The devastating March 2011 earthquake in Japan is now six months behind us. Tragically, more than 15,000 people lost their lives.

I heard a speaker a few weeks ago suggest that her Father’s cancer may have resulted from living too close to the Three Mile Island incident. Admittedly (and to her credit) she did not insist that the nuclear accident was the cause, only suggested that it might be the cause. And (like all wobble language) it is hard to argue against such claims. About 140,000 people evacuated from a region around the plant with a radius of 20 miles. Afterward, about 2 additional cases of cancer resulted beyond what would be expected, statistically. The normal incidence of cancer is about 400-500 per 100,000 people per year. So it is completely impossible to discriminate between of the people who lived around TMI and would normally get cancer and the two extra cases that resulted from the accident. Maybe her father was one of those people. But the likelihood is slim.

I (of course) did not confront a grieving woman after the death of her father. Her statistical analysis was off, but her emotions took precedence. Yet her attribution of that cancer to TMI leaves her audience with a little more fear of radiation and nuclear power.

With that in mind, I think back to the Japanese earthquake. Again, tragically, 15,000 people lost their lives.  A dam broke and drowned at least four people. Living in front of a dam carries some risk.  Are dams a threat to humanity? No, and neither are nuclear power plants. So far, as of yet, not one person has died from radiation.

Alarmists would have everyone believe that the nuclear disaster associated with the accident was far more terrible than the earthquake itself. If that were true, we would expect that there would be many thousands of sick or dead people due to radiation. But there are none yet. Now, if the nuclear tragedy doubles the risk of cancer across a 30 mile swath of Japan containing 100,000 people, we might see 500 additional cases of cancer per year. That is a terrible (and unrealistically bad) scenario, but it is (still) not remotely so terrible as a single tragedy killing 15,000 people without warning.

So it is strange to me that irrational fears resulting from Fukushima nuclear disaster will have so great an emotional impact relative to the natural disaster. And it may be that the emotion will have a lot bigger political impact than reality.

-Peter

P.S. To be fair, one rad-worker has leukemia, but that disease takes years to develop, so is not likely due to the meltdown.

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Let’s assume that the Fukushima Daiichi reactors collectively manage a plume the size of a square kilometer with radiation levels of 400 mSv/hour. Now, to get comparable numbers we need to get the dose per year:

400 x 24 x 365 = 3.5 million mSv/year.

Now let’s take that as a uniform distribution over 1 km square and spread it out over the whole earth. Divide by 500 million square km (global distribution).

3.5 million ÷500 million = .007 milliseiverts / year

One Japanese reactor site is not going to sustain that level of emission for a week, much less for a year. Also, 400 mSv/hour is probably a peak value not average value. The real numbers are much, much less. So,the absolute crazy-absurd worst case scenario is less than .007 mSv / year globally.

Typical, natural background radiation levels are about 2.4 millisievert (mSv) per year.  You are already being irradiated at this moment with 342 times the absolute worst case dose from that reactor. So crunch your iodine tablets if it makes you happy, but people in Japan are suffering from the quake and tsunami damage, not radiation. How about we spend our iodine budget on helping out the Red Cross?

Adapted from Pournelle http://www.jerrypournelle.com/