Premium
Fate of the Benzimidazole Antiparasitics Flubendazole and Fenbendazole in Manure and Manured Soils
Author(s) -
Kreuzig Robert,
Blümlein Katharina,
Höltge Sibylla
Publication year - 2007
Publication title -
clean – soil, air, water
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 66
eISSN - 1863-0669
pISSN - 1863-0650
DOI - 10.1002/clen.200720023
Subject(s) - fenbendazole , benzimidazole , manure , incubation , chemistry , soil water , zoology , metabolite , mineralization (soil science) , environmental chemistry , ecotoxicology , nitrogen , biology , agronomy , ecology , biochemistry , organic chemistry , anthelmintic
The fate of flubendazole and fenbendazole in manure and manured soils was investigated under laboratory and field conditions. In pig manure, both 14 C‐labeled benzimidazoles disappeared slowly. After a 102 day incubation period, extractable fractions contained 72% flubendazole or 80% fenbendazole of the radioactivity initially applied. The latter was accompanied by 4% of the corresponding metabolite fenbendazole‐sulfoxide. Non‐extractable residues amounted to 24 and 13%, respectively. On this basis, test manures with 7 day aged benzimidazole residues were prepared. Mobility tendencies differed for clay and sand soils as well as for standard and test‐manure application. Regarding K OC > 1100 L/kg, however, criteria for potential leachers were not fulfilled. The metabolic fate of flubendazole was predominated by the occurrence of the parent compound while fenbendazole was accompanied by fenbendazole‐sulfoxide. In clay soil samples after standard application, DT 50 values were 174 and 54 days, respectively. Mineralization and formation of non‐extractable residues were of minor relevance. For fenbendazole, these processes were intensified after test‐manure application. Due to enhanced formation of fenbendazole‐sulfoxide, fenbendazole‐sulfone, and non‐extractable residues, DT 50 thus dropped to 9 days. Similar mobility and degradability tendencies were also found under field conditions. In the sand soil, however, the metabolic dynamics decelerated due to its lower microbial activity.