Multimedia Environmental Distribution of Engineered Nanomaterials

Abstract

A compartmental multimedia model was developed to enable evaluation of the dynamic environmental multimedia mass distribution and concentrations of engineered nanomaterials (ENMs). The approach considers the environment as a collection of compartments, linked via fundamental environmental intermedia transport processes. Model simulations for various environmental scenarios indicated that ENM accumulation in the sediment increased significantly with increased ENMs attachment to suspended solids in water. Atmospheric dry and wet depositions can be important pathways for ENMs input to the terrestrial environment in the absence of direct and distributed ENM release to soil. Increased ENM concentration in water due to atmospheric deposition (wet and dry) is expected as direct ENM release to water diminishes. However, for soluble ENMs dissolution can be the dominant pathway for suspended ENM removal from water even compared to advection. Mass accumulation in the multimedia environment for the evaluated ENMs (metal, metal oxides, carbon nanotubes (CNT), nanoclays) was mostly in the soil and sediment. The present modeling approach, as illustrated via different test cases, is suited for "what if" first tier analyses to assess the multimedia mass distribution of ENMs and associated potential exposure concentrations.

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

“…10−12,37,46−50 Both steady-state fate and transport (FT) models and MFAs cannot predict the dynamic long-term environmental distribution of ENMs or easily account for variations in climate and hydrology. 37,47,48 Examples of all three model approaches as applied to ENMs are given in Table S1.…”

“…[10][11][12]46,52,53,63,64 Since nanoFate falls within the multimedia models, we discuss the differences with similar models (i.e., MendNano and SimpleBox4Nano) in more detail. 47,48 MendNano includes air, water, soil, sediment, and terrestrial and aquatic biota. However, the model is limited with regards to mass transfer processes between soil and water, uses simplified ENM transformation processes, excludes climate variability, and does not make distinctions between subcompartments within each major compartment (for example, soil solids and soil water within soil).…”

Freshwater ecotoxicity characterisation factor for metal oxide nanoparticles: A case study on titanium dioxide nanoparticle

“…The development of freshwater-ecotoxicity CFs for ENPs is still in its infancy due to the scarce knowledge of the exposure and effects to aquatic organisms. More fate and transport models (F&T) to assess the concentration of ENPs in the environmental media are yet to emerge (Liu and Cohen, 2014;Gottschalk et al, 2010;Gottschalk et al, 2013). It is evident that the lack of ecotoxicity CF of ENPs impedes the evaluation of ecotoxicological impacts caused by their emissions into the environment.…”

The bioavailability and toxicity of ZnO and Ni nanoparticles and their bulk counterparts in different sediments

“…The research shows (e.g., Coutris et al 2012;Jośko and Oleszczuk 2013) that this is an important factor in determining the toxicity of NPs in soils. Evaluation of the influence of aging on the toxicity of NPs is especially justified in benthic sediments due to a much longer retention time of NPs in these sediments compared to other environments (Liu and Cohen 2014). The existing studies have been conducted on sediments recently contaminated by NPs (e.g., Fabrega et al 2012;Hanna et al 2013), which may not reflect the actual conditions experienced in many natural environments.…”