Model approach for estimating potato pesticide bioconcentration factor

Abstract

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.

New concepts for dynamic plant uptake models

“…for the aerial plant part [7] and for root uptake and translocation to stem and fruits [12,[16][17], but these are limited to constant conditions (i.e. one period).…”

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]). In most cases, the underlying different equations have been solved for steady-state and/or numerically for dynamic studies.…”

Organochlorine (chlordecone) uptake by root vegetables

“…Moreover, tubers are not directly connected to the root system or to the transpiration stream but are loaded via the phloem from leaves, which is assumed to be free of CLD. The concentration of lipophilic compounds in thick roots and tubers is thus limited by dilution due to growth through filling processes (Trapp, 2002;Trapp et al, 2007;Paraíba and Kataguiri, 2008).…”

Estimation of herbicide bioconcentration in sugarcane (Saccharum officinarum L.)

“…In case of plants for food, the BCF permits scientists to evaluate the human's daily ingestion of pesticide establishing safe limits for concentration in the medium (PARAIBA & KATAGUIRI, 2008). This research used this model to estimate sugarcane herbicide absorption from soil solution.…”

“…Several models simulate any substance uptake by plants (TRAPP & MATTHIES, 1995;FUJISAWA et al, 2002;TRAPP et al, 2003;TRAPP, 2007;PARAIBA & KATAGUIRI, 2008). Some researchers developed models to simulate specific substance uptake by leaves (TRAPP, 1995), roots and tubers, (TRAPP et al, 2003;PARAIBA & KATAGUIRI, 2008) or by roots and leaves (FUJISAWA et al, 2002;TRAPP, 2007). However, none of these models estimate the herbicide bioconcentration factor and uptake in sugarcane.…”