"Dose": the doses the Japanese government is publishing (e.g. here) are not a measure of risk. The data are for Caesium 137 which is easy to monitor because it is a strong gamma emitter. The data should be regarded as a signal for the very likely presence of the dangerous alpha emitting radionuclides like Uranium and beta emitters like Strontium-90 which are very hard to detect.
Food - LLRC advice: Vegetables and other foodstuffs showing more than 50 Bq/Kg Caesium indicate airborne contamination with other radionuclides. If food shows more than 50 Bq/Kg don't eat it inless you have absolutely no choice.
The Japanese government should immediately ask for international food aid supplies to prevent its people eating contaminated food.
Early signs of health damage: We have received information from people in the Tokyo region stating that they have swollen lymph nodes and sores in their nostrils. These are indicators that they have probably inhaled particles of Plutonium and Uranium.
LLRC advice: unless it is absolutely impossible to leave, evacuate to areas where there has been no fallout - check MEXT data (English) or MEXT data (Japanese) .
To evacuate or not? Here is a novel scientific approach to the problem of quantifying the health effects of radioactive pollution.
Put simply, in an area now contaminated to a level of 1 microsievert per hour the fallout raises every individual person's risk of getting cancer in the next 10 years by 11%.
How do we know this?
The Japanese authorities are publishing data on contamination levels in the form of hourly dose rates from Caesium137. It is therefore possible to calculate the cancer yield using the same criteria as used by Tondel and colleagues in a robust but conservative study of cancer in Sweden after Chernobyl. Sweden is known to have been contaminated with Uranium fuel although fallout mapping generally used data for Caesium, just as in Japan now, exactly 25 years later. Tondel and colleagues found an 11% increase in cancer incidence for each 100 kiloBecquerels Caesium137 on each square metre of ground. The cancers were expressed (diagnosed) in a ten year period; cancers appearing later than 10 years are of course possible but were not included in Tondel's study.
The detailed method has been published
Simply, to calculate the additional risk from fallout,
- download the charts for your prefecture from MEXT data (English) or MEXT data (Japanese):
- Calculate the average rate; it is given in microsieverts per hour (µSv/h). (Exclude any short-term peaks as these will have been caused by radioactivity landing on the detectors and associated structures; it will since have been washed off by rain.)
- Find the historical background rate for your area, given as Range of past usual figures at the bottom of the charts (typical values are 0.017 - 0.1) Subtract this from your average.
- Multiply the result by 1565. Your new result will be the number of additional, fallout-related cancers expected in ten years for every 100,000 people in the population of your prefecture (This is over and above the pre-accident rate, calculated for all malignancies in the Japanese population.)
We recommend you save the MEXT data sheets in case the government deletes them. It is important to know the true historical levels so that the additional exposure from fallout can be calculated in future.)
We recommend you to download (free) the book on Chernobyl's effect on human, animal and plant life published last year by the New York Academy of Sciences. All you need is to click on this link. This book tells the facts as scientists have seen, measured and counted them, free of the dogma of "dose". This means they have not ignored the evidence of their own eyes just because it isn't predicted by the ICRP model.
This set of Recommendations from the European Committee on Radiation Risk is also a free download. It provides the scientific material to allow the authorities in Japan to regulate industry discharges on a rational scientific basis and to take precautionary action to protect the public. Unlike the recommendations of the International Commission on Radiological Protection the ECRR advice is specifically intended to apply to post-accident scenarios.
Earlier material from this home page has been removed and will be archived on a separate part of the site. For a few hours it will not be visible. We apologise for the delay - the emergency in Japan has placed demands on LLRC at levels we have never before experienced. For the same reason we are not able to answer all emails. We read them all, but there isn't enough time in the day to answer them all.
Here is Inside report from Fukushima nuclear reactor evacuation zone, a video showing radiation levels on a dangerous journey approaching from the south. on this site. http://ht.ly/4yeJd