Abundance of deuterium vs tritium


by AA Institute
Tags: abundance, deuterium, tritium
BCRion
BCRion is offline
#19
Aug27-05, 10:32 AM
P: 28
Quote Quote by AA Institute
Is there such thing as a 'safe' radiation exposure limit for humans? How many rads can a human take (say an adult) before you can say for definite that he/she would suffer some kind of an ill effect? I think this was one of the debates the Apollo program managers had to contend with when planning Moon missions through the highly electrically-charged Van Allen radiation belts in the late 60s.
Depends on whether or not you believe the linear-no threshold model.

LNT observes that the dose to consequence of high radiation doses (from atomic bomb survivors mostly) varies linearly. This is extrapolated down to a zero dose, meaning that any dose is theoretically harmful. It should be noted there is no direct physical evidence of the damage due to low dose mostly because it is very difficult to measure in a very large population. It is the most conservative of the theories out there. This is the current procedure for estimating effects of radiation by pretty much every organization due to its conservatism.

Another theory says that the response is linear at high dose, but negligible at low dose, and hence a threshold. The basis being that the cellular repair mechanisms can adequately deal with the damage from low doses before any problems manifest themselves. The fact these mechanisms exist (which they do) make believe a truly linear response to be somewhat doubtful.

The most liberal theory is hormesis. This theory states that small doses of radiation may actually be beneficial. The rationale for this is that low doses of ionizing radiation actually activate cellular repair mechanisms fixing problems that would have otherwise remained unfixed. There are plenty of experiments possibly demonstrating some positive effects, but the jury is still out on this theory, although it does seem to be becoming more likely.
Morbius
Morbius is offline
#20
Aug28-05, 08:57 PM
Sci Advisor
P: 1,137
Quote Quote by BCRion
The most liberal theory is hormesis. This theory states that small doses of radiation may actually be beneficial. The rationale for this is that low doses of ionizing radiation actually activate cellular repair mechanisms fixing problems that would have otherwise remained unfixed. There are plenty of experiments possibly demonstrating some positive effects, but the jury is still out on this theory, although it does seem to be becoming more likely.
BCRion,

Check out:

http://www.llnl.gov/str/JulAug03/Wyrobek.html

which states,

"Low-Dose Exposure Can Protect
The team also discovered that the human lymphoblastoid cells exhibit what is
called an adaptive response to ionizing radiation. An extremely low dose (also
called a priming dose) appears to offer protection to the cell from a
subsequent high dose (2 grays) of ionizing radiation. ....Regulatory agencies
are convinced these effects do happen and that they may play a role in human
health.

Dr. Gregory Greenman
Physicist
Paulanddiw
Paulanddiw is offline
#21
Sep7-05, 11:52 PM
P: 96
My wife and I just came back from Montana where we spent a bunch of time sitting in the radon mines. (They used to be uranium mines). It helped my arthritis and my wife's chronic fatigue. You can see lots of old timers there visiting the mines in pretty good shape for their age.

Papers you can read on hormesis more-or-less indicate that 5 rem/yr is optimum for benefical effect of low-dose radiation. Ten rem/year is about the same a not getting any radiation at all. The value of 5 rem/yr is what the DOE allows its radiation workers in places like Hanford and Savannah River. We didn't get near this much in Montana.

Lots of anecdotal evidence supports the concept: there are LOTS of 100-year old people in Japan these days. Even more in the areas that the fallout cloud went over.


Very few people died as a result of Chernobyl. Almost all of them were the "Human Robots" that were sent in to pick up the "hot" pieces of the broken reactor. They got huge doses.

Brazil has more that a million people over 100 years old. Brazil has a very high background radiation from the "black sands" beaches which contain lots of thorium.

In the audio tape "Dead Doctors Don't Lie" he mentions a number of locations in the world where people expect to live to be 100. Most of them have high background radiation from minerals (e.g., radon) or are at high altitudes and receive lots of cosmic radiation.

People who smoke live longer if there's lots of radon in their bastements. (re. Cohn)

Let's hear from you if you have visited the mines in the US or other countries, or if otherwise.
Andrew Mason
Andrew Mason is offline
#22
Dec20-06, 11:17 PM
Sci Advisor
HW Helper
P: 6,576
Quote Quote by Paulanddiw View Post
My wife and I just came back from Montana where we spent a bunch of time sitting in the radon mines. (They used to be uranium mines). It helped my arthritis and my wife's chronic fatigue. You can see lots of old timers there visiting the mines in pretty good shape for their age.

Papers you can read on hormesis more-or-less indicate that 5 rem/yr is optimum for benefical effect of low-dose radiation. Ten rem/year is about the same a not getting any radiation at all. The value of 5 rem/yr is what the DOE allows its radiation workers in places like Hanford and Savannah River. We didn't get near this much in Montana.

Lots of anecdotal evidence supports the concept: there are LOTS of 100-year old people in Japan these days. Even more in the areas that the fallout cloud went over.


Very few people died as a result of Chernobyl. Almost all of them were the "Human Robots" that were sent in to pick up the "hot" pieces of the broken reactor. They got huge doses.

Brazil has more that a million people over 100 years old. Brazil has a very high background radiation from the "black sands" beaches which contain lots of thorium.

In the audio tape "Dead Doctors Don't Lie" he mentions a number of locations in the world where people expect to live to be 100. Most of them have high background radiation from minerals (e.g., radon) or are at high altitudes and receive lots of cosmic radiation.

People who smoke live longer if there's lots of radon in their bastements. (re. Cohn)

Let's hear from you if you have visited the mines in the US or other countries, or if otherwise.
I have started a thread in the biology section on the issue of radiation effects on humans. I was hoping that Morbius, Astronuc and other very knowledgeable posters in this section might be interested.

AM


Register to reply

Related Discussions
Hydrogen -> Tritium Chemistry 8
Hydrogen, Deuteruim, Tritium Biology, Chemistry & Other Homework 3
Half-life of tritium Biology, Chemistry & Other Homework 2
The synthesis of Deuterium-and tritium labeled compounds Biology, Chemistry & Other Homework 0
Deuterium-Tritium explosives High Energy, Nuclear, Particle Physics 5