Uptake of pesticides

N. Muro-Sune, A. Munir, R. Gani, G. Bell, I. Shirley, 2005, A framework for product analysis Modelling and design of release and uptake of pesticides, in Puigjaner L, A. Espuna, European Symposium on Computer Aided Process Engineering-15, Elsevier, Amsterdam.The Netherlands. 

Behrendt, H., Bruggemann, R. (1993) Modelling the fate of organic chemicals in the soil plant environment model study of root uptake of pesticides. Chemosphere 27, 2325-2332. 

Lide, D.R., Editor (2003) Handbook of Chemistry and Physics. 84th Edition, CRC Press, LLC. Boca Raton, Florida Lohninger, H. (1994) Estimation of soil partition coefficients of pesticides from their chemical structure. Chemosphere 29(8), 1611-1626. Lord, K.A., Briggs, G.C., Nearle, M.C., Manlove, R. (1980) Uptake of pesticides from water and soil by earthworms. Pest. Sci. 11, 401 108. 

The uptake of pesticides by earthworms from soil has been modeled by Magee (1991) ... 

The study of the efficacy and behaviour of different products and their formulations has evolved through purely empirical field trials, into various controlled environment or laboratory screening methods, to more detailed fundamental and mechanistic studies, leading to the development of models for the processes of deposition, retention, uptake and translocation [3]. This overview will consider these processes, their limitations, and their future potential. Due to the fact that most studies have been with herbicides into plants, with little or no information on uptake of pesticides by insects or padiogens, the main focus will be on the uptake of herbicides into plant foliage. 

Compounds that alter insect behavior in other ways may also be useful e.g. chemicals that increase insect locomotor activity should enhance the uptake of pesticides from treated surfaces. Such compounds are already known among the formamidines insecticides and their relatives that stimulate octopamine receptors (12), and further research in this area of pest biochemistry could reveal other locomotor stimulators such as phosphodiesterase inhibitors. A... 

It is also probable that a more detailed study of the factors governing the uptake of pesticides from treated surfaces could lead to improved formulations of higher efficiency and lower concentration. From the limited data available it is clear that events on the surface of the leaf or insect and the type of formulation applied may radically affect the performance of herbicides (16) and insecticides (JI) ... 

Water-borne Administration. For water-borne administration, drugs are usually prepared in a bath in which the animals are held for a period of time before introducing fresh untreated water. It is important to ensure that the drug is completely dissolved in the well-mixed water before adding the animal. This method of exposure has not to our knowledge been used to study drug uptake by crustaceans, but has been widely used for studies of the uptake of pesticides and environmental pollutants by Crustacea 74). 

Biphasic functions with a linear ascending (slope = 0.91) and descending slope (-1.975 + 0.91 =-1.065), and a rounded apex are represented by this model. Highly hydrophobic compounds with log P values > 6 cover the apical and descending part of the curve. The uptake of chemicals from food and water has been compared and tissue concentrations are similar for water and food. Thus the uptake of pesticides from food is less critical than its uptake from water and only a fraction of the residue present in the lower level biota is transferred to the higher level of the food chain. 

Aquatic species were also found to be hyperaccumulators in wetland ecosystems (Williams, 2002). Ceratophyllum demersum is described as an arsenic accumulator (Kalbitz and Wenrich, 1998), whereas water hyacinths, Eichhornia crassipes, have been found to be effective in accumulating cadmium, lead, and mercury, and in the uptake of pesticides residues. Duckweed Lemna minor) and water velvet (Azolla pinnata) were both found to effectively remove iron and copper at low concentrations in laboratory experiments, and also cadmium. The yellow water lily (Nuphar variegatum) accumulated copper and zinc. 

Trisiloxane surfactants have been used as adjuvants in agriculture. They increase the foliar uptake of pesticides, due to reduction of surface tension and superspreading. A method for improving the performance of agricultural compositions under conditions of low humidity has been developed, by using silicone surfactants that reduce the surface tension to less than 30 mN/m in 0.10% (w/w) aqueous solution, without concomitant spreading of the spray solution [60]. 

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