The toxicity of silver nanomaterials (NM 300K) is reduced when combined with N-Acetylcysteine: Hazard assessment on Enchytraeus crypticus.

The widespread production and use of silver nanomaterials (AgNMs) in consumer and medical products have been raising environmental concerns. Once in the environment, the soil is one of the major sinks of AgNMs due to e.g. sewage sludge applications, and invertebrates are directly exposed. In this study, we investigate the potential of N-acetylcysteine (NAC) to reduce the toxic effects of Ag NM300 K (and AgNO3) on the soil invertebrate Enchytraeus crypticus. Ag NM300 K induces mortality, reproduction impairment, and avoidance. The addition of NAC to the soil showed a remarkable reduction in the toxicity of Ag, indicating that NAC can act as a detoxifying agent for terrestrial organisms exposed to Ag materials. That the reduction in toxicity likely is caused by thiol groups, was confirmed by GSH and GSSH studies. Identifying the mechanisms and hence alternatives that allow the recovery of contaminated soils is an important mitigation measure to promote environmental safety and reduce the associated risks to human health. Further, it may inform on strategies to implement in safe-by-design industry development.

Graphene-Based Nanomaterials in Soil: Ecotoxicity Assessment Using Enchytraeus crypticus Reduced Full Life Cycle.

Graphene-based nanomaterials (GBNs) possess unique physicochemical properties, allowing a wide range of applications in physical, chemical, and biomedical fields. Although GBNs are broadly used, information about their adverse effects on ecosystem health, especially in the terrestrial environment, is limited. Therefore, this study aims to assess the toxicity of two commonly used derivatives of GBNs, graphene oxide (GO) and reduced graphene oxide (rGO), in the soil invertebrate Enchytraeus crypticus using a reduced full life cycle test. At higher exposure concentrations, GO induced high mortality and severe impairment in the reproduction rate, while rGO showed little adverse effect up to 1000 mg/kg. Collectively, our body of results suggests that the degree of oxidation of GO correlates with their toxic effects on E. crypticus, which argues against generalization on GBNs ecotoxicity. Identifying the key factors affecting the toxicity of GBNs, including ecotoxicity, is urgent for the design of safe GBNs for commercial purposes.