Abstract
Study on dose and dose-rate-effect of chromosome aberrations in chronic low-dose-rate (LDR) exposure in human is very difficult, because they are usually exposed to from extremely low dose radiation and they are influenced by the effect of confounding factors, such as smoking. Therefore, we examined dose and dose-rate-effect of chromosome aberrations using mice chronologically irradiated by radiation different LDRs. In this study, C3H/HeN female mice were long-term exposed to 137Cs gamma-rays at 20 mGy/22h/day(910 uGy/h), 1 mGy/22h/day(45.5 uGy/h) and 0.05 mGy/22h/day(2.27 uGy/h) from the age of 8 weeks up to a maximum of about 700 days in SPF condition. In present analysis, we observed that both incidences of translocations and dicentric chromosomes in spleen lymphocytes detected by M-FISH were increased almost in linear up to a total accumulated dose of 8000 mGy, at a LDR of 20 mGy/22h/day. We observed dose and dose-rate-effect of both chromosome aberrations at a LDR of 1 mGy/22h/day. In addition, the chromosome aberration rates were compared between two LDRs (20 mGy/22h/day and 1 mGy/22h/day).This study was performed under contact with Aomori Prefecture Government, Japan.
