ABSTRACT

Animal bioassays have been developed to estimate oral relative bioavailability (RBA) of metals in soil, dust, or food for accurate health risk assessment. However, the comparability in RBA estimates from different labs remains largely unclear. Using 12 soil and soil-like standard reference materials (SRMs), this study investigated variability in lead (Pb) and arsenic (As) RBA estimates employing a mouse bioassay in 3 labs at Nanjing University, University of Jinan, and Shandong Normal University. Two performances of the bioassay at Nanjing University in 2019 and 2020 showed reproducible Pb and As RBA estimates, but increasing the number of mouse replicates in 2020 produced more precise RBA measurements. Although there were inter-lab variations in diet consumption rate and metal accumulation in mouse liver and kidneys following SRM ingestion due to differences in diet composition, bioassays at 3 labs in 2019 yielded overall similar Pb and As RBA estimates for the 12 SRMs with strong linear correlations between each 2 of the 3 labs for Pb (R² = 0.95–0.98 and slope = 0.85–1.02) and As RBA outcomes (R² = 0.46–0.86 and slope = 0.56–0.79). The consistency in RBA estimates was attributed to the relative nature of the final bioavailability outcome, which might overcome the inter-lab variation in diet consumption and metal uptake in mice. These results increased the confidence of use of mouse bioassays in bioavailability studies.

摘要

已经开发出动物生物测定法来估计土壤、灰尘或食物中金属的口服相对生物利用度 (RBA)，以进行准确的健康风险评估。然而，来自不同实验室的 RBA 估计值的可比性在很大程度上仍不清楚。本研究使用 12 种土壤和类似土壤的标准参考物质 (SRM)，在南京大学、济南大学和山东师范大学的 3 个实验室中采用小鼠生物测定法调查了铅 (Pb) 和砷 (As) RBA 估计值的变异性。南京大学 2019 年和 2020 年的两次生物测定性能显示出可重现的 Pb 和 As RBA 估计值，但在 2020 年增加小鼠重复次数会产生更精确的 RBA 测量值。²  = 0.95–0.98 且斜率 = 0.85–1.02）和作为 RBA 结果（R ²  = 0.46–0.86 且斜率 = 0.56–0.79）。RBA 估计的一致性归因于最终生物利用度结果的相对性质，这可能会克服小鼠饮食消耗和金属吸收的实验室间差异。这些结果增加了在生物利用度研究中使用小鼠生物测定的信心。