Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1897/08-339.1
Volltext Shareable Link
Titel (primär) Chronic toxicity of five structurally diverse demethylase-inhibiting fungicides to the crustacean Daphnia magna: a comparative assessment
Autor Hassold, E.; Backhaus, T.
Quelle Environmental Toxicology and Chemistry
Erscheinungsjahr 2009
Department OEKOTOX
Band/Volume 28
Heft 6
Seite von 1218
Seite bis 1226
Sprache englisch
Keywords Fungicides; Daphnia magna; Ecdysteroid-related toxicity; Embryo toxicity; Eye malformations
Abstract Demethylase inhibitors (DMIs) are broad-spectrum fungicides that are ubiquitously used in agriculture and medicine. They comprise chemically heterogeneous substances that share a common biochemical target in fungi, the inhibition of a specific step in sterol biosynthesis. Several DMIs are suspected to disrupt endocrine-mediated processes in a range of organisms and to inhibit ecdysteroid biosynthesis in arthropods. It is unclear, however, whether and, if so, to what extent different DMI fungicides have a similar mode of action in nontarget organisms, which in turn would lead to a common chronic toxicity profile. Therefore, we selected a representative of each of the major DMI classes-the piperazine triforine, the pyrimidine fenarimol, the pyridine pyrifenox, the imidazole prochloraz, and the triazole triadimefon-and comparatively investigated their chronic toxicity to Daphnia magna. No toxicity was detectable up to the limit of solubility of triforine (61 mu mol/L). All other DMIs reduced reproductive success by delaying molting and development and by causing severe developmental abnormalities among offspring. Prochloraz was most toxic (median effective concentration [EC50] for fecundity reduction, 0.76 mu mol/L), followed by fenarimol (EC50, 1.14 mu mol/L), pyrifenox (EC50, 3.15 mu mol/L), and triadimefon (EC50, 5.13 mu mol/L). Mean effect concentrations for fecundity reduction were related to lipophilicity and followed baseline toxicity. However, triadimefon and fenarimol (but none of the other tested DMIs) caused severe eye malformations among exposed offspring. Affected neonates did survive, but a reduced ecological fitness can be assumed. Offspring exposed to fenarimol in mater matured earlier. The investigated different life-history parameters were affected in a substance-specific manner. These qualitatively different toxicity profiles suggest additional, substance-specific mechanisms of action in D. magna that probably are related to an antiecdysteroid action
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=240
Hassold, E., Backhaus, T. (2009):
Chronic toxicity of five structurally diverse demethylase-inhibiting fungicides to the crustacean Daphnia magna: a comparative assessment
Environ. Toxicol. Chem. 28 (6), 1218 - 1226 10.1897/08-339.1