Multigeneration impacts on Daphnia magna of carbon nanomaterials with differing core structures and functionalizations

Several classes of contaminants have been shown to have multigenerational impacts once a parental generation has been exposed. Acute and chronic toxicity are described for several types of nanomaterials in the literature; however, no information is available on the impact of nanomaterials on future generations of organisms after the exposure is removed. In the present study, the authors examined the impacts of carbon nanomaterials (CNMs), including fullerenes (C-60), single-walled carbon nanotubes (SWCNTs), and multiwalled carbon nanotubes (MWCNTs) with neutral, positive, and negative functional groups to F-1 and F-2 generation daphnids after an F-0 exposure. Data from the present study indicate that multigenerational toxicity is present with certain nanomaterial exposures and is highly dependent on the surface chemistry of the nanomaterial. Many CNMs that showed toxicity to exposed F-0 daphnids in previous experiments did not induce multigenerational toxicity. Certain nanomaterials, however, such as C-60-malonate, SWCNTs, SWCNT-CONH2, and MWCNTs, caused a significant decrease in either survival or reproduction in F-1 daphnids; and SWCNT-CONH2 decreased reproduction out to the F-2 generation. Impacts of nanomaterials on F-1 and F-2 size were small and lacked clear patterns, indicating that CNMs have minimal multigenerational impacts on size. Industries should take into account how surface chemistry influences nanomaterial toxicity to future generations of organisms to create sustainable nanomaterials that do not harm freshwater ecosystems. Environ Toxicol Chem 2014;33:541-547. (c) 2013 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.