Portal de Periódicos da CAPES

Dose-effect Relationship of Dicentric and Ring Chromosomes in Lymphocytes of Individuals Living in the High Background Radiation Areas in China

2000; Oxford University Press; Volume: 41; Issue: SUPPL Linguagem: Inglês

10.1269/jrr.41.s63

1349-9157

Tao Jiang, Isamu Hayata, Chunyan Wang, Sayaka Nakai, Yao Suyan, YONGLING YUAN, LIANLIAN DAI, Qing-Jie Liu, Deqing Chen, LUXIN WEI, Tsutomu Sugahara,

Effects of Radiation Exposure

Chromosomes of 39 healthy family members (3 generations from 13 families) living both in the high-level background radiation areas (HBRA) and the control areas (CA) were studied. Cumulative dose from birth to the time of blood sampling was estimated by calculating measured exposure rate in each individual. The cumulative doses ranged 30.9–358.9 and 6.0–59.2 mGy for HBRA and CA, respectively. Peripheral lymphocyte chromosome preparations were made according to our improved method. Dicentric and ring chromosomes (Dic+Rc) were scored in average 2,527 cells per individual in HBRA and 2,694 cells in CA under a microscope equipped with an automated stage. A positive correlation between Dic+Rc and age was found in HBRA, while no such dose relationship was clear in CA. The frequency of Dic+Rc linearly increases over lifetime due to chronic low dose exposure and it is likely that the activation of repair enzymes is not triggered in the present HBRA. Threshold dose (rate) of the induction of chromosome aberrations, if any, is below the present dose (rate) level.