The other day I read a headline at The Asahi Shimbun that made me pause and read the entire article carefully.
Please note that the headline states that the Director General of the UN FAO is "convinced" that Fukushima food is safe to eat.
However, if you read his actual words, as quoted in the article, you will see that he is not in fact arguing that Fukushima food is safe to eat.
Rather, what he is saying is at this "moment" the agency sees "no immediate problem":
Yukie Yamao. (2017). U.N. food agency ‘convinced’ that Fukushima food is safe to eat. The Asahi Shimbun http://www.asahi.com/ajw/articles/AJ201705080043.htmlWhenever I read "no immediate" risk, I know that there are very likely to be long-term risks.
ROME--Food produced in Fukushima Prefecture is safe, but continued monitoring will be needed to ensure that remains the case, according to the U.N. Food and Agricultural Organization’s top official.
“We’ve been following this issue very closely,” said FAO Director-General Jose Graziano da Silva in a recent interview with The Asahi Shimbun, referring to the safety of agricultural products and other food items grown and manufactured in the prefecture.
“We are also periodically testing samples to certify that the food presents no danger to human beings. For the moment we are convinced that there is no immediate problem with the food coming from that area.”
He added that maintaining control over the situation is crucial.
Long-term risks derive from chronic exposure to elevated gamma, beta and alpha radiation from sources internal and external to human bodies.
Concentration of radioactive isotopes - such as cesium-137, iodine-131, and strontium-90 - in food is a well-established problem and poses risk for internal contamination and bio-accumulation in biological bodies.
Japan has historically had strict standards for radionuclides in food compared to the US, but even low-levels of isotopes in food can create problems over time. For example, strontium-90 ends up in bone and teeth. Most isotopes are chemically toxic in addition to being radioactive.
Monkeys living in Fukushima have been found to have bio-accumulated radio-cesium:
Fukushima monkeys show signs of radiation exposure Livescience.com July 24, 2014, http://www.cbsnews.com/news/fukushima-monkeys-blood-shows-signs-of-radiation-exposure/
The results showed Fukushima monkeys had lower counts of red and white blood cells, and other blood parts compared with 31 monkeys from Shimokita Penisula in northern Japan. The researchers also found radioactive cesium in the muscles of Fukushima monkeys, ranging from 78 to 1778 becquerels (units of radioactivity representing decay per second) per kilogram, but they didn't find any in Shimokita monkeys. [7 Craziest Ways Japan's Earthquake Affected Earth] Exposure to radioactive materials may have contributed to the blood changes seen in Fukushima monkeys, study researchers Shin-ichi Hayama and colleagues wrote in their study, published today in the journal Scientific Reports. Low blood cell counts could be a sign of a compromised immune system and could potentially make the monkeys vulnerable to infectious diseases, the researchers said.
Here is the relevant academic publication and an excerpt from the abstract, that describes cesium concentrations:
Kazuhiko Ochiai , Shin-ichi Hayama , Sachie Nakiri et al "Low blood cell counts in wild Japanese monkeys after the Fukushima Daiichi nuclear disaster,"Scientific Reports 4, Article number: 5793 (2014) doi:10.1038/srep05793, http://www.nature.com/articles/srep05793The study in Scientific Reports detected cesium levels ranging from 78-1778 Bq/kg in monkey muscle. What are the implications for monkeys bio-accumulating cesium in their muscles? My guess is that what happens to monkeys is likely to follow what happens to people.
[excerpted] Total muscle cesium concentration in Fukushima monkeys was in the range of 78–1778 Bq/kg, whereas the level of cesium was below the detection limit in all Shimokita monkeys. Compared with Shimokita monkeys, Fukushima monkeys had significantly low white and red blood cell counts, hemoglobin, and hematocrit, and the white blood cell count in immature monkeys showed a significant negative correlation with muscle cesium concentration. These results suggest that the exposure to some form of radioactive material contributed to hematological changes in Fukushima monkeys.
In a 2003 video titled Nuclear Controversies by Vladimir Tchertkoff,Professor Yury Bandazhevsky (former director of the Medical Institute in Gomel), states that based on his research on children exposed to radiocesium from Chernobyl, ‘Over 50 Bq/kg of body weight lead to irreversible lesions in vital organs.’
In a short summary of his work published in 2003, Bandazhevsky described high levels of Cesium-137 bioaccumulation in Chernobyl children’s heart and endocrine glands, particularly the thyroid gland, the adrenals, and the pancreas. He also found high levels in the thymus and the spleen. He found higher levels of bio-accumulation in children than adults. This research demonstrates how radiocesium bioacccumulates within organs and establishes the vulnerability of young people to that process.
Is Fukushima food safe? Based on the monkey research and comments made by the head of the FAO, my conclusion is that Fukushima momentarily poses no immediate risks but long-term consumption could lead to bioaccumulation of radionuclildes, a situation which probably is not, at all, limited to Japan, and poses excess risks for disease and disability.