TY  - JOUR
AU  - Laabs, V.
AU  - Wehrhan, A.
AU  - Pinto, A.
AU  - Dores, E.
AU  - Amelung, W.
TI  - Pesticide fate in tropical wetlands of Brazil: An aquatic microcosm study under semi-field conditions
JO  - Chemosphere
VL  - 67
SN  - 0045-6535
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - PreJuSER-57152
SP  - 975 - 989
PY  - 2007
N1  - Record converted from VDB: 12.11.2012
AB  - A contamination of off-site aquatic environments with pesticides has been observed in the tropics, yet only sparse information exists about pesticide fate in such ecosystems. The objective of our semi-field study was to elucidate the fate of alachlor, atrazine, chlorpyrifos, endosulfan, metolachlor, profenofos, simazine, and trifluralin in the aqueous environment of the Pantanal wetland (MT, Brazil). To this aim, water and water/sediment microcosms of two sizes (0.78 and 202 l) were installed in the outskirts of this freshwater lagoon environment and pesticide dissipation was monitored for up to 50 d after application. The physical-chemical water conditions that developed in the microcosms were reproducible among field replicates for both system sizes. Pesticide dissipation was substantially enhanced for most pesticides in small microcosms relative to the large ones (reduced DT(50) by a factor of up to 5.3). The presence of sediment in microcosms led to increased persistence of chlorpyrifos, endosulfan, and trifluralin in the test systems, while for polar pesticides (alachlor, atrazine, metolachlor, profenofos, and simazine) a lesser persistence was observed. Atrazine, simazine, metolachlor, and alachlor were identified as the most persistent pesticides in large water microcosms (DT(50) > or = 47 d); in large water/sediment systems endosulfan beta, atrazine, metolachlor, and simazine showed the slowest dissipation (DT(50) > or = 44 d). A medium-term accumulation in the sediment of tropical ecosystems can be expected for chlorpyrifos and endosulfan isomers (11-35% of applied amount still extractable at 50 d after application). We conclude that the persistence of the studied pesticides in aquatic ecosystems of the tropics is not substantially lower than during summer in temperate regions.
KW  - Brazil
KW  - Geologic Sediments: analysis
KW  - Pesticides: analysis
KW  - Pesticides: metabolism
KW  - Tropical Climate
KW  - Water Microbiology
KW  - Water Pollutants, Chemical: analysis
KW  - Water Pollutants, Chemical: metabolism
KW  - Wetlands
KW  - Pesticides (NLM Chemicals)
KW  - Water Pollutants, Chemical (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:17166548
UR  - <Go to ISI:>//WOS:000245397100017
DO  - DOI:10.1016/j.chemosphere.2006.10.067
UR  - https://juser.fz-juelich.de/record/57152
ER  -