Thursday, April 29, 2010

Needles in a Haystack

Earlier this week, the National Academy of Sciences held a public meeting to discuss the Nuclear Regulatory Commission's request for a study of cancer risk in populations living near nuclear power plants. According to the NRC's announcement, the purpose of the study is to update a similar 1990 study by the National Cancer Institute. During the April 26 meeting, the NAS's Nuclear and Radiation Studies Board heard recommendations from representatives of government, industry and public interest groups. (An audio recording of the meeting is available here. A fellow blogger's summary is available here.)

NEI was among the organizations invited to address the NRSB. NEI's Senior Director, Radiation Safety and Environmental Protection, Mr. Ralph Andersen, a Certified Health Physicist, spoke on the challenges facing the NRSB. In his remarks, Mr. Andersen shared the perspective of the Health Physics Society, the association of radiation protection professionals, on epidemiological studies of this nature. The HPS says that:


"Studies of...occupationally and environmentally exposed populations...are useful in addressing allegations of adverse health effects in the population and in demonstrating a concern for the health of the exposed people. However, unless they are sufficiently powerful, they do not add to the scientific knowledge of low dose effects."
The key term is "sufficiently powerful". The HPS is referring to the statistical power needed to discern changes in the incidence of cancer.

According to the National Research Council, on average 42 out of 100 people - nearly half - will be diagnosed with cancer during their lifetime [Note 1]. With so many people contracting cancer throughout the population, the statistician's challenge is to determining when changes in that "natural background" occurrence of cancer are meaningful. As the focus of the study shrinks to smaller and smaller groups, the statistical challenge of distinguishing random variations from meaningful differences grows more difficult. When the focus is on the population around one or a handful of power plants, it becomes extremely difficult to discern meaningful differences. A very accessible description of the problem is provided at RadiationAnswers.org.

We welcome the NRC's request for this study and applaud the NRSB for taking this on. In shaping the scope and methods of its study, we hope and trust that the NRSB will heed the advice of the Health Physics Society. As we learn more about the NRSB study, we will do our part to help the public and policymakers understand the complexities of gauging the impacts of nuclear power plants on their environs.

Note 1: See Figure PS-4, page 7, in the National Research Council's 2006 report, "Health Risks from Exposure to Low Levels of Ionizing Radiation, BEIR VII Phase 2".


For a look back at some of the previous posts on concerns about cancer rates near nuclear power plants, we recommend you start with this one by Mark Flanagan and this one by David Bradish.

4 comments:

gunter said...

how about a haystack of needles...

the nuclear industry should welcome a robust health study.

After all, nobody is proposing to doing health studies around wind turbine farms.

Its radiation exposure that needs to get a clean bill of health.

Anonymous said...

Gunter, I really wonder if you even bothered to read the blog post:

[NEI welcomes] the NRC's request for this study and applaud[s] the NRSB for taking this on.

The audio webcast, however, displays you (or your namesake if you're not Paul himself) in full FUD mode. Instead of attempting to offer any relevant comments on the study, you attacked NRSB Chairman Meserve for what you percieve as bias, even after he started the session by clearly stating the board would not be doing the study nor would it decide the makeup of the experts who'd eventually do the work.

At least Makhijani and Wing made a token attempt to stick to science.

Anonymous said...

Perhaps they should....

http://cleantechnica.com/2008/08/18/wind-turbines-and-health/

But seriously. Why don't they propose a study on radiation-induced cancer around windfarms? Because it's known that they don't expose anyone to any radiation, perhaps?

Well..., the same is known for nuclear plants. The areas around plants are extensively monitored for radiation (which is extremely easy to measure), and it is known, with complete confidence, that no local residents are getting more than 0.1% of what they get from natural sources.

Meanwhile, due to variations in background, we have millions of people in certain parts of the country that get several times the average exposure, and there is no evidence of increased cancer incidence in those populations.

Based on the above, it is clear, and known, that the populations around nuclear plants are not getting any significant exposure, that could possibly cause any significant health effects. Just like those around wind farms. If any increases are seen around any plants, it is clearly due to some other agent, or a statistical fluke.

What do they hope to accomplish with this study? They seem to be just looking at statistics, and not asking if there is any agent that could possibly cause the effects in question. Bottom line is that it is known that there isn't any. Not radiation, anyway. Correlation does not prove causation.

Based on people's reactions in news reports, all this seems to be accomplishing is telling the public that scientists are still "not sure" if nuclear plants are having a health impact. Nothing could be further from the truth. Why are we continuing to study a long-settled question, whose (obvious) answer has been known for a long time?

Jim Hopf

gmax137 said...

"... all this seems to be accomplishing is telling the public that scientists are still 'not sure' if nuclear plants are having a health impact."

How true. And, by playing up this apparent 'not sure' business, the Gunters of the world killed nuclear power. Leading to countless deaths by noxious coal burning emissions.

NEI, as the public face of the nuclear industry, needs to get the facts across, and not roll over on this.