Browsing by Author "Silva, Sofia"
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- Biomarker responses of the clam ruditapes decussatus exposed to a complex mixture of environmental stressors under the influence of an urban wastewater-treatment plantPublication . Silva, Sofia; Cravo, Alexandra; Ferreira, Cristina; Correia, Cátia; Almeida, Cristina M. M.To evaluate the potential impact of an urban wastewater-treatment plant on Ria Formosa coastal lagoon, a sentinel species, the clam Ruditapes decussatus, was exposed along a gradient of the effluent's dispersal for 1 mo. Three exposure sites were selected to study the responses of 3 biomarkers: electron transport system, acetylcholinesterase, and lipid peroxidation. As complementary data, morphometric measurements, condition index, and lipid and protein content were considered together with in situ physicochemical characterization of the sites (temperature, salinity, pH, and dissolved oxygen). Electron transport system activity levels were between 35.7 and 50.5 nmol O-2/min g protein, acetylcholinesterase activity levels ranged from 2.6 to 3.8 nmol/min g protein, and lipid peroxidation ranged from 174.7 to 246.4 nmol malondialdehyde/g protein. The exposure sites shaped the response not only of biomarkers but also of "health" parameters (protein, lipids, and condition index). Lipid peroxidation was the most responsive biomarker also associated with electron transport system, especially at the closest site to the urban wastewater-treatment plant. Because of the presence of complex mixtures of contaminants in urban effluents, biomarker responses can provide valuable information in environmental assessment. However, it is vital to identify all biological and ecological factors induced by the natural life cycle of clams. Abiotic factors can mask or overlap the response of biomarkers and should be considered in a multibiomarker approach. (C) 2020 SETAC
- Development of a multiresidue method for the determination of 24 pharmaceuticals in clams by QuEChERS and liquid chromatography-triple quadrupole tandem mass spectrometryPublication . Rodrigues, Joao; Albino, Stephanie; Silva, Sofia; Cravo, Alexandra; Cardoso, Vitor Vale; Benoliel, Maria Joao; Almeida, Cristina M. M.Data on different therapeutic classes of pharmaceutical compounds (PhCs) in clams or other bivalves living in natural conditions are scarce. The aim of this work was the optimization and validation of a method for the determination of PhCs in clams for further evaluation of any potential human exposure risk due to their consumption. A quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach is proposed for sample clean-up and concentration of 24 PhCs in clams, with subsequent analysis by liquid chromatography-tandem mass spectrometry. This method showed a good linear range for all PhCs with determination coefficients (r(2)) between 0.9949 and 0.9993 and coefficients of variation (CVm) lower than 5.5%. This method allowed the quantification of target compounds at trace concentration levels (ngg(-1)), being the most abundant PhC in clam caffeine. This PhC was detected in more than 70% of samples with concentrations ranging from 0.10 to 12ngg(-1) wet weight.
- Understanding the bioaccumulation of pharmaceutical active compounds by clams Ruditapes decussatus exposed to a UWWTP dischargePublication . Cravo, Alexandra; Silva, Sofia; Rodrigues, João; Cardoso, Vítor Vale; Benoliel, Maria João; Correia, Cátia; Coelho, Maria Rosário; Rosa, Maria João; Almeida, Cristina M.M.Twenty-four pharmaceutical active compounds (PhACs) were evaluated in the soft tissues of clams Ruditappes decussatus exposed along a 1.5-km dispersal gradient of the treated effluent from an urban wastewater treatment plant discharging in Ria Formosa, and compared with those in the marine waters and discharged effluents. The clams were exposed for 1 month, in June-July 2016, 2017 and 2018. PhACs were quantified by high performance liquid chromatography coupled to tandem mass spectrometry after the quick, easy, cheap, effective, rugged and safe (QuEChERS) method (clams) or solid-phase extraction (water samples). The most representative PhACs in the effluents and receiving waters (regardless of the tidal dilution effect) were diclofenac, carbamazepine and caffeine (on average <= 2 mu g/L) and only caffeine exhibited significant inter-annual differences, with higher values in 2017. In turn, the most bioaccumulated PhACs in clams were caffeine (0.54-27 ng/g wet weight, significantly higher in 2016) and acetaminophen (0.37-3.7 ng/g wet weight, significant lower in 2016). A multivariate principal component analysis showed (i) PhAC bioaccumulation primarily depended on biotic factors (clams length and weight), (ii) PhAC physicochemical properties Log Kow, pKa and water solubility interplaying with water abiotic variables were more relevant for explaining data variability in water than the physical dilution/tidal mixing, (iii) this process, reflected by the salinity gradient, had a tertiary role in data variation, responsible for spatial discrimination of marine waters. This study provides a better understanding of PhACs bioaccumulation by clams Ruditapes decussatus in real environmental conditions, under the influence of urban treated effluent dispersal in Ria Formosa coastal lagoon, a major producer of bivalves, ultimately disentangling key factors of PhAC bioaccumulation.