Calculating your own natural radiation dose in context

26 06 2012

 

Traditional Radiation Trefoil Hazard Symbol. (Image credit: ORAU)

A Dose of Radiation Information

How much radiation is normal?

In light of Fukushima, sensationalized media, political fear-stoking, and rampant misinformation regarding radioactivity, consider this post an easy-to-reference tool/resource.  With it, you can be armed to understand and quickly make sense of this over-mystified, natural aspect of reality when it comes up.

For starters, here’s the simple reality about how much radiation you receive in a year just for standing on Planet Earth:

The average natural annual radiation dose for a U.S. resident is about 300 millirem, and when including man-made commercial products and medical procedures (MRI scans, etc.), the average dose jumps up to 600 millirem per year.  This is what we all get every year and bears no known, measured relationship to developing cancer.

  • Note: For the international units, divide all “millirem” numbers by 100, (i.e. 3.6 millisieverts.)  Or, an online converter can be found here.

However, what does that mean?  I’m completely aware that unless you’re a professional in the field of health physics, (as I am,) this number has no context.  So, allow me to explain just what this really means using things we can all identify with.

Hold on to your hats.

So, What’s My Dose?

For context, below is a list of the amount of radioactivity you receive in a year from very familiar items/sources:

  • Cosmic radiation  = 26-96 millirem (higher with altitude)
  • From standing on the Earth itself (geology) = 20-90 millirem (higher nearer igneous mountains)
  • From your own brick/stone/concrete building = 7 millirem
  • From your own body (food/water!) = 40 millirem
  • From breathing (naturally-produced radon) = 200+ millirem
  • For flying 1,000 miles in an airplane = 1 millirem
  • From having a dental/chest/normal x-ray = 50 millirem each
  • From having an annual mammogram = 75 millirem
  • From having a single CT scan = 150 millirem
  • From smoking a pack of cigarettes a week (polonium) = 200 millirem
  • From consumer goods = 10 millirem

Just add these up to produce your own, custom average annual radiation dose.

Wait.  My house/food/body/atmosphere is radioactive?

Yes.  Not to fear.  Just like the small amounts of chemicals that we can reliably tolerate, (e.g., trace arsenic, lead, etc.,) so too are trace amounts of radioactivity completely tolerable.

Fukushima in Context

Now, as you can see in the above plot of the radioactivity measured at the entrance of Fukushima nuclear powerplant as the disaster happened, it looks pretty dramatic.

  • (Note: The numbers are reported in “micro”sieverts per hour, which are admittedly reading a much smaller span of time, (hours versus years,) but are in units 1,000 times smaller than the “milli”sievert international units described above.  This is important.)

However, instead of running for the hills just yet, let’s take a look at what the numbers actually say.

The March 15th hydrogen explosion at the plant, which occured roughly 84 hours after the earthquake, shows the largest spike of activity: for a brief period upwards of nearly 12,000 microsieverts per hour.

But let’s take this apart.  What does that mean?  12,000 microsieverts is the same as 12 millisieverts.  12 millisieverts is the same as 1,200 millirem.

Now, compare this to the above list of natural radiation values, with an eye toward the annual average does of 360 millirem.

Yes, if reading correctly, this implies that simply standing on planet Earth every year nets everyone the same external radiation dose that would have been received if standing at the gates of the Fukushima Daichi powerplant during the worst part of the disaster for a full 15 minutes.

With these, even worst-case numbers, it becomes obvious that one could stand at the entrance to Fukushima during the worst period of the disaster for a full three minutes and have earned only the equivalent radiation dose of… an average chest x-ray.

Granted, this isn’t something one would necessarily want.  This is upwards of 15% of your natural average dose.  -But your biology wouldn’t ever notice the difference.  And one could go many orders of magnitude more than that before there would be any reasonable expectation of an acute health effect.

More realistically, even standing at the Fukushima gates during the unprecedented event of external venting from the internal containment of reactor number 2, (with an exposure rate of 0.5 millisievert per hour), it’s a full hour of loitering there before one would rack up the external exposure of simple set of dental x-rays.

Funny how the perception and the reality differ, eh?

Unwanted radioactive material is serious, just as a leak from underground gasoline storage tanks that could contaminate drinking water is serious.  But that seriousness must be given honest context.

Take-home

Hopefully this has provided a window into the reality of radiation protection, and it is my sincere wish that this was and will continue to be a useful go-to when radiation numbers come up in the media.

Feedback is welcome, and if desired, I would be happy to put other radiation values in context… (Chernobyl, Three Mile Island, going to the Moon, etc.)

Go forth and combat radiation misinformation!

[Sources for the above information: American Nuclear Society, the National Council on Radiation Protection and Measurement, the U.S. Department of Energy.]





Radiation, Japan, and Irresponsible Reporting: Part IV

29 05 2012

(Credit: Jeremy Gwin)

This post has been lying in wait for quite some time.  I thought it best that I let it simmer and distill for a while… The truth is that I was simply getting too frustrated with the Fukushima coverage to compose a sensible post.  Now, with a little extra time and perspective, please allow me to present Part IV (relative to previous Parts I, II, and III) of my attempt to throw a cup of knowledge onto the raging inferno of misinformation out there relating to “radiation” and the media/cultural fallout (ahem) from the reactor failures in Japan. 

Just how bad is it?  Read on.

Media Blunders

A year ago, just when I thought the tide was turning on the sensationalistic coverage of nuclear reactor incidents in Japan and elsewhere, the media pulled another wave of cheap stunts.  -I had been just about ready to bury the hatchet, and I suddenly realized that it needed sharpening.  Much sharpening.

With (it seems) an ebb-and-flow that correlates to how sensational (or boring) other news is at the time, adding to my deep-seated suspicion that “radiation”-stories are linked to low ratings, the Fukushima coverage swung ’round from simple paranoia and approached raving madness.

Let’s start with this article:  http://www.reuters.com/article/2011/06/28/us-japan-nuclear-idUSTRE75Q1EV20110628

(Credit: The Coleman Company)

When we get into the guts of the piece, the info finally comes out that the amount of radiologically-impacted water in question included only 15 tons and that it was low level radioactivity that was discovered.  That’s important info!  Nay, the most important info.    “Low level” radioactivity includes Coleman lantern mantles, tritium watch luminescence, and americium in smoke detectors – things you already own, wear, or have in your house. 

(Indeed, as I have mentioned in the past, you yourself emit low levels of gamma radiation – see: Potassium-40).

Then, let’s move on to this Fox News article about radioactive isotopes found in breast milk in Japan:  http://www.foxnews.com/health/2011/05/19/radioactive-substances-breast-milk-5-japanese-women/

First, the good.  The title of the report states that “radioactive substances” have been found in the breast milk of several Japanese women.  That’s good.  At least we’re moving beyond misnomers like, “Radiation found in breast milk.”

However, then there’s the bad.  And it’s really bad.  The amount of radiation discovered is given no real context.  (The author perhaps didn’t understand it in the first case.)  In fact, while the activity of radioactive material discovered is explained to be nearly a hundred times beneath any safety limit, the critical information is that these limits themselves are far below the range where any negative health effects are to be expected.  Further, if a similar survey were performed in the United States, (with no relation to Fukushima,) radioactive substances would be identified in a proportion of the population.  Seriously.  -And contrary to what stark opponents would have you believe, there are such things as incidental doses of radioactive material.  Our bodies are built to withstand it.  (Radioactive material is naturally-occuring, after all.)

Down the Misinformation Rabbit Hole

Then, we go from bad to worse.  Surprisingly, the top recent offender here was on CNN.  In what I can describe as nothing more than a blatant scare segment, I found myself completely floored when Dr. Michau Kaku, a theoretical physicist whose popular books I greatly admire, was guilty of not only fanning the irrational fear of “radiation,” but he himself uttered the greatest fear-mongering statement I have ever heard.

‘We “came close” to losing northern Japan!’

…What?!  Lost it?  You mean, Dr. Kaku, that the county turned left instead of right, and a clerk at the front of the store had to call on the intercom to get Northern Japan to reunite with the rest of the country?

Liquid Disposal Inc. chemical superfund site. (Credit: EPA)

C’mon!  Unbelievable, and patently untrue.  The Fukushima cleanup will be a difficult but not insurmountable decontamination and decomissioning project.  -This is no different than a cleanup of a historically-toxic steel mill or other major industrial installation that has the potential to release contaminants into the environment.  (See: Superfund Projects.)

Scary Because it Sounds Hip

Then, there’s reporting from the likes of the following articles, (and I otherwise completely love Gizmodo,) spewing misused terminology and editorials-as-fact like Linda Blair does green soup in the Exorcist.

http://gizmodo.com/5824536/japanese-nuclear-emergency-director-you-have-no-right-to-a-radiation+free-life

http://gizmodo.com/5834721/fukushimas-leaked-168-hiroshima-blasts-of-radiation

No one has the right to a radiation-free existence, a statement that is assailed in the first story.  A giant gravity-driven nuclear fusion reactor lights our sky every day.  Hundreds of thousands of similar fusion reactors bombard our planet with cumulative radiation at all times from space.  Radioactive material resides in a great proportion of the rocks around us and bombards us from all sides.  And even plantlife, rich in potassium, hits us with radiation whenever we near it.  Our DNA repair mechanisms arose in such an environment, and it typically causes us no concern at all.

Godzilla, a surviving prehistoric oceanic dinosaur mutated and angered by atomic blasts. (Credit: Ishirô Honda)

And regarding the second story, relating a fission reactor to an atomic bomb borders on criminally sensational.  Terms like “terriby dangerous” and “particularly lethal” are tossed about to great effect with no apparent understanding of their context.  And while relating Fukushima to Hiroshima in “bequerels” – a unit of radioactivity – they speak about the release of cesium as though it is in terms of mass.  It is not!  The activity of the Cs-137 released to the environment in bequerels is very different than the amount of Cs-137 released to the environment in grams – and activity decays with time.  So to say Fukushima is the equivalent of 168 “nukes,” (another misnomer,) mixing up descriptions with unit types, and tossing around editorial qualifiers, it is completely clear that the author has no idea what he is really talking about.  -Only that he fears it and apparently wants a catchy lead line.

  • To the point: The human body possess ~4.4 MegaBequerels of activity from Potassium-40.  The radiation released from the population of the United States just standing there already amounts to more than a TeraBequerel.  The rocky mountains contains millions of TeraBequerels of radioactive material, if you want to quantify it that way, (which is odd.) 

Literally, though while not encouraged, the Fukushima release is a drop in the bucket.  A statistical bump.  It’ll be scientifically traceable for years to come, but it won’t cause Godzilla to emerge from the seas to destroy Tokyo.  And it certainly isn’t the equivalent of “168 Nukes.”  Or at least, not in the way the author seems to be intending it.

Piracy-induced Global Cooling, and Other Correlation Fallacies

I’d be remiss if I didn’t mention this completely insane and somewhat retracted story claiming that a bump in infant mortality had been attributed to the slight rise in detectable radioactive material breezing over the United States after the Fukushima incident:  http://www.prisonplanet.com/physician-and-epidemiologist-say-35-spike-in-infant-mortality-in-northwest-cities-since-meltdown-might-be-the-result-of-fallout-from-fukushima.html

Modern radiation detection instrumentation is extraordinarily sensitive.  We regularly detect single photons interacting with a detector crystal, log it, and perform statistics conducted over several hours or days.  This allows scientists to make statements like, “A 30% increase over background,” which is essentially measuring 30 times zero. 

So, the levels of radiation detected over the U.S. in this case were far, far beneath what a human body would even notice on planet Earth.  (Let me put it this way – the radiation intensity of a granite countertop would wash out the signal.)  The idea that this “gee-whiz”-grade radiation could have caused anything to infants – in such a short span of time (!) – was patently ridiculous, and physically impossible.  (There is no mechanism for such a miniscule amount of radiation to have casued any damage that led to infant death in such a short amount of time.)

(Credit: Church of the Flying Spaghetti Monster)

I am reminded of the now-classic Flying Spaghetti Monster example of a correlation fallacy which states:

  • Since global temperatures have gone up as seaborne piracy has been eliminated and the world’s oceans made more secure, a lack of pirates in the ocean demonstrably causes global warming!  Therefore, to combat global warming, we must put more pirates out on the seas!

This is an over-the-top example of how correlation does not indicate cause-and-effect.  Just so, the authors of the aforementioed study sought to politically paint radiation as a “bad guy” and simply found a correlation, making no effort to tease out cause-and-effect.  As was later made clear, there isn’t any in this case. 

Yet another example of rampant cultural anti-radiation/radiation science bias.

Wading through the Spin

Honestly, the situation at the Fukushima reactors is no picnic, without a doubt.  However, needless sensationalism in the media continued, especially when the category of the accident was upgraded to level 7, “the same as the Chernobyl disaster!”    

… *sigh* … Let me try to untangle this one. 

The important thing here is that a “level 7” event has no ceiling.  That’s it.  Once something crosses the threshold, whether just met or far exceeded, the event would be classified the same.  The Fukushima event is much closer to the former, whereras Chernobyl is more the latter.

http://www.world-nuclear-news.org/RS_Fukushima_moved_to_Level_7_1204111.html

In reality, despite the classification, the Fukushima incident is still more like Three Mile Island than Chernobyl for very specific reasons.  (The Three Mile Island nuclear accident is still synonymous with nuclear terror, yet how many people were killed?  Zero.  In the end, radioactive iodine was detected in local milk at a dose much less than one would receive from ingesting a single banana.  This is how badly the scenario has been spun.) 

Risk.  It’s all about risk.  Three Mile Island arguably did not perceptibly increase the risk of negative health effects to people in the region at all.  Now, look at the risk involved with cars.  The automobile involves combustion explosions, toxic chemicals, sparking fires, asphyxiating fumes, deaths from vehicle malfunctions or accidents, etc.  By simple math (number of injuries, illnesses or deaths per year,) cars are extremely dangerous – far, far more dangerous than nuclear reactors – and if you subscribe to anthropogenic (man-caused) climate change, running these CO2-spewing devices all over the world has a much greater potential for ecological impact than do nuclear reactors, ignoring the fact that most underground fuel storage tanks at gas stations regularly leak into the environment(!).

If the media waved the risk of driving cars in everyone’s faces the way nuclear power gets hammered, everyone would immediately call for banning cars… and this is especially pointed considering that tens of thousands of people actually die annually on the roads, as opposed to the zero annual deaths due to nuclear powerplants.

Let’s look at the risks of death in context:

  • Annual traffic fatalities in 2010:  ~33,000
  • Annual deaths in 2009 due to common chemicals:  ~1,500
  • Annual deaths due to nuclear powerplants and/or radioactive waste:  0

(The irony here is that the ionizing radiation exposure that is actually likely to cause an increase in cancer is the one no one really fears:  Medical x-rays and MRIs.  We’re getting more of them these days, and because this is ionizing radiation just like that being emitted by Fukushima, cancer statistics will likely see a bump as a result.)

Airline flight attendants receive a much higher radiation dose than any nuclear powerplant worker due to their proximity to cosmic rays (radiation) from space.  No one worries about flying, and everyone worries about the nuclear powerplant next door.

(For a concise versionof the nuclear safety argument, see my comment string here: http://wensdaymedia.wordpress.com/2011/06/27/fort-calhoun-nuclear-plant-update/#comment-8 )

A Final Thought

In terms of environmental impact, the Fukushima incident is arguably less significant than the Exxon Valdez or the BP oil spills, and it is on-par with the superfund sites I mentioned earlier.  Not rosy, but not the end of the world. 

So, how is it that so much fear and panic has been generated, trumping so many other more prevalent risks, when it is based literally on hot air?  It is a mystery to me. 

Perhaps it can be attributed ultimately to a habit of fear regarding radiation.

If we imagine the alternative – a culture providing socially unimpeded support for atomic and nuclear energy, power, and technology, (since our culture already awards this to toxic chemical technology,) we may well have already solved many of the energy problems of today.  Ancient stars worked tirelessly to produce the radioactive elements common in the deep Earth and sprinkled throughout the planet’s crust.  Misused, they are harmful.  Wisely used, they present energy sources with the ability to outlive our planet and our star.  (Talk about efficiency!)

In any event, my final point is to simply keep a critical eye open when it comes to media coverage of radiological events.  Watch for how infrequently health physicists or radiological engineers who are speacialists in nuclear technology are interviewed.  -And hopefully, if you’ve arrived at the end of this long-winded tirade, this has given some food for thought. 

Until next time!





Proposing an Antimatter Hazard Symbol

6 05 2010

Proposed Antimatter Hazard Symbol. Credit: Me

As the most potent potential fuel we are familiar with at this stage in our development as a civilization, I think it’s time we talk about getting serious about Antimatter.

For those unfamiliar, Antimatter is atomically identical to normal matter, but electrically (and subatomically) backward.  Electrons become positrons, and protons become anti-protons, particles with opposite electrical charges.  (Think of flipping over the batteries in your remote control, so the “plus” side is now the “minus.”)  Anyway, when matter and antimatter interact, they are both completely anihillated and converted to pure energy in a release that makes nuclear warheads quake in their boots.  (Gene Roddenberry had it right 40 years ago when he powered his fictional interstellar craft with it.)

To this day, Antimatter is the only thing we know of that could power inter-star-system or galactic space transportation technology, real or imagined, and get the job done in a practical amount of time, (read: a single human lifetime).

This brings us to the present, where I currently find myself buried in 10 CFR 835 federal regulations for work.  They’re the regulations our government has put into place to protect workers and the public from sources of radiation and properly warn them of areas of radiation and radioactive contamination.  These rules relate heavily to symbology and the implementation of the familiar yellow-and-black radiation symbol.

You can see where this is going.  Should we decide to seriously consider Antimatter as the fuel (read: energy storage) source that it has the potential to be, we are going to need to seriously consider warning people about it.  The first step is creating a hazard identity.

There have been a couple of attempts at an Antimatter Hazard Symbol floating around the web, but I haven’t found that they adequately address the risks nor do they necessarily coincide with accepted symbology.  Why not start with something familiar?  I think the radiation tre-foil is panic-inducing enough to serve as an acceptable starting point…

So, the thought evolution of my proposed antimatter symbol is simple:

  • The trefoil already represents radiative energy from a point, so why not start there?  It’s already internationally recognizable.
  • Instead of one point in the symbol center, use two overlapping inverted-color circles, representing the interaction of matter and antimatter.
  • Instead of solid trefoil blades, bisect them to provide the visual appearance of even more energy released than radioactive matter.
  • Instead of yellow, a warning color, use red, a color associated with grave danger or death.  The background color doesn’t matter so much, as long as it provides a high contrast with the red.  I like navy, violet, or black.

And there you go.  People will get it, even if they aren’t specifically familiar.  It immediately looks like a radiation symbol, only worse.  Stay away.  Find someone who has proper instrumentation and knowhow before you start messing with whatever you’ve got in your hands with this symbol on it.

UPDATE 04/2012: For more info and subsequent uses of the symbol, click here!

Thoughts, anyone?

Better in black? (reader-suggested)

Second, modified example: (feel free to use any of these in your own projects/work!)

Credit: Ben McGee








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