More than 130 environmental, health, and anti-nuclear activists this week protested the composition of a new panel of scientists that will try to determine the cancer risks from low doses of radiation. In a letter to the National Academy of Scientists, under which the high-profile panel has been formed, the activists charged that the 20-member panel is dominated by scientists beholden to nuclear interests. They said the panel includes a significant number of scientists who have claimed that current assumptions about low-dose radiation overstate the health risks and a few scientists who have asserted that radiation is not harmful below a certain dose, while scientists whose studies have found elevated cancer levels from low-dose radiation exposure were excluded. The panel, which holds its first meeting today, will conduct a three-year study, which is expected to be very influential in setting radiation standards in the U.S.