BOISE -- The Environmental Protection Agency has detected very low levels of radiation from Japan's damaged nuclear power plant in drinking water in two U.S. cities -- Richland, Wash., and Boise, Idaho.
"These levels are very, very low, trace, minuscule amounts," said Jonathan Edwards, Director of Radiation Protection Division with the EPA.
This isn't the first radiation from the Fukushima nuclear plant detected in Boise.
Low levels of radiation were first detected in air samples from Boise on March 21. Minuscule levels were found in Boise's precipitation on March 22. Those levels were among the highest in the country. But they pose no public health concern, according to the EPA. Then on March 28, the EPA found very low levels of radiation in Boise's drinking water.
A spokesperson for Idaho's Department of Environmental Quality says the drinking water sample taken in Boise came from a surface water source, and therefore, not surprising radiation was present, given just days earlier it was detected in precipitation.
The EPA says they know the radiation came from the Fukushima nuclear plant because iodine-131 is not typically in the environment and it has a short half-life of eight days.
"Because of that short half-life it's not typically in the environment and so when we do pick it up we know it comes from some kind of fission event," said Edwards. "And so these results are very much in keeping with what would expect from a very diffuse and diluted release that would have traveled across the country."
The agency says boiling tap water as a precaution isn't necessary. In fact, the EPA is making no recommendations along those lines.
"With radiation, boiling it does not affect it," said Edwards. "But again, these levels are so, so low. And in entirely keeping with what we expected with this. There are no none public health implications at all. And you shouldn't just take this as bland government assurances."
The EPA says the amount of radiation detected in Boise's drinking water is so low -- about 0.2 picocuries per liter -- an infant would have to drink almost 7,000 liters of this water to receive a radiation dose equivalent to a day's worth of the natural background radiation exposure we experience continuously from natural sources of radioactivity in our environment.