abstract
In the last decade different approaches have been applied for water remediation purposes, including the use of nanoparticles (NPs) to remove metals and metalloids from water. Although studies have been done on the toxic impacts of such NPs, very scarce information is available on the impacts of water after decontamination when discharged into aquatic environments. As such, in the present study we aimed to evaluate the ecotoxicological safety of seawater previously contaminated with arsenic (As) and remediated by using manganese-ferrite (MnFe2O4-NPs) NPs. For this, mussels Mytilus galloprovincialis were exposed for 28 days to different conditions, including clean seawater (control), As (1000 mu g L-1) contaminated and remediated (As 70 mu g L-1) seawater, water containing MnFe2O4- NPs (50 mg L-1) with and without the presence of As. At the end of exposure, concentrations of As in mussels tissues were quantified and biomarkers related to mussels' metabolism and oxidative stress status were evaluated. Results revealed that mussels exposed to water contaminated with As and to As + NPs accumulated significantly more As (between 62% and 76% more) than those exposed to remediated seawater. Regarding biomarkers, our findings demonstrated that in comparison to remediated seawater (conditions a, b, c) mussels exposed to contaminated seawater (conditions A, B, C) presented significantly lower metabolic activity, lower expenditure of energy reserves, activation of antioxidant and biotransformation defences, higher lipids and protein damages and greater AChE inhibition. Furthermore, organisms exposed to As, NPs or As + NPs revealed similar biochemical effects, both before and after water decontamination. In conclusion, the present study suggests that seawater previously contaminated with As and remediated by MnFe2O4-NPs presented significantly lower toxicity than As contaminated water, evidencing the potential use of these NPs to remediate seawater contaminated with As and its safety towards marine systems after discharges to these environments.
keywords
TITANIUM-DIOXIDE NANOPARTICLES; WALLED CARBON NANOTUBES; OXIDATIVE STRESS; BIOACCUMULATION PATTERNS; PHOTOCATALYTIC OXIDATION; MNFE2O4 NANOPARTICLES; HEDISTE-DIVERSICOLOR; SILVER NANOPARTICLES; BIOCHEMICAL IMPACTS; OXIDE NANOPARTICLES
subject category
Environmental Sciences & Ecology; Public, Environmental & Occupational Health
authors
Coppola, F; Tavares, DS; Henriques, B; Monteiro, R; Trindade, T; Soares, AMVM; Figueira, E; Polese, G; Pereira, E; Freitas, R
our authors
Daniela Soraia dos Santos Tavares
PhD Student
Tito Trindade
Full professoracknowledgements
Francesca Coppola, Daniela S. Tavares and Rui Costa Monteiro benefited from PhD grants (SFRH/BD/118582/2016 SFRH/BD/103828/2014 and SFRH/BD/108535/2015, respectively), while Bruno Henriques benefited from postdoctoral grant (SFRH/BPD/112576/2015), given by the National Funds through the Portuguese Science Foundation (FCT), supported by FSE and Programa Operacional Capital Humano (POCH) e da Unido Europeia. Rosa Freitas benefited from a Research position funded by Integrated Programme of SR&TD Smart Valorization of Endogenous Marine Biological Resources Under a Changing Climate (reference Centro-01-0145-FEDER-000018), co-funded by Centro 2020 program, Portugal 2020, European Union, through the European Regional Development Fund. Thanks are due for the financial support to CESAM (UID/AMB/50017/2019), to FCT/MEC through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and COMPETE 2020. This work was also financially supported by the project BISPECIAl: BIvalveS under Polluted Environment and Climate chAnge (POCI-01-0145-FEDER-028425) funded by FEDER, through COMPETE2020 - Programa Operational Competitividade e Internacionalizacao (POCI), and by national funds (OE), through FCT/MCTES. Thanks are also due, for the financial support to CESAM (UID/AMB/50017), to FCT/MEC through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020.