Pestizide in Oberflächenwässern — Befunde in Talsperren und in Uferfiltraten Pesticides in Surface Water — Analytical Results for Drinking Water Reservoirs and Bank Filtrate Waters

The results of a series of investigations are presented, performed by the governmental chemical laboratory Karlsruhe (CLUA) in order to determine pesticides in drinking water for purposes of food monitoring. 231 samples of 8 municipal water supplies (groundwater wells/no bank filtrate) and 34 private water supplies close to the bank of the river Rhine (groundwater wells/partly bank filtrate) were analysed. The sampling sites were located between Mannheim and Greffern, Germany. In 1986 high amounts of atrazine and simazine were determined in the drinking water wells of several private water supplies, especially at the sampling sites in the south. The likewise high chloride content of the samples was taken as a proof of bank filtrate contributing to the water. The decrease of atrazine load in the river water of the Rhine since 1987 has its parallel in the analytical results for the concerned drinking water wells. Obviously the pesticide contamination of water from bank filtrate pumping wells is mainly depending on the pesticide load of the river water. The application of fertilizers and pesticides in the fields seems not to be a significant source of the pesticide contamination of dringing waters derived from bank filtrate water. For reasons of public health a monitoring of pesticide content in bank filtrate pumping wells of private water supplies is recommended.     

Evaluation of Two Low‐Cost–High‐Performance Adsorbent Materials in the Waste‐to‐Product Approach for the Removal of Pesticides from Drinking Water

This study evaluates the performance of two low cost and high performance adsorption materials, i.e., activated carbon produced from two natural waste products: Bamboo and coconut shell, in the removal of three pesticides from drinking water sources. Due to the fact that bamboo and coconut shell are abundant and inexpensive materials in many parts of the world, they respond to the “low‐cost” aspect. The adsorption capacities of two local adsorbents have been compared with commercial activated carbon to explore their potential to respond to the “high quality” aspect. Two pesticides were selected, namely dieldrin and chlorpyrifos, because they are commonly used in agriculture activities, and may remain in high concentrations in surface water used as drinking water sources. The results indicate that the adsorption of pesticides on activated carbons is influenced by physico‐chemical properties of the activated carbon and the pesticides such as the presence of an aromatic ring, and their molar mass. The activated carbon produced from bamboo can be employed as low‐cost and high performance adsorbent, alternative to commercial activated carbon for the removal of pesticides during drinking water production. The performance of activated carbon from bamboo was better due to its relatively large macroporosity and planar surface. The effect of adsorbent and pesticide characteristics on the performance was derived from batch experiments in which the adsorption behavior was studied on the basis of Freundlich isotherms.     

Efficacy of Selected Compounds on Thermocyclops oblongatus,one of the Main Intermediate Hosts of Guinea Worm in Africa

Ten selected compounds were tested on Thermocyclops oblongatus to determine their ability to be used for treatment of drinking water sources. None were shown to be interesting for individual application in household water tanks. Tested compounds, such as potassium permanganate or chlorine-releasing products, were ineffective or affected dramatically the taste or colour of the water. For collective application in water sources, temephos appeared to be the most valuable pesticide because it was effective against cyclops and harmless for environment. Other pesticides should be proposed as substitutes in case of cyclops resistance to temephos.     

Pesticides Removal Using Conventional and Low‐Cost Adsorbents: A Review

Worldwide pesticide usage has increased dramatically during the last three decades, coinciding with changing practices and increasing by intensive agriculture. This widespread use of pesticides for agricultural and non‐agricultural purposes has resulted in the presence of their residues in various environmental matrices. The occurrence of pesticides and their metabolite transported in rivers, channels, lakes, sea, air, soils, groundwater, and even drinking water, proves the high risk of these chemicals to human health and the environment. Therefore, pesticide removal is of an increasing concern. In this study, a review of the published literature dealing with pesticides removal process is presented. Firstly, pesticide removal by conventional means is briefly considered. Secondly, the use of the low‐cost sorbent through biosorption process is discussed comprehensively. The effect of factors such as pH, contact time, sorbent dosage, initial pesticide concentration, and optimization of biosorption conditions is also discussed. Kinetic, thermodynamic, and mechanism studies are also given. This study shows that both microorganisms and other materials with biological origin like agricultural by‐products may be used to this end. There is a significant potential for pesticide uptake by the use of various pristine and especially modified biosorbents. In the case of living organisms used as removal agents, degradation may also play a role in the total removal observed.     

Pesticide residues in ground water of the San Joaquin Valley, California

A regional assessment of non-point-source contamination of pesticide residues in ground water was made of the San Joaquin Valley, an intensively farmed and irrigated structural trough in central California. About 10% of the total pesticide use in the USA is in the San Joaquin Valley. Pesticides detected include atrazine, bromacil, 2.4-DP, diazinon, dibromochloropropane, 1,2-dibromoethane, dicamba, 1,2-dichloropropane, diuron, prometon, prometryn, propazine and simazine. All are soil applied except diazinon.

Pesticide leaching is dependent on use patterns, soil texture, total organic carbon in soil, pesticide half-life and depth to water table. Leaching is enhanced by flood-irrigation methods except where the pesticide is foliar applied such as diazinon. Soils in the western San Joaquin Valley are fine grained and are derived primarily from marine shales of the Coast Ranges. Although shallow ground water is present, the fewest number of pesticides were detected in this region. The fine-grained soil inhibits pesticide leaching because of either low vertical permeability or high surface area; both enhance adsorption on to solid phases. Soils of the valley floor tend to be fine grained and have low vertical permeability. Soils in the eastern part of the valley are coarse grained with low total organic carbon and are derived from Sierra Nevada granites. Most pesticide leaching is in these alluvial soils, particularly in areas where depth to ground water is less than 30m. The areas currently most susceptible to pesticide leaching are eastern Fresno and Tulare Counties.

Tritium in water molecules is an indicator of aquifer recharge with water of recent origin. Pesticide residues transported as dissolved species were not detected in non-tritiated water. Although pesticides were not detected in all samples containing high tritium, these samples are indicative of the presence of recharge water that interacted with agricultural soils.     

Gas Chromatography for Determination of Pesticides in Aquatic Systems — Analytical Basis Gaschromatographie zur Bestimmung von Pestiziden in aquatischen Systemen — Analytische Grundlagen

High resolution gas chromatography (HRGC) with ECD, NFID and MSD is a very efficient determination method for pesticides in water. Because of their relatively low concentrations in aquatic systems enrichment and preconcentration procedures are essential. Some examples for pesticide determination by GC methods are given. Potentials and limitations of HRGC for pesticide analysis are also discussed. An extensive pesticide analysis in water has to include different methods like HRGC, HPLC and GC/MS.     

Zielvorgaben für Pflanzenschutzmittelwirkstoffe und andere Schadstoffe in Oberflächengewässern

Quality Targets for Pesticides and Other Pollutants in Surface Waters Surface waters are not only adversely affected by industrial and municipal wastewaters but also by diffuse sources. For the control of the ecological water quality, so‐called quality targets are set. The quality targets are threshold concentrations for hazardous substances related to the protected goods like water ecosystems, drinking water supply, sediments, or fishing. In this paper, quality targets for the protection of aquatic life in surface waters were derived on the basis of a concept developed by the International Commission for the Protection of the Rhine (Internationale Kommission zum Schutze des Rheins – IKSR). The quality targets for the selected hazardous substances, which mainly belong to the chemical class of pesticides, were calculated using ecotoxicological results for species of bacteria, algae, fish, and small crustaceans, as the four trophic standards of the water ecosystem. In cooperation with the Federal Environmental Agency (Umweltbundesamt – UBA) the effect data were taken from ecotoxicological data bases. According to the concept of the IKSR, the lowest test result for the most sensitive species was multiplied by an assessment factor. This proceeding concerns the difficulty in describing the complex interactions in water ecosystems with toxicity data of single laboratory experiments for a few organisms. For seven pesticides quality targets below 0.1 μg/L were proposed. These results show that the ecotoxicologically based quality targets might be even lower than the limit values for pesticides in drinking water of 0.1 μg/L. But for most of the substances the determined values are significantly higher. The great concentration range of quality targets demonstrates distinctly that one standard concentration for all pesticides could not be given with regard to the different effects on aquatic organisms.     

Pesticide Health Risk Mapping and Sensitivity Analysis of Parameters in Groundwater Vulnerability Assessment

The extensive use of pesticides for increasing the agricultural production is affecting the quality of groundwater. The objectives of this article are to (i) develop pesticide relative leaching ranks for well sites, (ii) develop maps for human health risks due to pesticide applications, and (iii) identify the most significant parameters in pesticide simulations for groundwater vulnerability assessment. The methods include (i) development of acifluorfen relative leaching ranks for 25 well sites using ArcPRZM‐3, (ii) development of health risk maps using model simulated maximum dissolved bentazon concentrations on the basis of USA drinking water quality guidelines, (iii) sensitivity analysis for 14 ArcPRZM‐3 input parameters using the Plackett–Burman method. ArcPRZM‐3 is a user‐friendly system for spatial modeling of pesticide leaching from surface to groundwater. Thirteen acifluorfen relative leaching potential ranks were developed in which the pesticide leaching decrease from 1 to 13. The model predicted ranks for well 34 and well 9 were 2nd and 3rd, respectively, and acifluorfen was detected in both wells during the physical monitoring. The percentages of high health risks in the agricultural areas were 48.38 and 72.72% for Randolph and Independence Counties, respectively. The most significant parameters were thickness of horizon compartment, runoff curve number of antecedent moisture condition II for cropping, soil bulk density, and total application of pesticide. The irrigation, soil permeability, and numerical dispersion could impact the pesticide leaching in soils toward groundwater. The ArcPRZM‐3 system could be efficiently applied for spatial modeling and mapping of pesticide concentrations for groundwater vulnerability assessment on a large scale.     

Assessing Arkansas Ground Water for Pesticides: Methodology and Findings

During 1985 to 1987, 119 wells, Springs and municipal drinking water supplies throughout Arkansas were monitored for the presence of pesticides. Pesticides selected for analysis included acifluorfen, alachlor, aldicarb, atrazine, benomyl, cyanazine, cypermethrin, 2,4-D, dichlorprop, diuron, fenvalerate, fluometuron, hexazinone, linuron, metolachlor, permethrin, picloram, and propanil. Not every sample was analyzed for every pesticide. Overall, results indicated that the 18 herbicides, fungicides, and insecticides were not present in the ground water samples studied. (Note: Detectable concentrations of three herbicides – alachlor, atrazine, and metolachlor – were found in one irrigation well, at 5.5,5.8, and 6.9 μg/L, respectively. However, since previous and subsequent sampling failed to detect these compounds, their presence is attributed to a localized spill or handling error rather than agricultural application.)     

Environmental fate of fungicides and other current-use pesticides in a central California estuary

The current study documents the fate of current-use pesticides in an agriculturally-dominated central California coastal estuary by focusing on the occurrence in water, sediment and tissue of resident aquatic organisms. Three fungicides (azoxystrobin, boscalid, and pyraclostrobin), one herbicide (propyzamide) and two organophosphate insecticides (chlorpyrifos and diazinon) were detected frequently. Dissolved pesticide concentrations in the estuary corresponded to the timing of application while bed sediment pesticide concentrations correlated with the distance from potential sources. Fungicides and insecticides were detected frequently in fish and invertebrates collected near the mouth of the estuary and the contaminant profiles differed from the sediment and water collected. This is the first study to document the occurrence of many current-use pesticides, including fungicides, in tissue. Limited information is available on the uptake, accumulation and effects of current-use pesticides on non-target organisms. Additional data are needed to understand the impacts of pesticides, especially in small agriculturally-dominated estuaries.     

Modeling the Factors Impacting Pesticide Concentrations in Groundwater Wells

This study examines the effect of pumping, hydrogeology, and pesticide characteristics on pesticide concentrations in production wells using a reactive transport model in two conceptual hydrogeologic systems; a layered aquifer with and without a stream present. The pumping rate can significantly affect the pesticide breakthrough time and maximum concentration at the well. The effect of the pumping rate on the pesticide concentration depends on the hydrogeology of the aquifer; in a layered aquifer, a high pumping rate resulted in a considerably different breakthrough than a low pumping rate, while in an aquifer with a stream the effect of the pumping rate was insignificant. Pesticide application history and properties have also a great impact on the effect of the pumping rate on the concentration at the well. The findings of the study show that variable pumping rates can generate temporal variability in the concentration at the well, which helps understanding the results of groundwater monitoring programs. The results are used to provide guidance on the design of pumping and regulatory changes for the long‐term supply of safe groundwater. The fate of selected pesticides is examined, for example, if the application of bentazone in a region with a layered aquifer stops today, the concentration at the well can continue to increase for 20 years if a low pumping rate is applied. This study concludes that because of the rapid response of the pesticide concentration at the drinking water well due to changes in pumping, wellhead management is important for managing pesticide concentrations.     

Effect of Rigid PVC Bailer Contact on Detection of Pesticides in Water Samples

A field experiment was conducted to examine the effect of short-term (one minute) contact of pesticide-laden water with a polyvinyl chloride (PVC) bailer on quantitative laboratory measurements of seven pesticide concentrations in distilled water samples subsequently decanted from the bailer. Pesticides were tested at two initial concentrations (low. based on current FPA maximum contaminant levels, or MCL: and high, based on a multiple of approximately lour times the MCL). Pesticide species included bromoxynil, diclofop-m, dimethoate. MCPA, methyl parathion, propiconazole, and trifluralin. Dimethoate recoveries were poor for all treatments. For all other pesticides there was no systematic difference between pesticide concentrations measured before and after bailer contact. Effectiveness of bailer decontamination treatments consisting of distilled water rinse alone was related to water solubility (S) for each species. Distilled water samples decanted from a rigid PVC bailer following initial bailer contact with pesticide-spiked water, and after the bailer had been cleaned with a single distilled water rinse, had measured pesticide concentrations of less than 2 percent of the pesticide concentration in the initial pesticide-spiked water, regardless of S. A single distilled water rinse effectively removed all trace of contaminants having S> 500 mg/L. Multiple distilled water rinses, and multiple distilled water rinses followed by 15 bailings of a well, effectively removed all trace of contaminants having S> 50 mg/L. Below threshold S, cleaning effectiveness decreased as a power function of S.     

Pesticide residues analysis in lake water and sediment samples from the Golcuk National Park

Pesticide residues in surface water and sediments are extremely important because of their potential impacts on aquatic ecosystems and their implications on drinking water sources. Pesticide contamination of fresh water is causing concern with respect to long-term and low-dose effects of pesticides on public health, as well as their impact on no target species. Thus, intensive research on the fate and transport of pesticides in the environment is needed. Gas chromatography (GC) with electron-capture detection (ECD) and nitrogen-phosphorous detection (NPD) were employed for the identification of different pesticides in water and sediment samples. For this purpose, extraction procedure with dichloromethane and ethyl acetate were used. The aim of our work was the quantitative determination of pesticides from several compound classes in water and sediment from Gölcük National Park (Turkey). In GC-NPD/ECD, the detection limits were between 2.75–135 ng/L for the studied pesticides, recoveries ranged from 90 to 102% in samples and the relative standard deviations were in the range 1 to 10%. The correlation coefficients obtained from calibration curves of the pesticides standards were found to be 0.999. No pesticides residue was detected in the samples analyzed. This result is highly significant because of its impacts on public health and animals living in the Gölcük National Park.     

Decontaminating Materials Used in Ground Water Sampling Devices: Organic Contaminants

In these studies, the efficiency of various decontamination protocols was tested on small pieces of materials commonly used in ground water sampling devices. Three materials, which ranged in ability to sorb organic solutes, were tested: stainless steel (SS), rigid polyvinyl chloride (PVC), and polytetrafluoroethylene (PTFE). The test pieces were exposed to two aqueous test solutions: One contained three volatile organic compounds (VOCs) and one nitroaromatic compound, and the other contained four pesticides. Also, three types of polymeric tubing were exposed to pesticide solutions. Generally, the contact times were 10 minutes and 24 hours for sorption and desorption.
The contaminants were removed from the nonpermeable SS and the less-sorptive rigid PVC test pieces simply by washing with a hot detergent solution and rinsing with hot water. Additional treatment was required for the PTFE test pieces exposed to the VOCs and for the low-density polyethylene (LDPE) tubing exposed to the pesticide test solution. Solvent rinsing did not improve removal of the three VOCs from the PTFE and only marginally improved removal of the residual pesticides from the LDPE. However, a hot water and detergent wash and rinse followed by oven drying at approximately 105°C was effective for removing the VOCs from the PTFE and substantially reduced pesticide contamination from the LDPE.     

Pesticides in Nebraska's Ground Water

More than 2263 well water samples were collected throughout Nebraska and analyzed for pesticides. Thirteen and one-half percent contained detectable levels of atrazine, but only 22 wells exceeded the health advisory of 3.0 ppb. Although the samples came from almost every county in the state, this sampling is not based solely on a randomly selected group of wells. The highest frequency of detections occurred in irrigated corn-growing areas with less than 50 feet to ground water. These areas were sampled at a greater frequency than the less vulnerable areas. Cyanazine, together with the additional triazines — simazine, propazine, prometone, and ametryne, also were detected in some well waters; however, their frequency of detection was well below that of atrazine. The triazine metribuzin was not detected.
Alachlor, propachlor, and metolachlor also were detected in trace levels in several wells. Five of 2072 samples analyzed for alachlor exceeded the health advisory of 0.4 ppb. Almost all of the contaminated wells were in vulnerable areas. The relatively high frequency of propachlor detections occurred in predominately irrigated corn-growing areas, rather than in areas where propachlor is traditionally applied.
The factors that appear most directly involved in the observed distribution of pesticides in ground water are the intensity of areal usage, pesticide persistence and mobility, irrigation, soil drainage capacity, and depth to ground water.
Fifteen pesticide residues were detected during this study. If ethylene dibromide and carbon tetrachloride, which were detected in ground water adjacent to grain elevators are included, a total of 17 pesticide residues have been detected in Nebraska's ground water.     

Occurrence and Distribution of Organic Contaminants in the Aquatic System in Berlin. Part I: Drug Residues and other Polar Contaminants in Berlin Surface and Groundwater

Several polar contaminants were found in screening analyses of 30 representative surface water samples collected from rivers, lakes, and canals in Berlin. Residues of pharmaceuticals and N-(phenylsulfonyl)-sarcosine originating from various sewage treatment plants effluents were found at concentrations up to the μg/L-level in the surface water, whereas the concentrations of polar pesticides such as dichlorprop and mecoprop were always below 0.1 μg/L. The pharmaceuticals most frequently detected in the surface water samples include clofibric acid, diclofenac, ibuprofen, propiphenazone, and two other drug metabolites. Additional investigations of groundwater wells of a drinking water plant have shown that polar contaminants such as drug residues or N-(phenylsulfonyl)-sarcosine easily leach through the subsoil into the groundwater aquifers when contaminated surface water is used for groundwater recharge in drinking water production.     

Assessing herbicide concentrations in the saturated and unsaturated zone of a Chalk aquifer in southern England

The behavior of the herbicides isoproturon (IPU) and chlortoluron (CTU) in ground water and shallow unsaturated zone sediments were evaluated at a site situated on the Chalk in southern England. Concentrations of IPU in ground water samples varied from < 0.05 to 0.23 microgram/L over a five-year period of monitoring, and were found to correlate with application of the pesticide. Concentrations of pesticides in ground water samples collected during periods of rising water table were significantly higher than pumped samples and suggest that rapidly infiltrating recharge water contains higher herbicide concentrations than the native ground water. Significant variations in herbicide concentrations were observed over a three-month period in ground water samples collected by an automated system, with concentrations of IPU ranging from 0.1 to 0.5 microgram/L, and concentrations of a recent application of CTU ranging from 0.2 to 0.8 microgram/L. Different extraction methods were used to assess pore water concentrations of herbicides in the unsaturated zone, and samples were analyzed by standard HPLC analysis and immunoassay (ELISA) methods. These data indicated highly variable concentrations of herbicide ranging from 4 to 200 g/ha for HPLC and 0.01 to 0.04 g/ha for ELISA, but indicate a general pattern of decreasing concentrations with depth. The results of this study indicate that transport of IPU and CTU through the unsaturated zone to shallow ground water occurs and that this transport increases immediately following herbicide application. Measured concentrations of herbicides are generally lower than specified by the European Union Drinking Water Directive, but are observed to spike above this limit. These results imply that, while delivery of pesticides to ground water can occur as a result of normal agricultural practices, the impact on potable supplies is likely to be negligible due to the potential for degradation during the relatively long travel time through the unsaturated zone and high degree of dilution that occurs within the aquifer. As a result of the wide variation in concentrations detected by different techniques, it is suggested that for future site investigations more than one sampling strategy be employed to characterize the occurrence of pesticide residues and elucidate the transport mechanisms.     

Fate of Pesticides and Their Transformation Products: First Flush Effects in a Semi‐Arid Catchment

Although it is known for many years, that transformation products (TPs) of pesticides are often more persistent, mobile, and sometimes more toxic than the parent compound, former catchment scale studies of substance release and flushing effects focused only on the parent compound. In this study, four river points were sampled in the Hula Valley, Israel, and samples were analyzed in the lab for chlorpyrifos (CP) and endosulfan residues (including transformation products; TPs). Sampling results of the first rainfall in autumn 2009 identified a strong release of most substances to the rivers. First flush effects of these substances were assessed regarding the risk for drinking water supply and ecology, like fresh water invertebrates and fish. Although, these substances were found in Jordan River water during the first significant rainfall the observed levels are below international drinking water guideline values with no adverse effects on human health in the region. However, the observed CP and chlorpyrifos oxon (CPO) levels are above the acute toxicity for fresh water invertebrates and fish. The study shows that the Hula Valley was an important source of pesticides and TPs at the Upper Jordan River basin and that substance flushing is extremely important for pesticides‐monitoring campaigns.     

Responses of B-esterase enzymes in oysters (Crassostrea gigas) transplanted to pesticide contaminated bays form the Ebro Delta (NE,Spain)

Marine bivalves such as oysters are widely used as bioindicators to monitor marine coastal pollution. This study aimed to use B-esterase activity responses in oysters (Crassostrea gigas) cultured in Ebro Delta bays to monitor environmental effects of pesticides. The B esterases investigated were acetylcholinesterase, propionylcholinesterase, and carboxylesterase and their activities were measured in adductor muscle and gills from oysters transplanted in Ebro Delta bays where the are traditionally grown. Enzyme activities were related with physico-chemical parameters and pesticide levels measured in water. Cholinesterase activities measured in gills were unaffected across sites and periods. Conversely, carboxylesterase activities in oyster gills varied across periods and sites and were negatively correlated with residue levels of organophoshporous and carbamate pesticides in water. Therefore, inhibition of carboxylesterase activities can be considered a good indicator of exposure to anti-cholinergic pesticides in oysters.     

Leaching Potential of Turf Care Pesticides: A Case Study of Long Island Golf Courses

Pesticides used to maintain golf course turf can threaten ground water. This concern is particularly important in most of New York's Long Island, where generally sandy soils overlie a sole source aquifer. This study uses two methods to evaluate the potential for pesticides that are commonly used on Long Island's golf courses to leach to ground water.
Adapting the Pesticide Root Zone Model (PRZM). Release 1. for dense turf and applying site-specific soil data, certain pesticides, including metalaxyl and trichlorfon, are identified as potential problem leachers. PRZM simulations also identify the Long Island soils, including the sandy Plymouth and Carver soils, which arc most vulnerable to leaching.
When adequate input data for PRZM is unavailable, the ground water ubiquity score (GUS) method may be useful. GUS teachability classifications of pesticides commonly applied on Long Island golf courses, and of pesticides actually detected in ground water samples taken on Long Island, agree with PRZM predictions and the field data. The GUS method is applied to the evaluation of the leaching potential of pesticide degradation products (DCPA, maneb, and mancozeb metabolites), and the degradation products are shown to be a greater threat to ground water than their parent compounds.
These methods are potentially useful in designing ground water monitoring programs and for guiding the pesticide use and selection decisions of golf course managers.