CHANGES IN REGISTERED CONGENITAL-ANOMALIES IN THE REPUBLIC-OF-BYELARUS AFTER THE CHERNOBYL ACCIDENT

A descriptive analysis of birth defects and malformations was performe d to assess whether the rates of these defects correlate with the geog raphic areas of Belarus that received different levels of Cs-137 conta mination resulting from the Chernobyl catastrophe. Since this accident in 1986, the frequency of both congenital and fetal abnormalities in the Republic of Belarus has apparently increased. This increase is mos t prominent in areas with at least 555 9Bq/m(2) radioactive contaminat ion, although it has not been possible to correlate the individual dos e received by a pregnant woman with the incidence of congenital malfor mations. The types of anomalies that were most increased in frequency were multiple congenital malformations, polydactyly, and reduction lim b defects. These malformations are commonly associated with dominant n e cv mutations. Chromosomal disorders such as occur in Down syndrome w ere not increased in frequency, nor could teratogenic effects be attri buted to exposure to ionizing radiation. Preventive measures have appa rently reduced the number of births with congenital abnormalities but have had no apparent effect on the frequency of fetal defects. Results of our analysis are consistent with the hypothesis that ionizing radi ation released during the Chernobyl accident may have placed fetuses a nd neonates at risk for congenital malformations. Epidemiological stud ies are now required to determine whether a mother's radiation dose co rrelates with congenital malformations in her children.