title: Accumulation and distribution of multiwalled carbon nanotubes in zebrafish (Danio rerio).
abstract: No data on the bioaccumulation and distribution of multiwalled carbon nanotubes (MWCNTs) in aquatic vertebrates is available until now. We quantified uptake and elimination of dispersed radiolabeled MWCNTs ((14)C-MWCNT; 1 mg/L) by zebrafish (Danio rerio) over time. The influences of the feeding regime and presence of dissolved organic carbon (DOC) on accumulation of the nanomaterial were determined. The partitioning of radioactivity to different organs and tissues was measured in all experiments. A bioaccumulation factor of 16 L/kg fish wet weight was derived. MWCNTs quickly associated with the fish, and steady state was reached within 1 day. After transfer to clear medium, MWCNTs were quickly released to the water phase, but on average 5 mg of MWCNTs/kg fish dry weight remained associated with the fish. The nanomaterial mainly accumulated in the gut of all fish. Feeding led to lower internal concentrations due to facilitated elimination via the digestive tract. In the presence of DOC, 10-fold less was taken up by the fish after 48 h of exposure compared to without DOC. Quick adhesion to and detachment from superficial tissues were observed. Remarkably, little fractions of the internalized radioactivity were detected in the blood and muscle tissue of exposed fish. The part accumulated in these fish compartments remained constant during the elimination phase. Hence, biomagnification of MWCNTs in the food chain is possible and should be a subject of further research.
authors.affiliation: Institute for Environmental Research (Biology V), RWTH Aachen University , Worringerweg 1, 52074 Aachen, Germany.
authors.forename: Hanna M
authors.initials: HM
authors.lastname: Maes
authors.forename: Felix
authors.initials: F
authors.lastname: Stibany
authors.forename: Sebastian
authors.initials: S
authors.lastname: Giefers
authors.forename: Benjamin
authors.initials: B
authors.lastname: Daniels
authors.forename: Björn
authors.initials: B
authors.lastname: Deutschmann
authors.forename: Werner
authors.initials: W
authors.lastname: Baumgartner
authors.forename: Andreas
authors.initials: A
authors.lastname: Schäffer
mesh_terms: D000818:Animals; D005260:Female; D020387:Food Chain; D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D015027:Zebrafish / Q000378:metabolism*
chemical_list: D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical