Estimating Potential Life Cycle Releases of Engineered Nanomaterials from Wastewater Treatment Plants

In the absence of experimental data, a life cycle modeling approach can be used to predict engineered nanomaterial (ENM) concentrations in environmental media. Several such models have been created with various geographic scopes. This study presents an environmental release model that accounts for local differences in product consumption, wastewater treatment levels, waste incineration, and biosolids management and provides estimates of ENM release from wastewater treatment facilities in New York City, London, and Shanghai. The results illustrate how these local variations in model parameters contribute to differences in predicted ENM concentration in wastewater effluent and biosolids on a local level. Our analysis also takes a first step toward conducting a local-level risk assessment by providing the approximate locations and quantities of ENM discharge into aquatic systems. We find that there is significant uncertainty in model parameters that leads to a wide range of concentration estimates, yet we find that local variations in model parameters predict ENM concentration estimates that are within the same order of magnitude