Endosulfan In Water Research Articles

Removal of organochlorine insecticide endosulfan in water and soil by Fenton reaction with ascorbic acid and various iron resources.

An assortment of Fenton (or Fenton-like) reaction treatment systems using various iron resources such as ferrous sulfate, ferric nitrate, commercial zerovalent iron (mZVI), or self-made ZVI (Fe-nanowire) were evaluated to effectively remove α- and β-isomers of endosulfan (ED) from contaminated water and soil. Ascorbic acid (AA) was added as a chelation reagent to maintain the aqueous reaction of soluble iron. In the aqueous experiment, a combined treatment of 1% mZVI, 0.01 M AA, and 0.1 M H2O2 was determined to be the most effective method, showing 98-100% of ED removal within 24 h. The mZVI/AA/H2O2 treatment method was finally applied to ED-contaminated soil samples, and the application removed significant ED residues from both soil slurries (65-73%) and immobile soils containing small amount of moisture (64-66.2%). Overall results showed that the mZVI/AA/H2O2 treatment can be utilized as a potential technique to remediate both water and soil contaminated with ED.

Nationwide levels and distribution of endosulfan in air, soil, water, and sediment in South Korea

We investigated the levels and distribution patterns of α- and β-endosulfan and endosulfan sulfate in air, soil, water, and sediment samples collected from the South Korean persistent organic pollutants (POPs) monitoring networks. In the air samples, the highest concentrations of the total (Σ3) endosulfan (50.3–611 pg/m3, mean: 274 pg/m3) were observed during summer. Spearman analysis revealed a good correlation between agricultural land area and atmospheric concentrations of Σ3 endosulfan except during winter. Regardless of the season, the ratio of the two isomers (α/β) was 3.6–4.9 in the air samples, higher than that observed in technical mixtures (2.0–2.3), possibly due to the higher volatility of α-endosulfan, compared to β-endosulfan. Concentrations of Σ3 endosulfan in the soil samples (n.d.−13.4 ng/g, mean: 0.8 ng/g) were not significantly different except at some stations adjacent to large areas of farmland. The average levels of Σ3 endosulfan in the water and sediment samples were 2.1 ng/L and 0.1 ng/g dw, respectively. In analyzing the four largest rivers, it was observed that a few water stations during spring and fall and sediment stations in fall had high concentrations of the two isomers and endosulfan sulfate, particularly around the Yeoungsan and Nakdong Rivers near large areas of agricultural land. Endosulfan sulfate was dominant at most water and sediment sampling stations. This study demonstrates that the endosulfan found in most environmental compartments most probably derives from agricultural areas despite its ban as a pesticide. On the other hand, given that it was also detected in industrial and urban areas, in which pesticide application does not occur, it can be conjectured that endosulfan is aerially transported at higher temperatures and continuously circulates within the environment.

Occurrence and Distribution of Endosulfan in Water, Sediment, and Fish Tissue: An Ecological Assessment of Protected Lands in South Florida

Over the past 30 years, endosulfan, one of the last polychlorinated pesticides still in use, has received considerable attention and has been the subject of a number of international regulations and restriction action plans worldwide. This study aimed to monitor the presence and to assess the potential transport of endosulfan within the protected areas of Everglades National Park, Biscayne National Park, and Big Cypress National Preserve, South Florida, USA. Endosulfan sulfate was the major metabolite detected in all matrices in areas along the C-111 and C-111E canals, which drain the Homestead agricultural area and discharge to either Florida or Biscayne Bays, both of which are critical wildlife habitats. Endosulfan concentrations of up to 158 ng L(-1) and 57 ng g(-1) were observed in surface water and sediments, respectively, which exceeded the U.S. EPA's chronic water quality criteria (56 ng L(-1)). Elevated levels of up to 371 ng g(-1) of endosulfan sulfate were detected in whole fish tissue.

Remediation of Endosulfan by Biotic and Abiotic Methods

Endosulfan is a persistent, toxic broad-spectrum organochlorine insecticide and acaricide used on food and non-food crops. To overcome the problem of hydrophobicity of endosulfan, surfactants play a major role in soil remediation. A concentration of 1 g/L tween 80 released 83.89% ± 1.22% of endosulfan from the soil in 24 hours and a total of only 13.96% ± 0.14% was found remaining in the soil. Phytoremediation is an emerging technology that promises effective and inexpensive cleanup of contaminated hazardous waste sites. The potential of aquatic plant species Salvinia molesta and the terrestrial plant species, Spinach (Spinacia oleracea) and Tomato (Solanum lycopersicum), to remove persistent organochlorine pesticide endosulfan from contaminated water and soil respectively were investigated. Remediation of endosulfan in water using different aquatic plants showed that Salvinia molesta is more efficient in endosulfan removal as the percentage removal of endosulfan obtained was 97.94% ± 0.33% in 21 days (with an initial concentration of 123 μg/L endosulfan). Among the selected terrestrial plant species, Spinach and Tomato, percentage removal of endosulfan was found to be higher with tomato. On Day 21, complete removal of pesticide (with an initial concentration of 140 μg/Kg endosulfan) occurred in the soil in which phytoremediation was done with tomato while spinach took about 28 days for complete removal of endosulfan. Microbial degradation offers an effective approach to remove toxicants from the environment. Microbial degradation of endosulfan was studied and Pseudomonas species was able to completely degrade endosulfan in 16 days. The technologies developed can be utilized for the complete removal of endosulfan from a contaminated area. The surfactant enhanced recovery and phytoremediation will help to decontaminate the polluted water and soil. The recovered endosulfan in the surfactants and plants can be subjected to biodegradation by bacterial species using a bio reactor.

Rapid detection of endosulfan by a molecularly imprinted polymer microsphere modified quartz crystal microbalance

A highly selective and sensitive quartz crystal microbalance (QCM) fabricated by mixing with polyvinyl chloride and molecularly imprinted polymer microspheres (MIPMs) immobilized in situ on a piezoelectric quartz crystal (PQC) chip as a recognition element for rapid endosulfan detection in drinking water and milk samples. Based on our previous studies, we investigated the performances of the MIPMs in situ modified QCM (MIPMs-QCM). The surface microstructure of the uniform mono-layer MIPMs on a PQC chip was characterized by scanning electron microscope (SEM). It remained relatively stable within 10–20 min. The specificity of the MIPMs-QCM was also investigated by using a series of concentrations of endosulfan and structurally related analogs, which showed good selectivity and specificity for the recognition of endosulfan. Analysis by MIPMs-QCM sensor responded in the presence of different concentrations of endosulfan and demonstrated a good linear correlation over 10 to 40 ng mL−1 (y (Hz) = 30.83lg x (ng mL−1) − 26.32, R = 0.9856), and 40 to 1280 ng mL−1 (y (Hz) = 93.79lg x (ng mL−1) − 120.40, R = 0.9980), respectively. The lowest detection limit (LDL) was 5.59 ng mL−1 (S/N = 3). It could be repeated six times and stored for 6 months. Detection of endosulfan in water and milk samples was observed with recoveries of 96.0–104.1% and 101.8–108.0% respectively. The developed MIPMs-QCM is a reliable method for analysis of endosulfan with simple operation, good selectivity, and is inexpensive and reusable.

Current‐use pesticide transport to Costa Rica's high‐altitude tropical cloud forest

To gain insight into the atmospheric transport and deposition of organic contaminants in high-altitude forests in the humid tropics, pesticides were analyzed in air, water, and soil samples from Costa Rica. Passive samplers deployed across the country revealed annually averaged air concentrations of chlorothalonil, endosulfan, and pendimethalin that were higher in areas with intensive agricultural activities than in more remote areas. Atmospheric concentrations were particularly high in the intensively cultivated central valley. Only endosulfan and its degradation products were found in soils sampled along an altitudinal transect on the northern side of Volcano Turrialba, which is facing heavily cultivated coastal plains. Consistent with calculations of cold trapping in tropical mountains, concentrations of endosulfan sulfate increased with altitude. Pesticide levels in lake, creek, fog, and arboreal water samples from high-elevation cloud forests were generally below 10 ng · L(-1). Endosulfan sulfate was the most abundant pesticide in water, with concentrations ranging from 0.4 to 9.4 ng · L(-1). Its levels were highest in water sampled from bromeliads. Levels of total endosulfan in water are much lower than the reported median lethal concentration (LC50) value for acute toxicity of α-endosulfan to tadpoles. Although this suggests that the presence of pesticide might not have a direct impact on amphibian populations, the possibility of effects of chronic exposure to a mixture of substances cannot be excluded. Fog was relatively enriched in some of the analyzed pesticides, such as dacthal and chlorothalonil, and may constitute an important deposition pathway to high-altitude tropical cloud forest.

Environmental impact of insecticides applied on biotech soybean crops in relation to the distance from aquatic ecosystems

Aquatic environments located in areas cultivated with biotech soybean were studied. Water and sediment samples were analyzed for insecticides, acute toxicity, genotoxicity, detoxification biomarkers, and fish diversity. Samples were taken in the core area of soybean cultivation in Argentina; all measures were related to the distance between the crops and the streams sampled. Endosulfan (alpha + beta) concentrations as high as 553.33 microg/kg were found in sediments from environments located at 0.15 m from treated fields. Ethoxyresorufin-O-deethylase (EROD) activity and cytochrome P4501A1 (CYP1A1) gene expression in fish showed the highest correlation with the environmental concentration of endosulfan. These biomarkers and mortality of amphipods significantly correlated with the concentration of endosulfan in water and sediment, which correlates inversely with the distance between the crop and streams. The differences with respective controls disappear at distances greater than 5 m. The fish diversity was significantly lower from distances between the margin of the stream and soybean crops, not exceeding 2 m.

Distribution of endosulfan in water, sediment and fish from Warri river, Niger delta, Nigeria

AbstractThis article presents the first attempt to quantify the levels and distribution pattern of endosulfan, an organochlorine pesticide in surface water, sediment and fish (Chrysichthys furcatus and Tilapia zilli). The samples were collected from three stations (Ovwian, Ekakpamre and Ovu) of Warri River in the western Niger Delta of Nigeria in 2006 during the dry and wet seasons (January–August). A total of 96 samples made up of 24 samples each for water, sediment and fish were analysed in this study. The pesticide levels were analysed using high performance liquid chromatography (HPLC model CECIL 1010) to elucidate its distribution in various environmental compartments. The ranges of concentrations of the pesticide in the matrices were: 0.01–9.23 μg/l (water), 0.06–11.98 μg/gdw (sediment), 0.01–15.06 μg/gdw (Chrysichthys furcatus) and 0.01–1.80 μg/gdw (Tilapia zilli). From this result, decreasing order of occurrence of the pesticide is as follows: fish > sediment > water. The concentrations observed in fish (Chrysichthys furcatus) were higher than the levels observed in sediment and water suggesting bioaccumulation of the pesticide by the fish. Spatial variations occurred with downstream stations having statistically higher concentrations in all matrices at P < 0.05. Seasonal variations occurred with higher concentrations in dry season for water and sediment only, while the fish species had higher concentrations in the wet season. The observed values of endosulfan were above the ecological bench marks (0.02 μg/l) recommended by Nigeria Environmental Protection Agency and European Union. They were also relatively higher than those in previous studies on the Nigerian environment, an observation that calls for regular monitoring of the Niger Delta water bodies.

Spectrophotometric Determination of Endosulfan Using Thionin and Methylene Blue as Chromogenic Reagents

A simple, selective and sensitive spectrophotometric method is proposed for the determination of widely used organochlorine pesticide endosulfan using thionin and methylene blue as chromogenic reagents. The method is based on the liberation of sulfur dioxide from endosulfan by adding acid reagent and alcoholic potassium hydroxide. The liberated sulfur dioxide is passed through potassium iodate solution and the iodine so liberated bleaches the violet color of thionin and blue color of methylene blue and is measured at 600 nm and 665 nm respectively. This decrease in absorbance is directly proportional to the endosulfan concentration. The Beer's law is obeyed in the range of 0.4-7.0 and 0.2-9.0 microg mL(-1) of endosulfan using thionin and methylene blue as reagents respectively. The molar absorptivity and Sandell's sensitivity were found to be 1.05 x 10(5) and 5.03 x 10(4) L mol(-1) cm(-1), 3.85 x 10(-3) and 8.10 x 10(-3) microg cm(-2) of endosulfan using thionin and methylene blue as reagents respectively. The method has been applied for the determination of endosulfan in water, soil and vegetables.

The Fate of Endosulfan in Water

Although the use of endosulfan to control cotton pests has declined, this insecticide still has widespread application in agriculture and can contaminate riverine systems as runoff from soil or by aerial deposition. The degradation of endosulfan in pure water at different pH values of 5, 7 and 9 and in river water from the Namoi and the Hawkesbury rivers of New South Wales (NSW), Australia, was studied in the laboratory. Endosulfan transformation into endosulfan sulfate in river water using artificial mesocosms was also investigated. The results show endosulfan is stable at pH 5, with increasing rates of disappearance at pH 7 and pH 9 by chemical hydrolysis. Incubation of endosulfan with river water at pH 8.3 resulted in the disappearance of endosulfan and the formation of endosulfan diol due to the alkaline pH as well as formation of endosulfan sulfate. Although the degradation of endosulfan by Anabaena, a blue-green alga, did not result in the transformation of endosulfan to endosulfan sulfate, we conclude that other microorganisms catalyzed the formation of the sulfate. Significant conversions of endosulfan into endosulfan sulfate were also reported from associated field studies using artificial mesocoms containing irrigation water from rivers inhabitated by micro-macro fauna. From these results, we conclude that the presence of endosulfan sulfate in river water cannot be used to distinguish contamination by runoff from soil from contamination by aerial drift or redeposition.

Fate and toxicity of endosulfan in Namoi River water and bottom sediment.

Endosulfan (6,7,8,9,10,10,-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepine-3-oxide) sorption (standardized to 1% total organic carbon and dry weight) was significantly (P < 0.05) more concentrated on the large (>63 microm) particle fraction compared with smaller size fractions (<5 microm and 5-24 microm) of bottom sediments from the Namoi River, Australia. Following completion of the particle size fractionation (6 to 12 wk) and a sediment toxicity assessment (2 wk), the sediments showed large decreases in concentrations of alpha-endosulfan that coincided with an increase in endosulfan sulfate concentrations and minimal changes in beta-endosulfan concentrations. In the Namoi River, similar patterns were observed in the composition of total endosulfan in monthly measurements of bottom sediments and in passive samplers placed in the water column following runoff from cotton (Gossypium hirsutum L.) fields. The toxicity of endosulfan sulfate in river water indicated by the nymphs of the epibenthic mayfly Jappa kutera, was more persistent than the alpha- and beta-endosulfan parent isomers due to its longer half-life. This suggests that endosulfan sulfate would contribute most to previously observed changes in population densities of aquatic biota. Measured concentrations of total endosulfan in river water of up to 4 microg L(-1) following storm runoff, exceed the range of the 96-h median lethal concentration (LC50) values in river water for both alpha-endosulfan (LC50 = 0.7 microg L(-1); 95% confidence interval [CI] = 0.5 to 1.1) and endosulfan sulfate (LC50 = 1.2 microg L(-1); 95% CI = 0.4 to 3.3). In contrast, the 10-d LC50 value for total endosulfan in the sediment toxicity test (LC50 = 162 microg kg(-1); 95% CI = 120 to 218 microg kg(-1)) was more than threefold higher than the highest measured concentration of total endosulfan in field samples of bottom sediment (48 microg kg(-1)). This suggests that pulse exposures of endosulfan in the water column following storm runoff may be more acutely toxic to riverine biota than in contaminated bottom sediment.

Application of C18 disks followed by gas chromatography techniques to degradation kinetics, stability and monitoring of endosulfan in water

A comparative degradation study of endosulfan spiked at 35 μg/l in water using photocatalysis with (FeCl3/H2O2)/(TiO2/H2O2) and photolysis using either a xenon arc lamp and/or sunlight was performed. After irradiation the water samples were preconcentrated using C18 solid-phase disk extraction and analysis by gas chromatography–electron capture and mass spectrometric detection. Endosulfan sulphate was found in the photodegradation studies. Endosulfan showed high stability in water when it was exposed to sunlight and xenon arc lamp, but by means of photocatalysis with FeCl3/H2O2, TiO2/H2O2, the degradation was very fast with half lives varying from 59–98 min. The degradation kinetics followed a first order reaction and the R.S.D. of rate constants, for n=3, varied from 4–17%. The stability of endosulfan on C18 Empore disks has been determined at 20°C, 4°C and −20°C for periods up to 3 months. Endosulfan was not degraded on C18 Empore disks. Ground water samples from south of Spain (Almeria) were monitored during 1 year. The compounds α-, β- and endosulfan sulphate were detected at concentration values varying from 0.5–540 ng/l.

Hapten synthesis and development of ELISAs for detection of endosulfan in water and soil.

Two enzyme immunoassays, a laboratory assay based on microwell plates and a field test based on the use of small polystyrene tubes, have been developed for the detection of endosulfan (1,4,5,6,7,7-hexachloro-8,9,10-trinorborn-5-en-2,3-ylenedimethyl sulfite) residues in water and soil. To raise antibodies that are sensitive and selective for the toxic forms of endosulfan, three haptens were prepared. One hapten was prepared by derivatization of endosulfan diol [1,4,5,6,7,7-hexachloro-2,3-bis(hydroxymethyl)norborn-5-ene], while the others used derivatives of a rigid five-membered ring adjacent to the bridged hexachlorocyclopentadiene (cyclodiene) ring. Different hapten combinations were used for immunogen and reporter enzyme conjugate in both the microwell and field assays. The optimized assays have detection limits of about 0.2 ppb endosulfan and detect in the range 0.2-10 ppb (0.2-20 ppb for field assay, without sample dilution). Water samples can be analyzed directly without solvent extraction or concentration, while soil samples are simply extracted with 90% methanol. The tests detect endosulfan sulfate (1,4,5,6,7,7-hexachloro-8,9,10-trinorborn-5-en-2,3-ylenedimethyl sulfate) with sensitivity similar to that for endosulfan but are 4-10 times less sensitive to endosulfan diol, and therefore the assays can potentially determine toxic compounds of endosulfan (endosulfan and endosulfan sulfate) from the total endosulfan residues present in the environment.

Acute toxicity to fish of low-dose aerosol applications of endosulfan to control tsetse fly in the Okavango Delta, Botswana

Laboratory studies on Okavango fish gave 24 h LC 50 values for endosulfan ranging between 1·2 and 7·4 μg litre −1, depending on species. In the field, concentrations of endosulfan in water 6–9 h after spraying 9·5 ha −1 ranged between 0·2 and 4·2 μg litre −1; in shallow water concentrations fell to undetectable levels (<0·025 μglitre −1) within 5 days but remained detectable for up to 20 days in deeper water. Experiments using tanks and cages in the field indicated that the presence of submerged aquatic vegetation and silt was correlated with lower concentrations of endosulfan. Apparent mortality of fish in the field ranged between 0 and 60%, was sporadic, localised and varied between species. Residue samples from aluminium foil sheets indicated uneven deposition of insecticide, and improvements to spraying techniques have been suggested that might reduce fish kills.