Reduction of pesticides

Table 4-9 Reduction of pesticide Input In different farming systems ...

Tabie 4-9 Reduction of pesticide input in different farming systems 51... 

Processes of such kinds can be found in the literature. E. Stahl, et al. [1] describe the decontamination of drugs, in particular, the reduction of pesticides from senna leaves by means of supercritical dry carbon dioxide [2]. The patents EP 0382116 A2 [4] and DE 4342874 Al [5] specify processes to remove non-polar substances from ginseng with dense carbon dioxide, in which the ginseng is moisturized prior to extraction, and the second method also uses an entrainer. The European Patent Application EP 0925724 A2 from NATEX [3] explains a process for the removal of plant-protection agents and/or undesired substances from cereals. 

But what about the dramatic reductions of pesticide use in China after the farmers started using genetically engineered Bt cotton I ask, Aren t you pleased that GE has helped reduce the use of pesticides ... 

The effect of rice cleaning and cooking on the residues of silafluofen (37) was described in rice that had been sprayed in a paddy field with this pesticide [95]. Silafluofen was found to remain in the hull of the rice. The residual concentration of the pesticide in polished rice was higher than that in pre-washed rice processed ready for cooking. During the cooking procedure, the reduction of pesticides in polished rice was higher than that in brown rice. 

With the development of sustainable development indicators also moving into the role of pesticides and their impact on the environment, clearly, sound statistical information was required, particularly if the role of policy changes on pesticide use was to be assessed over time. Furthermore, an important target of the European Union s (EU) 5th Environmental Action Programme was the reduction of pesticide risk, but this would be impossible to monitor without sound information on changes in use over time. 

Davies, J. E., Edmundson, W. F., Maceo, A., Irvin, G. L. Cassady, J. and A. Barquet. 1971. Reduction of pesticide residues in human adipose tissue with diphenylhydantoin. Eood Cos-met. Toxicol, 9 413-23. 

Most of the technological processes used in fruit and vegetable processing include washing and blanching. The decrease in the levels of pesticide residues is possible particularly in the case of pesticides that are soluble in water, or in the case of contact pesticides deposited on the plant surface that can be mechanically removed. The overall effects resulting in a reduction of pesticide residues depend on a number of factors, the most important of which are ... 

One of the leading cork producers, Sabate, began the development of a cork cleaning process with supercritical gases in 1997 [32, 33]. The tests were very successful and, consequently, the process was patented. With supercritical gas, it was possible to reduce the TCA content below the detectable limit, which is at the moment around 0.2 ng/1. Furthermore, CO2 has special properties regarding reduction of pesticides and inhibition of fungus growth. 

Naphthalenesulfonic acid can be converted to l-naphthalenethiol/T25 -J6 - by reduction of the related sulfonyl chloride this product has some utihty as a dye intermediate, and is converted by reaction with alkyl isocyanates to 3 -naphthyl-A/-alkylthiocarbamates, which have pesticidal and herbicidal... 

Reduction of Nitro Substituents. These reactions are very common in anaerobic environments and result in amine-substituted pesticides anaerobic bacteria capable of reducing nitrate to ammonia appear to be primarily responsible. All nitro-substituted pesticides appear to be susceptible to this transformation, eg, methyl parathion (7) (eq. 9), triduralin, and pendimethalin. 

Reductive DechIorina.tion. Such reduction of chlorinated aUphatic hydrocarbons, eg, lindane, has been known since the 1960s. More recentiy, the dechlorination of aromatic pesticides, eg, 2,4,5-T, or pesticide products, eg, chlorophenols, has also been documented (eq. 10) (20). These reactions are of particular interest because chlorinated compounds are generally persistent under aerobic conditions. 

In addition, the DoE proposed EQSs in a 1991 consultation document for those pesticides on the Red List (the UK s original priority hazardous substances list). Although non-statutory, the Government is committed to the reduction of Red List Substances discharging to the North Sea and the NRA uses the standards to assess the effects of these substances on the environment and to derive consents for point source discharges of these compounds. Failures for agricultural pesticides are rare. 

Coiieotion of pesticide onto poiyurethane foam using high voiume sampier extraotion of PUF using 5% ether in hexane extraot voiume reduction ooiumn oiean-up... 

Some Factors to Consider in Reduction of N-Nitroso Compounds in Pesticides... 

Chemically, nitrosamines are considered to be quite stable compounds and are difficult to destroy cmce they are formed. Reducing or destroying preformed nitrosamines in pesticides offers special challenge, as they occur in trace amounts which require specific selective treatment without effecting the composition of the principal product. Experimental laboratory work revealed that reactions suitable for mass quantities of reactants, that is neat samples, are not necessarily analagous to micro reactions for the reduction of a given trace nitrosamine contaminant or impurity. 

Before the EPA proceeds on a regulatory action, registrants whose products exceed the 10 risk level from nitroso contamination, will be given the opport mity to lower potential exposure to applicators and other users of their pesticides. Reduction of exposure and, thus, reduction of risk can be accomplished by modification of the manufacturing process (see below), improved packaging technology, modification of application technique (e.g. closed systems), or deletion of high-exposure uses. 

At least 26 oxidative, 7 reductive, and 14 hydrolytic transformations of pesticides had been identified. Detailed identification and discussion of specific reactions can be found in the works of Alexander56 and Scow.57... 

C) their relative adsorptivities will converge and that as the temperature increases, their relative adsorptivities will diverge as butylate becomes more strongly adsorbed and alachlor and meto-lachlor become less strongly adsorbed. This result should translate into a reduction of leaching of butylate (compared to alachlor and metolachlor) as the temperature of the soil system is raised. Thus, the effect of temperature can be handled by an environmental model for soil mobility by including the heat of adsorption of the pesticide. 

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