Radiation fears have prevented authorities from collecting as many as 1,000 bodies of victims of the March 11 earthquake and tsunami from within the 20-kilometer-radius evacuation zone around the stricken Fukushima nuclear plant, police sources said Thursday.
One of the sources said bodies had been ‘‘exposed to high levels of radiation after death.’’ The view was supported by the detection Sunday of elevated levels of radiation on a body found in Okuma, Fukushima Prefecture, about 5 km from the Fukushima Daiichi Nuclear Power Station.
The authorities are now considering how to collect the bodies, given fears that police officers, doctors and bereaved families may be exposed to radiation in retrieving the radiation-exposed bodies or at morgues, according to the sources.
They initially planned to inspect the bodies after transporting them outside the evacuation zone, but the plan is being reconsidered due to the concerns over exposure.
Local residents have been forced to leave the zone since the current nuclear crisis began unfolding at the Tokyo Electric Power Co plant, which is leaking radioactive materials as its cooling systems for its reactors and nuclear spent-fuel pools have been knocked out by the disaster.
Even after the bodies are handed over to the victims’ families, cremating them could spread plumes containing radioactive materials, while burying the victims could contaminate the soil around them, according to the sources.
The authorities are considering decontaminating and inspecting the bodies where they are found. But the sources said that cleansing decomposing bodies could damage them further.
Victims can be identified through DNA analysis of nail samples, but even then considerable time and effort must be taken to decontaminate the samples, according to experts.
Elevated levels of radiation detected on the victim in the town of Okuma last Sunday forced local police to give up on retrieving the body.
‘‘Measures that can be taken vary depending on the level of radiation, so there need to be professionals who can control radiation,’’ said an expert on treating people exposed to radiation. ‘‘One option is to take decontamination vehicles there and decontaminate the bodies one by one.’‘
Meanwhile, new readings show radiation levels continue to rise in the ocean outside the leaking nuclear plant, officials said Thursday, as they debated whether to broaden the evacuation zone around the tsunami-damaged facility.
Japan’s Nuclear and Industrial Safety Agency said it was looking into a report from the U.N. atomic agency about high levels of radiation in the village of Iitate, 40 kilometers from the plant in Fukushima prefecture.
The International Atomic Energy Agency said the level in one spot tested in Iitate was twice its suggested threshold for evacuation.
NISA spokesman Hidehiko Nishiyama said officials were checking radiation levels in the village, which lies outside even a voluntary evacuation area 30 kilometers from the plant. He said most residents have left, but about 100 have chosen to stay.
“We take it seriously,” he said Thursday. “We may consider asking these people to evacuate. But we need more time to study the situation.” People in a 20-kilometer radius around the plant have already been ordered to leave their homes.
Experts say the spike does not pose an immediate danger to human health, but evacuation recommendations tend to be conservative to prevent longterm exposure to any elevation in radiation levels.
Operations continued Thursday to cool down the dangerously overheated Fukushima Daiichi nuclear plant, which has leaked radiation after being damaged in the March 11 quake and tsunami.
The mission to stabilize the plant, 250 kilometers northeast of Tokyo, has become more complicated since the discovery a week ago that radioactive water is pooling inside, restricting the areas in which crews can work.
It also puts emergency crews in the uncomfortable position of having to pump in more water to continue cooling the reactor while simultaneously pumping out contaminated water.
French nuclear officials who are experts of the removal of such radiation have recently arrived to help out, and the IAEA is also sending experts. On Thursday, President Nicolas Sarkozy of France arrived in Tokyo on Thursday for talks with Prime Minister Naoto Kan.
Contamination from the plant has been seeping into the sea, posing no threat to human health because fishing and swimming aren’t allowed in the vicinity but sparking concern about the continued leaks, Nishiyama said.
However, radiation levels are rising. Seawater some 330 meters from the shore south of the plant measured 4,385 times the legal limit, up from 3,355 times the allowed amount the previous day, officials from plant operator Tokyo Electric Power Co said.
Experts say the radioactive particles are unlikely to build up significantly in fish, but the seafood concerns in the country that gave the world sushi are yet another blemish for Brand Japan.
Radioactive iodine is short-lived, with a half-life of just eight days, and in any case was expected to dissipate quickly in the vast Pacific Ocean. It does not tend to accumulate in shellfish.
Other radioactive particles have been detected in the waters near the plant, and some have made their way into fish. Trace amounts of radioactive cesium-137 have been found in anchovies as far afield as Chiba, near Tokyo, but at less than 1% of acceptable levels.
“We have repeatedly told consumers that it is perfectly safe to eat fish,” said Shoichi Takayama, an official with Japan’s fishery agency.
TEPCO, which owns the Fukushima plant, has come under growing criticism for its handling of the nuclear crisis. The nuclear safety agency ordered plant operators nationwide on Wednesday to review their emergency procedures. The agency told utilities they must have on hand mobile backup generators and fire engines, which have been used at Fukushima to cool the reactors.