An interlaboratory evaluation of the variability in arsenic and lead relative bioavailability when assessed using a mouse bioassay

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.

KEYWORDS:

• Contaminated soil
• indoor dust
• metal oral bioavailability
• standard reference materials
• mouse liver and kidneys

Acknowledgments

This work was supported by the National KeyResearch and Development Program of China (2018YFC1801004), the National Natural Science Foundation of China (42022058, 41877356, 21637002, 41673101, 41907118, and 41807485), Fundamental Research Funds for the Central Universities (0211/14380155), and Shandong Provincial Natural Science Foundation (ZR2019BD0002).

Data availability statement

The data that support the findings of this study are available from the corresponding author upon request ([email protected]).

Disclosure statement

The authors declare that there are no conflicts of interest

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This work was supported by the National Key Research and Development Program of China (2018YFC1801004), the National Natural Science Foundation of China [21637002, 41673101,41807485,41907118,42022058, 41877356]; Natural Science Foundation of Shandong Province [ZR2019BD002]; Fundamental Research Funds for the Central Universities [0211/14380155].