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X rays (slrpnk.net)
submitted 5 months ago by to c/memes@lemmy.world
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[–] 5 points 5 months ago (3 children)

The reasoning behind abandoning ALARA isn't particularly strong; it's based on pragmatism and economics of risk, not the underlying biology and chemistry of ionizing radiation exposure. Linear No Threshold is still one of the more conservative models that accurately depicts the impact of ionizing radiation on the underlying biology of adducts, double strand breaks, and associated repair mechanisms.

We're already in a shooting gallery of radiation exposure due to solar and terrestrial sources; controlling some radiation sources won't be worth the cost, but that's where reasonable comes in.

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  • [–] 0 points 5 months ago* (2 children)

    No, LNT is not accurate. It's accurate at high levels of exposure, not not low. In fact, there is growing evidence that low levels of exposure actually have health benefits (this is not saying to go get irradiated, as we don't have enough data).

    LNT works under the assumption there is no biological repair mechanism. As you say, we are in a shooting gallery of radiation exposure. If we did have a way to handle low levels of radiation exposure then we wouldn't be alive. LNT causes more harm than it does good, because it causes over-reactions. It's the same reason breast cancer screening isn't recommended below a certain age. At a certain point, prevention does more damage than it helps because what you're preventing is so infrequent that the checks are more harmful than the chance you actually prevent something.

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  • [–] 1 point 5 months ago (1 child)

    LNT does not assume that there isn't a repair mechanism. It assumes that the repair mechanism has a constant failure rate. That's a pretty good match for the primary biological process involved.

    All of the studies I'm aware of looking at lower dose thresholds for radiation occur on timescales and in situations where the benefits of selection due to mutations overrides the negative effects of mutations on cancers. They aren't actually measuring lifetime cancer risk on an organism level. (If a study is talking about comparing sieverts instead of doses of a specific kind of radiation, it's also suspect.)

    It's theoretically possible to have a positive effect on an organism level, but that involves much more complicated biological mechanims like immunity and epigenetics which aren't as easily modeled or as well understood. Moreover, they also have the capability of being supra-linear at low rates of DNA damage.

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  • [–] 1 point 5 months ago

    LNT does not assume that there isn't a repair mechanism. It assumes that the repair mechanism has a constant failure rate. That's a pretty good match for the primary biological process involved.

    It really isn't a good match. It makes no sense. It does not assume there's a repair mechanism, as it's cumulative over a lifetime. If you include a repair mechanism then exposure rate needs to be included, not all time total exposure. We have models that take this into account and are more accurate at pridicting cancer risk.

    I don't know if you even know what you're talking about if you don't know this. Even the Wikipedia page for linear no threshold tells you this in the first paragraph.

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