We don't need "new technology". To see the effects of (or lack of) Cosmic Radiation look at any of the epidemiological (sp?) studies done on Crew Members and cancer.
AFAIK the effects are so small as to be almost buried by our general ill health due to nights out of bed, irregular eating/sleeping habits, lack of exercise ( well, in my case), and the effects of our social activities down route
.....
Frankly IMHO it's down to personal cost vs. benefit - do you want to fly for a living or drive to work in the rush hour traffic everyday and perhaps increase your chances of dying in a Road Traffic Accident?