Suchergebnisse

Abstract
Background
Glyphosate is a broad-spectrum, non-selective systemic herbicide with a commonly assumed low potential for accumulation in biota. Nevertheless, glyphosate has been shown to bioaccumulate in the tissues of several organisms. To understand the bioconcentration dynamics of glyphosate in fish, brown trout (Salmo trutta forma fario) of different age were exposed to different concentrations of glyphosate, the formulation Roundup® LB Plus, and the major transformation product aminomethylphosphonic acid (AMPA) for two, three, or four weeks at different temperatures in the laboratory. Mortality rates were determined, and tissue samples were collected at the end of the experiment to ascertain concentrations of glyphosate and AMPA residues by liquid chromatography coupled to mass spectrometry (LC–MS/MS).

Results
Brown trout mortality during exposure to glyphosate or AMPA was considerably higher at 15 °C than at 7 °C. Also, a significant increase in glyphosate concentrations in samples containing muscle, head, backbone, and caudal fin tissue with increasing exposure concentrations and temperatures was observed. Six-month-old fish contained more glyphosate per kg wet weight after exposure than ten-month-old fish. The bioconcentration factors (BCFs) for glyphosate and AMPA were much higher at 15 °C than at 7 °C, but in both cases decreased with higher glyphosate concentrations. The BCF for glyphosate formulated in Roundup® was higher than the one for the parent compound. Approximately 30–42% of the organ-absorbed glyphosate and AMPA remained in the tissues even when the fish were kept in clean water lacking the test substances for three weeks after termination of exposure.

Conclusion
Our study demonstrated that there is an interaction between glyphosate and ambient temperature in terms of toxicity. Further it was shown that increasing concentrations of glyphosate and AMPA in the surrounding media lead to significantly increased concentrations of these substances in brown trout tissues, although neither bioconcentration nor bioaccumulation of glyphosate in animal tissues is expected due to the high water solubility of this chemical. As a consequence, the uptake of glyphosate by humans through the consumption of contaminated edible fish is very likely.

Die vorgestellte Arbeit ist Teil des BMBF-Verbundprojekts "SchussenAktivplus", das an den Bodenseezuflüssen Schussen und Argen durchgeführt wird. Die Kläranlage (KA) Langwiese bei Ravensburg, welche in die Schussen einleitet, wurde im Winter 2013 mit einer Pulveraktivkohlestufe aufgerüstet. Im hier vorgestellten Teil des Projektes wurde der Gesundheitszustand von Flohkrebsen (Gammarus spec.) und die Integrität der Makrozoobenthosgemeinschaft an Probestellen ober- und unterhalb der KA sowie vor und nach Ausbau der KA untersucht. Die Ergebnisse zeigen, dass sich der Ausbau der KA mit einer Pulveraktivkohlestufe bereits 15 Monate nach Einbau positiv auf den Gesundheitszustand von Flohkrebsen und die Artengemeinschaft des Makrozoobenthos auswirkt.