Two days ago we put up a post about a UC Berkeley Nuclear Engineering web site at which you can find radiation data measured from samples collected on the roof of Etcheverry Hall on the UC Berkeley campus, as well as read a narrative log of results.

That post has proved very popular, with people finding it via search terms like “radiation levels in california,” “california radiation levels,” “bay area radiation,” “japan california radiation,” and “justin bieber” (I keyworded that just to lure in more people. Ha ha just kidding.)

Anyway, it’s pretty clear that people are still concerned about the inter-continental radiation catching the Pacific jetstream for a free ride over to our neck of the woods.

Concerned, understandably. I mean, I don’t know the difference between a becquerel of Cesium-134 and a pint of ice cream, do you? And when it comes to radiation, ignorance is not bliss.

So for further clarification, we interviewed Dan Chivers, a research scientist in the UC Berkeley Department of Engineering, which maintains the radiation data web site. In the interview, Chivers recapitulated the meaning of the data posted by his lab, stressing the negligible amount of radiation that has been measured to date.

Just one comparison made on the site: It would take 487 years of breathing air that contains the amount of Iodine-131 the lab measured on one particular day to equal the amount that an individual is exposed to on a single cross-country round-trip in an airplane.

Listen below, and note that KQED’s Cy Musiker will be talking to Dan Chivers today at 5:30 p.m. on the radio. Listen here.

Dan Chivers says the amount of radiation measured in Berkeley is not detrimental to health[audio:]

Comparisons of radiation measured to amount received from other common sources deemed safe[audio:]

Chivers explains the web site chart[audio:]

How the Japan accident is different from Chernobyl[audio:]

The amount of radiation we’re receiving is not cumulative[audio:]

Explanation of the web site[audio:]

The radiation we’re receiving will peter our provided the Japan plant core is not breached [audio:]

The trends in the radiation measured[audio:]

  • JP

    Thanks for the thorough report. I have heard that sheep and goat milk concentrate radiation as much as 10x more than cows milk. I am wondering if cheese from these milks would further concentrate any of the isotopes. Thank you for staying with this story and any updates.

  • has anyone been checking the beer and hard liquor alcohol radiation levels..I go through a 6 pack a day sometimes and I’m starting to get a little worried.

    • Jon Brooks

      You’re worried even after a 6-pack?


Jon Brooks

Jon Brooks is the host and editor of KQED’s health and technology blog, Future of You. He is the former editor of KQED’s daily news blog, News Fix. A veteran blogger, he previously worked for Yahoo! in various news writing and editing roles. He was also the editor of, which documented user-generated content about the financial crisis and recession. Jon is also a playwright whose work has been produced in San Francisco, New York, Italy, and around the U.S. He has written about film for his own blog and studied film at Boston University. He has an MFA in Creative Writing from Brooklyn College.

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