One of the key components for environmental risk assessment of engineered nanomaterials (ENMs) is data on bioaccumulation potential. Accurately measuring bioaccumulation can be critical for regulatory decision-making regarding material hazard and risk, and for understanding the mechanism of toxicity. This perspective provides expert guidance for performing ENM bioaccumulation measurements across a broad range of test organisms and species. To accomplish this aim, we critically evaluated ENM bioaccumulation within three categories of organisms: single-celled species, multicellular species excluding plants, and multicellular plants. For aqueous exposures of suspended single-celled and small multicellular species, it is critical to perform a robust procedure to separate suspended ENMs and small organisms to avoid overestimating bioaccumulation. For many multicellular organisms, it is essential to differentiate between the ENMs adsorbed to external surfaces or in the digestive tract and the amount absorbed across epithelial tissues. For multicellular plants, key considerations include how exposure route and the role of the rhizosphere may affect the quantitative measurement of uptake, and that the efficiency of washing procedures to remove loosely attached ENMs to the roots is not well understood. Within each organism category, case studies are provided to illustrate key methodological considerations for conducting robust bioaccumulation experiments for different species within each major group. The full scope of ENM bioaccumulation measurements and interpretations are discussed including conducting the organism exposure, separating organisms from the ENMs in the test media after exposure, analytical methods to quantify ENMs in the tissues or cells, and modeling the ENM bioaccumulation results. One key finding to improve bioaccumulation measurements was the critical need for further analytical method development to identify and quantify ENMs in complex matrices. Overall, the discussion, suggestions, and case studies described herein will help improve the robustness of ENM bioaccumulation studies.
|Number of pages
|Environmental Science: Nano
|Published - 2019
Bibliographical noteFunding Information:
This research was funded by the National Science Foundation (NSF) and the Environmental Protection Agency (EPA) under Cooperative Agreement DBI-0830117. Any opinions, findings, and conclusions expressed in this material are those of the author(s) and do not necessarily reflect those of either the NSF or EPA. This work has not been subjected to EPA review, and no official endorsement should be inferred. This work was also supported by NSF CBET 1437451, UKRI/NERC Research Grant NE/N006224/1, USDA grant 2016-67021-24985, USDA Hatch CONH00147, project NanoFASE through the European Union's Horizon 2020 research and innovation programme under grant agreement number 646002, and financial support to CESAM (UID/AMB/50017/2019), by FCT/ MCTES through national funds. This research was initiated at the 2016 U.S-EU: Bridging NanoEHS Research Efforts workshop in the Ecotoxicology Community of Research. We thank Rhema Bjorkland of the National Nanotechnology Coordination Office for assistance with this project.
© 2019 The Royal Society of Chemistry.
ASJC Scopus subject areas
- Materials Science (miscellaneous)
- Environmental Science (all)