^(60)Co γ射线诱发人外周血淋巴细胞染色体畸变的剂量率效应

Dose-rate effect on chromosomal aberrations induced by ^(60)Co γ-rays irradiation in human peripheral blood lymphocyte

为准确估算受不同剂量率照射者的生物吸收剂量,分别采用低、中、高三种不同剂量率的60Coγ射线照射离体人血,一步法培养52h收获制片,根据染色体双着丝粒+环畸变率拟合剂量效应曲线。结果表明,相同吸收剂量点不同剂量率诱发的畸变率随剂量率的增加而增加,存在明显的剂量率效应,用低剂量率曲线估算的吸收剂量明显高于用高剂量率曲线估算的吸收剂量。因此,在估算吸收剂量时须考虑剂量率效应,应根据辐照的实际情况尽量选择剂量率相近的刻度曲线进行估算,结果才更为准确。

To estimate exactly the biological dose of persons exposed to different dose rate, human peripheral blood was exposed to ^60Coγ-rays in vitro at low, middle and high dose rates respectively and chromosome samples were prepared, then dose-response curves were established according to the dicentrics and ring frequencies. The result showed that the aberration frequency at same dose level increased with dose rate and there was an obvious dose-rate effect. Absorbed dose estimated with low dose-rate dose-response curve was higher markedly than that with high dose-rate dose-response curve. So, considering the effect of dose-rate, approximate dose-rate dose-response curve should be chosen when absorbed dose estimation and the result will be credible.