California already has 12 radiation monitoring stations scattered around the state. The Environmental Protection Agency deployed more in the wake of what is going on in Japan. One installed at the top of a building by nuclear engineers at UC Berkeley is part science project for the students and part public service.
If or when any radioactive particles from Japan reach California, little plastic filters will tell scientists exactly what is floating in the air. One such filter was installed Wednesday on the roof of UC Berkeley's Department of Engineering building. Downstairs in the basement, nuclear engineers monitor the readings around the clock.
"We want to tell the public and you and everyone what radiation, if there is any, what radiation we have to deal with," Professor Kai Vetter said.
Scientists will know the air is from Japan if they find traces of radioactive isotopes like Cesium 137, which caused serious health damage after Chernobyl. Many experts say what is happening in Japan is nowhere near that level of disaster.
"It's probably more than a Three Mile Island, but much less than a Chernobyl," Dan Chivers, Ph.D, said.
Scientists do not expect any notable changes in radiation levels until Friday. Any radioactive particles from Japan would have to travel more than 5,100 miles to reach the Bay Area. Even if that happens, they predict the levels will be lower than what people are exposed to on a daily basis.
"It's much less still than a regular plane flight particularly if you go to the clinic and have an x-ray, that's much higher levels you will be exposed to," Vetter said.
The EPA's radiation monitors may be more high-tech than what is on UC Berkeley's rooftop, but they tell experts the same thing. One such monitor sits on top of the Bay Area Air Quality Management District offices in San Francisco's Western Addition.
"Words matter, the word 'plume' makes it sound really scary," U.S. Surgeon General Dr. Regina Benjamin said.
Speaking at UC Berkeley Thursday, Benjamin tried to calm fears.
"There's no reason to be afraid right now because the harmful levels are not heading in our direction," Benjamin said.
Scientists in Berkeley will get the first results Thursday evening, but they are not expected to say much. The real results will come Friday or the following day, when and if those particles from Japan may hit the West Coast.