Is Sushi Now Radiocative?

Irrational fears set our hair on fire.

Posted Apr 07, 2011

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As a bald man, my hair-on-fire days are long since over. But that doesn't make me impervious to ill-founded fears. Hopefully, I've had enough practice to realize when the facts behind my fear don't fit. Irrational conclusions that we all make fall under the screwy-thinking category called "cognitive errors." In my opinion, Thomas Gilovitch's How We Know What Isn't So, is still the best book for laying out how the mind is superbly skilled at making bad judgments. Despite abundant research on this subject, we continue to make systematic errors in our thinking. Let's take the disaster in Japan.

Observation 1: People fear what they don't understand. Coal and oil cause far more deaths than nuclear fuels: five times as many accidental worker deaths, 470 times as many deaths due to air pollution, and greater than 1,000 times as many serious illnesses from emphysema to cancer. Because it is so familiar nobody insists that we shut down coal mines even though coal-fired power puts out ten times as much radiation per unit power than nuclear power stations do. Ionizing radiation is not unique to nuclear power. Our solar system is, always has been, and always will be radioactive.

Relative safety of nuclear power

Coal kills 4,000 times as many people as nuclear does.

According to the Lifeboat Foundation, for every person killed by nuclear power, 4,000 die from coal, adjusted for the same amount of power produced (see figure). Did you know this? Now that you do know, what do you think? Did you know that rooftop solar is several times more lethal than nuclear power?

Observation 2:
Our personal behavior biases our estimates of risk. People worry about airplane crashes, yet think nothing about the car ride home that is a thousand times more likely to kill them. Riding in a car many times and having not been killed, a person fallaciously calculates that cars are "safe." Similarly, parents who fear that the measles-mumps-rubella vaccine will make their child autistic risk the serious and sometimes fatal consequences of those three common childhood infections. (Parenthetically the alleged causal link was thoroughly disproved, and the doctor who made the claims was expelled from Britain's General Medical Council.)

Society has little knowledge of radiation, yet we live in a naturally radioactive universe that delivers each of us about 350 milli-rem (mrem) of radiation per year. A cross-country plane flight gives a person 4 mrem per trip for the same reason that living high up in Denver exposes one to more cosmic radiation than a person living at sea level. A routine chest X-ray delivers 10 mrem per film. Watching TV doses you with 30 mrem per year because of TV's low-energy X-rays. If you live in a brick house, naturally occurring uranium and thorium in the soil gives you 75 mrem per year. Smokers are particularly ironic. Besides carbon dioxide, tar, and nicotine, a 1.5 pack smoker exposes himself to radioactive lead and polonium for a yearly radiation exposure of 1300 mrem. Each cigarette is equal to one chest X-ray. Second-hand smoke gives someone living with a smoker the equivalent of 12 chest X-rays per year. Instead of worrying about sushi from Japan stop smoking if you do smoke, and never start if you don't.

Observation 3: People discount data that conflicts with what they already believe. Today's news is full of worry about radiation wafting from Japan. Click the link and see if you recognize any of your own cognitive errors. Like Pavlov's dogs, those whose hair is on fire predictably raise the issue of Chernobyl. Mushrooms growing in Eastern Europe now show increased level of radiation, they say. Wild hogs eat those mushrooms. Hunters kill those wild boars. That same logic extends the threat to soy, seaweed, and Pacific seafood catch. We are all doomed. God forbid we should ever eat sushi again.

Heigh ho. The body repairs radiation damage when the exposure is spread out over time. That is one reason why higher-than-average cancer rates or genetic defects don't occur in populations living in areas of high background exposure, such as Denver. Yet a local doctor in Arizona, 6,000 miles from Japan, is testing fish for radiation while vendors closer by in Guam have determined that it is safe to eat fish. What do you think of that discrepancy?

Observation 4: We are reluctant to educate ourselves. The Atomic Test Museum in Las Vegas gives visitors a healthy understanding of radiation, as does Los Alamos, which has been running since 1943. The theatrical monologist Mike Daisey has a thoughtful, and hilarious, take on touring nuclear test craters in New Mexico's Alamagordo site.

Nothing is perfectly safe. Chasing perfection distracts us from improving what we already have. The solution to safer nuclear devices is continually improved engineering such as "walk away" reactors that shut down using gravity without the need for any human intervention. The design of the Fukushima Daiichi reactors is 50 years-old, and the 2004 earthquake should have shown that they were inadequately protected against tsunamis. Blame human error, not nuclear energy. For those wary of engineering solutions there is another option: buy a Geiger counter.