Japan’s prime minister Naoto Kan has warned radiation levels near the plant, about 250 kilometres north-east of Tokyo, are now harmful to human health. Radiation experts say staying indoors is the best way to limit exposure, and that it is useless to wear a face mask.
“Please do not go outside. Please stay indoors. Please close windows and make your homes airtight. Don’t turn on ventilators. Please hang your laundry indoors,” Chief Cabinet Secretary Edano said to the residents in the danger zone.
The International Atomic Energy Agency (IAEA) says radiation levels around the plant are now 400 millisieverts an hour, eight times the amount, every 60 minutes, that nuclear workers are normally supposed to absorb in a year.
According to the Associated Press, about 140,000 people were impacted by the warning.
Ira Helfand, a medical doctor based in Washington DC who has written extensively on the impacts of radiation, says someone exposed to this level of radiation for a couple of hours would develop radiation sickness.
He says there are two different types of harm caused by exposure to radiation.
“If you get a high enough dose of total body radiation you’ll develop something called radiation sickness and you – over the course of a period of days to weeks – develop nausea, vomiting, suppression of your bone marrow,” he said.
“Which allows you to become susceptible to infections, which promotes bleeding and you become weak, dehydrated.
“If you absorb a large enough dose you die from this over a period of several weeks.
“But even if you don’t get that kind of large total body dose of radiation, if you inhale or ingest radioactive nuclei like radio-iodine or caesium or strontium or plutonium you can develop cancer subsequently.
“This is a second distinct danger that people will be facing if there is a very large release of radiation in this disaster.”
The Japanese government continues to test the nearly 180,000 people evacuated from around the Fukushima plant for exposure to radiation.
Medical teams wearing white suits used Geiger counters and silver hand-held scanners to check everyone, aiming the scanners at little children holding their hands out.
Radiation detected by U.S. helicopters flying 60 miles from the Japanese shore Sunday prompted the repositioning of the USS Ronald Reagan and seven other U.S. Navy ships, military officials said.