Pesticide studies related

Few epidemiologic studies of pesticide use in general, or specific pesticides, in relation to any autoimmune disease. Mechanistic research primarily for hexachlorobenzene and malathion. Mechanisms other than endocrine-disruption should be considered, even for pesticides with endocrine-disrupting properties. 

The p-values for over 100 pesticides and related substances were established by studying the extraction behavior of those compounds in a wide range of binary solvent systems. Gas chromatography—based on electron-capture detection—was used to obtain the experimental data. As a result of these studies, Beroza and Bowman reported that ... 

Dermal Exposure Levels. Setting acceptable maximum dermal exposure levels to specific pesticides has been difficult. This is primarily due to a lack of specific data on dermal transport rates for specific pesticides as related to adverse effect levels and presumed no-effect levels. We are now requiring such data from the registrants, and our Department has a suggested protocol (1) that is offered to registrants that will provide such information from animal exposure studies. This dermal transport rate information is important in setting minimum field reentry intervals for field workers as well as in evaluating exposure levels of mixers, loaders, and applicators. 

As Table I illustrates, the chemical classes represented by the pesticides studied include thiophosphates [0,0-diethyl-o-p-nitrophenyl phos-phorothioate], carbamates [1-naphthyI-N-methylcarbamate], dinitrophe-nols [2,4-dinitro-o-sec-butylphenol and 2,4-dinitro-o-cyclohexylphenol], and chlorophenoxy acids [2,4-dichlorophenoxyacetic acid, 2,4,5-trichloro-phenoxyacetic acid, and 2-(2,4,5-trichlorophenoxy)propionic acid]. In addition, a number of molecularly related nitrophenols have been studied to establish the effects of molecular geometry and substituent groups on adsorption of pesticide-type materials. 

LC-MS plays an important role in the analysis of pesticides and related componnds, e.g., herbicides, insecticides, acaricides, as well as their degradation prodncts and metabolites. The analysis of pesticides is relevant for environmental studies, food safety, toxicology, and occupational health. Pesticides have to be analysed in environmental samples, such as different water compartments, soil, sediments, sludge, and animal tissue like fish, in food, especially fruit and vegetables, and in (human) body fluids and tissues. Many modem pesticides and related compounds are not amenable to GC-MS analysis, or only after derivatization. Therefore, LC-MS has been evaluated as an alternative. Various review papers on the analysis of pesticides and related compounds in various sample matrices were published [1-8]. 

A second study related to Parkinson s disease involved the effects of a mixture of the herbicide paraquat and the fungicide maneb (a combination commonly applied to crops). Paraquat alone and maneb alone adversely affect dopamine systems, but the effects of the mixture are greater than that of either pesticide alone. ... 

For a good discussion of on-line SPE coupled to HPLC, the work of Hennion and Pichon (1994) and Hennion and co-workers (1990) discuss environmental applications. In their work, the styrene-divinylbenzene copolymers are used as SPE columns with good capacity for many of the environmentally relevant contaminants and allow for direct analysis by HPLC. Hennion and Pichon (1994) discuss and review a number of studies on pesticides and related compounds by on-line SPE. There is also more discussion of on-line SPE methods coupled to GC/MS in Chapter 10. 

Review of Selected Epidemiologic Studies Related to Pesticide Exposure... 

The only study located regarding immunological effects in humans after dermal exposure to endosulfan was an account of the results of patch tests on the backs of 14 farm workers with work-related dermatitis and 8 controls who were not exposed to pesticides (Schuman and Dobson 1985). Skin sensitization was not observed in any of the subjects following a 48-hour, closed-patch exposure to an unspecified amount of 0.1 % endosulfan in petrolatum. 

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