Twinning in the offspring of parents with chronic radiation exposure from nuclear testing in Kazakhstan.

The population of the Semipalatinsk region of Kazakhstan was chronically exposed to radioactive fallout from above-ground nuclear tests conducted during 1949-1956 by the Soviet Union. We investigated the effect of radiation exposure and other factors on risks of twinning overall and of same- and different-sex twinning and hence estimated dizygotic and monozygotic twinning rates in 11,605 deliveries around Semipalatinsk, 141 of which were twin, to 3992 mothers exposed to fallout during 1949-1956. Overall, the same-sex twinning rate was 7.

Sex ratio in the offspring of parents with chronic radiation exposure from nuclear testing in Kazakhstan.

The former Soviet Union conducted a nuclear test program in the Semipalatinsk region of northeastern Kazakhstan in 1949-1989. The population in the vicinity of the test site was chronically exposed to radiation fallout, especially from above-ground tests during 1949-1956. Male:female sex ratio has been proposed as a measure of reproductive health, with some reports suggesting an alteration in the sex ratio of offspring of parents exposed to radiation.

Radiation exposure due to local fallout from Soviet atmospheric nuclear weapons testing in Kazakhstan: solid cancer mortality in the Semipalatinsk historical cohort, 1960-1999.

Little information is available on the health effects of exposures to fallout from Soviet nuclear weapons testing and on the combined external and internal environmental exposures that have resulted from these tests. This paper reports the first analysis of the Semipalatinsk historical cohort exposed in the vicinity of the Semipalatinsk nuclear test site, Kazakhstan. The cohort study, which includes 19,545 inhabitants of exposed and comparison villages of the Semipalatinsk region, was set up in the 1960s and comprises 582,750 person-years of follow-up between 1960 and 1999.