Actions Speak Louder than Physicochemical Properties: Predicting nanomaterial behavior in agricultural systems by taking a holistic perspective
Tuesday, February 9, 2016
Amalia Turner is a CEE Graduate Student at Duke University.
Abstract: Functional assays (FAs) have been proposed as a way to overcome the challenges associated with predicting the behavior of engineered nanomaterials (ENMs) in complex systems. FAs bridge the gap between the physicochemical properties of ENMs and their impacts on potential receptors. Much like determining the octanol:water partition coefficient for organic chemicals, ENM FAs are relatively simple experiments that generate quantitative data on ENM behavior in systems of interest without requiring the complete understanding of all of the mechanisms involved. One example of a potential FA is a batch mixing study used to determine the degree to which ENMs will stick to available surfaces; the complexity of the system into which ENMs are introduced can range from natural soils, sediments, or biosolids slurries to glass beads with or without organic or inorganic amendments. The parameter empirically derived from this FA is a system-specific stickiness coefficient, or alpha (α), which has important implications for ENM mobility. I am currently designing experiments to probe the utility of α tests as FAs for predicting the degree of phyto-availability and phyto-accumulation of ENMs in agricultural settings. The flexibility of this method is ideal both for informing decision-making in the near term, primarily through incorporation into screening methods or predictive modeling, and developing hypotheses for further mechanistic study in the long term.