尿氟的基准剂量及其与改水后儿童碱性磷酸酶相关性研究

目的]通过对汕头市地氟病区改水后儿童尿氟含量(UF)及血清碱性磷酸酶(AKP)活性的测定,探索尿氟的接触限值及其与AKP活性的相关性。方法]采用氟离子电极法测定汕头市4个病区村,1个对照村饮水氟含量及8～12岁小学生尿氟含量并测定血清中AKP活性,用基准剂量法(BMD法)计算氟接触基准剂量。结果]汕头市地氟病区4病区村及1个对照村饮用水水氟测定结果均低于0.2mg/L,除改水14年村外,不同改水年限的各村儿童尿氟含量与对照村相比差异有统计学意义(χ2=132.411,td分别为16.814、17.403、19.550,P均﹤0.05),改水15、17年村AKP活性与对照村相比显著降低(F=9.885,td分别为1.348、1.514,P均﹤0.05)。在尿氟﹤2.0mg/L水平,AKP活性异常率随着尿氟含量升高而上升,呈显著剂量—反应关系。基准剂量(BMD)法计算得尿氟基准剂量值及基准剂量下限(BMDL)值分别为2.77mg/L,1.19mg/L。结论]AKP活性随改水时间延长呈下降趋势;氟病区8～12岁儿童尿氟致AKP改变的生物接触限值为﹤1.0mg/L。

THE BMD OF URINE FLUORIDE OF CHILDREN AND THE STUDY OF THE RELATIONSHIP BETWEEN IT AND ACTIVITIES OF AKP

Objective]To chase the exposure limit of UF and the relationship between UF and activity of AKP in serum through the determination of urine fluoride(UF)and activity of AKP in serum of children in the endemic flourosis area after water improvement in Shantou.Methods]We adopted the introduction of ion selective electrode method to determine the fluoride of 4 endemic fluorosis villages and 1 control village in Shantou.We randomly selected students of 8-12 years old,and determined their urine fluoride and AKP in serum,calculated the value of exposure of flourosis by using Benchmark Dose(BMD)method.Results]The fluoride in drinking water of 4 endemic fluorosis villages and 1 control village were all lower than 0.2mg/L.Except the village of 14 years water improvement application,there was significant difference in the UF concentration among different period of water improvement,difference also found when comparing with the control village(P﹤0.05).Comparing with control village,the activity of AKP of villages of 15 and 17 years water improvement applied were lower obviously(P﹤0.05).Under the level of UF﹤2.0mg/L,the activity of AKP shows obviously dose-response relationship with UF.Values of BMD and BMDL of urine fluoride were 2.77mg/L,and the 1.19 mg/L were calculated by BMD method.Conclusion]With the time of water improvement increase,the activity of AKP become lower.The biological limit value of UF in the 8-12 years old children in endemic fluorosis was suggested as ﹤1.0 mg/L.