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Author Topic: Is more radiation absorbed by the ground or the atmosphere?  (Read 3394 times)

system

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Is there a difference in the amount of radiation that is absorbed in the ground and the amount that rises into the atmosphere?
Asked by Melissa Pallin, Facebook

                                       
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« Last Edit: 13/04/2011 20:30:02 by _system »


 

Offline Boogie

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Here in Colorado, we have a lot of background radiation from naturally occuring radioactive materials (NORM). Radon gas is one of the sources of this radiation. Radon is heavy, so it collects in low lying areas and will even sink into the ground. Folks living in Colorado are urged to have their basements checked for Radon (not sure what good it will do other than cause you to freak out)... Anyway, when it rains, the rain water displaces the radon and pushes it up out of the ground where it is mixed into the air by the wind. Now, to make things even better, up in the mountains, the winds can lift radioactive dust particles (Uranium, Pitchblend, etc) off the ground and carry them into the atmosphere where Rain will wash the particles out of the air and re-deposit them on the ground. Colorado background is usually around 20uR/Hr. The rest of the USA is about 10-12 uR/Hr. One of the drawbacks of living in a mineral belt I suppose. 

So, I didn't really answer your question, but here in my neck of the woods, the ground does not absorb the radiation, but rather stores it for the next storm to pick it up and move around using the atmosphere. The ground here (mostly granite) naturally contains radioactive elements. The ground didn't absorb it, it was brought up from the depths of the earth.     

Don't worry, I've lived here all my life and co-exist peacefully with the radiation. I can't say as I've ever met a mutant or known of anyone to suffer from the radioactive effects of Colorado NORM. Some people claim that radon is good for you (google radon baths). Cat litter, some fertilizers, cigarettes, even bananas and other common items emit radiation that occured naturally. Whatever doesn't kill you only makes you stronger right?
 

Offline evan_au

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Another source of radiation is cosmic rays, which originate in somewhat mysterious energetic events in our galaxy.

People who regularly travel in airplanes (like pilots) have a higher exposure to this cosmic ray radiation, as they fly above most of earth's atmosphere. Astronauts are completely above the atmosphere, and have an even higher exposure.

Some scientific experiments like neutrino detectors have to be buried far underground in mines, to avoid the cosmic rays - the ground actually absorbs them better than the atmosphere, as it is denser. http://en.wikipedia.org/wiki/Neutrino_detector

If we are to have somewhere on earth which provides safe, long-term storage for nuclear waste, it would be best far underground, where the ground shields it from people and animals on the surface, and the geology ensures that it doesn't get into aquifers.

The cold-war flurry of atmospheric atomic bomb tests resulted in an increase in radioactive elements released into the atmosphere, which form a marker in humans alive in 1950s & 1960s. Fortunately, this was stopped by the partial nuclear test ban treaty.
http://en.wikipedia.org/wiki/Partial_Nuclear_Test_Ban_Treaty#Background
 

Offline damocles

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Folks living in Colorado are urged to have their basements checked for Radon (not sure what good it will do other than cause you to freak out)...

If you get a high reading when your basement is checked for radon, there are a few things you can do about it.
-- modify your lifestyle so that you spend the minimum of time in your basement. Certainly avoid sleeping there.
-- arrange forced air circulation and good ventilation for your basement, making sure that air from the lowest inch or two is included in the circulation pattern.
-- radon-222, which comes from the decay of radium, or, originally from the uranium that produces the radium, has a fairly short lifetime. Over the space of a week or less it decays into dusts containing radioactive lead, bismuth, and polonium. Vacuum cleaning the basement frequently might or might not be a good idea -- you would need to spend more time there to do the vacuuming, and stirring up and inhaling any dust would certainly be counter-productive!

I do not know how practical these suggestions are -- here in Australia we have relatively mild winters, and few basements. We do have areas of high radiation, but our houses are mainly designed just to slow down the wind! (i.e. they are leaky and draughty, and we usually leave a few windows open anyway.) If we live in a brick, concrete, or stone house, the background radiation we are subjected to is about double what we get if in a timber house, but even so it is a long way below a significant or dangerous level. Uranium is very widely distributed in nature, and quite abundant in mineral type building materials (1-5 parts per million).

In some areas of Australia -- mostly outback ones -- radon is a potentially significant problem, and people are advised not to camp in (usually) dry riverbeds in these areas.
 

Offline Boogie

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If we live in a brick, concrete, or stone house, the background radiation we are subjected to is about double what we get if in a timber house, but even so it is a long way below a significant or dangerous level.

Is that due to Thorium in the building materials or trapped radon in the dwelling? Just curious. We have a goodly amount of Th in our concrete.
 

Offline damocles

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If we live in a brick, concrete, or stone house, the background radiation we are subjected to is about double what we get if in a timber house, but even so it is a long way below a significant or dangerous level.

Is that due to Thorium in the building materials or trapped radon in the dwelling? Just curious. We have a goodly amount of Th in our concrete.

Due (in our case) to U mostly, and Th secondary in the building materials. But the source of all Rn is also Th or U in building materials or local rocks and soil.

U is quite a common element, and apart from its concentrated deposits in sedimentary strata, it is fairly uniformly distributed in all rocky material at a level of about 1 ppm. Th is about 3 times more globally abundant, but 5 times less active, and has a slightly more uneven distribution. It is chemically very similar to zirconium in its properties, and concentrates as a major impurity in zirconium ores and gems.
 

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