Effects of iron oxide nanoparticles (Fe3O4) on life history and metabolism of the Neotropical cladoceran Ceriodaphnia silvestrii

Author(s)

Gebara, Renan Castelhano ^{[1, 2]} ; Souza, Jaqueline Perola ^[3] ; Mansano, Adrislaine da Silva ^[3] ; Sarmento, Hugo ^{[1, 2]} ; Gama Melao, Maria da Graca ^{[1, 2]}

Affiliation

^[1] Univ Fed Sao Carlos UFSCar, Postgrad Program Ecol & Nat Resources PPGERN, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos UFSCar, Dept Hydrobiol, Rodovia Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Sao Paulo, Nanomed & Nanotoxicol Grp, Phys Inst Sao Carlos IFSC, Ave Trabalhador Saocarlense 400, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY; v. 186, DEC 30 2019.
• Web of Science Citations: 0

Abstract

Nanoparticles (NPs) production is increasing worldwide. These products are likely to end up in aquatic environments. However, few studies evaluated the chronic toxicity of iron-based NPs (Fe-NPs) to cladocerans and their potential ecotoxicological hazards. In this study we aimed to investigate the effects of iron oxide nanoparticles (Fe3O4-NPs) to Ceriodaphnia silvestrii Daday, 1902, assessing acute (48 h) and chronic toxicity (up to 14 d). Besides traditional endpoints (immobility and lethality), we also evaluated physiological responses (respiration rates) in a 48 h-exposure. No immobility was observed (EC50 > 100 mg L-1) after 48 h, whereas respiration rates at the highest concentration were 400% of that in control, indicating that this endpoint was more sensitive during acute toxicity. In chronic assays, Fe3O4-NPs affected body length (8.24% growth inhibition in 7 d-exposure) and number of eggs (7-d IC10: 3.53, IC20: 6.69 mg Fe L-1) and neonates (7-d IC10: 1.25, IC20: 3.75 mg Fe L-1). Based on species sensitivity distribution (SSD), C. silvestrii was a sensitive organism, suggesting Fe-NPs as a possible threat for this species. Our results also indicate that the NPs caused a physical barrier, impairing food absorption, since we observed NPs agglomerations into cladocerans' gut. We demonstrate that Fe3O4-NPs affects C. silvestrii metabolism and reproduction and our results support the use of sublethal endpoints to assess environmental safety. The release of these NPs into freshwater environments should be carefully evaluated, since disturbances on cladoceran population dynamics could cause strong impacts on the entire food web structure and ultimately on ecosystem functioning. (AU)

• FAPESP's process: 16/00753-7 - Toxic effects of emerging microcontaminants on planktonic food webs
• Grantee: Maria da Graça Gama Melão
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/14139-3 - Microbial processes and biodiversity in aquatic ecosystems
• Grantee: Hugo Miguel Preto de Morais Sarmento
• Support Opportunities: Research Grants - Young Investigators Grants