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  • 1.
    Fahlman, Johan
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Fick, Jerker
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Karlsson, Jan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Jonsson, Micael
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Brodin, Tomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Klaminder, Jonatan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Using laboratory incubations to predict the fate of pharmaceuticals in aquatic ecosystems2018Ingår i: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 15, nr 8, s. 463-471Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Environmental contextEnvironmental persistence of excreted pharmaceuticals in aquatic ecosystems is usually predicted using small-scale laboratory experiments assumed to simulate natural conditions. We studied five pharmaceuticals comparing their removal rates from water under laboratory conditions and under natural environmental conditions existing in a large pond. We found that the laboratory conditions did not fully capture the complexity within the pond, which led to different removal rates in the two systems. AbstractEnvironmental persistence is a key property when evaluating risks with excreted pharmaceuticals in aquatic ecosystems. Such persistence is typically predicted using small-scale laboratory incubations, but the variation in aquatic environments and scarcity of field studies to verify laboratory-based persistence estimates create uncertainties around the predictive power of these incubations. In this study we: (1) assess the persistence of five pharmaceuticals (diclofenac, diphenhydramine, hydroxyzine, trimethoprim and oxazepam) in laboratory experiments under different environmental conditions; and (2) use a three-month-long field study in an aquatic ecosystem to verify the laboratory-based persistence estimates. In our laboratory assays, we found that water temperature (TEMP), concentrations of organic solutes (TOC), presence of sediment (SED), and solar radiation (SOL) individually affected dissipation rates. Moreover, we identified rarely studied interaction effects between the treatments (i.e. SOLxSED and TEMPxSOL), which affected the persistence of the studied drugs. Half-lives obtained from the laboratory assays largely explained the dissipation rates during the first week of the field study. However, none of the applied models could accurately predict the long-term dissipation rates (month time-scale) from the water column. For example, the studied antibioticum (trimethoprim) and the anti-anxiety drug (oxazepam) remained at detectable levels in the aquatic environment long after (similar to 150 days) our laboratory based models predicted complete dissipation. We conclude that small-scale laboratory incubations seem sufficient to approximate the short-term (i.e. within a week) dissipation rate of drugs in aquatic ecosystems. However, this simplistic approach does not capture interacting environmental processes that preserve a fraction of the dissolved pharmaceuticals for months in natural water bodies.

  • 2.
    Heynen, Martina
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Brodin, Tomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Klaminder, Jonatan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Jonsson, Micael
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Fick, Jerker
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Tissue-specific uptake of the benzodiazepine oxazepam in adult Eurasian perch (Perca fluviatilis)2016Ingår i: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 13, nr 5, s. 849-853Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Psychoactive substances are used worldwide and constitute one of the common groups of pharmaceutical contaminants in surface waters. Typically, in field surveys and laboratory studies, muscle or whole - body homogenates are used to quantify pharmaceutical concentrations in biota, although uptake of pharmaceuticals may be tissue - specific. Therefore, the aim of this study was to investigate the tissue - specific (muscle, liver, brain and blood plasma) uptake of the anxiolytic oxazepam in adult Eurasian perch (Perca fluviatilis). In laboratory experiments, perch were exposed to four different concentrations (2, 4, 12 and 20 mu g L-1) of oxazepam for 6 days, and muscle, liver, brain tissue and blood plasma were sampled to determine tissue - specific bioconcentration. We found that the tissue - specific bioconcentration was independent of oxazepam concentration. However, among tissue types, bioconcentration was significantly different, with the concentration in muscle, liver = brain, blood plasma. Hence, it is important to consider the type of tissue used to quantify pharmaceutical uptake in fish, for predictions of species - specific sensitivity and comparisons across studies. Furthermore, our results indicate a somewhat lower transportability (brain/plasma ratio 0.54) of oxazepam from blood to brain in fish compared with in mammals, which should be kept in mind when employing 'read - across' approaches.

  • 3.
    Liem-Nguyen, Van
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Skyllberg, Ulf
    Nam, Kwangho
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Bjoern, Erik
    Thermodynamic stability of mercury(II) complexes formed with environmentally relevant low-molecular-mass thiols studied by competing ligand exchange and density functional theory2017Ingår i: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 14, nr 4, s. 243-253Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Inorganic divalent mercury (Hg-II) has a very high affinity for reduced sulfur functional groups. Reports from laboratory experiments suggest that Hg-II complexes with specific low-molecular-mass (LMM) thiol (RSH) ligands control rates of Hg-II transformation reactions. Because of methodological limitations for precise determination of the highly stable Hg-II complexes with LMM thiol ligands, constants reported in the literature remain inconsistent. This uncertainty impedes accurate modelling of the chemical speciation of Hg-II and the possibility to elucidate the role of Hg-II complexes with LMM thiols for Hg transformation reactions. Here, we report values of thermodynamic stability constants for 15 monodentate, two-coordinated Hg-II complexes, Hg(SR)(2), formed with biogeochemically relevant LMM thiol ligands. The constants were determined by a two-step ligand-exchange procedure where the specific Hg(SR)(2) complexes were quantified by liquid chromatography-inductively coupled plasma mass spectrometry. Thermodynamic stability constants (log (2)) determined for the Hg(SR)(2) complexes ranged from 34.6, N-cysteinylglycine, to 42.1, 3-mercaptopropionic acid, for the general reaction Hg2++2RS(-) Hg(SR)(2). Density functional theory (DFT) calculations showed that electron-donating carboxyl and carbonyl groups have a stabilising effect on the Hg-II-LMM thiol complexes, whereas electron-withdrawing protonated primary amino groups have a destabilising effect. Experimental results and DFT calculations demonstrated that the presence of such functional groups in the vicinity of the RSH group caused significant differences in the stability of Hg(SR)(2) complexes. These differences are expected to be important for the chemical speciation of Hg-II and its transformation reactions in environments where a multitude of LMM thiol compounds are present.

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