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PubMed2006

An ecological study of organochlorine pesticides and breast cancer in rural Victoria, Australia.

A number of studies have suggested that environmental contamination with organochlorine pesticides may be related to risk of breast cancer. To investigate this association in a rural part of Australia, organochlorine contamination data from a breast milk organochlorine study conducted in the state of Victoria in 1993 were used. The state was divided into 11 statistical divisions. Standardized incidence ratios (SIRs) for the 11 regions were calculated using breast cancer incidence data from 1983 to 2002. During that time, 47,250 breast cancer cases occurred in Victoria, which had an average population of 2,147,409 women. The Ovens-Murray region, which was the region most contaminated with organochlorine pesticides, showed an elevated SIR of 1.10 (95%CI, 1.03-1.17), although two other regions with lower organochlorine contamination levels also had elevated SIRs. The rural part of the Ovens-Murray region, where the main pesticide use occurred, had the highest SIR, 1.15 (95%CI, 1.07-1.23). We did not find any significant correlation between organochlorine contamination and the age-standardized rate of breast cancer across all regions. But a positive dose-response relationship using an adjusted negative binomial model was detected for heptachlor epoxide. Our study may provide limited support for the role of environmental contamination with organochlorine pesticides in the development of breast cancer.

Breast Neoplasms↗
PubMed1999

Pesticide deposition on coveralls during vineyard applications.

Deposition of pesticide on the clothing of the applicator was studied in a commercial vineyard using two different application technologies. A typical air-assisted sprayer with centrifugal fans delivered a concentrated spray. A tunnel or hooded sprayer was used at two carrier rates-high volume, low concentration versus low volume, high concentration-to apply Dithane M-45, an agricultural fungicide, at 3,375 g/ha on a light to medium density canopy. Deposition of pesticide was on the coveralls worn by the operator for all applications with a deposition range of 0.43 to 0.63 ng/cm2. The deposition on the clothing was higher for the air-assist sprayer than for the hooded sprayer. However, reducing the volume of water in the non-air assist hooded sprayer offered no advantage in terms of decreasing operator exposure. While the deposition of pesticide on the coveralls of the applicator was fairly uniformly distributed on the garment surface, the neck, shoulder, and upper right arm of our right-handed operator had the highest amount of pesticide deposit and the lower left quadrant of the garment had the lowest deposition. Results of this study indicate that vineyard applicator exposure can be reduced by use of the hooded non-air assisted sprayer and that extra protection is needed in the region of the neck, shoulder, and arm, and attention to the habits of the tractor driver is required.http://link.springer-ny. com/link/service/journals/00244/bibs/37n2p273.html

Agriculture↗
PubMed2006

Biological monitoring of exposure to organophosphate pesticides in children living in peri-urban areas of the Province of Quebec, Canada.

OBJECTIVE: This study was undertaken to assess the exposure to organophosphate (OP) pesticides in children from peri-urban areas of the Province of Quebec, Canada, through measurements of semi-specific alkylphosphate (AP) metabolites. METHODS: Eighty-nine children aged between 3 and 7 years were recruited via pamphlets sent to day-care centers. A first morning urine void was collected early in the spring of 2003 prior to summertime, which is the usual period of outdoor pesticide use. During summertime, up to five more first morning voids were repeatedly collected, at 72-h intervals, over a 13-day period. The potential determinants of exposure were assessed by a questionnaire at the time of urine collection. RESULTS: Methylphosphate metabolites were detectable in 98.2% of the 442 samples analyzed while ethylphosphates were detected in 86.7% of the samples. The geometric mean concentration (GM) of the total AP metabolites was 61.7 mug/g creatinine (range: 2.7-1967.3 mug/g creatinine). The difference in urinary AP concentrations between samples collected during spring and summer was non-significant (P=0.08). There was also no significant difference in the mean AP concentrations between summer samples of individuals living in municipalities where outdoor pesticide use is or is not restricted (P=0.25). However, the presence of a pet in the house was associated with an increase in AP concentrations during spraying season (P=0.02). Pesticides were seldom used, as reported by the questionnaire. A significant correlation was also observed (P<0.001) between the urinary AP concentrations in samples provided by siblings at the same time period. CONCLUSIONS: Mean concentrations of AP were generally higher than those reported in other studies. The observed exposure apparently occurred mainly through the dietary ingestion of OP residues. These data raise questions on the levels of OP residues in Quebec food and the possibility that our participants consumed more fruits and vegetables than those in other studies.

Child↗
PubMed2006

Production of Trichoderma strains with pesticide-polyresistance by mutagenesis and protoplast fusion.

The sensitivity of two cold-tolerant Trichoderma strains belonging to the species T. harzianum and T. atroviride was determined to a series of pesticides widely used in agriculture. From the 16 pesticides tested, seven fungicides: copper sulfate, carbendazim, mancozeb, tebuconazole, imazalil, captan and thiram inhibited colony growth of the test strains significantly with minimal inhibitory concentrations of 300, 0.4, 50, 100, 100, 100 and 50 microg/ml, respectively. Mutants resistant to carbendazim and tebuconazole were produced from both wild type strains by means of UV-mutagenesis. The cross-resistance capabilities and in vitro antagonistic properties of the mutants were determined. Carbendazim-resistant mutants showed total cross-resistance to benomyl and thiabendazole at a concentration of 20 microg/ml. Intraspecific protoplast fusion was carried out between carbendazim- and tebuconazole-resistant mutants of both parental strains, and putative haploid recombinants with stable resistance to both pesticides were produced in the case of T. atroviride. These pesticide-polyresistant progenies are potential candidates for application in an integrated pest management system.

Antibiosis↗
PubMed2005

Changes in salmonid communities associated with pesticide runoff events.

Two agricultural runoff events involving the pesticide azinphos-methyl occurred in July 2002 on the Wilmot River, Prince Edward Island, Canada, resulting in the death of thousands of fish. The fish communities from three sites on this river had been sampled in 2001, permitting comparisons of brook trout (Salvelinus fontinalis) and rainbow trout (Oncorhynchus mykiss) populations before and after the events. Samples taken immediately after the runoff events suggested that brook trout suffered higher mortality than rainbow trout. Young-of-the-year fish were more affected than older age classes for both species. Sampling in 2003, a year after the pesticide runoff events, revealed salmonid communities that were still skewed towards rainbow trout, and a decrease in the 1+ age class density (2002's young of the year) at affected sites. These results suggest a differential effect of the pesticide azinphos-methyl on salmonid species and age classes under natural conditions, and a subsequent change in population and community structure. The possibility of these pesticide runoff events selecting for rainbow trout, an exotic species, is a consideration in management of agriculturally impacted rivers.

Animals↗
PubMed2006

The effects of pesticides, pH, and predatory stress on amphibians under mesocosm conditions.

Pesticides are applied throughout the world often with unintended consequences on ecological communities. In some regions, pesticides are associated with declining amphibians, but we have a poor understanding of the underlying mechanisms. Pesticides break down more slowly under low pH conditions and become more lethal to amphibians when combined with predatory stress, but these phenomena have not been tested outside of the laboratory. I examined how pH, predatory stress, and a single application of an insecticide (carbaryl) affected the survival and growth of larval bullfrogs (Rana catesbeiana) and green frogs (R. clamitans) in outdoor mesocosms. Decreased pH had no effect on survival, but caused greater tadpole growth. Low concentrations of carbaryl had no effect on either species, but high concentrations caused lower survival and greater growth in bullfrogs. Predatory stress and reduced pH did not make carbaryl more lethal likely due to the rapid breakdown rate of carbaryl in outdoor mesocosms. Thus, whereas the stress of pH and predators can make carbaryl (and other pesticides) more lethal under laboratory conditions using repeated applications of carbaryl, these stressors did not interact under mesocosm conditions using a single application of carbaryl.

Amphibians↗
PubMed2006

Amperometric detection of pesticides using polymer electrodes.

The real time monitoring of some organophosphorus based pesticides is of great concern to environmentalists because the widespread use of pesticides is causing severe health hazards to all living beings and also hampering our ecological balance. The traditional methods of measurement of pesticide residues are time consuming, need sample pre-treatment, and lack desired specificity and accuracy. We have developed an amperometric biosensor for indirect measurement of the pesticide concentration precisely in ppb level. The method is based on the action of two enzymes namely acetylcholine esterase and choline oxidase which are uniquely immobilized in a polymeric porous network directly on the working electrode of a screen-printed sensor. Polyacrylamide matrix has been prepared by copolymerisation of acrylamide and N,N'-methylenebisacrylamide using Potassium peroxodisulphate (K2S2O8) as initiator. A linear relationship was obtained between the range of 0 to 10 ppb.

Acetylcholinesterase↗
PubMed2006

The status of pesticide residues in the drinking water sources in Meiliangwan Bay, Taihu Lake of China.

The study was carried out to assess the levels of pesticide residues in the water of Meiliangwan Bay, Taihu Lake of China. The most commonly employed organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs) and herbicide atrazine were analyzed. The water samples were collected seasonally from Meiliangwan Bay within a period of one year. The pesticides were analyzed by gas chromatography (GC) with microECD or NPD after solid-phase extraction (SPE), which was confirmed by GC with an ion trap mass spectrometry (MS). The mean concentrations were 1.98 ng/l for lindane, 0.378 ng/l for heptachlor epoxide, 0.367 ng/l for p,p'-DDE, 0.496 ng/l for p,p'-DDD, 1.06 ng/l for p,p'-DDT and 51.6 ng/l for dichlorvos, 39.0 ng/l for demeton, 346 ng/l for dimethoate, 4.12 ng/l for methyl parathion, 11.6 ng/l for malathion, 2.17 ng/l for parathion and 217 ng/l for atrazine. Generally, low concentrations of OCP were found, whereas the concentrations of the OPPs and atrazine in the water of Taihu Lake were relatively high. Heptachlor epoxide and lindane were the two most commonly encountered OCPs while dichlorvos, demeton and dimethoate were found to have much higher concentrations and occurrences than other OPPs.

Atrazine↗
PubMed1993

Solid-phase extraction in multi-residue pesticide analysis of water.

The determination of pesticides in water is fundamental to the solution of environmental problems as natural waters are usually contaminated with a large number of pesticides. The selection of an isolation and/or concentration technique depends largely on the class of pesticides to be determined. It is often necessary to determine simultaneously a wide variety of compounds in a water sample. Application of solid-phase extraction techniques offers a solution. The mechanisms of solid-phase extraction, types of sorbents and their application to multi-residue pesticide analysis are reviewed.

Chromatography↗
PubMed1993

Simultaneous analysis of 25 pesticides in crops using gas chromatography and their identification by gas chromatography-mass spectrometry.

The simultaneous analysis of 25 pesticides in soy beans and rices was performed by gas chromatography with dual electron-capture detection and nitrogen-phosphorus detection. The pesticides were extracted from the samples with solvent and the Bio-Beads S-X3 clean-up procedure was used. Recovery studies were performed at the 1-ppm level of pesticides added to each crop. Their recoveries ranged between 83 and 105% with coefficient of variations of 0.5-8.2%. The gas chromatographic properties of the 25 pesticides were also investigated. Conformation analysis was achieved by the retention time and characteristic fragment ions using the technique of gas chromatography-mass spectrometry-selected-ion monitoring.

Chromatography, Gas↗
PubMed1996

Determination of polar pesticides in ground water using liquid chromatography-mass spectrometry with atmospheric pressure chemical ionization.

A method is described for determination of pesticides in ground water by liquid chromatography combined with mass spectrometry (LC-MS) using atmospheric pressure chemical ionization (APCI). The study demonstrates the sensitivity of the technique, with detection limits for water samples of about 0.001-0.005 microgram/l, corresponding to 50-300 pg injected. Performance data for the method such as recovery, precision and linearity are also reported. It is illustrated that the technique is applicable for many different types of pesticide structures, such as triazines, phenylurea herbicides, acetanilides, organophosphorus insecticides, etc. Twelve different pesticides and pesticide degradation products are included in the study. The optimization of inlet conditions with respect to sheath gas pressure, vaporizer temperature, capillary temperature and corona current is reported. Applicability of the method for analysis of "real-world" ground water samples is demonstrated.

Chromatography, High Pressure Liquid↗
PubMed1996

Pesticide residue analysis in foodstuffs applying capillary gas chromatography with atomic emission detection state-of-the-art use of modified multimethod S19 of the Deutsche forschungsgemeinschaft and automated large-volume injection with programmed-temperature vaporization and solvent venting.

Atomic emission detection (AED) provides high element-specific detection of all compounds amenable to gas chromatography (GC). The heteroatoms nitrogen, chlorine, phosphorus, sulfur, bromine and fluorine, which are important elements in pesticide residue analysis, are of major interest. A main drawback of AED is its lower sensitivity with respect to other selective detection methods used in pesticide residue analysis such as electron-capture and nitrogen-phosphorus detection. This holds true especially for the important nitrogen trace. For this reason, more sensitive detection can be achieved by injection of larger volumes or higher concentrations of sample extracts, because matrix compounds were usually registered only in the carbon, hydrogen and oxygen traces. This paper focuses on recent developments from the authors' laboratory in order to demonstrate the feasibility of screening analyses with the identification of pesticide residues down to the 0.01 ppm concentration level in plant foodstuffs. This has been achieved by means of automated large volume injection with programmed-temperature vaporization and solvent venting as well as careful optimization of make-up and reactant gases with AED. Clean up follows the principle of multimethod S19 of the Deutsche Forschungsgemeinschaft in a reduced procedure. After elimination of lipids and waxes by gel permeation chromatography, extracts from 10 g of the food samples were concentrated to 200 microliters, of which 12.5 microliters were introduced into the GC-AED system. Two analyses were usually performed with the element traces of sulfur, phosphorus, nitrogen and carbon in the first run and chlorine and bromine in the second run. Fluorine and oxygen were not detected in any screening analyses. The method has proved to be of great value especially with "problem foodstuffs". The limits of detection were determined for 385 pesticides and are presented together with their retention data.

Chromatography, Gas↗
PubMed1995

Acute and prolonged toxicity to aquatic organisms of new and existing chemicals and pesticides.

The relation of acute to prolonged toxicity of existing and new chemicals and active ingredients of numerous pesticides in the aquatic environment have been compared with their physico-chemical properties. The data had been presented to the authorities in behalf of the pesticide registrations, the notification of new chemicals or research projects. The ecotoxicity ratios are expressed as acute to prolonged ratios (APR). They are determined for fish and crustacea with existing and new chemicals and pesticides. In the case of the pesticides the data are subsummarized into fungicides, herbicides, insecticides. The variability of the APR is evaluated. According to the statistic evaluation of the data it must be summarized, that the toxic effects are often extremely specific and depend not only on the substance, but also on the aquatic species, the duration of the exposure, and the endpoint of the test. In general, a factor of 100 between the EC/LC50 of acute toxicity and NOEC of prolonged toxicity is scientifically justified. The data indicate that there is no significant correlation between lipophilic properties (logPow) or water solubility and toxicity in aquatic organisms. For that reason structure-activity relationships based on lipophilic properties of the substance cannot lead to reasonable results. It must be stated, that the prolonged ecotoxicity can not be exactly extrapolated from acute toxicity data on the basis of physico-chemical properties.

Animals↗
PubMed1995

Uniform System for the Evaluation of Substances. V. ESPE, risk assessment for pesticides.

This article is the fifth in a series concerning the Uniform System on the Evaluation of Substances (USES). An integral part of USES is the Evaluation System for PEsticides (ESPE). The systems deals with the current practice in The Netherlands concerning the hazard and risk estimation of substances for which a governmental decision is needed before a substances can be marketed or used in The Netherlands, also taking into account EU-legislation. For pesticides a distinction is made between agricultural and non-agricultural pesticides. Both types of substances can be considered in USES. Surface water contamination of pesticides after application on arable land and lixivation of antifouling paints from boats into the water of a harbour show as an example how certain aspects are handled.

Agrochemicals↗
PubMed1992

Criteria for evaluating the impact of pesticides on groundwater quality.

A lot of data and information are available regarding the presence of pesticides in ground-waters or their tendency to contaminate them. Despite this, for a very large number of pesticides these data and information are almost completely lacking. Many theoretical methods have been proposed to predict the leaching potential of pesticides. Persistence (expressed by DT50) and mobility (expressed by Koc) are key parameters that seem to be particularly representative of the overall leaching potential of nonionic compounds and they are widely used in these methods. Nevertheless, these parameters may vary greatly causing sharp differences in ranking the leaching potential of pesticides. Indeed, when the GUS Index is calculated using the available published values of Koc and DT50 in combinations representing the minimum, medium and maximum leaching potential of herbicides, very different results can be obtained. Many of these compounds can be classified as contaminants or non contaminants, depending on the type of combination used.

Pesticides↗
PubMed1993

Environmental aspects of pesticide use in Italian agriculture.

Pesticides used in agriculture accumulate in organisms and reach man through complex metabolic pathways. Accurate analysis of pesticides presence in each step of the food chain is necessary because of the high number of these substances, their potential toxicity and the presence of amplified toxic effects due to synergic interactions. In the same way it is necessary to evaluate the environmental effects of the whole pesticides cycle, from industrial production until final disposal of used containers and residuals. Furthermore recent introduction of new categories of chemicals which are not strictly classifiable as pesticides (photosynthetic activity stimulators, aesthetic aspect enhancers) and not yet sufficiently studied in their metabolic behaviour, increase the problem complexity. Complete studies about these complex problems and about the effects on ecosystems have not yet been carried out in Italy, due to ambiguous laws and regulations, inadequate data collection methods and decisional influence of the chemical industry on agriculture policy.

Agriculture↗
PubMed1985

Effects of pesticides and drugs on working memory in rats: continuous non-match.

Effects of four pesticides (carbaryl, propoxur, chlordimeform, and deltamethrin) and two reference drugs, physostigmine and chlordiazepoxide, were measured on the performance of rats trained on a continuous non-match (CNM) delayed comparison, working memory procedure. These same compounds were also tested in analogous, large and small stimulus difference discrimination (i.e., non working-memory) procedures. The effects of the pesticides and physostigmine on CNM performance were qualitatively similar, and also similar to their effects on discrimination performance. As dosage of these compounds increased, only small effects on accuracy were observed, followed at still larger doses by an abrupt and non-selective decrease in all responding. The pesticides and physostigmine did not selectively affect working memory: the magnitude of their effects did not increase with intertrial interval, and the compounds were equally effective in disrupting discrimination and CNM performance. Effects of chlordiazepoxide on performance in the CNM and discrimination control procedures differed qualitatively from those of the pesticides and physostigmine.

Animals↗
PubMed1994

An analysis of avian reproduction studies submitted for pesticide registration.

Avian reproduction studies are currently part of the regulatory ecotoxicology requirements for pesticides in many countries. In the study, 134 avian reproduction studies were reviewed to determine their ability to identify pesticides that have the potential to affect reproduction in wild birds. A clustering procedure was first used to assign measured variables to parental, developmental, or eggshell effects. This assignation was found to be identical in the two bird species tested. Nineteen of 69 pesticides tested were found to cause developmental effects at levels lower than those giving rise to detectable parental toxicity. At least some of these should not have been registered without some assurance that developmental effects would not occur in the wild. The analysis also found very little similarity in the effects of pesticides on the two bird species commonly used in avian reproduction tests. This casts serious doubts on the ability to extend the results of avian reproduction studies to any potentially affected bird species. Modifications to the avian reproduction test, based on results of the analysis conducted, are suggested. It is recommended that the avian reproduction study be recognized as a rough screening tool only and that efforts not be made to make it more realistic, e.g., such as through a reduced exposure period.

Animals↗