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Modern nano-engineered pesticides have great promise for agriculture due to their extended, low dose release profiles that are intended to increase effectiveness but reduce environmental harm. Whether nanopesticides, including copper (Cu) formulations, cause reduced levels of toxicity to non-target aquatic organisms is unclear but important to assess. Predicting how aquatic species respond to incidental exposure to Cu-based nanopesticides is challenging because of the expected very low concentrations in the environment, and the two forms of exposure that may occur, namely to Cu ions and Cu nanoparticles. We conducted Cu speciation, tissue uptake, and 7-day toxicity laboratory experiments to test how a model estuarine organism, the amphipod Leptocheirus plumulosus, responded to two popular Cu-based nanopesticides, CuPRO and Kocide, and conventional CuCl 2 . Exposure concentrations ranged from 0 to 2.5 ppm, which were similar to those found in estuarine water located downstream of agricultural fields. Cu dissolution rates were much slower for the nanopesticides than the ionic formula, and Cu body burden in amphipods increased approximately linearly with the nominal exposure concentration. Amphipod survival declined in a normal dose-response manner with no difference among Cu formulations. Growth and movement rates after 7 days revealed no difference among exposure levels when analyzed with conventional statistical methods. By contrast, analysis of respiration rates, inferred from biomass measurements, with a bioenergetic toxicodynamic model indicated potential for population-level effects of exposure to very low-levels of the two nanopesticides, as well as the control contaminant CuCl 2 . Our results indicate that toxicity assessment of environmental trace pollutant concentrations may go undetected with traditional ecotoxicological tests. We present a process integrating toxicity test results and toxicodynamic modeling that can improve our capacity to detect and predict environmental impacts of very low levels of nanomaterials released into the environment. the maintenance of biodiversity (Lenihan et al., 2001;Needles et al., 2015). Estuaries also sequester and harbor microorganisms that degrade anthropogenic contaminants (Boorman, 1999;Kehrig et al., 2003). Thus, the fate, transport, and ecological impacts of emerging pollutants, including nanomaterials, are key concerns in estuarine ecosystem science and management (Klaine et al., 2008;Holden et al., 2013Holden et al., , 2016. To date, many concepts about the ecological implications and impacts of nanomaterials and other emerging contaminants come from traditional ecotoxicological risk assessments that are frequently hampered unavoidably by narrow subsets of relevant species, toxicants, exposure conditions, and levels of impact (Jager et al., 2011;Muller et al., 2015).Estuaries are major recipients of pesticide-laden runoff from

A B S T R A C TIn the environment, anthracene is characterized as being persistent, bioaccumulative and toxic to aquatic organisms. Biotransformation of xenobiotic substances, such as anthracene, produces reactive oxygen species that may induce DNA strand breaks. The aim of the present study was to evaluate the DNA damage in juvenile T. carolinus exposed to different concentrations (8, 16 and 32 µg.L -1 ) of anthracene for 24 h in the dark then subsequently allowed to depurate in clean water for different periods of time (48, 96 or 144 h) using the comet assay. Our results show that anthracene is genotoxic to T. carolinus and that DNA damage was dose-and depuration/time-dependent. Anthracene genotoxicity was observed in all experimental concentrations. Depuration seemed to be more efficient in fish exposed to the lowest anthracene concentration and maintained in clean water for 96 h. R E S U M OAmbientalmente, o antraceno é considerado persistente, bioacumulativo e tóxico para organismos aquáticos. A biotransformação de substâncias xenobióticas, como o antraceno, produz espécies reativas de oxigênio que podem agir sobre o DNA. O objetivo deste trabalho foi avaliar o dano ao DNA em T. carolinus expostos a diferentes concentrações de antraceno (8, 16 e 32 µg.L -1 ) por 24 h no escuro e subsequentemente mantidos em água limpa para depuração por três diferentes períodos de tempo (48, 96 e 144 h) através de ensaio cometa. Os resultados obtidos demonstram que o antraceno é genotóxico para T. carolinus e o dano ao DNA foi dose-e tempo de depuração-dependente. A genotoxicidade do antraceno foi detectada nas três concentrações utilizadas. A depuração pareceu ser mais eficiente nos peixes expostos a menor concentração de antraceno e mantidos por 96 h em água limpa.