5 ms·
> the Navy explained to me that it was balanced out because I was underwater and not receiving radiation exposure from the sun With the greatest respect to the
by traceroute66 5y ago
> the Navy explained to me that it was balanced out because I was underwater and not receiving radiation exposure from the sun
With the greatest respect to the Navy, I smell more fish than in the seas that submarine travelled through.
My non-scientific understanding is that sun exposure is UV radiation exposure which causes skin melanoma. Meanwhile with nuclear reactors, UV is not the problem and the problem with exposure goes deeper than skin melanoma.
My feeling is you received a standardised "policy explanation" rather than an entirely scientific one. Happy to be proven wrong with links to scientific fact though !
- lorenzhs 5y agoCosmic background radiation is a thing and water is really good at blocking it, so it's not complete bullshit. Of course, without knowing what dose the GP received, it's impossible to say whether it's a comparable dose to what they would have received on the surface - but it's plausible.
- traceroute66 5y ago> Cosmic background radiation is a thing Indeed. But isn't it really only "a thing" for airline pilots, cabin crew and a few unfortunate people at ground level who happen to live/work high-altitude on mountains or somewhere lower down with the wrong kind of rocks ?
- mlyle 5y agoSee https://news.ycombinator.com/item?id=29761595 https://news.ycombinator.com/item?id=29761595
- traceroute66 5y agoCool, thanks for that. I didn't realise XKCD actually posted serious stuff. ;-)
- trenchgun 5y agoAlso: https://what-if.xkcd.com/29/ https://what-if.xkcd.com/29/
- _ph_ 5y agoDepends how you look at it. Cosmic radiation might not be extremely high level on the sea level, but it is a thing. So the total radiation dosis in a nuclear submarine might equal or even be less than on the surface. Fun story: as part of my physics education we did an experiment on the cosmic radiation with a "radiation" telescope. That were 2 Geiger counters with a logic that only registered events which basically occured in both counters at the same time. That made the observation reasonably detectable and you could "see" the sun with this. This experiment was conducted indoors, just on the top floor of the building. We had about 1 event/second, our bodies would be getting a similar dosis all the time.
- beowulfey 5y agoNo, it is a gradient, with more exposure happening higher up. Radiation damage is considered “additive” over your lifetime. So if you are somewhere with less background radiation, you can receive more radiation from other sources and still be considered within “safe” limits. This is the basis for the policy mentioned.
- goodpoint 5y agoThe idea that radiation exposure can be "balanced out" is very sketchy. Reminds me of https://en.wikipedia.org/wiki/Risk_compensation https://en.wikipedia.org/wiki/Risk_compensation
- ch4s3 5y agoI think they just poorly explained that his exposure in the sub was lower than background radiation levels on the sea surface. You get more rads living in Colorado for a year than anyone would get working in a nuclear power plant for a year at sea level.
- doodlebugging 5y ago(https://spaceweather.com/ https://spaceweather.com/) There is some good information about the relative exposure levels to cosmic radiation that one can expect to encounter on this site. They have been doing balloon launches and measuring in-flight levels for quite a while now.
- spfzero 5y agoNot to mention radiation from the ground, which can be significant in some locations.
- tapland 5y agoIt's true for nuclear reactor buildings where the walls block more background radiation as well. I'd you are worried, avoid plane flights. Handy simplified chart: https://xkcd.com/radiation/ https://xkcd.com/radiation/
- ch4s3 5y agoApparently you should also avoid Finland which averages 0.11uSv.
- jabl 5y agoPer the Finnish radiation protection agency the average dose is 5.9 mSv/y: https://www.stuk.fi/en/web/en/topics/what-is-radiation/the-average-radiation-dose-in-finland https://www.stuk.fi/en/web/en/topics/what-is-radiation/the-a... A large chunk of that average dose, 4 mSv, is from radon, where the dose varies a lot depending on where you live, and if you live in such a radon-prone location, whether you have sufficient ventilation in your house.
- trenchgun 5y agoRadon should not be that bad, unless combined with smoking. Source: live in Finland and have read the health authority info on subject.
- jabl 5y agoYes, you're correct. The page I linked to has this to say: "For example, the health risk caused by radon is estimated on the basis of epidemiologic examinations, not the effective dose. Every year, an average of 280 Finns die from lung cancer caused by radon. Of these cases, 240 deaths are induced by smoking in addition to radon." So they're not actually measuring an average 4 mSv/y dose from radon, but rather going the other way, that is that 280 yearly deaths from radon would be consistent with an average dose of 4 mSv/y (assuming LNT, presumably).
- mlyle 5y agoXKCD has a really good chart: https://xkcd.com/radiation/ https://xkcd.com/radiation/ Humans receive about 3-4 mSv per year of background radiation on average. Some of this is from radioactive decay, and some from cosmic radiation. Being underwater much of the year might shave 1-2 mSv off this. Civilian radiation workers can receive, by regulation, doses up to 50 mSv per year. Typical reactor workers in the civilian energy sector get a couple mSv per year of dose. It is plausible that he was close to breakeven. 100mSv/year is the lowest dose that has shown a clear link to increased cancer risk.
- amelius 5y agoSeems strange that there is only a factor of 2 between maximum allowed dose and lowest dose linked to cancer.
- gkop 5y agoWould you say more? What that suggests to me is the authority responsible for setting the max allowed said “Well let’s keep it below the threshold linked to cancer, reduce it by half for safety factor, and call it a day”. IE they chose one of the simplest possible approaches- doesn’t seem surprising, but I am probably missing your point.
- KarlKemp 5y agoThere are any number of substances where there’s little doubt that they can cause cancer even at minuscule doses, just at similarly low rates. Get enough data and you will find that a single whiff of tobacco smoke (or any other smoke) can cause cancer. The “lowest dose linked to cancer” is the result of our ability to measure such effects, not anything intrinsic to the harm these substances do. That’s specific for cancer. For other forms of toxicity, the concept of “maximum safe dosage” does make sense when the dose/effect relationship is not linear. Pharmaceuticals, for example, can be entirely benign at small dosages yet lethal if you overdose.
- fallingknife 5y agoBut we can still set a significance threshold. Your point applies equally to radiation exposure flying on an airplane but we don't worry about the cancer odds from a single flight since it's lower than the (already miniscule) odds of crashing.
- mwattsun 5y agoYou're probably right. I thought the same thing, but since I didn't care I didn't pursue it. I would have cared if the scuttlebutt was that people were getting sick and dying, but that was not the case. Sub sailors were not dying in an detectable numbers.
- elevenoh 5y agoWell put. I'm amazed at some of the idioms I hear about comparable radiation doses. These idioms often completely overlook things like dose duration.