The BEIR Committee studied the effects of long-term, low-level radiation exposure. With the exception of the acute effects suffered by the people of Rongelap in the weeks and months immediately following their exposure, the information and findings of the BEIR Committee are relevant to the conditions at Rongelap, Ailinginae, Rongerik, Utirik, Bikini and Enewetak. From the BEIR Report we learn that there are two principal concerns that one should have about radiation exposure at low levels. First, although the precise mechanisms are not understood, it is known that radiation increases the risk of cancer and of genetic abnormalities. 86. BEIR Report 46-48, Second, the relation between the amount of radiation to which one is exposed and the risk of ill-effects is such that even small amounts of radiation can cause harm. BEIR Report 51, 64, 89. Radiation does not create any new health problems. Both cancer and birth defects are known to occur in conditions where nothing more than background radiation is present. It is also observed that any number of nonradioactive substances ean play a part in causing both cancer and genetic defects. Radiation simply increases the risk of cancer and genetic defects, but because the underlying biological mechanisms are not fully understood, the precise role of any form of caccinogen or mutagen cannot be fully understood. We peer 4. OH} .