Yes, there have been studies done on cosmic radiation, but they were quickly stifled. The cancer rate is higher among people who fly alot. I had the exact numbers, but can't find them now. There is also a much higher incidence of miscarriage. Did you know that pilots and flight attendants are condisered to be "radiation workers" and must be made aware of the risks by their employers? Food for thought...although it hasn't grounded me yet.