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Research article - Peer-reviewed, 2021

Effects of copper in Daphnia are modulated by nanosized titanium dioxide and natural organic matter: what is the impact of aging duration?

Roy, Rajdeep; Luederwald, Simon; Alawi Ahmed Maknoon, Asawer; Metreveli, George; Schulz, Ralf; Bundschuh, Mirco


During its aquatic life cycle, nanosized titanium dioxide (nTiO(2)) may interact with natural organic matter (NOM) ultimately altering the ecotoxicity of co-occurring chemical stressors such as heavy metals (e.g. copper (Cu)). In this context, the following hypotheses were tested: (1) aging of nTiO(2) along with Cu reduces Cu toxicity, (2) nTiO(2) agglomerates have a lower potential to reduce Cu toxicity and (3) aging of nTiO(2) in presence of NOM reduces Cu toxicity further. A multifactorial test design crossing three nTiO(2) levels (0.0, 0.6 and 3.0 mg/L) with two levels of NOM (0 versus 8 mg total organic carbon (TOC)/L) and seven nominal Cu concentrations (ranging from 0 to 1536 mu g/L) aged in ASTM medium for 0, 1, 3 and 6 days was realised, while two aging scenarios were applied (type 1: nTiO(2) jointly aged with Cu; type 2: Cu added after nTiO(2) aging). Subsequently, Cu toxicity was assessed using the immobility of Daphnia magna after 48 h of exposure as response variable. The experiments revealed that neither aging duration nor the extent of agglomeration (type 1 vs. type 2 aging) has a substantial impact on Cu induced toxicity. Moreover, it was confirmed that the presence of NOM substantially reduced Cu induced toxicity, independent of the aging scenario and duration. More importantly, the data suggest the ingestion of Cu loaded nTiO(2) as additional exposure pathway contributing to Cu toxicity. In conclusion, it seems unlikely that nTiO(2) concentrations currently detected in or predicted for aquatic ecosystems, which are at least one order of magnitude below the concentration tested here, influence Cu toxicity meaningfully.


Aging; Nanomaterials; Natural organic matter; Metal ions; Combined effect; Mixture toxicity

Published in

Environmental Science and Pollution Research
2021, volume: 28, number: 11, pages: 13991-13999

Authors' information

Roy, Rajdeep
University of Koblenz and Landau
Luederwald, Simon
University of Koblenz and Landau
Alawi Ahmed Maknoon, Asawer
University of Koblenz and Landau
Metreveli, George
University of Koblenz and Landau
Schulz, Ralf
University of Koblenz and Landau
Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment
University of Koblenz-Landau

UKÄ Subject classification

Environmental Sciences

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