It’s unlikely that someone outside a nuclear profession would be exposed to that level of radiation, but Hahn had a record of playing with isotopes to the point of creating a Superfund site in mom’s backyard. That would be a special case.
Also, more than just submarines have nuclear power plants these days.
In any case, I’m guessin Hahn couldn’t pass psychological screening for submarine duty even aside from the radiation issue.
I’m not sure there is actually any useful way of testing for prior exposure. You could test for the presence of radioactive isotopes in the blood, but this is not going to indicate prior exposure to radiation, only that you have breathed or ingested stuff, and recently.You would need to find DNA damage, and that is basically impossible.
Running them under a gamma camera might find a hot spot where a bit of radioactive dust has lodged, but you would need to be lucky, and that still won’t find alpha and beta emitters. A whole body CT scan might turn up thus far undiagnosed tumours, but even then they would only become visible pretty late in the game.
Anyone who has a known history of exposure to an occupational hazard will typically be considered poorly for a job that involves further exposure to the hazard. It makes for a really messy legal problem if they later develop health issues. You often have no way of base-lining the current situation, and will find yourself in an impossible situation if you get sued. Employing a guy to help tend a reactor known to have spend his youth inhaling radioactive dust in his shed is not smart. If he develops a cancer especially one linked to radiation exposure, you are going to find things very messy. Better to keep him away from the hot stuff.
In other words, the title, The Radioactive Boy Scout, is a bit of a misnomer. Hahn himself was not radioactive in the sense that you could pass a Geiger counter over his body and get a lot of ticking. He was just exposed to radiation, and possibly absorbed a few isotopes, though he made a fair effort not to. That tends to be hard to measure conclusively after the fact.
And in answer to the question I posed:
Very sad. But not surprising, I guess. Does cocaine abuse cause the same kind of picking-at-your-skin-resulting-in-facial-sores that we usually associate with methamphetamine users?
Further evidence that radiation is not as dangerous as the popular hysterical opinion holds it to be. The occupational regulations and limits are absurdly conservative. The way a lot of people talk about mild radioactive sources, like radon, you would think that somebody was trying to make them sleep with 10 pounds of plutonium on their chest.
Yeah, you don’t want to be ingesting alpha-emitters…
Being “exposed” to radiation is one thing, getting radioactive particles inside your body is something else.
You can’t really draw any conclusions about radiation hazards from this case, because he died very young. Maybe he was due to die of cancer by age 50, if he hadn’t died of alcohol poisoning before 40.
How is this man’s early death of other cause evidence that radiation is not dangerous?
There are people convinced that radiation will kill you very rapidly, or given you cancer in a very short time period. Obviously, that did not happen in his case. It’s not evidence that radiation is harmless, it’s evidence it’s not as harmful as some people on the fringe believe it to be.
“The poison is in the dose” applies to radiological exposure, too. 
Digging around, his father admitted that his son died of alcohol poisoning, which leaves the issue of radiological injury moot. Or at worst, indeterminate.
It looks like the medical examiner determined that he died of “intoxication by the combined effects of alcohol, fentanyl, and diphenhydramine.” The only note about anything radiation related was that he had a “history of cutaneous radiation injury,” but his father said that referred to a burn scar on one of his wrists from when he was attempting to build his breeder reactor.
Well yes - the fact that he didn’t turn green and die as a teenager is the evidence that not all cases of radiation exposure are alike. The fact that he died of some other cause is not evidence of anything related to radiation.
Yeah, but the general public opinion is that all radiation accidents are of the same severity as Louis Slotin or Chernobyl (depending on scale). The reality is that if you don’t die a slow agonizing death within a month of the exposure, and you haven’t ingested any emitters, you’re statistically likely to get cancer five years or so sooner than the average. Hell, airline pilots get WAY more ionizing radiation than is allowed for nuclear plant workers (in the form of cosmic rays), and they’re not dropping like flies. Just like the stable heavy metals, it’s really only terribad if you get it in you. A lot of the media frenzy over, say, depleted uranium ammunition and thorium lantern mantles is because the factory is a superfund site and the end user breathes in the dust, and in the latter case the heavy-metal poisoning is a much bigger concern than the radioactivity – it’s been in the ground for five billion years plus God only know how long before the Earth solidified, it’s obviously not decaying fast enough to throw off too terribly harmful an amount of radiation as long as you don’t inhale a LOT of it.