SUNDAY, March 13 (HealthDay News) -- The crisis at
earthquake-ravaged Japan's Fukushima Dai-ichi nuclear complex
continued to worsen Sunday, as government officials acknowledged
the threat of multiple meltdowns at the site's three reactors, and
more than 200,000 people were evacuated from the area to avoid
radiation contamination, according to news reports.
It was likely that a partial meltdown was already occurring at
one of the reactors, a top government official acknowledged, and
workers at the plant were struggling to keep temperatures down at
the other two reactors, the
Associated Press reported.
Chief Cabinet Secretary Yukio Edano said Sunday that it was
possible a hydrogen explosion could occur at one of the nuclear
complex's reactors -- the reactor that could be melting down. On
Saturday, an explosion occurred at the site's so-called Unit 1, as
operators tried to prevent a meltdown by flooding it with sea
A "meltdown" isn't a technical term, but instead a layman's
description of a serious collapse of a power plant's systems and
ability to control temperatures, the news service reported.
"At the risk of raising further public concern, we cannot rule out the possibility of an explosion," Edano said. "If there is an explosion, however, there would be no significant impact on human health."
Although more than 200,000 people had been evacuated from the
area as a precaution, Edano said the radioactivity released into
the environment so far was small and didn't pose any health
A complete meltdown could release uranium and dangerous
contaminants into the environment and pose major, widespread health
risks, the news service said.
Almost any increase in released radiation can raise long-term
cancer rates, and authorities were planning to distribute iodine to
residents in the area, according to the International Atomic Energy
Agency. Iodine counteracts the effects of radiation, the
As many as 160 people, including 60 elderly patients and medical
staff who had been waiting for evacuation in the nearby town of
Futabe, and 100 others evacuating by bus, might have been exposed
to radiation, said Ryo Miyake, a spokesman for Japan's nuclear
agency. The extent of their exposure -- or whether it had reached
dangerous levels -- was not clear. They were being taken to
On Saturday, an explosion destroyed the exterior walls of the
building that enveloped one of the site's reactors, but not the
actual metal housing encasing the reactor, Edano, the government
spokesman said, the
The nuclear plant was damaged by Friday's devastating earthquake
and tsunami that pounded Japan's northeastern coast. At least 1,800
people were killed and hundreds were missing, according to
government officials. But police in one of the hardest-hit areas
said the death toll there alone could eventually top 10,000, the
Radiation expert Jacqueline Williams, a research professor in
the department of radiation oncology at the University of Rochester
in New York, said depending on the type of explosion at the reactor
site, there could be a radiation risk to those at the plant.
"Anybody who is going in will be exposed to radiation -- and it will be whole-body," she said. "That's where you can get a lot of injuries to emergency personnel and maintenance personnel, depending on the degree of protection they go in with," she added.
High levels of radiation can be lethal because "radiation
disrupts your cells and you die," she said.
The danger to people outside the immediate area could come from
inhaling radioactive particles, Williams said. The type of
radiation released into the air depends on the type of fuel used at
a plant, she added.
Often the big components of released radiation are radioactive
iodine and radioactive cesium, Williams said.
Breathing in or eating food contaminated with radioactive iodine
can cause thyroid cancer. Food can become contaminated as the
radioactive dust settles on crops and even grass that cows or other
animals eat, she explained.
Radioactive cesium can cause more damage long-term, including
cancer and lung problems, Williams said.
How far the radioactivity might spread would depend on weather
conditions such as wind and rain, Williams said. These factors also
need to be taken into account when deciding how far to move people
from potential danger.
"The best protection from radiation is to get inside," she said. "Get something between you and the radiation."
In addition, all food should be washed and people should avoid
any contaminated milk and meat. Radiation can also affect the water
supply, Williams said.
"If it affects the water supply, then you are in more serious trouble," she said.
In Tokyo late Saturday afternoon, word of the explosion prompted
people to hoard supplies of bottled water, the
Washington Post reported.
"I saw a chain letter e-mail from my friend telling about the explosion in Fukushima," said one shopper who, as is the custom, wanted only to give his first name, Masahito. "Right now they're saying it's a nuclear accident. I have been trying to buy enough water for one week, just in case, but I can't find it anywhere. I've already been to four places, including a supermarket."
Williams noted that Japan relies on nuclear power for much of
its energy needs, since it has no natural power resources. "But
they are in an earthquake-prone area, and they have nuclear power
stations where they shouldn't be," she said.
For more on the health risks of nuclear radiation, visit the
University of Pittsburgh.