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Question on Background Radiation

by Crazy Horse Wed Mar 30th, 2011 at 05:29:11 PM EST

This is worse than an LQD. This diary is simply a question.
What is the influence of atmospheric nuclear detonations, greater than 2,000, AND the sum total of accidents (accidents?), on measurement of background radiation?


We know about radon (at least somewhat), and we know about bananas, and current knowledge of potassium isotopes in the body. We know that flying gives us x, and dental or chest x-rays give us y or z.

But do we know what normal background radiation is? Is there any data which shows change in background radiation from civilization?

I won't list all the places that are leaking since the late 40's. I'm only wondering.

I'm not inclined to disparage arguments of normal background radiation, like everytime you fly x km. I'm even willing to entertain the notion that living on a planet which exists in deep space has some attendant risks.

I'm just wondering how we know what background radiation is, and how we came to that knowledge. Can i get some help?

[editor's note, by Migeru] Japan threads:

Display:
I guess i mean, is background radiation some form of constant? Is it location dependent? (Duh.) Does it change over time, with the addition of our stuff? And since when did we know what backgound radiation was?

One example of why i want to know: When building codes for passive solar were considered, radon gas was one driver.

Is this discussion even an issue?

"Life shrinks or expands in proportion to one's courage." - Ana´s Nin

by Crazy Horse on Wed Mar 30th, 2011 at 06:08:25 PM EST
is background radiation some form of constant?

Hell no.

Is it location dependent? (Duh.)

As you say. There are rocks with lots of radioactive isotopes and ones with few. In connection with that, radon (a radioactive inert gas escaping from bedrock) is produced differently in different locations, and collects up in cloed rooms if you don't ventilate. Cosmic radiation reaching you depends on altitude (hence the airplane thingy, but it also makes a difference on high mountains).

Does it change over time

Yes. Part of background radiation is cosmic rays, that changes thanks to the Sun kicking the Earth's magnetic field and such. Volcanoes spew material with relatively high radioactive content. So do coal-fired power plants. And nuclear dumps and mines.

On global average, human addition is dwarfed by the natural and its variation. It gets troublesome if it gets concentrated at some places.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Wed Mar 30th, 2011 at 07:13:49 PM EST
[ Parent ]
Here is a diagram prepared by Japanese authorities. It clearly tries to suggest that nuclear is not dangerous and has stupid cartoons and even more stupid comparisons of daily and annual radiation exposures, but it can still give you an idea of the scale for various other sources.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Wed Mar 30th, 2011 at 07:20:55 PM EST
[ Parent ]
Danke DoDo, at least one of my questions is answered. The presentation shows anthropogenic fallout worldwide at 3.8%, based upon stats from 1992, (Adapted from UNSCEAR Report 1992,and Life environmental
radiation」Former Science and Technology Agency ( Japan), but of course who knows the accuracy of the stats.)

Strange that the per person levels for Japan are much lower, with medical radiation so much higher (that i understand, as compared with say Cote d'Ivoire.) In fact, what factors were used upon what data foundation to get a worldwide per person dose?

"Life shrinks or expands in proportion to one's courage." - Ana´s Nin

by Crazy Horse on Fri Apr 1st, 2011 at 05:27:39 AM EST
[ Parent ]
That 0.11 mSv/year figure was the peak value in 1963. Says so the 2008 UNSCEAR report (page 4), which puts the global average residual contribution of atmospheric testing at 0.005 mSv/year, and that of dispersed Chernobyl fallout at 0.002 mSv/year (reduced from 0.04 mSv/year in 1986).

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Fri Apr 1st, 2011 at 05:53:27 AM EST
[ Parent ]
which puts the global average residual contribution of atmospheric testing

The then current level, I mean.

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Fri Apr 1st, 2011 at 05:55:06 AM EST
[ Parent ]
※Fallout : the residual radiation hazard from a nuclear experiment

rather than dropping bombs on peoples countries? one would thought that it would be one thing that people in Japan might remember

Any idiot can face a crisis - it's day to day living that wears you out.

by ceebs (ceebs (at) eurotrib (dot) com) on Fri Apr 1st, 2011 at 11:34:24 AM EST
[ Parent ]
A case can be made that the only recorded dropping of nuclear bombs on other people's countries were, in fact, live-fire experiments more than they were acts of war.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Fri Apr 1st, 2011 at 09:21:01 PM EST
[ Parent ]
And here's a different version, compiled by the World Nuclear Association:

Whoops, were did it go?

"Life shrinks or expands in proportion to one's courage." - Ana´s Nin

by Crazy Horse on Fri Apr 1st, 2011 at 11:08:16 AM EST
[ Parent ]
In the accompanying text, they have this:

Radiation | Nuclear Radiation | Ionizing Radiation | Health Effects

Less than 1% of exposure is due to the fallout from past testing of nuclear weapons or the generation of electricity in nuclear, as well as coal and geothermal, power plants.


*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Fri Apr 1st, 2011 at 11:30:12 AM EST
[ Parent ]
There you go again, expecting me to be able to read all this stuff. '-)

"Life shrinks or expands in proportion to one's courage." - Ana´s Nin
by Crazy Horse on Fri Apr 1st, 2011 at 12:54:50 PM EST
[ Parent ]
The nuclear fuel cycle does not give rise to significant radiation exposure for members of the public.

Tell that to the Navaho children who died from cancers caused by uranium mining.

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre

by ATinNM on Fri Apr 1st, 2011 at 01:14:32 PM EST
[ Parent ]
That's from heavy metal poisoning, not radiation. But yeah, to say that the fuel cycle is safe after the fuckup in Fukishima is asinine.

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Fri Apr 1st, 2011 at 01:18:18 PM EST
[ Parent ]
Ack the correction.

I was so angry my fingers got the better of my (non-working) brain.


She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre

by ATinNM on Fri Apr 1st, 2011 at 01:27:57 PM EST
[ Parent ]
For location dependence, check this map of Germany. The association with certain mountains is obvious.

*Lunatic*, n.
One whose delusions are out of fashion.
by DoDo on Wed Mar 30th, 2011 at 07:28:02 PM EST
[ Parent ]
The Japanese chart assumes you are getting several times this from various--friendly! ;)--sources, but still it is the same order of magnitude.  

The German map is pretty well centered on one mS/yr.  

Since there is no safe level of radiation exposure (well, the universe just isn't a safe place, you know?--or rather, literally, radiation damage has no threshold.)  this is one end of your risk yardstick.  At the other end lies short exposures (within a few days) of 1000 mS (likely radiation sickness) or 6000 mS (LD50, even with medical treatment).  

In the middle:  At radiation levels below 10 mS/yr cancer rates tend to drop into the noise of cancers due to earth background, above that level they become statistically measurable.  

The Fates are kind.

by Gaianne on Wed Mar 30th, 2011 at 08:58:49 PM EST
[ Parent ]
For radon, check out this:

WHO | Radon and cancer

  • Radon is the second most important cause of lung cancer in many countries.
  • Radon is estimated to cause between 3% and 14% of all lung cancers, depending on the average radon level in a country.
  • Radon is much more likely to cause lung cancer in people who smoke, and is the primary cause of lung cancer among non-smokers.

...Significant health effects have been seen in uranium miners who are exposed to high levels of radon. However, studies in Europe, North America and China have confirmed that lower concentrations of radon - such as those found in homes - also confer health risks and contribute substantially to the occurrence of lung cancers worldwide [1, 2, 3].

The risk of lung cancer increases by 16% per 100 Bq/m3 increase in radon concentration. The dose-response relation is linear - i.e. the risk of lung cancer increases proportionally with increasing radon exposure. Radon is much more likely to cause lung cancer in people who smoke.

I was made aware of the radon danger as a freshman physics student. Our professor told about an especially bad cluster west of Budapest: a coal mining town, where (1) natural radon emissions from the ground are high due to minerals with high radionuclide concentration, (2) homes were built in the sixties without proper ventilation, (3) buring locally mined (high radionuclide concentration) coal produces slag with even higher radioactivity (the fire leaves behind and thus concentrates heavy metals) which legally up to 1960 and illegally until much later was used as building material, (4) the building material produces more radon gas as breakdown product (radon-222 is the alpha decay product of radium-226).

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Thu Mar 31st, 2011 at 04:46:28 AM EST
[ Parent ]
Where does the radon go?  It's a dense gas, and it leaks out whether there is a house there or not, so how does ventilating help?
by njh on Thu Mar 31st, 2011 at 05:59:31 AM EST
[ Parent ]
I'm not sure I understand the question. By dense, do you mean high atomic mass or high concentration in da house? By leaking out, do you mean from the ground or from the closed room?

On the longer run, BTW, the problem is not radon itself with its short half-life but its (not inert gas) breakdown products, which stick to dust particles (and cigarette smoke, hence the enhanced cancer rate in combination IIRC).

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Thu Mar 31st, 2011 at 06:16:06 AM EST
[ Parent ]
by dense I mean it weighs a lot per unit volume, and hence tends to sink.

by leaking out, I mean from the ground.

my point is really that the concentration of radon should be roughly uniform inside and outside, because it is being provided and decayed at the same rate.

I didn't realise the connection to cigarettes.

by njh on Thu Mar 31st, 2011 at 06:41:45 AM EST
[ Parent ]
The volume of air per square meter of ground depends on how high your ceiling is. As ceilings go, the troposphere/stratosphere boundary is pretty high.

And as far as the higher density goes, it does increase the ground-level partial pressure (and thus the concentration per cubic meter) in equilibrium. But the troposphere is not in equilibrium - there is rather significant convection.

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Thu Mar 31st, 2011 at 06:57:06 AM EST
[ Parent ]
by dense I mean it weighs a lot per unit volume, and hence tends to sink.

Ading to JakeS: you do mean atomic weight in the end (radon mass per unit volume at a given air pressure depends on concentration). But it is actually true that radon can concentrate in 'poodles' due to stratification of still air (in a basement or mine).

*Lunatic*, n.
One whose delusions are out of fashion.

by DoDo on Thu Mar 31st, 2011 at 07:46:25 AM EST
[ Parent ]
"radon can concentrate in 'poodles'"


A victim, yesterday.

by LondonAnalytics (Andrew Smith) on Thu Mar 31st, 2011 at 09:40:05 AM EST
[ Parent ]
I don't know what other definition of density there is apart from molecular weight, for gases.  I think you are confusing with concentration.

I'll leave the poodles for LondonAnalytics.

by njh on Fri Apr 1st, 2011 at 06:30:56 PM EST
[ Parent ]
Radon - Wikipedia, the free encyclopedia
Its most stable isotope, 222Rn, has a half-life of 3.8 days.
Which means that ventilation mixes it with the broader atmosphere and reduces the exposure from being near granite.

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Fri Apr 1st, 2011 at 05:53:55 AM EST
[ Parent ]
On global average, human addition is dwarfed by the natural and its variation.

With the caveat that open-air nuke tests are dirty. Back in the bad old days before the 1963 test ban treaty, background from nuke tests hit 7 % of natural background (and climbing - meaning that if we'd kept up atmospheric nuke tests at the same rate it would have stabilised considerably above 7 % of natural background).

- Jake

Friends come and go. Enemies accumulate.

by JakeS (JangoSierra 'at' gmail 'dot' com) on Thu Mar 31st, 2011 at 05:37:26 AM EST
[ Parent ]
Avoid houses with granite countertops...
by asdf on Wed Mar 30th, 2011 at 07:54:41 PM EST


The Fates are kind.
by Gaianne on Wed Mar 30th, 2011 at 08:59:22 PM EST
[ Parent ]
the new global warming, complete with deniers

Index of Frank's Diaries
by Frank Schnittger (mail Frankschnittger at hot male dotty communists) on Thu Mar 31st, 2011 at 07:18:29 AM EST
See this thread.

Economics is politics by other means
by Migeru (migeru at eurotrib dot com) on Fri Apr 1st, 2011 at 05:52:53 AM EST
[ Parent ]


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