreme
ly non-unifor mirradiatio n o f th e lymphoi d tissu e a s awhol e an ds o probabl y involvin g a lowe r hazar dtha n i f

th e containe dactivit y wer e uniforml y distribute dthroug h th e tota l mas s o f lymphoi dtissue
. Fo r

irradiatio n o f lymphocytes , however , th e non-uniformit y i s les s extreme , owin g t o th e norma l circulatio n o f lymphocyte s throug h th e lymp h node s o f thebody
. (53 ) Autops y dat afro mme n wh o ha d previousl y inhale dplutoniu mparticulate s indicat e tha t

th e mea n concentratio n o f plutoniu ma s average dove r th e tota l mas s o f al l lymphoi dtissu e i s likel y t o b e substantiall y les s tha n th e mea n concentratio n i n lun g tissues
. Sinc e th e lun g i s regarde da s o f highe r sensitivit y tha n th e lymphoi dtissue , i t i s t o b e assume dtha t

th e irradiatio n o f

lun g i s likel y t o b e mor e limitin g tha n tha t o f lymphoi d tissu e i n determinin g th e dos e limitatio n fo r suc h inhale dinsolubl e radioactiv e particu

lates
. (54 ) Fo r th e purpose s o f

radiatio n protec
tio n therefor e th e Commissio n consider s that , i n adults , i t

wil l b e satisfactor y t o conside r th e trachea , bronchi , pulmonar y regio n an d pulmonar y lymp h node s a s on e composit e orga n o f mas s 1 kg , t o whic h dos e limitatio n fo r th e lun g shoul dapply
. Thyroid (55 ) Th e cell s a t

ris k i n th e thyroi dglan d appea r t o b e th e epithelia l cell s o f th e thyroi d follicle s fo r

whic h th e dos e calculatio n shoul d b e made
. I n mos t

case s th e mea n dos e t o th e whol e glan dwill b e substantiall y th e sam e a s th e dos e t o thes e cells
. (56 ) Th e sensitivit y o f

th e thyroi dt o th e induction o f

cance r b y radiatio n appear s t o b e highe r tha n tha t o f th e re dbon e marro w t o th e developmen t

o f leukaemia
. However , th e mortality fro mthes e thyroi dcancer s i s muc h lowe r tha n fo r leukaemia , primaril y becaus e1 2 RECOMMENDATION S O F TH E ICRP

o f th e succes s i n th e treatmen t o f thyroi d cance r an dth e slo w progres s o f thi s typ e o f tumour
. Th e overal l mortalit y ris k facto r i s considere dt o b e abou t

on e quarte r

o f tha t fo r th e re dbon e marrow ; fo r radiatio n protectio n purpose s th e ris k

facto r i s take n a s 5 l.O - 4 Sv 1

. Breast (57 ) Dat ao n th e developmen t o f breas t cancer , followin g irradiatio n o f women , sugges t that , durin g reproductiv e life , th e femal e breas t

ma y b e on e o f

th e mor e radio

sensitiv e tissue s o f

th e huma n body
. Ther e ar e indication s that , unde r

thes e circumstances , th e ris k facto r fo r breas t cance r ma y b e afe w time s highe r

tha n tha t

fo r leukaemia
. Fo r radiatio n protectio n purpose s th e ris k facto r i s take n t o b e 2. 5 10- 3 ,S\•- ' (se e als o paragrap h 38)
. Risk of cancer in all other tissues (58 ) I n additio n t o thos e tissue s discusse d above , forwhic h a n approximat e estimat e ha s bee n mad e o f

th e frequenc y with whic h malignancie s ar e induce db y moderat e dose s o f radiation , ther e ar e othe r tissue s (e.g
. stomach , lowe r

larg e intestine , salivar y gland s an dprobabl y liver ) fo r whic h ther e i s evidenc e tha t

radiatio n i s als o carcinogeni c a t moderat e doses
. However , fo r thes e tissue s n o estimat e ca n ye t

b e mad e o f

th e ris k factor , althoug h i t

i s likel y tha t

thi s i s low
. Ther e ar e othe r tissues , suc h a s muscl e an dadipos e tissue , fo r

whic h littl e evidenc e ha s bee n obtaine do f

an y tumou r

inductio n a t moderat e doses
. (59 ) Som e estimat e ca n b e obtained,.how

ever , o f th e tota l o f

al l malignancie s induced , relativ e t o th e ris k

o f leukaemi ainduce d unde r th e sam e condition s o f .irradiation
. Fro mthi s evidenc e i t

appear s likel y tha t

th e majorit y o f

al l induce dmalignancie s aris e i n thos e tissue s fro mwhic h approximat e esti

mate s o f ris k hav e bee n obtained
. O n thi s basi s i t i s estimate dtha t

th e combine dris k

o f malignanc y i n al l remainin g unspecifie d tissue s i s unlikel y t o excee d5 10 - 3 S v 1 , an di t i s furthe r assume dtha t

n o singl e tissu e i s responsibl e fo r

mor e tha n one-fift h o f thi s value
. Total stochastic risk

from uniform whole body irradiation (60 ) Fo r th e purpose s o f

radiatio n protec
tio n involvin g individuals, th e Commissio n conclude s tha t

th e mortalit y ris k

facto r fo r radiation-induce dcancer s i s abou t 10 - 2 Sv 1 , a s a n averag e fo r

bot h sexe s an dal l ages . Th e averag e ris k

facto r fo r hereditar y effects , a s expresse di n th e firs t

tw o generations , woul d b e substantiall y lowe r

tha n this , whe n accoun t i s take n o f

th e proportio n o f

exposure s tha t

i s likel y t o b e geneticall y significant , an dca n b e take n a s abou t

4 10- ' Sv 1

. Bot h fo r th e somatic , an dfo r

th e hereditar y ris k

factor , th e estimate s wil l diffe r

somewha t

fo r worker s an dfo r member s o f

th e genera l public , be

caus e o f th e differenc e i n ag e structur e o f th e tw o populations
. Thes e difference s i n tota l risk, however , ar e no t

sufficientl y larg e t o warran t th e us e o f

separat e value s fo r

protec
tio n purpose s i n th e tw o cases . However , th e assessmen t

o f th e total population detriment du e t o radiatio n fro magive n exposur e shoul d als o tak e accoun t

o f th e tota l risk

o f hereditar y damag e tha t

ma y b e expresse di n al l subsequen t

generations
. Thi s risk , pe r uni t :dose , i s considere dt o b e abou t twic e tha t whic h i s expresse di n th e firs t tw o generation s only
.
Lens (61 ) Whe n th e len s i s subjecte dt o protracte d irradiatio n ove r

th e occupationa l lifetim e wit h hig h o r

low-LE T radiatio n i t ca n b e conclude dtha t

atota l dos e equivalen t

o f 1 5 S v woul db e belo w th e threshol dfo r th e produc

tio n o f an y len s opacificatio n tha t woul d "interfere with vision
. Th e Commissio n there

for e recommend s tha t

fo r radiatio n worker s th e annua l dose-equivalen t limi t fo r th e len s shoul db e derive dfro mth e abov e dos e P.1 9

equivalen t

delivere d over : (se e paragrap h (62 ) I n admit anterio r epiiSa e KM)
. s.the«qua t lu mofth e ca i regio n generally'consi i oftheleusmos i susceptibl e len s opacities
. Fo r

t'he p u protectio n tfe e equato r r . considere dtt© lji

e 3 m mb e th e eye . Skin (63 ) InoomunarisoB i with discussed , sl l i i s thoug h liabl e todewaiopfata l can e However , COS T rreticaHly-u n i n th e ski n unj. y occu r

af t absorbe ddose s o f

3 0 G y ove r week s o r

month s t o : skin
. Therefore , th e us e . limi t fo r expo s ar e ove r

th e lifetime , shoul dpreven t suc h non-stoctiasti c chan t grap h 103)
. (64 ) Th e thicknes s o t considerabl y fro mon e p t another
. Th e basa l cel l lay > i s take n t o bt

th e ski n ti : Becaus e o f

undulation s i n an dbecause © vth e finit e t h arang e o f

5 © -10 0 [tin (o r appropriat e fo r

specifyin i sensitiv e laye r

o f mos t part : practic e ar e wo t

protecte dI therefor e expose ddirectl y practica l dos< : assessmen t recommend s th e us e o f

ad < reasonablent e a n value
..R P ikel y t o exceed5 IO- 3 Sv 1 , an di t i s jme d tha t

n o singl e tissu e i s fo r more tha n one-fift

h o f thi s

•stic risk from uniform whole Hon h e purpose s of

radiatio n protec
lg individuals, th e Commissio n va t th e mortality ris k

facto r fo r ducedcancer s i s abou t

IO - 2 Sv 1 , 5 fo r both sexe s an dal l ages . Th e facto r for hereditar y effects , a s th e first tw o generations , woul d ill y lowe r tha n this , whe

n accoun t i e proportio n o

f exposure s tha t

i s enetically significant , an dcan b e >ou t 4 10- 3 Sv'
. Bot

h for th e d for th e hereditary ris k

factor , ; wil l diffe r somewha t fo r worker s nber s of th e genera

l public , be

differenc e in ag e structur e o f th e ions
. Thes e difference s in tota l ;r , ar e no t

sufficiently larg e t o is e o f separat e value s for

protec
s i n th e tw o cases . However , th e i f th e total population detriment ion fro magive n exposure shoul d iccoun t of th e tota l ris k

o f amag e tha t

ma y b e expresse di

n i t generations
. Thi s risk , per uni t sidere dt o b e abou t

twic e tha t essedin th e firs t

tw o generation s

th e lens i s subjectedt o protracte d >ve r th e occupationa l lifetime r low-LET radiatio n i t

ca n b e a t atota l dos e equivalent

of 1 5 S v o w th e threshol dfo

r th e produc

len s opacificatio n tha t

woul d 1 vision
. Th e Commissio n there

end s tha t fo r radiatio n worker s ose-equivalent

limit fo r th e len s lerive dfro

mth e abov e dos e RECOMMENDATION S O F TH E ICR P equivalent delivere dove

r th e workin g lifetime (se e paragrap h 103)
. (62) I n adult s th e equatoria l portio n o f th e anterio r epitheliu mof

th e len s i s th e anatomi

ca l regio n generall y considere dt o b e th e part o f th e len s mos t

susceptibl e t o th e inductio n o f len s opacities
. Fo r

th e purpose s o

f radiatio n protectio n th e equato r

o f th e len s ca

n b e considere dt o li e 3 m

mbehin dth e surfac e o

f th e eye . Skin (63 ) I n compariso n wit

h th e tissue s already discussed , ski n i s though t t o b e muc h les s liabl e t o develo p fatal cancer after irradiation.
. ' i owever , cosmetically-unacceptabl e change s i n th e ski n ma

y occur after irradiatio n wit

h ;:osorbe d dose s of

2 0 G y o r more , delivere d ove r weeks o r month s t o limite dportion s of >kin
. Therefore , th e us e of thi s value , a s a limi t fo r exposure ove

r th e whol e occupationa l lifetime , shoul dprevent

th e occurrenc e o

f >uc h non-stochasti c change s (see als o para graph 103)
. (64 ) Th e thicknes s o f

th e ski n varie s considerabl y fromon e part of th e body t o another
. Th e basal cel

l laye r of th e epidermi s i s take n t o b e th e ski n tissu e mos t a t risk
. Becaus e of undulation s in th e basal cell laye r an dbecaus e of

th e finit e thicknes s o

f it s cells , arang e of

50-10 0 pirn (o r

5-1 0 m g cm- 2) i s appropriat e fo

r specifyin g th e dept

h of th e sensitiv e laye

r of mos t part s o f th e ski n tha t

i n practic e ar e no t

protecte db

y clothin g an dar e therefore expose ddirectl y t o radiation
. Fo r practica l dos e assessment

th e Commissio n recommend s th e us e of

adept h of 7 0 pm a s a reasonabl e mea

n value
. 2 3 Children and

foetuses (65 ) Exposur e before birth o r durin g chil d hoo dma y interfer e wit

h subsequen t

growt h an ddevelopment , dependin g o n factor s suc h a s dos e an dag e at

irradiation
. Susceptibility t o th e inductio n o

f certai n malignancie s als o appear s t o b e higher

durin g th e prenata l an d childhoo dperiod s tha n durin g adul t life
. Tissues of low sensitivity (66 ) It i s now establishe dtha t

ther i ar e variou s tissue s in whic h th e developmen t of malignanc y followin g irradiatio n seem s t o b e ver y rare , a s evidence dby th e fac t tha t epidemiologica

l survey s hav e s o fa

r no t show n exces s rate s o

f malignanc y i n suc h tissues
. Fo r

thes e tissue s dos e limitatio n i s base do n th e possibilit

y o f vascula r o r othe r deleteriou s changes
. Ther e ma y als o b e som

e tissues , for

exampl e thos e containin g non nucleate dcells , th e irradiatio n of whic h ca n b e ignore dfor

th e purpose s o f

radiatio w protection
. Other effects (67 ) Othe r tha n th e specifi c effect s alread y discussed , ther e i s n o goo devidenc e o f impairmen t

o f functio n of

organ s an dtissue s at th e level s of

dos e normall y encountere di n radiatio n work
. Th e evidenc e for life-shorten

ing fromeffect s othe r

tha n tumou r

inductio n i s inconclusiv e an dcanno t b e use d quantita

tively
. Moreover , i

t seem s unlikel y tha t

an y majo r hazar dfromirradiatio n a t recom mende dlevel s ha s been overlooked , a s Lidge d b y th e evidenc e fromheavily irradiate d populations , observe dfor period s u p t o 3 0 years .P.2 1

: il ! ' : 1 4 RECOMMENDATION S O F TH E ICR P



### E . TH E SYSTE M O F DOS E LIMITATIO N (68 ) I n orde r

t o achiev e th e objective s liste d i n paragrap h 12 , th e Commissio n recom mend s asyste mo f

dos e limitation , th e mai n purpose s o f

whic h ar e t o ensur e tha t n o sourc e o f exposur e i s unjustifie di n relatio n t o it s benefit s o r

thos e o f an y availabl e alternative , tha t an y necessar y exposure s ar e kep t a s lo w a s i s reasonabl y achievable , an dtha t th e dos e equivalent s receive dd o no t excee dcertai n specifie dlimit s an dtha t

allowanc e i s mad e fo r futur e development
. Thes e point s ar e expande dfurthe r

i n th e followin g paragraphs
. (69 ) Ideall y th e acceptabilit y o f apropose d operatio n o r

practic e involvin g exposur e t o radiatio n shoul db e determine db y cost
benefi t analysis , th e purpos e o f whic h i s t o ensur e tha t

th e tota l detrimen t

shoul db e appropriatel y smal l i n relatio n t o th e benefi t resultin g fro mth e introductio n o f th e propose dactivity
. Comparison s betwee n practice s shoul db e mad e afte r th e applicatio n o f th e procedur e o f

optimizatio n (se e paragraph s 72-76)
. Th e choic e betwee n practice s wil l depen do n man y factors , onl y som e o f whic h wil l b e associate dwit h radia

tio n protection
. Fo r

"thi s reason , th e compari

so n o f practice s i s no t

discusse dfurthe r

i n thi s report
. Optimization , o n th e othe r hand , shoul db e amajo r

par t o f practica l radiatio n protection ; i t

i s discusse di n mor e detai l i n th e followin g paragraphs
. (70 ) I n cost-benefi t

analysi s th e benefit s ar e take n t o includ e al l th e benefit s accruin g t o society , an dno t

jus t thos e tha t

wil l b e receive d b y particula r

group s o r

individuals
. I n certai n circumstance s benefit s ca n b e quantified , but , whe n the y contribut e t o th e satisfactio n o f huma n desires , suc h quantificatio n ma y prov e difficult
. Cost s ar e considere da s comprisin g th e su mtota l o f al l negativ e aspect s o f

a n operation , includin g monetar y cost s an dan y damag e t o huma n healt h o r t o th e environment
. Sinc e th e distributio n throug h th e populatio n o f thes e benefit s an d cost s wil l no t b e th e same , thi s broa dproces s o f balancin g would , however , b e legitimat e onl y i f th e detrimen t

t o eac h individua l doe s no t excee da n acceptabl e level
. I n exercisin g thi s proces s i n relatio n t o ionizin g radiation , th e individua l limitatio n o f detrimen t

woul d b e achieve db y complianc e wit h th e Commis

sion' s dose-equivalen t

limits
. (71 ) I t ma y thu s b e necessar y t o mak e subjectiv e valu e judgment s i n orde r t o com par e th e relativ e importanc e o f th e cost s impose do n huma n healt h b y radiatio n exposur e wit h othe r

economi c an dsocia l factors
. I n thi s respec t

radiatio n i s no t

unique , an dth e sam e statemen t coul db e mad e i n respec t o f anumbe r

o f othe r agent s t o whic h mankin di s exposed
. The bases

for deciding what

is reasonably achievable in dose reduction (72 ) Man y o f

th e factor s describe di n th e precedin g paragraph s wil l no t b e necessar y fo r decidin g wha t

i s reasonabl y achievabl e i n dos e reductio n belo w th e recommende d limits
. Fo r

thi s purpos e th e questio n i s whethe r o r no t th e activit y i s bein g performe d a t asufficientl y lo w leve l o f collectiv e dos e equivalen t

(an dusually , therefore , o f detri

ment ) s o tha t

an y furthe r

reductio n i n dos e woul dno t

justif y th e incrementa l cos t re quire dt o accomplis h it
. I n makin g thi s deter

mination , th e cost-benefi t analysi s shift s fro maconsideratio n o f th e total

benefi t o f th e activit y t o th e change i n ne t benefi t tha t migh t b e involve di n requirin g th e activit y t o b e performe da t

on e leve l o f

dos e rathe r

tha n another
. (73 ) Th e ne t

benefit , B, o f

aproduc t

o r a n operatio n involvin g irradiatio n ca n b e regarde da s equa l t o th e differenc e betwee n it s gros s benefit , V, an dth e su mo f thre e com ponents : th e basi c productio n cost , P, th e cos t .o f achievin g aselecte dleve l o f protection , X, an dth e cost , YL o f th e d c th e operatio n o r

i n th e p disposa l o f

th e product , s c B= V—{P+ Cos t a s use dr

er e inclu d purel y econo mccosts
. (74 ) I n orde r

t o determ i tio n i n exposur e i s "reaso i i s necessar y t o conside r o increas e o f

benefi t fro ms t o n th e othe r

th e increas e o ; achievement
. I n th e diffe i analysis , intende dt o maxi i th e independen t

variabl e h equivalent , S , mu mne t benefi t woul db e dV_ dS Sinc e Kand/ > fro mth e r

dJP ~dS dX 

### d ?
ca n b e consi * S fo r agive n practice , i optimizatio n conditio n i s S*suc h that t tio n pe r uni t reductio n o equivalent , i. e

'.. i e increas e i r dos e equi v detrimen t 

# ( l 

# i
However , othe r

compo n detriment , suc h a s restrict ! o r us e o f areas , will no t

no r th e collectiv e dos e equiv a som e cases , b e influence d1 equivalen t

i n th e expose dg i (75 ) Assessment s bas e equatio n ma y b e helpe db > amonetar y valu e t o th e un i equivalent
. Althoug h i n \ difficul t t o quantif

y eve n ponent s o f

tli e detriment , s th e cos t equivalen t

o f am a published , and , wit h al l th e provid e possibl e quantita ; decision-m aring proces s ( s tion 22).:R P 

### MITATIO N tb e th e same , thi s broa dproces s ; would , however , b e legitimate etrimen t t o eac h individual doe s n acceptabl e level
. In exercisin g i n relatio n t o ionizin g radiation , a l limitatio n of

detrimen t

woul d b y complianc e wit

h th e Commis

- ;quivalen t limits
. a y thu s b e necessar

y t o make ilu e judgment s in orde r

t o com lativ e importanc e o f

th e cost s i human healt

h b y radiatio n it h othe r economi c an d socia

l li s respec t radiatio n i s no t

unique , n e statemen t

coul db e mad e i n numbe r o f othe r agent s t o whic h exposed
.
>r deciding what

is reasonably t dose reduction i o f th e factor s describe din th e iragraph s wil

l no t b e necessar

y wha t i s reasonabl y achievabl e in [io n belo w th e recommende d thi s purpos e th e questio n i s o t th e activit y i s bein g performe d ntly lo w leve l o f collectiv e dos e in d usually , therefore , o

f detri

t t any furthe r

reductio n in dos e justif y th e incremental cos t

re - :omplis h it
. I n makin g thi s deter

h e cost-benefi t

analysi s shift s ideratio n o f

th e total benefit o f t o th e change i

n ne t benefi t tha t olved i n requirin g th e activit

y t o da t on e leve l o f dos e rathe r

tha n ie t benefit , B, o

f aproduc t

o r an involving irradiatio n ca n b e .qual't o th e differenc e between it s t , V, an d th e su

mo f thre e com basi c productio n cost , P, th e cos t aselecte d leve

l o f protection , X, RECOMMENDATION S O F TH E ICR P

an dth e cost , Y, o f

th e detrimen t

involve di n th.e operatio n o r

i n th e production , us e an d disposa l o f th e product , s o tha t B= V—(P-rX+ Y) Cos t a s use dher e include s socia l a s well a s ourel y economi c costs
. (74 ) I n orde r

t o determin e whether

areduc

tio n i n exposure i s "reasonably achievable " i t is necessar y t o consider

o n th e on e han dth e increas e o f

benefi t fro msuc h areductio n an d o n th e othe r

th e increas e of

cos t involve di n it s achievement
. I n th e differential cost-benefi t analysis , intende dt o maximiz e th e ne t benefit , th.e independen t

variabl e i s th e collectiv e dos e equivalent , S , fromth e practice
. Th e opti

mu mnet benefi t woul db e attaine di

f dy_fdPdX

dY\_ dS \dS

+ dS + dSJ~ Since KandPca n b e considere dconstan t wit h V fo r agive n practice , i t

follow s tha t

th e optimizatio n conditio n i s fulfilleda t avalu e S*suc h tha t

th e increas e in th e cos t

o f protec
tion pe r uni t dos e equivalent

balance s th e reductio n o f

detrimen t

per uni t dos e equivalent , i.e
.

d_T \ dSj s . \dSj S a However , othe r

component s o f

radiatio n detriment , such a s restriction s i n th e acces s t o o r us e o f areas , wil l no t normall y b e relate dt o th e collectiv e dos e equivalen t an dmay , in som e cases , b e influence db

y th e highes t

dos e equivalen t i n th e expose dgroup . (75 ) Assessment s base do n th e abov e equatio n ma

y b e helpe db y th e assignmen t o f amonetar y valu e t o th e uni t

o f collectiv e dos e equivalent
. Althoug h in practic e i t i s ver y difficult t o quantif

y eve n som e o f th e com ponent s of th e detriment , severa

l estimate s of th e cos t equivalent

of ama n siever t hav e been published , and , wit

h all thei r limitations , they provide possibl e quantitativ e input s t o th e decision-makin g proces s (see ICRPPublication 22). 1 5 (76 ) Th e applicatio n o f th e processe s describe din precedin g paragraph s doe s no t alway s provid e sufficient

protectio n fo r

th e individual , particularl y when benefit s an d cost s ar e no t

identicall y distribute dthroug h th e population
. Fo r

agiven practice , regard

les s o f th e resul t

o f th e differential cost
benefi t analysis , individual dose-equiv£.len t limit s mus t

b e respected
. I

f th e us e o

f th e optima l collectiv e dos e equivalen t woul d caus e any individual t o excee da n appro p riat e limit , i t woul db e necessar

y t o se t th e collectiv e dos e equivalen t

a t th e poin t where individua l dose-equivalen t

limit s woul db e respected
. Dose-equivalent

limits

—general (77 ) Th e dos e equivalen t limit s forrherl y recommende db y th e Commissio n hav e bee n i n effect for ove r 2 0 years . The y hav e bee n widely use dinternationall y an dhav e bee n incorporate dint o legislatio n in anum t er of countrie s an dregions
. Furthermore , ther e i s n o evidenc e t o indicat e tha t th e Commis i ion ' s recommende dsystemo f

dos e limitatio n ha s faile dt o provid e an adequat e leve l of safety
. However , th e Commissio n believe s th at i t i s appropriat e t o review it s dose-equivalen t limit s in th e light

o f presen t knowledjje , t o determin e whether

any chang e in th e level s i s calle dfor
. Th e Commission' s recommende d dose-equivalen t

limit s ar e discusse d i n para graph s 103-108
. (78 ) Almos t

ever y exposur e o f

th e bod y involve s th e irradiatio n o f mor e tha n on e tissue , an dtherefore , for

reason s referre dt o i n paragrap h 36 , th e Commissio n believe s that , for stochasti c effects , i t

i s appropriat e t o recommen dadose-equivalen t limi t base do n th e tota l ris k

o f al l tissue s irradiated
. Thi s systemincorporate s th e settin g o f asingl e dose-equivalen t

limi t for uniformirradiatio n of th e whol e body (see paragraph s 10 4 an d 119) an dasystemdesigne dt o ensur e tna t th e tota l ris k fro mirradiatio n of

part s of th e bod y doe s no t exceedtha t

fro muniformirradiatio n of th e whol e body (see paragraph s 104 , 10 5 an d125)
. Th e systemi s further subjec t t o th eP.2 3

1 6 RECOMMENDATION S O F TH E ICR P constrain t tha t n o singl e tissu e shoul dreceiv e more tha n aspecifie ddose-equivalent limit t o prevent th e occurrenc e of

non-stochasti c damag e (see paragraph s 10 3 an d126)
. Ideally , th e recommendation s of th e Commissio n shoul db e designe dt o ensure tha t th e detrimen t fromany year' s practic e shoul db e limite d t o avalu e independen t of th e distribu

tio n o f dos e equivalen t

withi n th e body
. (79 ) Th e Commission' s dos e limitation s ar e intende dt o relat e t o th e dose-equivalent com mitmen t resultin g from1 yea

r of aparticular practice
. Wit

h mos t external irradiation , an d wit h short-live dradionuclide s take n int o th e body , th e committe ddos e equivalent froma yea r o f practic e wil

l b e receive deither

instan

taneousl y o r

withi n ashort

time , an dthu s shoul db e subjec t

t o th e limi t

for tha t year . However , th e committe ddos e equivalen t from1 year' s intak e of

along-live dradio

nuclid e refer s t o dos e equivalent s delivere d ove r alon g period , eve

n u p t o man y years , after th e yea r in question
. I n principle , th e us e o f th e dose-equivalent

commitment

concep t doe s permi t

th e dos e equivalent

receivedi n a singl e yea r t o exceedth e annua l limit (e.g
. i n th e cas e of a n intak e i n 1 yea

r o f amateria l o f lon g effectiv e hal f

life , followe db

y an intak e in th e next yea r equal t o an ALI * o

f amateria l of short effectiv e hal f

life)
. I n practic e suc h situation s wil

l b e rar e an dth e dos e equivalent durin g any yea

r in exces s o

f th e annua l limit wil l normall y b e small
. (80 ) Th e Commissio n consider s that , in assessin g risk s for

th e purpose s o

f settin g th e dose-equivalen t

limi t for individuals , th e hereditar y detrimen t

in th e immediate offsprin g o

f a n individual (i.e
. in th e firs t tw o generation s after

irradiation ) shoul db e adde d t o th e tota l of

any radiation-induce dsomati c detriment
. Th e presen t

indication s ar e tha t

a substantia l par t

of th e tota l hereditar

y harm appear s i n thes e firs t

tw o generation s of

a n individual' s offspring
. Th e har mt o b e receive db y al l subsequen t

generation s woul d

•Annua l Limi to f

Intake . nee dt o b e considere din any assessment o f tota l hereditary effects
. Th e reproductiv e lif e o f worker s expose dt o radiatio n i s considere d t o las t abou t on e thir do

f thei r workin g career , an dth e Commissio n ha s therefor e take n thi s facto r int o accoun t

in derivin g th e weightin g factor s give

n i n paragrap h 105
. (81 ) Th e Commission' s recommendation s deal quit e differentl y wit

h tw o distinc t

condi

tion s o f exposure : (i ) in which th e occurrenc e o f th e exposure i s foreseen an dcan b e limite dby contro l o f th e sourc e an dby th e appli

catio n of th e Commission' s systemo f dos e limitation , includin g th e develop

ment o f satisfactory operatin g pro cedures ; (ii ) i n whic h th e sourc e of

exposure i s no t subjec t t o control , s o tha t

an y subse

quen t exposure can b e limite din amount , if

a t all , only b

y remedial actions
. When asourc e o f

exposure i s subjec t

t o contro l i t i s feasibl e t o appl y th e Commis

sion' s syste

mo f dos e limitatio n (se

e paragrap h 12)
. Onc e suc h asystemha s bee n established , th e objectiv e shoul db e t o plan th e us e o f radiatio n source s i n suc h awa y that , i n norma l practice , th e systemwil l no t b e infringed
. Th e dose-equivalen t limit s assume th e additiona l critical functio n o f actin g a s a chec k o n prope r

an dadequat e workin g practice s a t

th e sourc e of

exposure . Th e dose

equivalent limit s shoul dno t

b e regarde da s a dividin g lin e betwee n safet

y an ddanger ; when limit s hav e been exceede db y asmal l amoun t i t i s generally mor e significant tha t ther e ha s bee n afailure o

f contro l tha n tha t

on e or more individual s hav e slightl y exceede dacertai n agree ddose
. (82) I n many practica l situation s i t wil l b e convenient

t o make us e o

f aderive dlimit , calculate dwit

h th e ai dof

amodel , which pro vide s aquantitativ e lin

k betwee n aparticular measurement an dth e r

e equivalent limi t o r int a paragrap h 14

0 et seq.). In i th e intentio n shoul db e t

c such tha t adherenc e t o i

t * certaint y of complianc e sion' s recommende ddos e However , failure t o adh

< limit wil l no t necessaril y achiev e complianc e wit

h recommendation s an dm more carefu l study o

f th e c matte r i s discusse di

n gre a F
. (83 ) Th e Commission' s are intende dt o limi t

s individuals , hereditary ef

f ate offsprin g o

f irradiat e hereditar y an dsomati c e

f I tio n a s awhole
. It

i s the t consider th e exposure o

f b i populations
. Th e Commis : e ddos e limit s appl y t o t

w posure , namei y occupati c genera l exposur e (see par a orga n o r tissu e th e limit equivalen t shal l refe r t o the dos e equivalent s contri b source s an dcommitte ddo s radioactivity take n hi: o t

h yea r of practice
. In relatio n limits , th e dos e equivalen t includ e contribution s fror
. cedure o r from"normal' ' (se e als o paragraph s 87-9 3 (84 ) Th e dose-equivale i bee n establishe dfor

occ u are regarde da s uppe r

Iir
. equivalent s ma

y hav e t monitore dan dcontrolle d limit s ar e no t

exceeded
. 1 equivalen t for member s of theoretical concept , inte n th e desig n an doperatio n o make s i t unlikel y tha t

indi v wil l receiv e mor e tha n t equivalent
. Th e effectiv checke db y assessment sICR P considere di n an y assessmen t o f itar y effects
. Th e reproductiv e lif e expose dt o radiatio n i s considere d : t on e thir do f

thei r workin g career , mmissio n ha s therefor e take n thi s accoun t i n derivin g th e weightin g : n i n paragrap h 105
. • Commission' s recommendation s iifferentl y wit h tw o distinc t condi

losure : hic h th e occurrenc e o f

th e exposur e oresee n an dca n b e limite db y ro l o f th e sourc e an db y th e appli

3 n o f th e Commission' s syste mo f

. - limitation , includin g th e develop

t o f satisfactor y operatin g pro ves ; hic h th e sourc e o f

exposur e i s no t ee t t o control , s o tha t

an y subse

i t exposur e ca n b e limite di n •unt , i f a t all , onl y b y remedia l 3ns
. ourc e o f exposur e i s subjec t

t o i s feasibl e t o appl y th e Commis

mo f dos e limitatio n (se e paragrap h uc h asyste mha s bee n established , iv e shoul db e t o pla n th e us e o f source s i n suc h awa y that , i n actice , th e syste mwil l no t b e Th e dose-equivalen t

limit s assum e na l critica l functio n o f

actin g a s a prope r an dadequat e workin g '
. th e sourc e o f

exposure . Th e dose

limit s shoul dno t

b e regarde da s a e betwee n safet y an ddanger ; whe n bee n exceede db y asmal l amoun t i t y mor e significan t

tha t ther e ha s ir e o f contro l tha n tha t

on e o r mor e
• hav e slightl y exceede dacertai n lan y practica l situation s i t wil l b e t o mak e us e o f

aderive dlimit , vit h th e ai do f

amodel , whic h pro ntitativ e lin k

betwee n aparticula r RECOMMENDATION S O F TH E ICR P 1 7 measuremen t

an dth e recommende ddose

cjuivalen t

limi t o r intak e limi t

(se e als o paragrap h 140et

seq.). I n derivin g suc h alimi t : he intentio n shoul db e t o establis h afigur e >:.tc h tha t adherenc e t o i t

wil l provid e virtua l certaint y o f

complianc e wit h th e Commis

sion' s recommende ddose-equivalen t limits
. However , failur e t o adher e t o th e derive d limi t wil l no t necessaril y impl y afailur e t o achiev e complianc e wit h th e Commission' s recommendation s an dma y requir e onl y a mor e carefu l stud y o f

th e circumstances
. Thi s matte r i s discusse di n greate r

detai l i n sectio n F
. (83 ) Th e Commission' s recommendation s ;re intende dt o limi t

somati c effect s i n individuals , hereditar y effect s i n th e immedi

at e offsprin g o f

irradiate dindividuals , an d hereditar y an dsomati c effect s i n th e popula

tio n a s awhole
. I t

i s therefor e necessar y t o .mside r th e exposur e o f

bot h individual s an d populations
. Th e Commission' s recommend

ed dos e limit s appl y t o tw o categorie s o f ex posure , namel y occupationa l exposur e an d genera l exposur e (se e paragrap h 137)
. I n an y orga n o r tissu e th e limitatio n o f th e dos e equivalen t shal l refe r

t o th e su mo f

th e annua l dos e equivalent s contribute db y externa l >ource s an dcommitte ddos e equivalent s fro m radioactivit y take n int o th e bod y durin g an y yea r o f practice
. I n relatio n t o dose-equivalen t limits , th e dos e equivalen t shal l no t b e hel dt o includ e contribution s fro man y medica l pro cedur e o r fro m"normal " natura l radiatio n (se e als o paragraph s 87-93)
. (84 ) Th e dose-equivalen t limit s tha t

hav e bee n establishe dfo r

occupationa l exposur e ar e regarde da s uppe r

limits , an dth e dos e equivalent s ma y hav e t o b e individuall y monitore dan dcontrolle dt o ensur e tha t th e limit s ar e no t

exceeded
. Limitatio n o f dos e equivalen t

fo r member s o f

th e publi c i s amor e theoretica l concept , intende dt o ensur e tha t th e desig n an doperatio n o f radiatio n source s make s i t unlikel y tha t

individual s i n th e publi c wil l receiv e mor e tha n th e specifie ddos e equivalent
. Th e effectivenes s o f thi s i s checke db y assessment s throug h samplin g procedure s an dstatistica l calculations , an d b y contro l o f

th e source s fro mwhic h th e exposur e i s expecte dt o arise , an donl y rarel y b y spo t check s o f

individua l exposures . (85 ) Th e basi s fo r

th e limitatio n o f

indi

vidua l exposures , eithe r o f worker s o r

o f member s o f

th e public , i s th e limi t fo r tn e weighte dmea n whol e bod y dos e equivalen t (se e paragrap h 104 ) an dno t th e derive dlimit s o r level s b y whic h th e dos e i s controlled
. Th e actua l dose s receive db y individual s wil l var y dependin g o n factor s suc h a s difference s i n thei r age , size , metabolis man dcustoms , a s wel l a s variation s i n thei r environment
. Wit h a n occupationally-expose dindividua l i t wil l ofte n b e sufficien t

t o us e derive dlimit s an d level s t o asses s hi s exposur e status
. Wit h exposur e o f

member s o f

th e publi c i t

i s usuall y feasibl e t o tak e accoun t o f thes e source s o f variabilit y b y th e selectio n o f appropriat e critica l group s withi n th e populatio n provide dth e critica l grou p i s smal l enoug h t o b e relativel y homogeneou s wit h respec t t o age , die t an dthos e aspect s o f

behaviou r

tha t affec t th e dose s received
. Suc h agrou p shoul d b e representativ e o f

thos e individual s i n th e populatio n expecte dt o receiv e th e highes t dos e equivalent , an dth e Commissio n believe s tha t i t wil l b e reasonabl e t o appl y th e appropriat e dose-equivalen t limi t fo r indivi

dua l member s o f

th e publi c t o th e weighte d mea n dos e equivalen t

o f thi s group . Becaus e o f th e innat e variabilit y withi n a n apparentl y homogeneou s grou p som e member s o f th e critica l grou p wil l i n fac t receiv e dos e equiva

lent s somewha t

highe r tha n th e mean . How

ever , becaus e o f

th e maximizin g assumption s used , th e dos e equivalen t actuall y receive d wil l usuall y b e lowe r

tha n th e estimate ddos e equivalen t

(se e als o sectio n G)
. (86 ) Befor e discussin g th e limitatio n o f dose s i n differen t

condition s o f

exposure , i t

i s first necessar y t o revie w th e relationshi p o f th e Commission' s recommende ddose

equivalen t

limit s t o exposure s fro mnatura l radiatio n an do f

patient s fro mmedica l procedures
.P.2 5

1 8 RECOMMENDATION S O F TH E ICR P Natural radiation and

dose-equivalent

limits (87 ) Man ha s alway s been expose dt o radia

tio n fromhi s natura l environment , th e basi c source s o f natura l radiatio n exposure bein g cosmi c rays , radioactivity i n rock s an dsoil , an dradioactiv e nuclide s incorporate dint o hi s tissues
. Th e dos e of

natura l radiatio n tha t

a perso n receive s depend s o n anumbe r o f factor s suc h a s th e height abov e sea-level a t which h e lives , th e amoun t an dtyp e of radioactiv e nuclide s in th e soi l in hi s neigh

bourhood , an dth e amoun t tha t he take s int o hi s bod y i n air , water

an dfood
. Th e tota l absorbe ddos e rat e i n mos t huma n tissue s fromnatura l radiatio n i s abou t one thousandth of

agra y pe r year , bu t absorbe d dos e rate s u p t o one-hundredth of agra y pe r year , o r more , hav e bee n reporte dfro m certai n limite darea s of

th e world
. (88 ) Man-mad e modification s of th e en vironmen t an dman' s activitie s ca

n increas e th e "normal " exposure t o natura l radiation
. Example s o f

thi s includ e mining , fligh

t a t hig h altitudes , an dth e us e of

buildin g material s containin g naturally-occurrin g radioactiv e nuclides
. Even livin g withi n ahous e i s ofte n sufficient t o increas e radiatio n exposure becaus e restricte d ventilatio n tend s t o leadt o an accumulatio n o f

radioactiv e gase s an d thei r deca y products
. (89 ) I n radiatio n protectio n th e Commis

sion' s recommende ddose-equivalent limit s hav e no t been regarde da s applyin g to , o r including , th e "normal " level s of natura l radiation , bu t

onl y a s bein g concerne dwit h thos e component s of

natura l radiatio n tha t resul t fro mman-mad e activitie s o r i n specia l environments
. Thi s convention , vali do n th e assumptio n of

linearit y (se e paragraph s 27

- 30) , i s justifie din th e sens e tha t th e Commis

sion' s recommende dlimit s ar e intende da s guide s for

plannin g purposes , an dthu s primaril y appl y t o man-mad e practices
. Clearly , however , ther e i s n o shar p dividin g lin e betwee n level s o

f natura l radiatio n tha t can b e regarde da s "normal " an dthos e tha t ar e mor e elevate dowin g t o huma n activitie s o r choic e o f environment
. Ther e wil

l there

for

e b e instance s in whic h judgmen t wil l hav e t o b e exercise da s t o whether th e componen t o f increase dnatura l radiatio n shoul do r shoul dno t

b e subjec t

t o th e Commission' s recommende dsystemof

dos e limitation
. (90) I t shoul db e emphasize dmoreover that , on th e premis e tha t th e frequenc y of radiatio n effect s i s linearl y proportiona l t o th e dos e received , suc h har ma s ma y b e cause d b y natura l radiatio n coul db e regarde da s independen t

of , an dsimply additiv e to , th e amoun t of har mtha t ma y b e cause dby any of th e man-mad e practice s involvin g radiatio n exposure t o whic h th e Commission' s limit s apply
. I n thi s sense , regional variation s in natura l radiatio n ar e regarde da s involvin g a correspondin g variatio n in detrimen t i n jus t th e same wa

y as , for example , regional varia

tion s in meteorological condition s o r volcani c activit y involv e difference s in th e ris k o f har m i n different

areas . O n thi s basi s ther e i s n o reaso n wh

y difference s in natura l radiatio n shoul daffec t

acceptabl e level s o

f man-mad e exposure , any more tha n difference s in othe r natura l risk s shoul ddo
. Medical exposures of

patients and dose-equivalent

limits (91 ) I n thes e recommendation s "medica l exposure " refer s t o th e intentiona l exposure o f patient s for

diagnosti c an dtherapeuti c purposes , an dt o th e exposure s resultin g from th e artificial replacemen t

of bod y organ s or function s (e.g
. by heart

pump s an dcardia c pace-makers)
. I t

applie s t o exposure s administere db y medica

l an dparamedical personnel
. I t

doe s no t refe r t o th e irradiatio n o f th e staf f involve din th e administratio n o f medica l exposure s t o patients , no r t o th e irradiatio n o f

on e patien t

b y another
. (92) Medica

l exposure is , in general , subjec t t o mos t o f th e Commission' s syste

mof dos e limitation , tha t

is : unnecessar

y exposure s shoul db e avoided ; necessar y exposure s shoul db e justifiabl e i n term s of benefit s that wouldno t otherwis e hav e been received ; an d th e dose s actuall y administere dshoul dbe limite dt o th e minimum wit h th e medica

l bene f patient
. Th e individual r

e i s himself th e direc t

reci resultin g fromth e proce

c i t i s no t appropriat e t o a

i value s of th e Commis s dose-equivalent

limit s to Wit h certai n medica

l ex r highe r leve l o f ris k ma y i i th e benefi t derive dtha n b th e Commissio n t o b e a

i pationa l exposure or

for e ofth e public
. (93 ) I t ha s alread y bee grap h 8 9 tha t

th e C o mende ddose-equivalen t fo r plannin g purpose s a

n ponen t "o f ris k resultin g practic e t o whic

h radiati o Under th e assumptio n c fro msuc h apractic e i s u

n fro mothe r sources , an di abl e t o consider

separate i fro msuc h practice s fror

r fro mmedica l exposure . sideration s detaile din Commissio n consider s t

l resultin g fro mmedica

l e > influenc e any of

th e p limitatio n applie dt o ex

r sources . However , beca

u o f non-stochasti c effects exceptional case s o

f work

gone radiodiagnosi s o r

r; in g heavy irradiatio n o

f p : whos e wor

k woul dinvolv ure of thos e parts , th e shoul db e reviewedby th e authority
. Implications for

non-stoc (94 ) A s alread y stated , recommende ddose-equi \ limitatio n o

f stochastic ef

; contribution s fro mnatur : or frommedica

l expos iCRP ance s in whic h judgmen t

wil l hav e ise d a s t o whethe r

th e componen t ; d natura l radiatio n shoul do r b e subjec t t o th e Commission' s •e d systemo f dos e limitation , houl db e emphasize dmoreover e premis e tha t

th e frequenc y of ffects i s linearl y proportiona l t o ^ived , suc h harma s ma

y b e cause d radiatio n coul db e regarde da s t of , an dsimply additiv e to , th e iar mtha t ma y b e cause dby any of ade practice s involvin g radiatio n ) which th e Commission' s limit s hi s sense , regional variation s i n iatio n ar e regarde da s involvin g a in g variatio n in detrimen t

in jus t t y as , for example , regional varia

eorological condition s o r

volcani c olv e difference s in th e risk

of harm : areas . O n thi s basi s ther e i s n o • difference s in natura l radiatio n c t acceptabl e level s o

f man-mad e n y more tha n difference s i

n othe r s shoul ddo
.

oosures of

patients and ilent limits hes e recommendation s "medica l refer s t o th e intentiona l exposure : for diagnosti c an dtherapeuti c n dt o th e exposure s resultin g fro m i l replacement

o f bod y organ s o r z.g. b y hear t pump s an dcardia c s)
. I t applie s t o exposure s : d by medica

l an dparamedical I t doe s no t refe r t o th e irradiatio n involve din th e administratio n of posure s t o patients , no r

t o th e o f on e patien t

b y another
. ica l exposure is , i

n general , subjec t th e Commission' s syste

mof dos e tha t is : unnecessar

y exposure s avoided ; necessar

y exposure s jstifiabl e in term s of

benefit s tha t Hherwis e hav e bee

n received ; an d actually administere dshoul db e RECOMMENDATION S O F TH E ICR P 1 9 limited t o th e minimu mamoun t consisten t vith th e medica

l benefi t t o th e individua l patient
. Th e individual receivin g th e exposur e h himsel f th e direc t

recipient o f th e benefi t resultin g fromth e procedure
. Fo r thi s reaso n i t i s no t appropriat e t o appl y th e quantitativ e value s of th e Commission' s recommende d dose-equivalent

limit s t o medica

l exposures . Wit h certai n medica

l exposure s aver

y muc h highe r leve l o f ris k ma y in fac t b e justifie db y the benefi t derive dtha n b

y th e leve l judge d b y th e Commissio n t o b e appropriat e for occu pational exposure o r

for exposure o

f member s ofth e public
. (93 ) It ha s already been indicate di n para grap h 8 9 tha t

th e Commission' s recom mended dose-equivalen t

limit s ar e intende d : o r plannin g purpose s an drefe r t o tha t com ponent 'o f ris k resultin g fromaparticula r practic e t o which radiatio n protectio n applies
. Unde r th e assumptio n o f

linearit y th e risk i ro msuc h apractic e i s unaffecte d by th e risk s "ro m othe r sources , an di t

i s therefor e justifi

able t o consider

separatel y th e dose s receive d iro msuc h practice s fromth e dose s acquire d fro mmedica l exposure . I n vie

w of th e con sideration s detaile din paragrap h 92 , th e Commissio n consider s tha t radiatio n dose s resultin g frommedica

l exposure s shoul dno t influenc e any o f

th e procedure s of

dos e limitatio n applie dt o exposure s fro mothe r sources . However , becaus e o f th e possibilit

y o f non-stochasti c effect s developin g i n th e exceptiona

l case s o f worker s wh o hav e under

gon e radiodiagnosi s o r

radiotherap y involv

in g heav y irradiatio n of

part of th e body , an d whos e wor k woul dinvolv e substantia l expos ur e o f thos e parts , th e workin g situatio n shoul db e reviewedb

y th e competen t

medical authority
. Implications for

non-stochastic effects (94) A s already stated , th e Commission' s recommende ddose-equivalen t limit s for

th e limitatio n of

stochastic effect s d o no t

appl y t o contribution s fromnatura l radiatio n source s or fro mmedica

l exposure . However , th e questio n o f non-stochastic effect s merit s con sideration
. (95 ) Whe n exposur e i s limite db y considera

tio n o f stochasti c effects , i t

i s unlikel y tha t

th e additio n o f

occupationa l exposure s an d norma l medical o r

natura l radiatio n expos ure s woul d caus e atota l dos e equivalen t tha t woul d b e near

threshol dvalue s of

an y harm

fu l non-stochasti c effect
. Although , in principle , contribution s t o th e dos e equivalentfro mall

source s (i.e
. als o from medica l source s an dnorma l natura l back

ground ) shoul db e adde di n assessin g th e like

lihoo do f non-stochasti c damag e occurring , th e Commissio n consider s tha t in practic e i t

i s no tnecessar

y tha t thi s shoul db e done
. Hig h dose s fro m natura l radiatio n source s woul d onl y b e expecte dt o occur.unde r th e special condition s mentione di n paragrap h 8 9 an d shoul d i n an y cas e the n b e include dunde r th e dose-equivalentlimit s t o th e exten t tha t th e elevate d exposure s ar e subjec t t o huma n control . I n th e cas e of

hig h medica

l exposure s (e.g
. i n radiotherapy ) i t

woul db e th e dose s from thes e exposure s tha t woul d dominate , an d th e consideratio n of

possibl e risk s of

non stochasti c effect s (e.g
. t o th e len s of th e eye ) woul d b e par t

of th e medica

l consideration s in th e treatmen

to f th e patient , rathe r

tha n th e tas k o f thos e responsibl e for

radiatio n protectio n i n general
. Dose-equivalent

limits for workers (96 ) A s state din paragrap h 77 , th e Com

mission' s recommende ddose-equivalen t limit s fo r occupationa l exposur e hav e bee n i n effec tfo r ove r

2 0 years . I n vie

w of th e emphasi s tha

tth e Commissio n place s o n ris k estimations , i t

believe s i t appropriat e t o asses s th e level s o f

risk tha t ar e associate dwit

h it s dose-equivalentlimits
. Th e Commissio n believe s tha

tfor th e foreseeabl e futur e avali d metho d fo r judgin g th e acceptability of th e level o f ris k i n radiatio n wor

k i s by comparin g thi s risk wit

h tha t for othe r occupation s recognize da s havin g high standard s of safety , whic h ar e generall y considere dt o b e thos e inP.2 7

2 0 RECOMMENDATION S O F TH E ICRP which th e averag e annual mortalit y du e t o occupational hazard s doe s no t excee d10 -4 *
. I n mos t occupations , fatalities , whether du e t o accident s or

disease , ar e accompanie db y a much large

r numbe r o f les s sever

e conse quences . Radiatio n exposure , o n th e othe r hand , a t level s impose dby adherenc e t o recommende ddose-equivalent limits , i s ex pecte dt o caus e ver

y fe w injurie s o r

illnesse s in expose dworker s othe r

than any malignan t disease s whic

h ma y b e induced
. In assessin g th e implicatio n o

f dose-equivalent

limit s therefore th e Commissio n believe s that th e calculate drat e at

whic h fatal malignancie s •migh t be induce db

y occupational exposur

e t o radiatio n shoul di

n an y cas e no t

excee dth e occupational fatalit

y rat e o f industrie s recog - ' nizeda s havin g high standard s o f safety
. (97 ) Other criteri athan fatalit

y rate s coul d b e use di n ensurin g tha

t radiatio n exposure , a s controlle db

y recommende ddose-equivalent limits , involve s n o greater hazar dthan i n othe r saf e industries
. Ideally , accoun t shoul d b e take n o

f al l component s of

th e harm , o r detriment , involve

di n th e variou s occupation s —includin g th e su

mo f all accidents , illnesses , geneti c defects an d fatalitie s involved , a s wel l a s th e aaxietie s of

worker s o r

thei r familie s abou t th e hazard s o r

condition s o f

wor k i n different industries
. A s afirs t

approximatio n i t ca n b e state dtha t

a n assessmen

t base donly on th e mortalit

y criterio n ca

n b e regarde da s •conservativ e sinc e experienc e ha s shown that th e non-fatal effect s o

f irradiatio n ar e much les s frequen

t than th e non-fatal effects encountere di n othe r

saf e occupations
. However , th e summatio n an dcompariso n of th e divers e contribution s t o tota l detrimen t ar e difficult

t o make o

n a n objectiv e basis
. (98 ) Account

ca n b e take n of

som e component s o

f disabilit y b y estimatin g th e averag e amoun t

of tim e los t (e.g
. pe r worke r year ) fro mful l activity—whethe

r fromacci

dents , industria l diseas e or , i n th e extrem e case , b y deat h fro moccupational causes . A revie w o f th e problem s involve di n developin g any "Inde x of Harm " o n thi s basi s i s give n i n areport o n thi s topi c bein g prepare dfor th e Commission ; however , n o such criterio n ca n b e regarde da s more tha n indicativ e o f broa d difference s in risk
. I

t shoul db e mentioned , however , tha t

an accidental deat

h appear s t o involv e a n averag e los s o f

abou t 3 0 year s of lif e i n man y industries , an dt o b e associate d wit h a n approximatel y equal tota l los s of workin g tim e fro mindustria l accidents
. A fatal malignanc y induce db y occupationa l exposur e t o radiatio n woul db e expecte dt o involv e th e los s o f

abou t 1 0 year s of

life , owing t o th e lon g latenc y in th e development o f suc h acondition , withou t

appreciabl e associate dtim

e los s fromaccidents
. (99 ) When makin g comparison s wit h othe r saf e occupations , i t

shoul db e realise dtha t

th e leve l o f ris k representativ e of

asaf e occupa tio n relate s t o th e average ris k for al l worker s .i n tha t occupation , th e ris k

for individual worker s varyin g wit

h thei r jo b an dbein g distribute daroun dthi s average . A simila r distributio n of

individual risks als o occur s i n radiatio n work ; i

n man y case s of

occupationa l .exposur e wher e th e Commission' s syste

mo f dosehmitatio n ha s been applied , th e resultan t annua l averag e dos e equivalen t i s n o greate r than one-tent

h o f th e annua l limi t

. t Therefor e th e applicatio n of

adose-equivalen t

limi t pro vide s much bette r

protectio n fo r

th e averag e worke r i n th e grou p tha n tha t

correspondin g t o th e limit
. (100 ) I n th e cas e o

f unifor mexposure o

f th e whole body , i

n circumstance s wher

e th e Com

mission' s recommendations , includin g th e annual dose-equivalent

limi t o f 5 0 mSv , hav e bee n applied , th e distributio n o f th e annua l dos e equivalent s i

n larg e occupationa l group s ha s been show n ver

y commonl y t o fit

alog

norma l function , wit

h an arithmeti c mea

n of abou t 5 mSv , an dwit

h ver y fe w value s approachin g th e limit
. Th e applicatio n of th e ris k factor s give

n i n paragraph s 40-6 0 t o th e abov e mea

n dos e indicate s tha t

th e averag e risk in thes e radiatio n occupation s i s com - •Se e th e Commission' s repor to n Problem s Involve d i n Developin g a n Inde x ofHar m (i n preparation) . TSe e Annex. E o f

th e 197 7 Repor to f

th e Unite d Nation s Scientifi c Committe e o n th e Effect s o f Atomi c Radiation . parabl e wit h th e averag e industrie s (bu t

se e als o pa r (101 ) Th e Commissio i limit s ar e primaril y i

n adequat e protectio n eve

n expose dindividuals , i n worker s wh o ar e expose equivalent limit s are unli l dose s each yea

r o f thei r o c i t woul db e thei r

expei equivalent tha t woul di ; individua l risk
. I n thi : comparabl e wit

h individu ; randoml y t o higher

risk s tions
. Exposure s consiste ; wouldb e comparabl e wit

h higher-than-averag e ris k

i fo r certai n individual s in n tries
. (102) However , i

f th e e : i n any particular

occup planned s o tha t alarg e f receiveddbs e equivalent s th e annua l limit , th e aver ; ris e substantiall y abov e o

n There woul dthu s b e ac o th e averag e risk , eve

n tho u equivalent limi t wa s no t individual worker
. Long- c o f aconsiderabl e proporti t or nea r th e dose-equivale n b e acceptabl e i

f acarefu l c

c ha dshow n tha t

th e hi g woul db e justified
. Recommended

dose-equ Th e Commission' s rec c intende dt o preven t

non an dt o limi t

th e occur r effect s t o an acceptabl e U sio n believe s tha t

non-st o b e prevente dby applyin g limitof0.5Sv(50rem)i n except th e lens , for

whic recommend s alimi t

of 0
. year . Thes e limit s app i whethe r th e tissue s ar e together wit h othe r org ;P.2 8

RECOMMENDATION S O F TH E ICR P o f Harm " o n thi s basi s i s give n in thi s topi c bein g prepare dfor th e i ; however , n o suc h criterio n ca n a s more tha n indicativ e of

broa d i n risk. I t shoul db e mentioned , a t a n accidental deat

h appear s t o verag e los s of

abou t 3 0 year s o f industries , an dt o b e associate d proximatel y equa l tota l los s of

. e fromindustria l accidents
. A lanc y induce db

y occupationa l radiatio n woul db e expecte dt o los s of abou t 1 0 year s of

life ,

. • lon g latenc y i n th e development condition , withou t

appreciabl e m e los s fromaccidents , i makin g comparison s wit

h other , ions , i t shoul db e realise dtha t

th e representativ e o f

asaf e occupa*

- o th e averag e ris k

for al l worker s ipation , th e risk

for individual ying wit h thei r jo b an dbein g aroun dthi s average . A simila r o f individual risk s als o occur s in Tk ; i n many case s o

f occupationa l •er e th e Commission' s systemof on ha s bee n applied , th e resultan t tg e dos e equivalen t

i s n o greater t h of th e annua l limit. t

Therefor e o n o f adose-equivalen t

limit pro bette r protectio n for

th e averag e e grou p tha n tha t

correspondin g

e cas e o f uniformexposure o

f th e i n circumstance s wher

e th e Com

commendations , includin g th e equivalent limi t o f 5 0 mSv , hav e i , th e distributio n o

f th e annua l ents in larg e occupationa l group s >w n ver y commonl y t o fit

alog

tion , wit h a n arithmeti c mea

n of iv , an dwit

h ver y fe w value s the limit
. Th e applicatio n o f th e ;ive n i n paragraph s 40-6 0 to th e dos e indicate s tha t

th e averag e radiatio n occupation s i s com - \ o f Harm'(i n preparation) . : c o n th e iilTcct s o f Atomi c Radiation

. p:;rabl e wit h th e averag e ris k

in othe r saf e industrie s (bu t

see als o paragrap h 29)
. <;01 ) Th e Commission' s dose-equivalent limit s ar e primaril y intende dt o ensure adequate protectio n eve

n for th e mos t highly expose d individuals
. I n man

y occupation s •.•••acker s wh o ar e expose dnea

r th e dose

euuivalen t limit s ar e unlikel y t o receiv e suc h dose s eac h yea

r o f thei r occupationa l lif

e an d i t woul db e thei r

expecte dlifetime dos e equivalent that woul dindicat e thei r

tota l individua l risk
. In thi s sens e they ar e comparabl e wit

h individual s wh o ar e expose d randoml y t o higher

risk s in "safe " occupa tions
. Exposure s consistentl y nea r th e limit s woul db e comparabl e wit

h asituatio n wher

e a uigher-than-averag e ris k

ha s been identifie d

. .fa r certai n individual s in non-radiatio n indus

-

. . tries
. 1102 ) However , i

f th e exposure o f

worker s i n an y particular

occupatio n wer

e t o b e I'lanned s o tha t alarg e fractio n of

worker s receive ddos e equivalent s which approache d ih e annua l limit , th e averag e exposure coul d i :s e substantiall y abov e one-tent h o f th e limit
. Ther e woul dthu s b e acorrespondin g ris e in i h e averag e risk , eve

n thoug h th e annua l dose

equivalen t limi t wa s no t exceede dby any individua l worker
. Long-continue dexposure o f aconsiderabl e proportio n o f th e worker s at o r nea r th e dose-equivalen t

limit s woul donl y be acceptabl e i

f acarefu l cost-benefi t

analysi s ha dshow n tha t

th e highe

r resultan t ris k woul db e justified
. Recommended

dose-equivalent

limits. (103 ) Th e Commission' s recommendation s ar e intende dt o prevent

non-stochasti c effect s andt o limit

th e occurrenc e of

stochasti c effects t o a

n acceptabl e level
. Th e Commis

sion believe s tha t

non-stochasti c effect s wil l be prevente db

y applyin g adose-equivalen t limi t of 0. 5 Sv (5 0 rem) i

n ayea r t o al l tissue s excep t th e lens , fo

r which th e Commissio n recommend s alimit

of 0. 3 S v (3C

f rem) i n a year . Thes e limit s appl y irrespectiv e of whethe r th e tissue s ar e expose dsingl y o r togethe r wit h othe r organs , an dthey ar e intende dt o constrai n any exposure tha t fulfil s th e limitatio n o f

stochasti c effect s (see paragraph s 104-110)
. (104 ) Fo r stochasti c effect s th e Commis

sion' s recommende ddos e limitatio n i s base d o n th e principl e tha t

th e ris k shoul db e equa

l whether th e whol e body i s irradiate duniform

l y or whethe r there i s non-uniformirradiation
. Thi s conditio n will b e met

i f 

### Z T 

### w T 

### H T 

### ZH wb,i » where , w T i s aweightin g facto r

representin g th e proportio n o f

th e stochasti c ris k

resultin g fromtissu e (T) t o th e tota l risk , when th e whol e body i s irradiate duniformly , HT is th e annua l dos e equivalen t

in tissu e (7V)

, //«,b. i i s th e recommende dannua l dose-equivalent limi t for uniformirradiatio n of

th e whol e body , namel y 5 0 mS v (5 rem)
. (105 ) Th e value s o f

w T recommende dby th e Commissio n ar e show n below :
Tissue Gonad s Breas t Red bon e marro w Lun g Thyroi d Bon e surface s Remainde r w T 0.2 5 0.1 5 0.1 2 0.1 2 0.0 3 0.0 3 0.3 0 Th e valu e of

w T for th e remainin g tissue s require s furthe r

clarification
. Fo r

th e reason s state di n paragraph s 5 8 an d5 9 th e Commissio n recommend s tha t

avalu e of

w T = 0.0 6 i s applicabl e t o eac h o

f th e fiv e organ s o r

tissue s of th e remainde r

receivin g th e highes t

dos e equivalents , an dtha t

th e exposure o

f al l othe r remainin g tissue s ca

n b e neglected
. (When th e gastro-intestina l trac t

i s irradiated , th e stomach , smal l intestine , uppe r larg e intestin e an dlowe r larg e intestin e ar e treate da s four separateorgans. ) (106 ) It i s recognize dtha t

th e ris k associate d wit h agive n exposure wil

l var y wit h th e ag e an d se x of th e individual exposed
. However , th e value s of w r give n i n paragrap h 10

5 ar e recom mende da s appropriat e for th e protectio n o

fP.2 9

2 2 RECOMMENDATION S O F TH E ICR P any worker , regardles s o

f thes e source s o f variability(seealsoparagraph38)
. (107 ) Th e value s of

M Y presente di

n para grap h 10 5 ar e intende da s guidanc e fo r thos e concerne dwit

h calculatin g secondar

y an d derive dlimit s (see sectio n F)
. I n particular , they ar e usedb

y ICR P Committe e 2 i

n calcu

latin g value s o f

annua l limit s of

intake (ALI ) for radionuclides , which take account o f th e dos e equivalent

i n eac h tissue
. I n practica l situations , however , i

t wil l usuall y suffic e t o us e th e tw o secondar

y limit s tha t

ar e applic

abl e t o external an dinterna l exposure , namely , th e limi t

t o th e dose-equivalent

inde x H, (see paragrap h 108) an dAL I (see para grap h 109)
. (108 ) Wit h external

exposures t o penetrat
ing radiation , o n thos e occasion s whe n infor

matio n i s lackin g concernin g th e actual distributio n o

f dos e equivalent

in th e body , i

* i s possibl e t o asses s th e maximum valu e o f dos e equivalent

tha t woul doccur

in a3 0 c m sphere (th e deep dose-equivalent index , H,)*. Th e limitatio n of

th e dose-equivalent

index t o an annua l valu e of

5 0 mS v woul dafforda leve l o f protectio n tha

t woul db e a

t leas t a s goo da s tha t

provide db

y th e metho drecom mende d in paragrap h 104
. (109 ) Wit h internal exposure resultin g from th e intak e of

radionuclide s protectio n ca n b e base don annua l limit s o

f intak e (ALI)
. Thes e ar e calculate db y ICR P Committe e 2
. fro m knowledg e of

th e variou s organ committe d dos e equivalent s pe

r uni t intake , b y applica

tio n o f th e principle s discusse din paragraph s 10 4 an d105 ; suc h exposure s ar e als o subjec t t o th e limit s for

non-stochasti c effect s give n i n paragrap h 103
. (110) When external an dinterna l exposure s are receive dtogether , th e Commission' s recommende ddos e limitatio n for stochasti c effect s wil l no t b e exceededif

: "wb. L 'i.i.

where , // , i s th e annual dose-equivalent index , /7 w b Li s th e annual dose-equivalent limit , lji s th e annual intake of

radionuclid e j , I

JL i s th e annua l limi t

of intak e for

radionuclid e j
. (111 ) Althoug h th e Commissio n n o longe r propose s separat e annua l dose-equivalent limit s for individual tissue s an dorgan s irradi

ate dsingly , th e implie dvalue s o f suc h limit s ma y b e obtained , i

f required , b

y dividin g th e dose-equivalent

limi t H^.L (5 0 mS v in ayear

) b y th e relevan

t valu e o f WT. Suc h value s woul d b e subjec t

t o th e limits , base do n non stochasti c effects , give

n in paragrap h 103
. (112) It shoul db e recognize dtha t

th e limit s hav e bee n derive dfor

applicatio n in averag e situations , for

all adul t age s an dfor

both sexe s an dwithou t

regardt o individual circum

stance s which might

enhanc e th e risk
. Th e Commissio n believe s that , for example , any variatio n in risk

wit h ag e will no t

influenc e th e tota l ris k fromalifetime exposure unles s th e exposur e i s limite dt o aspecia

l group . Addi

tional precaution s an d dos e limitation s ma y b e necessary , however , t o limi t th e irradiatio n o

f an embry o o r

foetu s i n th e cas e of

occupational exposure o f

pregnan t wome n (se e paragraph s 115andll6)
. Planned special exposures. (113 ) Situation s ma y occu r infrequentl y durin g normal operation s whe

n i t ma y b e necessar

y t o permi t afe w worker s t o receiv e dos e equivalent s i n exces s o f th e recommende dlimits
. I n suc h circumstance s external exposure s o r intake s o f radioactiv e materia l ma y b e permitte d provide dth e dose-equivalen t commitment doe s no t excee dtwic e th e relevan t

annua l limit in an y singl e event , and , i n alifetime , fiv e time s thi s limit
. Th e Commissio n wishe s t c

•Internationa l Commissio n o n Radiaiio n Unit s andMeasurements , Th e Conceptua l Basi s fo r the Deicrminalio n o f Dos e Equivalent , tCRU Report 25, International Commission on Radiaiio n Unil s an dMeasurements , Washington , 1976
. emphasiz e tha t external e o f thi s magnitud e ar e c alternativ e techniques , w

l suc h exposure of

w o unavailabl e or

impra c paragrap h 171)
. (114 ) Planne dspecia

l e> b e permitte di

f th e wo r receivedabnorma l expos u equivalent s i n exces s of

fi\ annua l limit
. Planne d shoul dno t

b e permitte df

< ductiv e capacity
. Dos e e

c fro mplanne dspecia

l e x recorde dwit

h thos e fro

n but any exces s ove

r th e li m paragraph s 10

3 et seq. s i constitut e areaso n fo

r e fro mhi s usual occupatio
. emergency exposure s ar e c G)
. Occupational

exposure x ductive capacity. (115 ) reproductiv e capacit

y a exposedunde r

th e limit s paragrap h 108 , an dwhe : receiveda t an approximat e unlikely tha t

an y embry o c tha n 5 mS v durin g th e pregnancy . Havin g t circumstance s i

n which su

i occur , th e Commissio n procedure wil

l provid e a

j tio n durin g th e essential genesis
. Occupational

exposure q (116) I t i s likely tha t

any i than 2 months ' duratio n recognize dby th e woma i physician
. Fo r

reason s des e 65 , th e Commissio n recor

r pregnanc y ha s bee n diagn c shoul db e mad e t o ensur e t l continu e t o wor

k onl y i n V \ B , specifie di n paragrap h 1 1ICRP

" wb . L'j, L s th e annua l dose-equivalent index , h e annual dose-equivalent limit , -.ua l intak e o f radionuclid e j , I

jt L i s limit of intak e fo r radionuclid e j
. rhough th e Commissio n n o longe r separat e annua l dose-equivalent tdividual tissue s an dorgan s irradi

-
, th e implie dvalue s o

f suc h limit s ained , i f required , b

y dividin g th e alen t limi t //wb,/
. (5 0 mS v in ayear) an t valu e o f WT. Such value s woul d t o th e limits , base do n non effects , give

n in paragrap h 103
. houl db e recognize dtha t

th e limit s derivedfo r

applicatio n in average , fo r al l adul t age s an dfor

bot h sexe s - ut regar dt o individual circum

ic h might enhanc e th e risk
. Th e > n believe s that , for

example , an y i risk wit h ag e wil l no t influenc e th e o malifetime exposure unles s th e limite dt o aspecia

l group . Addi

tution s an d dos e limitation s ma y b e however , t o limi t

th e irradiatio n of ) r foetu s i n th e cas e o

f occupationa l 'pregnan t women (see paragraph s special exposures. (113 ) Situation s r infrequentl y durin g norma l whe n i t ma y b e necessar

y t o permi t :ers t o receiv e dos e equivalent s i n h e recommende dlimits
. I n suc h ce s external exposure s o r

intake s tiv e materia l ma

y b e permitte d h e dose-equivalen t

commitmen t :ee dtwic e th e relevan t

annua l limit ,l e event , and , in alifetime , fiv e iimit
. Th e Commissio n wishe s t o

: Conceptua l Basi s lo r th e Determinatio n n Radiatio n Unit s an d Measurements , RECOMMENDATION S O F TH E ICR P 2 3 emphasiz e tha t

external exposure s o r

intake s o l thi s magnitud e ar e only justifie dwhe n aiternativ e techniques , which d o no t involv e suc h exposure o f

workers , ar e either unavailabl e or

impracticabl e (see als o paragrap h 171)
. (114) Planne dspecia

l exposure s shoul dno t b o permitte di

f th e worke r

ha s previousl y receive dabnorma l exposure s resultin g in dos e •-ouivalents i

n exces s of

fiv e time s th e relevan t annua l limit
. Planne dspecia l exposure s .houl d no t b e permitte dfor

women of

repro ductiv e capacity
. Dos e equivalent s resultin g iro mplanne dspecial exposure s shoul db e secorded wit

h thos e fro musual exposures , bu t any exces s ove

r th e limit s recommende din paragraph s 10

3 et seq. shoul dno t

b y itself constitut e areaso n fo r

excludin g aworke r fro mhi s usual occupation
. (Accidental an d emergency exposure s ar e discusse di n sectio n G)
. Occupational

exposure of

women of

reproductive capacity. (115 ) When women o f reproductiv e capacit

y ar e occupationall y expose dunde r th e limit s recommende din paragrap h 108 , an dwhen thi s exposure i s receive dat a n approximatel y regula

r rate , i t i s unlikel y tha t any embry o coul dreceiv e more tha n 5 mS v durin g th e firs t 2 month s of pregnancy . Havin g regardt o th e circumstance s in which suc h exposure s coul d occur , th e Commissio n believe s tha t thi s procedur e wil l provid e appropriat e protec
tion durin g th e essential perio do f organo genesis
. Occupational

exposure of

pregnant women. (116 ) I t i s likely tha t

any pregnanc y of

more tha n 2 months ' duratio n woul dhav e been recognizedb

y th e woma

n herself o r by a physician
. Fo r

reason s describe di

n paragrap h 65 , th e Commissio n recommend s that , whe n pregnanc y ha s been diagnosed , arrangement s shoul db e mad e t o ensur e tha t th e woma

n ca n continu e t o wor

k only i n Workin g Conditio n B , specifie di

n paragrap h 161
. Dose-equivalent limits for individual

members of the public. (117 ) Radiatio n risk s ar e a ver y mino r fractio n of

th e tota l numbe r

o f environmenta l hazard s t o whic h member s o f th e publi c ar e exposed
. I t seem s reasonabl e therefor e t o conside r

th e magnitud e o f

radia

tio n risk s t o th e general publi c i n th e light o f th e publi c acceptanc e o f

othe r risk s of every da y life
. Thi s acceptanc e (when relate dt o risk s tha t coul dno t

b e reduce do r

avoide d entirely ) i s motivate db y th e benefit s tha t woul dno t otherwis e b e received , b y a n assess ment of th e social cos t

o f achievin g apossibl e reductio n o f

risk, o r b y a n implici t

judgmen t tha t th e risk i s negligible
. (118 ) Th e acceptabl e leve l of ris k for stochasti c phenomen afor member s o f

th e general publi c ma

y b e inferre dfro mconsider

atio n o f risks tha t a n individua l can modif

y t o onl y asmal l degre e an dwhich , like radiatio n safety , ma

y b e regulate db y nationa l ordin

ance . A n exampl e o f

suc h risk s i s tha t

of usin g publi c transport
. Fro mareview of availabl e informatio n relate dt o risk s regularl y accepte d' in everyda y life , i t can b e conclude dtha t

th e leve l of acceptability fo r

fata l risks t o th e general publi c i s a n orde r

o f magnitud e lowe

r than for occupationa l risks. O n thi s basis , a ris k i n th e rang e o f

IO - 6 t o IO" 5 per

yea r woul d b e likely t o b e acceptabl e t o an y individua l membe r o f th e public
. (119 ) Th e assumptio n o f

atota l ris k

of th e orde r of 10" 2 Sv 1 (se e paragrap h 60 ) woul d imply th e restrictio n o f

th e lifetime dos e t o th e individual member

o f th e publi c t o avalu e tha t woul dcorrespon dt o 1 mS v pe r yea r o f life-lon g whol e bod y exposure . Fo r th e reason s given i n th e followin g paragraphs , th e Commission' s recommende dwhol e body dose-equivalen t

limi t o f 5 mS v (0. 5 rem ) in a year , a s applie dt o critica l groups , ha s been foun dt o provid e thi s degre e o f safet y an dth e Commissio n recommend s it s continue dus e unde r th e condition s specifie di n paragraph s 120-128
. (120) Th e applicatio n o f

a n annua l dose

equivalen t limi t o f 5 mS v t o individua l member s o f

th e publi c i s likel y t o resul t i nP.3 1

2 4 RECOMMENDATION S O F TH E ICRP averag e dos e equivalent s of les s than 0. 5 mSv , provide dtha t

th e practice s exposin g th e publi c ar e fe

w an dcaus e littl e exposure outsid e th e critica l group s (se e paragrap h 85)
. When applyin g th e dose-equivalent limit for member s of

th e public , consideratio n mus t b e give n t o th e possibilit

y tha t some individual s ma y belon g t o more than on e critical group , l n fact , du e t o th e maximizin g assumption s usuall y mad e i

n selectin g critical groups , th e dose s actuall y receive dby th e mos t highly expose dindividual s wil

l in mos t case s b e considerabl y lowe

r than th e dose s postulate d for th e critical group . (121 ) Th e actua l valu e o

f th e averag e dos e depend s upo n both th e resul t of th e optimiza

tio n proces s of

alarg e numbe r

of justifie d practice s causin g radiatio n exposure s an dth e valu e selecte dt o limit

th e individual doses
. I

f at som e time in th e future th e combine d exposure resultin g fromoptimize dexposure s resulte di n averag e dos e equivalent s highe r tha n 1 mS v i n ayear , th e situatio n migh t stil l b e justifiable , eve

n thoug h th e averag e risk fo r member s of

th e publi c woul db e highe r than th e rang e 10 - * t o 10~

5 pe r year . (122) In some case s optimization , which coul db e th e overridin g protectio n criterion , wil l necessitate amor e realisti c selectio n o f th e critica l group , becaus e t o overestimate th e ris k woul dintroduc e abia s whic h woul d invalidate th e optimization
. In thes e cases , th e dose-equivalen t

limi t t o individual member s of th e public , referre dt o in paragrap h 120 , woul dstil l adequatel y restric t th e averag e dos e equivalent , bu t

th e fe w individual s expose dt o th e dose-equivalent limit coul dru n aris k in th e rang e o

f 10 - 5 t o 10 - 4 pe

r year . Thi s annua l ris k

woul dthe n b e on e orde r o f magnitud e higher

tha n th e ris k

rang e quote d i n paragrap h 118
. Sinc e exposure s at th e dose

equivalen t limi t ar e no t likely t o b e repeate d ove r man y years , however , a

n adequat e restrictio n o f

th e life-tim

e dos e i s stil l likely t o b e achieved
. I n any rar e case s wher e th e dose s t o afe w individual s wer

e actuall y foun dt o b e receive da t

high rate s ove

r prolonge dperiods , i t woul db e pruden t

t o take measure s t o restric t thei r life-tim e dos e a s implie di n paragrap h 119
. (123 ) In suc h cases , wher

e optimizatio n i s th e decidin g protectio n criterio n an dwhere critical group s ar e selecte do n th e basi s o f realisti c assumptions , i

t woul db e appropriat e t o us e a s aboundary conditio n o f an y singl e optimizatio n proces s a

n individual dos e limit

atio n suc h a s indicate di n paragrap h 122
. Eve n th e fe w individual s wh o woul dactuall y receiv e dose s of

thi s magnitud e over

alon g perio do f tim e woul dno t

b e subjec t

t o risk s appreciabl y abov e th e leve l tha t i s generall y considere dacceptabl e (se

e paragrap h 118)
. (124) I n mos t

applications , however , administrativ e plannin g i s base do n opera tional limit s derive dfromver y crud e cost
effectivenes s consideration s o f protectiv e measure s an dquit e conservativ e estimate s o f th e resultin g dose s i

n critical groups . Fo r

suc h plannin g i t

i s usuall y quit e appropriat e t o asses s th e dose s in th e critical grou p in relatio n t o th e dose-equivalent

limi t of 5 mS v i n ayear , an dth e Commissio n ha s foun dn o reaso n t o recommen dachang e i

n thi s practice
. Th e mai n reaso n fo

r thi s decisio n i s tha t

th e Com

mission' s systemof

dos e limitation , wit

h th e dose-equivalent

limi t of 5 mS v i n ayear , i s foun dt o provid e th e necessar y degre e c f safety , unde r

th e boundar y condition s state d i n paragraph s 120-123 , an dtha t achang e i

n th e upper limit woul dno t

b e o f th e same importanc e fromth e radiatio n protectio n point of vie w a s th e rigorou s applicatio n o f th e principl e o

f keepin g al l dose s a s lo w a s i s reasonabl y achievable
. (125 ) Fo r non-homogeneou s exposure. " wit h organ dose s H

T , th e limitatio n conditio n i s Y. T

W THT ^H'^L , where/^,; , L

isthedose

equivalent limit fo r uniformirradiatio n o f

th e whol e body for

amember

of th e public
. Du e t o different

ag e distribution s whe n member s o f th e publi c ar e irradiated , th e risk s wil l no t b e quit e th e sam

e a s fo r occupationa l exposures . Th e relative risks , however , wil l diffe r bu t littl e an dth e Commissio n ha s no t foun dth e difference s significant enoug h t o recommen daseparat e se t o f weightin g factors , differen t fro mt h i n paragrap h 10

5 (se e als o (126 ) In orde r

t o prev e (issu e fromreceivin g at o contribut e significantl y : non-stochasti c effects , a : dose-equivalent

limit of 5 ' Thi s limit i s considera l correspondin g limit s re a ventio n of non-stochasti c pationa l exposure . Th e i

t tha t th e longe r

expos u practical difficultie s in c exposure fromal

l sourc e threshol ddose s for

no t being reached
. Th e w

c recommende di

n paragrar provid e th e necessar

y lim i stochasti c effects , bu t

th e neededfor th e ski n an dth

e (127 ) In th e calculatio n len t incurre db

y member s intake o f radionuclides , take n o f difference s i n or g characteristic s of

ehild n difference s ma

y b e foun d tas k grou p o n Refer

e Publication 23). (128 ) A s wit

h worker s ( a n increas e i n th e averag e t th e publi c coul dresul t

fro r i n th e numbe r

of source s thoug h eac h satisfactoril y justificatio n an doptim i graph s 68-76 ) an dcaused ; th e recommende dlimii regional authoritie s sho e unde r surveillanc e th e sep ; fromal l practice s t o th e a th e whol e populatio n s o a singl e sourc e o r

pract k unjustifie damoun t

t o the ; that n o individua l receive s aresul t of membershi p o

f i groups . Exposure of

populations (129 ) I n it s previou s re cICR P m e dos e a s implie din paragrap h
such cases , where optimizatio n i s g protectio n criterio n an dwher e up s ar e selecte do n th e basi s o f umptions , i

t woul db e appropriat e boundary conditio n of

any singl e >. n proces s an individual dos e limit

as indicate din paragrap h 122
. • w individual s wh o woul dactuall y e s of thi s magnitud e ove

r alon g im e woul dno t

b e subjec t

t o risk s / abov e th e leve

l tha t i s generall y acceptabl e (se e paragrap h 118)
. t mos t applications , however , :ive plannin g i s base do n opera - : s derive dfro mver

y crud e cost
s s consideration s o f

protectiv e n dquit e conservativ e estimate s o f g dose s i n critical groups . Fo r suc h

. i s usuall y quit e appropriat e t o ose s in th e critical grou p i

n relatio n equivalent limit o f 5 mS v i n ayear , mmissio n ha s foun dn o reaso n t o 1 achang e in thi s practice
. Th e a for thi s decisio n i s tha t

th e Com

yste mof dos e limitation , wit

h th e tlen t limi t of 5 mS v i n ayear , i s provid e th e necessar

y degre e of e r th e boundary condition s state d ';h s 120-123 , an dtha t

achang e i

n limi t woul dno t

b e o f th e same fromth e radiatio n protectio n : w a s th e rigorou s applicatio n of e of keepin g al l dose s a s lo

w a s i s achievable
. > r non-homogeneou s exposure s dose s H

T , th e limitatio n conditio n ^ H'wb.Lt where H^. L

isthedose

imit fo r unifor mirradiatio n o

f th e fo r amembe r of th e public
. Du e ag e distribution s whe

n member s : c ar e irradiated , th e risk s wil l no t the same a s fo

r occupationa l Th e relative risks , however , wil l ittl e an dth e Commissio n ha s no t difference s significant

enoug h t o 1 aseparat e se

t o f weightin g RECOMMENDATION S O F TH E ICR P 2 5 factors , differen t

fromth e value s of

w T given ir : paragrap h 10

5 (seeals o paragraph60)
. : 126 ) In orde r t o preven t

any on e organ or • u e fromreceivin g atota l dos e which coul d ^•r.tribute significantl y t o th e inductio n o f non-stochasti c effects , an overridin g annua l d-. v c-equivalent

limi t o f 5 0 mS v shoul dapply
. ; "•.!• ; limit i s considerabl y lowe

r tha n th e

, espondin g limit s recommende dfo r pre - • e::>;o n of non-stochasti c effect s after occu - ; vona l exposure . Th e intentio n i s t o ensure : :: : the longer

exposure perio dan dth e ;-. vcrical difficultie s i n controllin g th e tota l

. posur e fromal l source s wil

l no t resul t in ::- . vjhol d dose s for

non-stochasti c effect s i.-. u reached
. Th e weightin g procedur e commende din paragrap h 12 5 wil l generall y

. provid e th e necessar

y limitatio n als o for

non -

. :i-.!chasti c effects , bu t

th e specia l limitatio n i s ...neede d for th e ski n an dth e len s ofth e eye . 127 ) In th e calculatio n of

th e dos e equiva

len t incurre db

y member s ofth e publi c from V":;k e o f radionuclides , accoun t

mus t b e ;u!:c n o f difference s i

n organ siz e or

metaboli c characteristic s of

children
. Dat ao n suc h difference s ma

y b e foun din th e report

of th e •as k grou p o n Referenc e Ma n (ICRP Fublication23). (128) A s wit

h worker s (see paragrap h 102 ) a n increas e i

n th e averag e dos e t o member s o f 'di e publi c coul dresul t

fromany larg e increas e " i die number

of source s o

f exposure , eve

n dioug h each satisfactoril y me

t th e criteri ao

f '•'istification an doptimizatio n (se e para graph s 68-76 ) an dcause dn o exposure s abov e di e recommende dlimits
. Nationa l an d regiona l authoritie s shoul dtherefor e keep unde r surveillanc e th e separat e contribution s 1 ro mal l practice s t o th e averag e exposure o f ! 'i e whol e populatio n s o a s t o ensure tha t n o M "gle sourc e o r

practic e contribute s a n ''"justifie d amoun t

t o th e tota l exposure , an d '''a t n o individua

l receive s undu e exposure a s • l resul t o f membershi p o

f anumber o f critical groups . / : xposure of

populations C29 ) I n it s previou s recommendation s th e Commissio n suggeste dageneti c dos e limit , althoug h i t

expresse dreservation s abou t proposin g generall y applicabl e dos e limit s fo r populations
. I t

ha s becom e increasingl y clea r tha t th e previousl y suggeste dleve l i s no t likely t o b e reached , an di t

i s ver y improbabl e tha t responsibl e authoritie s woul dpermi t th e averag e dos e equivalen t

in apopulatio n t o reac h value s tha t

ar e mor e tha n smai l frac

tion s of th e former

geneti c dos e limit

o f 5 rem in 3 0 years . Therefore , continuanc e o f th e former geneti c dos e limi t

coul db e regarde d a s suggestin g th e acceptabilit y of ahigher populatio n exposure tha n i s either necessar y o r probable , an dahigher

ris k tha n i s justifie d by any presen t

o r easily envisage dfutur e development
. Furthermore , knowledg e gaine dove

r th e pas t tw o decade s indicate s tha t geneti c effects , whil e important , ar e unlikel y t o b e of

overridin g importance , an d woul dnee dt o b e relate dt o th e sumo f al l othe r effects
. (130) I n thes e recommendations , therefore , th e Commissio n doe s no t

propos e dos e limit s for populations
. Instea di t

wishe s t o empha

size tha t eac h man-mad e contributio n t o populatio n exposur e ha s t o b e justifie db y it s benefits , an dtha t

limit s for

individua l member s o

f th e publi c refe

r t o th e tota l dos e equivalent receive dfro mal l source s (excep t a s already noted)
. Th e limit

for irradiatio n of

a whol e populatio n i s thu s clearl y seen a s th e tota l reache dby asummatio n of minimu m necessar y contributions , an dno t

a s apermis

sibl e tota l apparentl y availabl e fo r apportion

ment
. Consideratio n o f th e principle s enunciate din paragraph s 117-125 , togethe r wit h th e Commission' s systemof dos e limita

tion , i s likely t o ensur e tha t th e averag e dos e equivalent t o th e populatio n wil

l no t excee d 0. 5 mS v pe

r year . (131 ) I n any cost-benefi t

assessment

o f a give n practic e (se e paragraph s 6 0 an d68-76 ) th e specificatio n of

th e collectiv e dos e equivalen t i s arelativel y straightforwar dpro cedure i f th e dos e equivalen t

i s limite dt o th e populatio n tha t

share s th e benefi t

o f th e source . I f th e exposur e wil

l involv e othe rP.3 3

26 RECOMMENDATION S O F TH E ICR P population s (o r

groups, , etc. } th e tota l collect

ive dos e equivalen t

should'b e kep t

belo w tha t which woul dhav e applie dha dth e cost
benefi t assessment

bee n confine dt o th e populatio n tha t

receive s th e benefit
. (132) Fo r th e purpose s envisage di n para grap h 12 8 i t

woul db e useful t o develo p long

ter mforecast s o f

th e tren dof

th e variou s con tribution s t o th e tota l collectiv e dos e equiva

lent delivere dfro mvariou s source s of exposure . Thi s woul dfacilitate discussion s of th e appropriat e nationa l an dinternationa l arrangement s i n regar dt o justificatio n for particular contribution s t o populatio n exposures . Contribution s tha t ar e no t primaril y controllabl e nationally , or o n an agree dregional basis , call for internationa l agreement o n level s of

exposure o r

collectiv e dos e equivalent s fromvariou s sources . I n orde r t o achiev e thes e objectives , suc h authoritie s ma

y findi t appropriat e t o appl y collectiv e dose-equivalen t

limit s for

variou s practice s o r

source s o f exposure . A ccidents and

emergencies (133 ) Unde r

condition s i n whic h accidental exposure s occur , question s aris e a s t o what remedial action s ma

y b e availabl e t o limit

th e subsequen t

dose
. In.suc h cases , th e hazar do r socia l cos t involve din an

y remedial measure mus t b e justifie db y th e reductio n of ris k tha t wil l result
. Becaus e o

f th e great variabilit y o f th e circumstance s in which remedia l actio n might b e considered , i

t i s no t possibl e fo

r th e Commissio n t o recommen d"interventio n levels " tha t

woul db e appropriat e fo r al l occasions
. However , wit

h certai n type s of acciden t tha t ar e t o som

e extent foreseeabl e i t ma y b e possibl e t o gauge , by a n analysi s of th e cost s of

th e acciden t

an dof remedial action , level s belo w whic h i

t woul dnot

b e appropriat e t o tak e action
. (134 ) Th e decisio n t o initiat e remedial actio n wil l hav e t o tak e accoun t

of th e partic

ula r circumstance s tha t

prevail
. I n general i

t wil l b e appropriat e t o institut e countenneas
ure s only when thei r

socia l cos t an dris k wil l b e les s than thos e resultin g fromfurther exposure . Nevertheless , a t th e operationa l leve l (a t areacto r establishment , for

example ) thos e responsibl e for

th e healt h an dsafet

y of workers , an dof

individual s outsid e th e estab

lishment , wil

l needt o hav e an emergenc y plan , includin g dos e level s at which variou s countenneasure s woul dhav e t o b e con sidered
. Th e settin g o

f suc h level s for

particu

la r circumstance s i s considere dt o b e th e responsibilit

y o f th e nationa l authorities
. (See als o sectio n G. ) (135 ) I t ha s been indicate din paragrap h 8 1 tha t th e Commission' s dose-equivalen t limit s ar e agree dvalues , establishe ds o a s t o make i t possibl e t o plan an ddesig n operation s involvin g foreseen bu t

acceptabl e radiatio n exposures . Thes e limit s ar e intende dt o apply only t o thos e condition s wher e th e sourc e o

f exposure i s unde r

control , an drelat e t o averag e worker s withou t

takin g any accouni o f ag e o r chil dexpectancy
. Th e Commission' s recommende dlimit s ar e se t a t aleve l whic h i s though t t o b e associate dwit

h alow degre e o

f risk ; thus , unles s alimit

wer e t o b e exceeded by aconsiderabl e amount , th e ris k woul dstill b e sufficiently lo

w a s no t t o warran t

suc h countenneasure s a s woul dthemselve s involv e significant risk s o r undu e cost
. It

i s therefore clea r tha t i t i s no t obligatory t o take remedia l actio n i f adose-equivalen t

limit ha s been o

r migh t b e exceede d(se e sectio n G)
. 

### F
. GENE R

(136 ) Th e recommend a th e report deal wit h th e g operationa l radiatio n p

r initia l conceptio n o f

a exposure t o ionizin g rad

i limitatio n of

such ex

p operations , t o th e pro c case s of acciden t or emer g (137 ) A s ha s bee

n state c i s convenient

t o defin e th r t o whic h thes e recommen c th e exposure of

individ t their work ; th e exposure of

indiv i medica l examinatio n o r othe r exposure s of

indi v Thes e point s ar e discussei G
.(138 ) Mor e detaile dre

< som e aspect s appear

i n committee s (se e Referen judgmen t i s calle dfor

i n t l thes e recommendations
. (139 ) Responsibilitie s f

c priat e radiatio n protec i employers , th e statutor y ities , th e manufacturer s product s givin g ris e t o r and , in some cases , th e ex

j management

of a n instit i al l th e necessar

y facilitie s f o f th e operation s und e particular , i t

shoul ddesig specia l dutie s for

protectio : o f radiatio n protectio n tea

t (140) Al l propose dins t operations , al l change s i r tion s an doperations , an da product s containin g radio ;CR P acciden t an do f remedial action , which i t woul dnot b e appropriat e >n . e decisio n t o initiat e remedial >av e t o tak e accoun t

of th e partic

stance s tha t

prevail
. I n genera

l i t opriat e t o institut e countermeas
le n their socia l cos t an dris k wil l b e thos e resultin g fro mfurther Nevertheless , a t

th e operationa l acto r establishment , fo

r example ) nsibl e for th e healt h an dsafet

y of do f individual s outsid e th e estab

- /il l nee dt o hav e a n emergenc y ling dos e level s a t

which variou s sure s woul dhav e t o b e con - : settin g of suc h level s for

particu

tance s i s considere dt o b e the
. t y o f th e nationa l authorities
. (See G. ) a s been indicate di n paragrap h 8 1 nmission' s dose-equivalent limit s alues , establishe ds o a s t o mak e i t > pla n an ddesig n operation s ?reseen bu t

acceptabl e radiatio n These limit s ar e intende dt o appl y i e condition s wher

e th e sourc e of
• unde r control , an drelat e t o rker s withou t

takin g any accoun t I d expectancy
. Th e Commission' s e dlimit s ar e se t

a t aleve l which i s 7 e associate dwit

h alow degre e of mles s alimi t

wer e t o b e exceeded :rabl e amount , th e ris k

woul dstil l itl y lo w a s no t t o warran t

suc h sure s a s woul dthemselve s involv e isk s or undu e cost
. I t

i s therefor e i s no t obligatory t o tak e remedial Jose-equivalent

limit ha s been o r .eede d (se e sectio n G)
. RECOMMENDATION S O F TH E ICR P


### GENERA L PRINCIPLE S O F OPERATIONA L RADIATIO N PROTECTIO N INTRODUCTIO N (136) Th e recommendation s of thi s part o f ;n e report dea l wit h th e genera

l principle s o

f operational radiatio n protection , fromth e initia l conceptio n of

aproposa l involvin g exposur e t o ionizin g radiations , throug h th e limitatio n o

f suc h exposure s in norma l operations , t o th e procedure s require din • . ase s o f acciden t o r emergency . (137 ) A s ha s been state din paragrap h 83 , i t i s convenient

t o defin e thre e type s o

f exposure t o which thes e recommendation s apply : th e exposure of

individual s i n th e cours e o f their work ; th e exposure of

individual s du e t o thei r medica l examinatio n o r

treatment ; an d other exposure s o

f individuals
. Thes e point s ar e discusse dfurther in sectio n G
. (138 ) Mor e detaile drecommendation s o n som e aspect s appear

in report s of

ICRP
. committee s (see References)
. Professional judgment i s calle dfor

i n th e applicatio n of

al l thes e recommendations
. (139 ) Responsibilitie s for

achievin g appro priat e radiatio n protectio n fal l o n th e employers , th e statutor y competen t author

ities , th e manufacturer s an dth e user s of product s givin g ris e t o radiatio n exposur e and , i n som e cases , th e expose dpersons . Th e management

of an institutio n mus t

provid e al l th e necessar

y facilitie s fo

r th e saf e conduc t o f th e operation s unde r

it s control
. I n particular , i

t shoul ddesignat e person s wit h specia l dutie s fo r protection , suc h a s member s o f radiatio n protectio n teams
. (140) Al l propose dinstallation s an dne w operations , al l change s i

n existin g installa

tion s an doperations , an dal l ne w o r modifie d Product s containin g radioactiv e material s o r 2 7

emittin g ionizin g radiation , s&nmffl d be examine dat

th e desig n stag e froamtffliepDintof vie w of restrictin g th e resultin g «naaE{pationa l an dgeneral exposure . Suc h exaimrnimion s can ofte n b e carrie dou t

by comgranissn

i wit h detaile dtechnical standard s prqpans i taking int o accoun t

th e recommendattiian s o f th e Commission
. (141 ) Befor

e commissioningannihstaiUlation , startin g a n operatio n o r

distributtongaipitoduct , i t shoul db e establishe dtha t tUneiinSfflillation, operatio n o r

produc t conform s \wtii

h th e approve dproposal s an dthat , th e ^jEpnropriat e radiatio n protectio n requiremenfl s Hmts been met
. I n th e cas e o

f installation s aud

i opera tions , ther e shoul db e contirtnitin g dtack s o n th e effectivenes s of

th e organnizifliiiima

l ar rangement s mad e t o achiev e praflseaBiom , an d o n th e availability an dapplicaflmn n of f appro priat e workin g instructions
. (142 ) Th e assessment

o f exposur e tof

f indi

vidual s or groups , carrie dou t

toy saalkiulatio

n o r measurement , i s an essential©mnpsimen t o f th e procedure s for

restrictin g esqpssjm

e an d for interventio n (se e paragrap h MS))
. Th e emphasi s a t

th e desig n an d earl y aparationa l stage s i s o n predictiv e assessraennlts;Bm>U „ wher e necessary , i s confirme dby maraianriimg(durin g subsequen t

operations
. Predidtin e 'assess

ment s ar e als o neede di n th e [plannin g o f interventio n procedure s but , i maatidition , monitorin g carrie dou t

durin g saaanmB

U opera tion s will ofte n provid e th e feasis fo r an y decision s t o intervene
. (143 ) Interventio n i s th e tera n lusad l when step s hav e t o b e take n t o depar t tfiwm mmorma l operatin g procedure s i n abnonmrilttitiua'tions , includin g accidents
. It s ai mi s tt ® mesttr'ic t th e exposure of

individual s an dt o iminhriiz e th e consequence s of

unavoidabl e tesqpsDsures
.P.3 5

2 8 RECOMMENDATION S O F TH E ICR P Interventio n usuall y involve s actio n t o regai n contro l oftheabnorma l situatio n an dcounter
measure s applie dt o individual s or thei r environment
. Th e broa dstructur e of th e procedure s fo r

interventio n shoul db e th e subjec t o f advance dplanning , takin g int o accoun t th e probability a s wel

l a s th e conse quence s o f

th e variou s situation s fo r which interventio n migh

t b e required
. Th e detail s ma y nee dt o b e settle di

n th e light

of th e prevailin g circumstances
.

PROTECTIO N STANDARD S (144 ) I t i s importan t

t o distinguis h between distinc t type s o f protectio n standards : basi c limit s (dose-equivalent

limit s an dsecondar

y limits) , derive dlimits , authorize dlimit s an d referenc e levels
. Limits (145 ) Th e dose-equivalent limits (see para graph s 10 3 an d104 , 11 9 an d126

) appl y t o th e dos e equivalen t

or , wher e appropriate , th e committe ddos e equivalent , in th e organ s o r tissue s of th e bod y of

a n individual or , in th e cas e o f exposure of

th e population , t o th e averag e of

on e of thes e quantitie s ove

r a grou p of individuals
. (146 ) Secondary limits ar e given for external irradiatio n an dfor

interna l irradiation
. I n th e cas e of externa l irradiatio n of

th e whol e body th e secondar

y limi t applie s t o th e maximum dos e equivalen t

in th e bod y at

depth s belo w 1 c m(see paragrap h 108)
. Th e secondar y limit s for interna l exposure ar e th e annua l limit s o f intak e by inhalatio n o r

ingestio n (se

e paragrap h 109)
. Thes e limit s o f intak e relate t o adul t Referenc e Man
. When , however , a critical grou p of

th e publi c differ s substanti

all y i n biological characteristic s from Referenc e Man , i t

ma y b e appropriat e t o tak e accoun t of suc h difference s (se e als o para grap h 127)
. (147 ) I n practica l radiatio n protection , i t i s often necessar

y t o provid e limit s associate d wit h quantitie s othe r

tha n dos e equivalent , committe ddos e equivalent , o r intake , an d relating , fo r

example , t o environmental conditions
. Whe n thes e limit s ar e relate dt o th e basi c limit s b y adefine dmode l o

f th e situatio n an dar e intende dt o reflec t th e basi c limits , they ar e calle dderived limits. Derive d limit s ma y b e se t fo r quantitie s suc h a s dose

equivalent rat e in aworkplace , contamina

tio n o f air , contaminatio n of

surface s an d contaminatio n o

f environmental materials
. Th e accurac y of

th e lin k between derive d limit s an dbasi c limit s depend s on th e realis m o f tri e model use din th e derivation
. (148 ) Limit s lai ddow n b y acompeten t authorit y o r

by th e managemen t

of an institu

tio n ar e calle dauthorized limits. Thes e should , in general , b e belo w derive dlimit s though , exceptionally , they ma y b e equal t o them
. Th e proces s o f

optimizatio n ma

y b e use din th e establishmen t

o f authorize dlimit s an dthe y appl y onl y i n limite dcircumstances
. I t i s importan t

tha t an y suc h limitation s shoul db e clearl y lai ddown
. Where an authorize dlimi t

exist s i t wil l alway s tak e precedenc e ove

r aderive dlimit
. Reference levels (149 ) Referenc e level s ma y b e establishe d for any o f th e quantitie s determine din th e cours e o f radiatio n protectio n programs , whether o r no t ther e ar e limit s for

thes e quantities
. A referenc e leve l i s no t alimi t an d i s use dt o determin e acours e o f actio n whe

n th e valu e o

f aquantit y exceed s or

i s predicte d t o exceedth e referenc e level
. Th e actio n t o b e initiate dma

y rang e fromsimply recordin g the information , throug h investigation s int o cause s an dconsequences , u p t o interventio n measures . I t

i s importan t

t o defin e th e genera

l scop e o f

iW s actio n whe

i cnc e leve l Hi e mos t

co m enc e leve l an e 'recordin g level s andiiaiKrventio n le

v (150 ) Mann

y measurer

m orin g program s sho w res t t o b e o f nmffisres t an dsu e discarde dwithou t

.bein g i helpfu l to drifin e aform a dos e eqpreaiflen

t .o r intak resul t i s ffiF sufficien t

i n recordin g ami

d keeping
. O

i be covecd%

- th e simpl e wer e a l Wm v fee defi n Theseumrainorde d result s > zer o fo r assessin g annua l intak e fo r tihe purpose s o tion
. TM $ abroac h resul : simplifkaanm

n o f th e recc results
. (151 ) Immestigation leve value s tsS-t&ose equivale n

(153 ) TB aapplicatio n optinrnannnn

i io tbe restr : and , inpamniQular , t o th e s c protectBKam

, acquire s acase situatkms.
. U

mpractice , a protecuMHm.iarrategies.i

s def i radiatfrnmesqposur

e an dth e goin g firaamn con

e strateg y t

c evaluated
. Bot h variatio r presse di mcomparabl e te

i stag e itlaat t pose s \th e great c als o psr,agii^ph s 72-76)
. (154)A$sfatted:i n paragr , assum e tifaatttihe detrimen t t tiona l t o flflneceoliective do s expose d ©nnu$p

, •bu t othe r c detrimen t mna y bs rnfluer highes t utaecaquivalen t

an c th e rafcmtnmniBship betwee n t relevan t intriit
. Tw o extre worth

- eHnMnaaering
. In th e fCR P

• probability a s wel

l a s th e conse th e variou s situation s for which 1 migh t b e required
. Th e detail s t o b e settle din th e light

o f th e ircumstances
.

ID S mit s by adefine dmode l o f th e dar e intende dt o reflec t

th e basi c ar e calle dderived

limits. Derive d j e se t for quantitie s suc h a s dose

rate i n aworkplace , contamina

contaminatio n o

f surface s an d ion of environmenta l materials
. c y of th e link betwee n derived" ' asi c limit s depend s o n th e realis m

. 1 use din th e derivation , nit s lai ddow n b

y acompeten t b y th e managemen t

o f a n institu

alled authorized

limits. Thes e general , b e belo w derive dlimit s eptionally , they ma

y b e equal t o proces s of optimizatio n ma

y b e •stablishment

of authorize dlimit s pl y only i n limite dcircumstances , tan t tha t any suc h limitation s clearly lai ddown
. Where an limi t exist s i t wil l alway s tak e ?ve r aderive dlimit
. ?vels erenc e level s ma

y b e establishe d th e quantitie s determine din th e radiatio n protectio n programs , no t ther e ar e limit s for

thes e \ referenc e leve

l i s no t alimit an d etermin e acours e of

actio n when aquantity exceed s o r

i s predicte d e referenc e level
. Th e actio n t o b e y rang e fromsimply recordin g th e i , throug h investigation s int o consequences , u

p t o interventio n : i s importan t

t o defin e th e genera

l RECOMMENDATION S O F TH E ICR P 29 scop e of thi s actio n when definin g th e refer

ence level
. Th e mos t

commo n form s o

f refer

enc e leve l are recordin g levels , investigatio n level s an dinterventio n levels
. (150) Man y measurement s mad e in monit

oring program s sho w result s tha t ar e to o low t o b e of interes t an dsuc h result s ar e often discarde dwithou t

bein g recorded
. I t

i s ofte n helpfu l t o defin e aforma

l recording level

fo r uos e equivalent

or intak e abov e which th e esul t i s of sufficient

interes t t o b e wort

h recordin g an dkeeping
. Othe r result s ca n the n b e covere db

y th e simpl e statemen t

tha t they ver e al l belo w th e define drecordin g level
. Thes e unrecorde dresult s shoul db e treate da s /c: o for assessin g annua l dos e equivalent o r iiv.ak e for th e purpose s of

radiatio n protec
-

- tion
. Thi s approac h result s i n aconsiderabl e simplificatio n o f

th e record s o f

monitorin g • results
. (151 ) Investigation levels ca n b e define da s vatue s of dos e equivalen t

o r intak e abov e which th e result s ar e considere dsufficientl y

importan t t o justif y furthe r investigations
. Fo r any define dtyp e of

measuremen t

i t i s possibl e t o establis h aderive dinvestigatio n leve l suc h tha t

ameasure dresul t

belo w th e derive dinvestigatio n leve

l will , wit h reason abl e certainty , correspon dt o avalu e of dos e equivalent or intak e belo w th e relevan t investigatio n leve

l (see paragraph s 178-181)
. (152) Althoug h th e detail s of interventio n wil l depen do n th e situatio n prevailin g a t th e time , experienc e ha s show n tha t i t i s ofte n useful t o hav e pre-establishe dintervention levels s o tha t

i f th e valu e of

aquantit y doe s no t exceedo r i s no t predicte dt o excee dth e inter

ventio n level , the n i t

i s highly improbabl e tha t interventio n will b e required
. Becaus e inter

ventio n i s liabl e t o interfer e wit h norma l operatio n or , i n some cases , t o disrup t th e norma l chai n of

responsibilities , i t

shoul dnu t b e undertake n lightly
.

OPERATIONA L OPTIMIZATIO N (153 ) Th e applicatio n o

f th e proces s of optimizatio n t o th e restrictio n of exposure and , i n particular , t o th e selectio n of level s of protection , require s acase-by-cas e revie w of situations
. In practice , aserie s of radiatio n protectio n strategie s i s defined
. Th e chang e in radiatio n exposure an dth e differential cos t o f goin g fro mon e strateg y t o th e next ar e the n evaluated
. Bot

h variation s nee dt o b e ex pressedin comparabl e terms , an di t i s thi s stag e tha t pose s th e greates t

difficultie s (se e als o paragraph s 72-76)
. (154) A s state di

n paragrap h 24 i t

i s usual t o assum e that th e detrimen t

t o healt h i s propor tiona l t o th e collectiv e dos e equivalen t in th e exposedgroup , bu t

othe r component s o f

th e detriment ma y b e influence dmore by th e highes t dos e equivalen t

and , i n particular , b

y 'h e relationshi p between thi s valu e an dth e relevan t limit
. Tw o extreme situation s ar e w ort h considering
. I

n th e first , th e detrimen t t o healt h in th e expose dgrou p i s th e pre dominan t componen t

of th e tota l detrimen t an dth e require dcompariso n i s th e differential chang e in th e cos t

of protectio n strategie s sin

d th e correspondin g differential chang e of th e collectiv e dos e equivalent
. Th e secon d extreme situatio n i s wher e th e detrimen t

t o healt h i s likely t o b e ver

y small , for

exampl e wher e th e number s of

individual s ar e extreme
l y limited
. Optimizatio n in thi s cas e involve s th e highes t

individual dos e equivalen t a s oppose dt o th e collectiv e dos e equivalen t an d i t i s necessar

y t o tak e accoun t

of exposur e contribution s fromprocedure s othe r tha n tha t unde r review
. (155 ) Some exposure s ar e du e t o mino r mishap s an d i t

i s the n necessar

y t o conside r no t onl y th e leve

l of exposur e bu t

als o it s probability , o r

more simply , t o loo k

a t th e long-ter maverag e of

th e exposur e of

indi

vidual s resultin g fro mboth continuou s an dP.3 7

3 0 RECOMMENDATION S O F TH E ICRP intermitten t

exposure . Thi s techniqu e allow s choice s t o b e mad e between th e resource s t o b e devote dt o th e reductio n o f routin e expos ure s an dthos e t o b e devote dt o th e avoidanc e o f mino r mishaps
. (156) It woul dals o b e convenien

t t o identif y th e possibl e additiona l benefi t tha t woul d result fromth e provisio n o f monitorin g resource s in additio n t o th e minimum necessar y t o demonstrat e complianc e wit h th e optimize dleve

l of exposure . However , i

t i s usually ver

y difficult t o quantif

y thi s kin do

f benefit , an dconsequentl y decision s ar e base d largely o n judgment
. (157 ) A s mos t

form s of interventio n involv e som e detriment , th e optimal-metho do f inter

ventio n depend s on abalanc e between th e detrimen t cause dby th e interventio n an dth e benefit expecte db

y th e reduction s o

f dos e achieve db

y th e intervention
. Suc h abalanc e necessarily depend s o n loca l circumstance s at th e time of th e situatio n callin g for

interven

tion , bu t preliminar

y plannin g shoul db e don e in advanc e o n acontingenc y basis
. (158 ) A considerabl e contributio n i s mad e t o radiatio n protectio n by th e us e of technical standard s an d specifications
. Th e case-by

cas e optimizatio n of

widely usedequipmen t

i s no t appropriat e becaus e i

t woul dnullif

y th e advantage s of

standardizatio n an dwoul d caus e ane t

socia l loss
. Optimizatio n should , however , pla

y apart i n th e settin g o

f suc h standard s an dspecification s an di n thei r subsequent

application
. (159 ) Whe n appropriat e dat afo

r tru e opti

mizatio n ar e lacking , amuc h crude r proces s ma y b e adopted
. Thi s proces s consist s o f applyin g afairly arbitrar y reductio n facto r t o alimit , o r

o f applyin g similarl y arbitrar y safet y factor s in plan t

design
. Th e resultin g exposure s ma

y the n b e either

highe r or lowe r tha n th e optimu mvalue
.



### APPLICATIO N T O TH E DIFFEREN T TYPE S

O F EXPOSUR E OCCUPATIONA L EXPOSUR E (160) Th e mai n responsibilit y fo r th e pro tectio n o f worker s rest s wit

h th e normal chai n o f management

i n a n institutio n possessin g any radiatio n sourc e tha t

cause s exposure o

f workers
. I t

i s necessar

y t o identif y technicall y competen t person s t o provide advic e o n al l relevant aspect s o f radiatio n protection , bot

h insid e an doutsid e th e institution , an dt o pro vide suc h technical service s a s are neede di n th e applicatio n of

th e appropriat e recom mendation s for

radiatio n protection
. Conditions of

work (161 ) Fo r th e purpose s of

thi s report

occu pationa l exposur e comprise s al l th e dos e equivalent s an dintake s incurre dby aworker ".durin g period s of

wor k (excludin g thos e du e t o medica l an dnatura l radiation)
. Th e scal e .and for mo f th e problem s o

f radiatio n protectio n of

worker s var

y ove r ver y wid e -ranges , an dther e ar e practica l advantage s in •introducin g asystemof classificatio n o

f condition s o f

work
. Condition s o

f wor k ca n •b e divide d int o tw o classes : Workin g Conditio n A : thi s describe s condition s where th e annua l exposure s migh t excee dthree-tenth s o

f th e dose

equivaleai limits ; WorkingConditio n B : thi s describe s condi

tion s where i

t i s mos t unlikel y tha t

th e annua l exposure s will exceedthree-tenth s of thedose-equivalen t

limits
. Th e valu e o f three-te n fo r occupationa i expo s leve l usedin th e organi ; is no t alimit
. Where t nccted wit h th e work , a ; premise s no t

containin : givin g ris e t o th e e

x conditio n shoul db e su

e cabl e t o member s o

f the (162) Th e mai n aim Workin g Conditio n / worker s wh o migh

t ot h th e dose-equivalen t

l i individua l monitorin g s ca n b e restricte di

f n e Conditio n B , individ

u necessary , althoug h i

t carrie dou t

a s ametho d condition s ar e satisfact

c (163 ) Th e practica l syste mof classificatio n > i s greatl y simplifie db

y correspondin g system workplaces
. Th e mini

m define controlle dare : operatio n woul dgiv e ri : tion A an dt o which a demarcatio n o f

contro l o n th e operationa l situ e be convenien t

t o us e boundaries
. Th e contro l cas e b e larg e enoug h t o tha t th e annua l dose-e c outsid e th e controlle da tenth s o f th e limits
. (164 ) I t i s sometime s c further clas s of work ] "supervise darea" , a

i chosen s o a s t o mak e i t

i annua l dos e equivalent vise dare awil l excee dor, (165)Thereisnosimp I the classificatio n o f

ar e tio n of workin g con e classificatio n of

area s ta tim e spen t b y worker s i ; cours e o f th e yea r an d b
. rarel y unifor

mthrough o 

# 1 IHv- J

R P h e situatio n callin g for

interven

iminar y plannin g shoul db e don e 1 acontingenc y basis , msiderabl e contributio n i s mad e protectio n by th e us e of

technical i d specifications
. Th e case-by

atio n o f widel y usedequipmen t

i s iat e becaus e i t

woul dnullif

y th e o f standardizatio n an dwoul d ocia l loss
. Optimizatio n should , i y apart in th e settin g o

f suc h a d specification s an din thei r pplication
. n appropriat e dat afor

tru e opti

lacking , amuc h crude r

proces s pted
. Thi s proces s consist s o f irly arbitrar y reductio n facto r t o 3 f applyin g similarl y arbitrary
• s in plan t design
. Th e resultin g i y the n b e eithe r

higher o r lowe r nu mvalue
.

:REN T 

## TYPE S
R E
i s o f wor k (excludin g thos e du e i d natura l radiation)
. Th e scal e > f th e problem s o

f radiatio n f worker s var

y ove r ver y wid e her e ar e practica l advantage s i n asystemof

classificatio n o

f
" work
. Condition s of

wor k ca n o tw o classes : Conditio n A : thi s describe s wher e th e annua l exposure s -'c d three-tenth s o

f th e dose

limits ; onditio n B : thi s describe s condi

e i t i s mos t unlikely that

th e osure s wil l excee dthree-tenth s equivalen t limits
. RECOMMENDATION S O F TH E ICR P 3 1 Th e valu e of

three-tenth s of

th e basi c limit s fo r occupationa l exposure i s thu s areferenc e leve l use din th e organizatio n of protection
. It i s no t alimit
. Where th e exposure i s uncon nectedwit h th e work , an dwher

e th e wor k i s in premise s no t

containin g th e radiatio n source s givin g ris e t o th e exposure , th e workin g conditio n shoul db e suc h tha t th e limit s appli

abl e t o member s of

th e publi c ar e observed
. (162 ) Th e mai n ai mof

th e definitio n o

f workin g Conditio n A i s t o ensure tha t vorker s wh o migh

t otherwis e reac h o r

exceed th e dose-equivalen t

limit s ar e subjec t

t o individua l monitorin g s o tha t

thei r exposure s ca n b e restricte dif

necessary . In Workin g Conditio n B , individual monitorin g i s no t necessary , althoug h i t

ma y sometime s b e carrie dou t

a s ametho do f

confirmatio n tha t condition s ar e satisfactory
. (163 ) Th e practica l applicatio n of thi s • .ste mo f classificatio n o

f workin g condition s : > greatl y simplifie db

y th e introductio n of

a correspondin g syste

mo f classificatio n of workplaces
. Th e minimu mrequiremen t i s t o defin e controlle darea s wher e continue d operatio n woul dgive ris e t o Workin g Condi

tion A an dt o whic h acces s i s limited
. Th e demarcatio n o

f controlle darea s wil

l depen d o n th e operationa l situatio n an di t wil l often b e convenient

t o us e existin g structura l boundaries
. Th e controlle dare ashoul din any cas e b e larg e enoug h t o make i t mos t unlikel y tha t th e annua l dose-equivalent s t o worker s outside th e controlle dare awil l exceedthree

tenth s o f th e limits
. (164 ) I t i s sometime s convenien t

t o specif y a furthe r clas s of workplace
. I

t i s calle da "supervise darea" , an dha s aboundar y chose n s o a s t o make i

t mos t unlikel y tha t

th e annua l dos e equivalent s outsid e th e super vise dare awil l exceedone-tent

h o f th e limits
. (165 ) Ther e i s n o simpl e parallelis mbetween th e classificatio n of

area s an dth e classifica

tio n o f workin g conditions , becaus e th e classificatio n o f

area s take s n o accoun t

o f th e tim e spent b y worker s i

n th e are adurin g th e eours e o f th e yea r an dbecaus e condition s ar e r arcl y unifor

mthroughou t

a n area . (166 ) I n orde r t o simplif y th e arrangement s for medical supervisio n an dfor individual monitoring , i t

i s usua l t o classif

y individual workers
. I n principle , thi s can b e don e i n term s o f th e clas s of

workin g condition s i

n which they operate , bu t

in practic e i t

almos t alway s ha s t o b e don e i

n term s o f th e area s wher e the y work , th e typ e of

wor k don e and , i f thi s can b e forecas t

wit h sufficient

reli

ability , th e time t o b e spen t in th e area . Provisions.for

restricting exposure (167 ) A s fa

r a s i s reasonabl y practicable , th e arrangement s for

restrictin g occupationa l exposure shoul db e thos e applie dt o th e sourc e o f radiatio n an dt o feature s o f th e workplace
. Th e us e o f

persona l protectiv e equipmen t shoul di n general b e supplementary t o thes e more fundamenta l provisions
. Th e emphasi s shoul dthu s b e o n intrinsi c safet y in th e work

plac e an donl y secondaril y o n protectio n tha t depend s o n th e worker' s ow n actions
. (168 ) Acces s t o controlle darea s shoul db e restricted , at

leas t by th e us e o

f warnin g signs
. Insid e controlle darea s i t

ma y sometime s b e necessar y t o defin e region s wher

e complianc e wit h th e relevan t

limit s can b e achieve donly b y limitin g th e time spen t

in th e regio n o r

b y usin g specia

l protectiv e equipment
. Th e acces s o f worker s t o controlle darea s shoul d b e limite dt o thos e wh o ar e assigne dt o th e are aan dt o other s wh o hav e been authorize d t o hav e access . Th e acces s of worker s t o supervise darea s shoul db e th e subjec t o f loca l operatin g instructions
. Visitors , either worker s o r

member s of

th e public , shoul db e admitte dt o workplace s onl y wit h th e approva l of

an appropriat e leve

l of th e managemen t

responsibl e for

th e workplace
. (169 ) Externa l exposur e ma y b e restricte d b y th e us e of

shielding , distanc e an dlimita

tio n o f time o f exposure . Shieldin g produce s intrinsicall y saf

e condition s i

n th e workplace
. Distanc e an dlimitatio n o f tim e of exposure require th e carefu l trainin g an d supervisio n o f workers
. Complet e protectio n i s afforde db y th e us e o f "closed " installation s providin gP.3 9

3 2 RECOMMENDATION S O F TH E ICR P virtuall y complete shielding.fo r th e radiatio n sourc e an deffectively preventin g access . However , th e failur e o

f suc h equipmen t

a s interloc k system s ma

y caus e excessive exposure . Operatin g procedure s shoul dthere

for e includ e routin e check s o

f suc h systems
. (170) Contaminatio n b y radioactiv e material s ma

y b e restricte db y containmen t an dcleanliness
. Containment , which pro vide s intrinsi c safety , consist s of aserie s o

f barriers , thei r

numbe r bein g afunctio n of

th e potentia l hazard s involved
. Tota l contain

ment i s no t alway s justifie dan dpartia l con tainmen t ma y b e sufficient

provide dthat

i t i s supplemente dby ahigh standar dof cleanli

ness . Ventilatio n play s asignificant par t i n both containmen t

an dcleanliness
. When contaminatio n of

th e workplac e canno t

b e excluded , persona l protectiv e equipmen t ha s apar t t o play i n th e protectio n o f workers
. (171 ) Althoug h th e Commissio n give s recommendation s relatin g t o planne dspecia l exposure s t o interna l contaminatio n (se e paragrap h 113 ) th e us e o f protectiv e equip

ment shoul dmak e such exposure s unneces sary . (172 ) Al l worker s wh o ma y hav e acces s t o supervise do r

controlle darea s shoul db e properl y traine dan dgive

n appropriat e infor

matio n abou t

th e hazards-o f

thei r wor k an d abou t th e precaution s the y shoul dtak e t o protec t themselves
. The y shoul db e mad e aware of th e importanc e o

f complyin g wit

h th e workin g instructions
. Monitoring of

exposure (173 ) Worker s designate da s operatin g i n Workin g Conditio n A shoul db e th e subjec t of individua l assessment

o f dos e equivalent , committe ddos e equivalen t o r intake , a s th e cas e ma y be
. Thi s consist s of

individual monitorin g for

external irradiatio n an dfor interna l contaminatio n a s appropriate
. I n som e case s i t wil l b e necessar

y t o us e indirec t methods
. A n individua l assessment of expos ur e i s no t require dfor

worker s designate da s workin g i n Workin g Conditio n B
. I t i s suffi

cient

t o asses s th e condition s i n th e workin g environment , followin g th e principle s an d recommendation s se

t ou t in ICRPPublication 12. (174 ) Monitorin g program s shoul db e designe dt o meet

clearly define dobjectives : routin e monitoring , associate dwit h continu

in g operations , monitorin g of a n operation , applie dt o aparticular

operation , an dspecia

l monitorin g i n a n actua l o r suspecte dab

normal situation
. I n additio n t o th e primar y aims , mos t

monitorin g program s hav e supplementar

y functions
. Th e program s shoul db e reviewedboth periodicall y i n th e ligh t o f experience , an din th e even t o f any majo r modificatio n o f

th e installatio n o r

th e operations , t o ensure tha t they continu e t o mee t their objectives
. The use of protection standards to interpret monitoring results. (175 ) Us e ca n b e mad e o

f derive dlimit s o r

authorize dlimit s i

n th e applicatio n of

individual monitorin g pro grams . Suc h limit s ar e essential i n th e monitor

ing of operation s where , in general , only part ofth e dose-equivalent

limi t or secondar y limit ca n b e committe dt o th e operation
. (176 ) Onl y i n afe

w circumstance s ca

n th e result s of program s of

monitorin g of

th e workplac e b e use dt o estimat e th e dos e equivalent s o r

intake s o f

individual workers
. Th e us e o f

derive do r

authorize dlimit s i s essentia l i n th e interpretatio n o f environ

mental monitorin g programs . (177 ) A substantia l par t

of al l monitorin g program s i s confirmatory i n natur e and , give n satisfactor y results , n o furthe r

actio n need s t o b e taken
. I n thes e circumstance s ther e i s a possibilit y tha t th e occasional significant resul t wil l b e overlooked , unles s us e i s mad e o f investigatio n level s an dderive dinvestiga

tion levels
. Th e initial actio n t o b e take n when aresul t exceed s an investigatio n leve l shoul d b e determine di n advance
. (178 ) I t i s possibl e t o giv e general guidanc e o n investigatio n level s for

individual monitor

ing tha t applie s i n alarg e numbe r o f situa

tions
. Sinc e ther e i s n o Commissio n recom mendatio n o n i n Workin g Conditio ; unlikely tha t

th e e ? tenth s of th e app i secondar y o r deriv e priat e t o us e rhi s settin g investigati c monitoring
. Howe \ t o b e useful , ha s to 1 measurement , no t equivalen t o r intak appropriat e t o bas e th e fractio n of

thre e pondin g t o th e fra

c individual monito r Correspondin g dei ca n the n b e deduce d measured
. (179 ) Somewha

t appl y i n th e settin g program s of

spec i monitorin g i s asso c thoug h no t

neces ; principle , th e choi e depend s o n th e ex

p occasion s o n whic

h durin g th e year . I n Commissio n reco m tio n leve l shoul dco : o f th e annua l do s leve l bear s th asain

t equivalen t li.ni t a s leve l for routin e n v tha t event s requiri monitorin g ma

y o c individual abou t

si x (180) Investigati c monitorin g wil

l de ] for mo f th e monit

c typ e of investigati c commo n for

mo f i monitorin g of

w o expecte dconsisten c conditions
. (181 ) Althoug h i

t abl e for initiatin g i : situations , i t

ma y dos e equivalent s a Th e Commissio n r

eion s i n the workin g th e principle s an d n ICRPPublication >gram s shoul dbe define dobjectives : .iate d wit h continu

- ;g o f a n operation , eration , an dspecia

l i o r suspecte d ab

tio n to the primar

y : program s have s . Th e program s periodically i

n th e i n the even

t o f an y c installatio n o r

th e i t the y continu e to
•mdards to interpret Us e ca n b e mad e o

f ize d limit s i n th e i monitorin g pro ntialinthemonitor

n general , onl

y par t i t o r secondar y limi t >cration
. cumstance s ca

n th e monitorin g o

f th e estimate th e dos e individua l workers , uthorize dlimit s i s tatio n of environ

rris
. t o f ail monitorin g i n nature and , give

n the r actio n need s t o nstance s there i s a asiona l significant unles s us e i s made 1 derive dinvestiga

m t o betake n whe

n gatio n leve

l shoul d

• e genera l guidanc e ndividua l monitor-
. c numbe r o f situa

ommission rccomRECOMMENDATION S O F TH E ICR P 3 3 mendatio n o n individual monitorin g i n Workin g Conditio n B (i.e
. wher e i t i s mos t unlikely tha t

th e exposure wil

l exceedthree

tenth s of th e appropriat e dos e equivalent , secondar y o r derive dlimits ) i

t i s ofte n appro priat e t o us e thi s figure of three-tenth s in settin g investigatio n level s for individual monitoring
. However , an investigatio n level , t o b e useful , ha s t o b e set

in relatio n t o asingl e measurement , no t

th e accumulate ddos e equivalent or intak e in ayear , an di t

i s mos t appropriat e t o bas e th e investigatio n leve l o n th e fractio n o

f three-tenth s of

th e limi t corres pondin g t o th e fractio n of

ayea r t o whic h th e individual monitorin g measuremen t refers
. Correspondin g derive dinvestigatio n level s ca n the n b e deduce dfor

th e quantitie s directl y

. measured
. .(179 ) Somewha

t differen t consideration s appl y i n th e settin g o f

investigatio n level s for program s of

specia l monitoring
. Her e th e monitorin g i s associate dwit h asingl e event , thoug h no t

necessarily auniqu e one . I n principle , th e choic e o f

a n investigatio n leve

l depend s o n th e expectatio n o f th e numbe r

of occasion s o n whic h simila r event s will occur durin g th e year . I n ICRPPublication 10, th e Commissio n recommend s tha t th e investiga

tio n leve l shoul dcorrespon dt o one-twentiet h o f th e annua l dose-equivalen t limits
. Thi s leve l bear s th e same relationshi p t o th e dose

equivalent limi t a s doe s th e correspondin g leve l fo r routin e monitoring , i

f i t i s assume d tha t event s requirin g aprogramo f specia l monitorin g ma

y occur i n relatio n t o asingl e individua l abou t si x time s in ayear . (180) Investigatio n level s fo r othe r type s o f monitorin g will depen do n th e objective s an d for mof th e monitorin g programan do n th e typ e of investigatio n t o b e carrie dout
. On e commo n for

mof investigatio n leve

l for th e monitorin g o f

workplace s i s base do n th e expecte dconsistenc y of

result s durin g norma l conditions
. (181 ) Althoug h investigatio n level s ar e suit

abl e fo r initiatin g investigation s int o specifi c situations , i t

ma y b e convenient

t o recor d dos e equivalent s a

t somewha

t lowe r levels
. Th e Commissio n recommend s tha t recordin g level s shoul db e base do n an annua l dos e

equivalen t o r intak e o f

one-tenth of

th e annua l dose-equivalen t

limi t o r intak e limit
. (182) Fo r th e specia

l cas e of monitorin g o

f skin , tw o situation s occur

in routin e practice
. Fo r external radiatio n ados e equivalen t i s measure db y on e o r

tw o dosemeter s an dth e result s ar e treate da s representativ e of th e whole , o r of substantia l areas , of

th e skin
. N o proble mo f

averagin g the n arise s an dth e result s ar e relate ddirectl y t o th e relevan t dose-equivalen t

iimit
. I n th e secon dsituation , th e irradiatio n result s fromsurfac e contamin

atio n o n th e skin
. Thi s i s neve r uniforman d occur s preferentiall y on certai n part s o f th e body , notabl y th e hands
. However , i t doe s no t persis t ove r man y weeks an ddoe s no t alway s occur

agai n a t exactl y th e sam e places
. Fo r routin e purposes , i t

i s adequat e t o regar d th e contaminatio n a s bein g average dove r area s o f abou t 10 0 cm 2

. Routin e monitorin g fo r ski n contaminatio n shoul dtherefor e b e interprete do n thi s basi s an dth e limi t applie d t o th e averag e dos e equivalen t ove r 10 0 cm 2

. (183 ) I n accident s o r

suspecte daccidents , mor e detaile dinformatio n shoul d b e sough t o n th e distributio n of

absorbe ddose , dos e equivalen t o r contamination
. A n estimat e shoul db e mad e of

th e averag e dos e equivalen t ove r 1 cm 2 in th e regio n of

th e highes t

dos e equivalent
. Thi s dos e equivalen t shoul dthe n b e compare dwit

h th e dose-equivalen t

limit
. I f th e dos e distributio n i s extremel y non uniform , a s i s tha t

fro mver y smal l particle s i

n contac t wit h th e skin , th e local distributio n o f absorbe ddos e shoul db e assesse dan duse dt o predic t possibl e local ski n reactions
. I t i s inappropriate , however , t o relat e suc h local

ize dabsorbe ddose s t o th e absorbe d dose s correspondin g t o th e dose-equivalen t limit
. Medical surveillance (184 ) Th e medica

l surveillanc e o f

worker s expose dt o radiatio n i s base do n th e general principle s of

occupationa l medicine
. It ha s th e followin g aims : t o asses s th e healt

h of th e worker ; t o hel p in ensurin g initia l an d continuin gP.4 1

3 4 RECOMMENDATION S O F TH E ICR P compatibility betwee n th e healt h o f th e worker s an

d the condition s of

thei r work ; t o provid e abas e lin e of

informatio n usefu

l in th e cas e o f

accidental exposure or

occu pationa l disease
. Deleteriou s effect s canno t b e unequivocall y associate dwit

h exposure s withi n th e dose

equivalent limits , an dmedica

l surveillanc e ha s n o par t

t o play in confirmin g th e effect

ivenes s of aradiatio n protectio n program . Medica l surveillanc e ma

y includ e bot

h pre operationa l an droutin e examinations , th e latte r bein g determine dmainl y by th e worker' s general stat e o f

healt h an db y th e condition s of

work
. (185 ) Worker s designate da s operatin g i n Workin g Conditio n A shoul db e give n apre operationa l medica

l examinatio n before startin g thi s kin dof

work , thoug h no t

neces sarily before employment
. On e objectiv e o f thi s examinatio n i s th e recognitio n of condi

tion s o r characteristic s tha t

limi t th e typ e o f exposure t o whic h th e individual shoul db e subjected
. Fo r

thes e purposes , th e physicia n need s informatio n abou t

th e condition s o f work , includin g detail s of

th e jo b description
. (186 ) Followin g a preoperationa l examina

tion , consideratio n shoul db e given t o th e nee dfor a continuin g surveillanc e o f th e healt h o f workers
. I f

thi s i s needed , th e physicia n shoul dhav e acces s t o informatio n hel db y th e employin g organizatio n abou t th e workin g condition s (e.g
. jo b descriptio n an d workin g environment ) an dabou t th e stat e o

f healt h of worker s (e.g
. absence s du e t o sickness)
. I t

i s principall y o n th e basi s o f thi s informatio n tha t

th e frequenc y of

any routin e examination s shoul db e decided
. (187 ) Th e Commissio n consider s that , wit h th e present

dose-equivalen t

limits , n o specia

l administrativ e arrangemen t i s appropriat e for worker s a s fa

r a s radiatio n risk s ar e con cerned
. I n particular , n o specia l arrangemen t i s require dwit

h respec t t o workin g hour s an d lengt h o f vacation
. Intervention in abnormal situations (188 ) Arrangement s shoul db e mad e fo r dealin g wit

h abnorma l situations , no t onl y wit h respec t t o thei r detectio n an dth e assess men t of dos e o r intake , bu t

als o wit h respec t t o th e for mof interventio n tha t

ma y hav e t o b e applied
. Th e interventio n level s an dth e appropriat e action s fo r

limitin g exposure shoul db e th e subjec t

o f operatin g instruc

tions.

- Provisio n shoul db e mad e for specia l medica l surveillanc e and , if

necessary , treat
ment followin g exposur e substantiall y in exces s ofth e dose-equivalen t limits
. (189 ) Th e emergenc y plan s (which should , a s fa r a s practicable , b e draw n u p in advance ) shoul dhav e thre e clearl y distinguishe d objectives
. Th e firs t

i s t o restric t

exposure s a s fa r a s i s reasonabl y achievabl e and , in partic

ular , t o attemp t

t o avoi dexposure s abov e th e dose-equivalen t

limits
. Th e secon di s t o brin g th e situatio n bac k

unde r control , an dth e thir d i s t o obtai n informatio n for assessin g th e cause s an dconsequence s ofth e event
. (190 ) Although , b y thei r

nature , accidental exposure s ar e no t

subjec t t o control , thei r magnitud e ca

n t o som e exten t

b e limite db

y intervention , especiall y i f

attentio n ha s been pai dt o thi s possibilit

y durin g th e desig n o

f installation s an dequipmen tan d th e prepara

tion o f operating instructions . (191 ) Durin

g th e immediat

e cours e of

a serious incident , urgen

tactio n t o save life , t o preven t injuries , o r t o preven

ta substantia l increas e i n th e scal e o f

th e incident , ma

y requir e tha t

som e worker s b e expose din exces s o f th e limit s applicabl e t o aplanne d specia l exposure . Suc h worker s shoul db e volunteers , an di t

i s desirable tha

tgroup s o f worker s likely t o provide suc h volunteer s should , a s par t

o f thei r norma l training , receiv e informatio n abou t risks involve di

n exposure s abov e th e limits
. I twill no t normall y b e possibl e t o contro l suc h exposure s i n detail, bu t substantia l effort s shoul d b e mad e t o pro vid e a n upper limi t t o th e likel y exposures . (192 ) Onc e th e initia l event ha s bee n brough t unde r control , ther e remain s th e proble mof remedia l work
. I t will usuall y b e appropriat e t o carr y thi s ou t whil e maintaining complianc e wit h th e Commission' s recommende d limit s but, exceptionally , i

which th e us e o

f th < excessive expens e o

r o f peopl e an dri

m the n b e give

n to th e a izing aplanne dspec number o f individt essentia l operation s bedonei n compliant (193 ) A s aresul t individual worker s i or contaminated
. In ure , th e immediat e a t o collec t inform a stance s o f th e accide tests , wit h avie w t o th e individual s wh o substantiall y abov e of contaminatio n o

f intak e b y inhalatio : activ e substances , actio n i s indicated
. actio n i s largel y dete which i t ca n b e carri e t o contro l contami i lowe dt o interfere w

i quen t treatmen t

o f medica l attentio n fo

i wil l often hav e t o ground s rathe r

than

(195 ) Th e ter

mm th e exposure o

f indi ' examinatio n or

trea t Mos t medica l expo s us e o f radiatio n for purposes , bu t

some cas e of cardia c pa

< activ e powe

r sourc e useful part

an dt adventitious
. (196 ) Th e object : cedure s are :RECOMMENDATION S O F TH E ICR P ituations , no t

onl y tio n an dth e assess u t als o wit h respec t n tha t ma y hav e t o tio n level s an dth e .limitin g exposur e operatin g instruc

e mad e fo r

specia l if necessary , treat
e substantiall y i n :n t limits
. an s '(whic h should , aw n u p i n advance ) arl y distinguishe d estric i exposure s a s abl e and , i n partic

xposure s abov e th e e secon d i s t o brin g mtroii , an d th e thir d fo r assessin g th e ftheesent
. r nature , accidenta l t t o control , thei r •cten t fee limite db y attentio n ha s bee n ir'in g tthe desig n o f n t an dth e prepara - >ns . ediat e cours e o f

a tio n t o sav e life , t o even t asubstantia l th e incident , ma y ..T S b e expose di n cabl e t o aplanne d /orker s shoul db e ibl e tha t group s o f e suc h volunteer s norma l training , t risk s involve di n I twil l no t normall y exposure s i n detail , tl d b e mad e t o pro - :el y exposures , itha s bee n brough t in s th e proble mo f ill y b e appropriat e lainingcomplianc e commende dlimit s but , exceptionally , ther e ma y b e situation s i n whic h th e us e o f

th e limit s woul dinvolv e a n excessiv e expens e o r

a n excessiv e involvemen t o f peopl e an dtime
. Consideratio n shoul d the n b e give n t o th e appropriatenes s o f author

izin g aplanne dspecia l exposur e fo r alimite d numbe r o f individual s t o carr y ou t variou s essentia l operations , leavin g th e remainde r t o b e don e i n complianc e wit h th e limits
. (193 ) A s aresul t

o f abnorma l situations , individua l worker s ma y b e seriousl y expose d o r contaminated
. I n respec t o f externa l expos ure , th e immediat e actio n neede di s essentiall y t o collec t

informatio n abou t

th e circum

stance s o f

th e acciden t

an dt o initiat e medica l tests , wit h avie w t o subsequen t diagnosis , o n th e individual s wh o ma y hav e bee n expose d substantiall y abov e th e limits
. I n som e case s o f contaminatio n o f

ski n o r wounds , o r

o f th e intak e b y inhalatio n o r ingestio n o f

radio

activ e substances , immediat e therapeuti c actio n i s indicated
. Th e effectivenes s o f th e actio n i s largel y determine d b y th e spee dwit h whic h i t ca n b e carrie dout
. However , th e nee d t o contro l contaminatio n shoul dno t b e al

lowe dt o interfer e wit h th e firs t ai dan dsubse

quen t treatmen t

o f individual s wh o requir e medica l attentio n fo r

othe r reasons . Decision s wil l ofte n hav e t o b e mad e o n qualitativ e ground s rathe r

tha n o n th e basi s o f

carefull y mad e an dinterprete dmonitorin g measure ments
. I t

i s particularl y importan t i n thi s respec t tha t ther e shoul db e aclos e workin g relationshi p betwee n th e managemen t o f th e institution , th e individual s wit h specia l responsibilitie s fo r

radiatio n protection , an d th e medica l staff , whethe r thes e b e associate d wit h th e institutio n o r

th e loca l hospital
. I t

i s essentia l tha t

suc h workin g relationship s b e develope di n advance
. (194 ) Th e principa l administrativ e arrange ment s t o b e mad e afte r

a n abnorma l even t

ar e thos e concerne dwit h initiatin g a n investiga

tio n int o th e cause s an dconsequence s o f th e even t an dwit h reachin g decision s abou t th e nee dfo r an y restrictio n o n th e futur e employ

men t o f thos e involve d i n th e event
. I f th e dos e o r th e intak e o f

radioactiv e materia l exceed s twic e th e annua l limit , th e cas e shoul db e subjec t t o appropriat e medica l review
. Th e worke r ma y stil l b e allowe dt o continu e routin e wor k

i f ther e i s n o objectio n fro mth e medica l standpoint , du e accoun t havin g bee n take n o f previou s exposure , health , ag e an d specia l skills , a s wel l a s socia l an deconomi c responsibilities
. However , th e even t ma y hav e demonstrate dcharacteristic s i n individual s indicatin g unsuitabilit y fo r furthe r employ

men t i n simila r

work
.

MEDICA L EXPOSUR E (195 ) Th e ter mmedica l exposur e refer s t o th e exposur e o f

individual s subjec t

t o medica l examinatio n o r

treatmen t

involvin g radiation
. Mos t medica l exposure.i s concerne dwit h th e us e o f radiatio n fo r

diagnosti c o r

therapeuti c purposes , bu t

sometimes , fo r

exampl e i n th e cas e o f cardia c pacemaker s usin g aradio

activ e powe r

source , th e radiation s pla y n o usefu l par t

an dth e exposur e i s merel y adventitious
. (196 ) Th e objective s o f th e medica l pro cedure s are : examination s o r treatment s directl y associ

ate dwit h illness ; systemati c examination s undertake n fo r mas s screenin g purpose s o r fo r periodi c healt h checks ; examination s formin g par t o f th e medica l surveillanc e o f

worker s o r

carrie dou t

fo r medico-lega l o r

insuranc e purposes ; examination s o r

treatmen t

formin g par t

o f amedica l researc h program .P.4 3

3 6 RECOMMENDATION S O F TH E ICR P Examinations or

treatments directly associassociated

with illness (197 ) Th e decisio n a s t o whether a n exam inatio n involvin g acertai n radiatio n dos e t o a patien t i s justifie di s sometime s th e responsi

bilit y of th e referrin g physician , an dsome times of th e practitione r

wh o carrie s ou t

th e procedure.
. I n either

case , however , i

t i s imperativ e tha t

th e decisio n b e base dupo n a correc t assessment

of th e indication s for

th e examination , th e expecte dyiel dfromth e examinatio n an dth e wa

y i n which th e result s ar e likel y t o influenc e th e diagnosi s an dsubse

quent medica l car e ofth e patient
. It

i s equally importan t tha t thi s assessment

b e mad e agains t abackgroun dof

adequat e knowledg e o f th e physica

l propertie s an dth e biologica l effect s o f ionizin g radiation
. (198 ) I n therapeuti c exposures , th e absorbe d dose s t o organ s ar e i

n genera l ver y muc h highe r an dboth th e danger s o

f th e exposure an dth e benefit s o f

th e treatmen t

ca n b e asses se dmore quantitatively
. Th e decisio n ca n the n b e base do n abalanc e betwee n thes e aspects
. I t i s als o necessar

y t o consider

altern

ativ e therapeuti c procedure s an dt o compare their effectivenes s an dthei r

danger s wit

h thos e associate dwit

h radiological treatment
. (199 ) Whil e i t

i s importan t

tha t th e decisio n t o procee dwit

h examination s o r

treatmen t involvin g exposure t o radiation s shoul dtak e int o accoun t

th e danger s o f

such exposures , i

t i s equall y importan t

tha t thes e danger s shoul d no t b e overestimated , sinc e thi s might lea dt o th e rejectio n o f

justifie dexamination s o r treatments
. Systematic examinations (200) Periodi c healt

h check s undertake n withou t referenc e t o curren t

illnes s ma

y involv e som e radiological examinations
. Thei r justificatio n depend s on th e probability o f obtainin g useful informatio n an dth e importanc e of

thi s informatio n for

th e indi

vidual' s health
. (201 ) Fo r th e systemati c examination s use d i n mas s screening , th e justificatio n shoul db e base do n abalanc e betwee n th e advantage s implie dfor

th e individual s examine dan dfor th e populatio n a s awhole , togethe r wit h th e costs , includin g detriment , o f th e screening
. I n general , th e advantage s wil l depen do n th e yieldof th e screenin g procedure , th e possi

bilit y o f effectiv e treatmen t

of th e case s detecte dand , for

certai n diseases , th e advan

tage s t o th e communit

y of th e contro l o f

th e disease
. Th e benefit s of

screenin g ar e no t alway s th e same fo r

differen t group s makin g u p th e populatio n an dscreenin g wil l ofte n b e justifie donl y i

f i t i s limite dt o certai n specifie d groups . Th e programshoul db e subjec t t o frequent examinatio n t o determin e whether th e yiel di n findin g significant

diseas e i s suffi

ciently high t o warran t

it s continuation
. Examinations

for occupational, medico-legal or insurance purposes (202) Examination s carrie dou t t o asses s th e fitnes s of an individual fo r

work , t o provid e informatio n for

medico-lega

l purposes , o r

t o asses s th e healt

h of asubscribe r

to , o r bene

ficiar y of , a n insuranc e ma

y carr y som e direc t o r indirec t advantage s fo r

th e individual examined , bu t

the y als o carry advantage s for th e employer , thir dpartie s an dth e insurer
. Al l thes e aspect s shoul db e considere di n assessin g th e justificatio n of suc h examina

tions
. Medical research (203 ) Examination s o r

treatmen t

formin g par t o f amedica l researc h progra msometime s involv e direc t

benefit s for

th e expose dindi

vidual an dsometime s d o not
. Whe n ne w an d experimental method s of

diagnosi s o r

treat
ment ar e capabl e o f

benefittin g th e patient s o n whomthe y ar e tested , th e justificatio n for th e procedure s ca

n b e judge di

n th e same wa

y a s fo r othe r medica l exposures . Nevertheless , becaus e o f th e experimental characte r of th e procedures , they shoul db e subjec t t o thor

oug h review
. (204 ) Th e deliberat e irradiatio n o f person s fo r th e purpose s oi studie s i n whic h n c son s irradiate di s i ; whe n th e exposure they ma y have , sh o properl y qualified ; irradiatio n shoul d consent o f th e au t institutio n wher

e t place , a s advise dI body an dsubjec t

to tions
. Th e estimat

e shoul db e explain e shoul db e volume

thei r free will
. Th e rigorou s shoul db e condition s o

f secur : thei r capabilit y o f follow s tha t

th e irr ; o f suc h studies , o

f c regarde da s bein g tru e consent

shoul d expecte dradiaiio n orde r of one-tent f limit s applicabl e t o public ) an di

f vali di thos e legall

y resp o Th e individual s ex

j tion s obtai n n o d exposure andir

. i s ensure tha t

thei r d able , an dthu s t o se ever , th e magnitu d ate dwit h th e expos i th e stat e of

healt h < an di t i s no t possib applicability
. App therefor e b e auth c program . The optimization q (205 ) Th e Cor

r emphasiz e that

care : would , in man y cas e reductio n of

th e do ; ures , withou t

impa i general , th e techni c shoul dallow :RECOMMENDATION S O F TH E ICR P 3 7 ee n th e advantage s s examine dan dfor : , togethe r wit h th e t , of th e screening
. ; wil l depen don th e ocedure , th e possi

nen t of th e case s liseases , th e advan

f th e contro l of

th e screenin g ar e no t en t group s makin g eening will ofte n b e '
. t o certai n specifie d oul d b e subjec t

t o determin e whether :an t diseas e i s suffi

ontinuation
. ional, medico-legal iedou t t o asses s th e > r work , t o provid e ga l purposes , o r

t o •cribe r to , o r bene

t y carr y some direc t fo r th e individual irr y advantage s for e s an dth e insurer , b e considere di

n o f suc h examina

treatmen t formin g Togra msometime s th e expose dindi

ot
. When ne

w an d diagnosi s o r

treat
Tittin g th e patient s h e justificatio n fo

r e din th e same wa

y ires
. Nevertheless , a l characte r

o f th e > e subjec t t o thor

diatio n of person s for th e purpose s of

thos e researc h an dothe r studie s in whic h n o direc t

benefi t t o th e per son s irradiate di s intended , i n circumstance s whe n th e exposure i s unrelate dt o any illnes s the y ma y have , shoul donl y b e undertake n by properl y qualifie dan dtraine dpersons . Suc h irradiatio n shoul donl y b e give n wit h th e consent o f th e authoritie s i n charg e of th e institutio n where th e irradiatio n i s t o tak e place , a s advise dby an appropriat e exper t bod y an dsubjec t

t o loca l an dnationa l regula

tions
. Th e estimate drisk s o f th e irradiatio n shoul db e explaine dt o thos e involved , wh o shoul db e volunteer s full y abl e t o exercis e thei r fre e will
. Th e higher

th e dos e th e mor e rigorou s shoul db e th e requirement s o n th e condition s of

securin g tru e volunteer s an do n thei r capability of

understandin g th e risk. I t
• follow s tha t

th e irradiation , for

th e purpose s o f suc h studies , of

childre n an dothe r

person s regarde da s bein g incapabl e o f giving thei r tru e consen t

shoul donl y b e undertake n i f th e expecte dradiatio n dos e i s low (e.g
. of th e order o f one-tent h o f th e dose-equivalent limit s applicabl e t o individual member s o f th e public ) an di

f vali dapprova l ha s been give n b y thos e legally responsibl e for suc h persons . Th e individual s expose dunde r thes e condi

tion s obtai n n o direc t

benefi t fro mthei r exposure an di t

i s therefor e necessar

y t o ensure tha t

thei r detrimen t

remain s accept
able , an dthu s t o se t

authorize dlimits
. How

ever , th e magnitud e of

th e detrimen t

associ

ate dwit h th e exposure depend s o n th e ag e an d th e stat e o f

healt h o f th e expose dindividual an di t i s no t possibl e t o fix limit s of

genera l applicability
. Appropriat e limit s shoul d therefore b e authorize dfor eac h researc h program . The optimization of

exposure (205 ) Th e Commissio n wishe s t o re emphasiz e tha t

carefu l attentio n t o technique s would , i n many cases , resul t

i n aconsiderabl e reductio n of

th e dos e du e t o medica

l proced

ures , withou t

impairmen t

of their value
. In general , th e technique s an dequipmen t used shoul dallow : th e reductio n of th e dose s receive db y tissue s i n th e regio n of

th e bod y unde r examinatio n t o th e minimu mcompatibl e wit h obtainin g th e necessar

y informatio n in th e particular

patient ; th e deliver

y t o th e treate dregio n o f th e bod y of atherapeuti c dos e th e magnitud e of whic h i s mos t

likely t o ensure th e re quire dresponse ; th e limitatio n a s fa

r a s practicabl e o

f th e exposure o

f othe r part s o f th e body
. (206 ) Becaus e o

f th e ris k of radiatio n injur

y t o any embry o o r

foetus , th e possibilit

y o f pregnanc y i s on e o f

th e factor s t o b e con sidere di n decidin g whethe r t o make aradio

logica l examinatio n involvin g th e lowe r abdome n i n awoman o f reproductiv e capacity
. Althoug h suc h a n examinatio n i s leas t likely t o pos e an y hazar dt o adevelopin g embry o if

carrie dou t

durin g th e 1 0 day interval followin g th e onse t of menstruation , attentio n shoul dalway s b e pai dt o detail s o f radiological techniqu e tha t woul d ensur e minimizatio n of

exposur e t o any embry o or foetu s tha t

ma y b e present , whether

o r no t th e women i s know n t o b e pregnant
. (207 ) Befor

e prescribin g an examinatio n or investigation , th e responsibl e practitione r shoul dsatisf

y himsel f

tha t th e necessar

y informatio n i s no t

alread y availabl e from othe r previou s examination s an dinvestiga

tions
. Professional

training (208 ) Th e Commissio n wishe s t o emphasiz e th e importanc e o f

includin g adequat e trainin g o n radiatio n protectio n in th e general educa

tio n an dtrainin g o f

individual s enterin g th e medica l an dassociate dprofessions , sinc e al l thos e wh o ente r

thes e profession s ma

y b e involve di n prescribin g procedure s involvin g exposure t o ionizin g radiation
. Mor e thoroug h trainin g in radiatio n protectio n i s require db y thos e plannin g t o ente r

th e fiel d of radiolog y an db

y scientist s an dtechnician s assistin g i n th e medica

l use s of radiation
.P.4 5

3 8 RECOMMENDATION S O F TH E ICR P (209 ) Recommendation s an dmore detaile d informatio n o n th e protectio n o f individual s subjec t t o medica

l examination s o r

treatmen t an do n th e trainin g of th e medica

l professio n ar e include di

n ICRPPublications 15, 16 an d 17.

OTHE REXPOSURE S (210) A s aresul t

o f human activities , individual s i n th e populatio n ma y b e subjec t t o exposure t o many source s beyon dthos e giving ris e t o occupationa l exposure an d medica l exposure . Exposur e t o thi s wid e rang e of source s i s considere di

n th e followin g paragraphs
. (211 ) Th e variou s contribution s t o othe r exposure ma

y b e groupe dint o broa dcate
gorie s t o whic h th e genera l principle s o

f protectio n ma

y appl y bu t

which call fo

r differen t technical approaches : Thes e categorie s are : exposure du e t o th e dispersio n in th e en vironmen t of radioactiv e materials ; direc t exposure t o radiatio n source s use din industry , medicin e an dresearch ; exposure resultin g fromth e us e i n everyda y lif e o f widely distribute dproduct s contain

in g source s o f

ionizin g radiation ; exposure t o natura l source s of radiatio n an dt o practice s ir

i everyda y lif e tha t caus e a n increas e i n th e leve

l of dos e resultin g fromth e natura l backgroun do f radiation ; an d exposure du e t o th e us e o

f radiatio n source s in teaching
. The assessment

of exposure (212) I n orde r

t o appl y th e syste

mo f dos e limitatio n t o any practic e involvin g suc h exposures , i t

i s necessar

y t o asses s both th e individual dos e equivalent s an dth e collectiv e dos e equivalents
. Fo r

th e purpos e o

f compar in g individual dos e equivalent s wit h th e appropriat e limits , th e dose s fromth e norma l natura l radiatio n backgroun dar e no t include d(se e paragraph s 8 9 an d90)
. (213 ) Th e assessmen t of individual dos e equivalent ha s th e ai mo f

ensurin g tha t

th e exposure o f

each individual remain s withi n th e appropriat e limit s an dthi s assessment mus t therefore take int o accoun t no t only th e radiatio n resultin g fromth e practic e unde r consideratio n bu t

als o th e tota l exposure resultin g fromal l th e practice s tha t contribut e t o genera l exposure . Th e assessment o f collectiv e dos e equivalen t ha s a s it s mai n objec t th e appraisa l o

f th e justificatio n an d optimizatio n o

f th e exposure . Th e assessment ca n therefore b e carrie dou t

i n relatio n t o th e propose dpractic e alone
. (214 ) Th e exposure of

individual s depend s o n alarg e numbe r

o f factors , som e relate dt o their wa y o f lif e an dthei r

us e of th e environ

men t an dother s concernin g thei r biologica l characteristics
. I t

i s no t possibl e t o evaluat e thes e variable s for

eac h of th e expose d individuals , bu t

i t i s generall y possibl e t o identif y withi n a n expose dpopulatio n smaller group s comprisin g individual s wh o ar e broadl y comparabl e i

n respec t o f thos e characteristic s tha t

determin e thei r

exposure . (215 ) Th e dos e equivalent t o aspecified orga n o r tissu e i n agive n populatio n grou p wil l usuall y b e determine do n th e basi s o f a representativ e sample
. Th e sprea do f th e observe dvalue s wil

l b e a n indicatio n o

f th e homogeneit

y o f th e sample , an dthu s o

f th e group , an dwil

l provid e astatistical basi s fo r judgin g whether

th e grou p ha s been suitabl y defined
. (216 ) I t i s ofte n possibl e t o identif y populatio n group s wit h characteristic s causin g themt o b e expose dat ahighe r leve l than th e res t

ofth e expose dpopulatio n froma give n practice
. Th e exposure of thes e groups , know n a s critical groups , ca n the n b e useda s a measur e of th e upp < dose s resultin g fro

n When severa

l practi i ficantly t o th e expo s population , either

s i sively , th. e definitio i takeaccoun t

o f thes e (217 ) Whe

n th e r tim e o r th e exposui menta l contaminat i collectiv e annua l do s amaximu move

r ap procedur e continue s maximu mcorrespo r ment o f an equiiib r leve l resultin g fromi o f th e practice
. I

t i averag e dos e equiva

l tha t shoul db e comp ; in g dose-equivalen t

I (218 ) I t i s als o use) th e dose-equivalent collectiv e dose-eq

i Thes e ar e obtaine db : th e averag e dose-eq ; th e expose dpopuk
. dose-equivalen t

ra t where eac h o

f thes e r ; th e applicatio n o

f a specifie dtime , often tio n tha t al l reie v constant , th e annu e an dth e annua l colle

i the n reac h equilibr

i dose-equivalen t

c c collectiv e dose-equ i yea r o f practice
. T : remai n constan t

inci tio n o f th e practice , ditions , th e size o

f an dth e wa

y peopl e I n som e instances , assume dt o continu e allo w for th e annua l c t o reac h equilibriu : sufficient t o integr

r equivalen t rat e ove r t a s thi s integra l i s cRECOMMENDATION S O F THE ICR

P 3 9 i e medica l professio n iblications 15,16

an d

t o f individual dos e of ensurin g tha

t th e dua l remain s withi n an dthi s assessment accoun t no t only th e i th e practic e unde r th e tota l exposure ctice s tha t contribut e Th e assessment

o f en t ha s a s it s mai n th e justificatio n an d sure . Th e assessment ou t i n relatio n t o th e individual s depend s tors , som e relate dt o i r us e of th e environ

in g thei r biologica l possibl e t o evaluat e c h o f th e expose d enerally possibl e t o dpopulatio n smalle

r dividual s who ar e i respec t o f thos e nin e their exposure , alent t o aspecifie d n populatio n grou p e don th e basi s o

f a Th e sprea do f

th e a n indicatio n o

f th e pie , an dthu s o

f th e i statistical basi s fo

r ip ha s bee n suitabl y ossible t o identif

y it h characteristic s >e d a t ahighe r leve l dpopulatio n fro

ma ur e o f thes e groups , ca n the n b e use da s a measure o f th e upper

limi t of th e individual dose s resultin g fromth e propose dpractice
. Whe n severa l practice s ma

y contribut e signi

ficantly t o th e exposure o f th e same expose d population , either

simultaneousl y or

succes sively , th e definitio n of

critical group s mus t tak e accoun t of thes e separat e contributions
. (217 ) When th e procedur e i s extende di n tim e o r th e exposure result s fromenviron

menta l contamination , th e individual an d collectiv e annua l dos e equivalent s ma y ris e t o amaximumove

r aperio do f

year s eve n i f th e procedure continue s a t

aconstan t

level
. Thei r maximumcorrespond s either t o th e achieve

men t o f a n equilibriu mconditio n or t o th e leve l resultin g fro

mth e perio dof

applicatio n o f th e practice
. I

t i s thi s maximumof

th e

. averag e dos e equivalen t

i n th e critical group s that shoul db e compare dwit

h th e correspond

ing dose-equivalen t

limit
. (218 ) I t i s als o useful i

n some case s t o asses s th e dose-equivalen t

commitmen t

or th e collectiv e dose-equivalen t commitment
. Thes e ar e obtaine db

y integratin g ove

r al l time th e averag e dose-equivalen t rat e throughou t th e expose dpopulatio n an dth e collectiv e dose-equivalent

rat e in tha t

population , wher e each o f thes e rate s i s that

resultin g from th e applicatio n o

f aspecifie dpractic e for

a specifiedtime , often ayear . On th e assump tio n that al l relevan t

condition s remai n constant , th e annua l mea n dos e equivalen t an dth e annua l collectiv e dos e equivalent wil l the n reac h equilibriu mvalue s equal t o th e dose-equivalent

commitment

an dth e collectiv e dose-equivalent commitmen t

pe r yea r o f practice
. Th e factor s that hav e t o remai n constan t

includ e th e rat e of

applica

tio n of th e practice , th e environmental con ditions , th e siz e o

f th e expose d populatio n an dth e wa

y peopl e us e tha

t environment
. I n some instances , th e practic e canno t b e assume dt o continu e fo

r asufficien

t tim e t o allo w fo r th e annua l collectiv e dos e equivalent to reac h equilibrium
. I

n thi s case , i

t i s sufficien t t o integrat e th e collectiv e dose

equivalent rat e ove r th e perio do

f th e practice , a s thi s integral i s equa

l t o th e maximu m annua l collectiv e dos e equivalen t t o b e experi

ence di n th e futur e fro mth e practice
. (219 ) Becaus e o f

it s complexity , assess ment s o f collectiv e dos e equivalen t

involv e th e us e o f simplification s an dapproximations , particularl y whe n alarg e populatio n i s irradi

ate da t lo w dos e levels
. Becaus e of this , the y ma y involv e considerabl e uncertaintie s an d thes e mus t

b e born e in min dwhe

n th e assess ment s ar e bein g use dt o apprais e th e detrimen t associate dwit

h apractice
. The restriction of

exposure The release of

radioactive materials into the environment. (220 ) Th e restrictio n o f th e exposur e whic h i s cause dby th e releas e o f radioactiv e material s int o th e environmen t depend s on : th e contro l o f

release s o f

gaseou s an d liqui d effluent s t o th e environment ; th e contro l o f

disposal s t o th e environmen t o f soli dwastes ; appropriat e arrangement s for reducin g th e probabilit y o f

accident s givin g ris e t o th e release s o f

radioactiv e material s int o th e environmen t

an dfor limitin g th e magni

tud e o f thes e releases , shoul dthe y occur . (221 ) Excep t

for trivia l amount s of

activity , al l release s o f

radioactiv e substance s t o th e environmen t

(includin g th e disposa l o f soli d wastes ) shoul db e subjec t t o authorization s issue db y th e competen t

nationa l authority
. Thes e authorization s shoul db e base do n pre operationa l studie s whic h should , i f neces sary , includ e th e assessment o f th e dose

equivalen t

commitmen t

t o differen t populatio n group s and , i n particular , t o th e critica l group , an dth e collectiv e dos e equivalent s an dcollectiv e dose-equivalen t commitments
. Thes e studie s shoul db e carrie dou t

a t a n earl y stag e of

aprojec t whe n i t i s stil l possibl e t o introduc e modifications
. (222 ) Thes e assessment s requir e th e us e o f model s o f

variou s degree s o f

complexity , representin g th e movement o f radioactiv e material s throug h th e environmen t fro mth eP.4 7

4 0 RECOMMENDATION S O F TH E ICRP sourc e t o man . Thes e model s hav e t o take int o accoun t th e natur e arid : the " physica l an d chemica l form s o f th e radioactiv e materials , togethe r wit h thei r method s o

f release
. Th e model s the n hav e t o reflec t th e characteristic s o f th e environmen t

an dof ma n that influenc e th e consequen t

exposure of

individual s an d groups . T o mak

e suc h model s detaile dan d realisti c require s extremely complex studie s involvin g aconsiderabl e effort , an di t i s reasonabl e i

n practic e t o adjus t

th e magnitud e o f thi s effor

t t o th e importanc e of

th e particular problem. * (223 ) In practice , th e firs t

stag e i s t o carr

y ou t asimplifie dpreliminar

y study base don existin g informatio n an dmakin g us e o f reasonabl y cautiou s hypothese s t o bridg e ove r th e gap s in th e informatio n tha t alway s exis t at thi s stage
. I n almos t

al l situation s th e preliminar y study wil

l sho w tha t

th e exposure s tha t

might b e cause db

y th e propose drelease s ar e extremel y lo w an dtha t sufficien t informatio n already exist s for makin g decisions
. I n some cases , however , th e preliminar

y stud y wil

l indicate th e need for further work , usuall y of

limite dscale
. (224 ) When i t

appear s tha t

th e exposure s wil l b e significant , i t

wil l usuall y b e necessar

y t o asses s the mwit

h greate r accurac y an dt o carr y ou t more detaile dstudie s directe d principall y a t

reducin g th e uncertaintie s indicate dby th e preliminary study
. (225 ) Th e relationshi p between th e rat e of releas e an dexposure o

f th e critical grou p allow s th e assessment

of aderive dlimit

of releas e i n eac h case . (226 ) Th e authorize dlimit s o f releas e ar e fixe db y th e nationa l authoritie s a t value s which ar e generall y lowe

r tha n thos e of

th e derive dlimits
. I n settin g such limit s th e authoritie s shoul dapply , wit h an appropriat e degre e of detail , th e processe s o f

optimiza

tion, an dshoul dtak e accoun t o f othe r curren t o r propose dsource s of

exposure . (227 ) Becaus e of

th e different

factor s considere di n th e proces s of optimization , th e authorize dlimi t fo r th e tota l releas e t o a secto r o f th e environmen t

t o which severa

l installation s releas e radioactiv e material s ma y b e differen t

fromth e su

mof th e opti

mizedlimit s appropriat e for eac h installatio n separately
. When severa

l installation s make release s int o th e same secto r of th e environ

ment , fo r exampl e int o th e same rive r basin , i t i s necessar

y t o asses s th e derive dlimi t of releas e for th e whol e ofth e relevant

sector
. Direct external exposure from sources used for industrial, medical

or scientific purposes. (228 ) Th e restrictio n o

f exposure i

n thes e case s i s usuall y achieve dwit

h th e ai do

f technica l standard s relatin g t o th e sources . In som e cases , however , th e restrictio n of exposure ma y for mpart of th e desig n o

f th e individual project
. An y necessar

y reductio n of

exposure i s usuall y obtaine db

y th e us e o f shielding , bu t exceptionall y i t

ma y b e necessar

y t o defin e a

n are aof restricte dacces s o r

us e i n th e vicinit

y ofth e source . The use of

products widely distributed to thepublic. (229 ) It

i s convenient

t o distinguis h between tw o categorie s of

suc h products : thos e whic h includ e electroni c equipmen t tha t emit s x ray s adventitiously ; thos e which contai n radioactiv e materials
. (230 ) Thes e tw o categorie s of produc t presen t different problem s i

n th e restrictio n o f exposure . Th e firs t

categor y give s ris e only t o external irradiatio n an dtha t only durin g operations
. Fo r

th e secon dcategory , i

t i s als o necessar y t o tak e accoun t

of th e possibilit

y of contaminatio n resultin g fromnorma l use , abnorma l event s an ddisposal
. (231 ) Th e restrictio n o

f exposure fromboth thes e categorie s o f

produc t shoul db e base d o n acontro l syste

ma t th e nationa l leve

l aime d a t ensurin g that

th e exposure s cause db

y eac h produc t ar e justifie dan dthe n limite di n a n appropriat e way . Th e appraisa l o f th e conse quence s o

f th e us e o

f thes e product s i s jgmeiiaiH y base dc (DsU'eKXtiv e dos e eq u amsQim e applicati o tD3 > tatk e accoun t fflspiwaients. Th e c gjjwai i applicatio n flesliuires o

f th e de dfasiio e 'o f th e ra d Hnnronilkictiio

n of sh i 0£33Mt:i s often t arjjarrriicula

r appiic r sna^ U whil e the r

e wnysenafi
. it-i s th

e qsaaanttitativ

e appr a Jfint e ffiinal decisio n agmaiiiittat i v e j udgme : ((S3 ) Althoug h ffirann -eac

h typ e o l garasdiiict s ar e us t aastdhflark y shoul de nesaiMn g froma

l ttmgsEtdine r remai n wi i fteaocepta'bie. ((2Sft)The-pr,acti

c ffiranmn iproduct s w l annttflsairized

, .-i s ach i ffiarihnical .standard s teamsttiics o f

:th e pro < wikffl n tthe conditi c snniffilliitmes, ib

y pre tfflmiireventuiv

i disp o Ftoectiaes raising wdnma'i badkgroun, pnaeaiice s tha t

m a exposur e fro mth

e laafianknvinclude :

•Thi s lopk - i s discusse d in detai l in a repor tbein g prepare d b

y ICR P Committe e 4 . :aaseo l certai n ttaamuD f buildings
. Kaititude fly

i : consumptio n fimwihich thecon c eflamnent s is.unus i ffiriigin or

ha s be e %/ttih e us e o f fert
. (Q36 J I n applyin g i t i s ap pRECOMMENDATION S O F TH E ICR P 4 1
e tota l releas e t o a en t t o whic h severa l adioactiv e material s th e su mo f

th e opti

- • fo r eac h installatio n a l installation s mak e ecto r o f th e environ

he sam e rive r

basin , i t th e derive dlimi t

o f a e relevan t

sector
. 're from sources used r scientific purposes. \posur e i n thes e case s th e ai do f

technica l i e sources . I n som e trictio n o f

exposur e sign o f th e individua l eductio n o f

exposur e : us e o f shielding , bu t ecessar y t o defin e a n o r us e i n th e vicinit y videly distributed

to 'enien t t o distinguis h f suc h products : lectroni c equipmen t titiously ; dioactiv e materials
. egorie s o f

produc t n s i n th e restrictio n egor y give s ris e onl y n dtha t onl y durin g i d category , i t

i s als o : o f th e possibilit y o f fro mnorma l use , osal
. exposur e fro mbot h ic t shoul db e base d nationa l leve l aime d ;ure s cause db y eac h I the n limite di n a n praisa l o f th e conse thes e product s i s generall y base do n th e magnitud e o f th e collectiv e dos e equivalen t tha t the y cause , bu t i n som e application s i t

ma y als o b e necessar y t o tak e accoun t

o f th e individua l dos e equivalents
. Th e exposur e resultin g fro ma give n applicatio n ca n ofte n b e reduce db y feature s o f

th e desig n (fo r

example , b y th e choic e o f

th e radionuclid e use do r b y th e introductio n o f

shieldin g agains t

x rays)
. (232 ) I t i s ofte n th e cas e tha t

th e benefit s o f aparticula r

application , thoug h real , ar e ver y small , whil e th e resultin g exposure s ar e als o very small
. I t

i s the n ver y difficul t

t o mak e a quantitativ e appraisa l o f th e situation , an d th e fina l decisio n wil l ofte n b e base do n qualitativ e judgment
. (233 ) Althoug h th e exposure s resultin g fro meac h typ e o f

thes e widel y distribute d product s ar e usuall y low , th e nationa l authorit y shoul densur e tha t th e exposure s resultin g fro mal l th e application s take n togethe r remai n withi n limit s tha t i t judge s t o b e acceptable
. (234 ) Th e practica l restrictio n o f exposures , fro mproduct s whos e us e i s justifie dan d authorized , i s achieve db y complianc e wit h technica l standard s dealin g wit h th e charac

teristic s o f

th e product s and , i n som e cases , with th e condition s o f thei r us e and , sometimes , b y providin g arrangement s fo r thei r eventua l disposal
. Practices raising the level of exposure to natural background. (235 ) Example s o f th e practice s tha t

ma y increas e th e leve l o f exposur e fro mth e natura l backgroun do f radiatio n include : th e us e o f certai n material s i n th e construc
tio n o f building s an droads ; high-altitud e flying ; th e consumptio n o f

wate r an dfoodstuff s i n whic h th e concentratio n o f natura l radio

element s i s unusuall y hig h becaus e o f thei r origi n o r ha s bee n enhanced , fo r exampl e b y th e us e o f

fertilizers
. (236 ) I n applyin g th e syste mo f limitatio n o f exposure , i t

i s appropriat e t o tak e accoun t onl y o f th e chang e i n exposur e cause db y (th e assesse dpractic e an dno t o f th e pre-existtiim

g exposur e level
. Th e justificatio n fo r mos t o f th e underlyin g practice s (suc h a s tdhs e comsitroc

tio n o f buildings ) i s self-evident , am i th e emphasi s i n th e restrictio n o f exposur e i s therefor e o n optimization
. Th e pmoces s o f optimizatio n usuall y lead s t o tthe estabfch

men t o f authorize dlimit s fo r

eac h significan t situation
. The use of

radiation sources in mucking. (237 ) I t i s importan t

t o distinguis h betwee n tw o kind s o f

application s o f

radiation source s i n teaching : th e genera l teachin g o f

sciencesubjeclis ; specialize dteachin g o f

subject s concerne d wit h radiation s an dthei r uses . I n th e first

typ e o f applicatio n th e exposur e resultin g fro mdemonstration s o r experiment s i s likel y t o involv e aver y larg e mutmbe r o f peopl e an dmigh t

thu s contribut e signifi

cantl y t o th e genera l exposure . Fo r thi s treaso n th e Commissio n recommend s tha t th e annua l dos e equivalent s receive db y indivMma l pupil s durin g thei r

course s shoul dno t

excee done tent h o f th e limit s recommende dfo r individua l member s o f

th e public
. Th e secon dttype o f applicatio n involve s amuc h smalle r numbe r o f peopl e an di s analogou s t o occupationa l exposure . Onl y exceptionall y wil l th e us e o f radiatio n source s i n thi s kin do f teachin g requir e th e condition s o f wor k t o b e dassifie d a s Workin g Conditio n A (se e paragrap h 161)
. Workin g Conditio n A shoul db e pantnitte d onl y wher e student s ar e age d1 8 year s o r over . Th e genera l procedure s fo r restricting exposur e shoul db e broadl y simila r t o thos e fo r occupationa l exposur e although , i n th e absenc e o f

Workin g Conditio n A , the y ca n b e substantiall y simplified
. Mor e detaile d recommendation s ar e give n i n ICRPPublication 13. Monitoring of

exposure Monitoring in normal

conditions. (238 ) Release s o f

radioactiv e material s int o th eP.4 9

4 2 RECOMMENDATION S O F TH E ICR P environmen t

shoul db e subjec t

t o appropriat e monitorin g t o demonstrat e complianc e wit h th e authorize dreleas e limits , unles s othe r form s of assessment

show thi s monitorin g t o b e unnecessary . Fo r

majo r installations , th e monitorin g o f

release s ma

y als o contribut e t o th e detectio n o f

abnorma l situations
. I

n mos t othe r cases , th e monitorin g o

f source s shoul d b e aime da t

ensurin g complianc e wit h technical standard s an d th e arrangement s require db y th e nationa l authorities
. Specia l requirement s may deal , for example , wit

h th e effectivenes s o f

shield s aroun dsources , th e characteristic s o f

consumer

product s an dth e monitorin g o f

contro l of thei r distribution , o r th e settin g o f

activit y limit s for

buildin g materials
. (239 ) I n afe

w cases , essentiall y limite dt o situation s wher

e th e exposure result s fro

mth e releas e of radioactiv e material s int o th e environment , i t

ma y b e necessar

y t o supple

men t th e monitorin g o f

source s b y monitorin g o f th e relevant

secto r of th e environment
. Suc h monitorin g ma

y als o b e useful i n verify

in g th e validit

y o f th e model s use di

n predict

in g exposure . Th e introductio n of environ

mental monitorin g i s only necessar y i n th e fe w case s where preoperationa l studie s hav e show n tha t

th e installatio n migh

t b e th e caus e o f asignificant

exposure of

member s of

th e public
. Situation s ma

y als o aris e wher

e severa l installation s ma

y releas e radioactiv e material s int o th e sam e secto r of th e environ

men t and , eve n if eac h i s individuall y insigni

ficant , the y ma

y togethe r mak e i t necessar y t o introduc e aprogra mof environmental monitoring , usuall y of

alimite dnature
. (240 ) Individua l monitorin g will no t normall y for

mapar t o f th e monitorin g o

f general exposure of

th e public , excep t

i n relatio n t o som e aspect s o f th e us e of radiatio n source s i n teaching
. I n th e special

izedteachin g associate dwit h th e character

istic s o r us e o f radiatio n sources , individual monitorin g ma

y b e justifie dby th e likel y level s o f exposure o r

b y th e fact

tha t i t form s a valuabl e introductio n t o goo dpractic e in subsequen t

work
. Monitoring in abnormal circumstances. (241 ) In abnorma l circumstance s following , for example , a

n acciden t i n a n installatio n or durin g transport , i t

ma y b e necessar

y t o carr y ou t monitorin g if

radioactiv e material s ma y hav e bee n release dint o th e environmen t i n quantitie s capabl e o f

causin g asignificant exposure of

member s of

th e public
. Thi s monitorin g ha s th e principal objectiv e of obtainin g informatio n necessar y t o asses s th e situatio n an dt o decid e o n th e nee dfor inter

vention
. I t

shoul dals o provid e dat afor th e evaluatio n of

th e exposure of

member s of

th e public , takin g accoun t

of any counter
measure s tha t

hav e been applied
. Further

more , scientifi c informatio n shoul dals o b e collecte dwit

h th e ai mof

improvin g th e predictio n o f

consequence s in suc h situations
. Th e programof

monitorin g shoul db e designed , a t

leas t i n general terms , whe

n a n installatio n firs t

become s operationa l o r a serie s of transpor t

operation s i s firs t considered
. Intervention (242 ) Th e for

mo f interventio n suitabl e for limitin g a n abnorma l exposure t o member s o f th e publi c will depen do n th e circumstances
. All th e countenneasure s tha t can b e applie dt o reduc e th e exposure o f

member s of

th e publi c after a n accidental releas e o f

radioactiv e material s carr

y som e detrimen t

t o th e peopl e concerned , whether

i t i s aris k t o healt h or som e socia l disruption
. Th e decisio n t o introduc e countermeasure s shoul db e base d o n abalanc e of

th e detrimen t

which i t carrie s an dth e reductio n i n th e exposur e which i t can achieve
. Th e magnitud e o f th e detrimen t

o f countermeasure s wil

l var y wit h thei r natur e an dwit h th e circumstance s i n whic h they ar e applied , for

example , wit

h th e siz e of

th e populatio n involved
. Thei r effectiveness , on th e othe r hand , will depen do n th e spee dwit h which they can b e introduced
. Fo r thes e reason s i t i s no t possibl e t o fi

x generall y applicabl e interventio n level s abov e whic h interventio n will alway s b e required
. How

ever , i t migh t b e whic h interventi considere dt o be
. depen do n th e j eac h cas e an dca

i guidance
. Th e d e measure s should' : informatio n ava

i tionieveisareex p dos e equivalent s helpfu l i n practi c ventKo n level s ap i measurement s f

c monitorin g progr : (243)T o be,eff

. pre-planned
. A

n therefor e b e prep : menrsber s o f th e i sigtiM'dcan t accide genc y plan sfooul

d tihe special mo n Sffituatio u (se e p a tia e countcrme a.'«

- fsss*
. V *

RECOMMENDATION S O F TH E ICR P 4 3 mal circumstances. mstance s following , i n an installatio n o r ) e necessar

y t o carr y ctiv e material s ma

y th e environment

i n usin g asignificant ) f th e public
. Thi s ncipa l objectiv e o

f cessar y t o asses s th e n th e needfor

inter

irovide dat afor

th e e of member s of

th e of any counter
aapplied
. Further

tio n shoul dals o b e o f improvin g th e cs in suc h situations , itorin g shoul db e :ral terms , whe

n an : s operationa l o r

a peration s i s first ever , i t might b e possibl e t o set

level s belo w which interventio n woul dno t generally b e considere dt o b e justified
. Interventio n level s depen do n th e particular circumstance s of each cas e an dca

n therefor e give only genera l guidance
. Th e decisio n t o introduc e counter
measure s shoul db e take n in th e ligh t of al l th e informatio n availabl e a t

th e time
. Interven

tio n level s ar e expresse di

n term s o f individual dos e equivalent s o r

intakes
. I

t wil l ofte n b e helpful i n practic e t o provid e derive dinter

ventio n level s applicabl e t o th e result s of th e measurement s formin g part o f th e specia

l monitorin g program . (243 ) T o b e effective , interventio n mus t b e pre-planned
. A n emergenc y pla n shoul d therefore b e prepare din any situatio n where member s of

th e publi c ma

y b e subjec t

t o a significant accidental exposure . Th e emer gency plan shoul dinclude : th e specia l monitorin g neede dt o asses s th e situatio n (se

e paragrap h 241) ; th e countermeasure s neede dt o reduc e th e exposure of member s of

th e publi c togethe r wit h th e mean s necessar

y t o pu t the mint o effect ; th e interventio n level s an dderive diMer

ventio n level s givin g guidanc e o n th e differ

en t countermeasures
. Th e emergenc y plan shoul db e base d io n a study o f th e radiological consequence s © f th e release s followin g areferenc e accident
. Thes e consequence s shoul db e assesse drasing a metho danalogou s t o tha t describe di

n paragraph s 222-23 4 for release s dnnrin

g norma l operations
. Th e plan shoul db e seffi

ciently flexibl e t o allo w it s adaptatio n 5 © th e rea l situation , sinc e thi s wil

l differ firaam-tha t forecast
. I n particular , th e inverventiomfisvei s an dth e derive dinterventio n level s shom M no t b e applie dautomatically ; the y shoul db e treate da s referenc e level s intendedfo r guidanc e in makin g decision s an dsfoonuD d b e reassesse din th e light

of al l th e availabl e informatio n at

th e time o f intervention
.
ventio n suitabl e for osur e t o member s o

f I th e circumstances , ha t ca n b e applie dt o •mber s of th e publi c as e of radioactiv e imen t t o th e peopl e aris k t o healt h o r Th e decisio n t o e s shoul db e base d len t which i t carrie s tposure which i

t ca n o f th e detrimen t

of y wit h thei r natur e e s i n whic h the y ar e it h th e size o

f th e •i r effectiveness , o n i d o n th e spee dwit

h oduced
. Fo r

thes e l e t o fix-generall y evel s abov e whic

h b e required
. How

-RECOMMENDATION S O F TH E ICR P 4 5



### APPENDI X

Rules governing the selection and work of the Commission Th e followin g ar e th e Commission' s rules , a s approve db y th e Internationa l Congres s of Radiology
. 1
. (a) Th e Internationa l Commissio n o n Radiological Protectio n (ICRP ) shal l b e com pose dof aChairma n an d no t

mor e tha n twelv e othe r members
. Th e selectio n o f th e member s shal l b e mad e b y th e ICR

P fro mnomination s submitte dt o i t

b y th e Nationa l Delegation s t o th e Internationa l Congres s of Radiolog y an d by th e ICR P itself

. Th e selection s shal l b e subjec t t o approva l b y th e Internationa l Executiv e Committe e (IEC ) o f th e Congress
. Member s of

th e ICR P shal l b e chose n o n th e basi s o f thei r recognize dactivit

y i n th e field s o f medica l radiology , radiatio n protection , physics , healt

h physics , biology , genetics , biochemistr

y an dbiophysics , wit

h regar dt o a n appropriat e balanc e of expertis e rathe r than t o nationality
. (b ) Th e membershi p of

th e ICR P shal l b e approve d durin g eac h Internationa l Congress , fo r servic e unti l th e en dof th e succeedin g Congress , o r

unti l ne w member s ar e ap pointed
. No t

les s than thre e bu t

no t mor e than fiv e member s shal l b e change dat any on e Congress
. I n th e intervenin g perio dvacancie s ma y b e filledb

y th e ICRP
. (c ) I n th e event

of amembe r of th e ICR P bein g unabl e t o atten dth e ICR P meetings , a substitut e ma

y b e selecte db

y th e ICR P a s a temporary replacement
. Suc h asubstitut e shal l no t hav e votin g privilege s unles s specifi

cally authorize d b

y th e ICRP
. (d ) Th e ICR P shal l b e permitte dt o invit e individual s t o atten dit s meeting s t o give specia l technical advice
. Such person s shal l no t hav e votin g privileges , bu t thei r opinion s ma y b e recorde din th e minutes
. 2
. Th e Chairma n shal l b e electe dby th e ICR P fro mamon g it s member s t o serv e unti l th e en dof th e succeedin g Congress , o r unti l hi s successo r

i s elected
. Th e choic e shal l no t b e limite dt o th e country in whic h i t i s propose d t o hol dth e succeedin g Congress
. Th e Chair

ma n shal l b e responsibl e for reportin g th e proceeding s an drecommendation s of th e ICR P a t th e next Congress
. 3
. Th e ICR P shal l elec t

fro mamon g it s member s aVice-Chairman wh o wil l serv e i n th e capacit

y of Chairma n i n th e event

tha t th e Chairma n i s unabl e t o performhi s duties
. 4
. Minute s of

meeting s an drecord s of

th e ICR P shal l b e mad e b y aScientifi c Secretary selecte db y th e Chairma n o f th e ICRP , subjec t t o th e approva l of

it s members
. Th e Scientifi c Secretar

y nee dno t

b e amembe r

o f th e ICRP
. Th e record s o f th e ICR P shal l b e passe do n t o th e succeedin g Scientifi c Secre

tary
. 5
. Th e Chairman , in consultatio n wit h th e Vice-Chairman an dth e Scientifi c Secretary, shal l prepar e aprogramt o b e submitte dt o th e Commissio n for

discussio n at

it s meetings
. Proposal s t o b e considere dshal l b e submitte d t o th e Chairma n for

circulatio n t o al l member s of

th e ICR P an dothe r

speciall y qualifie dindividual s a t

leas t 2 month s befor e any meetin g o

f th e ICRP
. 6
. Decision s o f

th e ICR P shal l b e mad e b y a majorit y vot e of th e members
. A minorit y opinio n ma

y b e appende dt o th e minute s o f a meetin g i f s o desire db

y an y member

upo n hi s submissio n of

th e same i

n writin g t o th e Scientifi c Secretary
. 7
. Th e ICR P ma

y establis h suc h committee s a s i t deem s necessar

y t o perfor

mit s functions
.P.5 2

•4 6 'MettLmmtrship Th e Commission' s rule s requir e tha t it s member s b e electe dever y 4 years . Th e C
. G
. STEWART , Chairman B . LlNDElX

, Vice-Chairman D
. J
. BENINSO N H I JAMME T J L LlNlECK I A
. X MCLEA N Y
. f
. MOSKALE V H. B
. NEWCOMB E djamrnttee I

on Radiation Effects A. C . UPTON , Chairman S L ABRAHAMSO N G
. W
. BARENDSEN S. M. BROW N A
. M
. BRUE S O
. Hu e (Dnamattee 2 on Internal Exposure k VENNART , Chairman W
. J
. BAI R G-. C l BUTLE R G t W
. DOLPHI N l_
. E

_FEINENDEGE N W
. JACOB I Ghummittee 3 on External Exposure VL LlNDELL

, Chairman A
. K.ELLERE

R E
. E
. KOVALE V L.-E
. LARSSO N C MEINHOL D RECOMMENDATION S O F TH E ICR P
membershi p o f

th e Commissio n an d o f it s committeesfo r

1973-197 7 wa s a s follows : E
. E
. POCHI N S
. TAKAHASH I A
. C
. UPTO N J
. VENNAR T B
. WINDEYE R K. Z . MORGAN , MemberEmeritus L . S . TAYLOR , MemberEmeritus F . D . SOWBY , Scientific Secretary

B
. MODA N R
. H
. MOL E G
. MORLA T P
. OFTEDA L A.G
. SEARL E V
. ZELEN Y

J
. LAFUM A C
. MAY S P
. E
. MORRO W P
. V
. RAMZAE V W
. S
. SNYDE R R
. C
. THOMPSO N
R
. OLIVER , died

1976 P
. PELLERI N R
. A
. ROWLE Y K
. A STEVEN S S
. TAKAHASH I Method of Woi Muc h o f

th e Commissio n o i performe d b y a

c whic h theComr : th e service s o f

i wh o ar e no t

me t wa y th e Comm i th e appropriat e i s o tha t wor k a publishe d withi r i f th e Commiss i ensur e th e saf

e a technique s i n t
. information
. R

i lishe dar e show n Relationships w Th e Commis s shi p wit h th e Wc th e Internation ; Clos e workin g : taine dwit h th e Committe e o n t
. tion , th e Un i Programme , th e th e Intertnvtion E sion , th e Nncl e Europea n Gcon c missio n i s rep r numbe r o f m e bodies ; al l o f

th e

(Dmamttee 4

on Application of

the Commission's Recommendations M. JAMMET , Chairman ID
. J
. BENINSO N H..J-
. DUNSTE R K . K.ORE

N E
. KUN Z I>
. MECHAL I A
. A
. MOISEE V H
. MUT H C
. POLVAN I L
. ROGER S D
. J
. STEVEN S E
. G
. STRUXNES S K
. SUNDARA M.J.m£1&Li

RECOMMENDATION S O F TH E ICRP 47
issio n an dof

it s a s a s follows :

tent us ritus etary Method of Work Muc h of th e wor k of th e Internationa l Commissio n o n Radiological Protectio n i s performe db y ad

hoc tas k groups , by mean s of which th e Commissio n ha s been abl e t o cal l o n th e service s of

alarg e numbe r

o f individual s who ar e no t

member s of

acommittee
. I n thi s wa y th e Commissio n i s abl e t o brin g together th e appropriat e expert s rapidl y an deffectivel y s o tha t wor k ca n b e complete dan dreport s publishe dwithi n th e short

tim e tha t i s essentia l i f th e Commission' s recommendation s ar e t o ensure th e saf

e an drapi ddevelopment

of ne w technique s in th e light

of th e mos t

recent information
. Report s tha t hav e bee n pub

lishedar e show n at

th e end of th e appendix
. Relationships with other

bodies Th e Commissio n ha s a n officia l relation

shi p wit h th e Worl dHealth Organizatio n an d th e Internationa l Atomi c Energ y Agency
. Clos e workin g relationship s ar e als o main

taine dwit

h th e Unite dNation s Scientifi c Committe e o n th e Effect s of Atomi c Radia

tion , th e Unite dNation s Environmen t Programme , th e Internationa l Labou r Office , th e Internationa l Electrotechnical Commis

sion , th e Nuclea

r Energ y Agency an dth e Europea n Economi c Community
. Th e Com

missio n i s represente dby observer s a t a number of meeting s organize db y thes e bodies ; al l o f

th e abov e bodie s ar e invite dt o sendrepresentative s t o th e Commission' s meeting s wit

h it s committees
. Financial support Meeting s o

f th e Commissio n wit

h it s committee s ar e hel dapproximatel y ever y 2 years , an dth e Commissio n itsel f meet s abou t onc e ayear . In addition , committee s an dtas k group s mee

t o n thei r ow n t o discus s an d prepar e thei r

reports
. Th e Commissio n ha s been abl e t o suppor t

th e trave l cost s o

f some of th e individual s attendin g thes e meetings , thank s t o grant s of

mone y generousl y mad e t o i t by th e Worl dHealth Organization , th e Internationa l Atomi c Energ y Agency , th e Unite dNation s Environmen t Programme , th e Internationa l Societ

y o f Radiology , th e Internationa l Radiatio n Protectio n Associa

tion , th e Nuclea

r Energ y Agency , th e Euro

pea n Economi c Community , an dnationa l source s in Canada , Japa n an dth e Unite d Kingdom
. Nevertheless , th e contributio n tha t th e Commissio n ca

n make t o trave l expense s i s severel y limited , an ddurin g recent year s between one-hal f

an dtwo-third s of

th e tota l trave l cost s hav e been born e by th e institution s of th e ICR P members
. Th e Commissio n i s gratefu l for

th e amoun t

of time mad e avail

abl e t o it s wor

k b y th e institution s of

it s members , an dfo

r al l th e financia

l support , withou t which i t woul dno t

b e possibl e t o carr y ou t it s work
.RECOMMENDATION S O F TH E ICR P 4 9 

### PUBLICATION S O F TH E COMMISSIO N
1 . X-ray and

Radium Protection. Recommendation s o f th e 2n d Internationa l Congres s o f Radiology , 1928 . Circula r No . 37 4 o f

th e Bureau o f

Standards , U.S . Governmen tPrintin g Offic e (Januar y 23 , 1929) . Br. J. Radiol., 1 . 35 9 (1928) . 2 . Recommendation s o f th e Internationa l X-ra y an d Radiu m Protectio n Commission . Alteration s t o th e 192 8 Recommendation s o f

th e 2n d Internationa l Congres s o f Radiology . 3r

d Internationa l Congres s o f Radiology , 1931 . Br. J.Radiol.. 4,485(1931) . 3 . I nternationa l Recommendation s fo r X-ra y an d Radiu m Protection . Revise d b y th e Internationa l X-ra y an d Radi u m ProtectionCommissionandadoptedb y the3r d InternationalCongresso f Radiology , Paris , Jul y 193 1 Br. J. Radiol., 5,82(1932) . 4 . Internationa l Recommendation s fo r X-ray an d Radiu m Protection . Revise d by th e Internationa l X-ra y an d Radiu m ProtectionCommissionandadopte d by the4t h Internationa l Congresso f Radiology , Zurich , Jul y 1934 . Radiology, 23,6S2-5(\9.4).Br. J. Radiol., 7,695(1934) . 5 . Internationa l Recommendation s forX-rayandRadiu m Protection . Revisedb y th e InternationalX-ra y an d Radiu m Protectio n Commissio n an d adopte d b y th e 5t h Internationa l Congres s o f Radiology , Chicago , Septembe r 1937 . BritishInstituteofRadiology(1938) . 6 . Internationa l Recommendation s o n Radiologica l Protection . Revise d by th e Internationa l Commissio n o n Radiologica l Protectiona tthe6t h InternationalCongresso f Radiology , London , 1950 . Radiology, 56,43 1 - 9 (1951) . Br. J. Radiol.. 24,46-53(1951) . 7 . Recommendation s o f th e Internationa l Commissio n o n Radiologica l Protectio n (Revise d Decembe r I , 1954) . Br. J. Radiol., Suppl.6(1955) . 8 . Repor to n Amendment s durin g 195 6 t o th e Recommendation s o f th e Internationa l Commissio n o n Radiologics ^ Protectio n (ICRP) . Radial. Res., 8 , 539-54 2 (1958) . Acta Radiol., 48 , 493-49 5 (1957) . Radiology, 70 , 26I-2S 2 (1958)fb/75cArittea.d.Gebieted.Rontgenstrahlenu.d.Nuclearmedizin , 88,500-502(1958) . 9 . Recommendation s o f th e Internationa l Commissio n o n Radiologica l Protectio n (Adopte d Septembe r 9 , 1958) . ICRPPublication /,PergamonPress,London(1959) . 10 . Repor to n Decision s a tth e 195 9 Meetin g o f

th e Internationa l Commissio n o n Radiologica l Protectio n (ICRP) . Radiology, 74,116-119(1960) . Am. J. Roentg., 83,372-37 5 (1960) . Strahtentherapie, 112,3(1960) . Acta Radiol., 53,2{1960).Br.J.Radiol., 33,189-192(1960) . 11 . Recommendation s o f th e Internationa l Commissio n o n Radiologica l Protectio n (a s amende d 195 9 an d revise d 1962) . ICRPPublication6, Pergamo n Press , Oxford( l 964) . 12 . Recommendation s o f th e Internationa l Commissio n o n Radiologica l Protectio n Repor to f Committe e I

I o n Permissibl e Dos e fo r Internal Radiatio n (1959) . ICRPPublication2, Pergamo n Press , Oxfor d (1960) . Health Phys., 3,(1960) . 13 . Recommendation s o f th e Internationa l Commissio n o n Radiologica l Protectio n Repor to f Committe e II

I o n Protectio n agains tX-ray s u p t o Energie s o f 3 Me V an d Beta - an d Gamma-ray s fro m Seale d Source s (1960) . ICRP Publications, Pergamo n Press , Oxford ( 1960) . 14 . Recommendation s o f th e Internationa l Commissio n o n Radiologica l Protectio n Repor to f Committe e I

V (1953-1959 ) o n Protectio n agains tElectromagneti c Radiatio n abov e 3 Me V an d Electrons , Neutron s an d Proton s (Adopte d 1962 , wit

h revision s adopte d 1963) . ICRP Publication^ Pergamo n Press , Oxfor d (1964) . 15 . Recommendation s o f th e Internationa l Commissio n o n Radiologica l Protectio n Repor to f Committe e V o n th e Handlin g an d Disposa l o f Radioactiv e Material s i n Hospital s an d Medica l Researc h Establishments . ICRP Publications, PergamonPress,Oxford(l965) . 16 . Principle s o f

Environmenta l Monitorin g relate d t o th e Handlin g o f Radioactiv e Materials . A repor tprepare d by a Tas k Grou p o f

ICR P Committe e 4 , ICRPPublication 7, Pergamo n Press , Oxfor d (1966). * 17 . Th e Evaluatio n o f

Risk s fro m Radiation . A repor tprepare d b y a'Tas k Grou p o f ICR P Committe e I , ICRP Publications, Pergamo n Press , Oxfor d (1966) . Heallh Phys., 12,239-30 2 (1966) . 18 . Recommendation s o f th e Internationa l Commissio n o n Radiologica l Protection . (Adopte d Septembe r 17 , 1965) . ICRP

Publication 9, Pergamo n Press , Oxfor d (1966) . 19 . Reporto n amendment s t o ICRP Publication 9. Health Phys., 17 , 389-39 0 (1969) . Acta Radiol.. 8 , 25 8 (1969) . 20 . Reporto n th e 197 1 meetin g o f ICRP . Health Phys.. 21 , 615-61 6 (1971) . Phys. Med. Biol., 16 , 693-69 5 (1971) . 21 . Reporto n th e 1972 meetin g o f ICRP . Health Phys., 24.36 0 (1973) . Am. J. Roentg., 117,21 1 (1973) . 22 . Reporto f

Committe e 4 o n evaluatio n o f radiatio n dose s t o bod y tissue s fro m interna l contaminatio n du e t o occupationa l exposure . ICRP Publication 10, Pergamo n Press , Oxfor d (1968). * 23 . Th e assessmen to f

interna l contaminatio n resultin g fro m recurren to r prolonge d uptakes . A repor to f ICR P Committe e 4 . ICRP

Publication 10A, Pergamo n Press , Oxfor d (1971). * 24 . A revie w o f

th e radiosensitivit y o f th e tissue s i n bone . A reportprepare d b y a Tas k Grou p fo r ICR P Committee s I an d 2 . ICRP Publication II, Pergamo n Press , Oxfor d (1968) .

• Recommendation s o f

th e IC RP applicabl e a tth e tim e o f publicatio n o f

thi s report .P.5 5

5 0 RECOMMENDATION S O F TH E ICR P 25
. Genera l principle s o f monitorin g fo r

radiatio n protectio n o f workers
. A repor t

prepare db y aTas k

Grou p o f ICR P Committee4
. ICRPPublication 12, Pergamo n Press , Oxfor d(1969). * 26
. Radiatio n protectio n i n school s fo r pupil s u p t o th e ag e o f 1 8 years . A repor t

b y Committe e 3 o f

ICRP
. ICRP Publication 13, Pergamo n Press
. Oxfor d(1970). * 27
. Radiosensitivit y an dspatia l distributio n o f dose
. Report s prepare db y tw o Tas k Group s o f

ICR P Committe e 1
. ICRPPublication 14, Pergamo n Press , Oxfor d(1969)
. 28
. Protectio n agains t

ionizin g radiatio n fro mexterna l sources . A repor t o f ICR P Committe e 3
. ICRPPublication 15. Pergamo n Press , Oxfor d(1970). * 29
. Protectio n o f

th e patien t

i n x-ra y diagnosis
. A repor t prepare db y aTas k

Grou p o f

ICR P Committe e 3
. ICRP Publication 16, Pergamo n Press , Oxfor d(1970)
. 30
. Patien t

exposure s i n diagnosti c radiology : Protectio n problem s o f curren t concern . A statemen t

issue db y th e Internationa l Commissio n o n Radiologica l Protectio n (ICRP)
. Jul y 1973
. Br. J. Radiol., 46 , 1086-108 8 (1973)
. 31
. Protectio n o f

th e patien t

i n radionuclid e investigations
. A repor t prepare dfo r

ICR P an dadopte db y th e Commissio n i n Septembe r 1969
. ICRPPublication 17, Pergamo n Press , Oxfor d(1971)
. 32
. Th e RB E fo r

high-LE T radiation s wit h respec t t o mutagenesis
. A repor t prepare db y aTas k

Grou p o f

ICR P Committe e 1
. ICRPPublication 18, Pergamo n Press , Oxfor d(1972)
. 33
. Th e metabolis mo f

compound s o f

plutoniu man dothe r

actinides
. A repor t

prepare db y aTas k

Grou p o f

ICR P Committe e 2
. ICRPPublication 19, Pergamo n Press , Oxfor d(1972)
. 34
. Alkalin e eart h metabolis mi n adul t man . A repor t

prepare db y aTas k

Grou p o f

ICR P Committe e 2
. ICRP Publication 20, Pergamo n Press , Oxfor d(1973)
. 35
. Dat afo r

protectio n agains t

ionizin g radiatio n fro mexterna l sources : supplemen t t o ICRPPublication 15. A repor t o f ICR P Committe e 3 , ICRPPublication 21, Pergamo n Press , Oxfor d(1973). * 36
. Implication s o f

Commissio n recommendation s tha t dose s b e kep t

a s lo w a s readil y achievable
. A repor t o f ICR P Committe e 4 , ICRPPublication 22, Pergamo n Press , Oxfor d(1973). * 37
. Repor t

o f th e Tas k

Grou p o n Referenc e Man
. A repor t prepare db y aTas k

Grou p o f

Committe e 2 o f

ICRP
. ICRPPublication 23, Pergamo n Press , Oxfor d(1975)
. 38
. Radiatio n protectio n i n uraniu man dothe r mines
. A repor t

o f ICR P Committe e 4
. ICRPPublication 24, Pergamo n Press , Oxfor d(1977)
. 39
. Th e handling , storage , us e an ddisposa l o f unseale dradionuclide s i n hospital s an dmedica l researc h establish

ments
. A repor t

o f aTas k Grou p o f

ICR P Committee s 3 an d4
. ICRPPublication 25, Pergamo n Press , Oxfor d (1977). * 40
. Planne dan dunplanne drelease s o f radioactiv e material s int o th e environment
. A repor t o f ICR P Committe e 4
. (I n preparation. ) 41
. Principle s concernin g emergenc y an daccidenta l exposure s o f workers
. A repor t

o f ICR P Committe e 4
. (I n preparation. ) 42
. Radon , thoro n an d thei r daughter-products . A repor t o f aTas k Grou p o f

ICR P Committe e 2
. (I n preparation. ) 43
. Radionuclid e Deca y Schemes . A repor t .o f ICR P Committe e 2 (i n preparation)
. 44 . Problem s involve di n developin g a n inde x o f harm
. A repor t

o f aTas k Grou p o f

th e Internationa l Commissio n o n Radiologica l Protection . (I n preparation. ) 45 . Limit s forintakeo f

radionuclides . A repor t o f ICR P Committe e 2
. (I n preparation. ) 46
. Exposur e o f

ma n t o ionizin g radiatio n arisin g fro mmedica l procedures
. A n enquir y int o method s o f evaluation
. A repor t o f th e Internationa l Commission s o n Radiologica l Protectio n an do n Radiologica l Unit s an d Measurements
. Phys. Med. Biol., 2,107-15 1 (1957)
. 47
. Exposur e o f

ma n t o ionizin g radiatio n arisin g fro mmedica l procedure s wit h specia l referenc e t o radiatio n induce ddiseases : A n enquir y int o method s o f evaluation
. A repor t

o f th e Internationa l Commission s o n Radiologica l Protectio n an d o n Radiologica l Unit s an dMeasurements
. Phys. Med. Biol., 6 , 199-25 8 (1961)
. 48
. Repo n o f

th e RB E committe e t o th e Internationa l Commission s o n Radiologica l Protectio n an do n Radiologica l Unit s an dMeasurements
. Health Phys., 9 , 357-38 4 (1963)
. 49
. A revie w o f

th e physiolog y o f

th e gastrointestina l trac t i n relatio n t o radiatio n dose s fro mradioactiv e materials
. A repor t prepare db y aconsultan tt o ICR P Committe e 2
. Health Phys., 12
. 131-16 1 (1966)
. 50
. Dosimetr y o f

th e gastrointestina l tract
. A repor t prepare db y consultant s t o ICR P Committe e 2
. Heallh Phys., 12,163-172(1966)
. 51
. Depositio n an dretentio n model s fo r interna l dosimetr y o f

th e huma n respirator y tract
. A repor t prepare db y a Tas k Grou p o f

ICR P Committe e 2
. Health Phys., 12 , 173-20 7 (1966)
. Errat aan drevision s t o report , Health Phys., 13,1251(1967)
. 52
. Radiobiologica l aspect s o f th e supersoni c transport
. A repor t b y aTas k

Grou p o f

ICR P Committe e 1
. Health Phys.. 12,209-226(1966)
. 53
. Calculatio n o f

radiatio n dos e fro m proton s an dneutron s t o 40 0 MeV
. A repor t prepare db y aTas k

Grou p o f ICR P Committe e 3
. Health Phys., 12, 227-23 7 (1966)
. 54
. Radiatio n dos e fro mneutron s an dproton s i n th e energ y rang e fro m40 0 Me V t o 2 GeV
. A repor t prepare db y a Tas k Grou p o f

ICR P Committees . Health Phys., 17,449-45 7 (1969)
. 'Recommendation s o f

th e ICR P applicabl e a t

th e tim e o f

publicatio n o f

thi s report
. Accidenta l exposur e an dqualit y facto r an dremedia l acti c managemen t

o f o f publi c 24 3 Adventitiou s radiati i fro melectroni c eq Annua l limit s o f

int o us e o f weightin g I"

; calculatio n o f

1 0 Bon e radiosensitiv e cell s risk facto r fo r 4 ? weightin g facto r

f ( Bon e marro w (red ) an dleukaemi a4

- an dhaematopoiet i ris k facto r fo r 44 weightin g facto r

f c Breas t influenc e o f

ag e a n ris k facto r fo r 5 7 weightin g facto r

I c Carcinogenesi s chie f somati c ef

f e c risk factor s fo r

4

- Catarac t a s non-stochasti c e Childre n an dradiatio n dam ; Collectiv e dos e equiv
. an ddetrimen t

24 an dpopulatio n ex

p definitio n 2 2 fro mapractic e 2. ' Committe ddos e equ i an dannua l limit s o definitio n 2 6 Competen t

authorit y medica l authorit y statutor y compete n technicall y compet e Condition s o f

wor k Workin g conditio n Workin g conditio n Workin g conditio n Controllabl e source s an ddos e limitatio n Controlle dare a acces s t o 16 8 an dworkin g condi tRECOMMENDATION S O F TH E ICR P 5 1 b y aTas k

Grou p o f te e 3 o f ICRP
. ICRP

" ICR P Committe e I
. 3
. ICRPPublication

• Committe e 3
. ICRP ;temen t issue db y th e •5 , 1086-1088(1973)
. an dadopte db y th e "as k Grou p o f

ICR P Tas k Grou p o f

ICR P Committe e 2
. ICRP ZRPPublication 15. lievable
. A repor t

o f jmmitte e 2 o f

ICRP . "RPPublication 24,
a l researc h establish

jamo n Press , Oxfor d

• ICR P Committe e 4
. t P Committe e 4
. (I n e2
. (I n preparation. ) lationa l Commissio n
ethod s o f evaluation , iiologica l Unit s an d .-ferenc e t o radiatio n ial Commission s o n 6 , 199-258(1961)
. i an do n Radiologica l adioactiv e materials
. ttee2
. Health Phys., repor t prepare db y a m s t o report
. Health Committe e I
. Health b y aTas k

Grou p o f repor t prepare db y a 

### INDE X
Individua l item s i n thi s publicatio n ar e indexe db y paragrap h number
. Accidenta l exposure s an dqualit y facto r

2 1 an dremedia l action s 13 3 managemen t

o f 188-19 4 o f publi c 24 3 Adventitiou s radiatio n fro melectroni c equipmen t Annua l limit s o f

intak e us e o f weightin g factor s wit h calculatio n o f

109 22 9

10 7
•Bon e radiosensitiv e cell s o f

4 7
' risk facto r fo r 4 8 weightin g facto r

fo r 105 Bon e marro w (red ) an dleukaemi a4 4 an dhaematopoieti c cell s 45,4 6 ris k facto rfo r4 4 weightin g facto r

fo r 105 Breas t influenc e o f

ag e an dsex o n ris k

facto r ris k facto r fo r 5 7 weightin g facto r

fo r 105 3

8
Carcinogenesi s chie f somati c effec t

7 ris k factor s fo r

44-6 0 Catarac t a s non-stochasti c effec t

8 Childre n an dradiatio n damag e 6 5 Collectiv e dos e equivalen t an ddetrimen t

2 4 an dpopulatio n exposur e 131 , 132,218,21 9 definitio n 2 2 fro mapractic e 2 3 Committe ddos e equivalen t an dannua l limit s o f

intak e 10 9 definitio n 2 6 Competen t

authorit y medica l authorit y 9 3 statutor y competen t

authoritie s 13 9 technicall y competen t

perso n 16

0 Condition s o f

wor k Workin g conditio n A 161-16 6 Workin g conditio n B 161-16 6 Workin g conditio n B an dpregnanc y 11 6 Controllabl e source s an ddos e limitatio n 8 1 Controlle dare a acces s t o 16 8 an dworkin g condition s 16 3 Countermeasure s see Remedia l action s Critica l group s an ddos e limitation
. 84,21 6 an dreleas e limit s 22 5 dose-equivalen t

limit s fo r

119-125 , 21 7 optimizatio n o f

exposur e 121-12 3 variabl e characteristic s o f 85,21 4 Critica l orga n i n relatio n t o ris k

3 6 Derive dlimi t us e o f 82,147,175,17 6 Detrimen t an dcollectiv e dos e 2 4 an doperationa l optimizatio n 15 4 definitio n 1 6 Dos e equivalen t an dmodifyin g factor s 1 8 definitio n 17 , 1 8 limitatio n o f

applicabilit y 2 1 Dose-equivalen t

commitmen t an dfutur e exposure s 1 3 definitio n 2 5 us e o f 21 8 Dose-equivalen t

limi t an dsyste mo f

dos e limitatio n 11,1 2 an dstochasti c ris k

7 8 an dnon-stochasti c damag e 7 8 an dmedica l exposur e 83 , 91-9 5 an dnatura l backgroun d83 , 87-9 0 fo r worker s 96-11 6 fo r member s o f

th e publi c 117-12 8 t o preven t

non-stochasti c effect s 8 Dose-respons e relationshi p assumption s abou t

2 7 varietie s o f

2 8 Embry o see Foetu s Emergencie s see Accidenta l exposure s Environmen t releas e o f radioactivit y t o 220-22 7
Fertilit y impairmen t

o f 8,4 2 Foetu s an dmedica l exposur e 20 6 an doccupationa l exposur e irradiatio n o f

6 5 115 , 11 6P.5 7

.5 2 Gastrointestina l trac t radioseBBtivit

y o f 5 8 weightin g facto r fo r 10 5 Geneti c do « limi t recommende d formerl y 12 9 Gonad s an d cance r 4 1 an d fertSt y 4 2 an d hereditar

y effect s 4 3 risk facto r fo r 4 3 weightin g facto r 10

5 Hereditary effect s an d fomc r geneti c dos e limi t12 9 an d reproductiv e lif

e o f worker s 8 0 definitio n 6 i n immediate offsprin g 8 0 stochasti c 7 RECOMMENDATION S O F TH E ICR P

Interventio n an d abnormal situation s an d optknizatio n 15

7 level s 133,152 , 18

8 Investigatio n leve l useo f 151,177-18 1 143 , 188-194,242,24 3

Justificatio n o f exposure s 10 , 12,68,6 9 Len s an d cataract8 dose-cq«valen tlimi tfo r 6 1 opacificatio n i n 6 1 radiosensitiv e cell s in 6 2 Level s interventio n 133,152 , 188 investigatio n 151 , 177-18 1 referenc e 149.16 1 Tcaxdmg 15 0 Limit s authora d 148 , 175 , 176 , 226,227 , 23 6 basi c 34 4 derive d 147,175,17 6 secondar y 146 Linearit y see also Dose-respons e relationshi p assumptio n abou t2 7 a tlo w dose s 2 8 limitation s 3 0 Lun g an d particulate s 33 , 5 0 cance r ia : 4 9 -lymphoid tissu e i n 52-5 4 Tis k faao r fo r 5 1

- weightin g facto r fo r 10 5 Medical exposur e .an d dose-equivalen tlimit s .and noo-stochasti c effect s ;an d pregnanc

y 206 an d raSodiagnosis 19

7 an d raifiotherapy 198 an d research 203,20 4 an d takin g 20 8 83,91-9 3 93,9 5 medico-lega l an d insuranc e 20 2 optimizatio n o f

20 5 systemati c examination s 200,20 1 Medica l surveillanc e i n abnorma l situation s 18 8 o f worker s 184-18 6 Member s o f

th e publi c an d acceptabilit y o f

ris k 11 8 an d critica l group s 119-12 4 an d dos e limitatio n 8 4 an d non-stochasti c effect s 12 6 an d teachin g 23 7 dose-equivalen tlimi tfo r 119-12 6 risks t o 11 7 weightin g factor s fo r 12 5 Modifyin g factor s an d dos e equivalen t18 - Monitorin g an d occupationa l exposur e 173-18 3 an d workin g condition s 162 environmenta l 23 8 in abnorma l circumstance s 24 1 optimizatio n o f

15 6 Natura l radiatio n an d dose-equivalen tlimit s 83 , 87-9 0 an d man-mad e enhancemen t88 , 89 , 23 5 Non-specifi c effect s an d lo w dose s 6 7 Non-stochasti c effect s an d dos e limitatio n 9 5 definitio n 7 dose-equivalen tlimit s fo r 103,12 6 somati c 8 Non-unifor m irradiatio n an d dos e limitatio n 104,11 0 Occupationa l exposur e abnorma l situation s 18 8 condition s o f

work 16 1 distributio n o f

100-10 2 dose-equivalen tlimit s fo r 96-11 6 medica l surveillanc e 18 4 monitorin g o f

exposur e 17

3 risk s in saf

e industrie s 96-10 2 tota l detrimen tfro m 97-9 8 Optimizatio n an d cost-benefi tanalysi s 70-7 6 an d dose-equivalen tlimit s 7 6 an d enhance d natural radiatio n 23 6 an d safety factor s 15

9 an d technica l standard s 158,22 8 operationa l 153-15 9 Particulate s an d irradiatio n o f

lun g 33 , 5 0 Patien t protectio n o f

197-20 9 Planne d specia l exposure s dos e equivalent s permitte d 11 3 managemen to f

114,19 2 Populatio n an d dos e limitatio n 13 0 an d forme r geneti c dos e limi t12 9 exposur e o f 129- 1 Pregnanc y an d occupationa l e.

- an d radiologica l ex ; Protectiv e equipmen t an d occupationa l e

> an d planne d special Pulmonar y lymphoi d distributio n o l 52 - Quality facto r an d dos e equivalen t an d RB E 21 approximat e value s definitio n 19 limitatio n ol'applic : Rate o f dos e accumul : an d age-relate d for : an d dose-equivaler r Recordin g leve l useo f 15 0 Referenc e leve l an d conditio n o f

w i useo f 14 9 Referenc e ma n an d secondar y limi t characteristic s o f Regulation s relatio n t o !""R

P re< . Remedia l actio.i s an d intervenio n 1 an d uncontrolle d s c i n accident s 133- 1 Risk factor s an d radiatio n prote i definitio n ?A relatio n t o a •

? an d s relatio n t o hur

tan d Siever t uni tofdoseequiva l Significan tvolume s a

i an d mea n dos e 3 2 an d ski n 34 , 182 , iRECOMMENDATION S O F TH E ICR P 5 3

20 1

-12 6

3-18 3

12 6 exposur e o f 129-132,218 , 219,22 9 Pregnanc y an doccupationa l exposur e 11 6 an dradiologica l examination s 20 6 Protectiv e equipmen t an doccupationa l exposur e 167 an dplanne dspecia l exposure s 17 1 Pulmonar y lymphoi dtissu e distributio n o f

52-5 4 Qualit y facto r an ddos e equivalen t

1 8 an dRB E 2 1 approximat e value s o f

2 0 definitio n 1 9 limitatio n o f

applicabilit y 2 1 Rat e o f dos e accumulatio n an dage-relate dformul a3 5 an ddose-equivalen t

limit s 3 5 Recordin g leve l us e o f 15 0 Referenc e leve l

. an dconditio n o f

wor k 16 1 "useo f 14 9 Referenc e ma n an dsecondar y limit s 14 6 characteristic s o f

127 Regulation s relatio n t o ICR P recommendation s Remedia l action s an dinterventio n 143 , 24 2 an duncontrolle dsource s 8 1 i n accident s 133-135,19 2 Ris k factor s an dradiatio n protectio n 2 9 definitio n 2 4 relatio n t o ag e an dsex 3 8 relatio n t o hur t

an dsufferin g 3 9 Siever t uni t o f dos e equivalen t

1 8 Significan t

volume s an darea s an dmea n dos e 3 2 an d ski n 34,182,18 3 Ski n assume ddept h 6 4 dose-equivalen t

limi t 6 3 monitorin g o f

182,18 3 non-malignan t

damag e t o 8 , 6 3 Somati c effect s definitio n 6 Stochasti c effect s an ddose-equivalen t

limi t 104-11 2 definitio n 7 hereditar y 7 limitatio n o f

1 0 somati c 7 Supervise dare a acces s t o 16 8 an dworkin g condition s 16 3 Teachin g dose-equivalen t

limit s fo r

23 7 Threshol ddos e an ddose-equivalen t

limit s 1 0 an dnon-stochasti c effect s 7 Thyroi d cell s a t ris k 5 5 ris k facto r fo r 5 6 weightin g facto r

fo r 105 Tota l risk cance r 58,5 9 somati c plu s hereditar y 6 0 Trainin g an dmedica l exposur e 208 , 20 9 an doccupationa l exposur e 17 2 Vacatio n an doccupationa l exposur e 18 7 Weightin g factor s fo r dos e limitatio n 104 , 105 , 125 Whol e bod y exposur e dose-equivalen t

limi t fo r 104-112 , Wome n o f

reproductiv e capacit y an doccupationa l exposur e 11 5 an dplanne dspecia l exposure s 11 4 Workin g hour s an doccupationa l exposur e 18 7 an dteachin g 23 7 11 9

236 :2 8

### STATEMEN T FRO M TH E 197 8 STOCKHOL M MEETIN G O F TH E INTERNATIONA L COMMISSIO N O N RADIOLOGICA L PROTECTIO N Th e Internationa l Commissio n o n Radio

logica l Protectio n (ICRP ) hel dit s annua l meetin g in Stockhol min May , 1978 , togethe r wit h it s four

exper t committees
. Sixty-fiv e individual s fro mseventeen countrie s wer

e presen t

t o revie

w th e Commission' s curren t

wor k an dt o decide on aprogramm e of

wor k fo r th e next 4-yea r period
. Representative s o r observer s wer

e als o presen t

fro mth e Commissio n of th e Europea n Communities , th e Internationa l Atomi c Energ y Agency , th e Internationa l Commissio n o n Radiatio n Unit s an d Measurements , th e Internationa l Electrotechnical • Commission , th e Internationa l Radiatio n Protectio n Association , th e Internationa l Societ y o f Radiology , th e OEC D Nuclea r Energ y Agency , th e Unite dNation s Environmen t Programme , th e Unite dNation s Scientifi c Committe e o n th e Effect s of Atomi c Radiatio n an dth e Worl dHealth Organization
.

ICR P PUBLICATION 26 Th e Commissio n als o reviewe dit s 197 7 recommendation s (ICRPPublication 26) an didentifie dth e followin g point s tha t requir e clarification
. Estimates of

radiation risk Th e ris k factor s give

n by th e Commissio n i n ICRPPublication 26

(paragraph s 36-60 ) ar e base do n advic e receive dfromit s committe e on radiatio n effects
. They ar e consisten t wit h dat aavailabl e in th e scientifi c literatur e an dwit h informatio n include din th e 1977 report of th e UNSCEAR
. In th e ligh

t of it s continuin g revie

w of th e publishe dinformatio n o n th e epidemiological an dradiobiological evidenc e of

radiatio n risk s t o man , th e Commissio n ha s conclude dtha t th e informatio n availabl e u p t o Ma y 197 8 doe s no t call fo r change s i

n th e risk factor s give

n i n ICRPPublication 26. Thes e ris k factor s ar e intende dt o b e realisti c estimate s of th e effect s o f irradiatio n a t

lo w annua l dos e equivalent s (u p t o th e Commission' s recommende ddose-equivalen t limits)
. I n dealin g wit

h th e stochasti c effect s o f ionizin g radiatio n th e Commissio n recommende d(i n paragrap h 10 5 of ICRP Publication 26) weightin g factor s fo r applicatio n t o th e dos e equivalen t in variou s organ s an dtissues
. Th e Commissio n wishe s t o poin t ou t tha t i t di dno t inten dth e hand s an dforearms , th e fee

t an dankles , th e ski n an dth e len s of

th e ey e t o b e include d in th e "Remainder"
. Thes e tissue s shoul d therefor e b e exclude dfromth e computatio n o f I jw-rHj. I n orde r

t o preven t

th e occurrenc e of

non-stochasti c effects , th e Commissio n recommend s tha t th e relevan t dose-equivalent

limit s give

n i n paragrap h 10 3 shoul dappl y t o thes e tissues
. I n th e assessment

o f detrimen t

fro m exposure o

f populatio n group s asmal l ris k o f fatal cancer

resultin g fromexposure ofP.6 0

th e ski n ma

y nee dt o b e take n int o account , for exampl e i n th e cas e o f

exposur e o f

th e whol e ski n fro msof

t bet aradiation
. I n thi s cas e aris k

facto r i n th e regio n o

f IO" 4 Sv - 1 ma y b e applie dt o th e mea

n dos e ove

r th e entir e surfac e of

th e skin , whic h woul d correspon dt o avalu e of

w T o f abou t 0.01
. Th e Commission' s occupationa l dos e limit s ar e intende dt o appl y t o al l workers , an dar e base do n averag e value s o f ris k factor s for

mal e an dfemal e adults
. Th e variation s of

ris k wit h exposur e a t

differen t age s i n th e tw o sexes , referre dt o i n paragrap h 3 8 o f

ICRPPublication 26, ar e discusse din ICRPPublication 27, a report t o th e Commissio n o n "Problem s involve d i n developin g an inde x of harm"
. Thi s report als o review s th e basi s fo r th e selection , in ICRPPublication 26 (paragrap h 60 ) of

an averag e geneticall y significant fractio n (0.4 ) o f

occupationa l exposur e an dth e mea

n mortality ris k

facto r (10~ 2 Sv-' ) fo r

both sexe s an dal l ages . Effective dose equivalent Th e Commissio n recommend s tha t th e su m1T-W

T HT (se e paragrap h 10

4 o f ICRP Publication 26) b e calle dth e effectiv e dos e equivalen t (denote dH

E). Modifications to the text

of ICRP Publicatio n 2 6 Th e Commissio n believe s tha t th e followin g textua l revision s t o certai n paragraph s i n ICRPPublication 26 wil l clarif y thei r meaning
. (38 ) Th e fourth an dfift

h sentence s shoul d read : Fo r protectio n purpose s therefore , sufficient accurac y i s obtaine db y usin g asingl e effectiv e dose-equiva

lent limi t for al l worker s regardles s of ag e o r sex . Thi s limi t

i s base d upo n th e averag e risk

level s described belo w fo r th e variou s organ s o r tissues
. (79 ) Th e firs t

sentenc e shoul dread : Th e Commission' s dose-equivalen t limit s for worker s ar e intende dt o appl y t o th e su

mo f th e dos e equiva

len t resultin g fro mexterna l exposur e durin g 1 yea

r an dth e committe d dos e equivalen t

fro mtha t

year' s intak e o f radionuclides
. (79 ) Ad dth e followin g sentenc e a t th e en d of th e paragraph : Simila r principle s appl y t o th e dose

equivalen t limit s for member s of

th e public
. (89 ) I n th e secon dsentenc e th e followin g shoul db e deleted : "ar e intende da s guide s for plannin g purposes , an dthus " (93 ) I n th e firs t

sentenc e th e followin g shoul db e deleted : "ar e intende dfor

plannin g purpose s and " (107 ) Th e en dof

th e las t sentenc e shoul d read :

. . . namely , th e limi t

t o th e deep an d shallo w dose-equivalen t

indice s //j t d an dH

ltS (se e paragrap h 108) an d AL I (se e paragrap h 109)
. (108 ) Th e las t

par t ofth e firs t

sentenc e shoul d read :

. . . i t i s possibl e t o asses s th e maximum valu e of

dos e equivalen t

tha t woul doccur

a t adepth of

1 c mo r mor e in a3 0 c

mdiamete r

spher e (th e deep dose-equivalen t

index , //| >d )
. (108 ) Th e followin g sentenc e shoul db e adde dat th e en dof

th e paragraph : I n addition , th e shallo w dose-equiv

alen t inde x (th e maximu mdos e equivalen t i n th e shel l fro m0.0 7 m

m t o 1 0 m mdepth i n th e 3 0 cmsphere ) shoul db e limite dt o 50 0 mS v t o provid e i practica l th e dee p alen t in c dos e equ i t o les s th ; (110 ) Theparagr ; When e x ure s are Commis s limit s wil l followin g 

# W
an d 

### H

l. S H. sk. L where H

x equivalent shallo w d < i s th e an r

Th e firs t grou p o f intak e (ALI ) togethe r wit h th < include s th e me

t metaboli c dat a availabl e at

th e * Stockholm , an di publicatio n i n are ; fo r intake s o

f ra t Simila r informati c& M

/anou s organ s o r toul d read : :' s dose-equivalent r s ar e intende dt o o f th e dos e equiva

T external exposure n dth e committe d fromtha t

year' s elides
. entenc e a t th e en d appl y t o th e dose

- :'o r member s of

th e
;nc e th e followin g ;uide s for plannin g s " ic e th e followin g plannin g purpose s provid e protectio n for th e skin
. I n practica l situations , thes e limit s o n th e dee p an dshallo w dose-equiv

alen t indice s wil

l limi t th e annua l dos e equivalen t

i n th e len s of

th e eye t o les s tha n 30

0 mSv
. (110) Th e paragrap h shoul dread : Whe n external an dinterna l expos ure s ar e receive dtogether , th e Commission' s recommende ddos e limit s wil l no t b e exceede di

f bot h th e followin g condition s ar e met :
^E. L j 4, L an d 

### H I. s 

### H < 1 sk. L wher e H Xi i s th e annua l deep dose

equivalen t index , H

ltS i s th e annua l shallo w dose-equivalen t

index , H

EL i s th e annua l limi t

o f th e effectiv e dos e equivalen t (5 0 mSv) , H^

L i s th e annua l limi t

of dos e equivalen t i n th e ski n (500 mSv) , I. i s th e annua l intak e of radionuclid e j , AJL i s th e annua l limi t

of intak e fo r

radio

nuclid e j
. (113 ) Th e secon dsentenc e shoul d read: I n suc h circumstance s externa l exposure s an dintake s o f

radioactive material ma

y b e permitte dprovide d tha t th e sumof

th e dos e equivalen t fromth e external exposur e an dth e committe ddos e equivalen t fro mth e intak e o f radionuclide s doe s no t

'ex

cee dtwic e th e relevan t

annua l limi t in an y singl e event , and , i n alifetime , fiv e time s thi s limit
. (187 ) I n th e firs t

sentence , th e ter m"dose

equivalen t limit " shoul db e replaced b y "syste mo

f dos e limitation"
. (238 ) I n th e las t

sentenc e th e ter m"monitor

in g o f control " shoul drea d"nraomkor

in g o r control"
. t sentenc e shoul d SECONDARY LIMIT S FO RINTERNA L EXPOSUR E .nit t o th e deep an d valent indice s H

ld ragrap h 108) an d
• h 109)
. rs t sentenc e shoul d
o asses s th e maxis e equivalen t

tha t dept h of 1 c mor ameter sphere (th e .*n t index , H

ld ). Th e firs t grou p of value s o f annua l limit s of intak e (ALI ) for

radiatio n workers , togethe r wit h th e text

o f areport

tha t include s th e method s o f calculatio n an d metaboli c dat afor

22 elements , wer

e availabl e at

th e Commission' s meetin g i n Stockholm , an dar e no w in th e cours e of publicatio n in areport

t o b e entitle d"Limit s fo r intake s o

f radionuclide s by workers"
. Simila r informatio n o n additiona l element s wil l b e publishe da s soo n a s i t become s available
. Organ dos e estimate s for

member s o f

th e publi c canno t

b e derive ddirectl y fro mth e dat agive

n for worker s becaus e o f difference s i

n metabolism , orga n siz e an d duratio n o

f exposure . Th e Coeramission i s therefor e plannin g t o issu e specifi c guidanc e o n th e assessment

of interna l exposur e o

f member s of

th e public
.

tenc e shoul db e h e paragraph: tallow dose-equiv

maximu mdos e lel l fro m0.0 7 m m th e 3 0 c msphere ) I t o 50 0 mS v t oP.6 2



### CURREN T WOR

KO F ICR

P Fou r report s ar e bein g completed , preparatory t o publicatio n in th e Annals of the ICRP. Th e title s o f

th e report s are : -

—Biologica

l effect s of

inhale dradio

nuclides
. -Limit s for

intake s of

radionuclide s b

y worker s (t o replac e ICRPPublication 2).

—Radionuclid e release s int o th e environment : assessment of dose s t o man .

—Monitorin g for

interna l contaminatio n du e t o occupationa l exposure (t o replac e ICRPPublications 10an d10A). A ful l programm e of

wor k i s planne dfor th e Commissio n an dit s committee s an dtas k group s in th e immediat e future
. Subject s receivin g urgen t

review : —'" J

- * u

- following :

—Non-stochasti c effects ! -Risk s an dRBE s of

h i -Risk s t o th e human embry o an d foetus-wit h specia

l referenc e t o occupationa l exposure o f

women .

—Dose s t o patient s from radiopharmaceuticals
.

—Protectio n in al l field s in which ionizin g radiation s ar e employe din medicine
. -Th e practica l applicatio n of th e Com

mission' s recommendations
.

—Applicatio n o

f th e ICR P syste

mof dos e limitatio n t o practice s tha t modif y man' s exposure t o natura l backgroun dradia

tion
. Durin g it s ter

mof offic e th e Commissio n plan s t o prepar e revise dversion s o f it s Publication s 7 , 10 , 12 , 13 , 15/21 , 16 , 1 7 an d 24
.

for carcinogenesis :

—Somanti c an dheredil

j atio n at lo w doses
. 25PU

R A 123 1 R2In3 1 n o . 2 6 c.2 2 Intemat'l
. Comm
. o n Rad
. Prot
.

Recomm
. o f

th e Intemat'l
. Comm
. o n Rad
. Prot
. ; said Scope Founde di n 1928
. t beeir aprovidin g ge

n b y rapiddevelopmc Th e reports an dre o journal
. Annals of

h repea t a s s o o n as i t

i t i n thi s importan t

fie! Singl e issue s o f

th e j wh o d o no t

requir e cop y o f aparticul a bookseller , subscri p
Content s o

f Volum e N o E ICR P Publica ; Radiation Protectioi No
. 2 ICR P Public a The Handling. Store Hospitals ami Medic No
. 3 ICR P Public a Recommendations oj No
. 4 ICR P Public a iems Invoked

in
Forthcomin g Issue s Forthcomin g Issue s Principle s Concerni r Limit s fo r Intake s o l Planne dan dUnplar Biological EITect

s o f Radon , Thoro n an d

# final s o f th e IC R

ma n embry o an d ;ia l referenc e t o ar c o f women . patient s fro m tls
. Id s i n whic h ionizin g oye di n medicine , catio n o f th e Com

ldations
. :CR P syste mo f

dos e e s tha t modif y man' s 1 backgroun dradia

nc e th e Commissio n se d version s o f

it s 3 , 15/21 , 16 , 1 7 an d



### ad
. Prot
. at'l
. Comm

, 15PU Aim s an d Scop e

Founde di n 1928 , th e Internationa l Commissio n o n Radiologica l Protectio n ha s sinc e 195 0 bee n providin g genera l guidanc e o n th e mor e wide-sprea dus e o f radiatio n source s cause d b y rapi ddevelopment s i n th e fieldo f nuclea r energy . Th e report s an drecommendation s ofth e ICR P ar e no w availabl e i n th e for mo f ane w revie w journal , Annals ofthe ICRP. Subscriber s t o th e journa l will b e assure do f receivin g eac h ne w repor t a s soo n a s i t

appears , thu s ensurin g tha t the y ar e kep t

abreas t ofth e lates t

development s i n thi s importan t

field , andea n buil du p acomplet e se t o f ICR P report s an drecommendations
. Singl e issue s o f

th e journa l will b e availabl e separatel y fo r thos e individual s an dorganization s wh o d o no t

requir e acomplet e se t

o f al l ICR P publications , bu t woul dlik e t o hav e thei r ow n cop y o f aparticula r

repor t coverin g thei r

ow n fieldo f

interest
. Pleas e orde r

throug h you r bookseller , subscriptio n agen t or , i n cas e o f

difficulty , direc t

fro mth e publisher
. Contents o f

Volum e 1 N o 1 ICR P Publicatio n No
. 2 4 -Radiation Protection in Uranium and other Mines
No
. 2 ICR P Publicatio n No
. 2 5 The Handling, Storage, Use and Disposal of Unsealed

Radionuclides in Hospitals and

Medical Research Establishments
No
. 3 ICR P Publicatio n No
. 2 6 Recommendations ofthe International Commission on Radiological Protection
No
. 4 ICR P Publicatio n No
. 2 7 Problems Involved

in Developing an Index

of Harm
Forthcomin g Issue s Forthcomin g Issue s o f

th e Annal s wil l includ e report s o n th e followin g topics : Principle s Concernin g Emergenc y an dAccidenta l Exposure s Limit s fo r

Intake s o f

Radionuclide s b y Worker s Planne dan dUnplanne dRelease s o f Radioactiv e Material s Biologica l Effect s o f

Inhale dRadionuclide s Radon , Thoro n an dDaughte r Product s