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Considerations of Environmentally-Relevant Test Conditions for Improved Evaluation of Ecological Hazards of Engineered Nanomaterials



Patricia Holden, Jorge Gardea-Torresdey, Frederick Klaessig, Ronald Turco, Monika Mortimer, Kerstin Hund-Rinke, David Avery, Damia Barcelo, Renata Behra, Yoram Cohen, Laurence Deydier-Stephan, Barbara Harthorn, Danail Hristozov, John Johnston, Agnes Kane, Larry Kaputska, Arturo Keller, Hunter Lenihan, Wess Lovell, Catherine Murphy, Roger Nisbet, Elijah J. Petersen, Martin Scheringer, Monita Sharma, David Speed, Yasir Sultan, Jason White, Eva Wong, Baoshan Xing, Meghan Steele Horan, Hilary Godwin, Andre Nel


Engineered nanomaterials (ENMs) entering the environment could impact biological populations or entire ecosystems. Ecotoxicology aims to determine effective concentrations, which often exceed those in the environment. ENM behaviors in complex media impede measuring or predicting real-world concentrations. Various research communities view differently whether ecological testing should be under environmentally relevant conditions—where observing sub-chronic outcomes is difficult—versus higher ENM doses, where response mechanisms are observable. What exposure conditions are typically used in assessing ENM hazards to populations? What conditions are used to test ecosystem-scale hazards? What is known regarding actual ENMs in the environment, via measurements or modeling simulations? How should exposure conditions, ENM transformation, dose, and body burden be used in interpreting biological and computational findings for assessing risks? Multiple experts deliberated these questions in a University of California Center for Environmental Implications of Nanotechnology (UC CEIN)-sponsored workshop on March 19-20, 2015. Herein, we report the results. Although not by consensus, a general recommendation was that researchers improve nano-ecotoxicology by choosing test endpoints, duration, and study conditions—including ENM test concentrations—that align with realistic exposure scenarios. Another recommendation was that testing should proceed via tiers, for example through lower to higher levels of biological complexity. Finally, environmental realism in ENM hazard assessments should involve greater coordination among ENM quantitative analysts, exposure modelers, and ecotoxicologists, across government, industry, and academia.
Environmental Science and Technology
Created June 8, 2016, Updated February 19, 2017