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PubMed2002

Monitoring of organochlorine pesticides residues in green mussels (Perna viridis) from the coastal area of Thailand.

The utilization of organochlorine pesticides for pest control chemical has been of great interest on residue contamination from biological organisms in the environment. Green mussel (Perna viridis) samples were monitored as bioindicators for assessment of the water quality in coastal waters along the Gulf of Thailand. Thirty-six samples were collected from 12 stations during 1997-1999 and analysed for 26 organochlorine pesticide compounds. This paper focuses on the contamination of organochlorine pesticide residues in green mussel (P. viridis) during 1997-1999. The limit of detection of all organochlorine pesticides compounds was at the range of 0.1-8.3 ng g(-1) wet weight and recovery 75-95%. The concentration of organochlorine pesticides residues in green mussel was lower than the maximum residue limit for aquatic animals as recommended by the Ministry of Public Health of Thailand. The trend of organochlorine pesticide residue contamination in this area decreased from 1989 to 1999.

Animals↗
PubMed2001

Pesticide use in developing countries.

Chemical pesticides have been a boon to equatorial, developing nations in their efforts to eradicate insect-borne, endemic diseases, to produce adequate food and to protect forests, plantations and fibre (wood, cotton, clothing, etc.). Controversy exists over the global dependence on such agents, given their excessive use/misuse, their volatility, long-distance transport and eventual environmental contamination in colder climates. Many developing countries are in transitional phases with migration of the agricultural workforce to urban centres in search of better-paying jobs, leaving fewer people responsible for raising traditional foods for themselves and for the new, industrialized workforce. Capable of growing two or three crops per year, these same countries are becoming "breadbaskets" for the world, exporting nontraditional agricultural produce to regions having colder climates and shorter growing seasons, thereby earning much needed international trade credits. To attain these goals, there has been increased reliance on chemical pesticides. Many older, nonpatented, more toxic, environmentally persistent and inexpensive chemicals are used extensively in developing nations, creating serious acute health problems and local and global environmental contamination. There is growing public concern in these countries that no one is aware of the extent of pesticide residue contamination on local, fresh produce purchased daily or of potential, long-term, adverse health effects on consumers. Few developing nations have a clearly expressed "philosophy" concerning pesticides. There is a lack of rigorous legislation and regulations to control pesticides as well as training programs for personnel to inspect and monitor use and to initiate training programs for pesticide consumers.

Agriculture↗
PubMed2003

Reducing acute poisoning in developing countries--options for restricting the availability of pesticides.

Hundreds of thousands of people are dying around the world each year from the effects of the use, or misuse, of pesticides. This paper reviews the different options to reduce availability of the most hazardous chemicals, focusing on issues in developing countries. Emphasis is placed on the fatal poisoning cases and hence the focus on self-harm cases. Overall, it is argued here that restricting access to the most hazardous pesticides would be of paramount importance to reduce the number of severe acute poisoning cases and case-fatalities and would provide greater opportunities for preventive programmes to act effectively. The aim should be to achieve an almost immediate phasing out of the WHO Classes I and II pesticides through national policies and enforcement. These short-term aims will have to be supported by medium- and long-term objectives focusing on the substitution of pesticides with safe and cost-effective alternatives, possibly guided by the establishment of a Minimum Pesticide List, and the development of future agricultural practices where pesticide usage is reduced to an absolute minimum. Underlying factors that make individuals at risk for self-harm include domestic problems, alcohol or drug addiction, emotional distress, depression, physical illness, social isolation or financial hardship. These should be addressed through preventive health programmes and community development efforts.

Acute Disease↗
PubMed1999

Regulatory approaches for controlling pesticide residues in food animals.

Pesticide use is vital to the production of an economical, high-quality food supply throughout the world. The regulatory system in the United States is designed to prevent the entry of unacceptable residues into the food supply. To address the complexities associated with pesticide use, the regulatory apparatus is composed of several federal and numerous state agencies. Based on monitoring results, it appears that most pesticides are being used in the appropriate manner and that thresholds for pesticides, deemed to be adequate to protect human health, are seldom exceeded. With our increasing knowledge of the public health and ecologic threats posed by pesticide residues, our approach to regulating pesticides will continue to evolve.

Animals↗
PubMed1999

Pesticides and Parkinson's disease.

Epidemiological studies and case reports provide evidence for an association between Parkinson's disease and past exposure to pesticides. Susceptibility to the effects of pesticides and other putative neurotoxins depends on variability in xenobiotic metabolism possibly generated by genetic polymorphisms, aging and variation in exposure to environmental agents including pesticides. The simplest mechanistic hypothesis for the association of pesticides with Parkinson's disease is that pesticides or their metabolites are directly toxic to mitochondria, although modulation of xenobiotic metabolism by pesticides provides an adjunct or alternative hypothesis.

Animals↗
PubMed2002

Pesticide poisoning and depressive symptoms among farm residents.

PURPOSE: The purpose of the study presented is to evaluate the association between pesticides and depressive symptoms among a population exposed to chemicals as a result of agricultural use. Chronic sequelae of acute pesticide poisoning from organophosphate compounds may include anxiety and depression. In some states, farmers have been reported to have higher rates of depression than other population groups. Little work has been done to describe the effects of exposure to organophosphate compounds and depressive symptoms among the farming population. METHODS: Data for this study came from a cross sectional survey of farmers and their spouses conducted in an eight county area in northeastern Colorado. Personal interviews were conducted with the study participants. Depressive symptoms were assessed using the Center for Epidemiologic Studies-Depression (CES-D) scale. Pesticides applied on the farms were assessed using self-reported questionnaires. Conditional logistic regression was used to model the relationship between depression and pesticide-related illness in a stratified analysis. RESULTS: Between 1992-1997, 761 individuals were enrolled in this cross sectional survey. Adjusting for a number of potential confounders, the odds ratio for depression associated with pesticide-related illness was 5.87 [95% confidence interval (CI) = 2.56-13.44]. CONCLUSIONS: Exposure to pesticides at a high enough concentration to cause self reported poisoning symptoms was associated with high depressive symptoms independently of other known risk factors for depression among farm residents.

Adult↗
PubMed2003

The role of abiotic factors and pesticide levels on enzymatic activity in the freshwater mussel Anodonta cygnea at three different exposure sites.

Natural variation in abiotic factors, such as temperature and pH, probably influence the activity of enzymes used as potential biomarkers in bivalve mollusks to assess environmental contamination in the field. Changes in levels of an enzymatic biomarker may thus merely reflect natural variation in the annual physiological cycle of a species rather than exposure to contaminants. To investigate this issue, we documented the relationship between pesticide levels in water and three different enzymatic biomarkers over 1 year in enclosed populations of the freshwater unionid mussel Anodonta cygnea at three different sites of exposure. We considered the natural variation in temperature, pH and dissolved oxygen over the year and across the different sites as a potential correlate of enzymatic activity to disentangle the relative contribution of abiotic factors and pesticide levels. Pesticide levels varied among the three sites and over the course of the year. Catalase (CAT) and acetylcholinesterase activity (AChE) varied as a function of abiotic factors but showed no relation to pesticide levels. Glutathione S-transferase (GST) activity was also related to abiotic factors but also decreased with increases in total pesticide levels. The lack of activity induction or inhibition by pesticides and the natural variation in abiotic factors among sites and across time limits the use of CAT and AChE to assess environmental contamination in this species.

Acetylcholinesterase↗
PubMed2002

Biological monitoring of pesticide exposure: a review of analytical methods.

A wide range of studies concerned with analytical methods for biological monitoring of exposure to pesticides is reviewed. All phases of analytical procedures are assessed, including sampling and storage, sample preparation and analysis, and validation of methods. Most of the studies aimed at measuring metabolites or unchanged compounds in urine and/or blood as biological indicators of exposure or dose. Biological indicators of effect, such as cholinesterase, are also evaluated. The principal groups of pesticides are considered: organophosphorus pesticides, carbamate pesticides, organochlorine pesticides, pyrethroid pesticides, herbicides, fungicides and other compounds. Choice of the method for biological monitoring of exposure depends on the study population: a detection limit of 1 microg/l or less is required for the general population; higher values are adequate for occupationally exposed subjects. Interpretation of results is also discussed. Since biological indices of exposure are only available for a few compounds, biological reference values, established for the general population, may be used for comparison with levels of professionally exposed subjects.

Environmental Monitoring↗
PubMed2005

Quantitation and accurate mass analysis of pesticides in vegetables by LC/TOF-MS.

A quantitative method consisting of solvent extraction followed by liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS) analysis was developed for the identification and quantitation of three chloronicotinyl pesticides (imidacloprid, acetamiprid, thiacloprid) commonly used on salad vegetables. Accurate mass measurements within 3 ppm error were obtained for all the pesticides studied in various vegetable matrixes (cucumber, tomato, lettuce, pepper), which allowed an unequivocal identification of the target pesticides. Calibration curves covering 2 orders of magnitude were linear over the concentration range studied, thus showing the quantitative ability of TOF-MS as a monitoring tool for pesticides in vegetables. Matrix effects were also evaluated using matrix-matched standards showing no significant interferences between matrixes and clean extracts. Intraday reproducibility was 2-3% relative standard deviation (RSD) and interday values were 5% RSD. The precision (standard deviation) of the mass measurements was evaluated and it was less than 0.23 mDa between days. Detection limits of the chloronicotinyl insecticides in salad vegetables ranged from 0.002 to 0.01 mg/kg. These concentrations are equal to or better than the EU directives for controlled pesticides in vegetables showing that LC/TOF-MS analysis is a powerful tool for identification of pesticides in vegetables. Robustness and applicability of the method was validated for the analysis of market vegetable samples. Concentrations found in these samples were in the range of 0.02-0.17 mg/kg of vegetable.

Chromatography, Liquid↗
PubMed2005

Potentiality of gas chromatography-triple quadrupole mass spectrometry in vanguard and rearguard methods of pesticide residues in vegetables.

A new analytical strategy for the screening and confirmation/quantification of multiclass pesticide residues in vegetables has been established and validated. No complicated sample preparation was needed, but only a simple and rapid extraction using ethyl acetate and sodium sulfate, which required no cleanup. The approach is based on the use of the triple quadrupole (QqQ) mass spectrometry (MS) as detection system in gas chromatography (GC). In a first step, a GC-QqQ-MS screening method, which monitors only one MS/MS transition by compound, allows the identification of approximately 130 pesticides in 11.6 min. In this way, the differentiation between negative and potentially nonnegative samples is carried out. In the second step, the nonnegative samples are reanalyzed by the GC-QqQ-MS confirmation/quantification method, which monitors two or three MS/MS transitions by compound. Confirmation of pesticides was based on the comparison of intensity ratios for the main ions in samples with those obtained on the same day from the standard in a matrix containing the pesticides at a preestablished concentration level. Quantification of the identified and confirmed pesticides was based on the addition standard method, which avoids matrix effect. The proposed analytical strategy allowed a reliable identification and confirmation of the target pesticides at trace levels, reducing analysis time and increasing sample throughput in routine analytical laboratories.

Food Contamination↗
PubMed2005

Life- cycle assessment in pesticide product development: methods and case study on two plant-growth regulators from different product generations.

Environmental assessments in pesticide product development are generally restricted to plant uptake and emissions of active ingredients. Life-cycle assessment (LCA) enables a more comprehensive evaluation by additionally assessing the impacts of pesticide production and application (e.g. tractor operations). The use of LCA in the product development of pesticides, in addition to the methods commonly applied, is therefore advisable. In this paper a procedure for conducting LCA in early phases of product development is proposed. In a case study, two plant-growth regulators from different product generations were compared regarding their application in intensive production of winter wheat. The results showed thatthe reduced emissions from active ingredients of the newer pesticide were compensated by higher impacts from the production process. The authors draw the conclusion that it is important to consider environmental objectives in the procurement of precursors, in addition to the classical goals of increasing the efficacy and reducing the nontarget effects of pesticides. Moreover, the case study showed that decisions based on uncertain results in early stages of product development may need to be revised in later stages, e.g. based on investigations of pesticides' effects on crop yield.

Chlormequat↗
PubMed2004

Landscape-level approach to assess aquatic exposure via spray drift for pesticides: a case study in a Mediterranean area.

The development of methods to extract information from landscape analysis to refine risk assessment is becoming increasingly important. This paper presents results from a pesticide surface water exposure assessment at the watershed scale, based on a combination of edge of field studies, large-scale monitoring studies, and modeling activities with GIS-based landscape analysis methodologies covering an area of approximately 3200 ha surrounding the Simeto River in Sicily (Italy). The dynamic behavior of the pesticide chlorpyrifos-methyl was modeled in two different steps: calculation of the fraction of the application rate that is deposited beyond the field edge and simulation of the fate and persistence of the pesticide in the aquatic environment. Drift loads showed high spatial variability. Considering spray drift deposition as a fraction of the pesticide application rate, 60% of the results were < or = 0.02 (equal to 0.04 mg/m2). Only 8.5% of the results were above 0.5. The highly variability of the landscape factors was reflected in the results. More than 60% of the predicted pesticide concentrations were less than the limit of quantification (0.05 microg/L), affecting about 75% of the total length of the river tract analyzed. Predicted pesticide concentrations were higher than 0.1 microg/L in 23% of cases, but this corresponded to an insignificant portion of the river (1.2% of the total length). These results suggest that management options, such as increased no-spray zones, could provide further protection for surface water. These could be modeled to illustrate their overall impact. As an alternative, the introduction of a 20-m no-spray zone clearly reduced potential exposure, and 92% of the water body was protected. Estimated data are in agreement with data collected during a field monitoring study.

Air Movements↗
PubMed2006

Evaluation of mesoporous cyclodextrin-silica nanocomposites for the removal of pesticides from aqueous media.

The treatment of aqueous solutions containing various pesticides by cyclodextrin-functionalized mesoporous silica adsorbents was investigated. The pesticides studied belonged to three chemical structure classes: hexachlorocyclohexane-based, hexachlorobicycloheptene-based, and p,p' substituted biphenyl-based pesticides. The solutions studied contained a mass concentration with respect to each pesticide in the range of 0.060-0.270 microg/mL, values that are consistentwith the low levels typically encountered in environmental samples. Adsorbents containing low to intermediate amounts of cyclodextrin groups were found to have optimal adsorption affinity toward the pesticides. The materials were particularly specific toward p,p'substituted diphenyl-based pesticides such as DDT and DDE.

Absorption↗
PubMed2006

Temporal and spatial trends of organochlorine pesticides in Great Lakes precipitation.

Organochlorine pesticide concentrations in precipitation samples collected from 1997 to 2003 at seven Integrated Atmospheric Deposition Network sites around the Great Lakes are reported. The 28-day volume weighted mean concentrations of several pesticides, including gamma-hexachlorocyclohexane (HCH), endosulfan, hexachlorobenzene, chlordane, and DDE, showed significant seasonal trends. For current-use pesticides (endosulfan and gamma-HCH), their concentrations peaked in late spring to summer just after their agricultural application. For the banned pesticides, higher concentrations were observed in the winter due to their enhanced partitioning to particles and scavenging by snow. Long-term decreasing trends were observed for several pesticides such as gamma-HCH and DDE. On the other hand, beta-HCH showed significant increasing concentrations as a function of time at Brule River, Eagle Harbor, and Sleeping Bear Dunes. Generally, Chicago had the highest concentration of chlordanes, dieldrin, and DDT, indicating that urban areas could be a source for these compounds to precipitation. For gamma-HCH and endosulfans, Point Petre had the highest concentrations due to the application of these pesticides in the surrounding areas.

Fresh Water↗
PubMed2000

Determination of organochlorine and organophosphorus pesticide residues in eggs using a solid phase extraction cleanup.

A multiresidue solid phase extraction (SPE) method for the isolation and subsequent gas chromatographic determination of nonpolar organochlorine and polar organophosphorus pesticide residues in eggs is described. The method uses an acetonitrile extraction followed by an SPE cleanup using graphitized carbon black and aminopropyl SPE columns. Organophosphorus pesticides are determined by gas chromatography with flame photometric detection. After further cleanup of the extract using Florisil SPE columns, organochlorine pesticides are determined by gas chromatography with electron capture detection. Studies were performed using eggs containing both fortified and incurred pesticide residues. The average recoveries were 86-108% for 8 fortified organochlorine pesticide residues and 61-149% for 28 fortified organophosphorus pesticide residues.

Animals↗
PubMed2003

Determination of organophosphorus pesticides in fruit juices by matrix solid-phase dispersion and gas chromatography.

A rapid multiresidue method was developed for the determination of nine organophosphorus pesticides in fruit juices. The analytical procedure is based on the matrix solid-phase dispersion (MSPD) of juice samples on Florisil in small glass columns and subsequent extraction with ethyl acetate assisted by sonication. Residue levels were determined by gas chromatography with nitrogen-phosphorus detection. Spiked blank samples were used as standards to counteract the matrix effect observed in the chromatographic determination. The NPD response for all pesticides was linear in the concentration range studied with determination coefficients >0.999. Average recoveries obtained for all of the pesticides in the different juices and fortification levels were >70% with relative standard deviations of <11%. The detection limits ranged from 0.1 to 0.6 microg/kg. The identity of the pesticides was confirmed by gas chromatography with mass spectrometric detection using selected ion monitoring. The proposed MSPD method was applied to determine pesticide residue levels in fruit juices sold in Spanish supermarkets. At least one pesticide was found in most of the samples, although the levels detected were very low, far from the maximum residue levels established for raw fruit.

Beverages↗
PubMed2005

Wet deposition of current use pesticides at a rural location on the Delmarva Peninsula: impact of rainfall patterns and agricultural activity.

Event-based precipitation samples were collected during the main agricultural season (April-September) over 4 years (2000-2003) at one site in the Choptank River Watershed on the Delmarva Peninsula. The samples were analyzed for 19 agricultural pesticides to determine the contribution of wet deposition as a source of these compounds to the Chesapeake Bay and the factors affecting the temporal trends in deposition. Chlorothalonil was detected most frequently (92% samples) followed by metolachlor (66%) and endosulfans (49%). Although chlorothalonil is the single biggest contributor to pesticide flux (33-46%), pesticide wet deposition is dominated by herbicides (46-61%), with the greatest fluxes occurring during the time of herbicide application on corn and soybeans. The analysis suggests that the extent of wet deposition of herbicides depends on the timing of precipitation relative to herbicide application. The insecticide and fungicide flux was greater in years with above-average rainfall (2001 and 2003), suggesting that for these pesticides deposition flux is dependent on the total amount of rainfall in the agricultural season. The data indicate that the use of chlorpyrifos, an organophosphate insecticide which is on the Toxics of Concern list for the Bay, is on the increase. Total pesticide flux ranged from 90 microg/m2 (2001) to 180 microg/m2 (2000). Wet deposition can account for up to 10-20% of the annual loadings of pesticides to the Bay.

Agriculture↗
PubMed2005

Sorption and aging of corn and soybean pesticides in tropical soils of Brazil.

The efficacy and fate of pesticides in soil strongly depend on sorption reversibility that is known to decrease with increasing contact time (aging). We elucidated the aging dynamics of eight different pesticides in two contrasting agricultural soils of tropical Brazil (Ustox and Psamments), using batch equilibrium experiments and sequential extractions of field samples. Adsorption was best described by Langmuir isotherms for the entire and by Freundlich equations for the lower concentration range. In field samples, water extractable pesticide fractions mostly dissipated at least twice as fast as did the solvent extractable fractions. Hence, in comparison to 0 days K(OC) values, measured field K(OC) values were higher by a factor of 2.6-38 for the clayey Ustox and 2.1-72 for the sandy Psamments toward the end of the experimental period at 80 days after application. The extent of such aging basically increased with increasing polarity of the pesticide. An absolute enrichment of polar pesticides within the final exhaustive acetone--ethyl acetate--water extracts was observed during the experimental period, so that we may deduce that pesticides had redistributed into stronger sorption sites. The time course of the K(OC) development was well-described using a semiempirical equation, which had been employed for temperate soils before.

Adsorption↗