The Woods Hole Oceanographic Institution (WHOI) first detected cesium-134 in seawater samples from Tillamook Bay and Gold Beach located in Oregon.
However, should Americans be worried? WHOI notes that the detected radiation traces are very low and would not harm people.
"To put it in context, if you were to swim everyday for six hours a day in those waters for a year, that additional radiation from the addressed cesium from Japan ... is 1000 times smaller than one dental x-ray," said Ken Buesseler, a senior scientist at the WHOI, via USA Today. "In Japan, at its peak [cesium-134 levels] it was 10 million times higher than what we are seeing today on the West Coast."
Lookout for Godzilla!