INDUCTION OF SISTER‐CHROMATID EXCHANGES IN ICR 2A FROG CELLS EXPOSED TO 254 NM AND SOLAR UV WAVELENGTHS

Abstract— Exposure of ICR 2A frog cells to 254 nm UV induced the formation of sister‐chromatid exchanges (SCEs) in a fluence‐dependent manner. Cells were also exposed to the UV produced by a fluorescent sunlamp that was filtered through 8C Mylar in order to simulate the mid‐UV(290–320 nm) portion of sunlight reaching the earth's surface. In this instance, SCEs were induced in a linear fashion at low fluences but reached a plateau at a low level of induced SCEs. In addition, pretreatment of cells with the solar UV followed by exposure to 254 nm UV resulted in a significantly lower level of SCEs than in cells exposed to 254 nm UV alone.