TOKYO — With minor levels of excess radiation detected in Tokyo and at two nearby U.S. military bases, alarm is building among Americans in Japan who fear the Japanese government and the U.S. military are underplaying the threat of contamination from four out-of-control nuclear reactors.
The commander of U.S. Naval Forces in Japan, Rear Adm. Richard Wren, raised anxiety levels Tuesday when he advised residents of Yokosuka Naval Base, near Tokyo, to "limit outdoor activity" — less than a day after he told a town hall meeting that radiation from the reactors wouldn't affect them.
At Yokota Air Base, the largest U.S. base on Japan's mainland, testing of the air for contamination has gone from twice a day to hourly. The U.S. Navy said it was repositioning some ships, including the USS Essex, an amphibious assault vessel, from the east coast to the west coast of Japan's Honshu island because of contamination concerns.
U.S. helicopter crews supporting Japan's post-tsunami search-and-rescue efforts have been found with elevated — although not serious — radiation levels.
Never miss a local story.
The rising anxiety came after four days during which the 38,000 U.S. military personnel living in Japan, along with 43,000 family members, believed they had escaped unscathed from the 9.0-point quake and the tsunamis that ravaged Japan's northeast coast on Friday. U.S. military installations were undamaged and American bases were well outside the evacuation zone around that Japanese authorities declared around the Fukushima Dai-Ichi Nuclear Power Plant.
Then, on Tuesday, the Navy reported "very low levels of radioactivity from our sensitive instrumentation" at two bases, Yokosuka and Atsugi Naval Air Facility, amid a flurry of more bad news from Fukushima Daiichi, where four of six reactors have been compromised.
An explosion very late Monday — the third at the complex since the earthquake and tsunami — in Unit 2 may have damaged cooling system, as well as the unit's nuclear core, according to information Japan provided to the U.N.'s International Atomic Energy Agency. Spent nuclear fuel caught fire in Unit 4, releasing high levels of radiation.
Early Wednesday, another fire was reported at Unit 4.
Doubts came to the fore. Base residents wrote about them on Facebook and raised them in forums. Would they need iodine pills to ward off radiation if the contamination level rises? How much time would they have if they had to evacuate? What would they do with their pets?
Pregnant women, in particular, wondered whether they could still trust the military to keep them safe and meet their medical needs.
The Obama administration, much of whose information on the nuclear crisis comes from the Japanese government, strongly endorsed Japan's response, including the evacuation of those living within 12.4 miles of the Fukushima reactors and a call for those living as far as 18.6 miles away to remain indoors.
The U.S. Nuclear Regulatory Commission said the Japanese actions "parallel those the United States would suggest in a similar situation," and White House press secretary Jay Carney said the U.S. government was not recommending that its citizens leave Japan.
But private nuclear experts questioned the Japanese response, saying the suggestion that people could be protected by staying in place showed that the Japanese government did not appreciate the seriousness of the disaster.
Edwin Lyman, a physicist with the liberal Union of Concerned Scientists, said the recommendation to stay indoors, the effectiveness of which is dependent on the condition of the structure, showed Japan's "too complacent view." He also labeled Japan's release of information to the public as "erratic."
Others complained that the U.S. was not being aggressive enough in warning U.S. citizens here of the risks. While the State Department on Sunday urged U.S. citizens to avoid travel to Japan, other countries have gone farther. France has advised its citizens in the Tokyo area to leave, while Austria has temporarily relocated its embassy from the capital to the city of Osaka.
The respected Institute for Science and International Security said that with an explosion early Tuesday in Fukushima's Unit 2 reactor, the situation has "worsened considerably," and should be considered a Level 6 event on a scale of 1 to 7.
"A level 6 event means that consequences are broader and countermeasures are needed to deal with the radioactive contamination," Washington-based ISIS said.
Testing at Yokosuka and Atsugi Naval Air station revealed 0.5 millirems of radiation. The U.S. would evacuate at levels of 5,000 millirems or above, a military official said. Another said 12 hours of the additional radiation exposure at Yokosuka amounted to "less than one month's exposure to naturally occurring radiation that one would get from the sun, the earth or rocks."
Tokyo authorities said the radiation detected in the city was also very low and did not pose a risk to human health.
But anxiety remained high for many Americans. At Yokota Air Base, one woman told a public meeting Monday that she worried about having a medical emergency in the middle of a power blackout. Could medics get her out of her apartment tower if the elevators weren't working? Would her phone even work to call an ambulance?
A pregnant woman at Yokota told an online forum that she felt trapped and didn't like having decisions about her health in the hands of the military. "Even if I wanted to leave here on my own, I couldn't because technically I am not allowed to fly," she said.
Anxiety also was rising among American civilians elsewhere. Chris Wells, an American attorney who lives on the 21st floor of a Tokyo apartment tower, said he'd sent his pregnant wife and their 2-year-old child to Shanghai, and that he planned to leave on a flight to Honolulu.
He also said he'd prepared a contingency plan.
"I've put a bunch of food in the lower level parking area," he said. "I have food and water for at least a week. If I had accurate radiation warnings, I'd go down there and live."
(Ruskin, a McClatchy special correspondent, reported from Tokyo. Strobel reported from Washington.)
MORE FROM MCCLATCHY