Pesticide Concentrations In Water Research Articles

Exploring the relationship between land-use and pesticides in freshwater ecosystem: A case study of the Araguaia River Basin, Brazil

Freshwater aquatic ecosystems are vulnerable to human activities within their surroundings, presenting a concerning scenario for aquatic organisms and human subsistence. Therefore, understanding the occurrence of pesticide contamination is a necessary condition to safeguard aquatic biodiversity and human health. We analysed the pesticide residues in water samples, using the solid-phase extraction (SPE) technique and determination by ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC‒MS/MS). We also we investigated whether land use influences water contamination by pesticides in the middle and upper Araguaia River basin, situated in the central region of Brazil in the Cerrado biome. We evaluated the effect of land use and land cover type on pesticide occurrence in nine subbasins using mixed linear models. We registered the occurrence of pesticides in all subbasins. After water analysis a total of eight pesticides were found: atrazine, carbendazim, cyanazine, imidacloprid, 2,4-D, clomazone, chlorpyrifos-ethyl, and imazalil. Atrazine and carbendazim were detected during both sampling years. The active ingredient atrazine and clomazone were registered in all studied subbasins, with concentrations ranged from 0.006–0.207 µg L−1 and 0.183–0.373 µg L−1, respectively. There were no significant relationships observed between the number of pesticides and the type of land use and land cover, a result possibly related to the short sampling period, as these pesticides are largely used for fungi and insect control in agricultural areas. The presence of pesticides in the water may have potentially detrimental effects on aquatic biodiversity because sampled pesticides have been associated with anomalies in ontogenetic development, diseases, and mortality in organisms. Based on European legislation, it was evident that most of the subbasins had pesticide concentrations in the water exceeding the safety levels for human consumption. Thus, it is crucial for Brazilian legislation to establish maximum limits for pesticide concentrations in water to ensure safe drinking water for the Brazilian population. Additionally, a permanent monitoring system should be established to understand contamination trends in this basin and to take appropriate actions to mitigate adverse impacts.

Assessing acetamiprid and chlorpyrifos pesticide concentrations in water and sediments across macadamia orchard and communal area small reservoirs

ABSTRACT Pesticides are well known for their persistence in the environment their slow degradation and high toxicity. Aquatic environments, while not the target of many pesticide applications, often receive these chemicals from their catchments through runoff dynamics. Here, we assessed pesticide concentrations of acetamiprid and chlorpyrifos in water and sediment across macadamia orchard and communal area reservoirs in the Levubu area, South Africa, using liquid chromatography tandem mass spectrometry. Analysis of acetamiprid and chlorpyrifos associated with sediments in macadamia orchard reservoirs revealed mean pesticide concentrations of 14.48 µg L−1 and 5.67 µg L−1, respectively, whereas, in communal area reservoirs both pesticides were not detected. Acetamiprid was not detected across reservoir water, whereas the mean pesticide concentration of chlorpyrifos of 6.51 µg L−1 (macadamia orchard) and 0.13 µg L−1 (communal area) were detected. Significant differences were observed for chlorpyrifos concentrations in water samples between macadamia orchard and communal area reservoirs, whereas acetamiprid and chlorpyrifos indicated non-significant differences in sediments. The results indicate that macadamia orchard reservoirs are highly contaminated by acetamiprid and chlorpyrifos. Consequently, these pesticides can alter water quality and ecosystem functioning by reducing species diversity, adjusting community structure, altering energy flow and nutrient recycling.

Методы изучения миграции пестицидов: анализ, сравнение, рекомендации по использованию при оценке риска воздействия на грунтовые воды

Groundwater pollution with pesticides has affected every country on every continent. An important challenge for researchers and regulatorу bodies in all countries is to develop methods and tools for predicting the risks to groundwater that are associated with pesticide use. In this paper, the generally accepted methods for studying pesticides migration are reviewed and analyzed from the point of view of their applicability for assessing the risk of pesticides impact on groundwater. Using examples, it is shown that the available methods may be divided into two categories, direct and indirect ones. The indirect methods (mobility indices and field studies of pesticide migration) make it possible to compare the migration ability of a pesticide molecule and to determine the depth of penetration of the pesticide into the soil. The direct methods (modeling, lysimetric studies, and monitoring) provide for the determination of pesticide concentrations in groundwater or groundwater leachate, which makes such methods useful in assessing the risk of pesticide use. Thus, by comparing the measured pesticide concentrations in water with acceptable threshold values, it is possible to determine the risk level of a pesticide. Examples of calculating the mobility indices indicate that their estimates differ from each other. Disadvantages of migration field experiments are related to analytical problems and to the short duration of a study. Modeling the migration of pesticides is an effective tool that makes it possible to quickly determine pesticides concentration of in water runoff and to identify the pesticides that can pollute groundwater under specific soil and climatic conditions. Calculations show that for 40 pesticides out of 180 licensed for use in the Russian Federation, their predicted concentrations exceed 1 µg/l. The second method that allows to directly determine concentrations in leachate is lysimetric experiments. A long-term study of the migration of 4 pesticides showed that all toxicants migrate beyond the soil profile. A third useful tool is pesticides monitoring in groundwater. Further development and dissemination of this method for controlling pesticides in groundwater is an important task for the regulatory authorities and the scientific community of the Russian Federation in the near future.

Widespread pesticide contamination of drinking water and impact on cancer risk in Brazil.

Pesticides, which are associated with endocrine dysfunction, immunological dysregulation, and cancer, are widespread sources of drinking water contamination. The state of Paraná has a population of 11 million, is the second largest grain producer in Brazil and is a leading consumer of pesticides. In this study, we analyzed the extent of drinking water contamination from 11 proven, probable, or potentially carcinogenic pesticides (alachlor, aldrin-dieldrin, atrazine, chlordane, DDT-DDD-DDE, diuron, glyphosate-AMPA, lindane-γ-HCH, mancozeb-ETU, molinate, and trifluralin) in 127 grain-producing municipalities in the state of Paraná. Extensive contamination of drinking water was found, including legacy pesticides such as aldrin-dieldrin (mean 0.047ppb), DDT-DDD-DDE (mean: 0.07), chlordane (mean: 0.181), and lindane-HCH (mean: 2.17). Most of the municipalities were significantly above the maximum limits for each one of the currently allowed pesticides (67% for alachlor, 9.44% for atrazine, 96.85% for diuron, 100% for glyphosate-AMPA, 80.31% for mancozeb-ETU, 91.33% for molinate, and 12.6% for trifluralin). Ninety-seven percent of municipalities presented a sum of all pesticides at levels significantly above (189.84ppb) the European Union preconized limits (<0.5ppb). Using the mean pesticide concentration in water (ppb), the exposed population for each municipality, and the benchmark cancer risk for pesticides, we estimated the minimum number of cancer cases attributable to pesticide-contaminated drinking water during the period (total of 542 cases). More than 80% were attributed to mancozeb-ETU and diuron. Glyphosate-AMPA and diuron-attributable cases strongly correlated with the total cancer cases in the same period (R=0.8117 and 0.8138, respectively) as well as with breast cancer cases (R=0.7695 and 0.7551, respectively). Water contamination was significantly correlated with the sum of the estimated cancer cases for all 11 pesticides detected in each city (R=0.58 and p<0.0001). These findings reveal extensive contamination of drinking water in the state of Paraná and suggest that contamination may increase the risk of cancer in this region.

Evaluation of first and second rice cultivation based on diazinon pesticide concentration in water and soil of paddy fields of Mazandaran province

سابقه و هدف: مصرف آفت کش های ارگانوفسفره در کشاورزی، مشکلات عدیده محیط زیستی در پی دارد. آلودگی آب و خاک و بر هم خوردن تعادل‌ اکوسیستم های طبیعی، ظهور آفات و بیماری های جدید، وجود بقایای آفت کش ها در محصولات کشاورزی و عوارض بهداشتی حاصله موجب شده است که مدیریت مصرف آفت کش های آلی فسفره به عنوان یک ضرورت اجتناب ناپذیر مطرح شود. با وجود پایین بودن سرانه مصرف آفت کش ها درکشور در مقیاس جهانی، کاربرد نامطلوب آفت کش های ارگانوفسفره در برخی مناطق کشور از جمله استانهای شمالی و آلودگی های ناشی از آن، از مسائل مهم محیط زیستی کشور می باشد. در این تحقیق، با توجه به مصرف گسترده آفت کش فسفره دیازینون برای کنترل کرم ساقه خوار برنج در استان مازندران و با امعان نظر به شاخص تاثیر زیست محیطی (Environmental Impact Quotient) این آفت کش از حیث مخاطره آمیز بودن برای محیط زیست منطقه، غلظت دیازینون در آب و خاک مزارع برنج مورد بررسی قرار گرفت.مواد و روش ها: شناسایی آفت کش دیازینون در آب و خاک مزارع برنج استان مازندران با تعیین ایستگاههای ثابت برای نمونه برداری صورت گرفت. در مجموع 50 نمونه آب و خاک برای کشت اول و 30 نمونه آب و خاک در کشت دوم نمونه برداری گردید و پس از انتقال به آزمایشگاه توسط دستگاه گاز کروماتوگرافی (Gas Chromatography) مورد اندازه گیری قرار گرفت. نمونه برداری در سه فصل بهار، تابستان (قبل از نشا یا درحین برداشت محصول) و اوایل پاییز (برای کشت دوم برنج) انجام شد.نتایج و بحث: نتایج اندازه گیری انجام شده حاکی از تفاوت معنی‌دار در مقدار دیازینون در آب کشت اول در مقایسه با کشت دوم و خاک کشت اول در مقایسه با کشت دوم داشت. همچنین میانگین دیازینون در نمونه‌های آب کشت دوم نسبت به کشت اول، 7.8 برابر و در نمونه‌های خاک کشت دوم نسبت به کشت اول 1.66 برابر بود که بیانگر مقادیر بالا و هشداردهنده مصرف آفت کش دیازینون در کشت دوم برنج است. پایداری و حلالیت دیازینون و شرایط محیطی استان مازندران به ویژه بالابودن سطح آب های زیرزمینی، موجب افزایش ماندگاری این آفت کش و به تبع آن مخاطرات جدی محیط زیستی می شود. نتیجه گیری: با توجه به مقادیر غلظتی بالای آفت کش دیازینون در کشت دوم برنج، موضوع مدیریت مصرف سموم ارگانوفسفره و بهره برداری پایدار از اراضی تحت کشت با تمرکز بر ارتقای بهره وری تولید و افزایش راندمان محصول، توسعه آموزش های عمومی و تخصصی برای گروههای ذی نفع در تولید، عرضه و مصرف آفت کش های فسفره، ثبت و کاربرد این سموم بر مبنای ضریب اثر محیطی، استفاده از روش ها و فناوری های نوین برای مقابله با آفات مهم برنج، حذف و جایگزینی آفت کش پرخطر دیازینون از اهم مواردی هست که می بایست به عنوان راهبردها و سیاست های اجرایی حاصل از تحقیق مدنظر قرار گیرد.

Spatial distribution, ecological and health risk assessment of organophosphorus pesticides identified in the water of Naseri artificial wetland, Iran

Agricultural development is inevitable to meet the growing need for food. But along with this development, there are unintended and undesirable consequences for human life and the environment that need, found a solution and corrected. One of the most important adverse consequences of agricultural development is the pollution of surface and groundwater resources, which results from various factors such as soil erosion and improper use of different pesticides. This study aimed to conduct an environmental monitoring program in Naseri wetland to determine the concentrations of organophosphorus pesticides (OPPs) in water samples and also to evaluate the potential risks (ecological and health risk assessment) of these pesticides. The salting-out assisted liquid-liquid extraction method was used to extract pesticides. The residual concentrations of OPPs evaluated by gas chromatography/mass spectrometry (GC/MS). In this study, the ecological risk of OPPs calculated for wetland ecosystem, based on the acute risk quotient (RQi) formula with maximum (RQmax), mean (RQmean), and mixture (RQmix) concentrations of organophosphorus pesticides in the wetland water. Also, to assess the health risk of consuming contaminated fish with organophosphate pesticides, the potential non-carcinogenic and carcinogenic risks were determined by the hazard quotient (Index) (HQ, HI) and incremental lifetime cancer risk (ILCR) indices, respectively. The mean ± SD concentration of OPPs (Chlorpyrifos, Malathion, Ethion, Dichlorvos, Trifluralin and Diazinon) in samples of wetland water ranged from 0.14 ± 0.08 to 0.35 ± 0.12 and 0.054 ± 0.06 to 0.2 ± 0.1 (μg/L) in summer and autumn, respectively. The mean ± SD of OPPs in fish varied from 0.68 ± 0.86 to 3.94 ± 2.7 (μg/kg). Overall, the concentrations of pesticides in all water and fish samples were below the maximum residue limit (30 μg/kg) during the study period, according to the Environmental Protection Agency (EPA) and the World Health Organization (WHO). The results of acute risk quotient were in summer (RQmax = 3.49E-4 to 0.067, RQmean = 5.8E-5 to 0.029, RQmix = 0.139-0.026, 0.018-3.42E-3) and autumn (RQmax = 8E-4 to 0.051, RQmean = 7.74E-6 to 0.018 RQmix = 0.1–0.013, 6E-3- 1.5E-3). The non-carcinogenic and carcinogenic risk indexes due to fish consumption for adults and children were (HQ = 0.026-4.68E-4, HI = 0.041, ILCR = 1.7E-7) and (HQ = 1.85E-3-1.3E-5, HI = 0.041, ILCR = 5.55E-8), respectively. The risk of OPPs was generally low. But cumulative risk (pesticide mixtures), should not be ignored.

Pesticides in US Rivers: Regional differences in use, occurrence, and environmental toxicity, 2013 to 2017

Pesticides pose a threat to the environment, but because of the substantial number of compounds, a comprehensive assessment of pesticides and an evaluation of the risk that they pose to human and aquatic life is challenging. In this study, improved analytical methods were used to quantify 221 pesticide concentrations in surface waters over the time period from 2013 to 2017. Samples were collected from 74 river sites in the conterminous US (CONUS). Potential toxicity was assessed by comparing surface water pesticide concentrations to standard concentrations that are considered to have adverse effects on human health or aquatic organisms. The majority of pesticide use is related to agriculture, and agricultural production varies across the CONUS. Therefore, our results were summarized by region (Northeast, South, Midwest, West and Pacific), with the expectation that crop production differences would drive variability in pesticide use, detection frequency, and benchmark exceedance patterns. Although agricultural pesticide use was at least 2.5 times higher in the Midwest (49 kg km−2) than in any of the other four regions (Northeast, South, West, and Pacific, 3 to 21 kg km−2) and the average number of pesticides detected in the Midwest was at least 1.5 higher (n = 25) than the other four regions (n = 8 to n = 16), the potential toxicity results were more evenly distributed. At least 50% of the sites within each of the 5 regions had at least 1 chronic benchmark exceedance. Imidacloprid posed the greatest potential threat to aquatic life with a total of 245 benchmark exceedances at 60 of the 74 sites. These results show that pesticides persist in the environment beyond the site of application and expected period of use. Continued monitoring and research are needed to improve our understanding of pesticide effects on aquatic and human life.

Prevalence of neonicotinoids and sulfoxaflor in alluvial aquifers in a high corn and soybean producing region of the Midwestern United States

Neonicotinoids have been previously detected in Iowa surface waters, but less is known regarding their occurrence in groundwater. To help fill this research gap, a groundwater study was conducted in eastern Iowa and southeastern Minnesota, a corn and soybean producing area with known heavy neonicotinoid use. Neonicotinoids were studied in alluvial aquifers, a hydrogeologic setting known to be vulnerable to surface-applied contaminants. Groundwater samples were analyzed from 40 wells for six neonicotinoid compounds (acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, thiamethoxam), and sulfoxaflor. Samples were analyzed using liquid chromatography tandem mass spectrometry (LC/MS/MS) with both direct aqueous injection and solid phase extraction methods. Neonicotinoids were prevalent in the alluvial aquifers with 73% of the wells having at least one neonicotinoid detection. Clothianidin (68%, max: 391.7 ng/L) was the most commonly detected, followed by imidacloprid (43%, max: 6.7 ng/L) and thiamethoxam (3%, max: 0.2 ng/L). Acetamiprid, dinotefuran, sulfoxaflor, and thiacloprid were not detected during the study. The solid phase extraction method was more sensitive than direct aqueous injection, where only clothianidin detected in 23% of samples. SPE is the preferred method for detecting low concentrations of hydrophilic pesticides in water. This study documented that the combination of heavy chemical use overlying a hydrogeologic setting vulnerable to surface applied contaminants leads to transport of neonicotinoids into an important groundwater resource.

Removal of urban-use insecticides in a large-scale constructed wetland

Water treatment and reuse initiatives are essential to combat declining water supplies in a changing climate, especially in arid and semi-arid regions. Pollution of water resources intensifies the search for strategies to provide water for potable and non-potable reuse that mitigates detrimental ecological and human health effects. Fipronil and synthetic pyrethroids are common urban-use insecticides that exert aquatic toxicity at trace levels and have been often found in urban surface streams. In this study, samples were collected from the 182 ha Prado Wetlands in Southern California for seven months to assess the occurrence of fipronil and its degradation products as well as pyrethroids (bifenthrin and cyfluthrin) in water, sediment, and plants in a 4.45 ha vegetated surface flow constructed wetland (CW). Concentration-based removal values and changes in mass flux were calculated to determine the efficacy of CW treatment. Observed water concentrations were further used to calculate toxic units for the invertebrates Hyalella azteca and Chironomus dilutus. Pesticide concentrations in water, sediment, and plant samples consistently decreased during passage through the CW at all time points. Removal values for fipronil desulfinyl, fipronil sulfide, fipronil, fipronil sulfone, bifenthrin, and cyfluthrin were 100%, 99.7–100%, 57.8–88.1%, 75.6–100%, 74.7–100%, and 36.6–82.2%, respectively, and there was a general net deposition of pesticides into CW compartments. Toxic unit values decreased in every instance for both aquatic invertebrates. Settling of contaminated particles, adsorption to sediment, plant uptake or adsorption, and subsequent degradation contributed to the effective removal of these urban-use insecticides, which highlights the potential of CWs for protecting urban water quality.

Contaminação dos recursos hídricos por agrotóxicos na região central do Rio Grande do Sul, Brasil

O aumento na utilização de agrotóxicos na agricultura pode trazer graves consequências ao meio ambiente e à saúde da população, que consumir alimentos e água com resíduos de tais substâncias. Desta forma, o presente estudo buscou avaliar a presença e a concentração de agrotóxicos na água para consumo humano e, com isso, compreender os riscos à saúde que a população do município de Cachoeira do Sul está submetida. A metodologia consistiu na coleta e análise de amostras de água, em cinco épocas do ano, entre agosto de 2017 a março de 2018, sendo realizadas duas coletas de água tratada (na estação de tratamento e numa instituição de ensino) e uma de água do rio Jacuí, que abastece a cidade, sendo um total de 15 amostras. As amostras foram submetidas a análise por extração em fase sólida e cromatografia gasosa e líquida acoplada a espectrometria de massas. Os resultados mostraram a presença de resíduos de agrotóxicos em todas as amostras, com período crítico para contaminação entre fevereiro e março. No total, foram identificados 18 princípios ativos de agrotóxicos nas amostras de água, sendo o inseticida imidacloprido o de maior incidência e concentração, seguido pelos herbicidas clomazone e quincloraque. Os poluentes analisados persistiram mesmo após o tratamento da água, expondo a população aos riscos potenciais pela ingestão diária destes componentes. Medidas que promovam a remoção destes compostos na água, bem como alternativas ao modelo agrícola convencional precisam ser desenvolvidas e ampliadas, para promover a redução ou eliminação do uso dos agrotóxicos e proteção da saúde e meio ambiente.

National trends in pesticides in drinking water and water sources in Japan

Although agricultural activities—especially paddy rice cultivation—are prominent in watersheds in Asian countries, few comprehensive studies have examined pesticide concentrations in water in these areas. Here, we report the concentrations of 162 pesticides in treated drinking water and source water (14,076 samples) in Japan, where rice cultivation is common, along with trends in sales of herbicides, fungicides, and insecticides from 1963 to 2016. Herbicides and fungicides—especially those used in rice farming were frequently detected in drinking water sources.The herbicide bromobutide, which is not listed in drinking water quality standards or guidelines except in Japan, as well as the widely used-and-detected bentazone, were frequently detected in source water (bromobutide and bentazone were detected at concentrations >0.1 μg/L in 31.1% and 33.8% of samples, respectively). Dymron and tefuryltrione were also detected in over 10% of samples at concentrations >0.1 μg/L. The highest observed concentration of bromobutide was 10 μg/L, and 7.5% of samples had concentrations >1 μg/L. High concentrations were also observed for halosulfuron methyl (7.9 μg/L), pyroquilon (7.0), molinate (6.8), and metominostrobin (4.6). Some of the pesticides frequently detected in source water were not detected at all in drinking water, but the main cause of the non-detection appeared to be degradation by chlorine. From the 1970s onward, sales of herbicides and fungicides with higher acceptable daily intakes (ADIs; i.e., with lower toxicity) have increased. However, the percentage of herbicides with very low ADIs (<10–2.5 mg kg−1 d−1) being shipped has also increased. Tefuryltrione, which was detected at normalized concentrations >0.1 in 8% of samples, is an example of this type of herbicide. The average log-Kow of herbicides has decreased from the 1970s to the present, due to the strong trend towards the application of hydrophilic herbicides, such glyphosate. The need for increased monitoring of pesticides used in rice paddy farming is highlighted.

Pesticide accumulations in water and sediment of dam lakes located in Thrace part of Marmara Region (Turkey)

Ergene River Basin, which is located in the north-west part of Turkey, is the most significant aquatic habitat of Thrace Region. In addition to the presence of important lentic ecosystems in the basin, there are also important natural and artificial lotic ecosystems, which are of great importance both for the natural life and for the local public. Thrace Region is one of the most important and fertile agricultural regions of our country and despite such a great importance of Ergene River Basin for Thrace Region, almost all the components of the watershed are being exposed to an intensive pollution by means of especially agricultural applications. In this research, the pesticide concentrations in water – sediment of most significant 6 dam lakes (Altinyazi, Karaidemir, Kayalikoy, Kirklareli, Sultankoy and Suloglu Dam Lakes) located in Ergene River Basin were investigated. Water – sediment samples were taken in rainy season (spring) of 2018 from 15 stations and pesticide concentrations (174 pesticides varieties) were determined by using an LC/MS. In addition, the investigated locations were classified in terms of pesticide accumulations in water and sediment by using Cluster Analysis (CA). As a result of this research, 3 pesticide types in water and 18 pesticide types in sediment were detected. Carbendazim and forchlorfenuron-706 were recorded as the most dominant pesticide types for water samples and propiconazole and prochloraz were recorded as the most dominant pesticide types for sediment samples. The total pesticide contents determined in both water and sediment were found to be much higher in Altinyazi and Sultankoy Dam Lakes compared to the other investigated reservoirs. As a result of CA, 3 statistically significant clusters were formed both for water and sediment, which were named as “high contaminated zones”, low contaminated zones and moderate contaminated zones.

A sensitivity analysis of pesticide concentrations in California Central Valley vernal pools

Vernal pools are ephemeral wetlands that provide critical habitat to many listed species. Pesticide fate in vernal pools is poorly understood because of uncertainties in the amount of pesticide entering these ecosystems and their bioavailability throughout cycles of wet and dry periods. The Pesticide Water Calculator (PWC), a model used for the regulation of pesticides in the US, was used to predict surface water and sediment pore water pesticide concentrations in vernal pool habitats. The PWC model (version 1.59) was implemented with deterministic and probabilistic approaches and parameterized for three agricultural vernal pool watersheds located in the San Joaquin River basin in the Central Valley of California. Exposure concentrations for chlorpyrifos, diazinon and malathion were simulated. The deterministic approach used default values and professional judgment to calculate point values of estimated concentrations. In the probabilistic approach, Monte Carlo (MC) simulations were conducted across the full input parameter space with a sensitivity analysis that quantified the parameter contribution to model prediction uncertainty. Partial correlation coefficients were used as the primary sensitivity metric for analyzing model outputs. Conditioned daily sensitivity analysis indicates curve number (CN) and the universal soil loss equation (USLE) parameters as the most important environmental parameters. Therefore, exposure estimation can be improved efficiently by focusing parameterization efforts on these driving processes, and agricultural pesticide inputs in these critical habitats can be reduced by best management practices focused on runoff and sediment reductions.

Effects of season and sediment-water exchange processes on the partitioning of pesticides in the catchment environment: Implications for pesticides monitoring

Current and historic pesticide use has potential to compromise e.g. drinking water sources due to both primary and secondary emission sources. Understanding the spatial and temporal dynamics of emissions might help inform management decisions. To explore this potential; water, sediment and soil samples were concurrently collected from the River Ugie, Scotland over four seasons. Occurrence and fate of nine pesticides including four historic-use pesticides (HUPs): simazine, atrazine, isoproturon and permethrin, and five current-use pesticides (CUPs): metaldehyde, chlorpyrifos, chlortoluron, epoxiconazole and cypermethrin were analysed. Concentrations of target pesticides in water, sediments and soils were 4.5–45.6 ng·L−1, 0.9–4.6 ng·g−1 dw (dry weight) and 1.7–8.0 ng·g−1 dw, respectively. Concentrations of pesticides in water were found to significantly differ between seasons (p < 0.05). Significant differences in pesticide concentrations also occurred spatially within sediments (p < 0.01), indicating spatial and temporal associations with pesticide use. Sediment-water exchange showed that the sediment acts as an important secondary emission source particularly for the HUPs, while current local application and sediment emission are both major driving forces for CUPs in the riverine environment. These findings were supported by concentration ratios between different media, which showed potential as a preliminary assessment tool for identifying the source of pollutants in aquatic environments.

Pollution levels of banned and non-banned pesticides in surface sediments from the East China Sea

In this paper, 65 pesticides, including banned ones of DDTs, etc. and non-banned ones of iprobenfos, etc. have been detected in 31 surface sediment samples from the East China Sea (ECS) to study their pollution levels, sources, and risks. There were 8 banned pesticides (90–97%) and 10 non-banned pesticides (26–100%) presenting higher detection frequencies. For the 18 pesticides detected, their total contents ranged from 183.49 to 1363.77 ng/g dry weight (d.w.) and presented a seaward decreasing trend. Higher contents of banned pesticides were concentrated in the inner shelf close to Zhoushan Island. Iprobenfos, one of non-banned pesticides, showed the highest detection frequency (100%) and pollution level (79.14–1169.18 ng/g d.w.), indicating its continuous input in recent years. The pesticides concentrations in water calculated by the equilibrium partitioning (EqP) method were lower than the toxicological endpoint for tested aquatic invertebrates and fish, indicating ecological risks of these pesticides were at low levels.

Effects of water quality on aspects of reproductive biology of Cnesterodon decemmaculatus

The Suquía River basin (Córdoba, Argentina) is under a strong negative impact due to multiple sources of anthropic pollution. The main goal of our study was to evaluate if variations in the water quality of Suquía river basin affect the reproductive biology of Cnesterodon decemmaculatus and determine if the responses provided by the species can be considered as biomarkers of river quality. This assessment was performed through the measurement of morphological, histological and somatic parameters in adult males collected at four sampling sites during the beginning and the end of the breeding season. The water quality evaluation carried out through the estimation of a water quality index (WQI) and pesticides concentrations in water, revealed a pollution gradient along the studied basin. The same variation pattern was registered for the somatic index. In addition, the analysis of the morphology of the male copulatory organ (gonopodium) showed that individuals collected at Córdoba city had the lowest Gonopodium-Somatic Index (Gonop-SI) value, while those sampled at the most polluted site showed abnormalities in the small structures of the gonopodium. On the other hand, few histological alterations were found in the liver whereas no alterations were found in gonads along the river. The results obtained allowed us to characterize the environmental conditions of the studied basin and demonstrated the water quality deterioration along the Suquía River.

AGRO-2014: A time dependent model for assessing the fate and food-web bioaccumulation of organic pesticides in farm ponds: Model testing and performance analysis

A time-dependent environmental fate and food-web bioaccumulation model is developed to improve the evaluation of the behaviour of non-ionic hydrophobic organic pesticides in farm ponds. The performance of the model was tested by simulating the behaviour of 3 hydrophobic organic pesticides, i.e., metaflumizone (CAS Number: 139968-49-3), kresoxim-methyl (CAS Number: 144167-04-4) and pyraclostrobin (CAS Number: 175013-18-0), in microcosm studies and a Bluegill bioconcentration study for metaflumizone. In general, model-calculated concentrations of the pesticides were in reasonable agreement with the observed concentrations. Also, calculated bioaccumulation metrics were in good agreement with observed values. The model's application to simulate concentrations of organic pesticides in water, sediment and biota of farm ponds after episodic pesticide applications is illustrated. It is further shown that the time dependent model has substantially better accuracy in simulating the concentrations of pesticides in farm ponds resulting from episodic pesticide application than corresponding steady-state models. The time dependent model is particularly useful in describing the behaviour of highly hydrophobic pesticides that have a potential to biomagnify in aquatic food-webs.

Temporal-spatial patterns of three types of pesticide loadings in a middle-high latitude agricultural watershed

Pesticide loadings to watersheds increase during agricultural development and may vary in accordance with different crop types and seasons. High pesticide loadings can potentially result in polluted stream water. The objective of this study was to determine the pesticide loadings and concentrations of three typical pesticides (atrazine, oxadiazon, and isoprothiolane) in river water from a middle–high latitude agricultural watershed in northern China. During this study, we evaluated the watershed pesticide loss patterns for two crop types over three decades. For this purpose, we integrated data from field investigations, laboratory experiments, and modeling simulations involving a distributed hydrological solute transport model (Soil and Water Assessment Tool, SWAT). SWAT was employed to compare the temporal–spatial fate and behaviors of atrazine, oxadiazon, and isoprothiolane from 1990 to 2014 in a watershed area amounting to 141.5 km2. The results showed that the three pesticides could be detected at different locations throughout the watershed, and isoprothiolane was detected at the maximum value of 1.082 μg/L in surface runoff of paddy land. The temporal trend for the yearly loading of atrazine decreased slightly over time, but the trends for oxadiazon and isoprothiolane increased markedly over an 18-year analysis period. In regard to the pesticide concentrations in water, atrazine was associated with the largest value of nearly 1.4 μg/L. July and August were the found to be prime periods for pesticide loss from paddy land, and the biggest monthly loss of atrazine from dryland appeared in June. Under similar usage conditions, isoprothiolane loading from paddy fields ranked as the largest one among the three types of pesticides and reached up to 17 g/ha. Limited monitoring data were useful for validating the model, which yielded valuable temporal–spatial data on the fate of pesticides in this watershed. With the expansion of paddy rice cultivation, risks for pesticide contamination of water bodies will increase. The results of this study should be valuable for future exposure and risk assessments aimed at protecting the environment and human health.

Occurrence and fate of pesticides in the Argentine stretch of the Paraguay-Paraná basin.

The Argentine stretch of the del Plata basin crosses regions devoted to extensive and intensive agriculture mostly with chemical pest control. The utilization of pesticides in the region has increased 900% in the last two decades associated with the introduction of biotech crops and direct-seeding techniques. Our objective was to study the occurrence, concentration, and fate of pesticides in surface water and bottom sediments of the principal tributaries and main watercourse of the Paraguay-Paraná River. We sampled 22 sites in the distal positions of the main affluents and main watercourse of the Paraná and report here results from two monitoring campaigns (2010-2012). Surface water and bottom sediments were analyzed according to standardized methods by matrix-solid-phase dispersion and liquid-liquid extraction, respectively. Twenty-three pesticide compounds were analyzed by gas chromatography. The results from both campaigns indicated a generalized but variable distribution in the concentrations detected throughout the basin. The ranges of total measured pesticide concentrations in water and sediments were, respectively, 0.004-6.62μg/l and 0.16-221.3μg/kg dry weight. Endosulfans, cypermethrin, and chlorpyrifos were ubiquitous compounds in both environmental compartments and quantitatively the most relevant. All concentrations detected in water were over the recommended guidelines for the protection of aquatic biota. The partitioning indicated a higher affinity for the sediments. Agricultural activity is the source of pesticide-pollution loads, transported by tributaries that reach the main watercourse and alter the quality of the aquatic ecosystem.

Use of a versatile, easy, and rapid atmospheric monitor (VERAM) passive samplers for pesticide determination in continental waters.

The versatile, easy, and rapid atmospheric monitor (VERAM), a passive sampler device widely used for air monitoring, was evaluated as passive sampler for the determination of 23 pesticides in water. Gas chromatography with mass spectrometry detection was employed for determination of pesticides after microwave-assisted-extraction and specific clean-up of deployed samplers. The proposed methodology reached method detection levels from 2 to 10ng pesticide per sampler. Sampling rate (Rs) was determined for every pesticide from an uptake isotherm study performed at three different concentration levels (50, 125, and 250ngL-1). The obtained RS values ranged from 0.06 to 0.76L d-1. The obtained limits of detection for a 24-h passive sampling were from 4 to 50ngL-1. The effect of water parameters, such as temperature, pH, and ionic strength, were evaluated for their effect on pesticides retention using VERAMs. Pesticide RS values were independent of the water composition and increased on increasing temperature. Finally, the VERAM uptake was compared with that obtained using classic semipermeable membrane devices (SPMDs). This study is the first precedent for the use of VERAMs as passive samplers for the adsorption and concentration of pesticides in water and it confirms the satisfactory analytical figures of merit of VERAM as passive sampler of water. Graphical Abstract Scheme of water sampling of pesticides using versatile, easy, and rapid atmospheric monitor (VERAM) passive samplers.