With the recent events here in Japan and my posts about the apparent risks – and more importantly, the apparent lack of them – have come some commentary from doom-and-gloom types. One of the posters brought up detection of radioactive particles in Iceland. Some folks haven’t been doom-and-gloomish, but have been concerned about radiation detected in Sacramento, CA. With so much concern, it’s time to trot out a few more facts.

Iceland: Yes, it’s true: They detected a small amount of radioactive particles at the Icelandic Radiation Safety Authority’s Reykjavik station. According to the authority, levels detected were from 1/10,000 to 1/1,000 the amount found after the Chernobyl incident, which itself caused very little radiation to find its way to Iceland.

Sacramento, CA: The EPA recorded “minuscule levels” of Xenon-133 in Sacramento, it’s true. Meanwhile, fast forward one week and the EPA reports that “monitors across the U.S. show typical fluctuations in background radiation”. Nothing to see here, folks. Move along.

The one dude who decided to label me a “sheeple” for downplaying the risks proclaimed that the governments (both U.S. and Japanese) were lying so as to not induce fear in the populace. All one needs to do is live or travel in the post-9-11 U.S. to see how untrue that is. Fear is used with great expertise by many governments as a means of controlling movement and access to information and services. Fear is used as a way of encouraging people to give up their rights in the name of security. There is quite likely some information – possibly important information – being withheld, but nothing that will radically change the outcome of events in the long term.

Radioactive Iodine: Radioactive isotopes of iodine account for roughly 4% of materials produced by fission of Uranium-235. Within that 4%, approximately 25% is Iodine-129 and 75% is Iodine-131. Iodine-131 has a short half-life of approximately 8 days. This makes it a relatively harmless isotope in small amounts because it means that for any given release, it will pretty much have all decayed within 3 months. The news is less wonderful for Iodine-129, which is probably why, in the spirit of withholding information so as to not panic the public, you don’t see it mentioned on the news here in Japan.

Iodine-129, although a result of nuclear fission in reactors, also occurs to a small extent in the upper atmosphere due to the interaction of high-energy particles with naturally-occurring xenon. Iodine-129 has a rather long half-life of ~15.7 million years, which makes this of significant concern when processing nuclear waste.  Iodine-131 with its short half-life poses very little environmental threat within even weeks of release to the wild.

Because iodine is an essential element for thyroid health, biological uptake is nearly 100% via either inhalation or ingestion via the gastrointestinal tract. And because of its connection to thyroid function, it should be no surprise that iodine preferentially binds to thyroid tissue. This binding is important to health, but is also the primary concern when dealing with radioactive isotopes. Since iodine is a relatively trace element, the body will uptake as much as it finds in its environment. For this reason, KI tablets offer a mega-dose of stable iodine to cause thyroid saturation. About 30% of the uptake settles into the thyroid. Some 20% is excreted quickly in feces, and the rest is eliminated over the course of days. The 30% that finds its way into the thyroid has a biological half-life ranging from ~11 days for infants up to ~80 days for an adult.

Iodine-129 and -131 experience beta decay, which means they emit beta particles when decaying from unstable to stable form. Beta particles are moderately energetic. Gamma rays are also emitted and are highly energetic, which means that they can be detected outside the body, for example, when uptake in the thyroid is measured by external sensors. Beta particles easily pass through soft tissue and cause damage to DNA by literally shattering DNA strands and knocking out chunks of gene sequences. It’s important to bear in mind, however, that in the world of beta particles and gamma radiation, both of these iodine isotopes are small-time players. They’re at the low-end of the intensity scale, which makes them less of a threat than they could be. What makes them potentially dangerous is the localized accumulation in the thyroid. Thyroid cancer can be a result of damage from unstable iodine. Ironically, Iodine-131 is often used in the treatment of thyroid cancer.

Radioactive Cesium: This is the other element that’s been in the news here in Japan, especially making headlines with regard to spinach contamination. Cesium isotopes from nuclear fission generally come in two flavours: Cesium-134 and Cesium-137. The most common of the two is Cesium-137. It is strongly radioactive and, thus, more of an environmental concern than its little brother, Cesium-134.

Cesium is taken into the body via ingestion or inhalation. Within the body, it acts very much like potassium, which means it spreads out pretty evenly within the body’s soft tissues. Because of the large mass of muscle tissue, this is where one would find most concentrations of cesium. Like potassium, cesium is water-soluble, which means that it passes out of the body via urine, and it happens fairly quickly. One of the most effective ways, therefore, to protect yourself from harmful effects of ingesting cesium is to stay well hydrated. Hydration is THE key to successful detox from any harmful substances within the body.

Cesium-137 unfortunately offers both internal and external health risks due to its decay to Barium-137m and the further decay and release of strong gamma radiation. This makes for a sort of 1-2 double-whammy. As with iodine, the health risks associated with exposure to cesium primarily lay in inducing cancer. In most adults, 10% of uptake is passed within 2 days. The remainder has a biological half-life of ~110 days, meaning that once exposure is contained, the body will be rid of any radioactive isotopes within a few months.

Putting It All Into Perspective

As always, what all this means to us is a matter of context. First off, to alleviate the fears of folks in the U.S. and Canada: Unless you’re having a domestic nuclear crisis of your own, you don’t have anything to worry about with regard to the current state of affairs here in Japan. Current numbers point to the fact that 20,000 out of 100,000 (that’s 20%) are predicted to die of cancers from other causes in the U.S. Current numbers indicate that 0 out of 100,000 people are expected to die from cancer caused by fallout from Fukushima. That’s 0%.

For those of us in Japan, the numbers are only moderately different. We have a significant population within the 20km “ground zero” radius and a much larger population within a 100km radius. The reality is that people at ground zero have a small increased chance of dying of cancer compared to statistical averages. To put it into perspective, if you were at ground zero during the atomic bombings of Hiroshima or Nagasaki, you had a 4% greater chance of dying of lung cancer. Compare that to the 400% greater chance of dying of lung cancer from smoking a pack of cigarettes a day for 20 years.

No, I’m not making up these numbers. Which is scary because I smoked ~1/2 a pack a day for 27 years. I quit smoking 8 years ago, and I’m hopeful that living, uhm, intentionally will be the ticket to undoing the damage.

Anyway, the point is that if you put it all into perspective, the real risk of significant adverse health effects from exposure to radiation are pretty small. And what risks there are can be somewhat minimized by making intelligent lifestyle choices. If you’re in an area that is directly affected by fallout, you can:

• Drink bottled water from clean sources
• Minimize exposure to non-potable water by taking short showers or sponge baths
• Eat foods known to be free of contaminants
• Remain indoors if radioactive plumes pass overhead
• Avoid exposure to rain during times of higher localized radiation
• Brush off outerwear prior to entering your abode so as to not bring in nuclear materials
• Wear a mask to reduce amount of contaminants inhaled
• Reduce consumption of restaurant and store-bought processed/instant foods, as they’ll definitely be made with available tap water, which may be irradiated
• Cook with bottled water
• Eat plenty of foods with naturally occurring stable iodine, such as sea vegetables, and use sea or rock salt (NOT table salt) on your food
• When washing clothes in water with higher-than-normal radioactive iodine levels, rotate fresh clothes to the back of the drawer so you always wear your oldest-washed clothes first and newest-washed clothes last

Feel free to double- and triple-check the facts as I’ve presented them here. Radiation might be invisible, tasteless and odourless, but it isn’t the bogeyman that many would like to present. Absolutely, radiation is best avoided, and it’s for that very reason that I’m happy to say my kids have been in Okinawa, far from harm, for a while now and won’t return home till April 6. That said, it’s not a simple matter to just pick up and leave, and for many it’s not an option at all.

I hope you’ve found some of the information here to be useful. If nothing else, you should realize that although the risks are real, they’re minimal when compared to all manner of other stuff that we take for granted in daily life. Many of us don’t give drinking 3-4 beer a night a second thought, but that’ll kill you a lot sooner than any of the iodine from Fukushima that has made it to Tokyo. Same goes for other dietary and lifestyle changes. And, heck, don’t get me started on the electromagnetic pollution from the trains here. (Want an eye-opener? Just hold a compass in your hand and watch the needle during acceleration versus coasting/braking. Eep! I’ll write about that in a future article.)

As always, worry and fear are your biggest enemies. You have the facts now, so work with them in meaningful ways. You have the knowledge to make good decisions and not act out of ignorance. You also should know that if you improve your health in all other areas, you’ll be far more likely to be able to tolerate the little exposure you’re likely to experience with no long-term harm done.

Don’t worry. Be healthy.