(11-27-2012, 09:03 PM)UniqueStranger Wrote: Fuk children thyroid cancer...still waiting for more data - from which source?
The question I am grappling with is which of the two sources should one believe? The Japanese Gov't or the independent doctor's second opinions?
Its a little complicated. The Japanese government is trying to calm frightened consumers who have been excited by the independent press. The government has lowered radiation limit to mollify consumers which bans some relatively safe food - which frightens the consumers more.
1. Linear no-threshold model of radiation tolerance is a lie. The author of the model John Gofman knew it was wrong but was to some extent an anti-nuclear activist. The model has no validity below 100 mS/y.
2. The cancer rate is minimum at around 200 mS/y. The normal background radiation is around 3.6 mS/y (US average). The cancer rate at 2 S/y is about the same as the rate at 3.6 mS/y. Keeping the radiation level below 100 mS/y is provably killing people. Admitting this would allow the anti-nuclear activists to be sued just like the tobacco companies were and would make nuclear power much cheaper.
3. Children particularly embryos are at least twice as sensitive as adults. http://www.esri.com/news/arcuser/1012/mo...iging.html. This ESRI article suggests they may be 3 to 5 times more sensitive. Adults have a self repair function for radiation damage that works better if it is kept busy.
4. The US allows some foods have radiation levels up to 2000 Bq/kg (enenews says the limit is 1200). The Japanese limits were 500 Bq/kg before Fukushima and they were lowered to 100 Bq/kg and 50 Bq/kg for baby products.
5. The mercury problem with apex predators like tuna is greater than the radiation threat.
6. 70%-80 of the 3.6 mS/y average yearly dose is due to inhaled compounds (radon and so forth).
7. Only about 10% i(0.4 mS/y) s from consumables. One site equated 56000 Bq to 1.2 mS. So that would mean the US diet includes 17000+ Bq of radioactivity compounds. The average us adult consumes 1700 pounds of food a year so the average is 10 Bq/kg (I had another estimate from other sources was around 15 Bq/kg so average radioactivity in US food is around 10-15 Bq/kg).
On the other hand in some places in Brazil the oranges are over 6000 Bq/kg, and tapioca in some spots in India is over 1200 Bq/kg.
9. Typical soil is 400-500 Bq/kg
10. The US is importing Japanese food that is considered unfit under the new Japanese standard (which is less that 10% of the US limit).
What to think about this...
The new Japanese food radioactivity limits (100 Bq/kg) should keep the Japanese exposure down to that of Denver (6 mS/y). The child exposure should be about 4.5 mS/y worst case. Anything below 100 mS/y should be considered safe so this should be ok assuming the municipal water is clean.
The doctors are talking about thyroid nodules - in the US about 50% of kids have them. The doctors are reporting 43% in Japan. This is really a different issue - since the thyroid problem is due to the long departed Iodine 131 and the food issues are Cesium which doesn't concentrate in the body. The thyroid cancer rate is an indicator, the thyroid abnormalities are so common they really aren't abnormal and really don't indicate anything.
Thyroid = Iodine, the Iodine is long gone and we don't accurately know the exposure so this is a wait and see exercise.
The total Iodine 131 released was 150 to 900 PB (government to alarmist figures). That would be between 1.2 ounces and a cup of Iodine 131. It's all gone.
The total Cesium 134 released was 0.83 kg (about a quart). It is about 1/2 gone.
The total Cesium 137 release was 9.2 kg or about 2 1/2 gallons.