A “minuscule” amount of radiation that probably came from damaged nuclear reactors in Japan was picked up at a California monitoring station yesterday, the U.S. government said.
The level of radiation registered in Sacramento was about “one-millionth of the dose” a person gets from rocks, bricks, the sun and natural background sources and “poses no concern,” the U.S. Environmental Protection Agency and Energy Department said in a joint statement.
A similar level of the radioactive isotope, xenon-133, was detected in Washington state on March 16 and 17, according to the agencies. It was “consistent with a release from the Fukushima reactors in Northern Japan,” according to the statement. The EPA and Energy Department have monitoring systems and neither found “radiation levels of concern.”
Japan is seeking to avert a meltdown at the Fukushima Dai-Ichi plant, which was damaged by a March 11 earthquake and tsunami. Helicopters and fire trucks used water buckets and cannons to help cool the plant, which has been crippled by explosions, fires and radiation leaks.
Tokyo Electric Power Co., the plant’s owner, said it’s also trying to connect a power line to the site to restart water pumps used to keep fuel rods from overheating.
President Barack Obama said yesterday his nuclear advisers don’t expect “harmful levels” of radiation will reach the U.S.
Aircraft and ships can operate into Japan’s airports and sea ports, excluding those damaged by the tsunami, the International Civil Aviation Organization said, citing information from the World Health Organization and other international agencies.
Screening for radiation of international passengers from Japan isn’t considered necessary at this time, the organization said in an e-mailed statement yesterday.
“The radiation is actually at a rather low altitude, less than a kilometer, rather than up high,” the U.S. Nuclear Regulatory Commission said yesterday in an e-mail. “It is bleeding out, carried on plumes of heat, and radiation levels drop off rapidly higher above the plant.”
California Governor Jerry Brown said the Japan crisis poses “no threat” to the state’s residents, and officials are monitoring air quality and consulting with federal agencies.
Doctors and scientists have said the Fukushima plant is unlikely to pose a health risk for people living more than 36 miles (50 kilometers) from the site.
The containment devices in Japan, even if compromised, offer more protection than reactors at the world’s worst nuclear disaster at Chernobyl, Ukraine, in 1986, said Donald Bucklin, former medical director of Palo Verde Nuclear Generating Station in Arizona, the largest U.S. nuclear plant.
Radiation can damage DNA, the building blocks of human life, said Bucklin, now medical review officer for U.S. HealthWorks, the nation’s largest private provider of occupational health care. While the body repairs most damage, some radiation-caused mutations can make cells malignant, he said.
Radiation spewed from the reactor in a meltdown might rise to as high as 500 meters (1,640 feet), and is unlikely to reach Tokyo, 135 miles away, John Beddington, U.K’s chief science officer, said on a conference call March 16 with the British Embassy in Tokyo. The Chernobyl explosion sent radioactive dust 30,000 feet high and continued for months.
The public-health risk would be equal to little more than two additional chest x-rays, said John Lee, a professor of nuclear engineering and radiological sciences, at the University of Michigan in Ann Arbor. A Chernobyl type of explosion is impossible, he said.