Children of Chernobyl cleanup workers do not show elevated rates of mutations in minisatellite alleles

The disaster at the Chernobyl Nuclear Power Plant in April 1986 was accompa nied by the release of large amounts of radioisotopes, resulting in the con tamination of extensive regions of the Ukraine, Byelorus and the Russian Fe deration. Cleanup workers (liquidators) and people living on land contamina ted with radioactive materials were most exposed. To assess the genetic eff ects of exposure to ionizing radiation after the Chernobyl accident, we hav e measured the frequency of inherited mutant alleles at seven hypermutable minisatellite loci in 183 children born to Chernobyl cleanup workers (liqui dators) and 163 children born to control families living in nonirradiated a reas of the Ukraine. There was no significant difference in the frequency o f inherited mutant alleles between the exposed and control groups. The expo sed group was then divided into two subgroups according to the time at whic h the children were conceived with respect to the fathers' work at the powe r plant. Eighty-eight children were conceived either while their fathers we re working at the facility or up to 2 months later (Subgroup 1). The other 95 children were conceived at least 4 months after their fathers had stoppe d working at the Chernobyl site (Subgroup 2). The frequencies of mutant all eles were higher for the majority of loci (i.e. 1.44 times higher for CEB1) in Subgroup 1 than in Subgroup 2. This result, if confirmed, would reconci le the apparently conflicting results obtained in the chronically exposed B yelorus population and the Hiroshima-Nagasaki A-bomb survivors. (C) 2001 by Radiation Research Society.