Assessing the Risk of Engineered Nanomaterials in the Environment: Development and Application of the nanoFate Model

TLDR

The study develops the nanoFate model to predict time‑dependent accumulation of metallic engineered nanomaterials across environmental media. nanoFate incorporates diverse processes and subcompartments, simulating decade‑long releases of CeO₂, CuO, TiO₂, and ZnO in the San Francisco Bay area to capture spatially varying use and disposal patterns. Simulations show that soluble metal‑oxide ENMs can accumulate to potentially toxic levels in freshwater and soils—especially TiO₂ and ZnO—with weather and release variability driving acute concentrations, and that most ENMs remain aggregated or dissolved in agricultural, freshwater, or marine sediments, underscoring the influence of climate, release patterns, and compartment composition.

Abstract

We developed a dynamic multimedia fate and transport model (nanoFate) to predict the time-dependent accumulation of metallic engineered nanomaterials (ENMs) across environmental media. nanoFate considers a wider range of processes and environmental subcompartments than most previous models and considers ENM releases to compartments (e.g., urban, agriculture) in a manner that reflects their different patterns of use and disposal. As an example, we simulated ten years of release of nano CeO2, CuO, TiO2, and ZnO in the San Francisco Bay area. Results show that even soluble metal oxide ENMs may accumulate as nanoparticles in the environment in sufficient concentrations to exceed the minimum toxic threshold in freshwater and some soils, though this is more likely with high-production ENMs such as TiO2 and ZnO. Fluctuations in weather and release scenario may lead to circumstances where predicted ENM concentrations approach acute toxic concentrations. The fate of these ENMs is to mostly remain either aggregated or dissolved in agricultural lands receiving biosolids and in freshwater or marine sediments. Comparison to previous studies indicates the importance of some key model aspects including climatic and temporal variations, how ENMs may be released into the environment, and the effect of compartment composition on predicted concentrations.