Radiation wafting toward the U.S. from stricken nuclear reactors in Japan presents less of a danger than 1950s-era atomic weapons testing or the 1986 Chernobyl accident, weather experts and government officials said yesterday.
The radiation plume from the reactors is moving northeast over the Pacific, the Austrian Meteorological and Geophysics Center reported on its website. Weather patterns over the ocean may bring it to the U.S. today, Jeff Masters, co-founder of Weather Underground Inc. in Ann Arbor, Michigan, said in a telephone interview.
Even in the worst-case scenario of a reactor meltdown at the Fukushima plant, dilution of the radiation by the Jet Stream and Pacific winds is likely to prevent harmful radiation from reaching the West Coast, said Thomas McKone, an adjunct professor in the Department of Environmental Health Sciences at the University of California, Berkeley.
“There is enormous dilution between Japan and here,” said McCone, who is also a senior staff scientist at the U.S. Energy Department’s Lawrence Berkeley National Laboratory. “I don’t think there can be any measurable health impacts in California.”
After Chernobyl, experts found no measurable health effects to humans from direct radiation exposure outside of a 50-mile radius, according to McKone. Bombs tested in the U.S. in the 1950s and 1960s released much more radiation than is coming from the Fukushima plant, crippled by Japan’s largest earthquake on record and the resulting tsunami, Masters said.
“It is hard to compare a bomb going off up in the air over Nevada with something 5,000 miles away in Japan at the surface,” Masters said. “The exposure was far, far greater from the Nevada test explosions.”
More than 500 atmospheric nuclear weapons tests were conducted worldwide prior to 1963, according to the U.S. Centers for Disease Control. The U.S. government, in a study that included the CDC and the National Cancer Institute, estimated in 2006 that anyone living in the lower 48 states after 1951 had been exposed to some fallout.
About 50 deaths have been directly attributed to radiation from Chernobyl, while 4,000 may eventually die from the side effects of exposure, mostly from cancer or related disease, according to a 2005 World Health Organization report.
President Barack Obama said the U.S. faces no danger of radioactive contamination from the crippled Japanese nuclear plant and he has ordered a “comprehensive review” of safety at U.S. facilities.
Particles in Plume
The Nuclear Regulatory Commission has studied U.S. plants and they have been “declared safe for any number of extreme contingencies,” Obama said at the White House. Still, he said, a review should be conducted based on what is learned from the damage at the Japanese facility.
Radiation particles released into the air from the Japanese reactor vessels and spent-fuel ponds are moving southeast before extending in a northeasterly pattern over the Pacific. Particles may start moving northwest as the winds are expected to shift.
Radioactive barium, cesium, iodine and tellurium have been detected in the plume, the Austrian agency said yesterday. A partially dispersed cloud passed through the Tokyo area on March 16, according to the Austrian center.
“Whether it will be even detectable” when it arrives in the U.S. “is a question in my mind because of the amount of dispersion that goes on over at least a 5,000-mile track that that stuff had to take,” said Masters. “It just wasn’t emitted in large enough quantities to be a threat to human health and it may not even be detectable.”
No Health Issues
California Governor Jerry Brown said the state is monitoring the situation. His spokeswoman, Elizabeth Ashford, said that “at this point, there is no risk to California from radiation.”
No radiation had been detected yesterday along the U.S. West Coast and it is not known if or when it might reach California, Howard Backer, interim director of the California Department of Public Health, said yesterday during a call with reporters.
“We don’t anticipate any amount of radiation that will cause health effects,” Backer said. The plume from Japan will be dispersed to the point where it may be difficult to distinguish from normal background radiation sources, he said.
Radiation levels in the state may rise although not to a degree that would pose a threat to public health, Jonathan Fielding, director of public health of Los Angeles County, said during the press event.
That hasn’t stopped fear from spreading, said Kirk Smith, a professor at the University of California School of Public Health at Berkeley who has studied the fallout from Chernobyl and the health risks of radiation.
Smith said some of his students have discussed moving to Denver to get away from fallout, unaware that exposure to naturally occurring daily radiation is higher in mountainous Colorado than at sea level in California.
“The radiation you get on a flight to Denver would be far higher than anything that could come from Japan,” Smith said.
San Francisco residents have rushed to stores to buy potassium iodide pills, which can protect against radiation exposure, said Eileen Shields, a spokeswoman for the city Public Health Department.
“People are wasting their money and there is no reason to do it because there is no radiation level sufficient to merit this,” Shields said. The Johns Hopkins Office of Critical Event Preparedness and Response warned that the drug may have serious side effects for people with certain allergies and kidney and thyroid problems.
The state of California and Los Angeles County may put up additional radiation monitors to assess the situation, said Chris Ipsen, division chief for the city of Los Angeles’s emergency management department.
The best chance to detect the radiation in California may come next week when the plume mixes with storm systems coming ashore along the coast, said Masters, who before founding Weather Underground tracked acid rain and air pollution.
“That would be the most likely time for it to get to the ground and be detectable,” Masters said. “But again, the amounts are going to be pretty darn small.”
Tracking a plume isn’t an exact science, said Sue Haupt, scientific program manager at the National Center for Atmospheric Research in Boulder, Colorado, and a meteorology professor and researcher at Pennsylvania State University.
The mapping requires computer models, and variables include the height of the release as well as the weather patterns it encounters.
Weather over the Pacific can be complicated, said Jim Andrews, a senior forecaster for AccuWeather Inc. in State College, Pennsylvania.
The Jet Stream is always dipping and buckling, so anything being carried on the wind could be blown over a wide area. In addition, winds at different levels of the atmosphere blow in different directions, which may shear apart a cloud of radiation, he said.
“Certainly the weather is going to play a large factor, otherwise the size of the particle will dictate how long it is going to take to settle” to the surface, said David Stauffer, a meteorology professor at Penn State. “The larger ones will fall out quicker than the smaller ones.”
While plumes of radiation linked to the Chernobyl explosion were detected all over the world, the amount at places such as Hawaii was less than the radiation exposure from a chest X-ray, Smith said.
“Radiation is odd, and it has this terrible history of being born in secrecy and war,” Smith said. “We are capable of measuring extremely small amounts, but just because you can measure it doesn’t mean it’s dangerous.”