Original Research ARTICLE
Ecotoxicological effects of chemical contaminants adsorbed to microplastics in the clam Scrobicularia plana
- 1Centre for Marine and Environmental Research (CIMA), University of the Algarve, Portugal
- 2University of Antwerp, Belgium
- 3Örebro University, Sweden
Although microplastics are distributed globally in the marine environment, a great deal of unknowns relating to their ecotoxicological effects on the marine biota remain. Due to their lipophilic nature, microplastics have the potential to adsorb persistent organic pollutants present in contaminated regions, which may increase their detrimental impact once assimilated by organisms. This study investigates the ecotoxicological effects of exposure to low-density polyethylene (LDPE) microplastics (11 – 13 µm), with and without adsorbed contaminants (benzo[a]pyrene - BaP and perfluorooctane sulfonic acid - PFOS), in the peppery furrow shell clam, Scrobicularia plana. Environmentally relevant concentrations of contaminants (BaP - 16.87±0.22 µg g-1 and PFOS - 70.22±12.41µg g-1) were adsorbed to microplastics to evaluate the potential role of plastic particles as a source of chemical contamination once ingested. S. plana were exposed to microplastics, at a concentration of 1 mg L-1, in a water-sediment exposure setup for 14 days. Clams were sampled at the beginning of the experiment (day 0) and after 3, 7 and 14 days. BaP accumulation, in whole clam tissues, was analysed. A multi-biomarker assessment was conducted in the gills, digestive gland, and haemolymph of clams to clarify the effects of exposure. This included the quantification of antioxidant (superoxide dismutase, catalase, glutathione peroxidase) and biotransformation (glutathione-S-transferases) enzyme activities, oxidative damage (lipid peroxidation levels), genotoxicity (single and double strand DNA breaks), and neurotoxicity (acetylcholinesterase activity). Results suggest a potential mechanical injury of gills caused by ingestion of microplastics that may also affect the analysed biomarkers. The digestive gland seems less affected by mechanical damage caused by virgin microplastic exposure, with the MP-adsorbed BaP and PFOS exerting a negative influence over the assessed biomarkers in this tissue.
Keywords: Polyethylene, Benzo-a-pyrene, perfluorooctane sulfonic acid, DNA Damage, Oxidative Stress, Neurotoxicity, oxidative damage.
Received: 15 Jan 2018;
Accepted: 10 Apr 2018.
Edited by:Ricardo Beiras, University of Vigo, Spain
Reviewed by:Leticia Vidal-Liñán, Instituto Español de Oceanografía (IEO), Spain
Juan Campillo, Instituto Español de Oceanografía (IEO), Spain
Copyright: © 2018 O'Donovan, Mestre, Abel, Fonseca, Carteny, Cormier, Keiter and Bebianno. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Maria Bebianno, University of the Algarve, Centre for Marine and Environmental Research (CIMA), Faro, Portugal, email@example.com