Leafeair transfer of organochlorine pesticides from three selected vegetables Xinglun Yang, Xin Jiang * , Guifen Yu, Fenxia Yao, Yongrong Bian, Fang Wang State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 East Beijing Road, Nanjing 210008, China Received 6 July 2006; received in revised form 14 November 2006; accepted 25 November 2006 The leafeair transfer of OCPs varied significantly among chemicals and the three selected vegetables. Abstract The leafeair transfer of organochlorine pesticides (OCPs) in three kinds of vegetables, namely lettuce, romaine and garlic leaves was investigated. It was found that although the uptake of OCPs by the three selected vegetables was similar under controlled conditions, the depuration varied significantly among chemicals and plant species in terms of elimination rate, final residue of each OCPs, as well as the effect of temperature on the residue of OCPs in the vegetables. The results indicated that neither QCB nor HCB could be trapped tightly by any of the three selected vegetables, in contrast, p,p 0 -DDT could be retained effectively by all of them; the retainment of a-HCH, g-HCH, p,p 0 -DDE, was dependent on the vegetable species, of which the garlic leaf had the biggest ability to trap them. Our work provided insight into the behavior of OCPs in the agroecosystem. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Leafeair transfer; Vegetable; Organochlorine pesticide; SOCs 1. Introduction The airevegetation exchange of semivolatile organic com- pounds (SOCs) such as organochlorine pesticides (OCPs) plays an important role in influencing atmospheric concentra- tions, environmental persistence, regional/global cycling and human exposure (Simonich and Hites, 1994, 1995). Previous studies indicated the differences in the airevege- tation exchange of SOCs (Komp and McLachlan, 1997b; Lead et al., 1996; Ockenden et al., 1998; Smith et al., 2001; Wagrowski and Hites, 1997). There are three main factors that would result in the differences. Detailedly, the first is the physicochemical properties of compound, of which octanole air partition coefficient (K OA ) is the most important because it controls the atmospheric deposit mechanisms (i.e., dry gaseous deposition, dry particulate deposition, wet deposition) (Welsch-Pausch et al., 1995). A framework developed by McLachlan (1999) suggested that the uptake behavior of compounds with log K OA  9 was determined by equilibrium partitioning; for 9 < log K OA < 11 kinetically limited gaseous deposition dominated, and for log K OA  11 particle-bound deposition was most important. The second is the properties of vegetation. Variations between plants in surface morphol- ogy, lipid content, composition and permeability of the cutic- ular skin might profoundly influence the airevegetation exchange. Komp and McLachlan (1997a) found that PCB concentration varied significantly among the five different grasses. Bohme et al. (1999) found that the concentration of compound with log K OA less than eight varied by a factor of about 30 among the 10 agricultural plants. Ockenden et al. (1998) suggested that it was necessary to collect samples of the same species when vegetation pollutant burdens were * Corresponding author. Tel./fax: þ86 25 86881195. E-mail address: jiangxin@issas.ac.cn (X. Jiang). 0269-7491/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.envpol.2006.11.029 Environmental Pollution 148 (2007) 555e561 www.elsevier.com/locate/envpol