How? The answer is "Nohavica's theory of alcoholic mountain". As you drink, you are climbing your alcoholic mountain. While you're climbing, everything is fine. You can even turn around and go back. But when you reach the summit and step over it, you are done. Nobody will help you. No doctors, no therapy, friends or medicine. Nobody. Then you die. Now you say "but my uncle was drinking whole life and he was fine". Sure, because his mountain was very tall. Nobody knows how tall is his mountain.

This Russian scientist had very tall radiation mountain. You try doing the same and you will die.