Atrazine and Its Primary Metabolites in Swiss Lakes: Input Characteristics and Long-Term Behavior in the Water Column

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• 作者：Stephan R. Mü ; ller ; Michael Berg ; Markus M. Ulrich ; and René ; P. Schwarzenbach
• 刊名：Environmental Science & Technology
• 出版年：1997
• 出版时间：July 1997
• 年：1997
• 卷：31
• 期：7
• 页码：2104 - 2113
• 全文大小：425K
• 年卷期：v.31,no.7(July 1997)
• ISSN：1520-5851

文摘

In order to assess the impact of herbicides on aquaticecosystems, detailed information on the factors thatgovernthe input and the behavior of such chemicals in rivers,lakes, and coastal seawater is required. In this context,westudied the input characteristics (seasonal variation) aswell as the distribution and residence time of theherbicidesatrazine, simazine, and terbutylazine and of the primaryatrazine metabolites hydroxyatrazine, desethylatrazine,anddeisopropylatrazine in three Swiss lakes exhibiting quitedifferent catchment areas and/or hydraulic properties.Theresults obtained from numerous field measurements (periodof 5 years, 1990-1994) combined with computersimulations indicate that all compounds investigatedshoweda conservative behavior in the water column of the lakes(i.e., no elimination other than by flushing), except forashort period in the summer, where some minor eliminationoccurred in the epilimnion. The major input of boththeparent triazine herbicides and the metabolites occurred inthe epilimnion during or right after the applicationperiod.For atrazine, the most abundant of the threeherbicidesinvestigated, it is shown that the total annual inputdependedstrongly on the rainfall during the application period. Foragiven lake, the annual input varied between 0.5% (dryweather) and 2% (very wet weather) of the total amountapplied in the catchment area. For different lakesreceiving similar amounts of rainfall, very similar inputfractionswere found despite the significantly different catchmentareas. Among the metabolites, desethylatrazine occurredatlevels similar to those for atrazine, whilehydroxyatrazineand deisopropylatrazine were present at 2-4 times lowerlevels. Note that this study provides the firstquantitativedata on the transport of hydroxyatrazine from soils tosurfacewaters. The results of this study form an importantbasefor assessing or predicting past, present, and futureinputs of triazines to lakes for which only limited dataareavailable. Finally, this study demonstrates that smalllakesexhibiting a well-characterized catchment area representexcellent experimental field systems forevaluatingquantitatively the transport characteristics of herbicidesand their metabolites from soils to surface waters and forassessing the persistence of such compounds in surfacewaters.