Low levels of radiation detected in Idaho, pose no public health threat

Boise — Trace levels of radioactive iodine-131 (I-131) showing up in Idaho from Japan continues to pose no public health risks.

As expected, monitoring activities in and around the state have picked up very low levels of I-131 in air, drinking water, rainwater, and milk; however, the levels detected are far below levels of public health concern.

Low, but measurable, amounts of I-131 were first detected on March 21 in an air sample from a portable Environmental Protection Agency (EPA) radiation network (RadNet) monitor in Boise. Levels detected since then are declining and are expected to decline further as the situation at the Japanese nuclear facility is being brought under control.

Later monitoring in Boise, showed trace amounts of I-131 in precipitation as well as one municipal drinking water system that draw its water from the Boise River.

Due to detection of I-131 in this drinking water system, the Idaho Department of Environmental Quality (DEQ) is screening other municipal drinking water systems throughout the state that use surface water (rivers or lakes) as their source.

Monitoring by DEQ’s Idaho National Laboratory (INL) Oversight program has also detected the presence of I-131 in air and milk samples at minuscule levels, similar to those detected by EPA in other states.

DEQ’s INL Oversight program has routinely monitored for radiation in the air and milk from around the Department of Energy (DOE) facility near Idaho Falls since 1994.

"At no point have detected levels come close to levels of concern," said Mark Dietrich, DEQ’s Emergency Response Program Coordinator.

Idaho will continue to closely track radiation levels detected by the EPA RadNet monitors as well as our own INL Oversight radiation monitors. Due to the events in Japan, DEQ and other state agencies are working closely with EPA and other federal agencies to ensure Idaho citizens are kept informed of all monitoring results in the state.