Bystander effects induced by serum from survivors of the Chernobyl accident

OBJECTIVE: To examine blood samples from survivors of the Chernobyl accident for evidence of persistent bystander factors or clastogenic factors and to look at the ability of melanin and melatonin, which are radioprotective agents capable of preventing bystander effects in cell culture to prevent toxic effects. MATERIALS AND METHODS: Serum was extracted from blood samples of control and test groups and added to human immortalized reporter cells, used in our laboratories for identification of bystander effects. These were then analyzed for evidence of micronucleus formation and viability. RESULTS: Micronuclei were significantly elevated in cells exposed to serum samples from Chernobyl liquidators and from workers in Gomel. Viability of cells treated with these sera was correspondingly reduced. CONCLUSION: Twenty years after the accident at the Chernobyl Plant, these is still evidence of the presence of clastogenic or bystander factors in the serum of populations exposed to radiation from the reactor.