Chromosomal aberrations of blood lymphocytes induced in vitro by radon-222daughter alpha-irradiation

Blood samples were irradiated in vitro with alpha-rays emitted from short-l ived radon decay products dissolved in the culture medium at doses between 0.03 and 41.4 mGy, The data were collected from experiments conducted durin g the period 1984-1992 and comprise a total of about 64000 scored metaphase s. For statistical reasons, only 60,022 metaphases were used for the subseq uent analysis. The results for total chromosome aberrations and dicentrics indicate a linear dose dependence in the dose range above about 10 mGy, con sistent with other experimental observations. At doses below about 10 mGy, aberration frequencies cannot be linearly extrapolated from higher doses, s uggesting that there is no dependence on dose within a certain low-dose ran ge. In addition, a statistically significant minimum has been observed at a dose of about 0.03 mGy, which is consistently lower than the related contr ol values. The behavior of the aberration frequencies in the low-dose regio n seems to be influenced by the control values, which also depend on the en vironmental radiation burdens to the donors before blood sampling and thus were significantly affected by the Chernobyl fallout. (C) 2000 Elsevier Sci ence B.V. All rights reserved.