An estimation of biological effects of rare earth elements on health of workers in high technology field

为探讨稀土元素对人体健康的生物效应，研究了稀土元素在小鼠体内的分布、排泄及人体尿液中的排泄。1.稀土元素暴露良好指标的检测：成年雄性小鼠按1 mg/kg和10 mg/kg剂量分别静脉注射TbCl3a或YbCl3。测定脏器分布及尿、粪排泄的时程和剂量依赖性变化。血浆中给药元素浓度迅速下降。元素主要分布在肝脏和脾中。Th的排泄量小于Yb。1 mg/kg组和10 mg/kg组7天尿中Yb排泄量分别为给药量的30%和3%，结核为11%和0.5%。所有组的粪便排泄量均为剂量的10%至16%。提示尿中稀土含量是接触Trac…的良好指标。更多的稀土元素。2.稀土元素的富集法：高频等离子体质谱能灵敏地测定亚ppb级的稀土元素，但易受共存元素的影响。由于尿液中含有大量的碱和碱土元素，因此对去除共存元素和浓缩稀土元素的过程进行了研究。采用巴赫法和微柱法对两种螯合树脂(CHILEX 100和Muromac A-1)进行了测定。两种树脂均可用，采用Muromac A-1在线柱法。3.在尿样中的应用：本方法对尿样中稀土元素的回收率在80%以上。考察了缓冲液的元素污染情况和pH调节电极的元素逸出情况。4.人尿中稀土元素的测定：对照尿样中稀土含量小于或等于0.01 ppb。电池厂25名工人(镉镍电池和氢镍二次电池)尿液中铅浓度在检出限以下至1 ppb左右。父亲正在研究对照人群中稀土浓度的正常范围，以及工人尿液中稀土与其工作、工作时间的关系。较少

To investigate the biological effects of rare earth elements on human health, distribution and excretion of administered rare earths in mice and excretion of them in human urine were studied. 1. Examination of a good index of exposure to rare earth elements : Adult male mice were intravenously administered with TbCl_3 a or YbCl_3 3 independently at 1 and 10 mg element/kg. Time-course and dose-dependent change in organ distribution and excretion in urine and feces were determined. The concentrations of administered elements in plasma decreased rapidly. The elements were distributed mainly in liver and spleen. Excretion of Th were smaller than Yb. Excretion amounts of Yb within 7 days in urine corresponded to 30 and 3% of administered dose in 1 and 10 mg/kg groups, respectively, and those of Tb corresponded to 11 and 0.5%. Excretion in feces corresponded from 10 to 16% of dose in all groups. These results suggested that the rare earth contents in urine were good index of exposure to trac … More e amounts of rare earths. 2. Concentrating method of rare earth elements : High-frequency plasma-mass can perform sensitive determination of rare earth elements at sub-ppb levels, however, is easily affected by coexisting elements. Since urine contains high levels of alkaline and alkaline earth elements the process for removing coexisting elements and for concentrating rare earth elements were examined. Two kinds of cheleting resin (Chelex 100 and Muromac A-1) were tested with bach and mini-column methods. Both resins were available and on-line column method with Muromac A-1 was adopted. 3. Application to urine sample : Recovery rate of rare earths from urine samples were 80% or more by this method. The element contamination of buffer and element elusion from electrode used for pH adjust were observed. 4. Determination of rare earth elements in human urine : Urine sample from control contained 0.01 ppb or less rare earths. The concentrations in urine from 25 workers of battery factory (Ni-Cd battery and Ni-H_2 second battery) were in the range from under detection limit to about 1 ppb. Father studies about normal range of rare earths concentrations in control persons and the relation between rare earths in worker's urine and their job, working periods are in progress. Less