3 ms·

> You need 3kx higher levels to even approach danger levels The article almost starts talking about bio-concentration, but veers away after talking about findi

> You need 3kx higher levels to even approach danger levels The article almost starts talking about bio-concentration, but veers away after talking about findings in seals. Just because the open water concentration is well below safe levels does not mean that everything is hunky-dory. Cesium is an element that can be bio-concentrated, and then consumed as part of the food chain. It's not a simple thing to say this is "completely safe".

godelski 8y ago
> It's not a simple thing to say this is "completely safe". At those levels, yeah, yeah it is. The biological half-life is about 70 days. There's also the issue of uptake. IIRC for 137Cs it is about 10%. So each time that radiation travels along that food chain only about 10% of 137Cs from food is taken up. You can see how fast that's going to dilute.
- jhayward 8y ago
  > The biological half-life is about 70 days. You can't make that claim without knowing the species and the conditions. For instance, the study [1] below finds a biological half-life 4 times longer than that in rockfish in coastal waters. As I said, it's not that simple. [1] https://www.sciencedirect.com/science/article/pii/S0265931X15300758 https://www.sciencedirect.com/science/article/pii/S0265931X1...
  - godelski 8y ago
    The problem I'm taking with your comment is that while technically you're correct, it isn't meaningful. We can always argue about semantics. ALWAYS. Every subject is so nuanced that you can spend hours upon hours better refining things. Hell, I've seen books on o-rings that are several times larger than graduate level textbooks on classical mechanics. The point is that there's a certain amount of refinement that is "good enough". Here's an example, using the paper you linked. They say that there is no significant difference between biological half-lives in the different sexes of rock fish. They show that males have 274+-39 days and females have 253+-37 (P=0.16). To be publishable in many journals you have to have p<=0.05. And there's a 15% error on those numbers (most likely due to small sample size). But we don't just throw the results out because they aren't "exact". In our case at hand, we're talking about a radiation level that is __EXTREMELY__ small. Unless we want to write a textbook we have to generalize. Given that we're on a forum and not an academic setting, this should be expected. Convoluting the subject to make a point that you can say with certainty that the vast majority of marine life will not be significantly affected by these levels of radiation. Again, this is because the quantities are VERY VERY small. And if you don't believe me, read the freaking report [0]. We're talking about levels that are only slightly above background levels. We're talking about a possible anomaly considering that several samples previously were still below background levels. This is the reason we can make this generalization of "yes it is that simple". We can restate the report as "radiation approximately maintains background levels." If we read it this way it is clear that nothing would likely be in danger. That's why I can make this claim with high certainty. And I'm not having any of your fear mongering when the case is trivially provable. tldr: Don't be "fun at parties" and read the report if you want to sound smart. [0] https://seagrant.uaf.edu/bookstore/pubs/MAB-72.html https://seagrant.uaf.edu/bookstore/pubs/MAB-72.html

godelski 8y ago

> It's not a simple thing to say this is "completely safe". At those levels, yeah, yeah it is. The biological half-life is about 70 days. There's also the issue of uptake. IIRC for 137Cs it is about 10%. So each time that radiation travels along that food chain only about 10% of 137Cs from food is taken up. You can see how fast that's going to dilute.

jhayward 8y ago
> The biological half-life is about 70 days. You can't make that claim without knowing the species and the conditions. For instance, the study [1] below finds a biological half-life 4 times longer than that in rockfish in coastal waters. As I said, it's not that simple. [1] https://www.sciencedirect.com/science/article/pii/S0265931X15300758 https://www.sciencedirect.com/science/article/pii/S0265931X1...
- godelski 8y ago
  The problem I'm taking with your comment is that while technically you're correct, it isn't meaningful. We can always argue about semantics. ALWAYS. Every subject is so nuanced that you can spend hours upon hours better refining things. Hell, I've seen books on o-rings that are several times larger than graduate level textbooks on classical mechanics. The point is that there's a certain amount of refinement that is "good enough". Here's an example, using the paper you linked. They say that there is no significant difference between biological half-lives in the different sexes of rock fish. They show that males have 274+-39 days and females have 253+-37 (P=0.16). To be publishable in many journals you have to have p<=0.05. And there's a 15% error on those numbers (most likely due to small sample size). But we don't just throw the results out because they aren't "exact". In our case at hand, we're talking about a radiation level that is __EXTREMELY__ small. Unless we want to write a textbook we have to generalize. Given that we're on a forum and not an academic setting, this should be expected. Convoluting the subject to make a point that you can say with certainty that the vast majority of marine life will not be significantly affected by these levels of radiation. Again, this is because the quantities are VERY VERY small. And if you don't believe me, read the freaking report [0]. We're talking about levels that are only slightly above background levels. We're talking about a possible anomaly considering that several samples previously were still below background levels. This is the reason we can make this generalization of "yes it is that simple". We can restate the report as "radiation approximately maintains background levels." If we read it this way it is clear that nothing would likely be in danger. That's why I can make this claim with high certainty. And I'm not having any of your fear mongering when the case is trivially provable. tldr: Don't be "fun at parties" and read the report if you want to sound smart. [0] https://seagrant.uaf.edu/bookstore/pubs/MAB-72.html https://seagrant.uaf.edu/bookstore/pubs/MAB-72.html