Paraíba Lourival Costa, Kataguiri Karen
Embrapa Meio Ambiente, Embrapa Environment, CxP. 69, CEP 13820-000, Jaguariúna, São Paulo, Brazil.
Chemosphere. 2008 Nov;73(8):1247-52. doi: 10.1016/j.chemosphere.2008.07.026. Epub 2008 Aug 26.
We presented a model that estimates the bioconcentration factor (BCF) of pesticides in potatoes supposing that the pesticide in the soil solution is absorbed by the potato by passive diffusion, following Fick's second law. The pesticides in the model are nonionic organic substances, traditionally used in potato crops that degrade in the soil according to a first-order kinetic equation. This presents an expression that relates BCF with the pesticide elimination rate by the potato, with the pesticide accumulation rate within the potato, with the rate of growth of the potato and with the pesticide degradation rate in the soil. BCF was estimated supposing steady state equilibrium of the quotient between the pesticide concentration in the potato and the pesticide concentration in the soil solution. It is suggested that a negative correlation exists between the pesticide BCF and the soil sorption partition coefficient. The model was built based on the work of Trapp et al. [Trapp, S., Cammarano, A., Capri, E., Reichenberg, F., Mayer, P., 2007. Diffusion of PAH in potato and carrot slices and application for a potato model. Environ. Sci. Technol. 41 (9), 3103-3108], in which an expression to calculate the diffusivity of persistent organic substances in potatoes is presented. The model consists in adding to the expression of Trapp et al. [Trapp, S., Cammarano, A., Capri, E., Reichenberg, F., Mayer, P., 2007. Diffusion of PAH in potato and carrot slices and application for a potato model. Environ. Sci. Technol. 41 (9), 3103-3108] the hypothesis that the pesticide degrades in the soil. The value of BCF suggests which pesticides should be monitored in potatoes.
我们提出了一个模型，该模型假定土壤溶液中的农药通过被动扩散被马铃薯吸收，遵循菲克第二定律，来估算马铃薯中农药的生物富集系数（BCF）。模型中的农药为非离子有机物质，是传统上用于马铃薯作物的，会根据一级动力学方程在土壤中降解。该模型给出了一个表达式，将BCF与马铃薯对农药的消除率、农药在马铃薯内的积累率、马铃薯的生长速率以及农药在土壤中的降解率联系起来。BCF是在假定马铃薯中农药浓度与土壤溶液中农药浓度的商处于稳态平衡的情况下估算的。研究表明，农药的BCF与土壤吸附分配系数之间存在负相关关系。该模型是基于特拉普等人的研究成果构建的[特拉普，S.，卡马拉诺，A.，卡普里，E.，赖兴贝格，F.，迈尔，P.，2007年。多环芳烃在马铃薯和胡萝卜切片中的扩散及其在马铃薯模型中的应用。《环境科学与技术》41（9），3103 - 3108]，其中给出了一个计算持久性有机物质在马铃薯中扩散率的表达式。该模型是在特拉普等人的表达式基础上[特拉普，S.，卡马拉诺，A.，卡普里，E.，赖兴贝格，F.，迈尔，P.，2007年。多环芳烃在马铃薯和胡萝卜切片中的扩散及其在马铃薯模型中的应用。《环境科学与技术》41（9），3103 - 3108]，加入了农药在土壤中会降解这一假设。BCF的值表明了哪些农药应该在马铃薯中进行监测。
