Engineered nanomaterials (ENMs) have a significant commercial potential for ENM-enable products as a result of novel or enhanced properties. However, the unique behaviors of ENMs may also cause artifacts, spurious results, effects, or findings, when evaluating their potential ecotoxicological risks. While individual studies have identified artifacts, they have not yet been systemically reviewed and detailed test recommendations to minimize potential artifacts in ecotoxicological assays are not yet available. In this manuscript, we discuss artifacts that can occur at each step of an ecotoxicity test: procurement or synthesis of the ENMs and assessment of potential toxic impurities such as metals or endotoxins, ENM storage, dispersion of the ENMs in the test medium, conducting the ecotoxicological assay including direct interference with assay reagents and indirect effects such as nutrient depletion, and assessment of the ENM biodistribution in the organism. Recommendations for avoiding artifacts include thorough characterization of the initial ENMs including measuring endotoxin concentrations, taking steps to minimize changes to the ENMs during storage, running a carefully chosen set of experimental controls (e.g., to assess impacts of nutrient depletion, ENM specific effects, impurities in ENM formulation, desorbed surface coatings, the dispersion process, and direct interference of ENM with toxicity assays), and testing orthogonal methods when available to assess ENMs in organisms.
Citation: Environmental Science and Technology
Pub Type: Journals