CONCLUDING REMARKS

Although one cannot exclude the possibility of harm from occupational exposure to radiation at the doses likely to be received during a career of flying, it would be impossible to establish that an abnormality or disease in a particular individual resulted from such exposure.

In estimating radiation-induced health risks for air- crews and their progeny, we used dose-effect relationships recommended by national and international organizations recognized for their expertise in evaluating radiation ef- fects. However, considerable uncertainty exists in the es- timates because the original data is primarily from studies on individuals exposed to radiation at much higher doses and dose rates and generally of lower energy than the galactic cosmic radiation to which aircrews are exposed. Also, controls were often inadequate. These differences are the major reason that epidemiological studies involv- ing aircrews are important.