Updated after the jump: L.A. Mayor Antonio Villaraigosa weighs in with much of the same.
The worst thing about radioactive clouds headed our way from Japan tomorrow?
Panic, says L.A. County Public Heath chief Jonathan Fielding.
"The biggest health impact is the psychological impact," he told reporters today. "We've had many many calls of people who are very concerned ... A lot of people are overreacting out of fear."
People need a chill pill, not potassium iodide, which can prevent thyroid cancer in the event of serious radiation.
But that's not what we'll see, state public health officials said Thursday. The order of the day was that y'all need to mellow out about possible radioactive weather reaching the West Coast from Japan tomorrow.
"The best estimate of whether radiation will reach our shores indicates that if they do the amount will be so small as to be the equivalent of our background normal radiation sources," says Howard Backer, interim director of the state Department of Public Health.
"We don't anticipate any amount of radiation that will cause any health effects," he said.
Even in a worst case scenario -- we presume this to mean total meltdown, or damn near close, at the Fukushima Daiichi Nuclear Power Station -- "there is no threat to public health in California," said Mike Dayton, acting secretary of the California Emergency Management Agency.
The state has radiation monitoring stations set up in L.A. and San Deigo, and L.A. county also monitors radiation levels.
Public health officials want Angelenos to take the crisis in Japan as an occasion to get prepared for the "big one" here.
"Go out and buy three to five days of food and water," said Backer.
Update: Late Thursday afternoon L.A. Mayor Antonio Villaraigosa issued a statement that reads, in part:
I would like to assure all Angelenos that despite the emerging nuclear situation in Japan, there is no immediate radiation threat to Los Angeles.
... Our thoughts and prayers remain with the people of Japan during this heart-breaking time.
First posted at 2:43 p.m.