There is an even better and long term study that has been going on since WWII. There were Australians in a POW camp 1.7 miles from Ground Zero during the Nagasaki blast. They are monitored like no other people on the planet. They suffer the same leukemia and cancer rates as the general population. The reality of radiation sickness is this, if you get hit by a massive dose of gamma radiation. You are toast. If you get a moderate dosage, and you are susceptible, you are going to die a miserable death.
On the other hand, if you are not one of those who die within a month, you will live a relatively normal life. Your offspring may, or may not suffer from genetic mutations. Their offspring probably won't. The fallout will concentrate in the low lying areas, but for the most part, so long as you don't eat it you won't get sick.
I have a PhD in geology, so this is not stuff pulled from the ether. This is legit peer reviewed science I am reciting. Obviously, there a re a shitload of caveats based on very specific, localized conditions, but generally speaking, this is the outlook. And yes, it is grim.
Great, they did a study of people only exposed to the immediate effects of an explosion, then were taken home.
They were not forced to live under that type of conditions for years afterwards. And I am sure if you compared them to those that had to live in the immediate aftermath of Hiroshima or Nagasaki they are doing better as you say.
Fallout is an accumulative disorder, where the longer you live in it, the more problems you will have. Gamma Rays, super. All those do is turn you into the Incredible Hulk.
Now all joking aside, we know that most people do die of the immediate effects. Heat, Blast, Radiation. But that is only most people who are within the range of those effects. Long term, the fallout is the big killer, spreading out over tens of thousands of square miles. And even worse it accumulates over time in the body. Herbivores suffer the least, they eat plants which get at most moderate doses. For Carnivores and high level omnivores (us), we get even higher levels because we consume the herbivores that have accumulated what they have eaten. And many particles once introduced into the body like joining things like bones, so they continue to poison the body.
You are a geologist, great. So tell me, what killed the most when the Yellowstone Caldera (then still the Bruneau-Jarbridge) blew up? Sure, most of the life in and around that area of Idaho-Oregon-Nevada died almost instantly, but the ash clouds were killing enough animals in Nebraska half a continent away that there is now a state park because of those fossils. In reality, almost half the life on the entire continent died, mostly from the ash and not the eruption itself. This is no different.
Geologically, replace the ashfall from a supervolcano with fallout and maybe you will understand what I am saying.
Fallout is no different. That is the real long-term killer in any nuclear exchange. Millions will die in the blast, tens of millions will die over the next 20-50 years downwind who were not even affected by the initial event. And no, the fallout will not "concentrate in the low lying areas". That is direct effect. It will effect our water, our food supply, the animals we eat. Just like how tuna which almost never travel to inland waters are effected by mercury. They eat the fish that migrate from fresh to salt water, and they get the mercury in inland freshwater areas where mining happens. The migrating salmon and trout pick it up, the tuna then eat it and get the mercury.
Come on, you claim to have a PhD in Geology! Yes, as me you tend to think of thousands of years of time as hardly worth looking at. But you must understand the accumulative effects of radioactive fallout flowing up and down the food chain.