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PubMed1993

Family pesticide use and childhood brain cancer.

The relationship between family pesticide use and childhood brain cancer was examined in a case-control study. Telephone interviews were conducted from June 1989 through March 1990 with the natural mothers of 45 childhood brain cancer cases, 85 friend controls, and 108 cancer controls. In comparisons to friend controls, significant positive associations were observed for use of pesticides to control nuisance pests in the home, no-pest-strips in the home, pesticides to control termites, Kwell shampoo, flea collars on pets, diazinon in the garden or orchard, and herbicides to control weeds in the yard. In comparisons to cancer controls, significant positive associations were observed for use of pesticide bombs in the home, pesticides to control termites, flea collars on pets, insecticides in the garden or orchard, carbaryl in the garden or orchard, and herbicides to control weeds in the yard. In general, positive associations in comparisons to one control group were supported by elevated odds ratios in comparisons to the other control group. Several potentially important associations were identified in this study. However, small sample sizes, potential recall bias, multiple comparisons, and lack of detailed exposure verification require further research to confirm these findings.

Brain Neoplasms↗

PubMed1994

Survey of pesticides used in the control of ectoparasites on farm animals in Ghana.

A study to identify the various types of pesticides used on farm animals in Ghana for the control of ectoparasites was conducted in 1989. Eleven organisations involved with pesticide use were questioned. Thirty organised farms and 110 kraals distributed throughout the 10 regions of Ghana were visited. Twenty different pesticides were in use. Of these 45% were organophosphates, 30% were synthetic pyrethroids, 15% were carbamates and 10% organochlorines. The most widely distributed and used pesticide was an organochlorine (lindane), which accounted for 35% of those used on farms and 85% used by herdsmen. The most popular mode of application was by hand dressing. No withdrawal periods before slaughter or sale of milk for consumption were practised. The implications of these findings in the light of possible emergence of pesticide resistance and health hazards are discussed.

Animals↗

PubMed2004

Photodegradation and volatility of pesticides: chamber experiments.

BACKGROUND AND OBJECTIVES: Among the factors affecting the environmental fate of surface-applied pesticides several biological as well as abiotic factors, such as volatilization and photochemical transformations are of particular interest. Whereas reliable measurement methods and models for estimating direct photodegradation are already available for the compartments of water and atmosphere and individual subprocesses have already been described in detail, there is still a need for further elucidation concerning the key processes of heterogeneous photodegradation of environmental chemicals on surfaces. METHODS: In order to systematically examine the direct and indirect photodegradation of 14C-labeled pesticides on various surfaces and their volatilization behavior, a new laboratory device ('photovolatility chamber') was designed according to US EPA Guideline 161-3. Model experiments under controlled conditions were conducted investigating the impact of different surfaces, i.e. glass, soil dust and radish plants, and environmental factors, i.e. irradiation and atmospheric ozone (O3), on the photodegradation and volatilization of surface-deposited [phenyl-UL-14C]parathion-methyl (PM). RESULTS AND DISCUSSION: Depending on the experimental conditions, parathion-methyl was converted to paraoxon-methyl, 4-nitrophenol, unknown polar products and 14CO2. With respect to the direct photodegradation of PM (experiments without O3), the major products were polar compounds and 14CO2, due to the rapid photochemical mineralization of 4-nitrophenol to 14CO2. Paraoxon-methyl and 4-nitrophenol formation was mainly mediated by the combination of light, O3, and *OH radicals. In radish experiments PM photodegradation was presumably located in the cuticle compartment, which exhibited a sensitized photodegradation, as more unknown products were yielded compared to the glass and soil dust experiments. This could be explained by intensifying the inherent PM degradation in the dark with the same product spectrum. Due to photochemical product formation, which is an antagonistic process to the volatilization of parent compound, the volatilization of unaltered parathion-methyl from each surface generally decreased in the presence of light, particularly in combination with increasing O3 concentrations and *OH radical production rates. CONCLUSION: First results demonstrated that the photovolatility chamber provides a special tool for the systematic evaluation of (a) photodegradation of surface-located pesticide residues, i.e. measuring qualitative aspects of direct and indirect photodegradation together with relative photodegradation rates, and (b) volatilization of pesticides on surfaces by including and optionally varying relevant parameters such as light, atmospheric O3 concentration, surface temperature, air temperature, air flow rate. OUTLOOK: The experimental facility represents an important complement to lysimeter and field studies, in particular for experiments on the volatilization of pesticides using the wind tunnel system. With the photovolatility chamber special experiments on photodegradation, volatilization and plant uptake can be conducted to study key processes in more detail and this will lead to a better understanding of the effects of certain environmental processes on the fate of released agrochemicals contributing to an improved risk assessment.

Guidelines as Topic↗

PubMed1998

The use of dogs as second species in regulatory testing of pesticides. I. Interspecies comparison.

The relevance of studies in dogs on regulatory testing of pesticides was examined retrospectively using data of 216 pesticides (acaricides, fungicides, growth regulators and hormones, herbicides, insecticides, molluscicides, nematicides, rodenticides, synergists for insecticides) submitted for regulatory purposes during the past 40 years to the Federal Institute of Health Protection of Consumers and Veterinary Medicine (BgVV), the competent national authority in Germany. At first the relevance of the no-observed-effect levels (NOEL) for safety assessment was evaluated for each chemical in 4-week (subacute), 13-week (subchronic) and 52/104-week (chronic) toxicity studies carried out on dogs, rats and mice. After subchronic and chronic application of fungicides the sensitivity of rats and dogs to the toxic chemicals was quite similar. However, the dog was generally a more sensitive species to toxic effects of insecticides than rat and mouse. On the other hand the NOEL was lower in the rat than the dog in chronic studies on herbicides. When the lowest-observed-effect level (LOEL) was evaluated in animal species, the dog was the most sensitive in approximately 15% of the studies. Mice were found to be the most sensitive species only in approximately 1% of the studies on 216 pesticides. Comparison of organ specific toxicity at the LOEL in subacute studies on fungicides and herbicides revealed a poor correlation of target-specific organ toxicity across species. However, in the subchronic and chronic studies (13 and 52/104 weeks) no significant differences in species-specific organ toxicity were observed in the three species rat, mouse and dog. The only exception were haematoxic effects in chronic studies on herbicides, which were more frequent in dogs (40%) than in rats and mice (20%). The results support the established concept that studies on dogs and rats are important for the safety assessment of pesticides, while studies on mice do not provide further information, except for detection of an oncogenic potential which is a further controversial issue. Further analysis of subacute, subchronic and chronic studies in dogs should reveal if all of the studies are essential for safety assessment of pesticides.

Animals↗

PubMed2003

Rapid pesticide analysis, in post-harvest plants used as animal feed, by low-pressure gas chromatography-tandem mass spectrometry.

A wide range of pesticides used to control pests in vegetables have been determined in agricultural plant waste from beans, watermelons, and melons grown in greenhouses located in a predominantly agricultural area in Southeast Spain (Almería). Analysis of the pesticides was carried out by low-pressure gas chromatography (LP-GC) with mass spectrometry in tandem (MS-MS) mode, after extraction of the lyophilized samples with dichloromethane. The influence of the sample matrix on the analysis was avoided by use of matrix-matched standards. Linearity, detection limit ( LOD), quantitation limit ( LOQ), recovery, and precision for each pesticide were calculated. The most frequently encountered pesticides were endosulfan (>73% of the analyzed samples) and buprofezin (>55% of the samples), followed by cypermethrin, pirimifos-methyl, bifentrin, and chlorpyrifos (>30% of the samples). The pesticide found at the highest concentration level was endosulfan (223.33 mg kg(-1)) in a watermelon sample.

Animal Feed↗

PubMed2005

2-D PAGE analysis of pesticide-induced stress proteins of E. coli.

Logarithmically growing batch cultures of Escherichia coli were exposed to sublethal concentrations of pyrethroid and carbamate pesticides of four different technical grades. This induced 17-20 stress proteins, as observed using two-dimensional polyacrylamide gel electrophoresis. An E. coli culture growing exponentially in Luria Bertani medium (cell density approximately 2.3x10(9) cells/ml) was exposed to predetermined sublethal doses of individual pesticides. The cells were harvested after 30 minutes of induction and the stress response was developed in fresh LB medium for three hours under the same growth conditions. Cell pellets were obtained and stored in sonication buffer. Two-dimensional polyacrylamide gel electrophoresis was performed to resolve the proteins. Visualization of the protein spots by rapid silver staining showed 17-20 stress proteins which were absent in the standard protein profile of E. coli. On average 29% of these stress proteins were unique to the pollutant, while the remaining stress proteins overlapped with those of other pesticides. The iso-electric points (PIs) and molecular weights of the proteins were determined by comparing with protein markers with known PIs and molecular weights. Furthermore, upon comparing the pesticide-induced proteins within the same class and between the two different classes (pyrethroid and carbamate), it was apparent that the general nature of the stress remained the same throughout, which indirectly proved that the gene or set of genes responsible for stress expression are also the same, irrespective of the chemical nature of the substituents of the pesticides.

Electrophoresis, Gel, Two-Dimensional↗

PubMed2007

Use of chemometric and geostatistical methods to evaluate pesticide pollution in the irrigation and drainage channels of the Ebro river delta during the rice-growing season.

Data sets obtained from quantitative analysis of seventeen pesticides in water samples from a network of irrigation and drainage channels in the Ebro river delta (Catalonia, NE Spain) have been analysed by chemometric and geostatistical methods. Samples were taken at fourteen locations during the main rice-growing season, from May to August 2005. Principal-component analysis enabled investigation of the spatial and temporal distribution of the main pollution patterns caused by application of pesticides in the region under study. A first pesticide-contamination pattern from the Ebro river was differentiated from a second more specific pattern from the water-drainage channels of the delta, collected from the rice fields. The seasonal peak in this more specific rice pesticide source was observed in July. Coupling the results from chemometric data analysis with use of geostatistical methods was shown to be a useful procedure for discovery of the most significant spatial and monthly variations of the main pesticide-contamination patterns, taking into account the particular geographical structure of the area under study.

Oryza↗

PubMed2003

Analysis of pesticides in water and sediment under different storage conditions using gas chromatography.

This paper describes the process of testing a simple low-solvent method for simultaneously extracting five classes of pesticides (triazines, organophosphates, organochlorines, pyrethroids, and carbamates) from reconstituted water and sediment. This method uses techniques available in most laboratories, namely solid phase extraction (SPE) and sonication in combination with gas chromatography. The recoveries of pesticides ranged from 60 to 120% with the exception of carbaryl, dicofol, and methoxychlor that had higher recoveries. Methods were further tested with pond water and soil samples. The recoveries of pesticides from soil were comparable with those from sediments, while in pond water, recoveries of the organochlorines exceeded 100%. A matrix enhancement effect was suspected to be the cause for the observed elevated recoveries. In order to determine time range and conditions in which the samples can be stored without significant losses, recoveries of pesticides in water and sediment were monitored for 28 days. Water samples were most stable when extracted immediately and stored in SPEs in the freezer. These samples remained stable for up to six weeks in the freezer, whereas sediment samples were stored for a month without a significant decrease in pesticide concentrations.

Chromatography, Gas↗

PubMed2005

Statistical model of pesticide penetration through woven work clothing fabrics.

Statistical models estimating the level of protection and thermal comfort performance of woven fabrics were developed using simple fabric and liquid parameters. Eighteen woven fabrics were evaluated against three pesticide mixtures of atrazine and pendimethalin at different concentrations. Using three mixtures that represent a range of both surface tension and viscosity, percentages of pesticide penetration are measured, along with fabric thickness, fabric cover factor, yarn twist factor, yarn packing factor, solid volume fraction, wicking height, and air permeability. Statistical analyses are performed to examine the relationship between liquid/fabric parameters and pesticide penetration. Statistical analyses show that fabric cover factor, yarn twist factor, viscosity of pesticide mixture, critical surface tension of solid, and wicking height are significant parameters affecting pesticide penetration. For this purpose, cover factor and twist factor are better parameters in describing the geometry of woven fabrics than solid volume fraction. Modeling of comfort performance of woven fabric based on simple textile parameters shows that the combination of fabric thickness, cover factor, yarn twist factor and yarn packing factor can be used to estimate air permeability of woven fabric. These findings could be used for developing selection charts or tools as guidelines for the selection of personal protective equipment for use in hot, humid environments.

Materials Testing↗

PubMed2006

Monitoring of nutrients, pesticides, and metals in waters, sediments, and fish of a wetland.

Wetland areas are of extraordinary importance for the conservation of wildlife. The Aiguamolls de l'Empordà Natural Park, located in Girona (northeast Spain), is one of the few areas in Europe acting as a way station for migratory birds. The natural park is made up of a brackish water reserve and a fresh water reserve. Agriculture and tourism, which are concentrated especially around coastal population centers, are the main activities in this area and result in the release into the environment of nutrients, pesticides, and heavy metals. This article aims to investigate the presence of nutrients, selected pesticides (organochlorine compounds, permethrin and triazines) and metals (Cr, Cu, Cd, Ni and Pb) in water, sediments, and fish samples. In the case of water, seasonal variations in levels of contamination were also monitored. Comparison was made of the fresh and brackish water reserves and concentration factors for metals and pesticides in sediment were determined. We conclude that the most significant sources of contamination in the natural park are from the entry of pesticides and nutrients into surface waters and sediments as a result of the intensive farming activity of the surrounding areas. The pesticides with the greatest presence were found to be lindane, heptachlor epoxide, permethrin, and atrazine. Among the metals analyzed, Cu and Cr presented the highest concentrations in surface waters and sediments.

Animals↗

PubMed1997

Effect of the nature of exogenous organic matter on pesticide sorption by the soil.

A study was carried out on the sorption of two sparingly water-soluble pesticides (diazinon and linuron) by a sandy loam soil modified with different exogenous organic materials (EOMs) containing humic-like substances: city refuse compost (CRC), peat (P), commercial "humic" acid (HA), liquid "humic" acid (LHA), and two (nonhumic) model compounds (surfactants), tetradecyltrimethylammonium bromide (TDTMA) and sodium dodecyl sulphate (SDS), before and after 2- and 8-month incubation periods with the soil. In all cases, the isotherms fitted the Freundlich sorption equation (x/m = KCen), generally with r2 values greater than 0.99. The value of the sorption constant K for the natural soil was 8.81 for diazinon and 2.29 for linuron. These values increased significantly for EOM modified soils with respect to natural soil, with the exception of the samples modified with SDS and LHA, in which cases they decreased, possibly due to the micellar properties of these compounds. Incubation of EOMs with soil increased their sorption capacity: the Koc values were increased proportionally to the incubation time for both pesticides and for all treatments carried out. Accordingly, the sorption capacity of hydrophobic pesticides increases with the degree of evolution in the soil of EOMs with "humic"-type compounds, possibly due, among other causes, to the increase in the EOMs' colloidal properties and the modifications occurring in the hydrophobic-hydrophilic characteristics of the soil surfaces. The main conclusion is that application to the soil of carbon-rich wastes, especially those with a high degree of maturity, may offer an important strategy for reducing pesticide leaching and for eliminating pesticide residues from soil with the use of anionic surfactants.

Adsorption↗

PubMed2005

Growth and denitrifying activity of Xanthobacter autotrophicus CECT 7064 in the presence of selected pesticides.

The effects of the application of nine pesticides used commonly in agriculture (aldrin, lindane, dimetoate, methylparathion, methidation, atrazine, simazine, captan and diflubenzuron) on growth, CO2 production, denitrifying activity [as nitrous oxide (N2O) released] and nitrite accumulation in the culture medium by Xanthobacter autotrophicus strain CECT 7064 (Spanish Type Culture Collection) (a micro-organism isolated from a submerged fixed-film) were studied. The herbicide atrazine and the insecticide dimetoate totally inhibited growth and biological activity of X. autotrophicus at 10 mg l(-1), while the rest of the tested pesticides delayed the growth of strain CECT 7064 but did not drastically affect the bacterial growth after 96 h of culture. The denitrifying activity of X. autotrophicus was negatively affected by the pesticides application with the exception of fungicide captan. The release of N2O was strongly inhibited by several pesticides (aldrin, lindane, methylparathion, methidation and diflubenzuron), while dimetoate, atrazine and simazine inhibited totally the denitrifying activity of the strain. The effects of the pesticides on denitrifying submerged fixed-film reactor are discussed.

Carbon Dioxide↗

PubMed2006

Do pesticides cause childhood cancer?

OBJECTIVES: Epidemiological studies have reported associations between childhood cancer and either parental or child exposure to pesticides. Reviews have been published in 1997 and 1998, where the evidence was found suggestive but not conclusive. An update of the current state of knowledge is warranted. METHODS: A literature search has been conducted to identify and evaluate new research results on this topic issued between 1998 and 2004. RESULTS: Eighteen new studies have been identified for this review. Collectively, the studies suggest an increase in the risk of different cancer types associated with exposure to pesticides. However, the evidence is conflicting with regard to cancer types as well as to causative factors across studies. The major shortcomings concern exposure assessment, where, e.g., "farming" is treated equal to "exposure to pesticides," disregarding other possible exposures, e.g., to biological or infectious agents, and hitherto unidentified lifestyle factors. Also, many exposure questionnaires used in case-control studies are based on broad and sometimes implausible categories. In most studies exposures were categorized as "ever vs. never," with no regard for exposure intensity or duration. CONCLUSIONS: The available literature does not allow firm conclusions with regard to pesticides and any type of childhood cancer. Investing in the acquisition and critical review of exposure information appears to be the crucial step for causal assessment in future research. However, focusing on the presence of pesticides, and not asking the question why they were used, might mask relevant associations to other causative agents.

Adolescent↗

PubMed2002

Aerial short-range dispersion of volatilized pesticides from an area source.

Owing to legal provisions, pesticides have to be applied in such a way that there is no unacceptable influence on human health and the environment at nearby non-target areas. In order to quantify their concentration over and downwind of agricultural target plots of 0.5-1 ha, covered by winter wheat and winter barely, the pesticides lindane, parathion and pirimicarb were applied. Over these plots the post-application volatilization rates of the pesticides were estimated indirectly from vertical concentration, wind and temperature profile measurements using the aerodynamic gradient technique. Philip's advection model was applied to take non-favourable fetch conditions into account. In addition, at a height of 1.6 m downwind of the area source, measurements of the horizontal concentration profile were made up to a distance of about 250 m at roughly 50-m intervals. The monitoring started immediately after spraying in the morning and continued for about 8-10 h, thus providing a worst-case situation because volatilization, and therefore pesticide concentration in the atmospheric surface layer, is then strongest. The concentration of the airborne pesticides over the downwind non-target area was also calculated by Philip's advection model. By using the Nash-Sutcliffe relative-difference measure between observed and calculated concentrations, a goodness-of-fit of 0.97 was obtained over the downwind non-target area, indicating that the Philip model is well suited for dispersion estimates in the near-field range.

Agriculture↗

PubMed2006

Review and meta-analysis of risk estimates for prostate cancer in pesticide manufacturing workers.

PURPOSE: The purpose of the present paper is to review cohort studies that examined the occurrence of prostate cancer in pesticide manufacturing workers in order to undertake a qualitative and quantitative evaluation of the risk as well as to assess the level of epidemiological evidence for each class of chemical compounds. METHODS: Following a systematic literature search, relative risk (RR) estimates for prostate cancer were extracted from 18 studies published between 1984 and 2004. All studies were summarised and evaluated for homogeneity and publication bias. As no significant heterogeneity was detected, combined RR estimators were calculated using a fixed effect model. Meta-analyses were performed both on the whole set of data and for each chemical class separately. RESULTS: The meta-rate ratio estimate for all studies was 1.28 [95% confidence interval (CI) 1.05-1.58]. After stratification by specific chemical class, consistent increases in the risk of prostate cancer were found in all groups but statistical significance was found only for accidental or non-accidental exposure to phenoxy herbicides contaminated with dioxins and furans. There was no obvious indication of publication bias. CONCLUSION: The overall meta-analysis provides additional quantitative evidence consistent with prior reviews focusing on other groups exposed to pesticides (farmers, pesticide applicators). The results again point to occupational exposure to pesticides as a possible risk factor for prostate cancer but the question of causality remains unanswered. Epidemiological evidence did not allow identifying a specific pesticide or chemical class that would be responsible for the increased risk but the strongest evidence comes from workers exposed to phenoxy herbicides possibly in relation with dioxin and/or furan contamination.

Chemical Industry↗

PubMed2006

Risk assessment of organic pesticides pollution in surface water of Hangzhou.

Advances in research on pollution of organic pesticides (OPs) in surface water, pollution survey and risk assessments of organochlorine pesticides (OCPs) and organophosphorus pesticides (OPPs) of surface water in Hangzhou are conducted. Total concentrations of dichloro-diphenyl-trichloroethane (DDT) and hexachloride-benzene (HCH) in surface water were observed to be 0-0.270 microg/L and 0-0.00625 microg/L respectively. DDE, as a metabolite of DDT and many species of OPP(S) were determined in some samples of surface water. Parathion, the main pollutant among OPPs in surface water of Hangzhou, was observed to be 0-0.445 microg/L. Based on these experimental results, health risk assessments on the organic pollution are developed. It is observed that the total risk "R (T)" at present time of surface water in Hangzhou is mainly contributed by organophosphorus pesticides, especially Parathion; HCH and DDT are not the main contaminants; on the contrary, organophosphorous pesticides, especially Parathion, must be of concern at the present time.

China↗

PubMed2006

The contamination levels of organochlorine pesticides in water and sediment samples in Uluabat Lake, Turkey.

The Uluabat Lake is a reservoir of 125 km2 surface area, in the boundaries of Bursa province, Turkey. The results showed that Uluabat Lake was still contaminated by organochlorine pesticides and their residues despite the existence of bans over a long time. Considerable amounts of organochlorine pesticides (HCB, p.p'-DDT, p.p'-DDE, alpha-, beta- and gamma-BHC, Aldrin, Heptachlor epoxide, Endrin, Endosulfan I and II) were detected in water and sediment samples during one-year study in this lake. Samples of water and sediment were collected in different regions, (6 sampling point) of the lake between February 2002 and November 2002. The mean levels of organochlorine pesticides in water and sediments were determined. According to results, it was found that various environs in Uluabat Lake were contaminated by 11 different organochlorine pesticides. Residue analyses showed that higher organochlorine pesticides and their residues were generally more accumulated in the sediment samples.

Agriculture↗

PubMed1992

Supercritical fluid extraction of polychlorinated biphenyls and pesticides from soil. Comparison with other extraction methods.

A comparison is made of supercritical fluid extraction (SFE) with two other techniques widely used for the extraction of polychlorinated biphenyls (PCBs) and organochlorine pesticides in soil. Extraction conditions for the SFE of PCBs and pesticides were first determined. An experimental approach was set up to determine the influence of different extraction parameters such as pressure, extraction time, static and dynamic extraction, restrictor type and collection solvent for off-line SFE. The use of carbon dioxide at 50 degrees C and 20 MPa, 10 min static followed by 20 min dynamic extraction with collection in iso-octane were been found to be the optimum conditions. Two types of soil, with a low and high content of organic carbon, respectively, spiked with 16 PCBs and organochlorine pesticides with a wide range of volatility and polarity at a level of 5 ng/g dry matter, were used as test materials. Conventional solvent extraction gives a good extraction yield for soil with a low content of organic carbon, but for peat soil the recoveries decrease dramatically to 30% for DDE, DDT and PCB 138 and 153. The recoveries with Soxhlet extraction are good, but an extra clean-up step before analysis is necessary. SFE gives good extraction yields for PCBs and organochlorine pesticides, varying between 85 and 105% with a reproducibility of 5% for each component for both types of soil. SFE is a fast, clean and reproducible method for the extraction of PCBs and organochlorine pesticides from these two soil matrices.

Carbon↗