As federal and state officials continued Wednesday to issue assurances that there was little risk to public health in North America from the nuclear crisis in Japan, the EPA announced it was stepping up its monitoring capability in Alaska, Hawaii and Guam.
Three deployable monitors will be placed in Alaska to broaden the EPA's fixed station coverage already in place in Anchorage, Fairbanks and Juneau. State officials who assist the EPA with that equipment say they haven't detected any elevated radiation from the crippled reactors and spent-fuel storage facilities.
Naturally occurring uranium, radium, radon and other radioactive elements in local dust and the air, along with gamma radiation from the sun and interstellar space, generate a normal range of background readings on the monitors, said Bernd Jilly, laboratory director for the state health department. As a general rule, public health officials get concerned if those levels rise to 40 times the normal high-end background level, he said. So far, readings on the Anchorage monitor, stationed on a building roof near Midtown, are within normal range, he said.
"We are continually monitoring the air in Anchorage," Jilly said. "If there is any significant increase in the amount of radiation we will certainly effect notifying our partners and activating the whole cascade of emergency response. Until that happens, everything is running normally and we are examining our data a couple times a day just to make sure we're ahead of the curve."
The EPA announcement of the additional monitors set off some confusion, since it said one of the deployable monitors would be placed in Juneau. The state Department of Environmental Conservation already manages a fixed monitor in Juneau on behalf of the EPA, said DEC spokesman Ty Keltner. While technicians had been adjusting the Juneau device in recent weeks, it's functioning properly, he said.
Some officials think a better location for the portable unit would be Ketchikan, based on prevailing wind patterns and to ensure as broad a coverage as possible, Keltner said.
The other two new locations were Nome and Dutch Harbor. The EPA said two additional monitors would be placed in Hawaii and another two in Guam. About 100 fixed monitors are in place around the country in a network the EPA calls RadNet.
In a telephone news conference Wednesday with reporters from Alaska and the Pacific Northwest, Jonathan Edwards, director of the EPA's radiation protection division in Washington, D.C., said data from those monitors are continually monitored via satellite at an agency lab in Alabama.
In addition to the constant satellite feed, local technicians remove filters from the devices twice a week and send them to Alabama for analysis. That's because the monitors can only tell whether there is radiation, not its sources. Dust particles of uranium, iodine, cesium and other radioactive isotopes can be captured in the filters and identified through analysis, Edwards said.
A spike in radiation at one of the monitors would set off an alarm in Alabama, Edwards said. If a technician determined the equipment was working properly, the alarm would be relayed to federal and state emergency response officials, he said.
Prevailing winds and ocean currents generally travel toward the Pacific Northwest and southern Alaska from Japan. It would take several days for particles to cross the Pacific, he said.
But the news conference also revealed the fragmentation of responsibilities in the current emergency. Asked several times for his assessment of the risk to the United States, Edwards would only quote the Nuclear Regulatory Commission.
"As the Nuclear Regulatory Commission has stated, we do not expect harmful levels to get to the U.S. and certainly not anticipating anything beyond our normal background radiations that we see in our fixed network," Edwards said.
As for the risks to the ocean and to seafood, he deferred to the National Oceanic and Atmospheric Administration and the Food and Drug Administration, while he said the Department of Energy had the task of providing information on the Japanese reactors themselves.
The state, meanwhile, is attempting to make its own assurances. Keltner of the DEC said the state has issued a statement saying Alaska's fish continues to be safe, even though no one from the state is monitoring either the fish themselves or the ocean for radiation.
Keltner said the governor's office got involved in that statement because of reports in Europe that Alaska cod was somehow getting contaminated with radiation.
Keltner said the Japanese crisis hasn't yet presented a threat that would require monitoring fish for radiation.
While government officials say there is a margin of safety before an alarm is triggered, some other experts say that any increase over background radiation is undesirable and could lead to additional medical problems, especially in the long term and especially for children.
One product of nuclear fission, whether from a nuclear reactor or an atomic bomb, is strontium 90, which mimics calcium chemically and is absorbed in bones. There, over a half-life of 30 years, it undergoes atomic decay, releasing radiation. Concern about cancers and leukemia from strontium 90 fallout from atmospheric nuclear tests led to the 1963 test ban treaty.
A much shorter lived isotope, iodine 131, with a halflife of 8 days, is absorbed by the thyroid and has been blamed for thyroid cancers among residents who lived near the Chernobyl reactor.