Dietary toxicity of single-walled carbon nanotubes and fullerenes (C₆₀) in rainbow trout (<i>Oncorhynchus mykiss</i>)

The objective of this investigation was to compare the toxicity of two manufactured carbon nanomaterials (CNs) to determine if shape influenced toxicity. Juvenile rainbow trout Oncorhynchus mykiss were fed a control diet (no CN addition), or a diet supplemented with 500 mg single-walled carbon nanotubes (SWCNT) kg(-1) or 500 mg C(60) kg(-1) for six weeks. Fish growth, haematology, tissue ion concentrations, histopathology, osmoregulation, and biochemistry were evaluated. At week 4, but not on weeks 2 and 6, significant elevation in brain TBARS (an indication of lipid peroxidation) was observed in fish exposed to SWCNTs (16.2 ± 1.38 nmol mg(-1) protein) compared to the control (9.11 ± 0.81 nmol mg(-1) protein) and fish exposed to C(60) (8.28 ± 0.56 nmol mg(-1) protein). No other significant treatment-related differences were observed. Results indicate that dietary exposure to SWCNTs and C(60) in rainbow trout did not result in overt toxicity.