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At least 991 records · Page 55Linked to original sources
PubMed2006

[Determination of organochlorine pesticide residue in nine Chinese herbs by gas chromatography].

OBJECTIVE: To determine organochlorine pesticide residue in 9 Chinese herbs. METHODS: The organochlorine pesticides were extracted from the herbs with mixed solvents of n-hexane and acetone by a solid-phase extraction cartridge Florisil. Capillary gas chromatography was used to separate the samples. RESULTS: Good linearities were obtained for 11 organochlorine pesticides. The average recoveries at two concentration levels ranged from 79.9% to 89.0%,and from 86.3% to 104.8%, with relative standard deviations of 1.8% to 7.1%, respectively and detection limit of 2 g/kg. The residues of the organic pesticides exceeded national standard in Pogostemon cablin and Panax notoginseng. CONCLUSION: Capillary gas chromatography combined with electron capture detection provides a practical means for detecting organic pesticide residue in Chinese herbal medicines, and the limits of pesticide residues should be formulated in Chinese pharmacopoeia.

Chromatography, Gas↗
PubMedDate not supplied

Spirometric changes following the use of pesticides.

We compared the respiratory function of 19 pesticide factory workers and a control group of 43 other factory workers in Lebanon. The groups had no difference in smoking status. Baseline measurements of respiratory function showed significantly lower forced expiratory volume and flow rates (FEV1, FEF(25-75%), and FEV1/FVC ratio) among subjects working with pesticides, i.e. obstruction may be linked to chronic exposure to pesticides. After 4 hours of work, all respiratory variables were still significantly lower in pesticide-exposed subjects, but no acute changes in respiratory function were seen. Pesticide-exposed workers had 5.6 times higher risk of abnormal FEV1/FVC ratio and 16.5 higher risk for abnormal FEF(25-75%). Duration of occupation in the pesticide factory was significantly correlated with abnormal respiratory measures.

Adult↗
PubMed2006

[Multiresidue determination of organophosphorus pesticide residues in vegetables and fruit by gas chromatography-negative ion chemical ionization-mass spectrometry].

An analytical method of gas chromatography coupled with negative ion chemical ionization-mass spectrometry for simultaneous determination of nine organophosphorus pesticide residues in vegetables and fruit has been developed, and the negative ions structure and partition mechanism of the nine organophosphorus pesticides were interpreted. Meanwhile, the matrix effect for sample analysis was discussed, and matrix-matched calibration for quantification was introduced to reduce the matrix effect in this method. Pesticides were extracted from sample with ethyl acetate in an ultrasonic bath, then determined by gas chromatography-mass spectrometry operated in negative chemical ionization mode and quantified in selective ion monitoring mode, and ethion was used as an internal standard. The detection limits of the method were 0.12-1.0 microg/kg for the nine organophosphorus pesticides, and the relative coefficients were higher than 0.9993. A blank sample (tomato) was spiked at 100, 400, 800 microg/kg for each pesticide, and the recoveries were determined to be from 78% to 126% with relative standard deviations from 0.58% to 14.7% for the pesticides.

Agriculture↗
PubMedDate not supplied

[Mortality due to cancers of the brain and lymphatic tissues and leukemia as a function of agriculture pesticide use in Quebec (1976-1985)].

Potential hazards associated with the use of agricultural pesticides are a growing concern for society. We describe the relationships between the mortality data for cancers of the brain, the lymphatic tissues and leukemia, and the spatial distribution of agricultural pesticide use for 34 drainage basins in Quebec, from 1976-1985. The basins were grouped into three categories (low, intermediate, and high exposure) according to the level of sales of pesticides. For cancers of the lymphatic tissues among women 35 to 64 years of age, a high relative risk (RR) was observed (RR = 1.91, 95% Confidence Interval = 1.14, 3.18) in basins highly exposed to pesticides compared to those with low exposure. Analysis of correlation for this cancer at 34 basins showed significant associations between geographical distributions of the Standardized Mortality Ratio (SMR) and those of numerous variables indicative of pesticide use in agriculture. Agreement between the results for mortality data in this exploratory study and the results from another study on cancer incidence data for 1982-1983, supports the hypothesis of a potential relationship between the use of pesticides in agriculture and cancer of the lymphatic tissues.

Adult↗
PubMedDate not supplied

Codex alimentarius approach to pesticide residue standards.

To protect consumers' health, most countries have maximum legal limits for pesticide residues in foods. Trade difficulties can arise when limits differ between countries. The Codex Alimentarius Commission was established in 1962 to implement the Joint FAO/WHO Food Standards Programme, the purpose of which is to protect consumer health and ensure fair practices in international food trade. The Codex Committee on Pesticide Residues (CCPR), an intergovernmental body which advises the Commission on matters related to pesticide residues, is responsible for establishing maximum residue limits (MRLs) for pesticides in foods and feeds that move in international trade. Codex MRLs are based on residue data obtained mainly from supervised trials that reflect approved pesticide use in accordance with "good agricultural practice." MRLs must be toxicologically acceptable in terms of estimated pesticide intake by consumers. CCPR Working Groups examine problems related to establishing and implementing MRLs, including sampling and methods of analysis. Despite time and effort expended, acceptance and application of Codex MRLs face many problems in international trade.

Food Contamination↗
PubMedDate not supplied

Pesticides and healthy public policy.

Despite concern over long-term human and environmental health risks, Canadian and international pesticide use continues to increase. Enormous gaps in pesticide toxicity data persist and, though equivocal, there is mounting evidence that certain pesticide families are carcinogenic. Farmworkers are at greatest risk of pesticide poisoning and long-term health effects, and unions representing farmworkers have initiated a boycott of California grapes to draw attention to the need to reduce pesticide use and improve health and safety conditions. The boycott is a model of "healthy public policy" in action, and can be one element in a public health strategy to reduce significantly pesticide use and promote less toxic alternatives and less chemically dependent forms of agriculture and silviculture.

Canada↗
PubMed1979

Organochlorine pesticide residues in human milk samples from women living in Northwest and Northeast Mississippi, 1973-75.

Organochlorine pesticide analyses were performed on human milk samples obtained from 34 women living in the Mississippi Delta, a high pesticide usage area, and from six women living in Starkville, Mississippi, a low pesticide usage area. Nine women collected samples before and after their babies had nursed so that fat levels and sigma DDT levels could be compared on whole milk and milk fat bases. sigma DDT values were independent of collection time if calculated on a milk fat basis, but not if calculated on a whole milk basis. Thus, the most consistent indicator of DDT residues were values calculated on a milk fat basis. Residue levels for p,p'-DDE, p,p'-DDT, and sigma DDT were significantly different (P less than 0.01) in samples from the two areas. Residues of o,p'-DDT, beta-BHC, and oxychlordane in milk samples from women living in the high pesticide usage area also were significantly different (P less than 0.05). A mean value of 19.17 ppm sigma DDT, found in the milk fat of samples from the high pesticide usage area, is the highest ever reported. Samples from the low pesticide usage area contained a mean level of 2.36 ppm sigma DDT.

Adult↗
PubMed1982

Toxicological classification of pesticides.

The authors put forth their proposition for pesticide classification from the points of view of acute toxicity, skin irritation, skin toxicity 'resorption), cummulation coefficient and chronic effect--anticipated chronic risk. The proposition of this kind may be considered a priority in Czechoslovakia. It is confronted with the criteria for pesticide classification recommended by the WHO which it suitably completes. Acute toxicity makes it possible to classify pesticides into five classes: class I - highly toxic, class II - toxic, class III - moderately toxic, class IV - slightly toxic, class V - virtually non-toxic. Skin irritation enabled to classify pesticides as highly irritant, irritant, moderately irritant, slightly irritant and non-irritant. For skin toxicity 3 degrees were used: those of very good resorption, good resorption and low resorption. The proposition fr classification is supplemented by cummulation coefficient and the aspect of chronic effect. In the present study the authors call for further search for the criteria of pesticide classification and draw attention to some pesticides, discussing their re-classification into higher classification classes.

Animals↗
PubMedDate not supplied

Development of a method of analysis for 46 pesticides in fruits and vegetables by supercritical fluid extraction and gas chromatography/ion trap mass spectrometry.

A multiresidue method using supercritical fluid extraction (SFE) and gas chromatography/ion trap mass spectrometry (GC/ITMS) was developed for analysis of 46 pesticides in fruits and vegetables. The SFE procedure used 2 commercial instruments that trapped the extracts on solid-phase material. Silica gel chemically bound to octadecylsilane (ODS) collected the extracted pesticides efficiently, and elution of the trap with acetonitrile gave high recoveries. Extracts thus obtained were sufficiently clean for subsequent GC/ITMS analysis. The SFE conditions were 320 atm and 60 degrees C (0.85 g/mL CO2 density) and 1.6 mL/min CO2 flow rate for 6 extraction vessel volumes. Trapping on 1 mL ODS occurred at 10 degrees C, and a 0.4 mL/min flow rate of acetonitrile at 40 degrees-50 degrees C was used to elute the pesticides. Quantitative and qualitative analyses of the 46 pesticides were performed simultaneously by GC/ITMS. Studies of fortified samples gave > 80% recoveries for 39 pesticides, and recoveries of > 50% for the other pesticides, except methamidophos and omethoate. Grapes, carrots, potatoes, and broccoli were used as samples during method development, and a blind experiment involving incurred and fortified samples was used to test the approach. Results of the blind study compared satisfactorily with results from 7 laboratories using traditional GC detectors and solvent-based extractions.

Fruit↗
PubMedDate not supplied

Determination of pesticides in indoor air and dust.

Improved analytical and sampling methods were developed for the multiresidue determination of pesticides in indoor air. Air analysis consists of adsorption of the pesticides in 1 m(3) of air onto Tenax TA via an air sampling pump, desorption with acetone and determination and quantitation by gas chromatography/mass spectrometry (GC/MS) with chemical ionization on an ion trap mass spectrometer. Limits of detection for the 23 pesticides studied ranged from 0.5 ng/m(3) for chlorpyrifos and diazinon to 30 ng/m(3) for o-phenylphenol (approximately 0.5-30 parts per trillion on a w/w basis). A simple method for the detection of pesticides in dust was also developed. This method involves emptying the contents of a vacuum cleaner bag into a standard household food processor and extracting 1 g homogenized dust with acetone before GC/MS. Limits of detection were 25-100 ppb because of interferences by common household chemicals. However, pesticide concentrations were higher in dust than in air, therefore, analysis of dust is a better indicator of indoor pesticide exposure.

Adsorption↗
PubMed1996

Assessment of human exposure to pesticides in greenhouses and effectiveness of personal protective devices.

The exposure to pesticides in a group of workers growing vegetables in greenhouses in farms near Rimini in Italy was evaluated. The pesticides used were organophosphorus compounds, organochlorine compounds, carbamates, pyrethroids, amide and anilide derivatives. Measurements were carried out in seven greenhouses randomly selected. The environment was free of atmospheric agents which could have influenced the pesticide concentrations in the indoor air. Two types of chemical sampling were performed: environmental and personal. The latter was done in the liquid for washing hands and by means of pads applied directly to the worker's skin and to the clothes. The aim of the determination of airborne pesticide concentrations was to evaluate mean environmental exposure to pesticides in the sprayed areas. The sampling went on from a fixed point during the entire spraying period. The aim of individual sampling was to determine the active ingredients as contaminants. The values obtained showed a risk of exposure for the greenhouse personnel working without using personal protective devices (masks, gloves and waterproof clothes), considering that pesticides could be absorbed through the skin in between the spraying intervals.

Agricultural Workers' Diseases↗
PubMedDate not supplied

Extraction and cleanup of organochlorine and organophosphorus pesticide residues in fats by supercritical fluid techniques.

A supercritical fluid extraction and cleanup procedure was developed for separating organochlorine and organophosphorus pesticides from fats. Supercritical carbon dioxide modified with 3% (v/v) acetonitrile was used to extract the pesticides at 60 degrees C and separate the pesticides from the fats at 4000 psi and 95 degrees C on an in-line, C1 silica-based column. The extraction and cleanup procedure gave good recoveries for 43 of 62 nonpolar to moderately polar organochlorine and organophosphorus pesticides from fats, whereas 49 were recovered through conventional Florisil column cleanup before quantitation. This procedure can extract and clean up pesticide residues from 0.65 g animal-based fat and 1.0 g oils. Coeluted residues in the pesticide fraction ranged from 2.5 mg for butterfat to 0.8 mg for corn oil. Results for samples analyzed with this integrated extraction cleanup procedure were reproducible and comparable with results obtained with the current Total Diet Study methodology.

Chromatography, Gas↗
PubMedDate not supplied

Evaluation of organophosphorus pesticide residues in citrus fruits from the Valencian community (Spain).

Approximately 200 citrus samples from markets of the Valencian Community (Spain) were analyzed to establish their residue levels in 12 organophosphorus pesticide residues during the 1994-1995 campaign. The organophosphorus pesticides carbophenothion, chlorpyriphos, chlorfenvinphos, diazinon, ethion, fenitrothion, malathion, methidation, methylparathion, phosmet, quinalphos, and tetradifon were simultaneously extracted by matrix solid-phase dispersion and determined by gas chromatography-mass spectrometry using selected ion monitoring mode. A total of 32.25% contained pesticide residues and 6.9% exceeded the European Union Maximum Residue Levels (MRLs). The pesticides found in the samples with residues above MRLs were carbophenothion, ethion, methidathion, and methyl parathion. Lower level residues of these and the other pesticides studied (except diazinon) were frequently found. The estimated daily intake of the 12 organophosphorus pesticide residues during the studied period was 4.87 x 10(-4) mg/kg body weight/day. This value is lower than the provisional tolerances dairy intakes proposed by the Food and Agriculture Organization and the World Health Organization.

Chromatography, Gas↗
PubMed1998

Clinical, cytogenetic and toxicological studies in rural workers exposed to pesticides in Botucatu, São Paulo, Brazil.

Pesticides can cause gene mutations and chromosomal aberrations in exposed individuals. We have investigated 24 workers exposed to pesticides. Clinical examinations and cytogenetic and toxicological tests were performed. Ten non-exposed individuals were used as controls. Toxicological dosages of copper, zinc and manganese (metals found in some pesticides), hepatic enzyme dosage (GOT, GPT, AR) and acetylcholinesterase activity were performed in 16 workers and 8 controls. In the exposed workers, the most relevant clinical symptoms were poor digestion with fullness sensation after meals, irritated eyes, headache and fasciculations. The exposed group showed significantly lower manganese dosage and acetylcholinesterase activity, and significantly higher levels of alkaline phosphatase. Cytogenetic studies showed significantly higher chromosomal aberrations in the exposed group compared to the control group. Although the workers used protection against the pesticide's fog, the results revealed that the workers were contaminated with the pesticides. Therefore, the cytogenetic, toxicological studies with clinical examination are necessary for monitoring workers who are exposed to pesticides in any situation.

Adult↗
PubMed1999

Sperm aneuploidy among Chinese pesticide factory workers: scoring by the FISH method.

BACKGROUND: A study of the prevalence of sperm aneuploidy among pesticide factory workers was conducted in Anhui, China. METHODS: We recruited 75 men: 32 subjects from a large pesticide-manufacturing plant and 43 subjects from a nearby textile factory free of pesticide exposure. Each subject met the following criteria: age of 20-40 years; continuous work in the plant for 3 months prior to the study, no congenital anomalies or acquired disease of the external genitalia and no history of recent febrile illness or mumps. Within one hour after collection from each subject, semen was evaluated in terms of several parameters and smear slides were prepared. RESULTS: Exposure assessment revealed that workers in the pesticide plant were exposed to ethyl parathion or methamidophos, each of which is a potent organophosphate pesticide, at a median level of 0.02 mg/m3 (8-hour time weighted average as measured by personal pump) while workers in the control plant had no such occupational exposure. Twenty-nine semen slides (13 from the exposed group and 16 from the unexposed group) were randomly chosen for aneuploidy scoring by the three-color fluorescence in situ hybridization (FISH) method with scorers being unaware of exposure status. Median semen parameters were as follows for exposed (and unexposed) men: abstinence period, 3 days (4 days); sperm concentration, 52.8x10(6)/ml (53.1x10(6)/ml); proportion of sperm with normal motility, 50.5% (61.3%); and proportion of sperm with normal morphology, 59% (61.5%). The specific chromosome abnormalities of interest were disomy for chromosome 18 and the three different types of sex chromosome disomy (i.e. XX, XY, YY disomy). The crude proportion of all aneuploidy combined was 0.30% and 0.19% for sperm from exposed and unexposed men, respectively. Poisson regression with overdispersion adjustment yielded significantly different crude risks of aneuploidy - 3.03 and 1.94 per 1,000 sperm from exposed and unexposed men, respectively - giving a rate ratio of 1.56 (95% CI, 1.06-2.31). The regression coefficients remained statistically significant after adjustment for inter-technician variability giving a rate ratio of 1.51 (95% CI, 1. 04-2.20). CONCLUSIONS: We conclude that occupational exposure to organophosphate pesticides moderately increases the prevalence of sperm aneuploidy.

Adult↗
PubMed2003

Pancreatic cancer mortality and organochlorine pesticide exposure in California, 1989-1996.

BACKGROUND: Occupational studies have suggested a possible link between organochlorine pesticides and the occurrence of pancreatic cancers. California maintains a death file and a pesticide reporting system that allows examination of this relationship for residents of high use areas. METHODS: We employed a mortality odds ratio design to compare deaths from pancreatic cancer (1989-1996) with a random sample of non-cancer deaths. Using pesticide data for three agricultural counties, we classified 102 ZIP codes in quartiles of pesticide usage for 1972-1989. Using logistic regression we estimated the effect of pesticide applications by ZIP code controlling for possible confounders. RESULTS: Among long-term residents, pancreatic cancer mortality was elevated for those living in ZIP codes with the highest use of four pesticides: 1,3-dichloropropene (1,3-d), captafol, pentachloronitrobenzene (PCNB), and dieldrin. No dose-response relationship was observed. CONCLUSIONS: Our study suggests increased pancreatic cancer mortality among long-term residents in areas of high application rates of 1,3-d (an EPA-classified probable human carcinogen), captafol, pentacholoronitrobenzene (PCNB), and dieldrin.

Age Factors↗
PubMed1998

Rapid estimation of octanol-water partition coefficients of pesticides by micellar electrokinetic chromatography.

Micellar electrokinetic chromatography (MEKC) was evaluated as a new technique for the rapid estimation of octanol-water partition coefficient (logKow). Retention measurements for more than 40 reference pesticides with varied structural characteristics and hydrophobicity were carried out in two MEKC systems, based on sodium dodecyl sulfate (SDS) and sodium cholate (SC), respectively. To enable an accurate determination of capacity factors in the SC-MEKC system, cypermethrin (a synthetic pyrethroid insecticide) was utilized instead of Sudan III as the SC micelle tracer, since a few highly hydrophobic pesticides were found to elute after Sudan III. The linear correlation between logarithmic capacity factor (logk') and logKow in the two systems was examined. It was found that, under the typical buffer condition (10 mM sodium phosphate with 60 mM surfactant, pH 7.0), the SDS-MEKC system provided a somewhat wider dynamic range for hydrophobicity (logKow from -1.0 to 4.5). However, the correlation of logk' with logKow was not very high when all the reference pesticides were included in one single calibration set. For the SC-MEKC system, the dynamic range for logKow was in the range of 1.0-5.5, and a good linear correlation existed between logk' and logKow, even when all reference pesticides were incorporated into a single calibration group. By comparing the regression line of the reference pesticides with that of a group of simple aromatic derivatives, it was discovered that molecular size and functionality posed a less significant effect on the measurement of logKow in the SC-MEKC system than in the SDS-MEKC system. Thus, SC-MEKC shall be the system of choice for the estimation of logKow. The typical error on logKow determination using the current MEKC technique was within 0.5 units, suggesting that MEKC can be a valuable complement to reversed phase high performance liquid chromatography (RP-HPLC) for the indirect determination of logKow. Besides maintaining all the advantages of the HPLC approach, the MEKC technique showed some unique benefits, such as better inter-column reproducibility, higher throughput, and less handling of toxic pesticides and solvents.

Chromatography↗
PubMed2005

Behavioral and sex ratio modification of Japanese medaka (Oryzias latipes) in response to environmentally relevant mixtures of three pesticides.

We exposed Japanese medaka (Oryzias latipes) to environmentally relevant concentrations of azinphos-methyl, chlorothalonil, endosulfan, and mixtures of all three to determine if combinations of these pesticides result in additive, less-than-additive, or more-than-additive effects. Medaka were exposed from fertilization until 7 days posthatching, and end points included survival, time to hatch, size at 7 days posthatching, activity level (as measured by distance swam) and foraging ability at 3 weeks posthatching, and adult size, liver size, and sex ratio at 5 months posthatching. Although exposure to individual pesticides or pesticide mixtures did not affect survival, hatching time, or foraging ability, fry exposed to azinphos-methyl were significantly smaller at 1 week of age, and those exposed to chlorothalonil and a combination of the chemicals showed reduced activity. Adult sex ratios were biased toward females in all groups exposed to pesticides, with those exposed to azinphos-methyl, chlorothalonil, and the pesticide mixture departing significantly from an even sex ratio. There was no evidence of additive or synergistic effects of pesticide mixtures.

Animals↗