Pesticide Volatilization from Plants: Improvement of the PEC Model PELMO Based on a Boundary-Layer Concept

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• 作者：André ; Wolters ; Minze Leistra ; Volker Linnemann ; Michael Klein ; Andreas Schä ; ffer ; and Harry Vereecken
• 刊名：Environmental Science & Technology
• 出版年：2004
• 出版时间：May 15, 2004
• 年：2004
• 卷：38
• 期：10
• 页码：2885 - 2893
• 全文大小：372K
• 年卷期：v.38,no.10(May 15, 2004)
• ISSN：1520-5851

文摘

Calculation of pesticide volatilization from plants as anintegral component of pesticide fate models is of utmostimportance, especially as part of PEC (predicted environmentalconcentrations) models used in the registration proceduresfor pesticides. A mechanistic approach using a laminar air-boundary layer concept to predict volatilization from plantsurfaces was compared to data obtained in a wind-tunnel study after simultaneous application of parathion-methyl, fenpropimorph, and quinoxyfen to winter wheat.Parathion-methyl was shown to have the highest volatilizationduring the wind-tunnel study of 10 days (29.2%). Volatilizationof quinoxyfen was about 15.0%, revealing a highervolatilization tendency than fenpropimorph (6.0%), whichis attributed to enhanced penetration of fenpropimorphcounteracting volatilization. Predictions of the boundary-layer approach were markedly influenced by the selectedvalues for the equivalent thickness of the boundarylayer and rate coefficients, thus indicating that futureimprovements of the approach will require a deeperunderstanding of the kinetics of the underlying processes,e.g. phototransformation and penetration. The boundary-layer volatilization module was included in the Europeanregistration model PELMO, enabling simultaneouscalculation of volatilization from plants and soil. Applicationof PELMO to experimental findings were the firstcomprehensive PEC model calculations to imply therelevant processes affecting the postapplication fate ofpesticides.