Nuclear Weapons: The Final PandemicPreventing Proliferation and Achieving Abolition

New understandings of radiation effects,and new evidence from Chernobyl

Ian FairlieIndependent consultant on radiation and health

New Information New Information on Radiation Riskson Radiation Risks

Dr Ian FairlieDr Ian FairlieConsultant on Radiation in the Consultant on Radiation in the

EnvironmentEnvironmentLondonLondon

United KingdomUnited Kingdom

Radiation – a brief introRadiation – a brief intro

Untargeted Radiation Untargeted Radiation EffectsEffects

-a paradigm shift-a paradigm shift

Some Chernobyl FindingsSome Chernobyl Findings

Radiation – in a nutshellRadiation – in a nutshell

main sources main sources radiation risksradiation risks dose-response relationshipdose-response relationship politicspolitics uncertaintiesuncertainties

Main SourcesMain Sources

background radiationbackground radiation medical exposuresmedical exposures test bomb fallout from 1950s and 1960stest bomb fallout from 1950s and 1960s

Average dose UK = 2.6 mSv/aAverage dose UK = 2.6 mSv/a

Average dose US = ~3.5 mSv/a (0.35 rem)Average dose US = ~3.5 mSv/a (0.35 rem)

(1 mSv = 0.1 rem)(1 mSv = 0.1 rem)

Examples of Exposures Examples of Exposures ((mSv)mSv)mmean Effective Dose (whole-body) ean Effective Dose (whole-body)

10 mSv = 1 rem10 mSv = 1 rem

A-bomb survivors (mean dose)A-bomb survivors (mean dose) 200200

Space station - per yearSpace station - per year 170170

Radiation worker limit - per yearRadiation worker limit - per year 2020

Background radiation - per yearBackground radiation - per year 2 - 42 - 4

Public limit (EU) - per yearPublic limit (EU) - per year 11

Return flight – Boston to London Return flight – Boston to London 0.10.1

Chest X-rayChest X-ray 0.050.05

Radiation RisksRadiation Risks

1.1. difficult to determine at low levelsdifficult to determine at low levels

2.2. wide differences of view wide differences of view

3.3. major interests involved (eg military)major interests involved (eg military)

4.4. public fear of radiationpublic fear of radiation

= often much heat: less light= often much heat: less light

Feared Risks: 8 pointsFeared Risks: 8 pointsafter (Meara, 2002)after (Meara, 2002)

• invisible invisible √√• inequitably distributed inequitably distributed √√• difficult to avoid difficult to avoid √√• cause hidden or irreversible damage cause hidden or irreversible damage √√• dangerous to future generations dangerous to future generations √√• cause dread illnesses, ie cancer cause dread illnesses, ie cancer √√• difficult to explain simply difficult to explain simply √√• differing views among scientists differing views among scientists √√

√√=radiation=radiation

Risks at low dosesRisks at low doses

Dose-Response: Latest LSS DataDose-Response: Latest LSS Datasource: Brenner et al, 2003source: Brenner et al, 2003

Risks: Annual Radiation Risks: Annual Radiation Limits Limits

(1 rem = 10 mSv)(1 rem = 10 mSv)OccupationalOccupational

19341934 ~44 rem ~44 rem 19501950 ~15 rem~15 rem19661966 5 rem 5 rem19771977 5 rem + ALARA 5 rem + ALARA19901990 2 rem + ALARA 2 rem + ALARA

PublicPublic19491949 4.4 rem 4.4 rem19531953 1.5 rem 1.5 rem19541954 1.5 rem 1.5 rem19561956 0.5 rem 0.5 rem19851985 0.1 rem + exceptions 0.1 rem + exceptions19901990 0.1 rem + no exceptions 0.1 rem + no exceptions

Radiation Risks: Radiation Risks: Politics and SciencePolitics and Science

• military pressure to reduce RBE valuesmilitary pressure to reduce RBE values• U mining opposition to worker limits U mining opposition to worker limits • hormesis: radiation is good for youhormesis: radiation is good for you• Sellafield leuks: invented infective Sellafield leuks: invented infective

hypothesis?hypothesis?• denial of Alice Stewart’s studiesdenial of Alice Stewart’s studies• denial of new effects of radiationdenial of new effects of radiation• current ICRP proposals to dilute safety limits current ICRP proposals to dilute safety limits

(using background radiation as excuse)(using background radiation as excuse)

Background RadiationBackground Radiation

EXTERNAL

Primordial radionuclides in soil* 20%

Cosmic rays 17%

INTERNAL

Rn-222* , Rn-220* 50%

K-40 8%

U-238, Th-232 + progenies 4%*wide variation between countries (worldwide average given)sources: Thorne (2003); UNSCEAR (2000, annex B)

AVERAGE DOSE (WORLDWIDE) = 2.5

mSv/a

Background Radiation Background Radiation

• HPA-RP* estimated ~ 6,000 UK cancer deaths HPA-RP* estimated ~ 6,000 UK cancer deaths per year (~5% of cancer deaths)per year (~5% of cancer deaths)

• reason why women >40 years have reason why women >40 years have miscarriages/spontaneous abortionsmiscarriages/spontaneous abortions

• partly connected with ageing: why we are not partly connected with ageing: why we are not immortalimmortal

• connected)** with leukemias the reason for connected)** with leukemias the reason for long latency periods?long latency periods?

* Robb JD (1994)* Robb JD (1994)** Comare, (1986)** Comare, (1986)

Uncertainties in Uncertainties in Doses and Risks Doses and Risks

1. ENVIRO. MODELS 1. ENVIRO. MODELS - transport of nuclides- transport of nuclides2. BIOKINETIC MODELS2. BIOKINETIC MODELS - - nuclide distn’s in organsnuclide distn’s in organs3. DOSIMETRIC MODELS3. DOSIMETRIC MODELS - absorbed doses in organs - absorbed doses in organs4. 4. wwRR - for different rad’n types- for different rad’n types5. 5. wwTT - to add organ doses (Sv)- to add organ doses (Sv)6. Apply a RISK6. Apply a RISK - apply cancer risks from - apply cancer risks from

RERFRERF7. DDREF7. DDREF - for low doses/dose rates- for low doses/dose rates

= ICRP cancer risk estimate= ICRP cancer risk estimate

Uncertainties in dose Uncertainties in dose estimatesestimates

Uncertainties in Dose Uncertainties in Dose CoefficientsCoefficients

Goossens LHJ, Harper FT, Harrison JD, Hora SC, Kraan BCP, Cooke RM (1998) Probabilistic Accident Consequence Uncertainty Goossens LHJ, Harper FT, Harrison JD, Hora SC, Kraan BCP, Cooke RM (1998) Probabilistic Accident Consequence Uncertainty Analysis: Uncertainty Assessment for Internal Dosimetry: Main Report. Prepared for U.S. Nuclear Regulatory Commission, Analysis: Uncertainty Assessment for Internal Dosimetry: Main Report. Prepared for U.S. Nuclear Regulatory Commission,

Washington, DC 20555-0001, USA. And for Commission of the European Communities, DG XII and XI, B-I049 Brussels Belgium. Washington, DC 20555-0001, USA. And for Commission of the European Communities, DG XII and XI, B-I049 Brussels Belgium. NUREG/CR-6571 EUR 16773.NUREG/CR-6571 EUR 16773.

NuclidNuclidee

IntakeIntake OrganOrgan U Range U Range = (ratio = (ratio

of 95of 95thth/5/5thth percentiles) percentiles)

Cs-Cs-137137

ingestioningestion red bone red bone marrowmarrow

44

I-131 I-131 inhalatioinhalationn

thyroidthyroid 99

Sr-90 Sr-90 ingestioningestion red bone red bone marrowmarrow

240240

Pu-Pu-239239

ingestioningestion red bone red bone marrowmarrow

1,3001,300

Sr-90Sr-90 inhalatioinhalationn

lungs lungs 5,3005,300

Ce-Ce-144 144

inhalatioinhalationn

red bone red bone marrowmarrow

8,5008,500

Pu-Pu-239239

ingestioningestion bone surfacebone surface 20,00020,000

Untargeted Effects of Untargeted Effects of Radiation:Radiation:

- a paradigm shift- a paradigm shift• Hall EJ and Hei TK. (2003) Genomic instability and bystander effects. Oncogene vol 22, pp 7032-7042. “Both genomic instability and the bystander effect are phenomena, discovered relatively recently, that result in a paradigm shift in our understanding of radiation biology.”

• Baverstock K (2000) Radiation-induced genomic instability: a paradigm-breaking phenomenon and its relevance to environmentally induced cancer. Mutation Research 454 (2000) 89–109.• Belyakov OV et al (2005) Classical radiation biology, the bystander effect and paradigms: a reply. Hum Exp Toxicol 24(10):537–542. • Bridges BA (2001) Radiation and germline mutation at repeat sequences: Are we in the middle of a paradigm shift? Radiat Res 156 (5 Pt 2):631-41.• Matsumoto H, Hamada N, Takahashi A, Kobayashi Y, Ohnishi T. (2007) J Radiat Res (Tokyo). 48(2):97-106. Vanguards of paradigm shift in radiation biology: radiation-induced adaptive and bystander responses.• Morgan WF (2002) Genomic instability and bystander effects: a paradigm shift in radiation biology? Mil Med. 167(2 Suppl):44-5.• Waldren CA (2004) Classical radiation biology dogma, bystander effects and paradigm shifts. Hum Exp Toxicol. 23(2):95-100.

Untargeted EffectsUntargeted Effects

1. Genomic instability1. Genomic instability

(damage in progeny of irradiated cells)(damage in progeny of irradiated cells)

2. Bystander effects2. Bystander effects

(damage to unirradiated cells)(damage to unirradiated cells)

3.Tandem repeat [minisatellite] mutations3.Tandem repeat [minisatellite] mutations

(damage to DNA without DNA being hit)(damage to DNA without DNA being hit)

Classic ExplanationClassic Explanationfor Radiation’s Effectsfor Radiation’s Effects

Observed Effects Observed Effects of Genomic Instabilityof Genomic Instability

micronucleusmicronucleus

chromosomechromosome aberrationaberration

cell deathcell death gene gene mutationmutation

mitotic failuremitotic failure gene gene mutationmutation

gene gene mutationmutation

GenomicGenomic InstabilityInstability

• appears after 10-30 generationsappears after 10-30 generations

• induced at low dosesinduced at low doses

• induced at very high frequencyinduced at very high frequency

• in vitroin vitro and and in vivoin vivo

• mechanisms not knownmechanisms not known

• bystander mechanisms involvedbystander mechanisms involved

BystanderBystander EffectsEffects

2.Signals via gap junctions

1.Signals via medium/plasma

BystanderBystander EffectsEffects

• induced at very low dosesinduced at very low doses• induced at very high frequencyinduced at very high frequency• affects genetic and somatic cellsaffects genetic and somatic cells• in vitroin vitro and and in vivoin vivo• thought to be via chemical thought to be via chemical

signals,signals, eg cytokines or ROSeg cytokines or ROS

Observed Bystander EffectsObserved Bystander Effects

• cell proliferationcell proliferation• mutationsmutations• chromosome aberrations chromosome aberrations • changes in damage-inducible proteinschanges in damage-inducible proteins• changes in reactive oxygen specieschanges in reactive oxygen species• genomic instabilitygenomic instability • cell death (ie could be protective)cell death (ie could be protective)• in vitroin vitro and and in vivoin vivo

0

20

40

60

80

100

120

0 1 2 3 4 5 6

Dose applied (Gy)

% surviving fraction

Direct dose ICCM

Bystander effect: Bystander effect: dose responsedose responseMothersill and Seymour, 1999Mothersill and Seymour, 1999

Tandem Repeats in DNATandem Repeats in DNAeg “…AGGGTT…”eg “…AGGGTT…”

DNA Tandem Repeat DNA Tandem Repeat MutationsMutations

mini and micro satellites – non-coding DNAmini and micro satellites – non-coding DNA but increasingly thought to be functionalbut increasingly thought to be functional associated with many diseasesassociated with many diseases hypermutable: very sensitive to radiationhypermutable: very sensitive to radiation not known how mutations are causednot known how mutations are caused (ie not by direct DNA damage)(ie not by direct DNA damage) appears to be passed to future generationsappears to be passed to future generations

Untargeted effects Untargeted effects - important at low doses- important at low doses

Risk

DoseDose

Cell DeathCell DeathCellCell SurvivalSurvival

Untargeted EffectsUntargeted Effects

increased risk decreased risk

Genetic FactorsGenetic Factors

Genetic Factors

Inflammatory Responses

Untargeted Effects:Untargeted Effects: are we underestimating radiation risks are we underestimating radiation risks

at low doses?at low doses?

derive risks from classic effects at high dosesderive risks from classic effects at high dosesnew effects occur at much lower doses new effects occur at much lower doses new effects are in addition to classic effectsnew effects are in addition to classic effectstransgenerational effects?transgenerational effects?possible radiosensitive sub-populations?possible radiosensitive sub-populations?little or no dose dependencelittle or no dose dependence DDREF DDREF ≈≈ 1 not 2? 1 not 2?

Untargeted Effects:Untargeted Effects:Implications for safety?Implications for safety?

• CERRIE Committee (2004) was divided CERRIE Committee (2004) was divided • authoritative scientists (Hall, Dubrova, authoritative scientists (Hall, Dubrova,

Little, Wright, Prise etc) – state that Little, Wright, Prise etc) – state that perceived risks have increasedperceived risks have increased

• ICRP view … knowledge is ICRP view … knowledge is insufficiently developed for RP insufficiently developed for RP purposes...purposes...

• ie sanguine view, not precautionaryie sanguine view, not precautionary

Chernobyl Accident (1986)Chernobyl Accident (1986)

““..foremost nuclear catastrophe in ..foremost nuclear catastrophe in human history” human history” IAEA (1996)IAEA (1996)

““..its magnitude and scope, the size of ..its magnitude and scope, the size of the affected populations, and its long-the affected populations, and its long-term consequences make it, by far, term consequences make it, by far, the worst industrial disaster on the worst industrial disaster on record” record” IAEA/WHO (2005)IAEA/WHO (2005)

““..radioactivity released ~200 times ..radioactivity released ~200 times that from Hiroshima or Nagasaki” that from Hiroshima or Nagasaki” WHO/IPHECA (1995)WHO/IPHECA (1995)

Chernobyl FalloutChernobyl Fallout

Doses from Chernobyl FalloutDoses from Chernobyl Falloutsources: *Cardis et al, 2005; ** TORCH (2006)sources: *Cardis et al, 2005; ** TORCH (2006)

SizeSize Average DoseAverage Dose(mSv)(mSv)

Collective DoseCollective Dose(Person Sv)(Person Sv)

Liquidators*Liquidators* 240,000240,000 100100 24,00024,000

High contam areas*High contam areas* 270,000270,000 5050 13,50013,500

Evacuees in 1986*Evacuees in 1986* 116,000116,000 3333 3,8003,800

Low contam areas*Low contam areas* 5 m5 m 1010 50,00050,000

Rest of Europe**Rest of Europe** 600 m600 m ~0.4~0.4 240,000240,000

Rest of World**Rest of World** 4,000 m4,000 m ~2.5 x 10~2.5 x 10-2-2 100,000100,000

TOTALTOTAL   ~~400,000400,000 estimated deathsestimated deaths ~20,000~20,000

Chernobyl: Chernobyl: observed health effectsobserved health effects

thyroid cancerthyroid cancer

leukaemialeukaemia

solid cancersolid cancer

non-cancer effectsnon-cancer effects

minisatellite mutationsminisatellite mutations

mental health + psychosocialmental health + psychosocial

Epidemiology studies: Epidemiology studies: care requiredcare required

• differing diagnostic criteria useddiffering diagnostic criteria used• insufficient/poorly matched control groupsinsufficient/poorly matched control groups• small numbers – low statistical powersmall numbers – low statistical power• confounding factors and biasesconfounding factors and biases• nil or poor dose estimatesnil or poor dose estimates

Only use reliable studiesOnly use reliable studies

Thyroid Cancer IncidenceThyroid Cancer IncidenceJacob Jacob et alet al (2005) (2005)

Leukemias in Clean-up Workers Ivanov (1997)

CancerCancer Relative RisksRelative Risks 95% CIs95% CIs

All sitesAll sites 1.20*1.20* 1.14 – 1.271.14 – 1.27

BladderBladder 1.55*1.55* 1.21 – 1.991.21 – 1.99

ColonColon 1.31*1.31* 1.03 – 1.671.03 – 1.67

LungLung 1.28*1.28* 1.13 – 1.461.13 – 1.46

BreastBreast 2.2 (1.8)2.2 (1.8) N/AN/A

Solid CancersSolid CancersOkeanov Okeanov et alet al (2004), Pukkala et al (2006) (2004), Pukkala et al (2006)

*RRs statistically significant at 95%

Cardiovascular DiseaseCardiovascular Disease

Russian cleanup workers Russian cleanup workers ERR/Sv = 0.54 ERR/Sv = 0.54 (Ivanov (Ivanov et alet al, 2000), 2000)

(is consistent with A-Bomb studies ERR/Sv = 0.17)(is consistent with A-Bomb studies ERR/Sv = 0.17)(Pierce (Pierce et alet al, 2003), 2003)

Non-cancer effects in A-bomb Non-cancer effects in A-bomb survivorssurvivors (Preston and Pierce, 2003)(Preston and Pierce, 2003)

ERR/SvERR/Sv 95% CI95% CIss

heart diseaseheart disease 0.170.17 0.08 to 0.08 to 0.260.26

strokestroke 0.120.12 0.02 to 0.02 to 0.220.22

respiratory disease respiratory disease 0.18 0.18 0.06 to 0.06 to 0.320.32

digestive diseasedigestive disease 0.150.15 0.00 to 0.00 to 0.320.32

all statistically significant at 95% levelall statistically significant at 95% level

Transgeneration EffectsTransgeneration Effects

DNA DNA minisatellite mutation minisatellite mutation incidence doubled in Belarus and incidence doubled in Belarus and UkraineUkraine

mutations in fathers not mothersmutations in fathers not mothers

passed to their childrenpassed to their children

Dubrova et al (1996, 1997, 2002)Dubrova et al (1996, 1997, 2002)

Chernobyl: conclusionsChernobyl: conclusions

• terrible consequencesterrible consequences• health effects still occurringhealth effects still occurring• different health effects appearingdifferent health effects appearing• needs for more research + needs for more research +

fundingfunding• need to question denials by need to question denials by

many governmentsmany governments

ReferencesReferences•Brenner DJ, Doll R, Goodhead DT, Hall EJ, Land CE, Little JB, Lubing JH, Preston DL, Preston JR, Puskin JS, Ron E, Sachs RK, Samet JM, Setlow RB and Zaider M (2003) Cancer risks attributable to low doses of ionizing radiation: assessing what we really know. (2003) PNAS Nov 25, 2003, vol. 100 no. 24 13761–13766•Cardis E (2005) Cancer effects of the Chernobyl accident (presentation at IAEA/WHO Conference ‘Environmental and Health Consequences of the Chernobyl Accident’)•CERRIE (2004) Report of the Committee Examining Radiation Risks of Internal Emitters London, October 2004 www.cerrie.org (accessed February 12, 2006)•Day R, Gorin MB and Eller AW (1995) Prevalence of lens changes in Ukrainian children residing around Chernobyl Health Physics 68 632-42•Dubrova YE, Grant G, Chumak AA, Stezhka VA, Karakasian AN (2002) Elevated minisatellite mutation rate in the post-Chernobyl families from Ukraine. Am J Human Genet 71:801-809 •Dubrova YE, Nesterov VN, Krouchinsky NG, Ostapenko VA, Neumann R, Neil DL and Jeffreys AJ (1996) Human minisatellite mutation rate after the Chernobyl accident. Nature 380 683-686 •Dubrova YE, Nesterov VN, Krouchinsky NG, Ostapenko VA, Vergnaud G, Giraudeau, Buard J and Jeffreys AJ (1997) Further evidence for elevated human minisatellite mutation rate in Belarus eight years after the Chernobyl accident. Mutat. Res. 381, 267-278•European Commission (1998) Atlas of Caesium Deposition on Europe after the Chernobyl Accident. European Commission. EUR 19810 EN RU. Brussels•Goossens LHJ, Harper FT, Harrison JD, Hora SC, Kraan BCP, Cooke RM (1998) Probabilistic Accident Consequence Uncertainty Analysis: Uncertainty Assessment for Internal Dosimetry: Main Report. Prepared for U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001, USA. And for Commission of the European Communities, DG XII and XI, B-I049 Brussels Belgium. NUREG/CR-6571 EUR 16773. •IAEA/WHO (2005a) Health Effects of the Chernobyl Accident and Special Health Care Programmes. Report of the UN Chernobyl Forum Expert Group “Health” (EGH) Working draft. July 26 2005•IAEA/WHO (2005b) Environmental Consequences of the Chernobyl Accident and their Remediation. Report of the UN Chernobyl Forum Expert Group “Environment” (EGE) Working draft. August 2005•IAEA/WHO/EC (1996) One Decade After Chernobyl: Summing up the Consequences of the Accident. •Ivanov VK et al (2000) Radiation-epidemiology analysis of incidence of non-cancer diseases among the Chernobyl liquidators. Health Physics 78, 495-501•Ivanov VK, Tsyb AF, Gorsky AI, et al (1997) Thyroid cancer among "liquidators" of the Chernobyl accident. Br J Radiol 70: 937-41•Jacob P, Meckbach R, Ulanovski A, Schotola C and Pröhl G (2005) Thyroid exposure of Belarusian and Ukrainian children due to the Chernobyl accident and resulting thyroid cancer risk. GSF-Bericht 01/05, Neuherberg: GSF-Forschungszentrum mbH, 72S.; mit Anhang •Meara J (2002) Getting the Message Across: Is Communicating the Risk Worth it? J of Radiation Protection Vol 22 pp 79-85•Okeanov AE, Sosnovskaya EY, Priatkina OP (2004) A national cancer registry to assess trends after the Chernobyl accident. Swiss Med Wkly 134:645-9•Preston DL, Shimuzu Y, Pierce DA, Suyama A and Mabuchhi K (2003) Studies of mortality of Atomic Bomb survivors. Report 13: Solid Cancer and Non-cancer Disease Mortality: 1950-1997 Radiation Research 160, 381-407•Pukkala E, Poliakov S, Ryzhov A, Kesminiene A, Drozdovich V, Kovgan L, Kyyrönen P, Malakhova I V, Gulak L and Cardis E Breast cancer in Belarus and Ukraine after the Chernobyl Accident. (2006) International Journal of Cancer, in press•Robb JD (1994) Estimates of Radiation Detriment in a UK Population. NRPB Report R-260 National Radiological Protection Board, Chilton, Oxon•Thorne MC (2003) Background radiation: natural and man-made. J Radiol Prot vol 23(1) pp 29-42•UNSCEAR (2000) United Nations Scientific Committee on the Effects of Atomic Radiation Report to the General Assembly, with Scientific Annexes. (New York:UN) Annex B•US DoE (1987) Report of Interlaboratory Task Group. Health and Environmental Consequences of the Chernobyl Nuclear Power Plant Accident. US Department of Energy DOE/ER-0332 NTIS Springfield VA 22161•WHO/IPHECA (1995) Health Consequences of the Chernobyl Accident, Results of the International Programme on the Health Effects of the Chernobyl Accident (IPHECA). Summary Report. World Health Organisation.

Reading ListReading List

BooksBooks Caufield C (1990) Multiple Exposures: Chronicles of the Radiation Caufield C (1990) Multiple Exposures: Chronicles of the Radiation

Age. Penguin Books. London UKAge. Penguin Books. London UK Greene G (1999) The Woman Who Knew Too Much. University of Greene G (1999) The Woman Who Knew Too Much. University of

Michigan Press. Ann Arbor, MI, USMichigan Press. Ann Arbor, MI, US Proctor RN (1995) Cancer Wars: How Politics Shapes What We Proctor RN (1995) Cancer Wars: How Politics Shapes What We

Know and Don’t Know about Radiation. Basic Books. New York, NY, Know and Don’t Know about Radiation. Basic Books. New York, NY, USUS

ArticlesArticles Greenberg M (1991) The Evolution of Attitudes to the Human Greenberg M (1991) The Evolution of Attitudes to the Human

Hazards of Ionising Radiation and to its Investigators. Am J of Hazards of Ionising Radiation and to its Investigators. Am J of Industrial Medicine Vol 20 pp 717-721 Industrial Medicine Vol 20 pp 717-721

Rose G (1991) Environmental Health: Problems and Prospects. J of Rose G (1991) Environmental Health: Problems and Prospects. J of Royal College of Physicians of London Vol 25 No 1, pp 48-52Royal College of Physicians of London Vol 25 No 1, pp 48-52

Stewart AM (1991) Evaluation of Delayed Effects of Ionising Stewart AM (1991) Evaluation of Delayed Effects of Ionising Radiation: an Historical Perspective. Am J of Industrial Medicine Vol Radiation: an Historical Perspective. Am J of Industrial Medicine Vol 20 pp 805-81020 pp 805-810

My grateful thanks toMy grateful thanks to

Dr David SumnerDr David Sumner

Dr Keith BaverstockDr Keith Baverstock

Professor Eric WrightProfessor Eric Wright

(any errors remain the author’s (any errors remain the author’s responsibility)responsibility)