Pesticides migration

The powder-producing collar contains a solid solution of the drug in the resin. Shortly after the collar is processed, the particles or molecules of the pesticide migrate from within the body of the resin and form a coating of particles, known as bloom, resembling a dust or powder on the collar surface. 

King PH, McCarty PL. 1968. A chromatographic model for predicting pesticide migration in soils. 

Klaine, S.J., M.L. Hinman, D.A. Winkelmann, K.R. Sauser, J.R. Martin, and L.W. Moore (1988). Characterization of agricultural nonpoint pollution Pesticide migration in a west Tennessee watershed. Environ. Toxicol. Chem., 1 609-614. 

King, P.H., McCarthy, P.L. (1968) A chromatographic model for predicting pesticide migration in soils. Soil Sci. Soc. Am. Proc. 106, 248-261. 

Study of Pesticide Migration in the Unsaturated and Saturated Zones of Dougherty Plain, Southwest Georgia... 

Collection of Soil and Water Samples. Soil sampling provides information on unsaturated zone pesticide migration, and as such, is the most critical data that will come out of a prospective field study. For this reason, soil sampling programs should adequately describe pesticide fate horizontally, vertically, and temporally (over time). 

During the dry season, the formation of soil cracks, macro- and micropores is common in the Asian countries with monsoon climate. This process is especially important in irrigation fields where water fluxes will stimulate the pesticide migration downward in the soil profile. 

Controlled amounts of pesticide migrate from reservoir layer to surface... 

Pests and Insecticides. The most destmctive pests of the cotton plant are the boU weevil and the boUworm/budworm complex. They are serious threats to the cotton industry in countries around the world. The boU weevil migrated from Mexico around 1892 and spread over the entire cotton belt within 30 years. The domestic cotton crop lost to the weevil is worth 200 million a year. In addition, about 75 million a year is spent for pesticides to control this destmctive pest (8). Unfortunately, some insecticides used to control the weevil kill many beneficial insects. Among the undesired casualties are insects that help to control the boUworm and the tobacco budworm, pests that cause another 200 million loss in cotton. 

Figure 6.13 SEE-MEKC electropherogram of the pesticide carbaryl in a tomato sample the peak assigned number (4) coiresponds to the migration time of carbaryl. (from ref. 58).

As concluded by Menzinger et CE will only fully augment chromatographic techniques in the routine determination of pesticide residues when software becomes capable of compensating for the intrinsic variability in analyte migration times. This... 

Ticks and fleas tend to concentrate in or migrate through the neck area of the animal. As they do this, they contact the active pesticide on or released by the collar and are killed. Powder-producing collars have an advantage over vaporous ones in that by the movement of the dog or cat, the powder crystals (bloom) are rubbed or wiped onto the fur, which expands the contact area allowing it to continue to control the ticks and fleas [20]. 

To which phase is the substance likely to migrate will a pesticide applied to soil leach or be volatile will a chemical accumulate in the biotic compartment and so on. 

At the fundamental level of equilibrium modeling the advantages are many. The model can combine a number of compartments through simple relationship to describe a realistic environment within which chemicals can be ranked and compared. Primary compartments that chemicals will tend to migrate toward or accumulate in can be identified. The arrangement of compartments and their volumes can be selected to address specific environmental scenarios. Data requirements are minimal, if the water solubility and vapor pressure of a chemical are known, other properties can be estimated, and a reasonable estimate of partitioning characteristics can be made. This is an invaluable tool in the early evaluation of chemical, whether the model be applied to projected environmental hazard or evaluation of the behavior of a chemical in an environmental application, as with pesticides. Finally, the approach is mathematically very simple and can be handled on simple computing devices. 

Onishi, Y., S.M. Brown, A.R. Olsen, M.A. Parkhurst, S.E. Wise and W.H. Walters. Methodology for Overland and Instream Migration and Risk Assessment of Pesticides. Batelle Pacific NW Labs., Richland, WA. Prepared for U.S. EPA, Athens, GA. 1979. 

This high agriculture activity compromises the chemical and ecological status of the Ebro delta. Pesticides used in the area migrate into the delta building up, together with the pollution produced by some industries, a contamination that can be dangerous to its both fauna and flora, and this contamination increases when water from the rice fields is drained into the delta [17]. 

Komarovskii, F.Ya., Maslova, O. V., Pishcholka, Iu. K., Shebunina, N. A. (1981). Accumulation and migration of persistent pesticides under slow discharge conditions (river delta-reservoir). Chemistry in Agriculture, 10, 45-47. 

Lunev, M. I. (1989). Models of pesticide transformation in realization of monitoring of soils and plants. In Migration of Pollutants in Soil and Other Compartments of the Environment. Obninsk. Gidrometeoizdat, pp. 38 14. 

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