Tokyo, one month after

I just arrived this morning in Tokyo. I’m here this week for business, and for the Digital Garage New Context Conference. I’m also participating in the project to help deploy a network of connected radiation sensors around Japan.

It’s been almost exactly one month since the devastating Tohoku earthquake and tsunami. The flight here was almost deserted, as many countries still have travel warnings about going to Tokyo (apparently, Singaporeans are actually disallowed travel to Tokyo at the moment). However, as I see it, the amount of radiation I get on the flight to Tokyo is about as much as I’ll get staying here for the week. The flight from Tokyo to Singapore (8 hours length) exposes you to ~33 uSv radiation (taking the measurement of LA-Tokyo as a proxy, which is also 8 hours length). Currently, the level of radiation in Tokyo is around 0.2 uSv/hr. Thus, I would have to spend over 300 hours in Tokyo (over 10 days) to get the same amount of radiation as I would get just getting there and back from Singapore.

We forget that ultimately, we are all nuclear powered. There is this massive, uncontrolled thermonuclear explosion going on right over our heads — we call it the Sun. Going closer to it and clearing earth’s protective atmospheric shield is 100x riskier than going within a hundred miles of the distressed Fukushima reactors. Personally, I’m more concerned about the X-ray machine at the airport — I find myself staring into the guts of the baggage X-ray machine with the red light on more often than I’d like, usually due to some bag stuck on the belt holding up the protective lead flaps that are supposed to shield me from that radiation. I get exposed to that about four or five times per trip.

Of course, the atmospheric readings don’t tell the whole story, there are long-lived isotopes that find their way into the water and food that are hazardous to health. Few people remember this, but Chernobyl covered the EU with Caesium-137, which with a half-life of 30 years, is still very much there; yet I don’t hesitate to go to the regions in the EU that have been covered with the very hazardous, and very much still in existence, isotope.

So all things tallied together, probably the biggest risk I have to my health here is second hand smoke and aftershocks. At the moment, it’s actually safer from the second hand smoke perspective, because there is an epic shortage of cigarettes in Tokyo. Who would have thought that the Fukushima disaster might have in net, a positive impact on the cancer risk of the average Tokyo citizen?

On the other hand, the earthquakes are a very real danger. As a former California resident for a decade, one would think I’ve felt my shakes. However, within a minute of deplaning in Narita, a 6.2 earthquake rocks Japan. That was the most earth-shaking Yokoso I’ve ever received! It definitely woke me up after my red-eye flight — the quake lasted about ten seconds or so, alarms going off, window panels rattling and my legs wobbling beneath me as they negotiate the shaking travellator. The quake triggered an automatic shutdown of the Shinkansen, so I had to take a bus to Shinjuku.

First thing I did when arriving in Shinjuku was buy some bottled water — imported from another country, since in my assessment there is a real risk of tapwater contamination. The shelves at the Family Mart were about half-bare at around 10AM. Certainly, goods are making their way in, but I can tell demand is high and the supply chain is drawn thin. Still, Tokyo people are scrappy and resilient, it’s business as usual here, and everyone is getting along with life.

10 Responses to “Tokyo, one month after”

  1. […] Tokyo, one month after @ bunnie’s blog… I just arrived this morning in Tokyo. I’m here this week for business, and for the Digital Garage New Context Conference. I’m also participating in the project to help deploy a network of connected radiation sensors around Japan. […]

  2. f4eru says:

    Yes, sensor data is incomplete.

    But, in my oppinion, measuring ambient radioactivity is not enough.
    First, it heavily depends on the location and height of the sensor (fallout fixes on/in the floor, mainly), and can be biased, as you told.

    More important is the amount and activity of particles & gasses that are in suspension in the air.
    Measuring these can only be done using calibrated air pumps and filters, coupled with detectors (ideally a gamma spectrometer)
    example here :
    graphic here :

    After the beginning of the chernobyl accident, many people were contaminated mainly by air and food.
    In the area where I come from (in France) which some thousands of km away from Tchernobyl, the air contamination & dose was similar in 1986 as in Tokyo mid-march, as a consequence, many people that were born 1983-1987 have tyroid deficiencies (proving that it was early contamination, and not external gamma exposition)

    The japanese authorities never mention these facts.

    As the air contamination is still ongoing, It would be really great if your sensor network would have simple & cheap air analysis capability, even without spectrometry, this data is today cruelly missing, and abolutely necessary for risk analysis.

  3. Dave Kushner says:

    Hey, Dave from RollingStone/Wired here. Can you email me asap, I want to interview you for a story I’m working on. Thanks.

  4. chuck says:

    A former California resident?

    Did Bunnie leave Chumby Industries?

  5. Russell says:

    Bunnie —

    It’s important to remember that radiation levels should always be taken with respect to the background. There is no such thing as a radiation-free environment.

    0.2 uSv/hr is not really above background. Measurements in San Fransisco and New York bounce around between 0.1 and 0.5 uSv/hr, and they are not affected in any biologically relevant way by the radiation released from

    So, while it is correct that you will accumulate the same amount of radiation exposure by spending 300 hours in Tokyo as you did by flying there, it is important to mention that you would accumulate almost EXACTLY the same amount had you simply stayed in Singapore, or had you flown to any city in the world (except maybe Denver or Quito).


    • f4eru says:

      Russel, this applies only if you don’t breathe and eat.
      You get much a higher dosis by eating and breathing particules, than staying nearby to these particules. The reason is that with external nucleides, you get only a small fraction of the rays they emit during the time you are around, whereas internal contamination, you get the total dose released by this nucleides, alpha, beta, and gamma rays, for the remaining of your life.
      So measuring only ambient radiation has no real meaning.

  6. Jeff B says:

    bunnie, excellent article. 1000x more concise and researched than most news sites. Have you gone through a backscatter x-ray at an airport? What are you thoughts on that? There is a claim that even though the dose is low it is absorbed differently due to the energy involved and may pose a greater risk than we assume.

  7. Net Semi says:

    Great article. I am in and out of airports 3-4 times a month. I wish there was another way to scan everyone without using x-ray machines. I feel bad for the TSA operator who has to sit in front of that machine eveyday

  8. Granted what has been in the news lately about nuclear melt down etc. is scary, the fact is that nuclear power is still cleaner and far more efficient than fossil fuels, and tends to create less environmental damage than damns.