Annika Batel, Flora Borchert, Hannes Reinwald, Lothar Erdinger, Thomas Braunbeck

Environmental Pollution, Volume 235, 2018, Pages 918-930, ISSN 0269-7491,

Abstract:

Since only a few studies have investigated effects of
microplastics (MPs) by routes other than ingestion, this study was
designed to analyze the accumulation patterns and transfer of toxic
substances associated with microplastic exposure by simple attachment to
(1) adult zebrafish (Danio rerio) gills and (2) zebrafish embryos. Two
sizes of fluorescently labelled polymers (1–5 and 10–20 μm) loaded with
the model polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (BaP)
were used to analyze fate, accumulation and transfer of
microplastic-associated persistent organic pollutants (POPs) on gills
and embryos. Results indicate that microplastics did not permanently
accumulate at high amounts in adult zebrafish gills after 6 nor 24 h of
incubation: Most particles only superficially adhered to the mucus layer
on the filaments, which is constantly being excreted. In contrast, the
smaller and heavier MPs (1–5 μm) accumulated in high numbers on the
surface of zebrafish egg chorions. In both exposure scenarios, transfer
of BaP could be visualized with fluorescence microscopy: A prominent BaP
signal was visible both in gill filaments and arches after 6 and 24 h
incubation and in zebrafish embryos after exposure to BaP-spiked
microplastics. Furthermore, the gill EROD (Ethoxyresorufin-O-deethylase)
assay showed a clear trend to CYP 1A (Cytochrom P450 1 A) induction via
exposure to BaP-spiked microplastics. However, BaP from spiked
microplastics did not reach sufficiently high concentrations to be able
to induce morphological effects in the fish embryo toxicity test (FET).
In contrast, control exposure to waterborne BaP did induce effects in
the FET. As a conclusion, microplastics can also transfer POPs not only
via ingestion, but also by simple attachment to epithelia or via the
water column. However, further studies are needed to clarify if these
interactions are of environmental concern relative to waterborne
exposure to toxic substances.

https://drive.google.com/open?id=1H6Nft11eKPBhjAVwsTQI2cDHgT6sqFVb

https://doi.org/10.1016/j.envpol.2018.01.028.(http://www.sciencedirect.com/science/article/pii/S0269749117336801)