I've heard this before, but this really isn't how radiation works.
The higher dosages you're exposed to and the longer, the more likely the negative affects.
But it's strangely additive, like getting wet. Which is a poor analogy but the most fitting I can think of.
You might get "more wet" by standing in the rain than getting splashed with puddle, sure, but you're still increasing your "wet-ness" by not drying out before getting splashed.
Only this wet gives you cancer if you stay wet too long, or get too wet.
Yes, actually it is, at least as far as the risks of security scanners vs. flying are concerned. The radiation you get exposed to in an airplane at altitude is largely ionizing radiation. The radiation you get exposed to in security scanners is not. So in addition to the much shorter time of exposure, and hence the much smaller overall dose, the type of radiation in security scanners is much, much less damaging to your body even at comparable doses.
> it's strangely additive
I'm not sure what you mean by this, but if you mean that the additional radiation from security scanners is somehow "additive" with the radiation you are exposed to in the airplane, no, that's not correct. They're different types of radiation and do different things to your body. There's no cumulative effect between them.
Truthfully, the amount of radiation you are exposed to does accumulate its negative affects, we certainly consider it as such for every work environment for a reason.
You are confident in this, and more eloquent than me at 2am, whoever I cannot let that falsehood stand.
As far as ionising radiation goes, if its ionising then its ionising, there’s not “different types”- however the parent is correct that millimetre waves do not penetrate the skin and are considered non-ionising
What kind of radiation? If you mean ionizing radiation, the evidence, as far as I know, is mixed; some indicates there is buildup over time, some indicates that there are threshold effects and single doses below threshold, separated in time, do not accumulate. We do have lifetime dose limits as well as single exposure dose limits for such radiation because the evidence is mixed and we can't rule out that there are accumulation effects.
But if you mean non-ionizing radiation, such as is used in the millimeter wave security scanners, there is no evidence of accumulation of effects over time from low doses (i.e., doses that do not cause immediate harmful effects) that I'm aware of. Do you know of any?
It's not a cause for concern, no. Tons of people live and work at high elevations, in granite buildings, and many other places where the background ionizing radiation level is far higher than normal.
You'd do well to consult this chart: <https://xkcd.com/radiation/>, paying particular attention to the expected radiation exposure from background sources, comparing that to the "Lowest one-year dose clearly linked to increased cancer risk" amount, and also noting that the repeated phrase "All the doses in the $COLOR chart combined".
You'd also do well to clear fifteen or thirty minutes from your day and read this letter, published in 1997: <https://radiationeffects.org/wp-content/uploads/2015/05/Rock...>. Do take it slow and don't skim. It's an essay written to be read, rather than for SEO, so you absolutely will miss important details if you skim.
Not that it isn’t additive, it’s that people don’t care like they don’t care that eating a banana vs eating another item [0].
And in the US, backscatter X-rays have found continued use in jails and prisons. There is actually one that is used in Cook County (Chicago) that is a conveyor belt you stand on to get a full 5 seconds of X-ray exposure. Opting out of the prison scanner may be possible depending on your circumstances, but undoubtedly more difficult