System of Fear: A Dose of Radiation Reality

14 10 2013

In line with last week’s post, please see the below infographic, which paints radiation doses in the visual context of a sort of system of planets according to size (click to enlarge):

SystemofFearI

As is plainly evident, it’s shocking how much the public perception of radiation doses and negative health effects differs from reality.

(For example, in today’s perceptual climate, who would believe that a person could live within a mile of a nuclear powerplant for a thousand years before receiving the radiation dose from a single medical CT scan?)

If feedback to this is positive, I think I’ll make this the first in a series of similar infographics.  (Perhaps people would find it interesting/useful to next have illustrated the relative magnitudes of nuclear disasters?)

_______________________________________________

If anyone doubts the numbers in the above diagram, please feel free to investigate the references for yourselves!

International Atomic Energy Agency:
http://www.iaea.org/Publications/Factsheets/English/radlife.html

U.S. Environmental Protection Agency:
http://www.epa.gov/radiation/understand/perspective.html

U.S. Nuclear Regulatory Commission:
http://www.nrc.gov/about-nrc/radiation/around-us/doses-daily-lives.html

U.S. National Council on Radiological Protection (via the Health Physics Society):
http://hps.org/documents/environmental_radiation_fact_sheet.pdf

U.S. Department of Energy:
http://lowdose.energy.gov/faqs.aspx#05

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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.]





Forward Backward Thinking: Pipelines and Deep Time

22 11 2011

A bit of a long-winded digression today, but as a physical scientist at heart I can’t help myself.  I’m riled.  (Riled to the point of considering expanding the rant to follow into an article submission to the journal Ground Water or perhaps Arid Environments…)

Allow me to explain.

Industry vs. Academia

Me - seeking an elusive industry+academic science subculture balance.

First, for those who haven’t been long-time readers, I should mention that I’m something of an enigma as a scientist: I’m an academia-industry hybrid.  In my experience, this isn’t normal; We tend to be either-or.

Often, in one corner, there are career field scientists (with often nothing more than a bachelor’s degree) who have spent their professional lives out “in the field,” dealing with practical problems, earning the kind of experience and “sixth-sense” about their specialty that can only be earned with the expenditure of time, blood, sweat, and tears.  They tend to hold in disdain the highly-credentialed-and-published academic scientist, with little comparable field experience and much effort spent on apparently esoteric pursuits, who swoops down from a perch in the ivory tower to tell the field scientists “how it really works” because of research they’ve performed, etc., etc.  (They’re un-apologetically incorrect often enough, due to a real-world complexity or oversight, to really turn off the field guys.)

In the other corner is the committed academic, (often sporting graduate or doctoral degree[s],) having spent a career researching to understand the subtleties of process in natural systems and who has worked long years to improve scientific understanding or the powers of prediction.  They tend to hold in disdain the provincial field scientist, who sports a requisite chip on his shoulder (a growth resulting from years spent in the field,) who believes he already knows everything without having even attempted the more sophisticated understanding of process that comes with years of academic work.  (They often resist changes in instrumentation or methodology that might yield better data due to a “how we’ve always done it” mentality.)

In my view, both are right, and both are wrong.  Each has something supremely valuable to offer the other, but neither side wants to hear about it.  Usually when the two collide out in the field, head-butting ensues.  Sometimes spectacularly so.

The Long Now and the Long Then

In any case, this brings me to the subject at hand: a current clash between academic and practical views of the natural world, science’s role in it, and how few seem to be able or willing to see reality through the garble.

Northern Spring Valley, NV. (Credit: Ben McGee)

Specifically, the Las Vegas Review Journal recently reported that the Long Now Foundation, an organization aimed at promoting deep-time-style thinking to current and future human planning, has come out in opposition to the Southern Nevada Water Authority’s East-Central Groundwater Development Project, a freshwater pipeline venture intended to relieve for southern Nevada communities the effects of prolonged drought on the Colorado River system.

I’m torn because I’m a long-time supporter of both endeavors.

The Long Now Foundation, among other pursuits, has designed and is planning to build a 10,000 year clock.  Why?  Designer and inventor Danny Hills puts it directly:

I cannot imagine the future, but I care about it. I know I am a part of a story that starts long before I can remember and continues long beyond when anyone will remember me. I sense that I am alive at a time of important change, and I feel a responsibility to make sure that the change comes out well. I plant my acorns knowing that I will never live to harvest the oaks.

As a geologist and planetary scientist, an awareness of the depth of time that precedes us colors my view of the future.  I’m concerned about humankind’s ultimate fate on a geologic timescale, what with broader and potentially civilization-ending threats, such as impacts from space, supervolcanoes, and proximal supernovas.  I have an affinity for, well, us, and I want to make sure we make it in the long run.  That’s one of the reasons I’m such an advocate for human space exploration.

I wholeheartedly agree that we need to plan much, much farther out, and I believe projects like the 10,000-year clock will really help people start thinking about it.  However, that doesn’t mean that human lifespan-range planning should stop – Indeed, there is some reason to believe that long-range plans are rarely feasible because they are inevitably created “by committee,” and anyone who’s worked in a highly bureaucratic environment knows how that turns out…

Precautionary Principle vs. Real-World Problems

So, why do the Long Now folks oppose the pipeline?  Well, here is where I believe the classic “industry-versus-academia” problem begins to rear its head.  You see, I spent more than two years as a front-line hydrogeologist on the pipeline project.  I helped design and implement a sprawling, 1,400-square-mile precipitation monitoring network for the project in addition to installing gaging stations, flumes, and repeatedly measuring every stream, creek, spring, and groundwater well for nearly a 300-mile stretch along the proposed pipeline’s reach.  I performed data quality assurance checking and verification for the project’s central database, analyzed precipitation/surface-water/groundwater response mechanisms, and used satellite imagery to reconstruct the historical extents of ephemeral lakes in the region to calculate their water storage.

Spring Valley, NV, near the proposed pipeline reach. (Credit: Ben McGee)

In short, I was in this data, cradle to grave.  According to everything we collected, the groundwater system and water budget for each of the pipeline’s basin and range valleys could definitely handle the proposed pumping scheme.  Further, proposed pumping rates were highly conservative, and there were an array of biological vectors that required constant monitoring so that we’d detect an unlikely change in the ecosystem as soon as it happened and shut the pipeline down for evaluation.  (And then there’s something else**, which I’ll return to at the end of this post.)

Now, while I appreciate the severity of the drought affecting the region and the need to proactively prepare to secure a backup water supply for Southern Nevada, the academic perspective on engineering projects of this scale tends to be more aloof.  In stereotypical academia, the precautionary principle, (which I support in large part,) is always given top priority (apparently irrespective of what the field data supports,) which means that any major project should essentially never be attempted without many decades of preliminary research.  I’ve worked long enough off-campus to realize that idealized scenarios like this aren’t tenable in the real world, (primarily due to cost,) and we need to do something about the drought more decisively.  Hence the root of academia-industry tug-of-war at the onset of this particular issue.

The more “traditional” opposition to the water authority’s pipeline project takes the form of emotionally-charged but completely illogical concerns about  creating “the next Owens Valley,” despite the fact that there is no body of surface water to deplete a’ la Owens Valley, or about  “destroying the ecosystem,” despite the fact that groundwater tables are far beneath the depth of even the most invasive phreatophyte, several hundred to more than a thousand feet.  (This means should the groundwater table be lowered as a result of pumping, neither surface streams nor the ecosystem would have any way of knowing about it.  It’s akin to alleging that excavating beneath a waterfall will speed up the falling water = defies laws of physics = nonsense.

By contrast, I suspect that the Long Now Foundation opposition to be different and somewhat more sophisticated in that it they will likely oppose the project by alleging that it does not represent suitably “long term” planning.  Certainly, the pipeline is subject to multi-century-scale changes in regional climate should such changes occur.  However, this caution does not award the field data or the administrative controls their due credit, and it fails to take into account the human factor – that there are communities that will rely on this project’s timely execution.

**And Another Thing

Here’s the kicker.  For reasons that mystefyingly are never considered, the water authority’s precipitation estimates, (particularly concerning snow, the source of the water for any water budget in an arid mountainous environment,) are already conservative, even without working on limiting pumping impacts.  Why?  Because the precipitation gauges maintained by them, the National Weather Service, and the United States Geological Survey  fail to catch nearly 50-80% of the falling snow!

Unlike the rest of the developed world, for some reason, the United States fails to consistently include wind shields on their rain and snow gauges, resulting in an under-reporting condition of up to 80%.

This means that all national precipitation data is being under-reported to at best an unknown extent, and (ignoring the implications for apparent measurements of climate change) the data being used to determine watershed baselines for the pipeline project is automatically conservative, for there is more water in the system than is being accounted for.

Check it out for yourself.  Visit a weather station if you can find one nearby.

This is something I have yet to see considered in print, and it is high time, in my opinion.  (Stacking that on the “to-do” manuscript pile.)  Why is it that during the course of the conversation between opposing scientific factions doesn’t anyone either independently or together appear to recognize this as a problem?!

Last Words

We simply need more thoughtful scientific engagement by academic groups when it comes to automatically opposing human engineering where natural systems are concerned.  Forward thinkers shouldn’t automatically oppose human activity or progress, while industry scientists shouldn’t be so opposed to taking a step back and considering the Long Now.

It seems as though in most cases the data obtained and presented by the “industry” side of the fence isn’t even explored by those who oppose it on ideological grounds.  In far too many cases baseless accusations of data bias, manipulation or forgery are automatically assumed, which is a gross disservice to the scientists hard at work in industry – many of whom consider themselves shielded by the data against retribution.  (One can’t get fired for obtaining unfavorable data, and I dare a project manager to try and see how loudly an irked and disenfranchised scientist can blow a whistle.)

In any case, I suppose all I’m trying to say is this:

Can’t we all come to agree that we need both the higher-level, academic understanding of natural processes in addition to the wisdom of boots-on-the-ground experience in data collection and exposure to natural systems in order to make a smart, humane, conscientious, and successful civilization possible?

Can’t the Long Now Foundation recognize the practical (and urgent) utility of the pipeline and engage the Southern Nevada Water Authority to help them to improve their modeling efforts? Can’t the Water Authority recognize the wisdom in the Long Now Foundations considerations of long-term sustainability and invite them to take part?  Can’t both sides work together to help the collective improve the understanding of the field at large(unshielded rain gauges) while simultaneously working to benefit society?

Wishful thinking, I know…  But perhaps, someday, we’ll cross the divide in scientific culture and all be better for it.








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