3 ms·

That is also assuming that cancer treatments won't get better with time, right? Also, "Linear no-threshold theory of radiation safety" sounds strange? For e.g.

by berntb 10y ago

That is also assuming that cancer treatments won't get better with time, right? Also, "Linear no-threshold theory of radiation safety" sounds strange? For e.g. gamma radiation, cancer risk is very far from linearly correlated. Edit: Iirc from course literature a long time ago, a DNA break from gamma radiation is repairable. So for a permanent mutation to happen, there had to be two hits of radiation close together before the first damage could be repaired. (Also, as links were given in comments, the self repair functions seem to be healthy. So when radiation forces a start of the helpful self repair mechanism, the end result for low radiation levels might be better for health if the repair mechanism adds more to health than the radiation harms.)

maxerickson 10y ago
It isn't strange, it's widely discussed. It is more conservative than other proposed models in the sense that it ascribes the more danger to low dose exposures. A common approach when considering safety is to look at the result of the most conservative information available.
jessriedel 10y ago
Well, the linear assumption is only applied in the limit of low doses. The problem is that for many large-population radiation exposures, the total release is dominated by very small dosages to very large numbers of people, and we're not able to extract the dosage-response curve from data for arbitrarily small dosages. (If I get one extra gamma ray, does my risk of cancer rise by 10^-10? Hard to check...) There are alternative theories that small amounts of radiation are neutral or even positive since they are within the natural radiation background and the body has various mutation repair machinery. https://en.wikipedia.org/wiki/Radiation_hormesis https://en.wikipedia.org/wiki/Radiation_hormesis However, these theories tend to be emphasized by nuclear-power proponents, and of course the data doesn't say. In any case, I believe the linear no-threshold model is consistent with the data and is generally considered conservative (i.e., an upper limit on the number of ill-effects).
OscarCunningham 10y ago
For high doses in a short time the risk is non-linear. But in Fukishima's case the dose is low and over a long period of time, and this is suspected to be linear. The competing theories are that lower doses of radiation have sub-linear risk, so if the linear model is wrong then people affected by the disaster are likely to be better off.
Iv 10y ago
> That is also assuming that cancer treatments won't get better with time, right? At one point I tried to research what number we had about the real impact of Chernobyl (living a bit close to Fukushima, I was interested personally). A "funny" thing about it is that in several places, this was a time when early cancer detection was improving a lot, and thyroid cancer (the most common one caused by radiations) prognosis benefits a lot from early detection (curable with 99% of chance if caught early on). In the region I was interested in (France and Italy), the improvement in cancer treatment was really great and much higher than the negative impact from the radioactive cloud. It would be hard to tell the difference between a small delay in updating medical practices locally compared to national level and an increased risk due to radiation. Some people even hypothesize that radiation scare may have make more people do early cancer detection test and that it could have actually lowered the number of cancer death. Which would be pretty ironic.

by berntb 10y ago

maxerickson 10y ago

It isn't strange, it's widely discussed. It is more conservative than other proposed models in the sense that it ascribes the more danger to low dose exposures. A common approach when considering safety is to look at the result of the most conservative information available.

jessriedel 10y ago

Well, the linear assumption is only applied in the limit of low doses. The problem is that for many large-population radiation exposures, the total release is dominated by very small dosages to very large numbers of people, and we're not able to extract the dosage-response curve from data for arbitrarily small dosages. (If I get one extra gamma ray, does my risk of cancer rise by 10^-10? Hard to check...) There are alternative theories that small amounts of radiation are neutral or even positive since they are within the natural radiation background and the body has various mutation repair machinery. https://en.wikipedia.org/wiki/Radiation_hormesis https://en.wikipedia.org/wiki/Radiation_hormesis However, these theories tend to be emphasized by nuclear-power proponents, and of course the data doesn't say. In any case, I believe the linear no-threshold model is consistent with the data and is generally considered conservative (i.e., an upper limit on the number of ill-effects).

OscarCunningham 10y ago

For high doses in a short time the risk is non-linear. But in Fukishima's case the dose is low and over a long period of time, and this is suspected to be linear. The competing theories are that lower doses of radiation have sub-linear risk, so if the linear model is wrong then people affected by the disaster are likely to be better off.

Iv 10y ago

> That is also assuming that cancer treatments won't get better with time, right? At one point I tried to research what number we had about the real impact of Chernobyl (living a bit close to Fukushima, I was interested personally). A "funny" thing about it is that in several places, this was a time when early cancer detection was improving a lot, and thyroid cancer (the most common one caused by radiations) prognosis benefits a lot from early detection (curable with 99% of chance if caught early on). In the region I was interested in (France and Italy), the improvement in cancer treatment was really great and much higher than the negative impact from the radioactive cloud. It would be hard to tell the difference between a small delay in updating medical practices locally compared to national level and an increased risk due to radiation. Some people even hypothesize that radiation scare may have make more people do early cancer detection test and that it could have actually lowered the number of cancer death. Which would be pretty ironic.