A screening study on the fate of fullerenes (nC₆₀) and their toxic implications in natural freshwaters

Abstract

Increasing usage of fullerenes (C60 ) increases their opportunities to be released into the environment. For risk assessment, it is important to understand the environmental fate and ecotoxicological effects of C60 . In the present study, fullerene settling was measured during a 1-yr period with 4 different lake waters and an artificial freshwater, and Daphnia magna immobilization and fullerene accumulation was also measured in each of the lake waters. Depending on the characteristics of the lake waters, fullerenes either exhibited extended water stability or settled rapidly; in all waters, there was a fraction that remained stable after 1 yr. Water stability was affected by the quality and molecular size distribution of dissolved natural organic matter (DNOM). Increasing DNOM molecular sizes with high aromatic content enhanced water stability. Immobilization of D. magna was generally quite low (under 20%) and highly variable after 24 h and 48 h at initial fullerene concentrations up to 10 mg/L. Substantial settling occurred during the time period for acute toxicity assays (i.e., 48 h), which should be anticipated when conducting toxicity assays. There were no significant differences in the quantity of accumulated fullerenes among the different lake waters at fullerene concentrations of 0.5 mg/L, but there were differences at 2 mg/L.

Fullerenes(nC60) affect the growth and development of the sediment-dwelling invertebrate Chironomus riparius larvae

“…Benthic invertebrates are an important link between the sediment and other trophic levels. Additionally, small concentrations of fullerenes have been already measured from wastewater effluents (Farre et al, 2010) and sedimentation has also been shown to have an impact on NPs (Pakarinen et al, 2013;Quik et al, 2014). There are several factors which influences on the fate of NPs in the aquatic ecosystems like dissolved organic matter (DOM) or other natural particles Quik et al, 2012;Pakarinen et al, 2013).…”

“…Sediments are known to be a major sink of contaminants; this most likely applies to nanomaterials (NMs) as well (Pakarinen et al, 2013;Gottschalk et al, 2009). Benthic invertebrates are an important link between the sediment and other trophic levels.…”

The effect of humic acid on the aggregation of titanium dioxide nanoparticles under different pH and ionic strengths

“…The role of HA in nanoparticle transport is of particular interest. The fate of fullerenes (nC 60 ) and their toxic implications in natural freshwaters are affected by humic acid (Meng et al, 2013;Pakarinen et al, 2013), and humic acid is more effective than fulvic acid at stabilizing nC 60 nanoparticles . Humic acid affects the adsorption of other pollutants on the surface of multiwalled carbon nanotubes (MWCNTs) (Hou et al, 2013).…”

Colloidal stability of (functionalised) fullerenes in the presence of dissolved organic carbon and electrolytes

“…Recently, measurements of fullerene settling over a 1-year period with 4 natural DOC samples (hardness, [Ca 2+ + Mg 2+ ] = 0.10-0.33 mM) indicated that a higher colloidal stability of nC 60 correlated with more hydrophobic DOC. 33 This suggests that molecular properties of DOC such as aromaticity are important in the interactions between Environmental Science: Nano Paper DOC and fullerenes. The relatively high hydrophobicity of the DOC source used in this study is probably responsible for the sorption and subsequent stabilization of fullerenes at already relatively low DOC concentrations (2 mg C per L).…”