Fukushima Dai-ichi Nuclear plant after earthquake and tsunami. (Photo: DigitalGlobe via Getty)

Click here for the UC Berkeley radiation monitoring site

Two weeks ago when we were all freaking out expressing concern about radiation from the ill-fated Fukushima nuclear power plant in Japan wafting our Bay-Area way via the Pacific Ocean, we posted these interviews with several scientists and health experts, all of whom assured us there was nothing to worry about, silly laypeople.

To which reader replies included this:

“Just show us actual Rad. Levels and we can make up our own minds. Show us real time hour by hour Rad Levels! not that i don’t trust you, Yes I don’t trust you.”

EE Cummingsesque capitalization aside, point taken on the transparency issue. So… radiation watchers take note: from today’s San Jose Mercury News:

Five thousand miles from Japan, UC Berkeley scientists don’t have to read the headlines to know what is happening at a crippled nuclear power plant. They just need to glimpse at their computer screens.

There, a steady stream of data from Berkeley’s air, rain and creekwater samples shows peaks and troughs of radioactive contamination — posing no threat to Californians’ health, but telling a tragic tale of Japan’s struggle to contain the threat.

“We can find out what’s going on just by looking at the radioisotope signatures,” said research scientist Daniel H. Chivers, sitting at a laptop in the dark basement of the university’s engineering building, where equipment for a routine class was quickly transformed after the accident into a sophisticated radiation detection system…

(T)he UC Berkeley team, led by nuclear engineering professor Kai Vetter, publishes its daily analysis on the department’s website.

Did someone say website?

On the UC Berkeley Nuclear Engineering air and rain water monitoring pages, you can see radiation data measured from samples collected on the roof of Etcheverry Hall on the UC Berkeley campus and read a narrative log of results.

The site contains a lot of information that’s not that easy to interpret. But this explanation should help:

In the table below the three plots, we are providing two numbers for each of the isotopes. The first is a standard concentration unit of Becquerel per liter (Bq/L) which describes the number of particles decaying over the period of one second in one liter. For the general public, we have converted this number to an exposure dose per liter of air breathed (or water consumed for the rain water measure). The number in parentheses is the number of years of breathing the air (or the number of liters of water consumed) that would be needed for a person to receive the radiation exposure of a single round trip flight from San Francisco to Washington D.C. (0.05 mSv).

So, for example, on the rain water page, scroll down to the last date on the chart, March 26, then look in the column for the isotope I-131 (Iodine 131). There, you’ll see in parentheses the number 728, which means you’d have to drink 728 liters of water containing that level of Iodine 131 to consume the same amount of radiation you’d be exposed to when flying in an airplane cross-country.

Meaning: We’re still a long way from dangerous, at least in these parts.

You can take heart — or not — from this quote:

“There is nothing of concern here,” Vetter said. “As long as Japan does not get another 9.0 earthquake “… there is no risk to California.”

“They do not pose long-term risk, so long as the Japan workers are able to shut it down eventually,” he said.

  • Gregg Williams

    Thanks for giving us the straight facts and an educated

  • John Luevano

    Yes…thank you for sending just the facts w/o all the hype…technology at it’s best!

  • Morehonestyplease

    This is misleading.

    The issue here is not comparing Iodine or Cesium to background radiation received during a flight. The issue is INGESTION.

    If you ingest that Iodine and/or Cesium, there is the possibility that you do not pass it and that you are then subject to CONTINUOUS exposure.

    According to the New York Academy of Sciences, more than 1,000,000 people died as a result of ingesting radioactive particles from Chernyobl.

    Please don’t be part of the sheep-leading media by telling us everything is ok. This is the USA, not the USSA. Stop giving us nuclear industry propaganda about “background radiation” and start talking about INGESTION.

    You know, they tell the same lies about ‘depleted’ uranium – the military says it is perfectly safe. Anyone who thinks that’s true needs to search google images for “babies in fallujah.”

    • http://www.nuc.berkeley.edu/UCBAirSampling Dan Chivers

      This seems misleading, but the fact is we are using the dose conversion factors for each nuclide which takes into account ingestion, uptake to various organs, and risk of mutation. This results in an “equivalent” dose which attempts to equalize the health risks of different types of exposures (internal and external). It is true that ingesting radio-iodine (thyroid risk) will be different than full body dose (e.g. x-ray or plane flight) in that the location of the organ at risk will be different. Please see our website for more details and take part in the forum. There is a wealth of information there and we try to give the hard numbers to allow the public a chance to gain some perspective. Please understand we have no vested interest other than maintaining the trust of the public and we intend to do this through transparency and honesty.

  • day lee

    can the rainwater harm us by getting on our skin, because I went out in the rain on wed the 23 and now my skin on my head face and arms feel irritated. I shaved my head with a razor that day before I went out in the rain with no umbrella.

    • Jon Brooks

      No nothing to worry about.

  • Heart69

    Heard that reactor 2 built on top of an aquifer completely melted down and is contaminating the ocean with plutonium and uranium, but hey just go back to bed, turn on Jersey Shore and don’t worry about it. More intense radiation coming our way California. It’s not OK and the Japanese and the US government isnt fixing or helping anything. If we as a people don’t start revolting now and demand or constitutional rights back we will be to sick to do so. Politicians are in bed with big corporations that are poisoning and raping the earth. We need change. do not take this any more…

  • Mary Lou

    What about the cumulative effects of many low-dose exposures over time? “You’d have to drink xxx liters of water . . . .” Yes, I expect I’ll be doing that, as will my grandchildren, IN ADDITION TO taking a flight or two. It isn’t a choice; it’s an addition. What’s the half-life of the radioactive iodine and cesium? When I die, if I’m cremated, will there be radioactive fallout? I’d hate that. I’m a lot less interested in being reassured than in being given the straight talk.

    • Jon Brooks

      According to Dan Chivers (2nd to last audio clip), the radiation at current levels will peter out over several months, which if true I believe means that you would never ingest cumulatively the amount equivalent to one cross-country flight; though I will ask him about the math on that.

      However, I should note that he also says in that clip that this only holds true as “long as we don’t have a breach of primary containment,” and so we should probably go back and ask him how the scenario changes if that does occur. Because that possibility has been talked about in the media over the last week.

  • AK

    Thank you for the information. However what I would like to understand is that; can we compare the radiation coming from Japan to the radiation that we get, for example from a dental X-ray, or a ride on airplane? Aren’t we just comparing apples and oranges, given the isotopes, and the fact that the radiation from Japan is the by-product of fission process in nuclear plants? I am not an expert, but I don’t believe that a fission process takes place in X-ray machines!!

    Thank you!


Jon Brooks

Jon Brooks is the host and editor for KQED's daily health and technology blog, Future of You. He is the former editor of KQED News Fix.

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