Pesticide

Fruit growers from three districts of the Punjab took part in this study whereas their knowledge, attitude, skill and practices were evaluated regarding the use of pesticides. The hygiene and sanitation practices of the respondent were also related with proper use of PPA ...

Background: All over the world, the use of pesticides is considered the most attractive method of controlling pests which involves less labor and characterizes higher output per hectare of land. I aim to study to assess Farmers Knowledge and Practices of Pesticides used and self-reported health systems associated with pesticides used in Thimi, Bhaktapur.   Methodology: A cross-sectional study was conducted among farmers of Thimi, Bhaktapur. 210 farmers were enrolled in the study. Data collection involved a self-prepared questionnaire to farmers and information was collected by face to face interviews. Socio demographics status, unsafe pesticide handling practices of pesticide storage, conditions of personal protective equipment (PPE) was assessed as per the questionnaires. Results: Out of 210 farmers, who participated in the study, 70% were male and 30% were female. Majority 87% of farmers couldn’t read and write. Knowledge regarding the personal protective equipment was known to 85...

Organophosphorus pesticides and pyrethroids are widely used in German agriculture and residential settings. Their occurrence in human biological samples can be used as an indicator for the exposure of children to these compounds. Using multivariate evaluation the routes of exposure can be identified. In the pilot study of GerES IV, metabolites of pyrethroids and organophosporus pesticides were analysed in urine of children aged 2-17 years (n ¼ 396 and 363). The 95th percentiles for the metabolites of the pyrethroids in urine were: cis-DCCA 0.74 mg/l, trans-DCCA 1.7 mg/l, DBCA 0.52 mg/l, F-PBAo0.1 mg/l, and 3-PBA 2.4 mg/l. 3-PBA was detected in 90% of the samples. The 95th percentiles for the organophosphorus metabolites in urine were: DMP 118 mg/l, DEP 20 mg/l, DMTP 124 mg/l, DETP 11 mg/l, DMDTP 11 mg/l, DEDTPo1.0 mg/l. DMTP was the metabolite most frequently detected in the samples (90%).

door survey was conducted in Costa Rica 3 identib consumer attitudes and concerns about the safety of fruits and vegetables available in the marketplace. m e sample (n = 98) was randomly selected from a panel of 255 households in urban and rural areas. More than half the respondents (54%) expressed confidence in the safety of the produce available in the marketplace, while a minority (11 %) reported avoiding the consumption of some produce due to food safety concerns. A majority of respondents (64% agreed that the only way farmers control pests today is by using pesticides and that these are used indiscriminately (57%). Yet, 53% of the sample agreed that growers today use many practices to protect the environment and provide safe food. Consumers (48%) perceived farmers to be concerned about the environment and safe food, and agree (43 %) that farmers carefully manage the use of chemicals and other techniques to produce clean, safe, fresh food. m e majority (65%) of respondents were aware of the training programs and technical assistance provided to farmers on the use of chemicals by the Ministry of Agriculture and Cattle (MAG). Information sources on which consumers rely are television (92 %), radio (73 %), and newspapers (63%). mese findings show that while many consumers are not completely confident in the chemical safety of produce, few have reduced produce consumption. Consumers are also concerned with the perceived indiscriminate use of pesticides by farmers. Since public confidence appears to be high for MAG, the government may want to use MAG and the mass media to provide consumer education programs on food safety that specifically address the use of pesticides by farmers.

The photochemical behavior of oxyfluorfen [2-chloro-1-(3-etoxy-4-nitrophenoxy)-4-(trifluoromethyl) benzene] on two Greek soils was investigated. Soils were sampled from Nea Malgara and Preveza regions, characterized by a different organic matter content. Soils were spiked with the diphenyl-ether herbicide and irradiation experiments were performed either in the laboratory with a solar simulator (xenon lamp) or outside, under natural sunlight irradiation; other soil samples were kept in the dark to control the retention reaction. Kinetic parameters of both retention and photochemical reactions were calculated using zero-, first- and second- (Langmuir-Hinshelwood) order equations, and best fit was checked through statistical analysis. The soil behaviors were qualitatively similar but quantitatively different, with the soil sampled from the Nea Malgara region much more sorbent as compared with Preveza soil. All studied reactions followed second-order kinetics and photochemical reaction...

Soil fumigation has recently been shown to affect the greenhouse gas balance by increasing emissions of nitrous oxide (N 2 O) following chloropicrin (CP) application. However, the exact mechanisms of this increase were not investigated. The purpose of this study was to elucidate potential mechanisms of CP-induced N 2 O production through laboratory incubations using chemical inhibitors (acetylene, antibacterial, antifungal, and oxygen), isotopically labeled 15 N-CP, and pH modifications of a forest nursery soil. Results showed that N 2 O production increased by 12.6 times following CP fumigation. Microbial activity contributed 82% to the CP-induced N 2 O production, with the remaining 18% from abiotic processes as determined by incubation with sterilized soil. Inhibitor studies suggested that 20% of the N 2 O production was from bacteria and 70% from fungi. There were no significant differences in N 2 O production following CP fumigation under various levels of acetylene (0, 10, and 10 kPa), suggesting that traditional nitrification and denitification reactions did not significantly contribute to N 2 O production following CP fumigation. 15 N labeled studies indicated that 12% of fumigant source N was incorporated into the produced N 2 O. No enrichment in N 2 was observed, indicating that N 2 O was one of the terminal biotic mineralization products of CP. Production of N 2 O is aerobic and production rates increased with increasing oxygen concentrations. Our data strongly suggested that fungal mediated denitrification reactions under aerobic conditions were the primary mechanism for CP-induced N 2 O production.

The effects of paraquat on rat brain were studied. Activities of complex I (NADH: ubiquinone oxidoreductase) in mitochondrial electron transport system, lipid peroxidation and the amount of catecholamines in rat brain were measured after acute paraquat exposure. Complex I activities were significantly lower and lipid peroxides were higher in the brains of a paraquat-treated group than in those of a control group. Lipid peroxide in rat serum, however, did not increase after paraquat exposure. A study of the time dependency of paraquat effects disclosed that mitochondrial complex I activities in rat brain as well as those in rat lung and liver gradually decreased prior to the appearance of respiratory dysfunction. As compared to controls, the dopamine in rat striatum was significantly lower in the paraquat-treated group. These results suggest that paraquat after crossing the blood-brain barrier might be reduced to the radical in rat brain, which may damage the brain tissue, especially dopaminergic neurons in striatum. We therefore propose that cerebral damage should be taken into consideration on paraquat exposure. Patients may therefore need to be followed up after exposure to high doses of paraquat.

It has been developed a general strategy for the determination of pesticides in agrochemicals by Fourier transform near infrared (FT-NIR) spectroscopy. The methodology is based on previous extraction of the active principles through sonication with acetonitrile and direct determination by transmission measurements, using glass vials as measurement cells and univariate calibration at selected wavenumbers as a function of the pesticide to be analyzed. Chlorsulfuron, metamitron, iprodione, pirimicarb, procymidone and tricyclazole were used as test molecules and data obtained by FT-NIR for 20 samples containing one of these active principles compare well with those found by reference liquid chromatography (HPLC) procedures. In short, FT-NIR provides relative standard deviations between 0.04 and 0.7% and limit of detection values ranging from 0.004 to 0.17 mg g −1 with recovery values between 96.4 and 100.5%. On the other hand, FT-NIR offers a 10 times faster methodology than chromatography ones and an environmentally friendly alternative which reduces the reagent consumption to 1 mL acetonitrile per sample.

In ecotoxicological studies involving community-level investigations, rapid and multiparametric fluorescence-based methods may provide substantial advantages over traditional methods used for structural and functional community analysis. Therefore, multiwavelength-excitation pulse-amplitude modulated (PAM) fluorometry was applied in this study to assess long-term changes in periphyton community structure, shortterm effects on periphyton functioning (photosynthesis) and pollution induced community tolerance (PICT). For inter-calibration, periphyton structure was evaluated by chemotaxonomic analysis of accessory pigments and a four-wavelength-excitation PAM fluorometer. Short-term effects of herbicides were evaluated by fluorescence quenching analysis and 14 C-incorporation as a proxy of primary production. Subsequently, the method was applied to assess structural and functional changes in periphyton communities after isoproturon exposure for 14 and 26 days, respectively. Results showed good correlation of the PAM fluorescence-based measurements with traditional methods for biofilms in the initial colonisation phase for structural and functional parameters. However, for biofilms older than 9 weeks PAM fluorescence may underestimate biomass. Multiwavelength-excitation PAM fluorometry showed good correlation with marker pigment concentrations indicating that this method provides a reliable estimate of the community structure. PAM fluorometry was able to quantify changes of biomass and follow relative shifts in class composition of biofilms under exposure of isoproturon. Short-term tests based on the quantification of the inhibition of the effective quantum yield revealed a concentration-dependent increase of PICT. The observation of two succession phases of the biofilms after 14 and 26 days of growth, respectively, revealed that sensitivity of biofilms decreased with increasing age and biomass, respectively, but PICT remained a characteristic parameter of exposed communities in a concentration-dependent relationship. In conclusion, multiwavelength-excitation PAM fluorometry has considerable potentials in multispecies and multiparameter assessment of toxic effects on community level in terms of (1) a combined and rapid evaluation of structural and functional parameters in parallel, (2) screening of trends over time, (3) observing effects in replication and (4) being non-destructive. The approach therefore provides a perspective for a better understanding of community-level effects as species interactions in terms of PICT and therefore a higher ecological realism in risk assessment of toxicants.

H ard red wheat (Triticum aestivum L.) is grown on more than 12 million hectares in the Great Plains region of the United States and weed control is an important management consideration for wheat producers each year (USDA-National Agriculture Statistic Service, 2006). Weeds, particularly annual grasses, can be diffi cult to selectively control in wheat. Development of herbicide-resistant crops has resulted in new opportunities for selective weed control in many crops including wheat, and, in some cases, has simplifi ed weed management. Herbicide-resistant crops allow for expanded use of certain broad spectrum herbicides with favorable environmental profi les (

Both visible near-infrared (VNIR) and mid-infrared (MIR) spectroscopy have been claimed to better predict pesticide sorption in soils than other methods. We compared the performances of VNIR and MIR spectroscopy for predicting both organic carbon content (f OC ) and the sorption affinity (K d ) of diuron in 112 surface soils from South Australia. Separate calibration models were developed between VNIR and MIR spectra, and f OC and K d using partial least-squares (PLS) regression. MIR clearly outperformed VNIR for predictions of both f OC and K d in soils. Correlation (R 2 ) and accuracy (RPD) indices were 0.4 and 1.3 for the VNIR-PLS model versus 0.8 and 2.3 for the MIR-PLS model, respectively, for K d prediction. PLS loadings for sorption prediction were compared in terms of the soil information they contained. While VNIR loading did not include any direct spectral information regarding soil minerals, MIR loading included peaks associated with sand, clays, and carbonates. Perhaps by better predicting f OC and integrating the effects of OC as well as minerals, the MIR-PLS model provided a better prediction for diuron K d values in our calibration set.

Triadimefon is a triazole fungicide that produces hyperactivity in both mice and rats similar to that seen following administration of compounds with catecholaminergic activity (e.g., d-amphetamine). To determine whether the triadimefon-induced hyperactivity is due to an action on CNS catecholaminergic systems, we evaluated the effects of combined treatment of triadimefon with either the tyrosine hydroxlase inhibitor d,l-a-methyl-p-tyrosine methyl ester HCl

The production of coca and poppy as well as the processing and production of cocaine and heroin involve significant environmental impacts. Both coca and poppy are grown intensively in a process that involves the clearing of land in remote areas, the planting of the crop, and protection against pests such as weeds, insects, and pathogens. The aerial spray program to control coca and poppy production in Colombia with the herbicide glyphosate is conducted with modern state-of-the-art aircraft and spray equipment. As a result of the use of best available spray and navigation technology, the likelihood of accidental off-target spraying is small and is estimated to be less than 1% of the total area sprayed. Estimated exposures in humans resulting from direct overspray, contact with treated foliage after reentry to fields, inhalation, diet, and drinking water were small and infrequent. Analyses of surface waters in five watersheds showed that, on most occasions, glyphosate was not present ...

The effects of prescribed burning, herbicide application, and thinning treatments were examined in upland Quercus stands with a replicate block field study. Two site types were analyzed: (1) nonsuccessional with a Quercus overstory and Quercus understory, and (2) successional with a Quercus overstory and an Acer saccharum understory. Treatments were examined for their effects on vegetation structure and composition, especially with respect to altering the natural succession from Quercus communities to mesophytic species. In addition, impacts of burning on soil nutrients were examined prior to and immediately following burn treatments. Results from the study indicate that fire had little effect on A horizon soil nutrients following burns. The data suggest fire plays a more important role as a decomposer for nutrient release in February burns than in November burns. Natural precipitation and leaching from the litter layer in the fall rendered similar nutrient dynamics as burning in November. The structural changes to vegetation following fire were more noticeable than compositional changes. Thinning of the canopy was generally necessary for the understory to respond to burning treatments. Burning did not affect stems >3.8 cm dbh (diameter at breast height). Density of most woody species <3.8 cm dbh decreased with burning, but increased with burning and thinning, indicating the stress of shaded conditions. Thus, burning prior to thinning may be an effective method for controlling an A. saccharum invasion into Quercus stands. Herbaceous, seedling, sapling, and overstory strata diversity were unaffected by the treatments. Data indicated that the community responds with species extant at the time of treatment. Thus, the initial conditions prior to disturbance were important factors in the response of the stand to disturbance. Although fire has played a major role in upland forest dynamics prior to settlement, forest structure and composition can no longer be maintained by fire. Succession without fire has resulted in a different structure and composition to oak forests, altering both fuels and fuel moisture levels. Species normally considered intolerant of fire have reached size classes large enough that they tolerate cool to moderate burns. More severe disturbance techniques, or combinations of techniques, are necessary for sustainable oak forest management in the central hardwood region.

This Opinion paper briefly summarizes the views of the authors on the directions of research in the area of plant protection chemistry. We believe these directions need to focus on (1) the discovery of new pesticide active ingredients, and (2) the protection of human health and the environment. Research revenues are discussed thematically in topics of target site identification, pesticide discovery, environmental aspects, as well as keeping track with the international trends. The most fundamental approach, target site identification, covers both computer-aided molecular design and research on biochemical mechanisms. The discovery of various classes of pesticides is reviewed including classes that hold promise to date, as well as up-to-date methods of innovation, e.g. utilization of plant metabolomics in identification of novel target sites of biological activity. Environmental and ecological aspects represent a component of increasing importance in pesticide development by emphasizing the need to improve methods of environmental analysis and assess ecotoxicological side-effects, but also set new directions for future research. Last, but not least, pesticide chemistry and biochemistry constitute an integral part in the assessment of related fields of plant protection, e.g. agricultural biotechnology, therefore, issues of pesticide chemistry related to the development and cultivation of genetically modified crops are also discussed.

Adherence with permethrin-treated bed net (ITN) use and their proper deployment was directly observed in 2,178 individuals (784 households) participating in a large-scale trial of ITNs on child mortality in western Kenya. The ITNs were distributed free of charge to ensure high coverage, resulting in a ratio of 1.46 persons per ITN. Approximately 30% of ITNs present were unused. The overall percentage adherence was 72.3%. The probability of adherence by individuals depended strongly on age (relative risk [RR] ‫ס‬ 0.86, 95% confidence limit [CL] − 0.78-0.94), in which children less than five years of age were less likely to use ITNs than older individuals, and temperature, in which ITNs were more likely to be used in periods of cooler weather. A marginally significant diminution in adherence during the second year of the project was also observed (RR ‫ס‬ 0.83, 95% CL ‫ס‬ 0.68-1.01). Mosquito numbers, relative wealth, number of house occupants, and the educational level of the head of the household had no effect on adherence. In unstructured questioning of house residents, excessive heat was often cited as a reason for not deploying the child's ITN. The most important reason for non-adherence was disruption of sleeping arrangements, indicating that ITNs were not readily redeployed in the face of shifting sleeping patterns due to visitors, funerals, house construction, and other events. Challenges faced by health education programs to maximize adherence with ITN use are discussed.

Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and its metabolites, chlordanerelated compounds (CHLs), mirex, hexachlorocyclohexane isomers (HCHs), dieldrin, and hexachlorobenzene (HCB) were determined in blubber of harbor seals (Phoca vitulina concolor) from the northwestern Atlantic coast. PCBs, DDTs, and CHLs were the major persistent organochlorines in harbor seal blubber, while mirex, HCHs, dieldrin, and HCB were minor contaminants. Highest concentrations were found in the adult males, followed by the pups, yearlings, adult females, and fetuses. DDT and PCB concentrations have declined from the high levels reported in the early 1970s, but no declines were observed in our samples over the ten-year period 1991-2001. DDT/PCB ratios were indicative of a more rapid decline of DDTs than PCBs, while ratios of p,p 0 -DDE/DDT were indicative of a metabolic ''weathering'' of DDT. The population appears to be susceptible to disease outbreaks, as evidenced by a recurrence of viral epizootics since the late 1970s. The PCB burdens in these seals are similar to levels reported in seals from polluted regions of Europe and Asia, and exceed the estimated threshold levels for adverse reproductive and immune system effects in the species.

‘Sylgard® 309’ organosilicone surfactant is a very effective adjuvant for broadleaf weed control with a number of herbicides. It is also effective in providing rainfastness lo these post-emergence herbicide applications. To elucidate the basis for herbicide activity enhancement and rainfastness, the absorption of [14C]acifluorfen, [14C]bentazone and [14C]‘Sylgard 309’ were studied. Non-ionic surfactants and crop oil concentrates were used as adjuvants with [14C]acifluorfen and [14C]bentazone, respectively, for purposes of comparison. Maximum absorption of [14C]acifluorfen and [14C]bentazone was obtained within 15 min after herbicide application with the organosilicone, versus ≥ 24 h with the convenlional adjuvants. [14C]-Organosilicone absorption closely paralleled that of the [14C]-herbicides. The organosilicone appears to exert its action by increasing greatly herbicide absorption. The enhancement effect did not appear to be a function of reduced surface tension. Rainfastness appeared to be a result of greatly accelerated herbicide penetration through the leaf cuticle in the presence of the organosilicone.

A method was validated for the multi-residue analysis of 82 pesticides in grapes at ≤25 ng/g level. Berry samples (10 g) mixed with sodium sulphate (10 g) were extracted with ethyl acetate (10 mL); cleaned by dispersive solid phase extraction and the results were obtained by liquid chromatography–tandem mass spectrometry. Reduction in sample size and proportion of ethyl acetate for extraction did not affect accuracy or precision of analysis when compared to the reported methods and was also statistically similar to the QuEChERS technique. The method was rugged (HorRat < 0.5) with <20% measurement uncertainties. Limit of quantification was <10 ng/g with recoveries 70–120% for most pesticides. The method offers cheaper and safer alternative to typical multi-residue analysis methods for grape.

An optical biosensor based on vegetal cells entrapped in an inorganic translucent matrix and fluorescence detection has been developed. The biosensor uses Chlorella vulgaris immobilized in a translucent support produced from sol–gel technology. The translucence of the structure enables the algal active layer to be placed directly in contact with the optical fibers for fluorescence detection. This configuration has many advantages over the use of an opaque support because no space between the optical fibers and the active layer is required to collect fluorescence. This reagentless biosensor allows determination of diuron as an anti-PSII herbicide and its long term activity is assessed.

A series of phenolic resin-based microporous activated carbon fibers (ACF) with different micropore size distributions were used to assess the role of pore size distribution (PSD) in the mechanism of competitive adsorption between the organic micropollutant, atrazine, and a compound larger in size, Congo red dye (CR). Batch kinetic and equilibrium experiments with the CR / atrazine system consisted of single-solute, simultaneous adsorption, CR preloading followed by atrazine contact, and atrazine preloading followed by CR contact. Based on the previous pore characterization studies and the PSD, two types of pore structures were proposed: telescopic pores and branched pores. With the telescopic pore structure, evidence is presented to support a transition from surface pore blockage to pore constriction (without loss of atrazine capacity) to direct competition for adsorption sites, with increasing average micropore size. With the branched pore structure (micropores branching off from mesopores), direct competition for adsorption sites in a fraction of the large micropores and pore constriction and pore blockage of smaller micropores were found to be important. The kinetics of adsorption was found to be important in determining the impact of simultaneous adsorption, while CR surface coverage and preloading time were the key factors controlling the impact of preloading on atrazine adsorption.

The impacts of the 30 active substances, most used in Costa Rica (reference year 1998), are evaluated using two models originally developed to support comparative assertions in the context of the life cycle assessment: the multimedia fate, exposure and effect model Impact Assessment of Chemical Toxics 2002 (IMPACT 2002), and the Dynamic Model for Pesticides Residues in Plants. Results show that only five active substances -namely diazinon, mancozeb, chlorothalonil, terbutylazine and ethoprophos -contribute to more than 75% of the aquatic ecotoxicity and yet represent less than 40% of the amount used. More than 90% of the human toxicity is generated by only two active substances -namely terbufos and chlorothalonil -whereas they represent less than 10% of the total amount used. Overall, it would be possible to achieve a 90% reduction of human toxicity and a 75% reduction of aquatic ecotoxicity due to pesticide used in Costa Rica, focusing on only a few active substances. For instance, propiconazole or tridemorph could potentially be replaced by chlorothalonil; ametryn, diuron or paraquat by glyphosate; terbufos by cypermethrin; methyl bromide by metam sodium. #

In the coastal area, 28% people of total population lives where 16% of total rice of Bangladesh is being produced. Although arable land is decreasing, modern technologies help to increase food production. However, impacts of inappropriate application of chemical fertilizer, pesticides and climate change constrain the agricultural progress. The objective of the current study is to find out suitable existing environmental friendly agricultural practice that can adapt with climate changing condition. Dacope and Dumuria upazilas of Khulna district were the study area which situate at the southwestern coastal region of Bangladesh. Three types of available agricultural practices had been identified which were rice cultivation, combined rice and fish culture, and vegetable cultivation. Ten Rice Farmers (RF), ten combined Rice and Fish Farmers (RFF), and five Vegetable Farmers (VF) had been interviewed. VF use comparatively low amount of chemical fertilizer than other farmers. Farmers do no...

A gas chromatographic method was developed for the simultaneous determination of 12 pyrethroids (tefluthrin, bifenthrin, fenpropathrin, cyhalothrin, permethrin, cyfluthrin, cypermethrin, a-cypermethrin, flucythrinate, fenvalerate, fluvalinate, and deltamethrin) in tomato puree, peach nectar, orange juice, and canned peas. A miniaturized extraction-partition procedure requiring small amounts of nonchlorinated solvents is used. Samples are extracted with acetone, partitioned with ethyl acetate-cyclohexane (50 + 50, v/v), and cleaned up on a Florisil cartridge. The final extract is analyzed by gas chromatography with both electron capture and mass spectrometric detection modes. Studies at fortification levels of 0.010-0.100 mg/kg gave mean recoveries ranging from 70.2 to 96.0% and coefficients of variation between 4.0 and 13.9% for all compounds. Quantitation limits were <0.010 mg/kg for electron capture detection.

The present study was conducted to assess the plant growth promoting activities of Mesorhizobium sp. in the presence of technical grade herbicides and its ameliorating effects on herbicide toxicity to chickpea grown in herbicide treated soils. The quizalafop-p-ethyl and clodinafop-tolerant Mesorhizobium isolate MRC4 recovered from the nodules of chickpea plants significantly produced IAA, siderophores, hydrogen cyanide and ammonia in medium amended with or without technical grade quizalafop-p-ethyl and clodinafop. Quizalafop-p-ethyl at 40, 80 and 120 lg kg À1 soil and clodinafop at 400, 800 and 1200 lg kg À1 soil in general, decreased the growth attributes of chickpea plants inoculated with Mesorhizobium MRC4 and un-inoculated chickpeas. The three concentrations of quizalafop-p-ethyl were comparatively more toxic and substantially decreased biomass, nodulation and leghaemoglobin content, nutrient uptake, seed yield and grain protein over the un-inoculated chickpea. Interestingly, Mesorhizobium isolate MRC4 with any concentration of the two herbicides significantly increased the measured parameters when compared to the plants grown in soils treated solely (without inoculant) with similar concentration of each herbicide. Conclusively, Mesorhizobium isolate MRC4 could be exploited as bio-inoculant for facilitating chickpea growth under herbicide stress.

Samples of polyethylene pellets were collected at 30 beaches from 17 countries and analyzed for organochlorine compounds. PCB concentrations in the pellets were highest on US coasts, followed by western Europe and Japan, and were lower in tropical Asia, southern Africa and Australia. This spatial pattern reflected regional differences in the usage of PCBs and was positively correlated with data from Mussel Watch, another monitoring approach. DDTs showed high concentrations on the US west coast and in Vietnam. In Vietnam, DDT was predominant over its metabolites (DDE and DDD), suggesting the principal source may be current usage of the pesticide for malaria control. High concentrations of pesticide HCHs were detected in the pellets from southern Africa, suggesting current usage of the pesticides in southern Africa. This study demonstrates the utility and feasibility of the International Pellet Watch approach to monitor POPs at a global scale.

An extraction method was developed to recover organochlorine pesticides (OCPs) associated with live and mercuric chloride-treated fungal mycelia. A Cladosporium sp. was inoculated into potato dextrose broth, DDT (90 mg / l) added and incubated for seven days. The combination of a microextraction procedure for aqueous-phase-associated DDT and a sonication extraction for mycelia-bound DDT, using dichloromethane as the extracting solvent, resulted in the recovery of 31-51% of added DDT. DDT recovery was increased to 62-65% by grinding the fungal mycelia before sonication. Alkali and nitric acid pretreatments were tested to increase the recovery of DDT associated with fungal mycelia, however, these treatments resulted in the production of unidentified DDT transformation products. Pretreating mycelia containing DDT in concentrated hydrochloric acid at 608C for 2, 4 and 6 h resulted in DDT recoveries of 90-91%, 99% and 101-102% respectively without the production of transformation products. When an OCP mixture (DDT, DDD and DDE) was added to fungal mycelia, between 89% and 96% of DDT, DDD and DDE were recovered from live cultures compared to 85-91% in mercuric chloride-treated cultures using the microextraction / hydrochloric acid pretreatment (608C / 6 h) sonication extraction method.

In an age when vector-borne diseases are emerging worldwide, personal protective measures are essential for shielding soldiers and other exposed persons from arthropod attack. The development of permethrin-impregnated clothing has been one recent advance in protecting persons at-risk. However, to date risk assessment has not been performed related to wearing permethrin-impregnated clothing over longer time periods. Therefore, this paper describes relevant toxicological aspects of permethrin and estimates the extent of dermal permethrin uptake by soldiers wearing impregnated uniforms by determining urine metabolites of permethrin.

This research studied the characteristics of poly(acrylamide) and methylcellulose (PAAm-MC) hydrogels as a novel adsorbent material for removal of pesticide paraquat, from aqueous solution, with potential applications in curbing environmental risk from such herbicides. PAAm-MC hydrogels with different acrylamide (AAm) and MC concentrations were prepared by a free-radical polymerization method. The capability of the hydrogels in removing paraquat dichloride from aqueous solution was determined using UV-Vis analysis. The scanning electron microscopy method was used to study the morphological properties of the hydrogels, and swelling degree (Q) of the hydrogels was also measured. The entrapped MC in PAAm chains provoked significant changes in morphological, hydrophilic, and adsorption properties of the PAAm-MC hydrogels. The adsorption capacity of hydrogels was strongly influenced by AAm, MC, and paraquat concentrations with the highest adsorption capacity (q eq ¼ 14.3 mg g À1) was observed for hydrogels synthesized with 6.0% AAm with 0.75% MC swollen in 45.7 mg L À1 of paraquat solution. Freundlich model performed better than Langmuir model in describing the adsorption isotherm of PAAm-MC/paraquat system, implying a heterogeneous surface. These results suggest that PAAm-MC hydrogels are potentially viable absorbents for removal of paraquat pesticide from aqueous solution and cleaning water contaminated with dyes, heavy metals, and others pesticides. V

Sustainable development remains a pressing priority for the Lake Naivasha Ramsar site, as a matter both of longterm protection of the lake ecosystem and of the economic and social progress that depends upon it. This must be addressed at catchment-scale to protect the 'ecosystem services' that constitute the region's primary resources. Sustainability principles highlight energy, fertilisers, pesticides and other aspects of chemical use, plastics, erosion and sedimentation, wildlife, water and socio-economic issues as central to sustainable development strategy, influenced by both intensive and subsistence farms across the catchment. Market forces and long-term self-interest provide compelling arguments for sustainable development, the delivery of which will depend upon education and the spreading of good practice, perhaps backed up by stewardship schemes. Alternatively, the adverse consequences of continued unsustainable practice are highly significant for the region.

A large number of hazardous compounds can be expected to be present in landfill leachates, many of which have not yet been identified. Thus this study screened samples from 12 Swedish municipal landfill sites for 400 parameters and compounds. More than 90 organic and metal organic compounds and 50 inorganic elements were detected, some of which seem to have not been detected before. Compounds detected include halogenated aliphatic compounds, benzene and alkylated benzenes, phenol and alkylated phenols, ethoxylates, polycyclic aromatic compounds, phthalic esters, chlorinated benzenes, chlorinated phenols, PCB, chlorinated dioxins and chlorinated furans, bromated flame-retardants, pesticides, organic tin, methyl mercury and heavy metals. The presence of this large number of hazardous compounds in landfill leachates should have a significant impact on future landfill risk assessments and the development of leachate treatment methods. We propose that future research should pay more atte...

Crop protection seldom takes into account soil heterogeneity at the field scale. Yet, variable site characteristics affect the incidence of pests as well as the efficacy and fate of pesticides in soil. This article reviews crucial starting points for incorporating soil information into precision crop protection (PCP). At present, the lack of adequate field maps is a major drawback. Conventional soil analyses are too expensive to capture soil heterogeneity at the field scale with the required spatial resolution. Therefore, we discuss alternative procedures exemplified by our own results concerning (i) minimally and noninvasive sensor techniques for the estimation of soil properties, (ii) the evidence of soil heterogeneity with respect to PCP, and (iii) current possibilities for incorporation of high resolution soil information into crop protection decisions. Soil organic carbon (SOC) and soil texture are extremely interesting for PCP. Their determination with minimally invasive techniques requires the sampling of soils, because the sensors must be used in the laboratory. However, this technique delivers precise information at low cost. We accurately determined SOC in the near-infrared. In the mid-infrared, texture and lime content were also exactly quantified. Non-invasive sensors require less effort. The airborne HyMap sensor was suitable for the detection of variability in SOC at high resolution, thus promising further progress regarding SOC data acquisition from bare soil. The apparent electrical conductivity as measured by an EM38 sensor was shown to be a suitable proxy for soil texture and layering. A survey of arable fields near Bonn (Germany) revealed widespread within-field heterogeneity of texture-related ECa, SOC and other characteristics. Maps of herbicide sorption and application rate were derived from sensor data,

A fast and environmentally friendly procedure has been developed for Fourier transform Raman (FT-Raman) determination of a quaternary ammonium compound, Mepiquat chloride, in pesticide emulsifiable concentrate formulations. The method is based on the measurement of peak area values between 711 and 701 cm À1 corrected using a baseline defined at 620 cm À1 and interpolated in an external calibration of Mepiquat chloride standards dissolved in water. FT-Raman spectra were collected over 1.5 min from samples confined in screw cap standard chromatographic glass vials, at a nominal resolution of 4 cm À1 accumulating 25 scans per spectra and using a laser power of 1000 mW. Five commercial samples containing around 4.5% (w/v) Mepiquat chloride (3.8% (w/v) Mepiquat) were analysed by the proposed FT-Raman procedure and results obtained were statistically comparable with those obtained by a chromatographic reference procedure. The developed FT-Raman procedure does not use toxic or harmful solvents and also minimises the contact of the operator with toxic products, being a fast alternative to the chromatographic procedure. #

The neem tree, Azadirachta indica, provides many useful compounds that are used as pesticides and could be applied to protect stored seeds against insects. However in addition to possible beneficial health effects, such as blood sugar lowering properties, anti-parasitic, anti-inflammatory, anti-ulcer and hepatoprotective effects, also toxic effects are described. In this study we present a review of the toxicological data from human and animal studies with oral administration of different neem-based preparations. The non-aqueous extracts appear to be the most toxic neem-based products, with an estimated safe dose (ESD) of 0.002 and 12.5 g/kg bw/day. Less toxic are the unprocessed materials seed oil and the aqueous extracts (ESD 0.26 and 0.3 mg/kg bw/day, 2 l/kg bw/day respectively). Most of the pure compounds show a relatively low toxicity (ESD azadirachtin 15 mg/kg bw/day). For all preparations, reversible effect on reproduction of both male and female mammals seem to be the most important toxic effects upon sub-acute or chronic exposure. From the available data, safety assessments for the various neem-derived preparations were made and the outcomes are compared to the ingestion of residues on food treated with neem preparations as insecticides. This leads to the conclusion that, if applied with care, use of neem derived pesticides as an insecticide should not be discouraged.

Gold nanoparticles (AuNPs) were electrodeposited onto a glassy carbon (GC) electrode to increase the sensitivity of the tyrosinase (TYR) electrode. By controlling the applied potential and time, the coverage of AuNPs at the TYR electrode was optimized with respect to the current response. The voltammetric measurements revealed a sensitive enzymatic oxidation and electrochemical reduction of substrate (phenol and catechol). The quantitative relationships between the inhibition percentage and the pesticide concentration in various water samples were measured at the TYR-AuNP-GC electrode, showing an enhanced performance attributed by the use of AuNPs.

The influence of water hardness and dissolved organic matter (DOM) on bioavailability of organic chemicals to Daphnia magna was studied by using benzo[a]pyrene (BaP), pyrene, atrazine, and 3,3Ј,4,4Ј-tetrachlorobiphenyl (TCB) as model compounds. Two types of DOM were used, namely Lake Kontiolampi, Joensuu, Finland water (KL) and Nordic reference fulvic acid (NoFA) dissolved in artificial freshwater. Binding of the four contaminants by KL DOM decreased with increasing water hardness. Furthermore, increasing hardness reduced the binding of BaP and pyrene to NoFA. The binding of atrazine and TCB by NoFA was low and was not significantly affected by water hardness. In the DOM-free samples, the bioconcentration of the four contaminants in D. magna usually was not affected by water hardness. In the presence of DOM, the bioconcentration factors (BCFs) were lower (except for atrazine) than in the DOM-free controls. In the presence of both types of DOM, increasing water hardness resulted in higher BCFs for BaP. The bioconcentration of pyrene and TCB increased with increasing water hardness in the presence of KL DOM. In conclusion, the effects of DOM and water hardness on bioavailability of hydrophobic chemicals depend on the type of chemical and on the properties of DOM.

The use of crop®elds by birds is largely unknown in southern Canada and consequently the risk incurred by pesticide use on bird populations cannot be adequately characterised. The activity patterns and relative interior to edge use of bird species were examined for four crops in southern Ontario to assess the susceptibility of different species to pesticide use. Altogether 138 species were identi®ed in the four crops over the 2 year period but only 25 species were recorded during 50% of visits in at least 1 month: 14 in corn (Zea mays L.), 16 in soybean (Glycine max L. Merr.), 14 in apple (Malus spp.) orchards and eight in vineyards (Vitis spp.). Territorial behaviour was an important activity for several species from May through July in the four crops. Nesting was con®rmed in May, June and July for most species, with the exception of American Gold®nch Carduelis tristis, Chipping Sparrow Spizella passerina and Cedar Waxwing Bombycilla cedrorum which nested in August/September. Foraging was the most important activity for most species in all months (7/10 species in May, 6/8 species in June, 4/8 species in July, 5/8 August/September). Few¯edgling young were observed. Most species used ®eld edges consistently more often than expected in corn and soybean ®elds, according to the edge/interior ratio, Yellow Warbler Dendroica petechia being the exception. In apple orchards, relatively few species differentiated between edge and interior. Based on their frequency of occurrence (>50%), behaviour and temporal coincidence with pesticide applications, 13 species were considered most at risk: Killdeer Charadrius vociferus, Horned Lark Eremophila alpestris, American Crow Corvus brachyrhynchos, American Robin Turdus migratorius, European Starling Sturnus vulgaris, Chipping Sparrow, Vesper Sparrow Pooecetes gramineus, Savannah Sparrow Passerculus sandwichensis, Song Sparrow Melospiza melodia, Red-winged Blackbird Agelaius phoeniceus, Common Grackle Quiscalus quiscala, Brown-headed Cowbird Molothrus ater and Barn Swallow Hirundo rustica. The latter species, because of its foraging habit, is less likely to be exposed to pesticides. This study was important to identify focal species that can be used for detailed investigations on exposure to pesticides.

Propaquizafop absorption, translocation, metabolism, and effects on acetyl-CoA carboxylase (ACCase) isoforms were examined in chickpea (Cicer arientinum L.). Maximum foliar absorption of propaquizafop, approximately 35% of recovered herbicide, occurred 48 h after treatment. Of the absorbed propaquizafop, approximately 30% was rapidly metabolized to the acid form followed by a slow conversion of the acid to a polar metabolite. Approximately 4% of foliar-applied [14C]propaquizafop was translocated from the treated leaflets within 72 h after application. Chloroplast stromal and cytosolic fractions were isolated from chickpea leaves. Proteins from both fractions were separated by SDS–PAGE and probed with avidin–alkaline phosphatase to detect biotinylated polypeptides. The cytosolic fraction contained a multifunctional ACCase as indicated by the presence of a biotinylated polypeptide of 200 kDa. The chloroplast stromal fraction contained the 36-kDa biotinylated subunit of the multi-subunit ACCase and a 200-kDa biotinylated protein which suggested the presence of a plastid-localized multifunctional ACCase. Pretreating isolated chloroplasts with thermolysin prior to lysis did not reduce the presence of the 200-kDa biotinylated protein. ACCase activity in both cytosolic and stromal fractions exhibited a high level of tolerance to propaquizafop acid and other graminicides. Total ACCase activity in the chickpea chloroplast stroma fraction appears to be composed of activities contributed by both multisubunit and multifunctional ACCases.

Monoclonal antibodies (MAbs) to the pesticide propoxur were produced from haptens with carboxylic spacer arms of different lengths introduced at the carbamate group of the analyte structure. MAbs were subsequently characterized in the conjugate-coated format using these immunizing haptens and newly synthesized compounds as homologous and heterologous assay conjugates, respectively. Appropriate combinations of immunoreagents resulted in competitive enzyme immunoassays (ELISA) with I 50 values in the low nanomolar range (6.5-17.9 nM). A modification of the conjugatecoated format consisting of the simultaneous incubation of the MAb and the peroxidase-labeled secondary antibody in the presence of the analyte resulted in an assay with an I 50 value of 4.4 nM. This one-step conjugate-coated ELISA format is as simple and fast as the antibody-coated format but without the need of synthesizing enzyme-hapten conjugates. Major N-methylcarbamate pesticides were not recognized by the MAb. This immunoassay should reasonably allow the rapid, low-cost, and sensitive determination of propoxur in food, soils, and the environment at levels of regulatory and practical importance.