Full life cycle test with Eisenia fetida - copper oxide NM toxicity assessment

• Published in: Ecotoxicology and environmental safety 2022-08, Vol.241, p.113720-113720, Article 113720
• Main Authors: Scott-Fordsmand, J.J., Irizar, A., Amorim, M.J.B.
• Format: Article
• Language: English
• Subjects: CuONM; Earthworms; Environment; Life stages; Population effect
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2022.113720

Copper oxide nanomaterials (CuONM) are widely used, e.g. as antimicrobial coatings, wood preservatives,fertilizers, etc. Life cycle aspects of Copper Nanomaterials (CuONM) toxicity have been scarcely studied in earthworms, as the focus has been on standard survival and reproduction toxicity tests. Standard tests do not allow for an understanding of which life cycle stage is the most sensitive, and how this can be impacted by CuONMs toxicity to cause longer term population level effects. Since CuONM may release free Cu ions (Cu2+) it is relevant to compare CuONM toxicity with CuCl2 salt. Therefore, the aim of the present study was to assess the effects of CuONM and CuCl2 throughout the different stages of the full life cycle (FLC) of Eisenia fetida while comparing it with the OECD standard test. Additional endpoints included juvenile survival, growth, maturation, besides survival and reproduction. The FLC test showed that e.g. juvenile survival was especially susceptible during the first 28 days post-hatching, neither juvenile growth nor time to maturity were related to exposure concentration. Both CuONM and CuCl2 caused a concentration-dependent decrease in population growth, while a hormesis effect was observed at low concentrations of CuCl2. A reduction in instantaneous growth rate was observed at higher concentrations. The FLC test and the OECD test had different exposure history therefore the ECx values are not comparable across the test systems. Hence, the FLC test enabled the detection of the most vulnerable developmental stages and elucidate different life stage sensitivities between the two Cu exposures. [Display omitted] •Current OECD standard test miss specificity in the life stage evaluation.•A specific life cycle (LC) test will provide a better environmental hazard assessment.•A LC test shows that life stages are affected by various Cu forms.•Different effects from LC include impact on hatching vs juvenile mortality.