Pesticides quantification study

The lymphocytes from 31 patients exposed to various organophosphate pesticides were examined for chromosomal aberrations (Van Bao et al. 1974). Five of the patients were exposed to methyl parathion only. Blood samples were taken 3-6 days after exposure and again at 30 and 180 days. A significant (p<0.05) increase was noted in the frequency of stable chromosomal aberrations in acutely intoxicated persons (although such cells are eventually lost from the cell population). Two of the methyl parathion-exposed persons had taken large doses orally in suicide attempts. The study limitations include small sample size, absence of a control group, lack of quantification of exposure levels, and possible... 

Agarwal et al. 1978), the quantification of these specific enzymes may indicate that exposure to endosulfan has occurred. Blood tests, such as decay curves for aminopyrine in plasma, which are semiquantitative indices of liver enzyme induction, have been used successfully in the past to demonstrate enzyme induction in pesticide-exposed workers. Because numerous chemicals found at hazardous waste sites also induce these hepatic enzymes, these measurements are not specific for endosulfan exposure. However, measurements of enzyme activity, together with the detection of the parent compound or its metabolites in tissue or excreta, can be useful indicators of exposure. All of these potential biomarkers require further verification in epidemiological studies. Further studies with focus on the development of methods to separate and measure the estrogenicity of endosulfan in in vitro assays would be valuable since these assays are more sensitive and discriminative than other conventional biomarkers. Preliminary results have been presented by Sonnenschein et al. (1995). 

In this study, the preliminary findings showed that the HPLC/fluorescence data were in agreement for all 12 carbamates with HPLC/ESI-MS/MS for most of the nine fruits and vegetables at the 1.0 ng g fortification level. The recoveries were generally within 70-120% however, at the 1.0 ng g level in each commodity, HPLC/ESI-MS (single-stage MS) had difficulty with interferences for three out of the 12 carbamate pesticides (aldicarb sulfoxide, aldicarb sulfone, and 3-hydroxycarbofuran), which made quantification impossible for these three compounds. 

These different considerations have led us to assume that this method would be useful to investigate the behavioral effects of toxicants in preference to more natural approaches such as studies in field or semi-field conditions because it allows better control of treatment and conditioning parameters. Indeed, precise quantification of behavior is essential for determining whether a specific non-environmental variable affects the normal behavior. The sublethal effects of chemical pesticides have already been studied using restrained workers in the CPE assay [32-35]. It remains to establish whether the use of the CPE response as a measure of the sub-lethal effects of chemicals on honey bees can be a reliable indicator of the hazards associated with the exposure to sublethal doses of toxic compounds, and consequently can be included in standard screening proce-... 

A significant peak broadening during the on-line extraction of pesticides with a hypercrosslinked polystyrene sorbent (SDB-1, J.T. Baker), followed by their HPLC separation and quantification on a C-18 analytical column was reported [248]. The problem was solved by replacing the siHca-based separating medium with PGC. This on-line combination provided trace determination of most polar pesticides such as clopyralid, methomyl, DIA, and picloram with detection limits at the low 0.1 Xg/L level for lOOmL drinking water samples. The study shows that the hypercrosslinked sorbent retains the pesticides much better than the PLRP-S resin. 

Assessment of worker exposure to pesticides through field studies requires collection devices placed on or near the worker, extraction techniques, quantification of the chemical, and statistical analysis. We present an overview of these methods with specific attention given to dermal absorption pads, their proper placement at various body locations, and the statistical variability in pad contamination which commonly results. Use of personal air samplers is reviewed. 

Finally, even if most of the pesticides worldwide are used in fruit and vegetable crops, data on pesticide residues in animal products are also essential, taking into account that livestock can be easily exposed to pesticides directly or through residues in their feed. For instance, the 2009 European Union Report revealed the presence of 34 different pesticides in animal products [115]. Garcfa de Llasera et al. [128] revealed the presence of chlofenvinphos and chlorpyrifos in liver samples, whereas a-endosnlfan, endosulfan sulfate, and dichloran have been reported in pork and lamb samples (<10 pg/kg) [129]. Bolafios et al. [130] studied the occurrence of organochlorine pesticides and polychlorinated biphenyls in chicken eggs. Benzene hexachloride and 28 polychlorinated biphenyl were detected in only one of the 30 samples at concentrations of 15 and 10 ng/g, respectively. However, five samples also contained traces of OC and PCB residues, even if at concentration levels below the limit of quantification. Einally, a-endosulfan and P-endosulfan were found in commercial milk-based infant formulas at concentration levels from 1.18 to 5.03 pg/kg [35]. The same study also showed the presence of fenitrothion, chlorpyrifos ethyl, and bifenthrin at maximum concentrations of 0.23,1.30, and 0.68 pg/kg, respectively. 

Despite the usefulness of exposure models to estimate exposure of population in different scenarios, the necessity of quantitative exposure data either for registration or for epidemiological studies, is widely recognised [19]. The quantification of the exposure is a critical issue and can be addressed from many different points of view. It is not always easy to select the correct strategy. Biomarkers for monitoring pesticides, among other chemicals. 

Pedrosa VA, Codognoto L, Machado SAS et al (2004) Is the boron-doped diamond electrode a suitable substitute for mercury in pesticide analyses A comparative study of 4-nitrophenol quantification in pure and natural waters. J Electroanal Chcan 573 11-18... 

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