IEEJ: March 2015. All Rights Reserved.

Communicating Health Risks
from Nuclear Accidents

Gerry Thomas,Imperial College Londongerry.thomas@imperial.ac.uk

G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

The problem with radiation….
• Long history of being made to fear
radiation (from atomic weapons)• General acceptance of medical radiation
exposure, and exposure to naturalradiation (e.g. Spas) believed to bebeneficial• Relationship between dose and response
to all toxins (including radiation)• Perception that individual dose fromnuclear accidents is much higher than it is• Atomic bomb exposure very different tonuclear accident
G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

The problem with radiation risk communication
GyPBqmSv•••••

G Thomas

Too much jargon
Health effects dependon physics, chemistry
and biology
Political football
Lots of misinformationand very little
understandable science
Constant emphasis on
safety – must be unsafe

IEEJ 12/3/15

Context matters

IEEJ: March 2015. All Rights Reserved.

http://www.globalresearch.ca/new-book-concludes-chernobyl-death-toll-985-000-mostly-from-cancer/20908

http://www.newscientist.com/article/dn20403-25-years-after-chernobyl-we-dont-know-how-many-died.html

G ThomasIEEJ 12/3/15

Health effects of radiation – simple facts

IEEJ: March 2015. All Rights Reserved.

Health effects involve a combination of exposureand tissue dose (c/w health effects of sunlight)– People must have been exposed to radiation
to see a health effect– Effect depends on the radioactive isotopes
they are exposed to– Dose must be large enough to have ademonstrable effect in the numbers exposed(very small doses need very large populations
to be exposed to demonstrate an effect)
G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

Biological effect of radiation
depends on the amount of time
the radioactive isotope stays inthe body (biological half-life)
and the frequency with which
the isotope emits radiation(physical half-life)• Long physical half-life, short biological half-life – littleeffect (e.g. Cs-137)• Short physical half-life, long biological half-life – bigproblem (e.g. I-131)G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

Dose matters…..

• Annual exposure (Po-210) to average smoker• Dental X-ray• CT scan (whole body)• Radiotherapy for breast cancer• 135g of brazil nuts
• Average annual dose (UK)• Average dose to 6M residents near to
Chernobyl (over 25 years)• Transatlantic flight
G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

• Dental X-ray• 135g of brazil nuts

0.005mSv• Transatlantic flight

0.07mSv• Average annual dose (UK)

2.7mSv• CT scan (whole body)

9mSv• Av dose 6M Chernobyl residents

10 mSv• Annual exposure to average smoker 13 mSv
100mSv• Radiotherapy for breast cancer
G Thomas

50 Sv
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IEEJ: March 2015. All Rights Reserved.

Radiation releases in perspective

131-I

137-Cs

A-bomb tests in 1960s

675,000 PBq

948 PBq

Chernobyl1,760 PBq

85 PBqFukushima100-500 PBq

6-20 PBq

Sources: www.unscear.org/docs/reports/2008/11-80076_Report_2008_Annex_D.pdf
http://www.unscear.org/docs/reports/2013/13-85418_Report_2013_Annex_A.pdfG Thomas

IEEJ 12/3/15

Chernobyl vs Fukushima

IEEJ: March 2015. All Rights Reserved.

Chernobyl– evacuees mean thyroid dose 500 mGy (range 505000mGy)– Non evacuees: 100mGy– Lifetime exposure 9mSv (6M residents); 50mSv ,150,000 residents
Fukushima– evacuees estimated thyroid doses up to 80mGy,– Non evacuees estimated 45-55mGy– Actual measured doses mean 4.2 mGy– Estimated lifetime exposure 10mSv (if no remediation)
NB – lifetime exposure to background radiation approx 170mSv
G Thomas

IEEJ 12/3/15

Limiting exposure• Move population away fromsource• Limit inhalation by staying insideand keeping windows and doors
shut• Stop ingestion of contaminatedfoodstuffs• Block uptake of radionuclides(e.g. stable iodine prophylaxis)
G Thomas

IEEJ: March 2015. All Rights Reserved.

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IEEJ 12/3/15

Chernobyl – Health effects

IEEJ: March 2015. All Rights Reserved.

– 28 from ARS– 15 deaths from thyroid cancer in 25 years– 1% death rate overall predicted for thyroid cancer.
16,000 excess thyroid cancers in total predicted –therefore 160 deaths– No (scientific) evidence of increased thyroid cancer
outside 3 republics– No effect on fertility, malformations or infant mortality– No conclusion on adverse pregnancy outcomes orstill births– Heritable effects not seen and very unlikely at thesedoses– No proven increase in any other cancer (includingliquidator cohorts)
G Thomas

IEEJ 12/3/15

Fukushima Health effects

IEEJ: March 2015. All Rights Reserved.

• No radiation related deaths compared with1656 who died as a result of theevacuation or stress related to it, and20,000 in tsunami• Unlikely to be any increase in thyroid
cancer at the doses received• Psychological harm due to evacuation andradiophobia – very likely• Huge economic effect on local area andJapan as a whole
G Thomas

IEEJ 12/3/15

Health Monitoring Programme

IEEJ: March 2015. All Rights Reserved.

Fukushima Health Management Survey• ultrasonography thyroid screening of 360 000
residents below the age of 18;• comprehensive medical check-ups of 210 000
evacuees;• mental health and lifestyle survey of 210 000
evacuees;• survey of 30 000 pregnant women and nursingmothers.
Yasumura, S., M. Hosoya, S. Yamashita et al. J Epidemiol 22(5): 375-383 (2012)
G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

• Fukushima health survey will produce large
amounts of data that must be interpreted forthe public – or it will be misinterpreted by thepress and others

G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

Every cancer has aspontaneous incidence
and a natural age curve

How you lookmatters
G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

• Cancer statistics are usually reported onoperated cases• Screening finds smaller lumps, earlier• Using US will push the natural incidence curve tothe left
• Pool of undetected thyroid cancer in thescreened population estimated to be around 3
per 10,000 – some autopsy studies suggesthigher• Possibility of over treatment due to radiophobia
G Thomas

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IEEJ: March 2015. All Rights Reserved.

• UNSCEAR, WHO reports on Fukushima bothconclude that the health effects of radiation fromFukushima will be negligible• BUT the psychological effects on public healthwill be considerable• Same conclusion as the WHO report onChernobyl (published on line Feb 2011, butdated 2008)
We seem to have learnt nothing in 28 years
G Thomas

IEEJ 12/3/15

How do we get the message across?

IEEJ: March 2015. All Rights Reserved.

• Put risks from radiation into perspective withother common place risks• Take on the pseudoscientists and point out theerrors in their arguments• Correct myths put out by the media• Engage the public/media and explain
benefits/risks of all types of energy productionG ThomasIEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

Smith BMC Pubic Health 2007 7:49
G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

NB Radiation doses from nuclear accidents much lower than from A-bomb,
so risk even lower

G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

Health effects of energy production
Deaths and illness expressed as per TW (W12)/hr fordifferent sources of energy

Markandya and Wilkinson, Lancet (2007) 370: 979-90

G Thomas

IEEJ 12/3/15

Suggestions for public communication

IEEJ: March 2015. All Rights Reserved.

• Engage the media in providing facts not fiction• Engage scientists to provide an independent
voice – we need to get out more!
• Discuss openly with all sections of the community– Schools, community groups, environmental
campaigners etc• Make everyone feel part of the decision making
process – local engagement

G Thomas

IEEJ 12/3/15

IEEJ: March 2015. All Rights Reserved.

Is this response from the media justified?

Or has it just made a difficult situation worse?
Contact: report@tky.ieej.or.jp

G Thomas

IEEJ 12/3/15