Comparison of uptake and elimination kinetics of metallic oxide nanomaterials on the freshwater microcrustacean Daphnia magna

Abstract

The widespread use and release of nanomaterials (NMs) in aquatic ecosystems is a concerning issue as well as the fate and behavior of the NMs in relation to the aquatic organisms. In this work, the freshwater microcrustacean Daphnia magna was exposed to 12 different and well-known NMs under the same conditions for 24 h and then placed in clean media for 120 h, in order to determine their different uptake and elimination behaviors. The results showed that most of the tested NMs displayed a fast uptake during the first hours arriving to a plateau by the end of the uptake phase. The elimination behavior was determined by a fast loss of NMs during the first hours in the clean media, mainly stimulated by the presence of food. Remaining NMs concentrations can still be found at the end of the elimination phase. Two NMs had a different profile (i) ZnO-NM110 exhibited increase and loss during the uptake phase, and (ii) SiO₂-NM204 did not show any uptake. A toxicokinetic model was applied and the uptake and elimination rates were found along with the dynamic bioconcentration factors. These values allowed to compare the NMs, to cluster them by their similar rates, and to determine that the TiO₂-NM102 is the one that has the fastest uptake and elimination behavior, SiO₂-NM204 has the slowest uptake and CeO₂ <10 nm has the slowest elimination. The present work represents a first attempt to compare different NMs based on their uptake and elimination behaviors from a perspective of the nano-bio interactions influence.

Keywords:

• Daphnids
• nanomaterials
• uptake
• elimination
• toxicokinetics
• modeling

Acknowledgments

The authors thank the support of the French Ministry for the Ecological and Inclusive Transition. Special recognition is given to Arnaud Papin, to Farid Ait-Ben-Ahmad, and to Yohann Baillon for the access and assistance with the ICP-OES and ICP-MS instruments. And we express our gratitude for the counseling in the model application by Cléo Tebby and Aude Ratier.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data pertaining to this manuscript are deposited in figshare at https://doi.org/10.6084/m9.figshare.15098343.v1