The Relative Biological Effectiveness of Neutrons, X-Rays, and Gamma Rays for the Production of Lens Opacities: Observations on Mice, Rats, Guinea-Pigs, and Rabbits

Abstract

For the production of cataracts in mice, rats and guinea pigs, cyclotron neutrons of 1 to 2 MEV mean effective energy, administered at high intensity, were 2 to 4 times as effective as 250 kvp X rays and 3 to 4 times as effective as 1.2 MEV gamma rays; fission neutrons from an experimental nuclear detonation had a similar cataractogenic effectiveness in mice. There exists a species-specific sensitivity of the lens in the order of decreasing sensitivity: mouse, rat, guinea pig, rabbit. The cataractogenic effect of neutrons and gamma rays decreased only slightly if irradiation was fractionated.