April 29 2011 Update
WA State pulls back on radiation testing
Radiation from Japan has been so miniscule in Washington that health officials announced Thursday that they're ending regular rainwater tests and reducing daily air tests for radioactive material. The state Department of Health had started daily air monitoring for radioactive iodine shortly after a tsunami damaged Japan's nuclear reactors in Fukushima in March. Since then, all detected levels have been far below levels that would cause health concerns, officials said. Radioactive levels have also been dropping, often below detectable amounts. The health department said air monitoring will now be done weekly. The tests supplement federal testing of air and rainwater in Washington. The tests, which include air monitoring, will continue.
Fisheries Update from Chiba Prefecture
Test results from April 28th revealed no detectable levels of radioactive iodine or cesium in barracuda, alfonsino, and anchovy samples in the Chiba Prefecture. Test results in sardines revealed no detectable levels of radioactive iodine and whereas radioactive cesium levels were detected at 20.6 Bq/kg. However, this level of cesium is below that set Japanese regulations which is 500 Bq/kg.
http://www.jfa.maff.go.jp/e/inspection/pdf/chiba20110428_en.pdf
Beach Debris
Following the massive earthquake and tsunami March 11 in Japan, coastal communities were dragged out to sea, taking houses, cars, boats, and all the trappings of 21st Century life, some of which will make its way to the West Coast on the currents of the North Pacific Gyre, a circle that travels east from Japan to the Pacific Northwest, then down the coast to Southern California and Mexico, before veering west into the ocean again, passing Hawaii on a return trip to Japan. Oceanographers estimate it will be two years before stuff starts washing ashore in the Pacific Northwest. Yet by then much of it will have sunk and the bigger bits will have been smashed up in storms.
But what about radiation?
On April 15, the Japanese government acknowledged dumping more than 10,000 metric tons of radioactive water from the ravaged Fukushima Daiichi nuclear plant, roughly the equivalent of four seconds of flow over Niagara Falls. The water was released in order to make room for the storage of more highly irradiated water.
The report was meant to assuage neighboring countries concerned about contamination in the ocean, a potential violation of international law. According to the report, Tokyo Electric Power Co. (TEPCO), which runs the plant, released 10,393 tons of radioactive water from April 4 to 10. The amount of radiation in the discharged water was about 100 times the legal limit. Iodine-131 was the most common isotope. Cesium-134 and cesium-137 were found at lower levels.
A model created by ASR, Ltd., a coastal and marine consultant, shows radiation traveling on a path similar to floating debris in the ocean on its way to North America and Hawaii.
Yet the vastness of the Pacific and the passage of time will dilute much of the radiation, according to Carl Safina, a marine conservationist, adjunct professor at Stony Brook University and president of the Blue Ocean Institute. In an editorial for CNN on April 7, Safina noted that radioactive iodine has a half life of about eight days. Thus, half of it will be no longer radioactive after a week. Cesium, by contrast, requires about 30 years to degrade by half. Yet it will be found in relatively low concentrations by the time it makes it way to the U.S., Safina said.
Meanwhile, a report by the International Atomic Energy Commission from Tuesday tells how TEPCO continues to monitor radiation levels at several points offshore from Japan: On April 15 levels were four times the legal limit 18 miles off the coast from Fukushima. But the energy commission report indicates radiation levels continue to drop.
http://sports.espn.go.com/action/surfing/news/story?id=6410428&campaign=rss&source=ACTIONHeadlines