Aqueous fullerene aggregates (nC60) generate minimal reactive oxygen species and are of low toxicity in fish: a revision of previous reports

This review aims to clarify inconsistencies in previous reports regarding the potential for aqueous aggregates of fullerenes (nC60) to generate reactive oxygen species (ROS) and cause toxicity in fish. Methods for evaluation of ROS production and toxicity of aqueous nC60 have evolved over time and limitations in initial studies have led to unintentional erroneous reports of nC60 ROS generation and toxicity. Some of these reports continue to lead to misconceptions of the environmental effects of C60. Critical review of the evidence (2007–2011) indicates that aqueous nC60 have minimal potential to produce ROS and that oxidative stress in fish is not induced by environmentally relevant exposure to nC60. Future studies should acknowledge that current evidence indicates low toxicity of nC60 and refrain from citing articles that attribute toxicity in fish to nC60 based on methods shown to be compromised by experimental artifacts. Despite low toxicity of nC60 in fish, an emerging environmental issue is that nC60 can affect environmental fate, transport, and bioavailability of co-contaminants in aquatic environments in a similar manner to that observed for other anthropogenic particulates (e.g., microplastics).

► Misconceptions of aqueous aggregates of fullerene C60 (nC60) effects are addressed.
► Some previous studies are compromised by unintentional experimental artifacts.
► Aqueous nC60 generate minimal reactive oxygen species.
► Aqueous nC60 are of low toxicity in fish.
► Association of toxicants (co-contaminants) with nC60 recognized as important effect.