染色体型畸变率指标在射线工作者健康监护中应用的探讨

Study on the application of chromosome aberration frequency for health inspection in X-ray workers

目的探讨染色体型畸变率增加在射线工作者健康监护中应用的意义。方法采用微量全血培养法,按WHO建议的标准对射线工作者(医用诊断X射线组、工业探伤组和海关货检组共772名及9名超剂量组)和40名正常人组进行染色体型畸变分析;职业外照射剂量用热释光剂量计测得。结果①各射线组的体型畸变率均比正常人增加了1～2倍,但两类人员的畸变类型均以无着丝粒畸变为主,占体型畸变率约95%,“双+环”等畸变极少;②体型畸变率的分布:95%的正常人畸变率<1%、其余为1%,各射线组的畸变率均分布在0%至≥3%的4个区段,其中2%和≥3%的2个区段合计为8.2%;③年剂量与体型畸变率分布:体型畸变率为2%和≥3%的2个区段中,年剂量当量<1mSv组仅占11.6%、3～19mSv组占66.6%、而>50mSv组(超剂量组)为100%;④各工龄组间体型畸变率的分布变化不大。结论在健康监护工作中,选择体型畸变率≥2%作为“预警值”较为合适;“双+环”或“稳定性畸变”的增加有较大的诊断价值;“预警值”应结合分析细胞量和其他指标综合判断才能得出客观的结论。

Objective To study the sense of increasing frequency of chromosome aberration for health inspection in X-ray workers. Methods Based on the suggested standard by World Health Organization (WHO), with the method of micro amount of full blood sample cultivation, the analysis was taken to 772 exposed workers from the medical diagnostic X-ray subgroup, flaw detecting subgroup and customs inspecting subgroup, and to 9 workers from the overdose group, as well as to 40 from the control group. The occupational radiation doses were detected by TLD dose meter. Results ① 95% of the types of chromosome aberration in all X-ray groups and normal controls were observed as acentric aberration. However, the chromosome somatotype aberration in X-ray groups was all 1 to 2 times higher than that in controls. ② The distribution of chromosome somatotype aberration: the aberration frequency in 95% of the controls was less than 1% and the rest 5% controls was equal to 1%; the aberration frequency in the exposed group ranged from 0% to ≥3%, about 8.2% of the workers ranged from 2% to ≥3%. ③ The distribution of the annual radiation doses versus chromosome somatotype aberration: within the two sections of 2% and ≥3%, the group of annual dose <1 mSv was 11.6%, group 3～19 mSv was 66.6%, and group over 50 mSv was 100%. ④ The changes of chromosome somatotype aberration frequency were not obviously related to the length of service. Conclusion It is suggested that the appropriate precaution value of chromosome somatotype aberration frequency should be equal to or over 2%. There is significant diagnostic value when the frequency of “dicentric+ring” or “stable aberration” is increased. It is also pointed out that a correct conclusion can only be elicited when the precaution value is used together with the numbers analysed and other indexes.