Overdose or overdo? Doused and scanned for radiation

Whenever you travel, you're sure to carry away some memorable experiences.

I had to walk through a radiation scanner on my visit to Taipei last week. The experience was both nerve-wracking and ridiculous.  This is the kind of thing that makes people unnecessarily worried  (Just ask the UN).  Passengers arriving from Japan were sequestered off for a special check.  The scanner was brown and resembled a thin, lanky doorframe. There were two or three officials wearing masks sitting at a table to one side of the scanner watching to see whether those who passed triggered a red or green light.

I didn't get a chance to take a picture, but I was able to find a video of the scene in Taipei:

There's also this news report.  Of course, everyone who passed through the brown gate triggered the green light. Who knows what the Kafka-esque red light is supposed to indicate...

I think my largest dose of radiation in all of this came from the airport (a trip through the metal detector and round-trip flight.

There was one other odd detail about my flight into Taipei (departure and arrival): a large swatch of translucent blue tape (sticky side up) was set upon the floor of the jet bridge in the space directly before entering the aircraft.  The edges were taped down and the size was so large that you couldn't leap over it without a running start.  At first glance it was kind of comical, but my paranoid brain told me, "You've never had to do this before.  Is this something related to the radiation scare?"  It was sort of like flypaper for humans.  It pulled at your feet as you treaded over it.

Maybe this is just a China Airlines thing, but why both before boarding the aircraft and again when exiting?  Perhaps the strange, sticky tape trap was designed to collect radioactive dust, rather than have it being left aboard like a peanut wrapper tucked into the seat crevice.  Unfortunately for the airlines, if there really is radioactive dust on your shoes, there's probably dust in/on your clothes.  I wonder if those HEPA filters used on aircraft would collect that sort of airborne dust?  How often are those changed, anyway?

The scanning reminded me (ironically) of a similar experience...
In May 2009, I visited Japan during the swine flu scare.   I remember when I landed at Kansai International, a group of Japanese medical personnel boarded my plane clad in goggles, masks, yellow, hooded jumpsuits to screen passengers for elevated body temperatures.   The whole thing was surreal--like some cross between Predator and The Hot Zone.  Two rows behind me, someone was found with an elevated temperature, so half of the plane was quarantined (probably for ten days).

The ordeal didn't end at the airport, either.  Throughout my trip, I was pestered with calls from the Board of Health, as my flight had originated in Huntsville, AL, where there had been several confirmed cases of swine flu in the week leading up to my trip.

Traveling is always an adventure.

So long iodine-131 and 134

It’s been 17 days since the earthquake (the date I posted this and the date I wrote it differ). So long as no more nuclear fission is being produced (this seems likely at this point), the overall quantity should be decreasing, right? The stuff that was produced is still blowing about, though. How long will it take for the iodine produced on the day of the mega-quake to dissipate from the environment?

*Note: My MA is in applied linguistics. Sure, I had high school science and I like to read, but that hardly qualifies me to do more than ask questions and safely operate my microwave oven. If you’re a hard scientist, please feel free to correct any errors in my table.

This post will focus on iodine-131 because it’s become the Charlie Sheen of radionuclides. Iodine-131 is dangerous to living things because it is has highly energetic beta radiation. In other words, it likes to shake its tail feather. Beta radiation from iodine-131 can extend 0.6 – 2 mm. It’s a danger to humans because your thyroid slurps up iodine until its stuffed. Other parts of the body use/absorb iodine, but the thyroid gets its fill first. There’s a pecking order in your body and when it comes to iodine your thyroid is first in line. Unfortunately for us mortals, in its feeding frenzy, the human thyroid doesn’t distinguish between radioactive iodine and stable iodine.

Iodine-131 does have its uses, though. It can be used to treat certain types/stages of thyroid cancer. Getting a little iodine-131 dust on your skin is n reason to panic, as it isn’t rapidly absorbed that way. According to a study by Nyiri and Jannitti (1932), only 1-2% of iodine applied topically is absorbed into the blood stream readily. An additional 8-11% of the iodine applied to the skin will be absorbed into the skin, where it will slowly be released into the bloodstream. 12% of a miniscule amount is...to use a technical expression, “very, very little.”

Breathing in radioactive iodine attached to dust particles and pollen is something that’s been suggested in overseas media. Wearing a mask might protect you breathing in a lungful of pollen and a couple of hitchhiking atoms of iodine-131.

This reminds me of a joke that some BoE members made the other day in the hallway. Right now in Japan, cedar pollen is around its peak. Many people are terribly allergic to the pollen, so they wear masks to minimize their irritation and hay fever. The pollen is so plentiful that it was collecting on the roofs and awnings of buildings in the area. Since the pollen is a wild shade of neon yellow, several teachers made the joke that it was radioactive Godzilla dust, and not pollen at all.

You can see how seriously educators here take the threat of airborne radioactive dust. It’s a non-issue for them at this point.

As I mentioned at the beginning of this post, iodine-131 has a short half-life (roughly eight days). It was already in extremely low concentrations, and continues its rapid decay. Some foreigners in and around Tokyo and Chiba (and their relatives) are worried about recent reports of contaminated water. Admittedly, hearing that your tap water may be contaminated (with anything in however small an amount) is never a reason to celebrate. It’s natural to be concerned, I think. You can’t see it or smell it but you’re told it is there in X quantity.

Maybe the rest of this post will help assuage unreasonable fears by putting the matter into perspective.

The bad news is…if you were exposed to any iodine-131, and you swallowed (water, air, etc), the isotope made its way into your blood (so says Keith Baverstock).

The good news is…even if we assume dose effects to a linear no-threshold model (that is, a constant positive correlation between radiation and risk), your increased risk of cancer from exposure to contaminated tap water is roughly 0.003% for men and 0.02% for women (Hoffman)(It looks like we're all still insurable for cancer, huh?). The influence at this dose is so small, it’s said to be indistinguishable from the normal (random) rate of occurrence in a population. Not only that, but the estimated 0.003% increase in risk for men assumes that you’re drinking 2 L of 200 Bq tap water a day. If you’re over 40, relax-- you’re over 40; you have enough to worry about as it is (try not to light that cigarette, though). If you’re over 40, congratulations…your chances of increased cancer risk from Tokyo tap water seem non-existent (I’m guess that’s got to be the best news that you’ve heard since turning 40). So far, for those of us in and around Tokyo, worrying about low-dose radiation is probably the clearest danger to physical and mental well-being.

It get’s even better (maybe).

The absolute best-case scenario is… being exposed to a low dose of radiation may actually lessen your chances of developing cancer. There’s not a whole lot of evidence for this, and if something seems too good to be true, it probably is...

I’m a cautious guy, so I’m betting that the effect of iodine-131-infused tap water should be null (neither slightly good nor slightly bad). There are simply too many confounding variable to say much of anything about the effects of low dose radiation with confidence.

Am I groundlessly confident? Not really. Am I without concern? My concern is diminishing the more I learn about this (and so should yours!).

First, I should say that I’ve preemptively started on a strict red wine/sake regiment…indefinitely…

That’s got to be reducing my tap water intake, right?

More seriously, though…

I mentioned that Hoffman’s predicted 0.003% increase risk in developing cancer assumes consuming 2 L of 200 Bq of tap water, daily. In Chiba (where I live), the Bq level is significantly lower (0.79 Bq/kg). Even if I “recklessly” drank 6 L of this water, I shouldn’t see anything near as much as a 0.2% increase risk of thyroid cancer from contaminated tap water. Lucky for me, this “risk” is decreasing day-by-day, thanks to iodine-131’s relatively short half-life.

A word of caution, though…

Are you pregnant or preadolescent? Are you an infant or soon-to-be newborn? If so, you should try to avoid drinking contaminated tap water as much as possible. Adolescent development is very sensitive stuff, as you’ve probably heard. If you’re preadolescent and you have to drink the water, don’t panic—your increased risk of cancer (based on the available science) is still very low (but the increase is life-long). The closer to age zero (i.e. fetuses, infants) you are, the more dangerous radiation and carcinogens seem to be. That’s seems pretty intuitive, though.

One thing I was unable to find when preparing this post was this: how quickly is iodine processed by the thyroid? I’m not sure how relevant it is to the discussion of iodine-131, but I’m curious. Is iodine consumption by the thyroid a constant rate, or influenced by exercise, diet, age, gender, genetics, etc? Since metabolic rates differ so greatly among individuals, I’m guessing the rate this fuel is burned by the thyroid also differs…there should be a normal range, though.


If you're using what I've written to make a decision about your health, let me remind you that I'm not a doctor or a scientist, just a concerned reader.

The US Embassy in Tokyo has a Youtube channel

A welcomed video from the US Embassy in Tokyo

The head of the National Cancer Institute, Dr. Norman Coleman, talks about radiation in and around Tokyo.  

Those who are worried would do well to watch this (in order to relax and get some perspective).

Some new words and why I read SF

For along time now—longer than I can remember—I've been interested in how memory works. What is a memory? How do memories persist? How are they stored in the mind? What is stored? How do memories interact? How do memories change over time?

I am always looking for ways to improve memory or learning/uptake. As an educator, I put a lot of weight into Schmidt's noticing hypothesis. When something new is brought to one’s attention incidentally, it is an excellent opportunity to form and flesh out a long-term memory.

I’m a very curious person and I’m always asking questions. As I grow older, I try to be more tactful and show more restraint with my curiosity, but it still sometimes gets me into trouble. I try to learn and absorb as much as I can. One essential part of that process is reading. I try to read widely, regularly, and critically. This isn’t to say that I’m authoritative on anything. The most important thing I’ve realized from reading is how little I know (and how little others know). Luckily, it is this realization that keeps me reading.

One genre that I enjoy is SF. People often ask me why I read SF. For some reason, many people are unable to see the value in science fiction. They are unaware of its most important authors and themes. The best SF is a marriage of the things we value in fiction and science. SF produces some of the finest meditations on origins, reality, identity, relationships, and the future (it also provides some of the most insipid). Fiction provides a wealth of lofty ideas, abstract paintings of dimensions both foreign and familiar; Science provides the craft for ascent. Of course, many people will groan when they discover that I read science texts as well. It’s been my experience that many scientists (physicists, astronomers, etc) already read SF (some of them write it). The best SF, after all, is that which is informed by real science. It explores the future and the paths that might lead us there. It promotes interest in the science behind the fiction (SF encourages science literacy), and thus elliptically draws those of us in a (darker) more distant orbit towards the light of science.

Fiction may allow us to hallucinate, but science can teach us how to reveal the unseen world (fiction is an acid drop; science is a microscope).

Lately there has been a great deal of talk about invisible threats here in Japan. Some of it is hallucinatory fever stuff and some of it is scientific revelation. It’s essential (but at times very difficult) to be able to distinguish between the two. We’re getting snapshots of the larger picture. Unfortunately fitting them altogether is akin to fiddling with a tanagram puzzle: there are many shapes the data can take.

I read SF, so I deal with “far-out” ideas and what ifs. Recently, though, I encountered some things in the media that were a little unfamiliar…how about you? How many of these can you define without peeking?

Seivert (Sv)
Becquerel (Bq)
Neutron beam
Gray (Gy)
Iodine-131 (¹³¹I)
Iodine-134 (¹³⁴I)
Cesium-137 (Cs-137)
Radionuclide
Radiation hormesis
Spent fuel pool
Cold shutdown
Temblor
Dose fractionation
linear no-threshold model (LNT)
Radioresistance

Saturday in Narashino

Things are calming down in Narashino.  I noticed yesterday that a few buildings were recently torn down.  I can't say for certain that all of these were due to the mega-quake (and aftershocks?), but at least one was.  I'll post pictures (before and after) in a later post.

The crisis in Fuskushima is far from solved, but so far the impact is minimal here in Narashino.  Chiba Prefecture continues to post atmospheric radiation readings (gamma) on their site.  Today I translated this document, to make it easier to understand for English readers who cannot read Japanese. I'm just looking for ways to help people involved in all of this.



My translation is publicly viewable via this link.  Clearly these numbers are very encouraging.  The gamma radiation so far has not been dangerous or significantly different from what it was a year ago.  Based on this data, I would say the change in radiation levels here in Chiba so far has been negligible.

My mother used to work as a chemical engineer for the US Environmental Protection Agency. She's been helpful with information on types of radiation. I was browsing the EPA's site today and found this, which gives some useful information on different types of radioactive material. It's not really important for the situation here in Chiba, but it's useful to make sense of some of the terms being thrown around in the media.

There are a bunch of helpful data-driven resources out there to help better understand the situation in Fukushima.  Here's a link to some very helpful presentation slides made by Benjamin Monreal, Assistant Professor in the Department of Physics at UC Santa Barbara.  I encourage those of you who want to learn a little more about the situation in Fukushima to review the entire presentation.  I'll post several slides below that I found especially helpful.  Hopefully Dr. Monreal won't be upset...I added captions beneath each slide.

The atmospheric radiation that we've seen (in Chiba, at least) so far only makes sense to measure in microseiverts, so I feel pretty safe looking at the data.

Fukushima's design and fuel system bears some important differences from Chernobyl.  

This isn't a comfort to many people in Fukushima who had to evacuate their homes, but it clearly could've been much worse. 

The half-life of these isotopes is a little encouraging.  Wow, remove the top 10 cm of soil?  That sounds difficult to do right.  As anyone would quickly tell you, I'm not a scientist (just concerned and wanting to learn).  I wonder if that takes into account rainfall/rates of infiltration, etc.  An earlier slide in the presentation shows which elements (and thus their isotopes) are water soluble.  In any case, this gives you a sobering sense of what some of the long-term effects are going to be around Fukushima.

That's all for now.  I'll try to update again soon.