Estimating cancer deaths from Fukushima

From: Rod Adams [mailto:rod_adams@atomicinsights.com]
Sent: Wednesday, July 18, 2012 2:06 AM
To: Higley, Kathryn A
Subject: Estimating cancer deaths from Fukushima

Dear Professor Higley:

In a July 17, 2012 CNN article titled "Researchers estimate 130 might die from Fukushima-related cancers" (http://thechart.blogs.cnn.com/2012/07/17/researchers-estimate-130-might-die-from-fukushima-related-cancers/
), your name was used in the following context:
"The methods of the study were solid, and the estimates were reasonable, although there is still uncertainty around them, said Kathryn Higley, head of Nuclear Engineering & Radiation Health Physics at Oregon State University. But given how much cancer already exists in the world, it would be very difficult to prove that anyone's cancer was caused by the incident at Fukushima Daiichi.  The World Health Organization estimates that 7.8 million people died worldwide in 2008, so 130 out of that number is quite small, says Higley."

Did your endorsement of the study methods take into account the position statement issued by the International Council on Radiation Protection (ICRP) saying that using collective dose at low exposure levels to predict health effects is not appropriate?

Specifically, from the executive summary of ICRP publication 103 - The 2007 Recommendations of the International Commission on Radiological Protection:

"(k) The collective effective dose quantity is an instrument for optimisation, for comparing radiological technologies and protection procedures, predominantly in the context of occupational exposure. Collective effective dose is not intended as a tool for epidemiological risk assessment, and it is inappropriate to use it in risk projections. The aggregation of very low individual doses over extended time periods is inappropriate, and in particular, the calculation of the number of cancer deaths based on collective effective doses from trivial individual doses should be avoided."

I appreciate your prompt response.

Rod Adams
Publisher, Atomic Insights
Host and producer, The Atomic Show Podcast


From: "Higley, Kathryn A" <Kathryn.Higley@oregonstate.edu>
Date: July 18, 2012 10:30:46 AM EDT
To: Rod Adams <rod_adams@atomicinsights.com>
Subject: RE: Estimating cancer deaths from Fukushima

Here is what I emailed CNN:

Here are some thoughts on the article

1.            The authors used some fairly standard methods to estimate where the radioactive material went, and how people were exposed and the doses that resulted.

2.            That being said – they used calculational tools, and estimated many values that had to be plugged into their computer models.   Those input values have uncertainty associated with them, and the “true” values might not be known for a while (they suggest as much in the text)

3.            Because of that, I take exception to their first statement in the abstract – namely that they are “quantifying” world-wide health effects.  I would argue instead that they are “estimating” impacts.  Yes, they are calculating numbers, but there is considerable uncertainty in them.

4.            They estimate worldwide mortality 130 deaths with a range of 15–1100, and it appears that this number is from exposure occurring over a 50 year time period (although most mortality is presumed contributed from the early months of the release).

5.            They conclude that the estimated 130 deaths are non trivial.  I do not want to minimize the pain and suffering of any individual with cancer, but the World Health Organization estimates (http://www.who.int/cancer/en/

) that in 2008 7.8 million people died of cancer world wide.  In the US alone, the American cancer society estimates that this year, 28,170 men will die of prostate cancer (http://www.cancer.org/acs/groups/content/@epidemiologysurveilance/documents/document/acspc-031941.pdf) So I take exception to the authors stating, in their conclusions that ” Fukushima nuclear accident may cause nontrivial cancer mortality and morbidity”.  There is still considerable debate in the radiobiology community if the LNT theory is valid at doses below 1 mSv, and if the response is linear, has a threshold, or is something else altogether.

6.            They do go on to compare their estimated numbers and make the final recommendation that “Nevertheless, long-term cancer risk studies should be conducted in Japan to compare with the estimates developed here as well as with future modeling studies of the health effects from Fukushima”.  I believe that the Japanese are already doing this, even though their expectation (and epidemiologists in the US as well) is that it will be very unlikely for them to detect excess cancers in the exposed population, simply due to the high background incidence of cancer.

So, there’s my two cents worth. Hope it helps.

So, in retrospect I think that my nuanced response was perhaps not the best way to respond to CNN’s inquiries.

Kathy

Kathryn A. Higley, PhD, CHP

Professor and Head
Dept. of Nuclear Engineering & Radiation Health Physics

100 Radiation Center
Oregon State University Corvallis, OR 97331-5902

541.737.0675 (w)
541.737.0480 (fax)

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