It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Thank you.
Some features of ATS will be disabled while you continue to use an ad-blocker.
You can interpret that to mean if there is a threshold, we don't know what it is. But, this doesn't mean that there isn't a threshold. Also, that was in 1950, and we've learned some things since then. This is from 1998:
donlashway
'R. M. Sievert, the famous radiologist, who had supervised radiation therapy since 1926 at the Karolinska Institute in Stockholm, pointed out at an international meeting in 1950 that `there is no known tolerance level for radiation'.[14] A tolerance level is a level below which there is no damage (sometimes called a threshold).
So, the threshold and linear (no-threshold) models are statistically equivalent if you exclude mortality data and look at cancer incidence rates.
Cancer incidence and mortality data from the atomic bomb survivors cohort has been analyzed to allow for the possibility of a threshold dose response. The same dose-response models as used in the original papers were fit to the data. The estimated cancer incidence from the fitted models over-predicted the observed cancer incidence in the lowest exposure group. This is consistent with a threshold or non-linear dose-response at low-doses. Thresholds were added to the dose-response models and the range of possible thresholds is shown for both solid tumor cancers as well as the different leukemia types. This analysis suggests that the A-bomb cancer incidence data agree more with a threshold or non-linear dose-response model than a purely linear model although the linear model is statistically equivalent.
So, the mortality data does seem to show a threshold in this study. But my position is that the jury is still out and the data is not conclusive, though I think it's just as likely there's a threshold as not based on the data I've seen. Maybe the threshold model has a slight edge as implied by this study, but I think more data is needed for a definitive conclusion about thresholds.
This observation is not found with the mortality data. For both the incidence data and the mortality data the addition of a threshold term significantly improves the fit to the linear or linear-quadratic dose response for both total leukemias and also for the leukemia subtypes of ALL, AML, and CML.
Is the radiation limit really that point which society can no longer function? Isn't it too late then ?
Let's say we have about 50,000,000,000,000 cells in our body. Let's say the single atom you speak of kills a cell. leaving only 49,999,999,999,999 cells. If you never made any new cells, that might concern you, but you do make new cells, in nearly all tissues of the body, at an amazing rate:
donlashway
reply to post by Arbitrageur
If we understand a single atom of ionizing radiation does us harm as a foundation to our understanding I think it would help.
Denying it leads to confusion.
So if the cell that died is a stomach cell, where's the harm when every cell in your stomach will die in the next 5 days anyway? The only possible harm I see from a cell death is if the cell that dies is one of the few mentioned that aren't replaced, and those areas of the body are pretty well protected thus some of the least likely to be affected by radiation.
Although people may think of their body as a fairly permanent structure, most of it is in a state of constant flux as old cells are discarded and new ones generated in their place. Each kind of tissue has its own turnover time, depending in part on the workload endured by its cells. The cells lining the stomach, as mentioned, last only five days. The red blood cells, bruised and battered after traveling nearly 1,000 miles through the maze of the body's circulatory system, last only 120 days or so on average before being dispatched to their graveyard in the spleen.
The epidermis, or surface layer of the skin, is recycled every two weeks or so. The reason for the quick replacement is that "this is the body's saran wrap, and it can be easily damaged by scratching, solvents, wear and tear," said Elaine Fuchs, an expert on the skin's stem cells at the Rockefeller University.
As for the liver, the detoxifier of all the natural plant poisons and drugs that pass a person's lips, its life on the chemical-warfare front is quite short. An adult human liver probably has a turnover time of 300 to 500 days, said Markus Grompe, an expert on the liver's stem cells at the Oregon Health & Science University.
Other tissues have lifetimes measured in years, not days, but are still far from permanent. Even the bones endure nonstop makeover. The entire human skeleton is thought to be replaced every 10 years or so in adults, as twin construction crews of bone-dissolving and bone-rebuilding cells combine to remodel it.
About the only pieces of the body that last a lifetime, on present evidence, seem to be the neurons of the cerebral cortex, the inner lens cells of the eye and perhaps the muscle cells of the heart.
mikell
reply to post by OOOOOO
Got a link for the 50k spill at Fermi I don't seem to find anything.
donlashway
reply to post by Arbitrageur
Yea, that's where I want to start one ionizing radiation particle; alpha, gama or beta causing damage.
It's like saying peeing in the pacific ocean raises the level of the ocean.
donlashway
reply to post by Arbitrageur
Yea, that's where I want to start one ionizing radiation particle; alpha, gama or beta causing damage.
To this we can both agree?
My friend, you have stated in different words the concept of a threshold, when you say this. While some people are arguing that there is no threshold, I'm somewhat neutral on this issue, saying that there is some evidence for a threshold, but it's not well defined or conclusive yet due to lack of evidence and the difficulty of measuring small effects.
OOOOOO
If it is in excess amount of damaged cells
OOOOOO
I was told it was really a beer can, which sound more plausible...
Bedlam
reply to post by RickinVa
Add four -
tracks across the cell, the cell is unable to repair the damage, fails to detect the damage, and dies during mitosis
tracks across the cell, the cell is unable to repair the damage but detects that it is damaged, apoptosis is triggered
tracks across the cell, the cell is unable to repair the damage, does not detect it, undergoes mitosis properly, but no longer fulfills its function. It does not become "immortalized" and dies out after it hits its Hayflick limit.
tracks across the cell, is unable to repair the damage, does not undergo apoptosis, and enables the genes to produce telomerase, thus becoming "immortal", and begins to replicate without check. That's the only one where you get 'cancer' per se.
edit on 22-1-2014 by Bedlam because: (no reason given)
Based on current statistics the discharge from Fukushima
is less than half the exposure
“we all get from the global consumption of bananas,”
Tim Worstall quipped,
pointing out we eat the radioactive potassium in that fruit
Tepco said Wednesday it detected 200,000 becquerels per liter of beta ray-emitting radioactive substances, including strontium-90, far above the legal limit of 30 becquerels per liter, as well as cesium-134 and -137, both within their legal limits.
***ATTENTION***
Personal attacks and off-topic remarks are not conducive to a healthy conversation. Further violations will result in potential posting bans.
Please discuss the topic, not each other.
~Tenth
ATS Super Mod