Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PESTICIDES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,603 records · Page 89Linked to original sources
PubMed2001

Levels of organochlorine pesticide residues in some organs of the Ganges perch, Lates calcarifer, from the Ganges-Brahmaputra-Meghna Estuary, Bangladesh.

Levels of organochlorine pesticide residues (p,p' DDT, DDD, DDE, Aldrin, Dieldrin, Lindane, Heptachlor and BHC) were analysed in the dry and wet seasons in four organs (muscle, liver, gut and egg samples) of Ganges Perch, Lates calcarifer, collected during October-November-December, 1996 and May-June-July, 1997 from the Ganges-Brahmaputtra-Meghna estuary. The residues were analysed by using gas-chromatography (GC) in electron capture detector (ECD) mode and were verified by thin layer chromatography (TLC). Among the four organs analysed, the residues were found in the order egg > gut > muscle > liver. The pesticide residues were found in the order sigmaDDT > Heptachlor > Dieldrin > Aldrin. Higher levels of residues were found during the dry season due to high lipid content in fishes. A positive correlation was observed between the pesticide residues (sigmaDDT and sigmaOCs) and lipid contents of fish, and the correlation was found to be linear. The concentrations of pesticide residues in muscle, liver and gut were below the FAO/WHO (1993) recommended permissible limit except in eggs.

Adipose Tissue↗
PubMed2002

The significance of entry routes as point and non-point sources of pesticides in small streams.

In an agricultural catchment area in Germany we analyzed water samples from five entry routes for 2 insecticides. 5 fungicides and 13 herbicides. The sewage plant outlet and the emergency overflow of a sewage sewer contained only herbicides. In each farmyard runoff we found on average 24 g pesticides during application period, presumably caused by cleaning the spraying equipment. In comparison, the field runoff and the rainwater sewer contained less load, but also insecticides, fungicides and herbicides. The sewage plant caused 65.9% of the total herbicide load, the sewage sewer 19.8% and the farmyard runoff 12.8%. The farmyards also caused 83.7% of total insecticide and 83.8% of fungicide load. The total load of all entry routes is correlated with the amount of pesticides applied in the catchment area and the Ko/w value for each pesticide (mult. regress. r2: 0.82; p<0.0001; n = 14). In stream A the sewage plant caused a slight but continuous contamination by herbicides with 82% of the total load found during low-water phases. In comparison, stream B had only farmyard runoff and non-point sources, which caused high peaks of herbicide and a contamination by insecticides. Consequently, high-water phases generated 70% of the total pesticide load.

Agriculture↗
PubMed2001

Distribution of organochlorine pesticides in soils from South Korea.

Soil samples were collected from rice growing and industrial areas in South Korea and analysed for organochlorine pesticide content using gas chromatography with electron capture detection. The soils were monitored for the presence of 18 organochlorine pesticides. The main pesticides found were gamma- and delta-hexachlorocyclohexane, heptachlor epoxide and dieldrin. The range of concentrations, for each compound, was respectively, 0.17-0.94, 0.77-2.97, 1.38-48.0 and 0.32-0.49 ng/g soil. The highest values were found in soil obtained from rice fields indicating that, although the use of organochlorine pesticides has been discontinued since 1980, substantial concentrations of residues particularly the oxidised form of heptachlor remain in the soil.

Agriculture↗
PubMed2001

Screening of compost for PAHs and pesticides using static subcritical water extraction.

Static subcritical water extraction (SubWE) along with solid phase extraction (SPE) was used for the analysis of PAHs and pesticides in municipal solid waste compost. Yields obtained for PAHs in certified reference sediment (CRM 104) were acceptable. The extraction method was simple, rapid, used small sample sizes, and no sample drying was required. Analysis of samples was performed by GC/MS and HPLC. Recovery of spiked pesticides was greatest at 110 degrees C for 20 min extraction time. The optimum extraction for PAH analysis was achieved at 150 degrees C for 20 min. Addition of C-18 resin as an "alternate sorbent" upon cooling increased recovery of PAHs but not of pesticides, however, it increased the stability of atrazine and propazine at higher temperatures. Analysis of three municipal compost samples from the Dayton, OH (USA) area showed no pesticides above the detection limit, however, PAH totals for 11 PAHs were 15.97, 14.42, and 20.79 microg g(-1). The totals of six of the seven carcinogenic PAHs, for which remediation goals in the United States is 4.6 microg g(-1), were determined to be 9.89, 6.77, and 13.06 microg g(-1) dry weight. The highest PAH totals were obtained from compost containing sewage sludge.

Carcinogens↗
PubMed2001

Pesticide influence on soil enzymatic activities.

The influence of four pesticides, e.g. glyphosate, paraquat, atrazine, and carbaryl, on the activities of invertase, urease and phosphatase of twenty-two soils, numbered as 1-22, was investigated. Soils displayed a general variability of enzyme activities with invertase being more abundant than urease and phosphatase in the order listed. The addition of glyphosate and paraquat activated invertase and urease activities in several soils. Increments of invertase activity ranged from a very low increase (+4%) up to +204% in soils 11 and 14, respectively. Smaller increases were measured for urease. A general inhibitory effect (from 5% to 98%) was observed for phosphatase in the presence of glyphosate. The effects of atrazine and carbaryl on the three soil enzymes were evaluated against that exhibited by methanol, the solvent used for their solubilization. In almost all soils, atrazine further inhibited invertase activity with respect to the inhibitory effect shown by methanol. By contrast, consistent activation effects (from 61% to 10217%) were measured for urease with methanol alone and/or methanol-pesticide mixtures. Contradictory results were observed with phosphatase. Similarities found between the results obtained with enzymes in soils and those measured with synthetic enzyme complexes (e.g. free enzymes and/or clay-, organo-, and organo-clay-enzyme complexes) exposed to the same pesticides allowed some relationships between responses of soil enzymes to pesticides and soil properties to be hypothesized.

Environmental Monitoring↗
PubMed2002

Screening of pesticides for environmental partitioning tendency.

The partitioning tendency of chemicals, in this study pesticides in particular, into different environmental compartments depends mainly on the concurrent relevance of the physico-chemical properties of the chemical itself. To rank the pesticides according to their distribution tendencies in the different environmental compartments we propose a multivariate approach: the combination, by principal component analysis, of those physico-chemical properties like organic carbon partition coefficient (Koc), n-octanol/water partition coefficient (Kow), water solubility (Sw), vapour pressure and Henry's law constant (H) that are more relevant to the determination of environmental partitioning. The resultant macrovariables, the PC1 and PC2 scores here named leaching index (LIN) and volatality index (VIN), are proposed as preliminary environmental partitioning indexes in different media. These two indexes are modeled by theoretical molecular descriptors with satisfactory predictive power. Such an approach allows a rapid pre-determination and screening of the environmental distribution of pesticides starting only from the molecular structure of the pesticide, without any a priori knowledge of the physico-chemical properties.

Biological Availability↗
PubMed1999

A field study to compare performance of stainless steel research monitoring wells with existing on-farm drinking water wells in measuring pesticide and nitrate concentrations.

Existing drinking water wells are widely used for the collection of ground water samples to evaluate chemical contamination. A well comparison study was conducted to compare pesticide and nitrate-N data from specially designed stainless steel research monitoring wells with data from nearby existing on-farm drinking water wells. Results could help to determine whether adequate information concerning ground water contamination can be obtained from existing drinking water wells for use in making pollutant control decisions. The study was conducted during 1993-1994 in the Little Coharie Watershed, a 158 square mile area located in the coastal plain of eastern North Carolina. Statistical analysis indicated that research monitoring wells provided a greater probability of detecting pesticides in ground water than existing on-farm wells. Atrazine was the most frequently detected pesticide found in all wells, followed in order by fluometuron, carbofuran, metolachlor, alachlor, carbaryl, butylate, chlorothalonil, linuron and simazine. Ninety-seven percent of all wells had observed concentrations of nitrate-N, ranging from 0.1 to 30.1 mg/L. There was not a significant difference between research wells and existing wells for monitoring nitrate-N. Based on results of this study, existing drinking water wells can be used for monitoring nitrate; however, specialized stainless steel monitoring wells should be used for monitoring pesticides in ground water.

Databases, Factual↗
PubMed2000

Enzymatic and osmoregulative alterations in white shrimp Litopenaeus vannamei exposed to pesticides.

Pesticide pollution in coastal ecosystems of Sinaloa, Mexico is considered to be a cause for slow growth, increase of diseases and sometimes massive mortality of shrimp. So it was necessary to develop fast techniques to detect pesticide pollution in shrimp habitats. Enzymatic and osmoregulation tests in shrimp exposed to DDT, Lindane, Chlordane, Lorsban, Gusathion, Folidol, Diazinon and Tamaron were carried out. Activity reductions from 11 to 2 units/ml in acetylcholinesterase and from 1 to 0 units/l in transaminases (GOT and GPT) were detected. Also increases in osmoregulation were observed in shrimp exposed to Folidol, Diazinon and Gusation, whereas decreases with DDT, Lindane and Lorsban at salinity 50/1000. We conclude that pesticides are causing alterations in these biochemical functions and this kind of tests represent a rapid and inexpensive method for pesticide pollution detection.

Acetylcholinesterase↗
PubMed2000

Riverine fluxes of the persistent organochlorine pesticides hexachlorcyclohexane and DDT in the Russian Federation.

The contribution of gross riverine organochlorine pesticide (OCP) transport to estuaries of Russian seas and Lake Baikal was determined to help understand OCP transboundary transfer and to provide a basis for estimating Russia's contribution to global pollution by these pesticides. The official OGSNK/GSN data ranks sea/ocean/lake basins in the following order based upon the amounts of total OCPs received from agricultural use: Eastern Arctic>Western Arctic>Pacific>Baltic>Caspian>Azov/Black>Baikal. A similar ranking was obtained using an independent set of data: Eastern Arctic>Pacific>Caspian>Western Arctic>Baltic>Azov/Black. In terms of riverine flow-associated discharge of HCH isomers (i.e., sum of alpha-, beta- and gamma-HCH) estuaries of the Kara, Okhotsk and Beloye (White)/Barents seas received more pesticides than other seas. No HCH was discharged to estuaries of the Eastern Siberian and Bering seas. For DDT and its derivative (DDE), estuaries of the Kara, Caspian, Okhotsk and Baltic seas received the greatest amounts. During our study period (1988-1996), HCH transport was more prevalent in the majority of rivers reflecting both the official ban on the use of DDT in the former Soviet Union and the greater popularity of HCH as a pesticide. In general, it appears that Russian rivers play a significant role in OCP contamination of some estuaries of regional seas, especially those of the eastern Arctic basin, such as the Kara Sea.

DDT↗
PubMed2006

Continuous pralidoxime infusion versus repeated bolus injection to treat organophosphorus pesticide poisoning: a randomised controlled trial.

BACKGROUND: The role of oximes for the treatment of organophosphorus pesticide poisoning has not been conclusively established. We aimed to assess the effectiveness of a constant pralidoxime infusion compared with repeated bolus doses to treat patients with moderately severe poisoning from organophosphorus pesticides. METHODS: 200 patients were recruited to our single-centre, open randomised controlled trial after moderately severe poisoning by anticholinesterase pesticide. All were given a 2 g loading dose of pralidoxime over 30 min. Patients were then randomly assigned to control and study groups. Controls were given a bolus dose of 1 g pralidoxime over 1 h every 4 h for 48 h. The study group had a constant infusion of 1 g over an hour every hour for 48 h. Thereafter, all patients were given 1 g every 4 h until they could be weaned from ventilators. Analysis was by intention to treat. Primary outcome measures were median atropine dose needed within 24 h, proportion of patients who needed intubation, and number of days on ventilation. The study is registered at http://www.clinicaltrials.gov with the identifier NCT00333944. FINDINGS: 100 patients were assigned the high-dose regimen, and 100 the control regimen. There were no drop-outs. Patients receiving the high-dose pralidoxime regimen required less atropine during the first 24 h than controls (median 6 mg vs 30 mg; difference 24 mg [95% CI 24-26, p<0.0001]). 88 (88%) and 64 (64%) of controls and high-dose patients, respectively, needed intubation during admission to hospital (relative risk=0.72, 0.62-0.86, p=0.0001). Control patients required ventilatory support for longer (median 10 days vs 5 days; difference 5 days [5-6, p<0.0001]). INTERPRETATION: A high-dose regimen of pralidoxime, consisting of a constant infusion of 1 g/h for 48 h after a 2 g loading dose, reduces morbidity and mortality in moderately severe cases of acute organophosphorus-pesticide poisoning.

Adult↗
PubMed1997

Clinical evaluation of pesticide exposure and poisonings.

Pesticide exposures cause disorders varying from straightforward topical irritant reactions, such as those to synthetic pyrethroid insecticides, to complex systemic illness, such as that resulting from cholinesterase inhibition by organophosphate pesticides. The acute illness syndromes associated with pesticides most commonly encountered by clinicians are illustrated here by cases reported to the California Pesticide Illness Surveillance Program. The issues raised include asthma associated with exposure to contaminants in organophosphate insecticides, systemic toxicity of ingested pyrethroids (in children), and illnesses associated with spills or misuse of fumigants.

Carbamates↗
PubMed2003

Use of geographic information systems for assessing groundwater pollution potential by pesticides in Central Thailand.

This study employed geographic information systems (GIS) technology to evaluate the vulnerability of groundwater to pesticide pollution in Thailand. The study area included three provinces, Kanchana Buri, Ratcha Buri, and Suphan Buri, located in west-central Thailand. Factors used for the vulnerability assessment included soil texture, slope, land use, well depth, and rainfall. These vulnerability factors were reclassified to a common scale, and a weighted average was computed to yield a vulnerability score. Vulnerability factors and weights were assigned considering pesticide concentrations in 90 wells throughout the study area. Well depth was the most significant vulnerability factor. Groundwater vulnerability maps were generated for several pesticides. The eastern, agricultural part of the study area has relatively deep wells and fine soils. Shallow wells are present in the mountainous west; however, fewer pesticides are applied in that region. Consequently, much of the study area had a medium groundwater vulnerability rating, although there were pockets of high vulnerability, for example, in agricultural areas with shallow wells. The groundwater vulnerability maps are effective for identifying locations warranting more detailed groundwater pollution and vulnerability investigations.

Agriculture↗
PubMed1998

The use of live biocatalysts for pesticide detoxification.

During the past decade, numerous microorganisms capable of degrading pesticides have been isolated, and detoxification processes based on these live biocatalysts have been developed. Recently, novel detoxification strategies using genetically engineered microorganisms with extended degradative capabilities have been investigated and, in some cases, shown to be more effective. One promising approach for the detoxification of organophosphate pesticides uses genetically engineered Escherichia coli with surface-expressed organophosphorus hydrolase. Continuous efforts in this direction are required, in conjunction with a search for microorganisms capable of degrading pesticides rapidly, to establish efficient and cost-effective large-scale processes for pesticide detoxification.

Bacteria↗
PubMed2001

Gross fluxes and estuarine behaviour of pesticides in the Scheldt estuary (1995-1997).

As part of the Fluxes of Agrochemicals into the Marine Environment (FAME) project, the gross fluxes of selected pesticides (i.e. the herbicides atrazine, simazine, alachlor and metolachlor, the atrazine degradation product desethylatrazine, the insecticide dichlorvos and the antifouling agent Irgarol 1051) transported by the river Scheldt and the Canal Ghent-Terneuzen were determined from March 1995 through February 1997. In general, the observed temporal trends were related to the application period of the pesticides, except for metolachlor for which elevated concentrations were observed in the winter of 1995-1996. Relatively large gross fluxes were found for desethylatrazine compared with its parent compound. A study on the estuarine behaviour of pesticides showed distinct differences between the compound classes. The mixing plots of the organophosphorus insecticides dichlorvos and diazinon revealed clear evidence of estuarine loss processes which agrees with their low DT50 values reported for water/sediment systems, their relatively high Henry's law constants and, for diazinon, its relatively high Koc value. The mixing plots of the acetanilides alachlor and metolachlor were strongly influenced by an additional direct emission into the estuary, which was evident from a maximum in dissolved concentration near a salinity of 10@1000. An apparent conservative behaviour was observed for the triazine compounds atrazine and Irgarol 1051. This was in contrast to simazine, which showed an apparent non-conservative behaviour. However, the time profiles of the riverine concentrations of simazine did not exclude that the observed curvature was solely caused by estuarine losses; therefore, additional modelling is required. In a follow-up study a suitable hydrological model of the Scheldt estuary was constructed; the results will be presented in a forthcoming paper (Steen, R.J.C.A., Evers, E.H.G., Van Hattum, B., Cofino, W.P. and Brinkman, U.A.Th. Net fluxes of pesticides from the Scheldt estuary into the North Sea: a model approach. Environmental Pollution, submitted.

England↗
PubMed2002

Net fluxes of pesticides from the Scheldt Estuary into the North Sea: a model approach.

A hydrological model was constructed with the commercially available modelling environment ECoS for the calculation of mixing plots of dissolved pesticide concentrations in the Scheldt Estuary. The model was based on a one-dimensional advection-dispersion equation and dispersion coefficients were calculated from measured salinity profiles. The model could correctly predict the movement of water masses within the estuary. Nominal flushing times of the estuary were calculated with the fraction-of-freshwater method and ranged between 25 and 95 days, depending on the freshwater discharge. Model calculations demonstrated that the application-related time profiles of pesticide input may well induce curvature in the calculated estuarine mixing plot even if the pesticide behaves conservatively. Calculated mixing plots were compared with experimental data and good agreement was obtained between the measurements and the conservative mixing plot of atrazine. For metolachlor an additional direct emission had to be modelled to explain the differences between the experimental data and the conservative mixing plot. For dichlorvos and simazine. on the other hand, an estuarine loss constant had to be included in the model. Using a least-squares procedure the estuarine loss constants for dichlorvos and simazine were estimated at half-lives of five and 26 days, respectively. Because mixing plots were strongly influenced by the time profiles of pesticide input, standard procedures in which net fluxes are calculated from mixing plots, were not applicable. Therefore, net fluxes were calculated with a newly developed procedure in which the estuarine loss constants and the estuarine flushing time were combined. For the non-conservative compounds dichlorvos and simazine, the net fluxes to the North Sea were found to be 96 and 64%, respectively, lower than the gross fluxes transported by the River Scheldt.

Agriculture↗
PubMed2003

Di-alkyl phosphate biomonitoring data: assessing cumulative exposure to organophosphate pesticides.

The 1996 Food Quality Protection Act (FQPA) requires the evaluation of both aggregate and cumulative health risks from pesticides (FFDCA 408(b)(2)(D)(v) and (vi).) Organophosphate (OP) pesticides are the first class of chemicals to undergo FQPA mandated aggregate and cumulative assessments. In this report, summary data on biomonitoring for urinary levels of six alkyl phosphate (AP) metabolites of OPs, as reported in the initial, March 2001, U.S. Centers for Disease Control and Prevention's (CDC) "National Report on Human Exposure to Environmental Chemicals," are compared to EPA modeled estimates of OP exposure reported in Registration Eligibility Decision documents (REDs), Interim REDs and to currently reported cumulative exposure estimates in the EPA's Cumulative Risk Assessment of the Organophosphate Pesticides. This comparison indicates that EPA's aggregate exposure estimates (dietary, drinking water, and non-dietary residential exposures) for many individual OPs were greater than the cumulative estimate for all OPs combined based on the CDC AP biomonitoring data. The results also suggest that EPA's screening level assessments of OPs, while being qualitative indicators of the relative importance of various exposure sources, are not good quantitative indicators of actual exposures. However, the mean biomonitoring estimate of cumulative OP exposure appears to exceed the EPA's subsequent preliminary estimate of cumulative OP exposure by as much as the REDs appear to overestimate the biomonitoring results. While the conservatism, tendency to overestimate exposure, in the individual REDs is readily acknowledged, the conservatism and limitations of applying currently available CDC AP biomonitoring data to evaluate human exposure to OPs are not as readily apparent. We postulate that oral absorption of non-anti cholinergic, pre-hydrolyzed OPs, sources of APs other than pesticides, and the conservative result of summing exposure from each AP at the geometric mean contribute to non-quantified overestimates of absorbed dosage from the CDC biomonitoring data reported in March 2001. CDC AP biomonitoring data may serve a useful purpose in providing an upper bound estimate of absorbed dosage for "ground truthing" aggregate exposure estimated from first tier models used in REDs, but at best may provide only a credible "target" for the complex cumulative exposure assessment models currently under development. The reliability of quantitative estimates of OP exposure levels will improve as cumulative risk exposure models are validated over time and under use conditions prevalent at the time the AP biomonitoring samples are collected. Analyses contained herein should be revisited and compared to the CDC Second National Report on Human Exposure to Environmental Chemicals ( http://www.cdc.gov/exposurereport), released to the public on January 31, 2003, and the final EPA OP Cumulative Risk Assessment.

Environmental Exposure↗
PubMed1999

Binding capacity of various fibre to pesticide residues under simulated gastrointestinal conditions.

The purpose of this study was to compare the effect of the nature and quantity of various dietary fibre (cellulose, hemicellulose, pectin, lignin) in diets on the binding capacity to pesticides azinphos-methyl (AZM), chlorpropham (CLP), chlorothalonil (CKL), permethrin (PER) as estimated by solubility under conditions of pH and temperature simulating those in the gastrointestinal tract (incubated at pH 2 for 30 min at 37 degrees C, then at pH 7 for 60 min). The ratios of fibre to pesticides were determined in omnivorous diets. In this model, the binding capacity of lignin was equal to hemicellulose for PER, AZM and CLP, but it was significantly higher for CKL. Hemicellulose bound more CKL, AZM and CLP than did cellulose. Although pectin appreciably decreased all pesticides, its effect was lower than other fibres with one exception--cellulose-CKL. In the presence of equal amounts of fibre, lignin exerted the most significant effect on pesticide solubility. Hemicellulose and cellulose bind to the same extent PER and AZM. The effect of pectin was significant only on CKL and AZM when compared to the control.

Adult↗
PubMed2001

Cytogenetic monitoring of croatian population occupationally exposed to a complex mixture of pesticides.

This paper describes a longitudinal study of possible genetic damage in Croatian workers occupationally exposed to a complex mixture of pesticides. The methods of choice were chromosomal aberration analysis, sister chromatid exchange analysis (SCE), micronucleus assay and comet assay. In order to determine primary genotoxic effects in workers, blood samples were taken after the workers spent 8 months in the production of pesticides. During the production all subjects were simultaneously exposed to a complex mixture of pesticides containing atrazine, alachlor, cyanazine, 2,4-dichlorophenoxyacetic acid, and malathion. To detect DNA repair in lymphocytes of the same subjects the second series of blood samples was taken 8 months after the workers were removed from production. Regardless of the time sampling time the exposed workers showed an increased number of chromosomal aberrations, SCE frequency, micronucleus (MN) frequency, and values of comet assay parameters. After 8 months of non-exposure the workers showed a significantly decreased number of chromosomal aberrations, MN frequency, and DNA migration compared to the results of the first sampling, but it was still significantly higher than in controls. Furthermore, the SCE frequency in the exposed subjects did not drop after the 8 months of non-exposure, which indicates long-term exposure to a mixture of pesticides.

Adult↗