mercoledì 18 aprile 2012

Survivalism and the real radiation contamination in Japan

Japan is catching up with the tradition of bad newspaper articles, depicting an apocalyptic,  post-nuclear vision of the life in the  island. If the term "post-nuclear" might apply to a country that has all but one nuclear reactors off the power production grid, many of the personal views expressed in one recent article were especially puzzling. This is an excerpt of the letter I sent to the editors of the daily newspaper. I hope it might be a useful recap of the situation in Japan. The letter did not contain the links (that unfortunately are in italian, but google translate does a decent job).

Dear Sirs,

in reading your article [...] I cannot help but be puzzled by the content and implications.  
[...] in the article there is no mention of real measurements of environmental or food contamination,  only hearsay and very general and unhelpful comments that would probably better find its place in a personal blog rather than on a daily newspaper that is widely read by the foreign community in Japan and by foreigners that are interested on Japan.
The risk in reading the personal comments and life-style expressed in the article is that all foreigners are mindlessly scared about radiation and/or  that the situation of the radiation in Japan after the Fukushima accident is out of control.
As you might be aware, the foreign press in general, and in particular the Italian one, has been extremely inaccurate and unprofessional in dealing with the accident, its effects and the risks of radiation in Japan and abroad.   This kind of old-maid’s tale articles can be misinterpreted or voluntarily misused by foreign press to depict an incorrect situation in Japan and on the people -  foreigners or not -  living in this country.
Some points that are worth remembering,  at least  to ease the worries of the author:

1.       Radiation in Tokyo area is roughly one third than in Rome (0.1 microSv/h vs 0.3microSv/h and 0.4 at the University of Rome Tor Vergata, near volcanic rocks – personally measured)

2.       Radiation on airplanes is 20 times higher than on the ground. Even though we spend less time on an airplane this is relevant for airline crews.

3.       Radiation in space is 1000 times higher than on ground. No ill effect have been found on astronauts who lived  for months on the International Space Station.

4.       Bananas have 125 Bq/kg of radioactive potassium 40 (higher than the Cesium safety levels of 100 Bq/kg).  It is possible that the process of eliminating cesium and potassium is different, though. (edit May 2012, here  the time of permanence of Cesium in human body).

5.       The amount of food consumed comes into play in calculating the radiation exposure.  Five grams of “radioactive” tea, even assuming  the old limit of 500Bq/kg amount to 0.5 Bq.

6.       A number of independent measurements point to no risk in the food, my colleagues in Italy have tested personally the amount of cesium in rice of Miyagi-ken and found 0.1 Bq/kg, less than 1per mil of what found in bananas.

7.        Chernobyl and Fukushima are two completely different accidents: in the former case the reactor core was exposed and radioactivity was dispersed in the air. This did not happen in Fukushima plant, where most of the radiation went in the water.

8.       Cigarettes contain polonium 210 (the same isotope used to kill the Russian dissident Litvinienko), present in the tobacco due to fertilizers. A two pack per day smoker is exposed to 250 mSv/year in the bronchial region, compared to about 1-3mSv/year of non-exposed persons.  In Europe, every year 5000 people die because of radiation induced cancers in the lungs (this is about 15% of all cancers in lungs).

9.       The highest risk of radiation in Europe is due to radon gas seeping through the underground cracks. This radioactive , but chemically inert gas, can accumulate in places where air is not changed often. 

At this point it should be mentioned that I have been living with two small children and a Japanese wife since before the fateful earthquake and accident at the power plant, and that, even though we took precautions and monitor closely the situation, we do not live in the state of fear that might be mistaken to be typical of foreigners in Japan. The same can be said of my colleagues, Japanese and foreigners  at RIKEN  and the many foreigners living in Japan, equally puzzled by the tone of the article and the discrepancy with their daily lives and behavior.  
This is not to attempt to deny the tragic events of the accident and its devastating implications, but to put them in the correct context and to analyze the situation individually and independently with real measurements.  This is the effort that has to be painstakingly pursued by everyone.  
My main research field is space physics with satellites and radiation environment studies on astronauts, but I am also struggling – for what is possible – to inform on the real situation and correct the excesses and apocalyptic visions that have been evoked in my country since the Fukushima accident.  [...]  
I sincerely hope that – in line with your excellent editorial policy and quality of the articles  that have kept us informed of the situation in Fukushima - of you might publish in the future a “review” article with more circumstantiated numbers, values and  reading, but also on the life in daily Japan,  so that the general public can be made aware of the current situation. If possible, please print the main points of this letter on your newspaper.
yours sincerelly....

It might be worth adding that very cheap and relatively precise geiger counters are available from many shops. Radiation is one of the most easily measurable quantities, also by non-specialists. If you have doubts, it is very easy to make your own measurements.