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Trophic Transfer and Accumulation of Multiwalled Carbon Nanotubes in the Presence of Copper Ions in Daphnia magna and Fathead Minnow (Pimephales promelas)
journal contribution
posted on 2017-12-20, 00:00 authored by Amanda
M. Cano, Jonathan D. Maul, Mohammad Saed, Fahmida Irin, Smit A. Shah, Micah J. Green, Amanda D. French, David M. Klein, Jordan Crago, Jaclyn E. Cañas-CarrellThe
increase in use of nanomaterials such as multiwalled carbon
nanotubes (MWCNTs) presents a need to study their interactions with
the environment. Trophic transfer was measured between Daphnia
magna and Pimephales promelas (fathead minnow,
FHM) exposed to MWCNTs with different outer diameter (OD) sizes (MWCNT1
= 8–15 nm OD and MWCNT2 = 20–30 nm OD) in the presence
and absence of copper. Pristine FHM were fed D. magna, previously exposed for 3 d to MWCNT1 or MWCNT2 (0.1 mg/L) and copper
(0.01 mg/L), for 7 d. D. magna bioaccumulated less
MWCNT1 (0.02 μg/g) than MWCNT2 (0.06 μg/g), whereas FHM
accumulated more MWCNT1 (0.81 μg/g) than MWCNT2 (0.04 μg/g).
In the presence of copper, MWCNT bioaccumulation showed an opposite
trend. Mostly MWCNT1 (0.03 μg/g) bioaccumulated in D.
magna, however less MWCNT1 (0.21 μg/g) than MWCNT2
(0.32 μg/g) bioaccumulated in FHM. Bioaccumulation factors were
higher for MWCNT1s than MWCNT2. However, an opposite trend was observed
when copper was added. Plasma metallothionein-2 was measured among
treatments; however concentrations were not statistically different
from the control. This study demonstrates that trophic transfer of
MWCNTs is possible in the aquatic environment and further exploration
with mixtures can strengthen the understanding of MWCNT environmental
behavior.