Vignardi C. P. auteur aut IRD Adeleye A. S. auteur aut IRD Kayal Mohsen auteur aut IRD Oranu E. auteur aut IRD Miller R. J. auteur aut IRD Keller A. A. auteur aut IRD Holden P. A. auteur aut IRD Lenihan H. S. auteur aut IRD text journalArticle eng text/pdf born digital access Environmental conditions in aquatic ecosystems transform toxic chemicals over time, influencing their bioavailability and toxicity. Using an environmentally relevant methodology, we tested how exposure to seawater for 1-15 weeks influenced the accumulation and toxicity of copper nanoparticles (nano-Cu) in a marine phytoplankton species. Nano-Cu rapidly agglomerated in seawater and then decreased in size due to Cu dissolution. Dissolution rates declined during weeks 1-4 and remained low until 15 weeks, when the large agglomerates that had formed began to rapidly dissolve again. Marine phytoplankton species were exposed for 5-day periods to nano-Cu aged from 1 to 15 weeks at concentrations from 0.01 to 20 ppm. Toxicity to phytoplankton, measured as change in population growth rate, decreased significantly with particle aging from 0 to 4 weeks but increased substantially in the 15-week treatment due apparently to elevated Cu dissolution of reagglomerated particles. Results indicate that the transformation, fate, and toxicity of nano-Cu in marine ecosystems are influenced by a highly dynamic physicochemical aging process. specialized engineered nanomaterials environmental conditions aging copper nanoparticles marine phytoplankton ecotoxicity 038 021 034 57 17 6989-6998 2023 0013-936X https://www.documentation.ird.fr/hor/fdi:010087714 10.1021/acs.est.2c07953 0013-936X [F B010087714] https://www.documentation.ird.fr/hor/fdi:010087714 https://www.documentation.ird.fr/intranet/publi/2023-06/010087714.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2023-06-30 2023-06-30 fdi:010087714 fre