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The website I linked is the federal agency for nuclear safety. Depends entirely what you mean by "dangerous levels". It is contaminated enough, that mushrooms

by _ph_ 8y ago

The website I linked is the federal agency for nuclear safety. Depends entirely what you mean by "dangerous levels". It is contaminated enough, that mushrooms from the forests are not allowed to be sold as food. Yes, a single serving won't have a significant impact on your health, but it is recommended not to eat much of them. The situation is worse with some wild boar, which eat a lot of those mushrooms and accumulate cesioum over many years. And perhaps a relevant information: the Bavarian forests are about 600 miles from the Chernobyl site.

godelski 8y ago
Dangerous levels has an exact definition. The EU sets them at 20mSv/yr. To put that in perspective, 1Sv is equivalent to a 5% increase in chance of getting cancer during your lifetime (granted, that dose needs to be spread out). So you can see that they keep it REALLY low. Extra safety is used because they use the linear no-threshold model. Yes, the model is linear so you can extrapolate easily. Those levels that acidburn was talking about, mentioned in the article, are REALLY low. The reason government is overly cautious with radiation is 1) fear 2) you can't control sources so you say "if we set this threshold we'll never put anyone in danger even if they take in large amounts from other sources that we can't control." Remember, each of those 200g of mushrooms (which looks like an upper limit of measurement, not average nor lower) is like a 5hr plane ride in a non-northern route (8uSv). People take plane rides worse than that several times a week and are safe. (see below for ridiculousness of this "danger") You also realize that over time these things degrade, right? Not just by radioactive decay, but because organisms and chemical reactions break down the radioactive materials. You seem to be implying that over the many years it is getting worse. Which is just untrue (and frankly should not pass a smell test). Side note: 200g mushrooms = 0.008mSv (upper limit) 20mSv/(0.008mSv)*200g = 500kg of mushrooms. That's how many you would need to eat in a year to get to the legal limit. Let's be real here, this is just a ridiculous amount of mushrooms that you have to consume within a year. That's over a kilo a day. Note that this limit used to also be 50mSv for radiation workers. Astronauts are allowed much more. tldr: Trust the domain expert over some article you read on the internet.
- _ph_ 8y ago
  >You also realize that over time these things degrade, right? Yes, with a half-time of 30 years. >Not just by radioactive decay, but because organisms and chemical reactions break down the radioactive materials. We are talking about radioactive isotopes. Nothing short of a nuclear reaction is going to "break them down", certainly not organisms or chemical reactions >You seem to be implying that over the many years it is getting worse. Which is just untrue (and frankly should not pass a smell test). No, I did no such thing. I said that wild boar is contaminated worse as they keep eating mushrooms for years while each mushroom only has a couple of days to aggregate radioactive isotopes. >tldr: Trust the domain expert over some article you read on the internet. It wasn't "some article" I quoted, but the official information of the federal office for nuclear safety.
  - godelski 8y ago
    First off, fix your formatting. This is hard to read. You need two new lines to form one in HN, but it kinda looks like you already know that. > Yes, with a half-time of 30 years. Biological half lives tend to be A LOT shorter. It is something like 90 days in humans (for Cesium). There's also the uptake rate, which IIRC is about 10%. > Nothing short of a nuclear reaction is going to "break them down", certainly not organisms or chemical reactions Oh, sorry. I didn't realize that radiation means that electrons will no longer form bonds. That's really interesting. But I have a question. This being true, can you tell me how we get solids? Or are you saying that radioactive materials can only bind to other materials with similar radioactive properties? I can tell you that I never learned this in any of many physics classes nor while I was working as a radiation researcher. If this is a new study done by you I'm excited to see you win the Nobel. Really groundbreaking work. > No, I did no such thing. I said that wild boar is contaminated worse as they keep eating mushrooms for years while each mushroom only has a couple of days to aggregate radioactive isotopes. 10% uptake, shorter biological half life. This isn't a system with positive feedback. The more degrees the more dilution. The Cs is in the ground, mushrooms eat that (1 degree), boars eat that (2 degrees), humans eat that (3 degrees). Minimum. We are assuming that the Cs is just laying nicely and not being diluted by worms and bugs before it is absorbed by the mushrooms. > It wasn't "some article" I quoted, but the official information of the federal office for nuclear safety. You're pulling from much more than that article. Your domain experts in this thread are breaking down that official information and explaining what things mean (note, neither of us have disputed it). For example, what is a Sievert? How dangerous is it? How much is safe? Can this be explained in a way without years of studying atomic physics and nuclear medicine? What you're doing is reading that and saying "Look how dangerous this stuff is!" We're looking at it and saying "Ah cool, so as long as I don't eat 500 kilos of wild mushrooms in a year I'll be good". There's a big difference between these two points of view. But again, I'm not disputing what is in that documentation. I am drawing from it to demonstrate how safe things are.

by _ph_ 8y ago

godelski 8y ago

Dangerous levels has an exact definition. The EU sets them at 20mSv/yr. To put that in perspective, 1Sv is equivalent to a 5% increase in chance of getting cancer during your lifetime (granted, that dose needs to be spread out). So you can see that they keep it REALLY low. Extra safety is used because they use the linear no-threshold model. Yes, the model is linear so you can extrapolate easily. Those levels that acidburn was talking about, mentioned in the article, are REALLY low. The reason government is overly cautious with radiation is 1) fear 2) you can't control sources so you say "if we set this threshold we'll never put anyone in danger even if they take in large amounts from other sources that we can't control." Remember, each of those 200g of mushrooms (which looks like an upper limit of measurement, not average nor lower) is like a 5hr plane ride in a non-northern route (8uSv). People take plane rides worse than that several times a week and are safe. (see below for ridiculousness of this "danger") You also realize that over time these things degrade, right? Not just by radioactive decay, but because organisms and chemical reactions break down the radioactive materials. You seem to be implying that over the many years it is getting worse. Which is just untrue (and frankly should not pass a smell test). Side note: 200g mushrooms = 0.008mSv (upper limit) 20mSv/(0.008mSv)*200g = 500kg of mushrooms. That's how many you would need to eat in a year to get to the legal limit. Let's be real here, this is just a ridiculous amount of mushrooms that you have to consume within a year. That's over a kilo a day. Note that this limit used to also be 50mSv for radiation workers. Astronauts are allowed much more. tldr: Trust the domain expert over some article you read on the internet.

_ph_ 8y ago
>You also realize that over time these things degrade, right? Yes, with a half-time of 30 years. >Not just by radioactive decay, but because organisms and chemical reactions break down the radioactive materials. We are talking about radioactive isotopes. Nothing short of a nuclear reaction is going to "break them down", certainly not organisms or chemical reactions >You seem to be implying that over the many years it is getting worse. Which is just untrue (and frankly should not pass a smell test). No, I did no such thing. I said that wild boar is contaminated worse as they keep eating mushrooms for years while each mushroom only has a couple of days to aggregate radioactive isotopes. >tldr: Trust the domain expert over some article you read on the internet. It wasn't "some article" I quoted, but the official information of the federal office for nuclear safety.
- godelski 8y ago
  First off, fix your formatting. This is hard to read. You need two new lines to form one in HN, but it kinda looks like you already know that. > Yes, with a half-time of 30 years. Biological half lives tend to be A LOT shorter. It is something like 90 days in humans (for Cesium). There's also the uptake rate, which IIRC is about 10%. > Nothing short of a nuclear reaction is going to "break them down", certainly not organisms or chemical reactions Oh, sorry. I didn't realize that radiation means that electrons will no longer form bonds. That's really interesting. But I have a question. This being true, can you tell me how we get solids? Or are you saying that radioactive materials can only bind to other materials with similar radioactive properties? I can tell you that I never learned this in any of many physics classes nor while I was working as a radiation researcher. If this is a new study done by you I'm excited to see you win the Nobel. Really groundbreaking work. > No, I did no such thing. I said that wild boar is contaminated worse as they keep eating mushrooms for years while each mushroom only has a couple of days to aggregate radioactive isotopes. 10% uptake, shorter biological half life. This isn't a system with positive feedback. The more degrees the more dilution. The Cs is in the ground, mushrooms eat that (1 degree), boars eat that (2 degrees), humans eat that (3 degrees). Minimum. We are assuming that the Cs is just laying nicely and not being diluted by worms and bugs before it is absorbed by the mushrooms. > It wasn't "some article" I quoted, but the official information of the federal office for nuclear safety. You're pulling from much more than that article. Your domain experts in this thread are breaking down that official information and explaining what things mean (note, neither of us have disputed it). For example, what is a Sievert? How dangerous is it? How much is safe? Can this be explained in a way without years of studying atomic physics and nuclear medicine? What you're doing is reading that and saying "Look how dangerous this stuff is!" We're looking at it and saying "Ah cool, so as long as I don't eat 500 kilos of wild mushrooms in a year I'll be good". There's a big difference between these two points of view. But again, I'm not disputing what is in that documentation. I am drawing from it to demonstrate how safe things are.