低剂量γ照射、散裂中子照射及噪声对大鼠的复合效应

COMBINED EFFECT OF LOW DOSE γ-RAY,SPALLING NEUTRON, AND NOISE ON RATS

目的研究60Coγ射线、252Cf散裂中子及噪声复合作用于大鼠的生物效应,为阐明复合环境因素对特殊作业人群健康的影响及制定干预措施提供理论依据。方法将SD大鼠按体质量随机分为实验组、对照组,每组8只。实验组每天暴露于60Coγ射线(剂量率为0.072 Gy/h,累积剂量为0.5 Gy)、252Cf散裂中子(剂量率为0.085 mGy/h,累积剂量为12 mGy)和噪声〔(90±5)dBA〕复合环境因素中,连续7 d,对照组置于正常环境中。第8天检测2组大鼠外周血象、主要脏器指数、骨髓DNA含量、血清SOD活性和MDA含量。结果实验组的血小板为728 G/L,明显低于对照组(838 G/L),P<0.05;实验组脾指数和胸腺指数分别为0.002和0.001 7 mg/g,低于对照组(0.003和0.002 2 mg/g),P<0.05;实验组骨髓DNA含量(吸光度值)为0.886 2,明显低于对照组(1.303 9),P<0.01。结论低剂量γ射线、散裂中子及噪声复合作用对大鼠造血系统和免疫系统造成严重损伤。

Objective To investigate the combined biological effect of γ-ray of 60Co, spalling neutron of 252 Cf, and noise on rats, so as to provide theoretical basis for explaining the effect of combined environmental factors on the health of special operation population and for working out intervention measures. Methods Sixteen SD rats were randomly divided into experimental group and normal control group. The animals in experimental group were exposed to 6Co γ-ray （0.5 Gy）, noise[ （90_＋5） dBA], and spalling neutron of 252Cf （ 12 mGy）. Peripheral blood, organ index, marrow DNA content, SOD activity, and MDA content were detected. Results： The level of platelet, spleen index, and thymus index in experimental group [ （ 728 × 10^9 ）/L, 0. 002, and 0.0017 respectively ] were significantly lower than those in control group [ （ 838 × 10^9 ）/L,0. 003, and 0.0022 respectively ], （ P〈0.05 ）. The marrow DNA content in experimental group （A260：0. 8862 ） was also significantly lower than that in control group （ A260 ： 1. 3039 ）, （ P〈0.01 ）. Conclusion The hematopoietic system and immune system of rats were markedly damaged by the combined effect of low dose γ-ray, spalling neutron, and noise.