Phosphate Pesticides Research Articles

Pollution of surface waters with phosphates and heavy metals

It is substantiated that the current ecological state of the surface waters of Ukraine is characterized by very dirty. The research results indicate that insufficiently treated wastewater enters surface sources. The main pollutants include phosphates as a constituent of detergents, washout of phosphate fertilizers and pesticides from agricultural communities, and industrial effluents containing heavy metals. The analysis of modern data on the sources and intensity of entry, content, transformation and influence of phosphates and heavy metals on aquatic organisms and surface water bodies was carried out. It is emphasized that an excess of phosphorus compounds leads to the development of eutrophication in water bodies. It is shown that heavy metals belong to the group of the most dangerous toxic substances entering aquatic ecosystems, mainly as a result of technogenic action. In terms of toxicity, they are second only to pesticides. Unlike organic pollution, heavy metals are elements that do not undergo destruction in the aquatic ecosystem, but are only distributed among its components. A scheme of the intensity of pollution of individual components of the biosphere is given. Modern methods of water treatment both from phosphates and from heavy metal ions, which have their own advantages and disadvantages, are considered. A scheme for reducing the level of pollution of surface waters with phosphates and heavy metals is given.

Importance of Phosphate Pesticides

demand for food grains/crops with limited expansion of the agricultural land. Pesticides are widely used in agriculture without paying much heed to the consequences of its unregulated and indiscriminate use. Detection of pesticides and their degradation products in soil water and air at relevant levels have invoked public concern and are responsible for the adverse effects of pesticides to target and non-target organisms environmentally. The persistence, bioaccumulative, and toxic nature of agrochemical is responsible for different eco-toxicity. Some pesticides last as long as the environment (like DDT, chlordane). M

Human Health Risk of Organochlorine Pesticides in Foods Grown in Nigeria.

Background.Production of foods safe for consumption is an important issue worldwide. Organochlorine pesticides (OCP) are often used to preserve crops. Their use can have serious impacts on human health.Objectives.This research aims at assessing OCP residues in food samples from markets in Lagos in southwestern Nigeria and their risk to human health.Methods.Sixteen food samples were collected from Lagos, Nigeria and analyzed for organochlorine pesticide residues. Extraction was performed using an ultrasonicator, and analysis was carried out using a gas chromatograph-electron capture detector. Risk assessment was carried out by determining the hazard quotient.Results.Results of the OCP residues found in the foods were generally low, with dichlorodiphenyldichloroethylene (p,p'-DDE) having the highest residue concentration. The concentration of p,p'-DDE was as high as 110 ng/g in pulses and 123 ng/g in Cameroon and chili peppers. The risk index was <1 in most cases, with the exception of dichlorodiphenyldichloroethane (p,p'-DDD) in fruits for children.Discussion.The results were generally lower than what has been documented in other parts of the world and suggest that consumption of the foods investigated in the present study in Nigeria may be considered safe for the 13 OCPs investigated.Conclusions.There is a need for continuous monitoring of these OCPs and investigation of carbamate and phosphate pesticide residues since they are more widely used in farming practices in Nigeria.

Urinary organophosphate metabolite levels in Palestinian pregnant women: results of the Middle East Regional Cooperation Project

The purpose of the study was to measure urinary organophosphate (OP) metabolites in Palestinian pregnant women, and to compare levels with those in pregnant women in Jerusalem and women from the general population in Israel. We measured six dialkyl phosphates in urine samples collected from 148 pregnant women from the West Bank area. Median total dimethyl phosphate (DMtotal) levels were significantly lower in Palestinian women compared to Jerusalem pregnant women and women in Israel (p = 0.041). In Palestinian women reporting that their place of residence was near an agricultural field, DMtotal levels were significantly higher (p = 0.037). Lower urinary excretion of dimethyl phosphate pesticide metabolites in Palestinian women compared to Israeli women may result from lower consumption of fruits and vegetables in the Palestinian population. Our findings highlight differences in OP pesticide exposure in populations with close geographical proximity but with differences in culture, diet, lifestyle, and regulatory oversight of pesticides.

Physicochemical standardization and evaluation of in-vitro antioxidant activity of Aconitum heterophyllum Wall

ObjectiveTo evaluate different physicochemical parameters and in-vitro antioxidant activity of Aconitum heterophyllum (A. heterophyllum), having great medicinal value in treatment of diseases associated to nervous system, digestive system, rheumatism, fever and also in case of bacterial, viral and fungal infections. MethodsVarious physicochemical parameters such as extractive values, haemolytic activity, foaming index, swelling index, heavy metal analysis and pesticide content as per the guidelines of WHO were included. Determination of starch grains, crude fiber, fluorescence powder drug analysis and preliminary phytochemical analysis of root of A. heterophyllum were also included. Various phytoconstituents such as total phenols, tannins, flavonoids, flavonols, alkaloids and saponins were quantified in the present study. The ethanolic extract was further screened for in-vitro antioxidant activity using different models. ResultsThe result depicted a higher extractive value in case of aqueous extract which decreased as the polarity decreased. The haemolytic activity of A. heterophyllum was found to be 212.5 units/g of plant material while chlorinated and phosphate pesticides along with heavy metals were found to be within the standard limits of WHO. The quantitative estimations demonstrated the root to be highly rich in alkaloids while phenols, tannins, flavonoids and saponins were found in less quantity. The in-vitro antioxidant study showed a moderate to low activity in all models which may be attributed to low phenolic and flavonoid content. ConclusionThe valuable information provided in the study will ascertain the identity and authenticity of A. heterophyllum and will help in maintaining quality and purity thus, preventing its adulteration.

Monitoring of cholinesterase-inhibiting activity in water from the Tone canal, Japan, as a biomarker of ecotoxicity

The cholinesterase (ChE)-inhibiting activity of water and the concentrations of representative inhibitors were monitored in the Tone canal, Japan, during April to December 2006. The ChE-inhibiting activity, measured by using horse serum as enzyme source, increased from late April to early June, and from September to October. Although the trends in the ChE-inhibiting activity of the samples were consistent with concentration changes of organophosphorus pesticides, ChE-inhibiting activity was not observed in samples replicated on the basis of the chemical concentrations detected. The water samples were treated with chlorine to enhance the ChE-inhibiting activity by conversion of thiophosphate pesticides to phosphate pesticides. The ChE-inhibiting activity increased in almost all the chlorine-treated samples, although organophosphorus pesticides were either not detected or detected in traces in the samples by gas chromatographic-mass spectrometric analysis. These results suggested that assay of ChE-inhibiting activity is important for evaluating the ecotoxicity of environmental water, because toxicological investigations based solely on inhibitor concentrations may underestimate the contamination. Furthermore, the combined method of oxidation by chlorination and the ChE assay is very effective for screening and monitoring of organophosphorus pesticides in environmental water.

Novel Piezoelectric DDVP Sensor Based on Self‐Assembly Method

A novel piezoelectric sensor was fabricated by depositing the films of polyvinyl pyrrolindone (PVP) and PVP with butyl cholinesterase (BuChE) (BuChE‐PVP), respectively, on the surface of quartz crystal microbalance (QCM) using self‐assembly method. The sensitive films were characterized with online examination and XPS technique. The obtained sensors were applied to measure o,o‐dimethyl‐o‐2,2‐dichlorovinyl phosphate (DDVP) pesticide concentration. It shows that BuChE‐PVP sensor has higher sensitivity than PVP sensor. There is a linear relationship between the shift of frequency and the concentration of DDVP in a range from 4.25 to 21.25 ppm. This highly sensitive sensor has also been shown to determine DDVP concentration in several samples, and the relative standard error is less than 3%. It also shows that CO, NO2, H2S, and SO2 with 10 times the concentration of DDVP have no interference with DDVP detection in the tested concentration range.

Clinical observation of the effect of different medication to phosphate pesticide intoxation patients

目的 探讨有机磷农药中毒患者不同给药方法与临床治疗护理效果的关系.方法将186例有机磷农药中毒患者随机分为3组A组、B组、C组.静脉推注给药(A组)113例,微量泵给药(B组)26例,先静脉推注达阿托品化后微量泵给药(C组)47例,对3组进行比较.主要评价内容为阿托品化时间、给药次数、平均住院天数.结果A组给药次数明显多于其他2组(P＜0.05);B组阿托品化时间明显延长(P＜0.05),且平均住院天数也延长(P＜0.05),有统计学意义.结论有机磷农药中毒患者采用静脉推注达阿托品化后微量泵给药,既能快速达到阿托品化,减少给药次数,缩短平均住院天数,又能保持血药浓度稳定,生命体征波动范围小,有利于治疗与护理效果的提高,值得临床推广。

The nematode Caenorhabditis elegans as a model of organophosphate-induced mammalian neurotoxicity

Fifteen organic phosphate pesticides were tested by computer tracking for their acute behavioral toxicity with the nematode Caenorhabditis elegans. Thirteen of these 15 chemicals are used as insecticides and are anticholesterase agents. The other two chemicals are used as herbicides. EC50 values for each chemical were compared to the corresponding LD50 acute lethality value in rats and mice. Order of toxicity was found to be significantly correlated in comparisons of C. elegans to both rats and mice. Mechanistic investigations were conducted by assaying 8 of the 15 chemicals for anticholinesterase activity in C. elegans. Significant cholinesterase inhibition was confirmed for five chemicals that had displayed high behavioral toxicity, while three chemicals of low behavioral toxicity showed no significant decrease in cholinesterase activity. Toxicity for two chemicals that do not inhibit cholinesterase in mammals was linked to pH effects. Detailed comparison of individual chemicals and metabolic issues are discussed. These results have positive implications for the use of C. elegans as a mammalian neurological model and support the use of C. elegans in early rounds of chemical toxicity screening.

Decomposition of phorate in aqueous solution by photolytic ozonation

The degradation of phorate, a highly toxic organic phosphate pesticide, in aqueous solution by photolytic ozonation was studied under various experimental conditions. The rate constants of phorate decomposition and formation of various anions by photolytic ozonation were roughly independent of the solution's pH value. The initial step of the photolytic decomposition of phorate is considered to be the breakage and subsequent oxidation of the PS double bond on the phorate molecule, followed by isomerization and consequent oxidation of various organic intermediates.

The natural enrichment of ferruginous weathering products and its implication for water quality in the Hunchun Basin, China

In order to evaluate the extent of a natural enrichment of Fe and Mn over the whole of the Hunchun Basin, the stability of Fe-Mn mineral phases, their status, the weathering rate of source materials, and soil characteristics were determined. A variety of samples were collected from sediments, soil profiles, and surface soils. In the solutions after a sequentially selective dissolution using sodium pyrophosphate (p), acid oxalate (o), and dithionite-citrate-bicarbonate (d), Si, Al and Fe were dominant in the d and p fractions, and Mn in the o and p fractions. The results showed that the existing phases and status of Fe and Mn were distinctly different, and that the abundance of amorphous Mn phases made thermodynamic calculation difficult. An application of these ferruginous weathering products was therefore made to understand basin development. The first terrace of the Hunchun River is more active than the second terrace, which can be inferred from it having a higher value in Fe d /Fe t . Amorphous Fe phases such as Fe(OH)3 and Fe3(OH)8 were controlling factors of Fe in the thermodynamic calculations. The transformation of the amorphous Fe phases to more stable phases was hindered by high contents of smectite and gibbsite, amorphous opaline produced from rice roots, and organic phosphate pesticides or fertilizers in soils. Source-rock deduction using water samples suggested granitic weathering. Precipitation around the Hunchun Basin is gradually becoming more acidic. Therefore, in the future it is inevitable that ecological and environmental problems related to the Fe phases mentioned above will occur in the drinking water supply for this area, especially in that of the first terrace.

Accumulation of Trace Metals in the Lichen Evernia prunastri Transplanted at Biomonitoring Sites in Central Italy

Samples of the epiphytic lichen Evernia prunastri collected in an unpolluted area were transplanted to the urban environment of Teramo (central Italy). The influence of the transplant process on trace element content was found to be negligible and after only two months, concentrations of all elements (Cd, Cr, Cu, Pb, and Zn) were significantly higher than in control samples. It is suggested that motor traffic was the main source of atmospheric Cr, Cu, and Pb, while for Cd and Zn additional sources from phosphate fertilizers and pesticides used in the surrounding farmlands are hypothesized. The possible uptake and accumulation processes of these metals in relation to time of exposure are discussed. Lichens are known for their ability to accumulate airborne substances in concentrations far greater than those in the atmosphere (Nieboer & Richardson 1981). Accumulation at ion exchange sites and particulate trapping are two well documented mechanisms by which elevated levels of elements are achieved in lichens (Nieboer et al. 1978). Metal cations bind to extracellular anion exchange sites in the cell wall and on the plasma membrane surface (Brown & Beckett 1985). Because cell wall-bound elements are readily exchangeable, extracellular quantities and proportions reflect recent environmental inputs (Brown 1987). However, when elements occur in insoluble particulate matter, they cannot be exchanged through the cell wall and accumulate in the thallus in relation to the environmental availability of the particles and exposure time i.e., lichen age (Brown 1987). This last point was documented by Bargagli et al. (1987), who found that the central (older) part of the thallus of foliose lichens has higher concentrations of certain metals than the peripheral (younger) part. However, elements present in trapped particulates may be dissolved in water or solubilized by the lichen to some degree, and metal ions released by this process may have several fates e.g., become potentially capable of occupying cation bind sites in the cell wall or be taken up intracellularly (Kershaw 1985). According to Loppi et al. (1997), elements of limited metabolic significance (e.g., Al, Pb) have higher concentrations in the central parts, where they are presumably trapped in the medulla, whereas e ements essential for lichen metabolism (e.g., Co, Mo, Zn) have higher concentrations in the peripheral parts, but are easily displaced from one part of the thallus to another. Nevertheless, the different me abolic fates of the various metals suggest that lichens may selectively accumulate those elements that remain extracellular, whereas those elements that enter into the cell may be metabolized and eliminated or may lead to death of the lichen (Kershaw 1985). In the present paper, the results of a transplant experiment with Evernia prunastri are reported. The objective of the study is to investigate the uptake over time of Cd, Cr, Cu, Pb, and Zn after lichen samples were transplanted to an urban envi-

Chromosomal anomalies induced by the organic phospahte pesticide guthion in chinese hamster cells.

Chromosomal anomalies associated with the use of the organic phosphate pesticide guthion were investigated in Chinese hamster cells (line CHO-K1). Most commonly observed were chromatid breaks and exchanges. Infrequently, mild failure of condensation, despiralization, secondary constriction, gaps, pulverization, ring and dicentric chromosomes were noted. The mean number of chromosome breaks per cell was significantly higher in treated cells than in control cells. Autoradiographic studies revealed that while higher dosages of the chemical (80–120 μg/ml) arrested cells and prevented their movement out of S phase, a lower dosage (60 μg/ml) caused a progression delay. In relation to the relative length of no. 1 and no. 2 chromosomes, no apparent difference existed in the incidence of total breaks between them. However, significant differences in the nonrandom distribution of breaks in no. 1 and no. 2 chromosomes indicated linear differentiation of breakage susceptibility along the chromosomes. An increased concentration of breaks was observed in the long arms of both no. 1 and no. 2 chromosomes. The experimental results suggest that guthion, as well as inducing chromosomal anomalies, may produce a viable mutant.

The effect of a sublethal concentration of LAS on the acute toxicity of various phosphate pesticides to the fathead minnow (Pimephales promelas Rafinesque)

The effect of a sublethal concentration of LAS on the acute toxicity of various phosphate pesticides to the fathead minnow (Pimephales promelas Rafinesque)

Quantitative studies of the effect of antagonists on the acute toxicity of organophosphates in rats.

1. The subcutaneous acute toxicities of the vinyl phosphate pesticides monocrotophos, dicrotophos, chlorfenvinphos, crotoxyphos, dichlorvos, mevinphos, and of the experimental compounds SD 4455 (cis-2-carboxy-1-methylvinyl dimethylphosphate) and SD 7779 (cis-2-(1-phenylethoxy) carbonyl-1-methylvinyl diethylphosphate) have been determined in female rats.2. The effects on the log dose-probit mortality curves to the vinylphosphates of the therapeutic subcutaneous administration of methylatropine, atropine, N-methylpyridinium-2-aldoxime methanesulphonate and obidoxime have been studied.3. Elevation of the LD50 values by the therapeutic regimens was shown to be an unsatisfactory measure of therapeutic efficiency, while reduction of the effect of a maximally lethal dose (LD90) to less than that of a minimally lethal dose (LD10) provided a better quantitative measure of therapeutic efficiency.4. The combination of atropine sulphate (50 mumol base/kg) with obidoxime (250 mumol/kg) was found to be generally the most effective of the antidotal regimens.

Sweep Co-Distillation Cleanup of Fortified Edible Oils for Determination of Organophosphate and Chlorinated Hydrocarbon Pesticides

Abstract The technique of sweep co-distillation developed for organophosphate pesticides in fruits and vegetables was expanded for application to organophosphate and chlorinated hydrocarbon pesticides in edible oils. A modified longer and wider Storherr tube and heating assembly was used in this work and 3 mm diameter glass beads replaced the glass wool packing used in crop work. The work on oils was performed at 248 ± 3°C with a nitrogen flow of 600 ml/min and injection of a sweeping solvent every 3 minutes for 30 minutes. Phosphate pesticides were analyzed by GLC with a potassium thermionic detector and chlorinated pesticides were determined by ECGLC, after a micro Florisil column was used to eliminate extraneous peaks. Recoveries of ten phosphate pesticides from nine edible oils ranged from 74 to 100% at fortification levels of 0.04 to 6.25 ppm; average recoveries for the individual pesticides were 90—99%. Average recoveries for the chlorinated pesticides ranged from a low of 75% for Tedion to a high of 98% for endrin and dieldrin. Sensitivity of 0.01 is readily obtainable for compounds such as parathion and heptachlor cpoxide. The sweep co-distillation method is suitable for the rapid determination of the 14 chlorinated and 10 organophosphate pesticides tested in edible oils

Catalytic hydrolysis of some organic phosphate pesticides by copper(II)

Catalytic hydrolysis of some organic phosphate pesticides by copper(II)

Response Characteristics of a New High Temperature Electron Capture Detector

Abstract An electron capture detector, which uses Ni63 as its radioactive source and whose design features permit operation up to 300°C, has been developed and tested. This detector exhibits essentially the same electron capture characteristics as a parallel plate detector using tritium, but it does not lose its activity when operated above 200°C. Continuous operation of this detector for 6 months at 300°C did not change its response pattern to a variety of organohalide and phosphate pesticides. Maintenance of this response integrity over a 6-month span shows that this detector is a considerable improvement over existing systems for routine quantitative gas chromatography of pesticide residvies.

An Approach to the Separation, Identification, and Determination of at Least Ten Organophosphate Pesticide Residues in Raw Agricultural Products

Abstract This paper describes the preliminary development of a method that permits relatively rapid qualitative determination of residues of a number of common phosphate pesticide compounds. Extraction is followed by vacuum sublimation, gas-liquid chromatography, and infrared analysis. A wide variety of vegetables and fruits can be analyzed by the general procedure.

The separation and detection of organo phosphate pesticides using diphasic paper chromatography

The separation and detection of organo phosphate pesticides using diphasic paper chromatography