Apr. 9 2011 – 8:15 am By Jeff McMahon
…The EPA maximum contaminant level is 3.0, but this is a conservative standard designed to minimize exposure over a lifetime, so EPA does not consider these levels to pose a health threat.
[UPDATE: The FDA’s Derived Intervention Level for iodine-131 in milk is much higher: 4700 picoCuries per liter.]
The cesium-137 found in milk in Vermont is the first cesium detected in milk since the Fukushima-Daichi nuclear accident occurred last month. The sample contained 1.9 picoCuries per liter of cesium-137, which falls under the same 3.0 standard.
Radioactive isotopes accumulate in milk after they spread through the atmosphere, fall to earth in rain or dust, and settle on vegetation, where they are ingested by grazing cattle. Iodine-131 is known to accumulate in the thyroid gland, where it can cause cancer and other thyroid diseases. Cesium-137 accumulates in the body’s soft tissues, where it increases risk of cancer, according to EPA.
Caesium-137‘s presence on Earth is solely do to humans splitting atoms. It is produced from the fission of uranium. So it isn’t a naturally occurring radiation coming from the sun or aquifers it’s from Japan. (if I understand wikipedia correctly – VT4Evolution)