Tuesday, May 31, 2011

A Hundred Years of the Atom

As we know it, that is.

A hundred years ago today, Ernest Rutherford published a paper, “The Scattering of α and β Particles by Matter and the Structure of the Atom,” in the Philosophical Magazine. He described atoms as we visualize them today, with most of the mass concentrated in a tiny nucleus. The full story is here.

That's one of those facts that give great power to science. From that discovery came our ability to understand the structure of DNA, the development of most of today's modern medical tools, and, yes, nuclear energy in its explosive and electrical forms.

A hundred years ago, the way scientists thought about atoms was not much different from how the ancient Greeks thought about them. What a change.

Cancer Risks from Radiation

What most people want to know when they read about a reactor accident like Fukushima is how dangerous it is, particularly to themselves. The media responds poorly to the desire for that information, not without good reason.

The link between radiation and cancer risk is complex and difficult to understand, particularly for low doses of radiation, which is what most people, including reactor operators, will receive over their lives. Setting the standards for acceptable dose is a matter of judgement based on not enough data, with large uncertainties. It usually involves balancing increased dose against other circumstances, as, in Japan today, being removed from one's home.

How dangerous is radiation? Normally, forty-two people out of a hundred will develop cancer during their lifetimes. The upper ranges of low doses, more than most people's exposures, may add one more person to that.

Since the Japanese earthquake and the events at Fukushima Dai-Ichi in March, I've been trying to unscramble all this in such a way that I feel confident I understand how the numbers are derived and what they mean. For those who want to follow what I've done, here are the relevant posts:

"Exposed to Radiation"

Doses and Dose Rates

If You're Anywhere But Japan, Don't Take Potassium Iodide!

And Now...Becquerels!

Radiation Exposure Standards – Making Hard Judgements

The BEIR VII Report

Radiation Dose and Cancer Risk: Some Numbers

Limitations of BEIR VII Estimates of Radiation Risk

Increased Cancer Risks From Radiation for Workers and Children in Japan

Monday, May 30, 2011

Increased Cancer Risks From Radiation for Workers and Children in Japan

I’ve finally gotten to where I’ve wanted to be in working through BEIR VII: capable of evaluating radiation doses at Fukushima in terms of health risk. I would have liked to have been able to evaluate the radiation readings at various places around Japan in terms of health risk, but that is a few steps further still. I have a busy summer coming up, and I may not be able to get to that.

It’s too bad that it’s this difficult. For the environmental data, one must go from counts per second (becquerels) to energy absorbed (grays) to biologically effective energy absorbed (sieverts) to cancer risk via BEIR VII. That last step has been most of what I’ve done in this series. So it’s not surprising that this aspect, which is what most citizens are most interested in, is dealt with poorly by the media, which present multiples of various radiation standards, not enough to understand health risks.

From TEPCO, via the International Atomic Energy Agency, as of the end of March, twenty-one of the emergency workers had received combined internal and external doses of more than 100 mSv. Two workers had effective doses of 200-250 mSv; eight workers had effective doses of 150-200 mSv; and eleven workers had effective doses of 100-150 mSv. These range from twice the yearly allowable dose for workers to five times.

What does that mean in cancer risk? In the post before the last, I pulled some numbers from the BEIR VII tables:
The lifetime attributable risks of cancer incidence and mortality of the one-time doses, 100 mSv for protection of valuable property and 250 mSv for protection of human life, are found in Tables 12D-1 and 12D-2. If we assume that the workers are male and their age is 40, then 100 mSv gives 648 cancer cases and 337 cancer deaths per 100,000 people exposed; 250 mSv gives 1620 cancer cases and 843 cancer deaths per 100,000 people exposed.
If we compare that with the numbers of cancer deaths normally observed in the general population (42 cases per 100 people, or 42,000 per 100,000 people), that’s an increase in the probability of developing cancer of 1.5% for those exposed to 100 mSv and 3.9% for those exposed to 250 mSv.

As reported by the Federation of Electric Power Companies of Japan in their Weekly Update for May 25, 2011, the radiation level at the west gate (approximately 3,609 feet from Unit 2 reactor building) of Fukushima Daiichi Nuclear Power Station was 15.5 μSv/hour at 9:00PM on May 25. In order to accumulate a 100-mSv dose, a person would have to stay at that gate for 268 days. Note that the measurement is in micro (μ) sieverts and the dose is in milli (m) sieverts. A reading of 350-400 μSv/hour south of the main building (TEPCO) would require a little more than a day to accumulate a 100-mSv dose.

Recently, the Japanese government decided to raise the permissible radiation exposure to school children from 1 mSv per year to 20 mSv per year. Parents protested, and the government rescinded the change. The Japanese decision to raise the limit was probably based on the recommendations issued by the International Commission on Radiation Protection, which state
When the radiation source is under control contaminated areas may remain. Authorities will often implement all necessary protective measures to allow people to continue to live there rather than abandoning these areas. In this case the Commission continues to recommend choosing reference levels in the band of 1 to 20 mSv per year, with the long-term goal of reducing reference levels to 1 mSv per year (ICRP 2009b, paragraphs 48-50).
Children are more sensitive to radiation damage than adults, although the increase in sensitivity is not well known. For an adult, an increase in exposure to 20 mSv results in a fraction of a percent increased cancer risk. If we assume a tenfold increase in children’s sensitivity, which is probably high, then the children’s cancer risk increases by a few percent.

Measurements of environmental radioactivity are in becquerels per area or volume. Becquerels are indicative of the amount of a radioactive substance that is present and not simply translatable into dose received. The dose received also depends on the amount of time a person spends in a radiation zone. This is what makes evaluating the contamination in terms of cancer risk even more difficult.

It’s important to recognize that today’s measurements in Japan will decrease over time if there are no further significant releases from the reactors. The three primary isotopes accounting for the contamination are iodine-131, cesium-134, and cesium-137. Iodine-131’s half life is about eight days, so it should be approaching nondetectability in another month or so. Cesium-134’s half-life is about 2 years and cesium-137’s half-life is about 30 years, so they will http://www.blogger.com/img/blank.gifbe around longer, but their activity will decrease over time.

Setting radiation standards is an exercise of judgement. What percentage increase in cancers is acceptable? When the question is isolated like that, most people would say none. But most jobs have some hazards associated with them, even the hazard of inactivity in sitting at a desk in a clean office. The hazards of residual environmental radioactivity have to be balanced with removing people from their homes, which presents its own set of health hazards.

These are difficult decisions, made more difficult by the widespread lack of understanding of exactly what the radiation hazards are.

Cross-posted at the BMJ Blog.

What Are the Lockheed Martin Hackers Looking For?

This week brought an announcement of a very big hack: Lockheed Martin said that it had thwarted unauthorized entry to its computers by apparently the same hackers who got the secret of the RSA SecureID tokens, cards that generate random numbers in sync to authenticate users of computer systems. According to Lockheed, no harm was done because of their system security features.

That is, of course, the smart thing to say, whether it is true or not.

Emptywheel notes that other companies seem to be less willing to talk. She also notes that Lockheed Martin has its fingers in many pies, including NSA. I'll add another: Lockheed Martin runs Sandia National Laboratories, designers of the non-nuclear systems for nuclear weapons.

Friday, May 27, 2011


"Choose your enemy carefully, for you will become like him."

I've long been concerned that the United States and Soviet Union were on convergent courses. Not in everything, perhaps, but in many significant ways. Perhaps it's just the side effects of being superpowers together.

Russia has picked up some of those threads; how could it not?

Today's news had more than the usual amount of convergence.

Russia's infrastructure is falling apart. Actually, that's been true for a long time. The roads are horrible. Now it looks like the cargo boats on Russia's impressive rivers that long have served the same purposes as trains and trucks in the United States are headed in the same direction as America's bridges and highway system.

The United States has been messing around since the 1970s with an antisatellite and general-purpose flying laser system. A recent flight test supposedly was its first success, but I'm waiting to hear more. The Russians aren't, however. They're reviving their own flying laser that hasn't worked. This may be related to the discussions of missile defense, another shared delusion. Both sides think it will work. The tests suggest otherwise.

Finally, President Dmitri Medvedev is offering to try to use Russia's connections with Libya to urge Muhammar Ghadaffi to hand over the government to...someone. The article doesn't say whether Russia is offering him a dacha in Norilsk with a staff of Ukrainian nurses, however.

Thursday, May 26, 2011

Dark Skies of Denial

A line of severe storms crosses the Mississippi River in Memphis,
Tenn., passing by the Memphis Pyramid on Wednesday, May 25, 2011.
The dark formation was reported a few minutes earlier as a tornado
in West Memphis, Ark. (AP Photo/Lance Murphey)

Christy Goldfuss at The Wonk Room:
If you tuned in to the House Natural Resources Committee this morning expecting to learn about roadblocks to wind and solar development, you may have been surprised to hear yet again about how to grow the profits of Big Oil companies.

Chairman Doc Hastings’ (R-WA) Natural Resources Committee bumped today’s hearing entitled “Identifying Roadblocks to Wind and Solar Energy on Public Lands and Waters – The Wind and Solar Industry Perspective.” They replaced it with part three of their oil above all look at gas prices, including witnesses associated with the Koch brothers and Jack Abramoff...

...Another witness on the panel, Deneen Borelli, testified on behalf of the National Center for Public Policy Research, which once had Jack Abramoff on its Board of Directors. This connection is particularly of interest given that in her testimony, when discussing the need for a pro-growth energy strategy, Ms. Borelli states:
There is something terribly wrong when the corporate and social elite can use the power of government to advance their narrow interests while harming the standard of living of hardworking Americans, denying us our right to “life, liberty and the pursuit of happiness.”
Yet, she failed to recognized a recent NBC/Wall Street Journal poll that shows 74 percent of voters support eliminating tax breaks to oil companies or that according to a March 2011 survey by polling firm Greenberg Quinlan & Rosner Research (GQCR), 52 percent of voters blame oil companies for the recent increase in gas prices.

Big Oil may be the largest example of “corporate and social elite” in the world, and they continue to rely on their friends in the Grand Oil Party to protect their taxpayer subsidies and push for policies that pad their shareholder’s pockets. The votes don’t lie. The GOP controlled house has taken 13 votes that directly benefit Big Oil. Today’s postponed wind and solar hearing is just one more example of the GOP’s plan to protect oil above all, rather than get serious about reducing gas prices with a comprehensive energy plan.
Bill McKibben yesterday at the WaPo:
It’s very important to stay calm. If you got upset about any of this, you might forget how important it is not to disrupt the record profits of our fossil fuel companies. If worst ever did come to worst, it’s reassuring to remember what the U.S. Chamber of Commerce told the Environmental Protection Agency in a recent filing: that there’s no need to worry because “populations can acclimatize to warmer climates via a range of behavioral, physiological, and technological adaptations.” I’m pretty sure that’s what residents are telling themselves in Joplin today.
It is difficult, of course, to link or “attribute” individual extreme weather events in a single year to global warming. Climate factors—including human influences—shape weather patterns. According to Munich Re, one of the world’s largest reinsurers, “the only plausible explanation for the rise in weather-related catastrophes is climate change.” And as Kevin Trenberth, Sc.D., head of the Climate Analysis Section at the National Center for Atmospheric Research, explained at the American Meteorological Society’s January 2011 meeting, “Given that global warming is unequivocal, the null hypothesis should be that all weather events are affected by global warming rather than the inane statements along the lines of ‘of course we cannot attribute any particular weather event to global warming.’”

In other words, says Trenberth [his NY Times piece here], “it’s not the right question to ask if this storm or that storm is due to global warming, or is it natural variability. Nowadays, there’s always an element of both.”
But of course that's what the scientific elite with their fancy colleges and big federal government salaries would say. They're after more government funding so that they can become rich off of taxpayers money.... Or that is, at least, what George Will and other climate change denialists (or obscurantists or liars - lots more here) maintain.

Conservatives/Republicans are leading the way there, aided by well-honed techniques. Martin McKee, an epidemiologist at the London School of Hygiene and Tropical Medicine summarizes them (more here; full paper here):
I'm not suggesting there is a manual somewhere, but one can see these elements, to varying degrees, in many settings," he says (The European Journal of Public Health, vol 19, p 2). 1. Allege that there's a conspiracy. Claim that scientific consensus has arisen through collusion rather than the accumulation of evidence. 2. Use fake experts to support your story. "Denial always starts with a cadre of pseudo-experts with some credentials that create a facade of credibility," says Seth Kalichman of the University of Connecticut. 3. Cherry-pick the evidence: trumpet whatever appears to support your case and ignore or rubbish the rest. Carry on trotting out supportive evidence even after it has been discredited. 4. Create impossible standards for your opponents. Claim that the existing evidence is not good enough and demand more. If your opponent comes up with evidence you have demanded, move the goalposts. 5. Use logical fallacies. Hitler opposed smoking, so anti-smoking measures are Nazi. Deliberately misrepresent the scientific consensus and then knock down your straw man. 6. Manufacture doubt. Falsely portray scientists as so divided that basing policy on their advice would be premature. Insist "both sides" must be heard and cry censorship when "dissenting" arguments or experts are rejected.
And. it. spreads. like. a. virus.

Sunday, May 22, 2011

Barack Obama's Community Organizing

I wrote some long time ago about how Barack Obama's approach to governing appears to be based on a community-organizing strategy. But that post seems to have traveled beyond the reach of my google-fu. So I'll write something like it again, because I think it's starting to work.

Democracy depends on an informed and participatory electorate. The United States has receded from this ideal significantly in recent years, enough that numerous aspects of its governance are suffering. Congress is dysfunctional, one of the two political parties is delusional, and public discussion of these matters is abysmal.

Community organizing is about developing broad and informed participation. So it's worth a try in improving how the United States practices governance.

One of the things that voters have long found offputting is the fighting and name-calling in Washington. This is a big element of Congress's dysfunctionality and both an in-group pastime and play to extremists. It gives the talking heads and press something to talk and write about without advancing the country's interests. It leads to decreased participation by voters and, probably, the election of people who are more likely to be part of the problem, in a downward spiral.

This was only one of the problems Obama was faced with when he took office. How to end the squabbling without becoming part of it?

A great deal of advice came to him from the left that he needed to be more assertive, call out the liars, and tell them to take a walk, that he had a Democratic Congress. This would have, of course, continued the problem. If the problem is that people are fighting, you don't solve it by joining in the fight.

There are many ways to tell people that they're wrong without saying it directly or screaming at them. There are many ways to show others that people are wrong. Any skillful politician is likely to have mastered most of them, and Obama is a skillful politician. Holding power opens up possibilities in this area. One of the most important lessons of power is that you don't have to trumpet it to use it. In fact, its most effective uses are those in which it is never explicit.

There's a subsidiary strategy of taking the high ground. In an environment in which people are fighting with each other, the high ground usually requires a calm and quiet voice. The danger is that such an approach can run over into condescension and sanctimony, so there is a line to walk. Obama has found this line by allowing his opponents far more in his initial negotiating stance than they have any right to expect. His allies complain that he is giving away the store, but this has long-term effects: if he is being more than reasonable, and his opponents, say, move the goal posts or take an unyielding stand, they will eventually be seen for what they are. The alternative would be a trivialization of his position through steps that could be seen as negatively as those of his opponents.

All that would go into a smart strategy of community organizing. What I'm talking about is a discrediting of the opposition by allowing them to discredit themselves, but, in addition, quieting down the noise so that more reasonable people have time and quiet to begin thinking out reasonable positions of their own.

So the birthers raved on about long-form birth certificates, trips to Kenya, a dislike of colonialism (that's bad?), and assorted dogwhistles to racist elements, descending into self-parody. And then Obama brings out his birth certificate. The support among the hard core fell by half, almost instantly. It probably helped that Donald Trump provided much of the self-parody even before he opened his mouth, with his fluffy hairdo.

More generally, rightwing commentary lapsed into self-parody in Glenn Beck, whom even Roger Ailes recognized had gone over the top. Gold, apocalypse, and whiteboards of all the bad guys of history connected to...Barack Obama! With, of course, the more-than-occasional tear for his (sob) country. Lately aided and abetted by the prophecy, apparently for profit, that the Rapture would arrive (or depart) on May 21. Far too many words written about that, but most were, fortunately, accompanied by laughter.

John Quiggin cites a number of articles that seem to eschew the convention of "he said, she said," which the media have been roundly criticized for in the case where what "he said" is clearly a lie or insane. That tendency has corrupted the community's ability to carry on a discussion that results in rational policy by allowing lies and insanity to carry the same weight as responsible discussion. It was up to us, the citizenry, to root out this problem and shame those exacerbating it. An instant solution from the bully pulpit would have taken this opportunity to seize power from us and, in any case, was unlikely to have worked. Censorship, anyone?

But, once again, quietly and firmly, President Obama did take note of one aspect of the problem.
In June 2009, Obama gave an interview to CNBC’s John Harwood and lashed out. “I’ve got one television station that is entirely devoted to attacking my administration,” he said. “That’s a pretty big megaphone. You’d be hard-pressed, if you watched the entire day, to find a positive story about me on that front.” [link]
Obama used some of the same tactics this week with his speech last Thursday on the Middle East and North Africa. Calm, moderate, factual. The reaction was all over the map, with people still expecting that he would echo their agendas and dogwhistles. The biggest reaction was on his citing the 1967 borders as the starting point for negotiations, and the biggest objector was Prime Minister Binyamin Netanyahu of Israel, reported to have insisted, before the speech was given, that this part be deleted. After the speech, he "expected" the President to take it back. Pretty cheeky, as was his response at their joint press conference.

So Obama responded, with patient repetition of what he actually said in his speech to AIPAC today. It's people like those in AIPAC who need to be working out the US's relationship to Israel and urging Israel to do the right thing. Obama and Netanyahu get the headlines, but the community needs to determine its future. At least one commentator thinks it worked. We'll see, but it does look like some of the community organizing tactics are working.

Friday, May 20, 2011

Bits and Pieces - May 20, 2011

Two male evening grosbeaks. Body language is somewhat like the Obama-Netanyahu press conference.

Obama is playing a long game. No surprises, just steady (and often slow) movement toward the goal. That produced responses all over the map to his speech yesterday. The usual partisans were, as usual, disappointed that he didn't endorse their usual programs or provide their usual dogwhistles. I'll endorse Juan Cole's and Matt Duss's commentary on the speech and Jeffrey Goldberg's commentary on Bibi Netanyahu's reaction.

Jared Bernstein is now outside the administration and blogging. I usually don't like acronyms, but he suggests one that I'd like to see used more widely: the NASTIES (Never-A-Stinkin’-Tax-Increase-Ever!)

If Elaine Blair's review is correct, I think I understand the sentimentality of this documentary but can't sympathize with it. In 1999, I walked through Tallinn's Old Town, and it was my special place. But I also thought, on that walk, that if my Estonian friends did well, it would become something else, no longer my special place. Still special, but not in that way. I'll have to go see the move and Tallinn, too.

And here's a book about another Estonian city that's special to me. Have to pick that up, too. Should only take me a year or so to get through at my current level of fluency.

Finally, a strategy for choking off spam. If the credit-card companies would go for it.

Thursday, May 19, 2011

Two Dubious Reports on American-Israeli Nuclear Relations

There are a couple of reports out today that I would question.

Arad Exposed Secret U.S. Agreement to Jump-Start Israeli Civilian Nuclear Power Industry
Yesterday, I reported a story from Yediot that claimed Uzi Arad had given a U.S. diplomat a copy of the secret Lindenstraus report on the second Lebanon war. Turns out, there were two accurate claims in the report–that it involved the U.S. and a secret report. But the rest was wrong.

Today, a different story has been reported by [Israel's] Channel 2 about the reason for Arad’s brusque firing by Bibi Netanyahu from his senior post as national security advisor. The news report says that Arad briefed Israeli reporters and revealed that during the prime minister’s July 2010 visit to the White House, the U.S. and Israel secretly upgraded the level of their nuclear cooperation. This, according to Haaretz, followed on the heels of Obama’s surprise endorsement of a nuclear-free Middle East in which all states endorsed the NPT. This raised fears in Israel that pressure would be brought to bear against it as a non-signatory. The agreement was meant to reassure Israel. [More at link.]
Russia sabotaged Iran nuclear programme: report
Then Russian president Vladimir Putin ordered the sabotage of Iran's nuclear programme in 2006, according to WikiLeaks documents published by Israeli daily Yediot Aharonot on Thursday. The leaked documents, which were not immediately available on either the Yediot or Wikileaks websites, purportedly detail talks between the head of Israel's Atomic Energy Commission and then-US ambassador to Israel Richard Jones.

During a February 2006 meeting, Gideon Frank told Jones "at length about the results of his secret meetings with top figures in the Russian security establishment and intelligence community," Yediot reported. [More at link]
Both of these, taken together, imply a certain coziness between the United States and Israel relative to Israel's nuclear programs, which are, for the most part, weapons programs. Both of them rely on unreliable sources. I don't speak Hebrew, so I can't check the two reports linked in the first story. Silverstein's sources are unclear to me. As I read his post, it appears that Uzi Arad and possibly Yuval Steinitz, the Israeli Finance Minister are the sources. Arad has just lost his job, so what he says will be self-serving and would need to be cross-checked. Both are members of the conservative and nationalistic Likud Party.

It's hard for me to believe that the Obama administration would offer such an agreement to Israel, secretly, when the Bush administration's open agreement with India has caused so much trouble. Or reassuring Israel that their nukes are all right with the US when there's been so much nuke-rattling in Israel against Iran? In addition, relations between Israel and the United States have been cool lately. Israeli Prime Minister Binyamin Netanyahu was invited to address Congress by members of Congress. Could such an agreement have been used as a bargaining chip? Seems like a long shot to me.

In the second story, there is a long chain: In February 2006, the head of Israel's Atomic Energy Commission, Gideon Frank, tells then-US ambassador to Israel Richard Jones about his conversations with Sergei Ivanov, foreign minister Sergei Lavrov and the chairman of the Russian Atomic Energy Commission, Sergei Kiriyenko. Apparently it was in these conversations that it was claimed that "Putin had personally ordered measures to delay progress at Iran's Bushehr nuclear plant." So the report assumes that every link in the chain had no reason to fabricate or exaggerate. This report is somewhat more plausible on its face than the first, but that long chain is like the chain in many other Wikileaked diplomatic cables. It's a report home by the ambassador on what he's heard. That's useful information to the State Department whether it's true or not; certainly not a confirmation that it's true.

Another connection that might be drawn is with today's speech by President Obama on the Arab uprisings and the upcoming visit by Prime Minister Netanyahu. An attempt at a show of strength by Likud? To discredit Obama? Or just coincidence?

Bits and Pieces - May 19, 2011

Remember how Senator Jon Kyl (R-AZ) held the New Start Treaty hostage to assurances of funding for the nuclear weapons enterprise? The House Republicans are undercutting that funding.

An analysis of the likely successor to Osama bin Laden.

Christopher Hitchens on the framing of American and French attitudes toward sexuality in their leaders.

Added later: Can't be said too many times in too many ways. More graphics showing that the Bush tax cuts are a big factor in the deficit.

Wednesday, May 18, 2011

Activity at Fukushima

There's been an impressive amount of work done at Fukushima, cleaning up the debris from the tsunami and getting in the equipment needed to deal with the reactors and the spent fuel pools.

As you watch the video, just think about what it takes to move stuff around, get it in the right place, get it hooked up, all in that protective clothing you see the workers wearing. And the videographer is probably wearing it too.


Tuesday, May 17, 2011

Limitations of BEIR VII Estimates of Radiation Risk

While I do love numbers, it’s important to understand their limitations. Numbers are essential for verifying predictions, but the limitations tell you how much you can rely on the numbers I gave in my previous post.

The biggest limitation of BEIR VII, or any other study of radiation effects, is the lack of data. The BEIR VII authors, after analyzing a large number of studies of various populations, conclude that the only studies that meet all their criteria are those of the Japanese atom-bomb survivors. And even those are not perfect: dose was not measured directly, but reconstructed as a function of distance from the blasts. And it’s a one-time dose, not continuing.

Other studies give slightly different results, but they have other problems. Studies of workers who may be exposed to radiation show lower cancer incidence; Chernobyl exposures seem to have resulted in much larger numbers of thyroid cancer than other exposures have. Doses are very well known for the radiation workers, less so for those exposed to Chernobyl fallout. Health studies of workers find that people who are working tend to be in better health than the general population, which may explain the lower incidence. The areas around Chernobyl are known to have a high incidence of goiter, indicating iodine deficiency, which could result in increased iodine-131 uptake and higher cancer incidence.

Probably the biggest limitation is not enough numbers of exposed people to investigate reliably the small increases in cancer that small exposures to radiation may cause. So the BEIR VII numbers have large associated uncertainties, and uncertainty in what the uncertainties might be.
Because of the various sources of uncertainty it is important to regard specific estimates of LAR with a healthy skepticism, placing more faith in a range of possible values. Although a confidence interval is the usual statistical device for doing so, the approach here also accounts for uncertainties external to the data, treating subjective probability distributions for these uncertainties as if they resulted from real data. The resulting range of plausible values for lifetime risk is consequently labeled a “subjective confidence interval” to emphasize its dependence on opinions in addition to direct numerical observation. [page 278]
LAR is “lifetime attributable risk,” the additional risk incurred by radiation exposure.

So, restating the numbers from my previous post on this subject,
For the public limit, the BEIR VII committee’s preferred estimate is in Table 12-6. 1 mSv per year throughout life, the expectation is that there will be 550 cases of cancer and 290 deaths per 100,000 males, 970 cases and 460 deaths per 100,000 females due to this incremental radiation exposure.
in terms of confidence limits gives

280 to 1100 cases of cancer and 140 to 580 deaths per 100,000 males and
510 to 1840 cases of cancer and 230 to 920 deaths per 100,000 females.

The committee has chosen the numbers it thinks are best justified, but the actual numbers might be twice or one-half those numbers. The committee’s estimates are the best we’ve got, but those ranges need to be kept in mind.

It’s important, as well, to put those cancer cases in context. BEIR VII does this in the Public Summary’s Figure PS-4.
In a lifetime, approximately 42 (solid circles) of 100 people will be diagnosed with cancer (calculated from Table 12-4 of this report). Calculations in this report suggest that approximately one cancer (star) per 100 people could result from a single exposure to 0.1 Sv of low-LET radiation above background.
That’s 100 milliSv, twice the yearly allowable dose for radiation workers.

The assumption in BEIR VII that radiation affects health in a linear way down to low doses has been criticized from both sides as giving too high and too low an estimate. The committee’s response is that the experimental evidence seems to be most supportive of the linear assumption [pages 8-9]

I came to BEIR VII fairly skeptical. It has seemed to me that the human body has evolved in a mildly radioactive world, more radioactive at earlier times than later, and that it must have evolved ways to deal with that radioactivity. Many chemical compounds and elements are necessary for life but toxic at higher concentrations; iron is only one example. Might it be the same for radiation?

Working through the report carefully has convinced me that it is the best information we have available. That is not the same as being precisely correct in all aspects. There are many holes in the data and in our understanding of the steps from cell damage to cancer. It is possible that some of the findings in BEIR VII will be overturned as our knowledge in these areas increases.

But that is how science is done: the best understanding is woven out of the available data and used in further investigation, the results of which are woven back into that understanding.

Cross-posted at BMJ Blog.

Bits and Pieces - May 17, 2011

Now that the Armchair Generalist has gone silent, I guess it's up to me to note some of these milestones. Last of bulk mustard gas at Deseret Chemical Depot in Utah has been destroyed. More info here.

Bernard-Henri Levy predictably defends his friend Domenique Strauss-Kahn in terms of that privilege I've been talking about. (Via Kevin Drum)

And speaking of privilege, it's hard to believe that there weren't other qualified people for the post of State Department spokesperson.

Speaking of framing a narrative, as I was yesterday, here's what happens to embedded reporters.

And then there's simple plagiarism. You probably haven't seen it in the MSM, but one of the attackers of the "hockey stick" curve who helped Congressional enemies of climate science has been found guilty of it. John Quiggin starts sort of in the middle, but he has links to help out, and I think his is the best summary so far of what's happening. John Cole's pithy comment is good, too. More from Ivan Oransky.

The US Nuclear Regulatory Commission is ending its emergency watch on Fukushima because the reactors are stabilizing.

Need a cool poster detailing a nuclear reactor? Get yours here.

Physicists have enjoyed applying their humor to naming things. That hasn't been working out so well for the nuclear industry.

A really good interview with Gary Samore, President Obama's point man on arms control.

And if you have made it this far, you are rewarded with a slide show of the Bempton Cliffs gannet colony!

Monday, May 16, 2011

Bits and Pieces - May 16, 2011

The fox is getting to be a regular visitor, eating birdseed here just after I've put it out for the doves.

More on Domenique Strauss-Kahn: Steve Clemons bemoans the loss of his thinking. I'm wondering if there are no such thinkers around who don't feel the need to force women into sex acts. Or even if there are such thinkers who are women. Meanwhile, Counterpunch spins what the same facts Steve provides into a conspiracy theory. Via Jamie, who finds that ridiculous, although I'd refer him to my post on the subject for why. Is anyone besides me getting tired of conspiracy theories?

Have we reached peak wingnut?

Zenpundit asks some interesting questions on how the clandestine services will be able to operate in a Facebooked, Wikileaked world.

A. Q. Khan, father of Pakistan's (and probably others') nuclear program, speaks. Sounds remarkably like the justifications given for ever-increasing numbers of nuclear weapons during the Cold War.

Sanctions seem to be working on Iran's nuclear program. I'm wondering if the difficulties imposed by the sanctions are part of what is causing strife among Iran's rulers.

Fukushima and Epistemology

TEPCO is releasing more and more information about Fukushima. And it's not all getting into the news. I'm on a listserv that sees a bit more than the media makes available. I'm not going to go into the details in this post, though. Rather, I'd like to consider how we know what we think we know about Fukushima and how much it matters.

Last week we had an, er, meltdown in some quarters over the news that the core of reactor #1 seems to be more damaged than previously thought. The increase was from 70% damaged to 100% damaged, which hardly seems to me worth some of the breast-beating over MELTDOWN!

That word has been used since the beginning of the crisis. Early on, most of the users seemed to have "The China Syndrome" in mind: a molten blob eats its way through the reactor vessel, concrete foundation, and keeps going under its own fission power to emerge in China, or wherever is the antipode of the reactor's original location.

I've kept to words like "damaged fuel," which can include melted fuel. It would take extremely high temperatures, higher than have been reported for the Fukushima reactors, to produce a molten blob. What seems to have happened, according to the latest reports, is that the fuel element cladding warped, split, and perhaps melted, which allowed the fuel pellets, each about as big as the tip of your thumb, to pour out of the fuel elements and settle to the bottom of the reactor vessel.

Large industrial machinery is set up to keep people away. It's hot or pressurized or radioactive or has moving parts that easily crush flesh and bone. So that humans can keep track of what it's doing, sensors for quantities like temperature and pressure are attached to meters or computer control systems, which the humans can use to modify what the machinery is doing. This is true of any power plant - gas, coal, or water-powered - and most manufacturing. When something goes wrong, the sensors may fail. This is why nuclear reactors have multiple levels of containment, at Fukushima, the inner two a thick steel pressure vessel and an outer concrete structure, to contain the radioactive materials if the worst happens.

If the sensors fail, there may be indirect ways of measuring what is happening. Temperature measurements of the outside of the concrete structure provide limits on what the interior temperatures may be. Rising pressure indicates steam production from something hot inside.

Then there is the question of who knows what. At the plant, the operators have pieces of information that need to be coordinated. This is usually done through the control panel, but an emergency means that there will be problems with the control panel. Someone will have to make decisions on what measurements are needed and what actions to take. Many of those actions are dictated by emergency plans; some may have to go outside them. In the executive offices, people are coordinating with government officials and deciding what to say to the public. Everyone needs information, but the further you get from the reactor, fewer details are needed.

I'm far, far down the line of people who need information. I'm not anywhere where Fukushima's radiation will affect me. I can't do anything to help or hinder. Maybe send some money to help the evacuees. But all I need to know to do that is that there are evacuees. As a blogger, of course, I'd like to have a direct line to TEPCO and have all my questions answered instantly.

So why the clamor every time something new appears? Was TEPCO lying in earlier estimates of reactor damage? Or have they learned something new? Why is it a big deal to go from 70% damage to 100% damage? And why the focus on "meltdown" and "re-criticality"?

I'm going to suggest that, in the absence of a detailed understanding of how things go wrong in nuclear reactors, there's a very attractive narrative line that's been furnished by "The China Syndrome." Any number of easy rebuttals have been provided; I think the movie doesn't even say that the molten mass (see how familiar those phrases become) will emerge in China. Gravity would, of course, stop it at the center of the earth, if something else, like the pressure vessel didn't stop it first.

For this narrative line, we need a molten mass, presumably from the meltdown, and we need a continuing state of nuclear criticality. So it's very important that there be a meltdown and that criticality be re-established. I suspect that the commentators who are so focused on "meltdown" and "re-criticality" don't even realize that a movie's narrative line is driving their reasoning, but I don't see another reason that these terms have taken on such importance.

A meltdown could seriously breach the reactor containment, and if it did so, the radioactive reactor contents could be distributed widely, as at Chernobyl. The question that one would focus on, however, if this were the concern, would be whether there is a reactor breach. The fact that the containment vessels hold some pressure indicates that they haven't been breached Chernobyl-style. We'd also be seeing a much greater variety of fission products and actinides if there were a big breach, particularly in conjunction with a meltdown. (Added later: A blog post isn't a scientific paper, but I think I should add that I do think there's a breach in the coolant system. More below.) With all that water around, we'd be seeing steam explosions. But the media and other focus is on meltdown.

The furor over "re-criticality" has subsided somewhat, but it's not gone. The heat from continuing fission is what would drive the molten mass through the steel and concrete containments. So "re-criticality" is essential to that narrative line. I've written before why it's unlikely. That post might be updated a little. I'm recalling from my time in a reactor design group that new reactor designs had to have a calculation in which all the fuel was on the bottom of the vessel, and it had to be less than a critical mass. I think they still have to do calculations like that in order to get reactor designs certified.

TEPCO has concealed information and lied in the past. For both the corporation and the Japanese government, there is an issue of losing face, which may lead to concealment. For TEPCO in particular, there are likely to be heavy financial penalties. The government is considering putting TEPCO into receivership and taking its money to compensate the evacuees. So the last few days' reports of possible earthquake damage before the tsunami would take some of the responsibility off TEPCO employees and perhaps argue against fault on TEPCO's part. There are many possible motives for the release of various sorts of information.

TEPCO is making more and more information available. I saw the curves of pressures in the reactors after the earthquake this morning. Not simple to interpret, so I won't try just now.

Whether it's the state of the cores and the fuel elements in the cooling ponds or TEPCO's culpability and information flow, we're not going to have definitive evidence for months or even years. So, as I've said before, I'm trying to get past the hooting and hollering every time another number is released. Or every time the MSM finally figures out something to say about it. By and large, the worst of the crisis is over. It will take some time before all the reactors are in cold shutdown, and surprises are always possible. But last week's release of information wasn't among them.

Added later: There is probably a breach in the primary coolant systems at reactor #1, and probably at others. The coolant system consists of piping and pumps, somewhat like the hot water system in your house. The weak points are where pipes are connected to pumps and to the containment vessels: fittings and seals. The earthquake could have broken these connections, or too much heat could have. But the fact that the only fission products we're seeing are the soluble ones argues that they're coming out with the water.

Sunday, May 15, 2011

Food Loss and Waste

The publication announcement of this FAO report on global food waste and loss skirted the news a few days ago.
Roughly one third of the food produced in the world for human consumption every year — approximately 1.3 billion tonnes — gets lost or wasted, according to an FAO-commissioned study.

The document, Global Food Losses and Food Waste [.pdf], was commissioned by FAO from the Swedish Institute for Food and Biotechnology (SIK) for Save Food!, an international congress being held in Düsseldorf 16-17 May at the trade fair of the international packaging industry Interpack2011.

Other key findings include:
  • Industrialized and developing countries dissipate roughly the same quantities of food — respectively 670 and 630 million tonnes.
  • Every year, consumers in rich countries waste almost as much food (222 million tonnes) as the entire net food production of sub-Saharan Africa (230 million tonnes).
  • Fruits and vegetables, plus roots and tubers have the highest wastage rates of any food.
  • The amount of food lost or wasted every year is equivalent to more than half of the world's annual cereals crop (2.3 billion tonnes in 2009/2010)...
The report distinguishes between food loss and food waste. Food losses — occurring at the production, harvest, post-harvest and processing phases — are most important in developing countries, due to poor infrastructure, low levels of technology and low investment in the food production systems.

Food waste is more a problem in industrialized countries, most often caused by both retailers and consumers throwing perfectly edible foodstuffs into the trash. Per capita waste by consumers is between 95-115 kg a year in Europe and North America, while consumers in sub-Saharan Africa and South and Southeast Asia each throw away only 6-11 kg a year.

Total per capita food production for human consumption is about 900 kg a year in rich countries, almost twice the 460 kg a year produced in the poorest regions. In developing countries 40 percent of losses occur at post-harvest and processing levels while in industrialized countries more than 40 percent of losses happen at retail and consumer levels.

Food losses during harvest and in storage translate into lost income for small farmers and into higher prices for poor consumers, the report noted. Reducing losses could therefore have an "immediate and significant" impact on their livelihoods and food security.

"The Corpse Will Be Taken to Tonga"

From Futility Closet:
Useless phrases drawn from actual phrasebooks by Swedish linguist Mikael Parkvall, from Limits of Language, 2006:
  • At what time were these branches eaten by the rhinoceros?
  • I don’t play the violin, but I love cheese.
  • I have my own syringe.
  • I had a suckling-brother, who died at the most tender age.
  • The beast had a human body, the feet of a buck, and a horn on its head.
  • Because I was out buying a pair of wooden shoes.
  • I had yams and fish for two days, and then I ate fern roots.
  • I want a specimen of your urine.
  • The corpse will be taken to Tonga.

Privilege and Elites

Early yesterday, Zenpundit tweeted an article by Walter Russell Mead on the corruption of the elites. Later yesterday, yet another example of that corruption hit the headlines.

There are a number of things I think are wrong about the Mead article, not least, as Pundita notes, that Mead himself is a member of that elite establishment. And I should include the mandatory disclaimer that Dominique Strauss-Kahn is innocent until proven guilty.

I'm not in total agreement with the Paul Krugman article that Mead links, either. I'm following the idea that power corrupts and that elites will use that power to maintain and cover up that corruption. Further, that this is a large problem across the world, including America.

The two elites that come together in the person of Strauss-Kahn and the crime he is accused of are the world-ruling elite of the President of the International Monetary Fund, hopeful of running for President of France, and the male elite. The response of far too many male commentators has been revealing. On a listserv I participate in, a male commentator says that this "smells of entrapment." As so many male commentators have said of so many sex crimes for so many years. In the link I've provided above, Christopher Dickey seems unable to distinguish between "skirt-chasing" and sexual assault. And why not? Skirt-chasing has been a privilege of males, particularly as they acquire money, and it's slopped over into sexual assault like forever. Part of that male elite privilege.

So my less moneyed male friend on the listserv feels sympathy for this poor entrapped male, never mind that that same male privilege makes it very unlikely that a maid at a hotel would irritate the (largely male) management with such a claim. At the same time, this same friend complains loudly about other misuses of power by ruling elites. That's not too different from the Tea Party's support of not taxing the rich while complaining about poor governance.

It's the overlapping of those elites, and the elites we don't see, that help to perpetuate that misused power. That's why it was so smart for Mead, as a member of those elites, to hide in plain sight by condemning their corruption.

Update: From another old friend, Jamie K, who is better than I am at literary subtlety.

Wednesday, May 11, 2011

How Perpetual War Became US Ideology

I think that James Joyner is right, if we're talking about ideology. He points out the commonalities and alliances between liberal interventionists like Samantha Power and Hillary Clinton and neoconservatives like Bill Kristol and Robert Kagan

I'd like to add a couple of things on the practical side. Americans love technology. So it's easy, too easy, to believe that we'll put our high-tech begoggled and battery-using military on the ground, and they'll fix it all. After all, they're our kids, nice guys who will be happy to have a cup of tea with the tribal leaders. And if that doesn't work, we'll send in those carefully targeted missiles. No sweat.

We love technology, which we use to assure ourselves that no old ladies or babies will set their underwear on fire trying to bring down the plane we're taking to visit Disneyland. We love technology, except when we're scared of it and take potassium iodide in San Francisco to counteract the radioiodine in Japan. But the potassium iodide is technology, too, we like to believe good technology. And just look at those new internet-enabled cars! And if we buy a hybrid that gets more mileage to the gallon, then we can buy an immense SUV, even if it's fewer miles to the gallon than a smaller gasoline-engined car.

The American public loves a quick fix, and if it's by technology, it's a sure sell.

The military, of course, embodies that quick technological fix, and the federal budgets have aided and abetted the image and the reality. Even Robert Gates, the Secretary of Defense, has suggested that some of his Department of Defense budget might be diverted to the State Department. But Congress loves those gizmos, too, especially when they're manufactured in their districts. And State manufactures many fewer gizmos.

Joyner's article is a good jumping-off place to start rethinking our foreign policy. I feel like we still haven't gotten away from the anxiety-ridden tropes of the Cold War, now two decades past.
The passionate zeal of the liberal interventionists and neoconservatives satisfies an emotional hunger that has been a part of our political system since the emotion-laden days of the Cold War, when the public first came to view U.S. foreign policy as a tool of good to be deployed against evil.
The Soviet Union was evil (didn't Ronald Reagan say so?) and the US is good. So we're still good, right? And so we can make all those other nations' stories come out with a happy ending, right? Right?

Update: Another good article, on a very different subject, as a basis for rethinking some of our problems.

Annals of Egregious Science Reporting

I mentioned the alignment of planets in the morning sky a week or so ago. Now comes Jeffrey Kluger of Time Magazine to enlighten us. I can't help but think that he wrote this completely at his computer, never bothered to look out the window. Or at any sort of astronomical background, like a diagram of planetary orbits.

But first, a disclaimer from someone who has been looking out her east window in the morning. This arrangement is not as impressive as it has been made to seem, especially if you have mountains rising toward the east. The planets rise only a half-hour or so before the sun, and, for me, the mountains allow for the sky to lighten quite a bit before the planets get over them. So this has not been too impressive, even with binoculars. Maybe I'll get my telescope out tomorrow, but what I've seen so far does not inspire me to dig in the closet.

Kluger (is that really his name?) affects that breezy, humorous tone so necessary for a reporter who doesn't know what he's talking about. So I'll skip the first few paragraphs.
Beginning today and lasting for a few weeks, Mercury, Venus, Jupiter and Mars will be visible in the early morning sky, aligned roughly along the ecliptic — or the path the sun travels throughout the day. Uranus and Neptune, much fainter but there all the same, should be visible through binoculars.
Um, the reason I posted last week is that all this "began" some time ago. At the origin of the solar system several billion years ago, perhaps, or last week for the closing paths of the planets. Today they are all clustered most closely. Nothing about the view of the planets from Earth takes place quickly.
What's more, even this month's apparent planetary lineup is as much illusion as fact. In the same way a group of people scattered randomly across the room can appear to be aligned depending on your angle of sight, so too can planets that seem tidily arranged from one point of view turn out to be nothing of the kind when you look at them another way.
What he's trying to say here might have been helped by a diagram of where the planets are, and where we're looking at them from. Kluger assures us, on NASA's word, that this does not mean the end of the world or anything in particular, and then goes on:
That's not to say there aren't truly meaningful planetary alignments. Indeed, there was a whopper of one in the late 1970s, which was accurately forecast by an engineer named Jim Burke at NASA's Jet Propulsion Laboratory in 1966. Burke used no sorcery to make his prediction, but rather the hard science of orbital mechanics — calculating the speed and position of all of the planets, projecting forward, and discovering that Jupiter, Saturn, Uranus and Neptune were just 13 years away from forming a once-every-176-years conga line.
Burke must be a drinking buddy of Kluger's. This sort of calculation is done regularly by the people who prepare ephemerides - the tables of planetary motion, which now are available to everyone through software.

Too bad Time couldn't find a reporter on staff who could learn any of this.

Tuesday, May 10, 2011

Just a Cute Photo

of my fox, little pink tongue and all.

Monday, May 09, 2011

Bits and Pieces - May 9, 2011

A few good pieces on Osama bin Laden finally appearing. (That means they more or less agree with my views, I guess.)

There won't be another bin Laden.

Gilles Kepel: Opportunity for Obama

Bottom line in the torture debate: We cannot become our enemy in trying to defeat him. Thanks, Matthew Alexander!

Also a bunch of nuke stuff.

This article doesn't make sense to me. The author obviously doesn't know what red oil (indeed dangerous, and real, unlike red mercury) is or how it's formed and so doesn't realize that safety in regard to it is an operational matter: how often the solvent is refreshed. The reported reactions of a couple of experts suggest to me that the safety issue goes deeper than this, but the reporter didn't probe that. Or else was making a mountain out of a molehill.

The Russians don't seem to be directly involved in the preparations for startup at Bushehr. They have seemed to be concerned about the safety of the plant.

Pavel Podvig on nuclear fuel banks. I haven't read this yet, but Podvig is usually good.

Long article in the Atlantic on a trip to the Nevada Test Site. Global Zero asked earlier today, via Twitter, whether we can "unlearn the bomb." Perhaps in a metaphorical way we can, but relative to the discussion in this article, the answer is no: what Steve Younger is talking about is a high degree of refinement that the weapons designers at Los Alamos and other places reached. If you just want a big radioactive boom, the Manhattan Project's Little Boy proved that's not extraordinarily hard if you've got lots of money and facilities. The linked photo and video shows are good, if you like nuke porn.

Finally, Felix Salmon wrote a piece last Friday on the New York Times's odd linking practices: they link only to themselves, as the Lodges and Cabots reserved their conversations. Here's one small piece of what's wrong with that. And just how trivial some of the Times's concerns can be.

Sunday, May 08, 2011

Texan Priorities

The Texas House Ways and Means Committee has approved a tax break for those who want to buy yachts costing $250,000 or more.

In a vote late Thursday, the committee approved a bill by Houston Republican Rep. John Davis. The proposed law would cap the maximum sales tax the state would collect on the sale of a personal boat.

Davis says the measure is needed because Florida has a similar law and boat buyers are going there to make their purchases. The measure passed on an 8-3 vote along party lines.
Because it's so obviously in the name of the public good.

Phytocrene Bracteata

Friday, May 06, 2011

Squabbling About Legalisms

It seems to me that the commentary about the precise status of Osama bin Laden's death - legal or not, act of war or not - is missing some points.

The action of the SEALs within the Abbotabad compound is not the main point. They were sent on a mission into hostile territory that likely would be defended to the death. So the orders they should have been given would have been to use deadly force as necessary. Anything else would have jeopardized the mission and the lives of the SEALs. The alternative would have been not to do the mission. So it is those who planned the mission and issued the orders who are at fault, if that is the case. This may be the criticism intended by a number of commentators, but the frequent use of details (like how bin Laden was shot) obscures this point.

Think it out: the SEALs rappel from helicopters into the courtyard, and they're going to hold up their IDs and say they've got a warrant? They're going to march into the house peacefully and ask bin Laden if he would like to surrender?

A number of people, the latest here, have opined that the mission was fully legal. I tend to agree with them, and, if the papers were not fully in order, I'm willing to be one of those who make an exception to strict legality for bin Laden.

The way the news was released by the administration does allow for multiple interpretations, but they mostly have to do with those operational details that obscure the main point. If the administration had waited until everything was perfectly clear, which would have taken another day or more, very likely the same people raising a fuss about multiple stories in a coverup now would have complained about taking time to set up a single story as a coverup. I'm in favor of the transparency of the immediate, even if that results in having to correct errors.

I find a couple of things disturbing about this sort of commentary. First, the sense that the commenters could have done a much better job, legally or operationally. This speaks to me of people who have never done a complicated operation in the real world, where confusion and ambiguity reign. Nor have they taken the time to understand how real operations work. I'm not just talking about carefully considering Clausewitz's fog of war; I'm talking about the environmental cleanups I've done, or perhaps organizing a field trip for their child's class. With some imagination, one may extrapolate to a situation in which armed people who don't want to be found respond to other armed people who appear suddenly.

Second, the loss of the ability to believe our government. This started long ago, and it's been made worse by the Neocons and their Straussian explicitness about lying, among others. I think that President Obama is trying to reverse this, but, unfortunately, trust is quickly damaged and slowly regained.

Thursday, May 05, 2011

An Odd Bird

I tweeted a fairly ambiguous photo the other day of a melanistic Northern Flicker. I have wondered how much the flickers here move around; sometimes there are groups of them, and other times not so much. Most of them look pretty much alike, though, so it's hard to tell.

Not this guy. And it is a guy, with the red whisker mark. He's much darker than the standard Northern Flicker, which is what melanistic means. He was back last night for the picture at the top of the post, and this morning he was shrieking at me as I filled the birdbath. So I guess he's here for a while.

We have had a really lousy week for spring weather; spring is, hands down, the worst season in New Mexico. Wind and unpredictable cold spells. So we had some snow. Here's a black-chinned hummingbird making the best of it. Notice how he's fluffed out. I can't for the life of me figure how something this small doesn't freeze solid, but I guess his heat production exceeds the heat loss. He was sucking down the sugar solution a lot of the time.

Update: the dogs and cats of war.

Show Me The Plutonium!

I've seen a couple of articles lately referencing the fire in Fukushima's spent fuel pools or the core meltdowns through the containment.

If either had happened, we would be seeing a great many radioisotopes in addition to cesium-137 and iodine-131.

When uranium fissions, its nucleus breaks in half, but not the same way every time. So the fission products are elements around half the atomic mass of uranium-235. The neutrons also add to the nuclei of other fuel components to produce other elements, like to uranium-238 to produce plutonium.

Cesium and iodine are soluble in water. Xenon, another fission product, is a gas. They are the only fission products that have been observed. That is consistent with the release of steam and cooling water from the reactors and the spent fuel pools.

If there had been a fire in the cooling pools or a serious breach of reactor containment, those other fission products, as well as uranium and plutonium, would be released as well. So far, the reports of such elements have been erroneous.

And the data is not just from TEPCO. The cesium and iodine are being detected around the globe. The other elements would be too, if they were there.

Radiation Dose and Cancer Risk: Some Numbers

I really like numbers, and it’s taken me some time to get to them in discussing risk to health from radiation. I also like to know what goes into the numbers, so I’ve taken some time working through BEIR VII. Now I’m feeling that I (almost) know what I’m doing, I can start to answer the question: what risk of cancer does a particular exposure to radiation carry?

I’ve considered how radiation standards are developed in two earlier posts. These posts have been among the most difficult I’ve written; it’s no wonder that so many people have a hard time understanding what radiation standards mean. Reporters try to put radiation measurements in perspective by saying that they are some multiple of the standards, sometimes large multiples. But unless we know what sort of harm the standards and increases from them represent, we still lack perspective. That is the relationship I’m trying to illuminate for others and understand better myself.

The allowable exposures to members of the public and to radiation workers are given in the chart by Randall Monroe (XKCD). For a member of the public, 1 millisievert/year (mSv/year). For a radiation worker, 50 mSv/year. Under extreme conditions, the worker’s exposure could go up to 100 mSv while protecting valuable property or 250 mSv in protecting human life. That’s, as the news articles like to say, a factor of 250 in exposure. But what does it mean for the risk of cancer?

Let’s consult BEIR VII again. For this post, I want to make the numbers as plain as possible, so I will omit most qualifications. There are many in BEIR VII, and I will discuss some of them later.

The most directly usable tables are those in Chapter 12 and Annex 12D. They provide the lifetime attributable risk of cancer incidence and mortality for single exposures at various ages. “Lifetime attributable risk” means those cancers attributable to radiation over and above the normal cancer incidence. BEIR VII assumes that the risk is proportional to the amount of exposure, the linear no-threshhold hypothesis. This hypothesis is the subject of some controversy, which BEIR VII addresses and concludes that it is a reasonable assumption. It is a conservative assumption, because it results in a higher calculated risk of cancer than alternative assumptions. So the numbers in this post might be considered an upper bound.

The tables also give the exposures in grays, rather than sieverts. Gray is the measure of deposited energy, and sievert is the measure of biological effect. For most of what I’m considering, it’s reasonable to assume that the two are numerically equal.

For the public limit, the BEIR VII committee’s preferred estimate is in Table 12-6. 1 mSv per year throughout life, the expectation is that there will be 550 cases of cancer and 290 deaths per 100,000 males, 970 cases and 460 deaths per 100,000 females. due to this incremental radiation exposure.

The worker limit, 50 mSv per year, does not apply to an entire lifetime because people do not work over their entire life. Table 12D-3 provides data for yearly exposures of 1 mGy per year throughout life and 10 mGy per year over ages 18 – 65. It is evident in the table that cancer incidence and death rates are not a simple multiple of the exposures, but I will use that method anyway; it gives a high estimate. For 50 mSv per year exposure for men, the risks for cancer incidence and mortality are 15,295 and 8,500 per 100,000 people; for women, the corresponding numbers are 21,475 and 11,945. But most workers are not exposed over that entire time range, nor do they receive the full 50mSv per year. Although my work with radioactive materials was occasional rather than the regular work of, say, a reactor technician, my typical exposures were under 1 mSv per year.

The lifetime attributable risks of cancer incidence and mortality of the one-time doses, 100 mSv for protection of valuable property and 250 mSv for protection of human life, are found in Tables 12D-1 and 12D-2. If we assume that the workers are male and their age is 40, then 100 mSv gives 648 cancer cases and 337 cancer deaths per 100,000 people exposed; 250 mSv gives 1620 cancer cases and 843 cancer deaths per 100,000 people exposed.

The incidence of genetic mutations is so small that BEIR VII does not include an attempt to measure it.

Doses over a lifetime are not strictly additive, although this claim has been made in the media. The BEIR VII tables indicate different effects for one-time doses and doses over time. Radiation therapy for cancer frequently involved much higher cumulative doses than those expected to cause death in a single exposure.

My next post will consider the likely errors on these numbers, the qualifications stated in BEIR VII, and some questions raised by others about BEIR VII, along with the baseline incidence of cancer. Unfortunately, that last is almost as hard to pull out of the reports as the numbers on radiation effects I’ve given here. For some comparison, Ethel S. Gilbert, a radiation epidemiologist at the National Cancer Institute, was quoted in the New York Times on the cancer risk to Americans from fallout from atmospheric nuclear weapons tests. That projection, apparently the same sort of numbers as what I’ve given above, is 11,000 more deaths from solid cancers compared with the normal rate of 40 million cancer fatalities.

Cross-posted at BMJ Blog.

This post should be read in conjunction with "Limitations of BEIR VII Estimates of Radiation Risk."

Wednesday, May 04, 2011

Bits and Pieces - May 4, 2011

Let the hand-wringing start. I'm on an e-mail list that includes a number of people who find the US wrong no matter what. So they now are trying to convince themselves that the US killed Osama bin Laden in cold blood, illegally, should have brought him back alive for a trial. Here's some other opinion on the matter, the way I'm leaning:

From a United Nations human rights expert who has severely criticized Guantanamo.

From Stephen Walt.

Added later: As usual, John Cole makes a lot of sense.

Juan Cole comes at the issue in a slightly different way.

Gary Sick: Does Islamism have a future?

Tuesday, May 03, 2011

Bits and Pieces - May 2, 2011

Tracking bin Laden as a class project.

Many thanks to Ezra Klein for summarizing Bruce Schneier's TED talk. I'm just not fond of watching video on my computer, except for events in progress, Jon Stewart, and Steven Colbert.

Get up early and see six planets.

Who is it who wants to impose sharia on the United States?

The Obligatory Bin Laden Post

Yes, the title isn't even original. I saw it yesterday somewhere, and when I googled it, many more turned up. It's not clear to me that I have much to add to what's being said.

As far as global strategy goes, most of the possible analyses have been given. If I'm not going to comment on something, I usually like to provide analyses that I've found worthwhile, but I'm unimpressed so far. Osama had become less important to his now-franchised al Qaeda, and the young people in the Arab uprisings have other agendas.

The TSA isn't going away and will insist that you be x-rayed, your liquids and gels limited, and your shoes off, just like a convict, just like yesterday and the day before.

It does seem that the Republicans have lost some political purchase. No longer can they accuse a Democratic president of fecklessness, his having gotten the man that their president gave up on. I'm wondering if this will set them back enough that they become slightly more rational in issues like the debt ceiling, but they, like Osama are true believers to whom anything like reasonableness is a defeat.

Pakistan may have some rethinking and explaining to do, but it looks like the US and Pakistan have decided to try to ignore the more uncomfortable facts for a while.

I guess I ceased to think of the search for Osama bin Laden as being meaningful some long time back. I've never been impressed with the "great man" theories of history, and I never thought al Qaeda to be the existential threat that some desired. It's mostly a relief to have that box checked, off the agenda, so that we can move on.

Good job by everyone involved: the national security group in that photo that's making the rounds, and all the military and CIA involved in the operation.

Afterthought: Another thing that isn't going to change, might get worse, is that The Terrists Will Attack Us. With WMD. Their desire may increase, but their capability is likely to go down, particularly now that Osama's computer is in US hands. Now that the Armchair Generalist has gone silent, I may have to polish up my snark for this sort of thing. I'm particularly disappointed that this warning came from Richard Lugar, who has been a voice for sense on nuclear weapons.
Sigger's Law: "As any discussion on terrorism grows longer, the probability of attributing terrorists with nuclear weapons (or similar destructive capabilities) approaches 1." Corollary to Sigger's Law: "Once such an observation is made, the discussion is finished and whoever mentioned terrorist possession of nuclear weapons has automatically lost whatever debate was in progress."