Interesting how our understanding of risks change. I have that Soviet illustrated pop science book about space travel. Published in 1955 - two years before Sputnik - the main concern it had was the harm of microgravity. Huge unknown at the time, there were fears that humans would not able to function properly in weightlessness, so all the designs of orbital stations were with centrifugal gravity.

DNA at that point was barely discovered and genetics remained a pariah science under CPSU for years.

(The book also refers to space pilots as astronauts, not cosmonauts, and describes polar caps and channels on Mars. Wild.)