« Previous AbstractEnvironmentally benign formation of polymeric microspheres by rapid expansion of supercritical carbon dioxide solution with a nonsolvent    Next AbstractInfluence of pesticide concentration on their heterogeneous atmospheric degradation by ozone »

Sci Total Environ

Title:		Heterogeneous degradation of pesticides by OH radicals in the atmosphere: Influence of humidity and particle type on the kinetics
Author(s):		Mattei C; Wortham H; Quivet E;
Address:		"Aix Marseille Univ, CNRS, LCE, Marseille, France; French Environment and Energy Management Agency, 20, avenue du Gresille, BP 90406, 49004 Angers Cedex 01, France. Aix Marseille Univ, CNRS, LCE, Marseille, France. Aix Marseille Univ, CNRS, LCE, Marseille, France. Electronic address: etienne.quivet@univ-amu.fr"
Journal Title:		Sci Total Environ
Year:		2019
Volume:		20190207
Issue:
Page Number:		1084 - 1094
DOI:		10.1016/j.scitotenv.2019.02.038
ISSN/ISBN:		1879-1026 (Electronic) 0048-9697 (Linking)
Abstract:		"Pesticides can be adsorbed on the surface of atmospheric aerosol, depending on their physicochemical properties. They can be degraded by atmospheric oxidants such as OH radicals but the influence of some environmental parameters on the degradation kinetics, especially relative humidity and particle surface type, is not well understood. Heterogeneous degradation by OH radicals of eight commonly used pesticides (i.e., difenoconazole, tetraconazole, cyprodinil, fipronil, oxadiazon, pendimethalin, deltamethrin, and permethrin) adsorbed on hydrophobic and hydrophilic silicas at a relative humidity ranging from 0% to 70% was studied. Under experimental conditions, only cyprodinil, deltamethrin, permethrin, and pendimethalin were degraded by OH radical in atmospheric relevant concentration. Second-order kinetic constants calculated for the pesticides degraded by OH radicals ranged from (1.93?ª++/-?ª+0.61)?ª+x?ª+10(-13)?ª+cm(3)?ª+molecule(-1)?ª+s(-1) (permethrin, hydrophobic silica, 30% RH) to (4.08?ª++/-?ª+0.27)?ª+x?ª+10(-12)?ª+cm(3)?ª+molecule(-1)?ª+s(-1) (pendimethalin, hydrophilic silica, 0% RH). Results obtained can contribute to improve the understanding of the atmospheric fate of pesticides and other semi-volatile organic compounds in the particulate phase and they highlight the importance of taking humidity and particle type into account for the determination of pesticides atmospheric half-lives"
Keywords:		Aerosols Atmosphere Degradation Humidity OH radical Pesticides;
Notes:		"PubMed-not-MEDLINEMattei, Coraline Wortham, Henri Quivet, Etienne eng Netherlands 2019/03/25 Sci Total Environ. 2019 May 10; 664:1084-1094. doi: 10.1016/j.scitotenv.2019.02.038. Epub 2019 Feb 7"