Radiosensitivity Parameters for Cell Survival in \u3ci\u3eTradescantia\u3c/i\u3e and for Chromosome Aberrations in Chinese Hamster Cells

Data for the loss of reproductive integrity of Tradescantia stamen hairs irradiated with 250 keV X rays and 0.43 and 5.6 MeV neutrons are fitted with radiosensitivity parameters from track theory, with E0 and m from X-ray data while σ0 and κ are then found from neutron irradiations. The X-ray data display a clear shoulder with 100% survival below 0.18 Gy and a “linear tail.” Data for abnormal metaphases and chromatid exchanges in Chinese Hamster cells have also been fitted with parameters. Parameters for abnormal metaphases are nearly identical with those obtained years ago for cell killing from data in the same paper, strongly supporting the view that cell killing arises from chromosome aberrations. These dose-response curves are also shouldered with a “linear tail.