John on March 21, 2011 at 9:09 am
There is concern over the short term effect the Fukushima incident is having on crops and water supplies in nearby areas of Japan:
Japanese and U.S. officials gave additional indications of progress in efforts to stabilize the Fukushima nuclear plant, but the list of tainted agricultural products grew Monday to include canola and chrysanthemum greens, a day after milk and spinach showed traces of radioactive isotopes.
The food samples were taken from areas as far as 43 miles from the Fukushima Daiichi nuclear plant, Japanese officials said, and some registered nearly seven times the allowable levels of the radioactive isotope iodine-131, a hazardous byproduct of nuclear fission that can cause thyroid cancer…
The government also said it had found higher-than-average levels of radioactive materials in the air and tap water in Tokyo and elsewhere in Japan. Those levels pose no threat to human health, officials said, but as a precaution, people were urged to avoid getting wet by rain.
The main culprit seems to be Iodine 131 which is absorbed by the thyroid if consumed. I-131 was the cause of many long term health problems related to the Chernobyl disaster because, for days after the meltdown, people continued to eat food (and drink milk) that had been contaminated. This was particularly harmful to children, some of whom have become ill with cancer only years later.
The levels of I-131 don’t seem to be very high in Japan but, out of caution, the government has expanded testing and individual prefectures have put moratoriums on the sale of some products. Again, this isn’t cause for panic as the levels seem to be relatively low, but it is cause for caution and perhaps some preventative measures (such as giving Iodine pills to vulnerable children).
The good news is that I-131 has a short half life of just 8 days. That means that in two weeks the amount remaining will be about 1/4 of what it is now. If TEPCO can get the cooling at the reactors back online, this problem will go away in a fairly short period of time. If, on the other hand, they are forced to vent more steam from reactor #3 as they had planned to do yesterday, the situation could obviously get worse.
Addendum: The government has asked the governors of 4 prefectures not to ship milk or spinach because of concern about contamination.
Category: Foreign Affairs |