(510i) Characterization of Lethal Toxicity of Engineered Nanoparticles on Isochrysis Galbana Via Guts-Derived Fate-Transport-Effect Model

Ecotoxicological modeling is a crucial technique used in environmental risk assessments. Ecotoxicological models are used to determine the potential harms a proposed ecotoxicant can have on an ecosystem of interest. Fate ecotoxicological models make predictions on the distribution of ecotoxicants in an ecosystem. Toxicokinetic/toxicodynamic models make predictions on the effects of ecotoxicants on biota in an ecosystem. Models which link these two fields of ecotoxicological modeling are fate-transport-effect models. Dynamic biogeochemical mass-balances solved via numerical methods offer a robust approach to fate-transport-effect ecotoxicological modeling. We propose a biogeochemical modeling framework to bridge the gap between commonly used fate-transport models and toxicokinetic-toxicodynamic models using an extension of the GUTS toxicodynamic modelling framework. This model is then used to characterize the lethal toxicological effects of several metal engineered nanoparticles on a common marine alga, Isochrysis galbana. The model is also retroactively applied to two studies, one on the sub-lethal effects of engineered nanomaterials on Isochrysis galbana, another on the accumulation of 17α-ethinylestradiol in Desmodesmus subspicatus. In these analyses, we see the capacity of the model to descriptively characterize the population dynamics of microbial species, the accumulation of two classes of ecotoxicants in those microbes, and the toxicological effects of these ecotoxicants on the microbes.