We are continuing to monitor food, plants, seaweed for radioactivity from Fukushima Daiichi at our California lab. We are upgrading equipment, refining our methods, learning a lot. Right now any Cesium from Fukushima Daiichi is at levels too low for our equipment to detect. Weʻll be reporting more on the equipment and techniques we are using. The basic information is that we are using 3 inch by 3 inch Sodium Iodide detectors, which have pretty high sensitivity when you put enough lead around them to shield out background radiation.
We reported earlier that Dr. Ken Buesselerʻs project is reporting the detection of some Cesium 134 from Fukushima off the coast of Northern California. The level reported is 2 becquerel per cubic meter of water. A cubic meter of water, for those of you who havenʻt converted to metric yet, is a cube with dimensions of about 3.3 by 3.3 by 3.3 feet. To visualize 2 bq per cubic meter imagine random flashes of light in an area of that size, at the rate of approximately 2 per second (which is about 120 per minute). The fact that we have lived with radioactive cesium in the ocean since nuclear weapons were first tested in the atmosphere in the 1940ʻs does not give a lot of comfort to those of us who love the oceans. But we still need to see it in perspective, and the levels are still relatively low.
Iʻve been thinking a lot about my earlier post about the radioactive sand at Surfer Beach, Half Moon Bay, CA. I did determine to my satisfaction that the radiation was not from Fukushima Daiichi. The State of California and others agreed with me and said it was safe. While I still think it is a beautiful beach and that the radioactive minerals there are likely naturally occurring, I think making a blanket statement that it is safe is going a little farther than I am comfortable with. I provide radiation detection instruments to many safety professionals who work to meet regulatory compliance in the petroleum drilling and transportation industries. The sand on Surfer Beach contains the same NORM class materials that they have safety programs related to, and exceeds the levels deemed of concern by some States and by the EPA. Both Radium 226 and Thorium 232 emit alpha radiation, which can be hazardous inside the body if these radionuclides are ingested or inhaled. So people with babies and small children might want to think about whether that is the best beach to play on. If you want to find out more google NORM, Thorium 232, Radium 226. There is a lot of interesting information out there. I did feel a sense of urgency to let people know the radiation on that beach wasnʻt from Fukushima – because people were getting a little crazy over a false rumor.
Back to rumors again, there have been some reports of high radiation levels on beta sensors in the EPA Radnet network. I have tried to get information on what is happening by going to the source: The EPA. I wish I could report anything useful. I tried emailing them using email links on the Radnet website. None of the links were functional. I called EPA on the 2 phone numbers on their website on Dec. 17 2014. Iʻm still waiting for a return phone call. With response time like this, I hope we donʻt have a genuine emergency. I am continuing to investigate and will report here if I find out anything about what is going on.