Heavy Ion Irradiation of HeLa Cells

Abstract
HeLa cells were irradiated with 250-kvp X-rays, 40-Mev [alpha]-particles (+2), 69-Mev lithium ions (+3), 105-Mev carbon ions (+6), and 130-Mev oxygen ions (+8). The X-rays, a-particles, and lithium ions give multitarget- type survival curves showing thresholds at low dose. The carbon and oxygen ion irradiations give exponential (single-hit) curves with no thresholds.