Multimedia Methods Branch, Watershed and Ecosystem Characterization Division, Center for Environmental Measurement & Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, United States.
South Australian Health and Medical Research Institute, Adelaide 5000, Australia.
J Agric Food Chem. 2020 Mar 4;68(9):2615-2622. doi: 10.1021/acs.jafc.9b06537. Epub 2020 Feb 19.
Hand-to-mouth activity in children can be an important route for ingestion of soil and dust contaminated with inorganic arsenic. Estimating the relative bioavailability of arsenic present in these media is a critical element in assessing the risks associated with aggregate exposure to this toxic metalloid during their early life. Here, we evaluated the performance of a mouse assay for arsenic bioavailability in two laboratories using a suite of 10 soils. This approach allowed us to examine both intralaboratory and interlaboratory variations in assay performance. Use of a single vendor for preparation of all amended test diets and of a single laboratory for arsenic analysis of samples generated in the participating laboratories minimized contributions of these potential sources of variability in assay performance. Intralaboratory assay data showed that food and water intake and cumulative urine and feces production remained stable over several years. The stability of these measurements accounted for the reproducibility of estimates of arsenic bioavailability obtained from repeated intralaboratory assays using sodium arsenate or soils as the test material. Interlaboratory comparisons found that estimates of variables used to evaluate assay performance (recovery and urinary excretion factor) were similar in the two laboratories. For all soils, estimates of arsenic relative bioavailability obtained in the two laboratories were highly correlated ( = 0.94 and slope = 0.9) in a linear regression model. Overall, these findings show that this mouse assay for arsenic bioavailability provides reproducible estimates using a variety of test soils. This robust model may be adaptable for use in other laboratory settings.
儿童的手口活动可能是摄入受无机砷污染的土壤和灰尘的重要途径。评估这些介质中存在的砷的相对生物利用度是评估在其早期生活中与接触这种有毒类金属的总暴露相关的风险的关键因素。在这里，我们使用 10 种土壤评估了两个实验室中用于砷生物利用度的小鼠测定法的性能。这种方法使我们能够检查实验室内部和实验室之间测定性能的变化。使用单一供应商制备所有添加的测试饮食，以及单一实验室分析参与实验室中生成的样品，可最大程度地减少这些潜在的变异性来源对测定性能的影响。实验室内部测定数据表明，食物和水的摄入量以及尿液和粪便的累积量在几年内保持稳定。这些测量值的稳定性解释了使用亚砷酸钠或土壤作为测试材料进行重复实验室内部测定时获得的砷生物利用度估计值的重现性。实验室间比较发现，用于评估测定性能的变量（回收率和尿排泄因子）的估计值在两个实验室中相似。对于所有土壤，在两个实验室中获得的砷相对生物利用度的估计值在线性回归模型中高度相关（= 0.94 和斜率 = 0.9）。总体而言，这些发现表明，这种用于砷生物利用度的小鼠测定法使用各种测试土壤提供了可重复的估计值。这种强大的模型可能适用于其他实验室环境。
