Your link was great! Full of interesting info.

In the article Parker touches on the other issue that escapes him.

If his pessimistic views on the damage from these ions was completely true we have a group of humans who have experienced much higher doses than the average surface dweller. He rightly points out most of the cosmic rays are block by our upper atmosphere.

So those outside of it have a much higher exposure. Were Astronauts and Cosmonauts do have slightly higher rate of cataract surgery they don't seem to be getting cancer at a higher rate. If Gene was right they should be getting it at a much higher rate than you or I.