SAN FRANCISCO, July 24 -- In the aftermath of the Chernobyl nuclear accident in the former Soviet Union a decade ago, the leukemia rate among Greek infants has increased by as much as three-fold, researchers reported Wednesday. The study, published in the British journal Nature, noted no increase in other forms of leukemia from the radioactive fallout from the disaster, pointing to a high susceptibility to cancer during the early stages of embryonic life. 'The radioactive fallout from the Chernobyl accident has increased the incidence of infant leukemia in Greece by as much as two to three times,' said lead study author Dimitrios Trichopoulos, chairman and professor of epidemiology at the Harvard School of Public Health in Cambridge, Mass. 'The apparently carcinogenic effect is probably due to exposure during the early stages of intrauterine life. No increase in other forms of leukemia was noted in this study.' Outside of the former Soviet Union, Greece had among the highest levels of contamination following the fire and explosion at the Chernobyl Nuclear Power Plant in the Ukraine April 26, 1986. All of the diagnosed cases of childhood leukemia in Greece have been recorded since 1980. The nuclear accident more than doubled the risk of leukemia in children born to mothers exposed to fallout during their pregnancy, Trichopoulos said. Interestingly, exposure of parents to radiation before conception apparently posed no later risk of the cancer, the researchers found. 'The findings suggest the susceptibility to carcinogenesis is very high during the early stages of embryonic life,' Trichopoulos said.
'In this study this phenomenon was documented for infant leukemia, characterized by a specific chromosomal abnormality -- but the observations may have wider implications.' A second significant finding was that the exposure of the parents' testes or ovaries to low levels of ionizing radiation before conception apparently has no effect on infants or childhood leukemia -- despite some recent claims to the contrary, the study authors said. 'The consequences of the accident in Chernobyl have yet to be fully realized,' Trichopoulos said. 'We feel the incidence of infant leukemia may be a direct reflection of embryonic irradiation.'