Thursday, March 31, 2011

Over Here

Gamma ray spectra of particles in Seattle's air 
The spread of radiation continues with parts of Japan outside the evacuation zone recording radiation levels higher than the levels found around Chernobyl in regions Soviets deemed uninhabitable.  This situation may become clearer in the next few days.  Close to the Fukushima plant there is very little reliable information on radiation levels but farther away we have some very comprehensive coverage, including:

Live updates to radation levels from around Japan:

(Here's a similar map: courtesy former SFSU student Joey F.   He survived the quake in northern Japan, and luckily lives on the west coast where the tsunami impact was minimal. )

NY times has a map of the radiation and several other maps regarding the quake:

An article in New Scientist says that the amount of Cesium released now rivals that released by Chernobyl.    Which leads  to the question for us here in the US (especially here on the West Coast of the US): what are the long term health risks, Over Here?

The first step is to measure the radiation levels here as best we can.   This site has the IAEA's forecast for spread of Cs-137 (scroll down to see a global map):

Meanwhile testing of samples on the west coast is ongoing.   At my home institution, San Francisco State, Daniel C. is using a geiger counter to measure radiation levels at the air intake for Thornton Hall.    He's been able to record the number of decays per unit time and had noticed some variation depending on how much rain we get.  More information can be provided if one examines the gamma ray spectrum of the sources, because certain elements give off gamma rays of characteristic energies when they decay.
The figure above comes from an article discussed here in which UW researchers/students detected several isotopes, most noticably I-131 from the disaster in Japan. A similar project is underway at U.C. Berkeley:

I just learned from my friend Josh that radiation has now been detected in milk in Washington AND California.  The levels of I-131 are extremely low, so no need to panic yet.  But I am glad that I've been feeding my family and myself high levels of non-radioactive Iodine-rich healthy food (eg. yogurt, seaweed, plus bananas for Potassium).   One note of caution in interpreting news media stories:

 I just learned  from this interview with Dr. Helen Caldicott: that the descriptions of radiation given in the press as "equal to one chest X-ray" are meaningless and deceiving if we are talking about radioactive matter getting into the body.   Medical X-rays come from the outside and do not concentrate anywhere in the body.  But Iodine concentrates in the thyroid gland and I-131 was responsible for hundreds if not thousands of cancers at spite of its short half life!  Another example: the skin does a great job of stopping Alpha particles, however if an Alpha emitting source (with a short half life) is ingested the results can be fatal, as shown in the murder of a Russian Ex-KGB spy with Polonium 210, an Alpha emitter.


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