Modeled Environmental Concentrations of Engineered Nanomaterials (TiO₂, ZnO, Ag, CNT, Fullerenes) for Different Regions

Abstract

Engineered nanomaterials (ENM) are already used in many products and consequently released into environmental compartments. In this study, we calculated predicted environmental concentrations (PEC) based on a probabilistic material flow analysis from a life-cycle perspective of ENM-containing products. We modeled nano-TiO(2), nano-ZnO, nano-Ag, carbon nanotubes (CNT), and fullerenes for the U.S., Europe and Switzerland. The environmental concentrations were calculated as probabilistic density functions and were compared to data from ecotoxicological studies. The simulated modes (most frequent values) range from 0.003 ng L(-1) (fullerenes) to 21 ng L(-1) (nano-TiO(2)) for surface waters and from 4 ng L(-1) (fullerenes) to 4 microg L(-1) (nano-TiO(2)) for sewage treatment effluents. For Europe and the U.S., the annual increase of ENMs on sludge-treated soil ranges from 1 ng kg(-1) for fullerenes to 89 microg kg(-1) for nano-TiO(2). The results of this study indicate that risks to aquatic organisms may currently emanate from nano-Ag, nano-TiO(2), and nano-ZnO in sewage treatment effluents for all considered regions and for nano-Ag in surface waters. For the other environmental compartments for which ecotoxicological data were available, no risks to organisms are presently expected.

Stable silver isotope fractionation in the natural transformation process of silver nanoparticles

“…Ag is highly reactive and may be involved in natural processes such as oxidation, sulfidation and precipitation. Taking into account the significant Ag isotope fractionation observed here and the increasing levels of AgNPs discharged into the environment 3,4 , it is possible to infer that natural transformation processes of AgNPs may play an important role in natural Ag isotope fractionation.…”

“…An exponential increase in the environmental levels of AgNPs is predicted due to their rising usage and disposal levels 3,4 . As the natural abundance of Ag in the Earth's crust is extremely low (∼0.07 mg kg -1 ; ref.…”

“…Furthermore, the Ag isotope fractionation resulting from the photoreduction of Ag salts was also investigated to investigate the photosensitivity of Ag. Black Ag 0 precipitation (non-nanosized without the feature surface plasmon resonance of AgNPs in absorption spectra) was observed when AgClO 4 and AgNO 3 solutions were exposed to sunlight. The photoreduction of Ag salts caused the remaining Ag + to be enriched in 107 adsorption and the photoreduction of Ag salts are discussed in Supplementary Section 2.1.…”

“…*P < 10 −2 ; **P < 10 −2 . Aqueous solutions of AgClO 4 and AgNO 3 (200 mg l -1 ) were exposed to sunlight for two weeks and then the isotope ratios of the residual Ag + and Ag 0 precipitates were measured. The percentages in parentheses represent the relative fraction of Ag + reacted (that is, the percentages of photoreduced Ag + ).…”

Soil pH effects on the interactions between dissolved zinc, non-nano- and nano-ZnO with soil bacterial communities

“…sun screen, toothpaste) to antifouling paints, textiles, food additives, antibacterial 4 agents and environmental remediation processes (Lopes et al 2014). As a result, sewage treatment 5 works have been identified as having a high potential burden, with sludge containing up to 17.1 mg/kg 6 dry weight (dw) followed by sewage sludge treated soils with 3.25 mg/kg dw (compared to average 7 soil concentrations predicted to be around 0.093 mg/kg dw) (Gottschalk et al 2009). However oxidation of proteins, interruption of energy transduction and photo catalytic oxidation (Gou et al 16 2010, Klaine et al 2008).…”