Bay Area residents are not at risk of radiation contamination from a potential nuclear disaster in Japan, regional and federal authorities said Thursday.
Residents near the Fukushima Daiichi Nuclear Power Station in Japan have been evacuated since the plant was crippled by last week's deadly 9.0-magnitude earthquake and ensuing tsunami, and models show that a radioactive plume from the plant could reach California on Friday.
But Eric Stevenson, director of technical services for the Bay Area Air Quality Management District, said any risk to people on American soil is negligible.
The district operates a radiation detector for the Environmental Protection Agency at its San Francisco facility, and the detector has not reported elevated levels of radiation, Stevenson said.
"Everybody, for the most part, is saying the risks are insignificant," he said.
The EPA, Nuclear Regulatory Commission and U.S. Department of Health and Human Services have all said California residents are not expected to be at risk, according to the state Department of Public Health.
Japanese officials are working frantically to cool the plant's reactors, but Stevenson said that regardless of the magnitude of the crisis, it's unlikely harmful radiation will reach the U.S.
"It would have to be a major catastrophe for us to be significantly impacted," he said. "Most of these impacts will, unfortunately for the Japanese, be localized."
He pointed out that most of the impacts from the Chernobyl nuclear disaster were local, even though the facility didn't have a containment building and used graphite fuel that ignited and burned.
The burning allowed materials to be elevated into the atmosphere and dispersed, which would be necessary for the nuclear radiation to spread widely.
Still, the U.S. government has implemented several policies out of "an abundance of caution" to reassure and protect residents.
The EPA, whose California monitoring stations include locations in San Jose and Richmond, has set up additional stations in Guam, Alaska and Hawaii.
U.S. Customs and Border Protection has directed its employees to specifically monitor maritime and air traffic from Japan for possible radiation contamination.
So far no planes entering the U.S. have tested positive for harmful levels of radiation, and travelers are being observed for signs of radiation sickness, according to the agency.
Mail and cargo are also being tested, and anything that could be cause for alarm will be denied entry to the country, agency officials said.
The California Department of Public Health is advising residents not to take potassium iodide as a precautionary measure.
"It is not necessary given the current circumstances in Japan," department officials said in a statement.