Sunday, January 1, 2012


First of all, Happy New Year!  Just think, a year ago, the earth was in the same relative position to the sun as it is today.  (Of course, we could say that any day of the year and be completely accurate; there's nothing remarkable about 1 Jan astronomically speaking, though 22 Dec is pretty neat).
Today I wanted to talk about radiation.  There was a bit of an outcry during the Fukushima disaster, which triggered a lot of conversation and somewhat less thought on the topic, but what prompts this writing is something slightly more personal.  I have a friend who is considering taking a job at Holloman AFB, which is in Alamogordo, NM, and also happens to be the site of multiple atomic and nuclear weapons tests.  He has a child, and the idea of being raised near a potentially hot radioactive site is understandably problematic.
The first thing we should remember about radiation damage is that it's cumulative- it "metabolizes" very, very slowly, and can quickly build to toxic levels (Rads in the Fallout series are fairly accurate, if only in this respect.  In fact, I think I'll use the term).  Being exposed to 100 Rads all at once is only slightly more dangerous than being exposed to 10 Rads a day for 10 days.  And by Rads, I actually mean milli-Sieverts, or mSv.  Rads just sounds more... rad.
At Alamogordo, at the Trinity site, the radiation level at ground zero pings at about 10 times the background rate.  At first, that sounds threatening, but I wasn't sure what the background rate was- and it turns out, on average, the yearly consumption of Rads for anyone just living in our society is about 2.  So, if you camped out on ground zero at Alamogordo for a full year, you'd receive a cumulative dose of 20 Rads.
Still, this doesn't put things in perspective, and for that I came across a handy reference from the World Nuclear Association.  I won't reproduce it here, but there's also a good table here, down towards the bottom.
What I'd like to highlight are specifically the thresholds- after 100 Rads, over the course of a year, there's some increased chance of cancer.  It says it's about 5%.  To get this from Alamogordo, you'd have to camp out at ground zero for an entire year running chest x-rays twice a day, and even then you'd have a 95% chance of walking away with no ill effects (well, besides law enforcement constantly trying to stop you from trespassing, and the owner of the x-ray machine convinced you're trying to void his warranty).
50 Rads per year, for techs that work in the industry, is the legal limit for professional exposure, and there are no discernible effects on health at this level (they are as likely to be beneficial as not).
But that's just at ground zero.  Alamogordo is a healthy distance south, and the interesting thing is the fallout never reached it- the explosion carried north and west.
 Trinity Fallout Map
It's almost entirely certain to be safe to live in; as for being a place you'd want to live, well, you'll have to make up your own mind.  It is New Mexico, after all, and it's a small town, not unlike Altus, OK.
Finally, I'd like to end with a quote from the WNA linked to above.  Radiation is dangerous, but even more dangerous is the misunderstanding of radiation.  "In 1986 the Chernobyl nuclear accident caused a few (preventable) deaths from thyroid cancer and massive psycho-social impact due to relocation of over 100,000 people, mostly unnecessarily. (It also caused 28 to 47 deaths among clean-up workers who received high radiation exposure.) For members of the public, fear of radiation was much more devastating than radiation itself."

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