[Cytogenetic studies of human lymphocytes following blue light irradiation in vitro]

Human lymphocyte cultures were exposed for 0, 2, 4, 6, 8, 10, 12, and 14 h to the rays of the bluelight lamp NC-4400-04 developed by VEB Narva (Berlin) for the phototherapy of icterus neonatorum. The experiments revealed (1) a significant difference in the chromosomal aberration rate between bluelight treated and non-treated cultures and (2) a dependence of the aberration rate on the length of exposure. After the same duration of exposure the individual test series showed a great variation of aberration frequency. Chromatid gaps and breaks, chromosome gaps and breaks, chromatid translocations, and dicentric chromosomes were found to be induced. The majority of aberrations comprised gaps and breaks on the chromatid level.