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 415 records · Page 23Linked to original sources
PubMed2001

Chemistry and specifications of pesticides.

This report presents the conclusions of a WHO Expert Committee commissioned to make recommendations on specifications for pesticides used in public health, with a view to promoting the manufacture and use of high-quality products that are both effective against susceptible vectors of disease and acceptable in terms of safety. These specifications serve mainly for purchase and quality-control purposes, but may also be useful for product registration by WHO Member States. The text includes an outline of the objectives and achievements of the WHO Pesticide Evaluation Scheme (WHOPES) and an overview of recent trends in pesticide usage in the various WHO regions. Analytical methods and quality control of pesticides in developing countries are discussed, and the Committee's recommendations for specifications for various types of pesticides are presented. The Committee also considered pesticide containers and packaging, marking and storage, as well as the problems of disposal of unusable pesticides and their containers. Recommendations for continued collaboration between WHO and other organizations are summarized, as are the Committee's more general recommendations for WHO's future work in the area of pesticides. Annexed to the report are the Committee's recommendations for changes to existing specifications and methods, for new pesticides and formulations, and for new methods.

Agrochemicals↗
PubMed2001

[An epidemiological study on pesticide poisoning with mixed preparation].

OBJECTIVE: To investigate the incidence of pesticide poisoning with mixed preparation and risk factors contributing to it. METHODS: Twenty-five administrative villages were studied in three townships of Jiangsu and Shandong Provinces with cluster sampling. The sampled villages were divided into study group (12 villages) and control group (13 villages) with approximately equal number of people each. Pesticide sprayers in the study group applied mixed preparation containing organophosphorous and dimethrin and those in the control group applied single organophosphorous preparation. All the sprayers in sampled villages were interviewed with a same questionnaire about their situation of pesticide spraying during the observation period. Cases of pesticide poisoning were ascertained by seniors physicians in occupational diseases after group discussion. RESULTS: Incidence of pesticide poisoning was higher in 2 179 sprayers of the study group (10.10 %) than that in 2 615 of the control group (2.29%), with a highly statistically difference (chi(2) = 12.46, P < 0.01) and an risk ratio (RR) of 4.45 (95% CI = 1.94 approximately 10.05) adjusted for other risk factors by logistic regression. Other risk factors for pesticide poisoning with mixed preparation were smoking or taking food during spraying, leaking or breakdown of sprayers, without washing their whole body as soon as possible after spraying, poor personal protection, spraying for a long time, spraying by women and spraying pesticide on cotton. CONCLUSIONS: If toxicity of mixed preparation of single pesticide showed a synergistic or additional effect, risk of poisoning by spraying mixed preparation increased. Health education and technical training should be strengthened for pesticide sprayers.

Adult↗
PubMed2001

Assessment of the ability of health care providers to treat and prevent adverse health effects of pesticides in agricultural areas of Tanzania.

A survey of Tanzanian health care providers in agricultural areas was undertaken in 1991-1994 to assess their knowledge of toxic effects of pesticides, experiences and practices, as well as of their needs for appropriate information in order to develop effective strategies for reducing pesticide poisoning. Face-to-face interviews were conducted with 104 physicians, clinical officers and nurses at health care facilities in the coffee and cotton growing areas. Eighty percent of respondents reported to have seen one and nine of them two to four cases of pesticide poisoning in the preceding three months. A significantly higher annual number of poisonings were observed in coffee than in cotton area (GM 0.5 vs 0.1). Also the number of cases registered in hospitals was considerably higher than that in the out-patient health care (GM 1.7 vs 0.2). Pesticide poisoning was regarded as a major problem in the community by 63% of health care providers, including 77% of hospital staff. One third of health care providers thought that a certain percent of pesticide poisoning cases remain unrecognized, and that this percentage is higher in cotton than in coffee growing areas. The respiratory tract was the major route for pesticide to enter the human body; this was followed by gastrointestinal tract, skin, and eyes. Only one percent of the respondents could identify the groups of pesticides (organophosphate vs organochlorine) mostly used in the study areas. The survey indicated that training of hospital staff in toxicity of pesticide exposure is an important task and a prerequisite for efficient recognition, diagnosis and treatment of pesticide poisoning cases in Tanzania.

Adult↗
PubMedDate not supplied

Comparison of five extraction methods for determination of incurred and added pesticides in dietary composites.

The National Exposure Research Laboratory of the U.S. Environmental Protection Agency conducts research to measure exposure of individuals to chemical pollutants through the diet. In support of this research, methods are being evaluated for the determination of pesticides in dietary composite samples. In the present study, Soxhlet, blender, microwave-assisted, pressurized fluid, and supercritical fluid extraction methods were compared for the determination of incurred and added pesticides in 4 dietary composites, which varied in fat and water content. Incurred pesticides were chlorothalonil, chlorpyrifos, DDE, dicloran, dieldrin, endosulfan I, malathion, cis- and trans-permethrin, and trifluralin. Added pesticides were alpha- and gamma-chlordane, hexachlorobenzene, and fonofos. Concentrations of the individual pesticides were between 0.2 and 20 ng/g composite. All 5 methods tested could extract pesticides from dietary composites. Most incurred pesticides were recovered from the dietary composites within the range of 59-140% of expected values. Recoveries of added pesticides were between 60 and 130%. Microwave-assisted extraction led to significantly higher concentrations of 7 pesticides. Blender extraction yielded significantly higher concentrations of chlorothalonil and fonofos. Water content was a significant factor in the recovery of chlorothalonil, and fat content was a significant factor in the recovery of fonofos. In designing an exposure study, the selection of the extraction method would be determined by number of samples to be extracted, analyte stability, and cost.

Diet↗
PubMed2003

[Study on of dietary pesticide residues in Chinese residents].

OBJECTIVES: To investigate the change of pesticide residues in Chinese dietary through analysis on results of the pesticide residues in the Chinese total diet study carried out the first in 1990. METHODS: Organochlorine, such as HCH and DDT of 9 groups and 15 organophosphorus pesticide residues of 3 groups in four regions of China were determined by gas chromatography-electron capture detector (GC-ECD) and gas chromatography-flame photometric detector (GC-FPD) respectively. According to the amount of pesticide residues in various foods and the amount of food consumption in different areas, we calculated the amount of dietary intake of pesticide residues, then compared with the acceptable daily intake (ADI) or provisional tolerable daily intake (PTDI). The contaminated samples were validated by gas chromatography-mass spectrometry (GC-MS). RESULTS: Results showed that the total dietary daily intake of HCH per person was decreasing from 5.04 micro g in 1990 to 3.11 micro g in 2000, where as the total dietary daily intake of DDT per person was decreasing from 20.47 micro g in 1990 to 2.15 micro g in 2000. The result was less than 1 percent difference of PTDI (0.01 mg/kg bw) established by the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) in 2000. Compared to the results in 1990, the intake of HCH from animal foods increased a little, due to the contaminated of aquatic products by Lindan in the second Southern region and the first Northern region. None of the organophosphorous pesticide residues analyzed were detected in cereals, vegetables and fruits. CONCLUSION: The intake level of pesticide residues in Chinese dietary in 2000 was considered to be low, and the abuse of organophosphorous pesticide seemed to be under effective control.

Animals↗
PubMed2004

[A survey of emergency treatment of pesticides poisoning in comprehensive hospitals].

OBJECTIVE: To seek the characteristics of pesticide poisoning in emergency departments. METHODS: Twenty-five hospitals were selected. Among them, they were 14 province or city level and 11 county level. The object of study was the patients with pesticide poisoning who were first visit to a doctor (including transfer to the above emergency departments of hospitals) from July 1, 2001 to June 30, 2002. RESULTS: There were 2 261 cases of pesticide poisoning that ranked third place of total acute poisoning cases at the same period. Gender ratio was 1 male to 1.47 female. Among 1 618 patients who first visited to emergency departments (excluding transfer), 43.9% were by emergency ambulance. 68.3% of total cases were caused by intentional exposure to pesticides, of which female accounted for 75.8%. Young people aged 15 to approximately 34 years accounted for 47.5% of all cases. Children (0 to approximately 14 years) also had relatively high pesticide poisoning rates, particularly an accident pesticide poisoning for 1- to approximately 4-year-old children accounted for 65.9% of total acute poisoning in the age group. 98.2% of all cases needed urgent medical treatment, and 52.4% were hospitalized. The leading occupation of patients was farmers followed by housekeepers, students and preschoolers. Insecticides poisoning accounted for 60.1% of all pesticides. The fatality rate in emergency department was 3.9%. 60.8% case was collected from county hospital. Pesticide poisoning rank first place of total acute poisoning cases in county hospital. CONCLUSION: A safety education of Knowledge Attitude Practice (KAP) is an effective measure for preventing pesticide poisoning.

Adolescent↗
PubMed2005

Effects of organophosphorous pesticides used in china on various mammalian cells.

Organophosphorous pesticides are currently widely used in China to help boost agricultural production. However, these pesticides pose various threats to organisms, including humans, and are thus a cause of concern. Five organophosphorous pesticides, monocrotophos, omethoate, parathion-methyl, phoxim and dichlorvos, were examined for their effects on mammalian cell lines to determine their potential impact on physiological functions in vivo. Results show an increased proliferation of MCF-7 cells treated with 0.2 microM monocrotophos or 0.4 microM omethoate, suggesting that these compounds can induce breast cancer cell proliferation at relatively low concentrations. Murine primary spleen cells markedly decreased in number starting at a pesticide concentration of 0.01 microM; no cytotoxicity was observed below 0.001 microM. BALB/c3T3 murine fibroblasts treated with 0.25 microM monocrotophos showed enhanced DNA synthesis, while those treated with the other pesticides showed results similar to that of the control. The different pesticides reduced the acetylcholinesterase (AChE) activity of the rat neuronal cell line PC12 in a dose-dependent manner up to 100 microM. Parathion-methyl and phoxim showed acute toxicity at 0.01 microM. Finally, phoxim and parathion-methyl significantly reduced the transepithelial electrical resistance (TEER) of human intestinal Caco-2 cells, indicating that these pesticides can disrupt the tight-junction permeability of cell monolayers. These in vitro assays, which are rapid, reproducible, simple and inexpensive, clearly show the effects of organophosphorous pesticides on mammalian cells and suggest the potential impact of these pesticides on organisms in vivo.

Acetylcholinesterase↗
PubMed2004

Lung function and respiratory symptoms of pesticide sprayers in state farms of Ethiopia.

Chemical pesticides are health hazards affecting the livelihood of those who are occupationally engaged in spraying farm fields. The objective of the study was to determine the extent of the hazard of chemical pesticide application by farm workers in selected farms. The major parameters used were measurements of lung function and respiratory symptoms. The design of the study was cross-sectional and was conducted in four state farms. Lung function and respiratory symptoms of 102 pesticide sprayers of state farms of Ethiopia and of 69 non-sprayers were assessed All data were analysed by decade age groups adjusting for smoking habits. The results of lung function and respiratory symptoms of 102 pesticide sprayers and of 69 non-sprayers are presented. The 15-24 years age group of pesticide sprayers had significantly reduced forced expiratory vital capacity (FVC) and forced expiratory volume in one second (FEV1), as compared to that of similar age group non-sprayers. Analysis of variance on FVC and FEV for the five predictors (age, height, weight, chest circumference and FFM) of the non-sprayers was highly significant (F = 4.647, 5.563 & P = 0.001, 0.000 for FVC and FEV1 respectively). 5.9% and 16.7% of the pesticide sprayers had symptoms of cough and breathlessness respectively. Pesticide applications resulted in reduced lung function and evoking respiratory symptoms. Pesticide sprayers need to be sensitised to the hazardous consequences of pesticide applications for human health and the environment and should be encouraged to wear personal protective devices during work on farms.

Adolescent↗
PubMed2005

Development of biofilters to treat the pesticides wastes from spraying applications.

Several studies carried out in Europe showed the importance of direct losses to the contamination of surface water by pesticides. These pesticides losses can occur at the farm site when the sprayer equipment is filled with the pesticide formulation (spills, overflowing, leaking) and during the clean-up (rinsing) of the sprayer after the treatment. In Belgium studies are carried out on biofilters to treat in an efficient way effluents containing pesticides. The biofilter substrate is elaborated from a homogenised mixture of local soil, chopped straw and peat or composted material, able to absorb or degrade the active substances. Biofilters consist in systems of 2 or 3 units depending on the spray equipment of the farmer and on the configuration of the farmyard. Each unit is made from a 1 m3 plastic container and the different units are stacked in a vertical pile and connected between them using plastic valves and pipes. Eight pilot systems were installed in March 2002 in seven farms and in one agricultural school, all selected in the loamy region of Belgium specialised in arable crops such as cereals, sugar beets and vegetables. The efficacy (yield) of the systems was determined by measuring the balance of the inputs and outputs of the pesticides. Results were expressed in percent of pesticide retained on the biofilters. The results obtained after two years with 5 tracer pesticides (atrazine, carbofuran, diuron, lenacil and simazine) brought on the biofilter installations are very satisfactory since the percentage of retention is generally higher than 95% of the amount applied. In the beginning of 2004, ten new pilot biofilters were installed in several farms or agricultural technical centres (producing cereals, sugar beets, potatoes, vegetables, fruits or ornamental plants), and in a municipal maintenance service. Some biofilters were installed in duplicate in order to compare the efficacy of different substrates. The efficacy of the biofilters was studied for the 5 classical tracer pesticides but also for other chemical classes of herbicides (sulfonylurea, aryloxyalcanoic acids, chloroacetanilides), insecticides (pyrethroids, carbamates) and fungicides (dicarboximides, phenylamides, triazoles and strobilurines). To monitor these pesticides in elutes and substrates, two analytical methods were developed, optimised and validated : the first one by Gas Chromatography with Mass Spectrometry Detection (GC-MS), and the second one by High Performance Liquid Chromatography with UV Diode Array Detection (HPLC-DAD). The micro-organisms activity in the substrate was also measured in some situations.

Biodegradation, Environmental↗
PubMed1994

Pesticides: a review article.

The use of a wide range of chemicals to destroy pests and weeds is an important aspect of agricultural practice in both developed and developing countries. Undoubtedly, this has increased crop yield and reduced postharvest losses. However, the expanded use of such pesticides expectedly results in residues in foods, which has led to widespread concern over the potential adverse effects of these chemicals on human health. It is clear that the possibility for exposure to pesticides is greatest among farm workers. Also, it is exceedingly plausible that less controlled and regulated uses of pesticides may offer the greatest opportunity for exposure to toxicologically significant quantities. Very limited epidemiological data are available for evaluation of the health effects of pesticides on humans. Only a small proportion of a population is likely to receive a pesticide dose high enough to cause acute severe effects; however, many more may be at risk of developing chronic effects (such as cancer, adverse reproductive outcome, and immunological effects) depending on the type of pesticide they are exposed to. The pesticides currently in use include a wide variety of chemicals with great differences in their mode of action, uptake by the body, metabolism, elimination from the body, and toxicity to humans. With pesticides that have a highly acute toxicity but are readily metabolized and eliminated, the main hazard lies in acute, short-term exposures. With others that have a lower acute toxicity but show a strong tendency to accumulate in the body, the main hazard is connected with long-term exposure, even to comparatively small doses. Other pesticides that are rapidly eliminated but induce persistent biological effects also present a hazard connected with long-term, low-dose exposures. Adverse effects may be caused not only by the active ingredients and the associated impurities, but also by solvents, carriers, emulsifiers, and other constituents of the formulated product. This review attempts to describe several aspects of the problem.

Environmental Exposure↗
PubMedDate not supplied

Matrix solid-phase dispersion extraction and gas chromatographic screening of 14 chlorinated pesticides in oysters (Crassostrea virginica).

A multiresidue isolation technique known as matrix solid-phase dispersion (MSPD) is presented for the extraction and subsequent gas chromatographic/electron capture detection (GC/ECD) determination of 14 chlorinated pesticides (alpha-BHC, beta-BHC, lindane, heptachlor, aldrin, heptachlor epoxide, p,p'-DDE, dieldrin, endrin, 4,4'-DDD, endrin aldehyde, p,p'-DDT, endosulfan sulfate, and methoxychlor) from oysters (Crassostrea virginica). Pureed whole oysters (0.5 g aliquots) are fortified with the 14 pesticides and delta-BHC, as an internal standard, and blended with 2 g C18 (octadecylsilyl)-derivatized silica. Pesticides are eluted from an extraction column composed of C18/oyster matrix blend and 2 g activated Florisil by addition of 8 mL acetonitrile-methanol (90 + 10). Then, 2 microL of the eluate is analyzed by GC/ECD. Unfortified blank controls are treated similarly. The eluate contained all the pesticide analytes and was free of interfering coextractants. Correlation coefficients for the standard curves of the 14 extracted pesticides (linear regression analysis) ranged from 0.9849 to 0.9980. Average relative percent recoveries over the range of concentrations examined (66 +/- 12.7% to 84 +/- 25.3%, n = 25 for each pesticide), interassay variability (13.6 +/- 8.8% to 30.2 +/- 9.1%, n = 25 for each pesticide), and intra-assay variability (5.8-11.8%, n = 5 for each pesticide) indicated that the MSPD methodology successfully extracted and determined the 14 chlorinated pesticides in oyster at levels of 31.3-500 ng/g.

Animals↗
PubMed1992

Family pesticide use in the home, garden, orchard, and yard.

This study examined family use of pesticides in the home, garden, orchard, and yard. Data were collected from 238 families in Missouri during telephone interviews from June 1989 to March 1990. Nearly all families (97.8%) used pesticides at least one time per year and two thirds used pesticides more than five times per year. More than 80% used pesticides during pregnancy and 70% used pesticides during the first 6 months of a child's life. The most common setting for family pesticide use was in the home, where 80% of families used pesticides at least once per year. This was followed by herbicide use to control yard weeds (57% of families) and insecticide use to control fleas and ticks on pets (50% of families). A substantial number of families also used pesticides in the garden or orchard (33%). Flea collars were the most popular pest control product (50% of families). Carbaryl or Sevin was also popular, with 28.2% of families reporting use. No-pest-strips (dichlorvos) and Kwell shampoo (lindane) were used by almost 10% of participating families. Examination of study data revealed that families limited exposure to pesticides for the mother during pregnancy and for children during the first 6 months of life. Families failed to recognize and reduce pervasive exposures associated with no-pest-strips and flea collars.

Animals↗
PubMed2000

A theoretical approach to the mechanism of biological oxidation of organophosphorus pesticides.

Organophosphorus pesticides are the most common classes involved in poisonings related to pesticides. We used enzymatic activity of chloroperoxidase on the metabolism of some phosphorothioate pesticides published previously and molecular mechanics methods to perform a theoretical approach of the mechanism of biological oxidation of this class of pesticides. The molecular structure of eight pesticides were optimized by molecular mechanics methods using the CAChe program package for biomolecules, ver. 3.11 (Oxford Molecular Ltd., Campbell, CA). Total energy resulted from the structure optimization process and the partial charges of both phosphorus and sulfur were computed for every pesticide. Phosphorus partial charge and enzymatic activity were significantly related by linear regression analysis (r=0.82, P<0.05). Analyzing our results and using previously reported enzymatic activity of chloroperoxidase on these pesticides, we deduced chemical events involved in activation of the active site of chloroperoxidase and proposed a novel mechanism of oxidation for this class of pesticides. This mechanism will also help to understand the oxidation process of pesticides by cytochrome P450, and production of toxic metabolites.

Chemical Phenomena↗
PubMed2005

Construction and evaluation of a humic acid column: implication for pesticide risk assessment.

In this paper, humic acid (HA), known to play a large role in the binding and transport of pesticides in soil, was immobilized on a chromatographic support. Then, the association of some herbicides and rodenticides with the main soil component HA was examined using this novel chromatographic column. It appeared that HA has a lower affinity for neutral than for charged pesticides. Moreover, the influence of various parameters was investigated on the pesticide retention in order to providevaluable information about both the binding mechanism and the utilization conditions of the HA column. For all the pesticides studied, a change was clearly vizualized in the HA-pesticide association mechanism at a critical value of the Na+ concentration in the bulk solvent, x(c), equal to 0.6 M. Around this value, the HA structure balanced between a flexible linear conformation for x < x(c) and a random coil form for x > x(c). This work confirmed the conformation change on HA immobilized on silica. As well, only for the charged pesticides, it was clearly pointed out that below a Na+ concentration equal to 0.3 M, the pesticide binding to HA decreased when the salt concentration was enhanced due to an ion pair formation and a competition effect between the sodium cation and pesticide to bind to the HA molecule. Furthermore, it was established that the HA column was stable during an extended period of time, indicating that the HA column could soon become very attractive to determine the risk assessment of pesticides.

Herbicides↗
PubMed2004

Geochemical modulation of pesticide sorption on smectite clay.

Pesticide adsorption by soil clays can be dramatically influenced by the exchangeable cations present. Among the common exchangeable base cations in soils (Ca2+, Mg2+, K+, and Na+), K+-saturated clays frequently demonstrate the strongest affinity for pesticides. In the presence of multiple exchangeable cations in the system, we hypothesize that the magnitude of pesticide sorption to soil minerals is proportional to the fraction of clay interlayers saturated with K+ ions. To test this hypothesis, we measured sorption of three pesticides with different polarities (dichlobenil, monuron, and biphenyl) by homoionic K- and Ca-smectite (SWy-2) in KCl/CaCl2 aqueous solutions. The presence of different amounts of KCl and CaCl2 resulted in varying populations of K+ and Ca2+ on the clay exchange sites. The sorption of dichlobenil and, to a lesser extent monuron, increased with the fraction of K+ on clay mineral exchange sites. Ca- and K-SWy-2 displayed the same sorption capacities for nonpolar biphenyl. X-ray diffraction patterns indicated that at lower fractions of K+-saturation, exchangeable K+ ions were randomly distributed in clay interlayers and did not enhance pesticide sorption. At higher populations of K+ (vs Ca2+), demixing occurred causing some clay interlayers, regions, or tactoids to become fully saturated by K+, manifesting greatly enhanced pesticide sorption. The forward and reverse cation exchange reactions influenced not only K+ and Ca2+ populations on clays but also the nanostructures of clay quasicrystals in aqueous solution which plays an important, if not dominant, role in controlling the extent of pesticide sorption. Modulating the cation type and composition on clay mineral surfaces through cation exchange processes provides an environmental-safe protocol to manipulate the mobility and availability of polar pesticides, which could have applications for pesticide formulation and in environmental remediation.

Adsorption↗
PubMed2003

Nondietary ingestion of pesticides by children in an agricultural community on the US/Mexico border: preliminary results.

An environmental measurement and correlation study of nondietary ingestion of pesticides was carried out in a colonia in south Texas. The purpose of the study was to evaluate young children's exposure to environmental levels of organophosphate (OP) pesticides in the household. Samples were collected to measure levels of OP pesticides in housedust and on children's hands. These, in turn, were compared to levels of OP pesticide metabolites in urine. A total of 52 children, 25 boys and 27 girls, participated in the spring and summer of 2000. The children were 7-53 months of age at the time of recruitment. Univariate and multivariate regression analyses were carried out using SAS statistical software. Seventy-six percent of housedust samples and 50% of hand rinse samples contained OP pesticides. All urine samples had at least one metabolite and over 95% had at least two metabolites above the limit of detection (LOD). Total OP loadings in the housedust ranged from nondetectable (nd) to 78.03 nmol/100 cm(2) (mean=0.15 nmol/100 cm(2); median=0.07 nmol/100 cm(2)); total OP loadings on the children's hands ranged from nd to 13.40 nmol/100 cm(2) (mean=1.21 nmol/100 cm(2); median=1.41 nmol/100 cm(2)), and creatinine corrected urinary levels (nmol/mol creatinine) of total OP metabolites ranged from 3.2 to 257 nmol/mol creatinine (mean=42.6; median 27.4 nmol/mol creatinine). Urinary metabolites were inversely associated with the age of the child (in months) with the parameter estimate (pe)=-2.11, P=0.0070, and 95% confidence interval -3.60 to -0.61. The multivariate analysis observed a weak association between concentrations of OP pesticides in housedust, loadings in housedust, and concentration on hands, hand surface area, and urinary levels of OP metabolites. However, hand loadings of OP pesticides were more strongly associated (r(2)=0.28; P=0.0156) with urinary levels of OP metabolites (pe=6.39; 95% CI 0.98-11.80). This study's preliminary findings suggest that surface loadings of pesticides, on hands, are more highly correlated with urinary bioassays and, therefore, may be more useful for estimation of exposure in epidemiologic studies than levels of pesticides in housedust.

Administration, Cutaneous↗
PubMed2005

Uptake and modeling of pesticides by roots and shoots of parrotfeather (Myriophyllum aquaticum).

INTENTION, GOAL, SCOPE, BACKGROUND: Aquatic plants have a great potential to function as in situ, on-site biosinks and biofilters of pollutants. They are used for phytoremediation and phytotoxicity studies. Pesticide uptake studies are very important to predict contaminant accumulation, translocation, and transformation. There are a lot of models which have been developed for emergent plants, but there are not any existing models for submerged aquatic plants for assessing pesticide uptake. OBJECTIVE: In this study, uptake of selected pesticides in parrotfeather (Myriophyllum aquaticum) were studied and the results were modeled with the aid of Log Kow and the concentration of pesticides. At the end, the developed model was compared to other existing models. METHODS: The test was conducted with parrotfeather as a model plant. The bioassay and cultivation of this plant were examined. Pesticide uptake by roots and shoots was determined using 14C-radiolabeled materials. RESULTS AND DISCUSSION: The results were fitted with an equation that showed a relationship between uptake and lipophilicity of pesticides. The model was compared with other pesticide uptake models developed for other plants. Atrazine and cycloxidim were taken up more by roots than by shoots in comparison to other pesticides used. The total uptake, both in shoots and roots, was lower than for terbutryn and trifluralin. The best appropriate model was developed from the results against the other models seen in the literature. The concentration factors (Root Concentration Factor (RCF) and Submerged Shoot Concentration Factor (SSCF)) increased with a higher Kow of the substances. The Submerged Shoot Concentration Factor (SSCF) revealed a better relationship of the chemicals than did the Root Concentration Factor (RCF). CONCLUSIONS: In this study, an uptake model was developed for rooted, submerged aquatic plants. Further studies are necessary to develop and compare models with different plants and pesticides. RECOMMENDATION AND OUTLOOK: Such studies as this one may be extended to other environmental pollutants in the aquatic ecosystem and may be employed to evaluate the possibility of using different plants in phytoremediation studies.

Atrazine↗
PubMed1997

The problems associated with pesticide use by irrigation workers in Ghana.

The use of pesticides in Ghanaian agriculture, though beneficial in reducing crop loss both before and after harvest, has been associated with threats to human health often due to the misapplication of the chemicals. This study was an initial attempt to explore the knowledge, attitudes and practices of 123 farm workers on three irrigation project areas in the Accra Plains, Ghana, regarding the safe handling and use of pesticides, to assess the prevalence of symptoms associated with organophosphorus pesticides (OPs) and carbamates and to determine the prevalence of pesticide-related symptoms, and blood cholinesterase. The study design was cross-sectional in type. Methods used were interviews and observation, and biological monitoring. The results revealed moderate levels of knowledge of the routes of absorption of pesticides and of potential symptoms following exposure. Knowledge of personal protective measures was poor to moderate. High risk practices included frequent handling of the chemicals, home storage of pesticides and short re-entry intervals. Despite knowledge of some health risks associated with pesticides, the use of personal protective equipment (PPE) was minimal due primarily to financial constraints. The prevalence of symptoms was higher and cholinesterase levels lower than in a control group of teachers. It is suggested that there is a need for more epidemiologic studies to investigate the problems associated with pesticide induced ill health as well as research into appropriate and affordable PPE. PPE needs to be subsidized. Training of agriculture and health workers in safety precautions, recognition, and management of pesticide-related ill health is a matter of urgency.

Adult↗