BOISE -- Idaho Department of Environmental Quality officials say trace radiation levels in Idaho from Japan are declining and expected to drop even more in coming weeks.
Low, but measurable, radioactive iodine-131 levels were first detected March 21 in an air sample from a portable radiation network monitor in Boise.
Officials say small amounts that pose no health risk continue to show up in rainwater, drinking water and air, but are diminishing.
Radioactive fallout from Japan has been reported in seven states, including Washington and California, since the March 11 earthquake and tsunami damaged the Fukushima Dai-ichi nuclear plant.
DEQ Emergency Response Coordinator Mark Dietrich says at no point have detected levels come close to amounts that merit a public health concern.