Combined with surface-water samples taken by commercial "ships of opportunity" in a program organized by Aoyama, these data show cesium
mixing down into the ocean and flowing east at a rate of about 7 kilometers per day.
Studies of cesium
in fish are not enough, Buesseler argues 6 to make truly informed decisions about potential contamination of seafood, we need to better understand the dynamics of how radioactive bits of material accumulate in the environment.
The meat of two of those cows remains, and was found to have radioactive cesium
levels below the government-fixed limit, the Yokohama municipal government said Friday.
However, a redefinition of the second, now based on a specific property of cesium
, may be decades away, says Zondy.
The model 8860 has considerable less complexity and parts count than typical cesium
beam standards, thus providing a much greater MTBF.
Fish also excrete cesium
fairly efficiently, losing a few percent per day.
The Japanese government recently lowered its maximum safety limit for radioactive cesium
isotopes to 100 bq per kilogram in wet weight -- equivalent to about 400 bq per kilogram of dried meat, the authors say.
Cows at the Minamisoma farm are believed to have been exposed to radiation internally because they were fed straw that contained radioactive cesium
at levels far above the allowable limit, probably because it had been kept outdoors.
Detectors at two other high-latitude sites--one in Iceland, the other on the remote Norwegian island of Spitsbergen--have detected cesium
far less often.
Yoshihiro Shiraiwa, of the University of Tsukuba, found that 17 microalgae, aquatic plants and algae in the region are able to efficiently remove radioactive cesium
, iodine and strontium from the environment.