Pesticides surfactant impact

As in the other universities, the holistic principle constitutes the base of chemistry education in Southwest State University (SSU) situated in Kursk. The environmental issues as well as green chemistry are involved in teaching courses of nearly all chemistry disciplines provided hy the Department of Chemistry of SSU (Head, Associate Prof. O.V. Burykina). During the course of inorganic chemistry attention is paid to the impact of chemicals (sulfur dioxide, carbon monoxide, ions of heavy metals, pesticides, surfactants) on vital functions of living organisms. 

Surfactants that impact the dynamic surface tension of the pesticide can impact spray drift Generally, these are included within the formulation rather than tank mixed at application. 

Bioaccumulation All classes of surfactant are active surface tension depressants. At the critical micelle concentration (CMC) abrupt changes occur in the characteristic properties of surfactants such that surface and interfacial tensions in an aqueous system are at their minimum while osmotic pressure and surface detergent properties are significantly increased. The CMC for most surfactants is reached around 0.01% (18, 19). These effects have an impact on the potential for bioaccumulation of the pesticide, and in the organisms monitored the presence of Dowanol and nonylphenol increased the accumulation of fenitrothion and aminocarb at least 20-300% respectively, over the accumulation obtained in their absence (20). In effect, these adjuvants... 

The basis and likely impact of this Directive have been described. Apart from some very brief comments, there has been no specific reference to surfactants. This is because the Directive covers any chemical that falls within the scope as described and whilst this will include many surfactants, it also includes many other types. Having said this, there is no reason to suppose that surfactants will fare better than any other class of chemicals. Also, as indicated at the beginning, this chapter describes the situation in autumn 2004 when much of the impact due to the transitional measures is still to be realised. This Directive is considered by many to be over the top control for this group of products. However, this is an inevitable consequence of biocidal products also being known as pesticides. Only time will tell whether this Directive will actually improve or increase the levels of risk to humans, animals or the environment. 

Surfactants have significant impact on the application of pesticides beyond the effects in the formulation. Since the formulations are generally diluted, the surfactants must function well in the dilution process, with rapid dispersion into the diluting liquid, which is usually water. During the application process, the diluted product must be applied to the desired area with minimal drift or movement off the target site. The droplets of spray should hit the target and stay on the surface as... 

Oils, such as crop oil and crop oil concentrates, or solvents such as Al-alkyl pyrrolidones, can have a significant impact on pesticide nptake. The oils can aid in solubilizing the leaf cuticle as an aid to penetration, and also aid the solnbilization of the AI and distribution into plant leaf waxes. The polar alkyl pyrrolidone-based solvents often act as solvents for the pesticide, thus aiding leaf penetration as do the paraffinic and vegetable oils and the methylated seed oils. Mixtures of these solvents with surfactants and vinylpyrroUdone copolymers can act as wetters, stickers, and penetration-enhancers, increasing the rate of penetration of the pesticide as well as limiting wash off of the pesticide by dew or rain [38]. 

Degradation and metabolism are the means by which pesticides are removed from the environment. Metabolism of the pesticide is often enhanced by rapid uptake by the target organism and completion of biochemical pathways. The various surfactants in the formulation or adjuvants that are tank mixed to promote uptake can have a significant impact on metabolism. Aids to translocation to the active site or areas of degradation will also have an impact on metabolism of the AI. 

Impacts of Surfactant Adjuvants on Pesticide Availability and Transport in Soils... 

In all the above examples, there is no question about the bio-based origin of the surfactant, its biocompatibility and its ability to quickly biodegrade. However, all these attributes are necessary but not sufficient to answer the question of sustainability. Currently there are questions being raised about the sustainability of growing crops of palm oil in southeast Asia which are currently used as feedstock for soaps and other biobased surfactants. Some of the issues being considered are reduction in biodiversity, deforestation, impact of fertilizers and pesticides, and reduction in the natural habitat for numerous species [1], With respect to the production of biosurfactants by microorganisms (e.g. rhanmoUpids and sophorolipids), valuable carbon sources such as glucose are often used. These carbon sources are expensive, and are also a food source for animals and humans. 

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