Perinatal mortality, congenital malformations, spontaneous abortions
In Austria, one of the
countries with the highest average fallout levels outside the former Soviet
Union, perinatal mortality decreased in 1987 relative to the long-term trend.
The analysis of monthly perinatal mortality data yields an inverse dose
dependency at lower doses, followed by an increase at higher doses.
Perinatal mortality in Gomel,
the most contaminated region of Belarus, is compared with the rest of Belarus.
Perinatal mortality rates do not differ significantly until 1988 but then the
rate in Gomel increases relative to the rates in the rest of Belarus and stays
about 30% higher until 1998. This increase can be explained as a late effect of
strontium uptake. Data from the Ukrainian regions Zhytomyr and Kiev,
with the highest levels of fallout in Ukraine, yield similar results.
Data of congenital
malformations were only available for Bavaria, the German federal state with the
highest fallout level. An association of malformation rates with caesium soil
contamination is found at the end of 1987, seven months after a peak of caesium
burden of pregnant women in April and May 1987.
In February 1987, a
significant 11.4% drop of birth rate is observed in Bavaria which might be
explained by an increased rate of spontaneous abortions 9 months earlier, in May
1986. In the most contaminated Ukrainian regions Zhytomyr and Kiev, the birth
rate dropped by 25% in February 1987.
The health effects reported
here all show a temporal correlation with the radiation exposure from Chernobyl.
According to conventional radiobiological knowledge, no teratogenic effects are
expected to occur below a threshold dose of about 100 mSv. Even in the most
contaminated regions of Germany, however, the extra doses to the foetus were
below 1 mSv in the first follow-up year. Therefore the results contradict the
widely accepted concept of a threshold dose for radiation damage during foetal