Article

Pesticide authorization in the EU-environment unprotected?

Authors:
  • Landau Campus Universität Koblenz-Landau
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Abstract

Pesticides constitute an integral part of high-intensity European agriculture. Prior to their authorization, a highly elaborated environmental risk assessment is mandatory according to EU pesticide legislation, i.e., Regulation (EC) No. 1107/2009. However, no field data-based evaluation of the risk assessment outcome, i.e., the regulatory acceptable concentrations (RACs), and therefore of the overall protectiveness of EU pesticide regulations exists. We conducted here a comprehensive meta-analysis using peer-reviewed literature on agricultural insecticide concentrations in EU surface waters and evaluated associated risks using the RACs derived from official European pesticide registration documents. As a result, 44.7 % of the 1566 cases of measured insecticide concentrations (MICs) in EU surface waters exceeded their respective RACs. It follows that current EU pesticide regulations do not protect the aquatic environment and that insecticides threaten aquatic biodiversity. RAC exceedances were significantly higher for insecticides authorized using conservative tier-I RACs and for more recently developed insecticide classes, i.e., pyrethroids. In addition, we identified higher risks, e.g., for smaller surface waters that are specifically considered in the regulatory risk assessment schemes. We illustrate the shortcomings of the EU regulatory risk assessment using two case studies that contextualize the respective risk assessment outcomes to field exposure. Overall, our meta-analysis challenges the field relevance and protectiveness of the regulatory environmental risk assessment conducted for pesticide authorization in the EU and indicates that critical revisions of related pesticide regulations and effective mitigation measures are urgently needed to substantially reduce the environmental risks arising from agricultural insecticide use.

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... This runs contrary to global efforts to protect biodiversity and, in particular, also to the aims of the European Union's (EU) pesticide regulation [6]. Consistent exceedances of regulatory thresholds [7] and revisions of authorizations of pesticides, such as of neonicotinoid insecticides in the EU by the Standing Committee on plants, animals, food and feed (PAFF Committee), also attest to deficiencies in regulatory pesticide risk assessment and management. ...
... If the predicted exposure exceeds the safe concentration (as is the case for 2/3 of insecticides [7]), a pesticide can still be authorized if the producer can show through further data that its environmental and human health impacts are acceptable [8]. This is formalized as a tiered framework that extends the standard toxicity tests (first tier) to more complex scenarios (higher tiers) [11]. ...
... We suggest an increase in safety factors by a factor of at least 10 for all tiers (cf. [7,23,24]) to cover uncertainties arising from the ecological, landscape and management context and to align predicted and observed effects in ecosystems. Moreover, the authorization process should be comparative, i.e., compare the risks of a pesticide product to already authorized products, and include a cost-benefit analysis. ...
Article
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Agrochemicals, such as pesticides and fertilizers, have facilitated an unprecedented intensification of agriculture [1, 2]. However, the desired yield gains come at the cost of unwanted side effects on the environment. Pesticides have been demonstrated to contribute to the decline of non-target organisms, such as bees, birds and aquatic biodiversity [3–5], fueling the global biodiversity crisis. This runs contrary to global efforts to protect biodiversity and, in particular, also to the aims of the European Union’s (EU) pesticide regulation [6]. Consistent exceedances of regulatory thresholds [7] and revisions of authorizations of pesticides, such as of neonicotinoid insecticides in the EU by the Standing Committee on plants, animals, food and feed (PAFF Committee), also attest to deficiencies in regulatory pesticide risk assessment and management. We identify reasons why current authorisation procedures do not sufficiently protect biodiversity and suggest how these drawback could be overcome.
... pesticides frequently exceed regulatory acceptable concentrations (RACs) (Stehle and Schulz, 2015b;Szöcs et al., 2017) and even pose a greater threat to European surface water ecology than any other pollutant class (Malaj et al., 2014;Wolfram et al., 2021). Pesticides have been shown to impair surface water fauna and flora within Europe (Beketov et al., 2013;Larras et al., 2017;Liess et al., 2021a;Liess and Ohe, 2005;Schäfer et al., 2011), but also worldwide, for example in Africa (Ganatra et al., 2021), Australia (Burgert et al., 2011;Wood et al., 2019) and North and South America (Chiu et al., 2016;Hunt et al., 2017). ...
... Small stream ecosystems are considered biodiversity hotspots, offering diversified habitats for numerous animal, plant, algae and fungi species, and act as recolonization sources for impaired downstream reaches (Liess and Ohe, 2005;Orlinskiy et al., 2015). Such streams have also been shown to be particularly susceptible to agricultural diffuse pesticide pollution, often being located in direct proximity to agricultural fields while lacking the capacity of larger waters to dilute pesticide inputs (Schulz, 2004;Stehle and Schulz, 2015b;Szöcs et al., 2017). These inputs are mostly due to rainfallinduced surface runoff transporting pesticide residues from fields into adjacent streams, resulting in short-term concentration peaks (Liess et al., 1999). ...
... Wolfram et al. (2021) estimated a median catchment area of 238 km 2 of European surface waters monitored under the WFD, while the median catchment area of the natural river network is less than 20 km 2 . Small streams are thus underrepresented in the WFD monitoring site selection while being particularly susceptible to pesticide pollution (Lorenz et al., 2017;Schulz, 2004;Stehle and Schulz, 2015b;Szöcs et al., 2017). This especially concerns small waters with catchments of <10 km 2 , which are completely omitted from regular WFD monitoring and are not required to achieve good status despite making up approximately two thirds of the entire river network (BfN, 2021). ...
Article
Full-text available
The Water Framework Directive (WFD) demands that good status is to be achieved for all European water bodies. While governmental monitoring under the WFD mostly concludes a good status with regard to pesticide pollution, numerous scientific studies have demonstrated widespread negative ecological impacts of pesticide exposure in surface waters. To identify reasons for this discrepancy, we analysed pesticide concentrations measured in a monitoring campaign of 91 agricultural streams in 2018 and 2019 using methodologies that exceed the requirements of the WFD. This included a sampling strategy that takes into account the periodic occurrence of pesticides and a different analyte spectrum designed to reflect current pesticide use. We found that regulatory acceptable concentrations (RACs) were exceeded for 39 different pesticides at 81% of monitoring sites. In comparison, WFD-compliant monitoring of the same sites would have detected only eleven pesticides as exceeding the WFD-based environmental quality standards (EQS) at 35% of monitoring sites. We suggest three reasons for this underestimation of pesticide risk under the WFD-compliant monitoring: (1) The sampling approach - the timing and site selection are unable to adequately capture the periodic occurrence of pesticides and investigate surface waters particularly susceptible to pesticide risks; (2) the measuring method - a too narrow analyte spectrum (6% of pesticides currently approved in Germany) and insufficient analytical capacities result in risk drivers being overlooked; (3) the assessment method for measured concentrations - the protectivity and availability of regulatory thresholds are not sufficient to ensure a good ecological status. We therefore propose practical and legal refinements to improve the WFD's monitoring and assessment strategy in order to gain a more realistic picture of pesticide surface water pollution. This will enable more rapid identification of risk drivers and suitable risk management measures to ultimately improve the status of European surface waters.
... Exposure to pesticides can have detrimental effects on aquatic communities of non-target species, even at legally accepted concentrations (Stehle and Schulz, 2015). Populations can, however, evolve tolerance to pesticides which may rescue them from extinction. ...
... This matches other experimental evolution trials showing an increased pesticide tolerance to chlorpyrifos (Ejaz et al., 2017) and other pesticides, for example carbaryl (Jansen et al., 2011b). These example studies used a longer exposure duration (Ejaz et al., 2017: nine generations;Jansen et al., 2011b: 54 days) and/or higher exposure concentration (Jansen et al., 2011b: 4 times the EC 50 48 h ) in comparison to the current study where the daphnids were only exposed for two pulses spread over two weeks to the EC 50 48 h of the adults (0.35 µg/L), which is a realistic exposure scenario in water bodies close to agricultural land (Stehle and Schulz, 2015). Current design therefore illustrates that under such realistic conditions, rapid evolution of pesticide tolerance may occur. ...
Article
Exposure to pesticides can have detrimental effects on aquatic communities of non-target species. Populations can evolve tolerance to pesticides which may rescue them from extinction. However, the evolution of tolerance does not always occur and insights in the underlying mechanisms are scarce. One understudied mechanism to obtain pesticide tolerance in hosts are shifts toward pesticide-degrading bacteria in their microbiome. We carried out experimental evolution trials where replicated experimental populations of the water flea Daphnia magna were exposed to the pesticide chlorpyrifos or a solvent control, after which we performed acute toxicity assays to evaluate the evolution of chlorpyrifos tolerance. Additionally, we quantified changes in the microbiota community composition of whole body and gut samples to assess which sample type best reflected the pesticide tolerance of the Daphnia host. As expected, chlorpyrifos-selected clones became more tolerant to chlorpyrifos as shown by the higher EC50 48 h (36% higher) compared with the control clones. This was associated with shifts in the microbiome composition whereby the abundance of known organophosphate-degrading bacterial genera increased on average ~4 times in the chlorpyrifos-selected clones. Moreover, the abundances of several genera, including the organophosphate-degrading bacteria Pseudomonas, Flavobacterium and Bacillus, were positively correlated with the EC50 48 h of the host populations. These shifts in bacterial genera were similar in magnitude in whole body and gut samples, yet the total abundance of organophosphate-degrading bacteria was ~6 times higher in the whole body samples, suggesting that the gut is not the only body part where pesticide degradation by the microbiome occurs. Our results indicate that the microbiome is an important mediator of the development of tolerance to pesticides in Daphnia.
... To account for uncertainties related to the projection of toxicity assessments from benign laboratory conditions towards harsher field conditions and to predict regulatory acceptable concentrations (RACs), an assessment factor of 100 below the acute LC50 (the concentration lethal to 50% of the test organisms) has been established (see e.g., [30]). However, measured insecticide concentrations in surface waters often exceed their respective RACs, as observed, for example, in a meta-analysis of peer-reviewed literature on agricultural insecticide concentrations in EU surface waters [31]. Furthermore, detrimental impacts of pesticides on structure and/or biodiversity of agricultural streams have been observed frequently [32][33][34]. ...
... Furthermore, detrimental impacts of pesticides on structure and/or biodiversity of agricultural streams have been observed frequently [32][33][34]. Indeed, an increasing number of recent studies have concluded that current pesticide regulations do not sufficiently protect the aquatic environment and that insecticides threaten aquatic biodiversity [5,6,31,35,36]. ...
Article
Full-text available
Interactions of pesticides with biotic or anthropogenic stressors affecting stream invertebrates are still poorly understood. In a three-factor laboratory experiment, we investigated effects of the neonicotinoid imidacloprid, food availability, and population density on the New Zealand mayfly Deleatidium spp. (Leptophlebiidae). Larval mayflies (10 or 20 individuals) were exposed to environmentally realistic concentrations of imidacloprid (controls, 0.97 and 2.67 μg L−1) for nine days following five days during which individuals were either starved or fed with stream algae. Imidacloprid exposure had severe lethal and sublethal effects on Deleatidium, with effects of the lower concentration occurring later in the experiment. The starvation period had delayed interactive effects, with prior starvation amplifying imidacloprid-induced increases in mayfly impairment (inability to swim or right themselves) and immobility (no signs of movement besides twitching appendages). Few studies have investigated interactions with other stressors that may worsen neonicotinoid impacts on non-target freshwater organisms, and experiments manipulating food availability or density-dependent processes are especially rare. Therefore, we encourage longer-term multiple-stressor experiments that build on our study, including mesocosm experiments involving realistic stream food webs.
... Solomon et al., 2008). In brief, ERA starts at Tier 1 and can highlighting the need to adapt the ecotoxicological assessment of PPP within the regulation procedure to improve the protection of biodiversity (Schäfer et al., 2019;Stehle & Schulz, 2015). Previous statements already asked for (i) adopting more holistic and realistic approaches in PPP risk assessment (Möhring et al., 2020;Schäfer et al., 2019), (ii) considering the landscape scale (Streissl et al., 2018) and (iii) integrating mixture effects (Stehle & Schulz, 2015) in order to better predict the effects of PPP on the environment. ...
... In brief, ERA starts at Tier 1 and can highlighting the need to adapt the ecotoxicological assessment of PPP within the regulation procedure to improve the protection of biodiversity (Schäfer et al., 2019;Stehle & Schulz, 2015). Previous statements already asked for (i) adopting more holistic and realistic approaches in PPP risk assessment (Möhring et al., 2020;Schäfer et al., 2019), (ii) considering the landscape scale (Streissl et al., 2018) and (iii) integrating mixture effects (Stehle & Schulz, 2015) in order to better predict the effects of PPP on the environment. According to EFSA (European Food Safety Authority), modelling approaches can help to refine risk assessment as it may improve, for example, the ecological realism and reduce the uncertainties (e.g., using higher number of species, considering trophic interactions or exposure changes according to life-cycle or landscape) (EFSA, 2009;EFSA PPR Panel, 2013, 2014. ...
Article
Before their placing on the market, the safety of plant protection products (PPP) towards both human and animal health, and the environment has to be assessed using experimental and modelling approaches. Models are crucial tools for PPP risk assessment and some even help to avoid animal testing. This review investigated the use of modelling approaches in the ecotoxicology section of PPP active substance assessment reports prepared by the authorities and opened to consultation from 2011 to 2021 in the European Union. Seven categories of models (Structure-Activity, ToxicoKinetic, ToxicoKinetic-ToxicoDynamic, Species Sensitivity Distribution, population, community and mixture) were searched for into the reports of 317 active substances. At least one model category was found for 44 % of the investigated active substances. The most detected models were Species Sensitivity Distribution, Structure-Activity and ToxicoKinetic for 27, 21 and 15 % of the active substances, respectively. The use of modelling was of particular importance for conventional active substances such as sulfonylurea or carbamates contrary to microorganisms and plant derived substances. This review also highlighted a strong imbalance in model usage among the biological groups considered in the European Regulation (EC) No 1107/2009. For example, models were more often used for aquatic than for terrestrial organisms (e.g., birds, mammals). Finally, a gap between the set of models used in reports and those existing in the literature was observed highlighting the need for the implementation of more sophisticated models into PPP regulation.
... Increasing water insecticide contamination and associated decreasing regional aquatic biodiversity are evident worldwide (Stehle and Schulz, 2015a). Newer-generation insecticides (e.g., pyrethroids) had higher exceedances of regulatory thresholds than legacy ones (e.g., organochlorine pesticides) (Stehle and Schulz, 2015a;Stehle and Schulz, 2015b). Thus, it is of great importance to assess and control potential risk caused by newer-generation insecticides in aquatic systems. ...
... Thus, it is of great importance to assess and control potential risk caused by newer-generation insecticides in aquatic systems. As hydrophobic insecticides tend to be bound to suspended particles and accumulated in sediment (Katagi, 2006), they pose great risk to benthic organisms (Stehle and Schulz, 2015b). ...
Article
Influence of sediment particle size on the desorption, bioavailability, and bioaccumulation potential of cypermethrin was investigated in the present study using two biomimetic techniques (Tenax extraction and solid-phase microextraction (SPME)) and bioaccumulation testing with Lumbriculus variegatus. A field-collected sediment was wet sieved to obtain five particle-size fractions (<20, 20-63, 63-180, 180-500, and >500 μm) and used for cypermethrin spiking. The finest sediment (<20 μm) had the highest rapid desorption fraction (Fr) and rate (kr) when compared to coarser sediments. Elimination rate constants of cypermethrin determined by SPME (ke-SPME) and L. variegatus (ke-L.v.) for various fractions of sediments followed the same trend, suggesting SPME fiber acts as a good surrogate for benthic organisms considering passive partitioning. Finally, biota-sediment accumulation factors (BSAFs) of cypermethrin in worms were almost the same among the sediments with different particle sizes (0.425 ± 0.07-0.445 ± 0.07 g OC g-1 lipid), suggesting that the differences in desorption and freely dissolved concentrations of cypermethrin did not significantly influence its bioaccumulation potential in worms. Selective ingestion of fine sediment particles may be one of the contributing reasons for no differences in BSAFs observed in the treatments as would have been expected. The different desorption and freely dissolved concentrations of cypermethrin in sediments with different particle sizes observed in this study highlights the need for further work to better understand the influence of particle size on the toxicity of highly toxic insecticides, such as cypermethrin, to sensitive benthic species.
... The existing regulatory acceptable concentrations (RACs) of pesticides were not considered to be the ecotoxicological objectives of the indices because according to Stehle and Schulz (2015a) a critical reconsideration of the ecotoxicity endpoints (RACs) of highly toxic compounds is suggested and besides there is a lack of protectiveness in the higher-tier RACs of insecticidal compounds. ...
Article
During the last decade numerous monitoring programs have been conducted in order to assess pesticide pollution in catchments. This effort has led to the production of large, complex data sets of environmental results making the task of evaluation of the aquatic chemical status more difficult. Furthermore, the evaluation of the chemical status of the water ecosystems is one of the main aspects which should be considered in a River Basin Management Plan. In this study, two indices were developed in order to assess the combined pesticide ecotoxicity to aquatic non-target organisms, the Aquatic Quality Index of Short term Toxicity of Pesticides (AQI ShToxP) and the Aquatic Quality Index of Long term Toxicity of Pesticides (AQI LToxP). These indices were applied to the environmental results obtained from an intensive monitoring study of 302 pesticides in 102 stationary sampling stations located on the surface aquatic network of the Pinios River Basin, in Greece, in 2011 and 2012. The evaluation of the surface water quality was achieved by taking into consideration the frequency and the intensity of exposure of the aquatic organisms to pesticides above the respective ecotoxicological quality objectives such as the acute or chronic term predicted no-effect concentrations derived from risk assessment. Seventy-five pesticides, that have been previously identified as the River Basin Specific Pollutants of Pinios by an environmental and human risk hierarchy exercise, were assessed. It appears, from the implementation of the two indices, that the detected pesticides in the surface aquatic ecosystem of the Pinios River Basin exert significant pressure on the aquatic non-target organisms especially at the chronic effect level. The developed AQI ShToxP and AQI LToxP indices, as well as the proposed quality classification system could be valuable communication and interpretation tools for River Basin Management Plans that can contribute in the restoration of environmental health.
... In European surface waters, higher median concentrations were observed for fungicides (0.96 μg/L; n = 87; 23 compounds) compared to those of herbicides (0.063 μg/L; n = 852; 36 compounds) and insecticides (0.034 μg/L; n = 1408; 59 compounds). 53 This might be related to the persistence of many fungicides in the environment, application rates/scenarios, and/or spatial patterns of their agricultural use in the landscape. Accordingly, individual fungicides have been reported at concentrations exceeding 1 μg/L in streams during base flow, and sum concentrations of several dozen μg/L were detected during runoff. ...
Article
Fungicides are indispensable to global food security and their use is forecasted to intensify. Fungicides can reach aquatic ecosystems and occur in surface water bodies in agricultural catchments throughout the whole growing season due to their frequent, prophylactic application. However, in comparison to herbicides and insecticides, the exposure to and effects of fungicides have received less attention. We provide an overview of the risk of fungicides to aquatic ecosystems covering fungicide exposure (i.e., environmental fate, exposure modelling, and mitigation measures) as well as direct and indirect effects of fungicides on microorganisms, macrophytes, invertebrates, and vertebrates. We show that fungicides occur widely in aquatic systems, that the accuracy of predicted environmental concentrations is debatable, and that fungicide exposure can be effectively mitigated. We additionally demonstrate that fungicides can be highly toxic to a broad range of organisms and can pose a risk to aquatic biota. Finally, we outline central research gaps that currently challenge our ability to predict fungicide exposure and effects, promising research avenues, and shortcomings of the current environmental risk assessment for fungicides.
... Small streams, which harbour a major proportion of total freshwater biodiversity (Le et al., 2017;Schulz, 2004), tend to receive higher inputs of pesticides because they are more interconnected with the surrounding landscape; on top of that, their dilution potential is lower than for larger water bodies, so proportionally higher pesticide contamination can be expected in smaller rivers (Le et al., 2017;Schulz, 2004;Stehle and Schulz, 2015;Szöcs et al., 2017). However, b10% of pesticide monitoring studies published to date in scientific literature have been conducted in small streams (Lorenz et al., 2017;Szöcs et al., 2017). ...
... Despite the availability of large datasets for pesticides and well developed risk assessment methods, evidence is mounting on environmental impacts which were not predicted by current methods e.g., impacts on pollinators (Goulson et al. 2015, Woodcock et al. 2015, birds Hallmann et al. 2014 andaquatic organisms (Sánchez-Bayo et al. 2016). There is also evidence that concentrations of pesticides in surface water can exceed regulatory acceptable concentrations (Stehle and Schulz 2015). Some authors plea for pesticide vigilance and monitoring programs similar to pharmaceuticals (Milner and Boyd 2017). ...
Article
Full-text available
Each year, the European Food Safety Authority, supported by a network of experts in the EU Member States, assesses and publishes the environmental risks of 30-40 pesticides active substances. The assessments support hundreds of national risk evaluations for marketing (re-)authorisations of Plant Protection Products. These prospective regulatory evaluations are based on worst-case scenarios in order to provide the high level of protection required by the EU legislations, and establishes the conditions for a correct use of the products including risk mitigations options. However, recent publications suggest that the desired high level of protection may not be achieved with the current risk assessment paradigm. The consideration of larger spatial scales and multiple stressors, including different pesticide uses, could improve the risk assessment process. A next step is the use of these larger spatial scales for evidence-based assessments, evaluating the overall impact of pesticide use on the European environment and biodiversity. Reaching this level would provide science-based support to the National Plans on sustainable use of pesticides and to the broader EU policies defined in the EU Environmental Action Programmes. Recent technological developments, as well as policy efforts, have solved two of the key issues blocking this progress in the past. Data availability and technical capacity for handling Big Data are no longer an unaffordable obstacle. The current proposal presents an alternative environmental risk assessment paradigm, integrating use patterns and pesticides properties with landscape ecotypes and eco-regions, covering the variability of the European agro-environmental conditions. The paradigm is suggested to be implemented in a spatially explicit conceptual model, using the ecosystem services approach and vulnerable key driver species to represent the service providing units. This approach would allow mapping the likelihood and magnitude of the impact of pesticide use on ecosystems functions, environmental resources, and biodiversity at the EU scale.
... In a study conducted by Van den Berg et al. (2020) on gaps in the pesticide lifecycle management in agriculture and public health in both developed and developing countries, it was shown that global shortcomings exist but are more aggravated in the developing countries (Van den Berg et al., 2020). It is also a fact that no country in the world, even the wealthiest one, will ever have the ultimate lifecycle management performing at 100% certainty (Centner, 2018;Stehle and Schulz, 2015;Storck et al., 2017). If we are talking about risk (Skevas et al., 2013), all that can be done is to build a policy based on reducing the uncertainty or mitigating risk to an acceptable level. ...
Article
Full-text available
Countrywide pesticide management activities are resource draining, even for developed countries, which sometimes fall short in achieving the optimum protection against pesticides deleterious effects on humans and environment. Additionally, in Lebanon, basic flaws exist at different levels of pesticide management cycle. In this study, through an extensive review of relevant literature regarding the pesticides impact on humans and environment in Lebanon and adopted policies in existing legislation, several gaps have been identified. Accordingly, recommendations to reduce pesticide risk through a combination of reforms at the policy level and its tools, particularly legislation, are proposed. In our opinion, the starting point is to adopt a minimum list of lower risk pesticides supported by a combination of: "prescriptions" based on a comprehensive registration and an effective implementation systems, a suitable IPM/ICM government-supported credit system, traceability systems of agricultural commodities and pesticides containers, Pesticide stock management system to reduce the quantity of obsolete pesticides, and containers recycling system. For a global sustainability of pesticides risk reduction, a binding global intervention fostered by the UN, based on human rights for safe food, is called upon to ban hazardous pesticides-except those of WHO class IV-trafficking in developing countries scoring low in an international official assessment of their pesticides lifecycle management. At the same time, global funds should support pesticides alternatives and the enhancement of the developing countries capacities for pesticides lifecycle management, which is a part of a larger global matrix in risk reduction.
... SPs have higher aquatic risk associated with their use compared with older-generation insecticides (Stehle and Schulz 2015a;Stehle and Schulz 2015b); thus, SP contamination in urban aquatic environments has drawn worldwide attention. ...
Article
Full-text available
Temporal–spatial distribution of synthetic pyrethroids (SPs) in overlying water and surface sediments and ecological risk to aquatic systems were investigated, where paired water and surface sediments were collected during dry and wet periods in Guangzhou urban waterways. Eight target SPs (i.e., tefluthrin, bifenthrin, cyhalothrin, permethrin, cyfluthrin, cypermethrin, esfenvalerate, and deltamethrin), with cypermethrin and permethrin as major components, were ubiquitously detected in both water (dissolved and particle phases, separately) and sediments. Significant increases of ΣSP (sum of eight SPs) concentrations were observed in both water and sediment from the dry period to the wet period. The spatial distribution of SPs was mostly impacted by land-use type, with the highest ΣSP concentrations in the residential areas, which indicates the massive application of pyrethroids in household mosquito control. It is demonstrated that SPs preferred to be adsorbed to the particles, and rainfall-induced runoff was suggested as an important mechanism that moved SPs to the receiving waterways. A rising trend on sediment concentrations of SPs in the Guangzhou area in the last decade implied increasing application of pyrethroid insecticides, with cypermethrin and permethrin as the dominant components, where the contamination of SPs was positively related with urbanization rate (e.g., resident population and green coverage area). A special emphasis was placed on the potential effects of both individual SPs and their mixtures in three trophic levels (i.e., algae, daphnia, and fish) using toxic units (TUs) and risk quotients (RQs) for water and sediments. In spite of no acute effects due to SPs in the sediments, the toxic units showed daphnia as the most sensitive species in water, with acute risks to daphnia exhibited in several sampling sites. The risk assessment points out that a chronic toxicity (RQ index) caused by SPs in three trophic levels (algae, daphnia, and fish) exists, especially in Daphnia magna.
... 7,8 Insecticides exhibit aquatic toxicities 9−11 approximately 2 orders of magnitude higher than other types of pesticides (e.g., herbicides and fungicides). 12 Like all pesticides, they have to be registered by the US Environmental Protection Agency (EPA) prior to their use in the United States. 13 During the mandatory ecological risk assessment accompanying insecticide registration, regulatory threshold levels (RTLs, see Stehle and Schulz 10 ) are derived from the most sensitive end point of a variety of tested species, that is, algae, invertebrate, and fish, by multiplying the measured toxicity with a so-called "level of concern" (0.05−1). ...
Article
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Although pesticide contamination in agricultural surface waters is a common phenomenon, large-scale studies dealing with the responsible drivers are rare. We used data from 259 publications reporting 5,830 individual water or sediment concentrations of 32 insecticides and their metabolites in 644 U.S. surface waters to determine the factors driving insecticide risks, i.e. exceedance of regulatory threshold levels (RTLs). Multiple linear regressions (R² adj. = 49.6 – 76.5) revealed that toxicity-normalized agricultural insecticide use (i.e. use divided by toxicity) was the most important driver. Burst rainfall erosivity and irrigation practices also had risk-promoting effects, whereas time, catchment size, and sampling interval had risk-demoting effects. A regression model (R² adj. = 62.2, n = 1,833) for small, medium, and large running waters was validated and used for risk mapping at the national scale, highlighting multiple regions where the comparison of predicted insecticide concentrations with their RTLs indicate adverse conditions for aquatic organisms. Particularly in smaller streams, risks were most pronounced with an average RTL exceedance frequency of 27.7%. Finally, mixture toxicity, was mainly (about 76.7%) explained by the most toxic compound in the mixture, causing ~95.7% of RTL exceedances. Identifying the factors driving exposure for all relevant insecticide classes and mapping resulting risks in surface waters of various sizes across the U.S. supports future risk management.
... In contrast, herbicides, fungicides and degradates all showed ALB exceedances below 3% indicating negligible aquatic risks of these compounds. Higher threshold level exceedance rates for insecticides compared with other pesticide types have also been reported for urban surface waters in the U.S. (Stone et al., 2014;Carpenter et al., 2016;Nowell et al., 2018), 4000 freshwater monitoring sites across the EU (Malaj et al., 2014), as well as in agricultural surface waters in EU (Stehle and Schulz, 2015b). Despite the fact that herbicide usage is twice as high than insecticide usage by mass in urban settings of the U.S. (Atwood and Paisley-Jones, 2017), the high ecotoxicities particularly towards invertebrates substantiates insecticides' higher risk potentials (Devine and Furlong, 2007;Stehle and Schulz, 2015). ...
Article
Full-text available
Non-agricultural uses of pesticides are common in the U.S. and may thus lead to exposure of non-target ecosystems such as urban waterways. However, surface water exposure resulting from agricultural pesticide uses has received substantially more attention during the last decades. Here we conducted a literature review and meta-analysis of peer-reviewed studies to identify measured environmental concentrations (MEC) of pesticides in perennial surface water bodies due to non-agricultural uses in the U.S. Acute and chronic Aquatic Life Benchmarks (ALB acute , ALB chronic) for water-phase concentrations and regulatory threshold levels (RTL SED) for sediment concentrations were used for risk evaluations. Based on 10,755 MECs retrieved from 70 scientific studies, results show that a multitude of pesticide compounds (approx. 150) have been detected at 609 urban surface water sites. Particularly herbicides and insecticides were among the most frequently detected compounds in the water phase, whereas insecticides dominated detections in sediments. While overall acute (5.64% ALB acute exceedances; n = 9034 MEC) and chronic (9.31% ALB chronic exceedances; n = 9036 MEC) risks were comparably low in the water phase, 35% of sediment concentrations (n = 1621 MEC) exceeded RTL SED. Insecticides and particularly pyrethroids were identified as the main drivers of benchmark exceedances in both the water phase and sediments. In addition to pesticide type, a linear model analysis identified further drivers important for risks such as sampling methods. Overall insecticide risks in non-agricultural surface waters were significantly (by a factor of 1.9) lower than those already known from agricultural surface waters in the U.S. However, substantially higher risks in sediments were identified for urban compared with agricultural waterbodies. The present study provides the first comprehensive assessment of pesticides in urban surface waters in the U.S. with overall results indicating common occurrence and non-negligible risks particularly due to urban insecticide uses.
... A few scientific assessments of the European ERA scheme and its shortcomings exist (e.g. Newman et al., 2006;Schäfer et al., 2011;Stehle and Schulz, 2015b;Storck et al., 2017). Main points that are often raised are the inclusion of new test or surrogate species, the extension of studies to more realistic scenarios, the validity of the used uncertainty (assessment) factors, the lack of including sublethal endpoints in risk assessments and the need to address ignored groups of organisms (e.g. ...
Article
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Risk Management Instead of Assessment The development of a new systemic approach for ERA will take considerable time and require substantial resources. We therefore also need to discuss other options to at least halt the negative effects of pesticides on biodiversity of the agricultural landscape. Risk management to mitigate negative pesticide effects might be a helpful alternative until we are able to assess the true environmental risk of pesticide usage. Reducing pesticides in agricultural practice is an obvious option. It was estimated that total pesticide use could be reduced by more than 40% in almost 60% of 946 evaluated farms in a French network without any negative effects on both productivity and profitability (Lechenet et al., 2017). Integrated pest management should focus on using natural enemies of pests and crop rotations and agree on pesticides as a last option instead of current practices, where pesticides are prophylactically implemented in farming practices (e.g., seed-treatments of cereals). We additionally could extend the proportion of semi-natural habitats without pesticide inputs in the agricultural landscape, increase agri-environmental schemes and enlarge the area of organic farming. Many options are on the table and a strengthening of the greening of the common agricultural policy (CAP) is currently discussed for the coming period of European policy (Erjavec and Erjavec, 2015; Solazzo et al., 2016; Alons, 2017). Risk mitigation of pesticides needs to be implemented effectively and at a large scale to bend the curve of biodiversity decline in agricultural landscapes now. If we delay to change agricultural practice and its current pesticide use our efforts to stop the current biodiversity decline and restore it to former levels need to be much larger at a later stage.
... For Daphnia magna M., the critical concentrations found in the literature were 2,4-D = 25.0 mg L −1 (Toussaint et al. 1995 The evaluation factor values were set at 1000, according to the suggestion of the European Commission Technical Guidance Document and Guidelines for the Implementation of REACH ( 2006). The potential ecological risk (RQ i ) for each pesticide studied and potential ecological risk mix (RQ mix ) was quantified using the ratio between the measured environmental concentration and the predicted no effect concentration (Stehle and Schulz 2015;Di Lorenzo et al. 2018;Kienzler et al. 2019). The common risk ranking criteria are as follows: 0.01 < RQ < 0.1 is considered low risk, 0.1 < RQ < 1 is considered medium risk, and RQ > 1 is considered high risk (Hernando et al. 2006). ...
Article
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The total cultivated area in Brazil reached to 62 million ha in 2018, with the predominance of genetically modified soybean and corn (36 and 17 million ha, respectively) in no-tillage systems. In 2018, 5.3 × 10⁵ Mg of active ingredient of pesticides was applied in cropfields, representing about 7.3 L of commercial product by habitant. However, the monitoring of water courses contamination by pesticides remains scarce and is based on traditional grab sampling systems. In this study, we used the grab (water) and passive sampling (Polar Organic Chemical Integrative Sampler—POCIS) to monitor pesticide contamination in the river network of a representative agricultural catchment of southern Brazil. We selected 18 sampling sites located in tributaries and in the main course of the Guaporé River, in Rio Grande do Sul State, with different land use predominance including forest, urban, and agricultural areas. Altogether, 79 and 23 pesticides were, respectively, analyzed in water and POCIS samples. The water of Guaporé River and its tributaries were highly contaminated by many pesticides, especially by four herbicides (2,4-D, atrazine, deethyl-atrazine, and simazine), three fungicides (carbendazim, tebuconazole, and epoxiconazole), and one insecticide (imidacloprid). The amount, type, and concentration of pesticides detected were completely different depending on the sampling technic used. POCIS was effective to discriminate the contamination according to the main land use of each sampling site. The monitored areas with the predominance of soybean cultivation under no-tillage tended to have higher concentrations of fungicide, while in the more diversified region, the herbicides showed higher values. The presence of five herbicides used in corn and grassland forage production was correlated with areas of integrated crop-livestock systems, in contrast to higher contamination by 2,4-D in areas of intensive production of soybean and winter cereals.
... Pesticide authorization in the EU is under constant scrutiny for not providing a sufficient level of human health and environmental protection. For example, Stehle and Schultz (2015) and Zubrod et al. (2015) concluded that the EU risk assessment did not provide an adequate level of protection of aquatic ecosystems from insecticides and fungicides, respectively. Pesticide producers and farmers' organizations, on the other hand, complain about the loss of active ingredients, the difficulties in obtaining approval of new active ingredients, and timelines that are exceeded for many products. ...
Article
The glyphosate controversy before the renewal of the authorization of glyphosate in the European Union (EU) once again turned the spotlight on pesticide regulation in the EU. In the EU, pesticides are attracting more public attention than in other parts of the world, and many nongovernmental organizations specifically target pesticide regulation, trying to influence politicians and other decision makers. Following an overview of the EU pesticide legislation and the impact hitherto on EU agriculture, this paper outlines the glyphosate controversy and presents the outcome of desk studies conducted in Germany, the United Kingdom, France, and Sweden on the potential effects of a glyphosate ban on agricultural productivity and farm income. All studies concluded that the loss of income depends very much on farm type and cropping practice, but they all reached the conclusion that particularly no-tillage farming/conservation agriculture will be facing severe problems without glyphosate to control weeds and terminate cover crops. No-tillage/conservation agriculture is viewed as an effective strategy to prevent soil erosion and loss of nutrients, which could become larger problems without glyphosate. Other issues highlighted in the studies were the impact on resistance management, as glyphosate is largely seen as a “herbicide-resistance breaker.” Without glyphosate, fundamental changes in farming practices in the EU are required, and it is hard to imagine that they will come without a cost, at least in the short term.
... As in the study of Bjergager et al. (2017), it was possible to determine the threshold concentration below which proven synergists cease to act as synergists towards the aquatic crustacean D. magna, due to the use of more realistic concentration ranges. Taking into account that switch from antagonism to synergism occurred at concentration levels near the EC 50 isobole, no or only very slight synergistic interactions between individually occurring chlorpyrifos and terbuthylazine might be expected at the regulatory acceptable concentrations (RACs: 0.1 and 1.2 µg/L for chlorpyrifos and terbuthylazine, respectively; Stehle and Schulz 2015) and maximum acceptable concentration-environmental quality standards (MAC-EQSs: 0.1 and 1.3 µg/L for chlorpyrifos and terbuthylazine, respectively; EC 2013 and RIVM 2017) determined by a single substance risk assessment. Munkegaard et al. (2008) investigated whether interactions between selected organophosphate insecticides and herbicides can take place in the aquatic algae R. subcapitata and in the aquatic macrophyte L. minor. ...
Article
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In a regulatory perspective addressing the cumulative effect of co-occurring chemicals is the first and most important step in providing a more realistic hazard assessment of chemical cocktails to both man and environment. This study was conducted to show if joint effects on the immobilisation of the crustacean Daphnia magna and on the growth inhibition of algae Raphidocelis subcapitata follow additivity (concentration addition (CA) or independent action (IA) predictions) or if there is an interaction between chemicals in the organisms upon exposure to an environmentally realistic mixture of chlorpyrifos and terbuthylazine, with expected different molecular sites of action. A pattern of antagonism at lower doses and synergism at higher doses was found for acute immobility data, while no deviation from the additive conceptual models was observed in the algae inhibition test. Results in relation to the relevant set of regulatory acceptable concentrations (RACs) and environmental quality standards (EQSs) derived for individual chlorpyrifos and terbuthylazine were evaluated.
... The way this is incorporated in currently used fate models, such as those developed by the Forum for the Co-ordination of Pesticide Fate Models and Their Use (2001), to estimate predicted environmental concentrations (PECs) has also often been discussed (e.g., Knäbel et al. 2012;Rumschlag et al. 2019). Studies comparing PECs with measured environmental concentrations (MECs) have demonstrated that PECs generally underestimate MECs for insecticides (Knäbel et al. 2012;Stehle and Schulz 2015), particularly under Mediterranean conditions (Daam et al. 2011;Pereira et al. 2017). For example, Pereira et al. (2017) calculated PECs for chlorpyrifos under Mediterranean agricultural scenarios to be 1.8 to 2.6 µg L -1 , whereas their calculated 90th centile MEC was 2.9 µg L -1 . ...
Article
Chemical monitoring datasets such as those provided by the implementation of the Water Framework Directive (WFD) offer opportunities to evaluate the ecological risks of pesticides under large spatio‐temporal scales and to evaluate the protectiveness of the current prospective risk assessment framework. As a case study, we used the monitoring dataset for the insecticide chlorpyrifos (CPF) to perform a probabilistic risk assessment for Iberian surface water ecosystems. The specific objectives of the study were: (1) to assess the occurrence of CPF in relation to different agricultural production land uses, (2) to assess the spatio‐temporal variation in the exceedance of the European WFD short‐ and long‐term environmental quality standards (MAC‐EQS and AA‐EQS), and (3) to perform a probabilistic risk assessment for freshwater invertebrates. A database was analysed that contains CPF concentrations from 14600 surface water samples taken between 2012 and 2017 in the Iberian Peninsula (Spain and Portugal). CPF was detected in 21% of these samples. The MAC‐EQS was exceeded in 2% of the cases, while the AA‐EQS was exceeded in 18% of the cases. The majority of the exceedances took place in the littoral areas of the east and south‐east part of the Iberian Peninsula, particularly in areas with dominant citrus production during late‐spring, late‐summer and autumn. Our study indicates unacceptable risks posed by chlorpyrifos to Iberian surface waters over the study period, while it was approved for use in Europe. This study supports the need to perform further post‐registration monitoring assessments with other pesticides following similar approaches, which can help to identify possible pesticide misuse practices and improvements of the prospective risk assessment framework.
... The relevance of insecticides, e.g. those sprayed as pesticides, for aquatic ecosystems is not questioned, and indeed is reflected in risk assessment (Stehle and Schulz, 2015b). However, risks from plant-incorporated insecticides via GM crops are considered poorly in risk assessments and biosafety research. ...
Article
The aquatic environment is strongly connected to the surrounding agricultural landscapes, which regularly serve as sources of stressors such as agrochemicals. Genetically modified crops, which are cultivated on a large scale in many countries, may also act as stressors. Despite the commercial use of genetically modified organisms (GMOs) for over 20years, their impact on the aquatic environment came into focus only 10years ago. We present the status quo of the available scientific data in order to provide an input for informed aquatic risk assessment of GMOs. We could identify only 39 publications, including 84 studies, dealing with GMOs in the aquatic environment, and our analysis shows substantial knowledge gaps. The available information is restricted to a small number of crop plants, traits, events, and test organisms. The analysis of effect studies reveals that only a narrow range of organisms has been tested and that studies on combinatorial actions of stressors are virtually absent. The analysis of fate studies shows that many aspects, such as the fate of leached toxins, degradation of plant material, and distribution of crop residues in the aquatic habitat, are insufficiently investigated. Together with these research needs, we identify standardization of test methods as an issue of high priority, both for research and risk assessment needed for GMO regulation.
... It is therefore recommended that risk managers motivate their choice on the basis of a risk-benefit analysis and for risk assessors to document the analysis of the environmental consequences of the choice of the 90th percentile. In addition, Stehle and Schulz (2015) claim that 44.7% of the 1,566 cases of measured insecticide concentrations in EU surface waters exceeded their respective RAC. This either suggests flaws in the prospective exposure assessment of PPPs (e.g. ...
Article
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The EFSA performs environmental risk assessment (ERA) for single potential stressors such as plant protection products, genetically modified organisms and feed additives, and for invasive alien species that are harmful to plant health. This ERA focusses primarily on the use or spread of such potential stressors in an agricultural context, but also considers the impact on the wider environment. It is important to realise that the above potential stressors in most cases contribute a minor proportion of the total integrated pressure that ecosystems experience. The World Wildlife Fund listed the relative attribution of threats contributing to the declines in animal populations as follows: 37% from exploitation (fishing, hunting, etc.), 31% habitat degradation and change, 13% from habitat loss, 7% from climate change, and only 5% from invasive species, 4% from pollution and 2% from disease. In this scientific opinion, the Scientific Committee gathered scientific knowledge on the extent of coverage of endangered species in current ERA schemes that fall under the remit of EFSA. The legal basis and the relevant ecological and biological features used to classify a species as endangered are investigated. The characteristics that determine vulnerability of endangered species are reviewed. Whether endangered species are more at risk from exposure to potential stressors than other non-target species is discussed, but specific protection goals for endangered species are not given. Due to a lack of effect and exposure data for the vast majority of endangered species, the reliability of using data from other species is a key issue for their ERA. This issue and other uncertainties are discussed when reviewing the coverage of endangered species in current ERA schemes. Potential tools, such as population and landscape modelling and trait-based approaches, for extending the coverage of endangered species in current ERA schemes, are explored and reported.
... Cela va à l'encontre des efforts mondiaux de protection de la biodiversité et, en particulier, des objectifs de la réglementation de l'UE sur les pesticides (Parliament, 2009). Les dépassements constants des seuils réglementaires (Stehle & Schulz, 2015 ;Schäfer et al., 2019) et les révisions des autorisations de pesticides, tels que les néonicotinoïdes dans l'UE, attestent de lacunes en matière de réglementation et usages des pesticides. La réglementation des pesticides devrait être basée sur des preuves scientifiques solides et actualisées, selon lesquelles les produits présentant des effets inacceptables sur l'environnement ne seraient pas acceptés pour les utilisateurs (Sgolastra et al., 2020). ...
Thesis
Les microplastiques (MP) sont largement répandus dans les zones côtières et les océans du monde entier. Les MP sont préoccupants sur le plan environnemental en raison de leurs impacts potentiels sur un large éventail d’organismes marins, de sorte que l'évaluation de leur impact sur les écosystèmes est devenue une priorité de recherche. En complément, les substances phytosanitaires utilisées régulièrement en agriculture se déversent dans les milieux côtiers, par ruissellements. Ces travaux de thèse se sont focalisés sur (i) une étude exploratoire d’un site pilote des Pertuis Charentais (PC) afin d’évaluer l’importance de la contamination plastique et pouvoir évaluer leur toxicité sur (ii) les stades précoces et (iii) tardifs de développement de l’huître creuse, Crassostrea gigas. Ces travaux fournissent une première investigation de l’état de contamination plastique (macro et micro) d’un site d’étude littoral des PC, où la présence de plastiques ostréicoles ainsi que des concentrations élevées en MP dans les sédiments de plage ont été identifiés. De plus, les expérimentations menées en conditions de laboratoire contrôlées, nous informent sur le caractère toxique des MP de PE et des pesticides sur les stades précoces de développement (embryo-larvaire) de l’huitre creuse. Les pesticides dosés dans les eaux des PC ont montré des effets significatifs à des concentrations proches de l’environnement naturel alors que les MP s’avèrent toxiques pour des concentrations plus fortes. Ces effets apparaissent sur le développement, la croissance et le comportement natatoire des larves d’huitre creuse. Des expérimentations complémentaires, effectuées sur des stades plus tardifs, notamment les naissains d’huitre creuse, ont permis de montrer un comportement valvaire modifié suite à une exposition de 25 jours aux MP de type PE et au Chlortoluron, en conditions de laboratoire. Les effets intergénérationnels ont pu être observés avec l’utilisation de MP environnementaux (cocktail de PE, PP et PVC), vieillis aux abords des concessions ostréicoles. La qualité et le succès de fécondation ont été modifiés ainsi que le développement et le comportement de nage des larves-D issues de parents préalablement exposés durant deux mois. Ces premiers résultats permettront de renforcer les connaissances de la communauté scientifique et d’informer les professionnels et acteurs conchylicoles sur les risques des contaminants émergents, tels que les MP et les pesticides. Des adaptations des pratiques conchylicoles seront nécessaires afin d’éviter une probable dégradation de la qualité des eaux littorales dans les PC.
... They observed that about 25% of the soil samples examined contained one residue and 58% of the samples contained more than one residue. As evidenced by other research(Stehle & Schulz, 2015), among the substances that most frequently exceed the limits allowed by law, there are glyphosate and neonicotinoids. ...
... In contrast to other pesticides, insecticides regularly occur in surface waters for rather short time periods spanning a few hours up to a few days (Stehle et al., 2013), which is sufficient to cause negative effects in aquatic ecosystems due to their often fast uptake and presence at their site of action (Tang & Siegfried, 1995). When following standard risk assessment procedures, insecticides have by far the highest ecotoxicological potential among all pesticide types, with aquatic invertebrates being the most sensitive group of organisms (Malaj et al., 2014;Stehle et al., 2011;Stehle & Schulz, 2015b). Often the single most toxic insecticide within a mixture drives entirely the predicted aquatic toxicity (Wolfram et al., 2019). ...
Chapter
The ecosystem process of organic matter decomposition (OMD) in fresh waters is realised by a complex interaction among different groups of microorganisms (including bacteria and fungi) and detritivorous animals. As a consequence of this multi-level interaction, biotic (e.g., competition, predation) and abiotic (e.g., flow, temperature, toxicants) factors may influence the performance of either (micro)organism group with potential feedback to detritivores, and in turn OMD. In this chapter, we discuss how the abiotic factor toxicants affects OMD. We organised the chapter along a conceptual model that pinpoints groups of organisms and their interactions, which are critical for OMD. We focus on four toxicant classes (i.e., fungicides, antibiotics, insecticides and metals) that specifically affect fungi, bacteria or detritivorous invertebrates or have a broad activity spectrum. We summarize the effects caused by these toxicant classes on relevant groups of organisms, which are often determined by the toxicant mode of action. On this basis, we develop effect pathways leading to alterations in OMD dynamics. Finally, we discuss whether and how these effect pathways may support the interpretation of effect patterns observed under (semi-)field conditions and highlight research gaps we suggest addressing in order to improve understanding and prediction power.
... EDS with a total n = 296 from agricultural streams revealed RAC exceedances in 59%, grab samples with a total n = 440 in 26% of samples. This is similar to the results obtained by the most comprehensive meta-study to date, which found that 45% of the 1566 cases of measured insecticide concentrations in EU surface waters exceeded their respective RACs ( Stehle and Schulz, 2015 ). On the substance level, 37 pesticides and 2 metabolites exceeded their RAC ( Fig. 2 B, for the 20 pesticides with most exceedances, Tab. ...
Article
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Despite elaborate regulation of agricultural pesticides, their occurrence in non-target areas has been linked to adverse ecological effects on insects in several field investigations. Their quantitative role in contributing to the biodiversity crisis is, however, still not known. In a large-scale study across 101 sites of small lowland streams in Central Europe, Germany we revealed that 83% of agricultural streams did not meet the pesticide-related ecological targets. For the first time we identified that agricultural nonpoint- source pesticide pollution was the major driver in reducing vulnerable insect populations in aquatic in- vertebrate communities, exceeding the relevance of other anthropogenic stressors such as poor hydro- morphological structure and nutrients. We identified that the current authorisation of pesticides, which aims to prevent unacceptable adverse effects, underestimates the actual ecological risk as (i) measured pesticide concentrations exceeded current regulatory acceptable concentrations in 81% of the agricultural streams investigated, (ii) for several pesticides the inertia of the authorisation process impedes the incor- poration of new scientific knowledge and (iii) existing thresholds of invertebrate toxicity drivers are not protective by a factor of 5.3 to 40. To provide adequate environmental quality objectives, the authorisa- tion process needs to include monitoring-derived information on pesticide effects at the ecosystem level. Here, we derive such thresholds that ensure a protection of the invertebrate stream community.
... For example, a study looking at pesticides in watercourses across the European Union (EU) found 135 different pesticides, consisting of 66 insecticides, 42 herbicides, and 27 fungicides. Of all the samples tested, around 90% of samples had mixtures of pesticides, containing almost 13 different pesticides inside (Stehle & Schulz, 2015). The distribution of pesticides in groundwater and surface waters may also vary in quantity. ...
Chapter
Pesticides are necessary to support the agricultural industry in order to feed the world’s growing population. However, excessive application of them has led to contamination of soils and bodies of water all around the globe, threatening many organisms in these ecosystems. Pesticide persistence in the environment has resulted in significant harmful effects for a long period and has caused accumulation of pesticides. This chapter provides information about the dangerous effects of pesticide mixtures due to their synergistic responses; and an environmentally friendly method called bioremediation that uses microorganisms or plants to degrade pesticides. Many studies have shown the efficacy of this method, leading to many large-scale applications in the field. Even though many advantages of bioremediation have been documented, some challenges are still open for improvement in the future.
... [26] When compared to other classes, pyrethroids have toxicity and low residual power in the environment, [27] but have extremely high toxicity in non-target invertebrates. [28,29] Strobilurins, which are natural antibiotics, are found in fungi and have a rapid degradation in the environment. [30,31] Despite this, the concentrations of these contaminants in water are low, which requires the use of robust and highly sensitive analytical techniques such as Gas Chromatography (GC), which allows to achieve better results with lower limits of detection (LOD) and quantification (LOQ). ...
Article
The determination of some pesticides in surface sediments can provide important information about their distribution in the water column. This work aimed to determine the distribution of the classes of pesticides along the Ondas River’s hydrographic basin (ORHB), in eighteen different points, during the dry and rainy periods. The pesticides were extracted from the sediment samples by solid-liquid extraction and then analyzed using a gas chromatograph coupled to mass spectrometry. After the development and validation of the method, nineteen pesticides from the group of organochlorine, organophosphates, carbamate and thiocarbamate, pyrethroids, and strobilurins were quantified in at least one point in the two collection periods, with accuracy varying between 86 and 126%. The average concentrations were 0.020 ng g-1 (carbofuran) to 249.123 ng g-1 (dimethoate) and 0.029 ng g-1 (carbofuran and sulfotep) to 533.522 ng g-1 in the dry and rainy periods, respectively. The results showed a wide distribution of pesticide residues in the ORHB, with higher levels for dimethoate, phenitrothion, and malathion, which may be related to their agricultural use in the region. In Brazil, it does not have specific legislation for maximum permitted values of pesticides in sediment, allowing for inappropriate or prohibited use and, consequently, affecting water quality.
... Anthropogenic activities are responsible for river pollution in most countries [4,5]. For example, the potash industry was the primary anthropogenic source of salts in rivers in Germany, with the dominant ions being Cl − , PO 4 3− , Na + , Mg 2+ , and SO 4 2− [6,7]; pesticide residues and nutrients runoff from agriculture activities to surface water also threaten freshwater biodiversity in the European Union [8,9]; pesticides development history and water quality monitoring data [46]. Multivariate statistical methods (cluster analysis and principal component analysis) were applied to investigate the spatial and seasonal (dry and rainy season) variations of water quality parameters and identify their main drivers. ...
Article
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Temporal and spatial water quality data are essential to evaluate human health risks. Understanding the interlinking variations between water quality and socio-economic development is the key for integrated pollution management. In this study, we applied several multivariate approaches, including trend analysis, cluster analysis, and principal component analysis, to a 15-year dataset of water quality monitoring (1999 to 2013) in the Thi Vai estuary, Southern Vietnam. We discovered a rapid improvement for most of the considered water quality parameters (e.g., DO, NH4, and BOD) by step trend analysis, after the pollution abatement in 2008. Nevertheless, the nitrate concentration increased significantly at the upper and middle parts and decreased at the lower part of the estuary. Principal component (PC) analysis indicates that nowadays the water quality of the Thi Vai is influenced by point and diffuse pollution. The first PC represents soil erosion and stormwater loads in the catchment (TSS, PO4, and Fetotal); the second PC (DO, NO2, and NO3) determines the influence of DO on nitrification and denitrification; and the third PC (pH and NH4) determines point source pollution and dilution by seawater. Therefore, this study demonstrated the need for stricter pollution abatement strategies to restore and to manage the water quality of the Thi Vai Estuary.
... To compare the effects of different chlorpyrifos concentrations, we included two higher concentrations: 0.34 mg/L and 0.36 mg/L, which caused~27% and~38% mortality in the range finder, respectively. These chlorpyrifos concentrations are ecologically relevant as these are within the range measured in European surface waters: 95% CI ¼ [0.07 mg/L, 0.69 m/L] (Stehle and Schulz, 2015;personal communication Sebastian Stehle). Note that these three concentrations are close, yet generate considerably different mortality due to the steep dose-response curve of chlorpyrifos in the study species (see the results of the range finder in Appendix A). ...
Article
Despite the increased attention for temporal aspects of stressor interactions and for effects of warming in ecotoxicological studies, we lack knowledge on how different exposure durations to warming may affect pesticide sensitivity. We tested how three types of exposure duration to 4 °C warming (acute, developmental and transgenerational exposure to 24 °C vs 20 °C) shape the effect of the pesticide chlorpyrifos on two ecologically relevant fitness-related traits of mosquito larvae: heat tolerance and antipredator behaviour. Transgenerational (from the parental generation) and developmental (from the egg stage) warming appeared energetically more stressful than acute warming (from the final instar), because (i) only the latter resulted in an adaptive increase of heat tolerance, and (ii) especially developmental and transgenerational warming reduced the diving responsiveness and diving time. Exposure to chlorpyrifos decreased the heat tolerance, diving responsiveness and diving time. The impact of chlorpyrifos was lower at 24 °C than at 20 °C indicating that the expected increase in toxicity at 24 °C was overruled by the observed increase in pesticide degradation. Notably, although our results suggest that transgenerational warming was energetically more stressful, it did reduce the chlorpyrifos-induced negative effects at 24 °C on heat tolerance and the alarm escape response compared to acute warming. Our results provide important evidence that the exposure duration to warming may determine the impact of a pesticide under warming, thereby identifying a novel temporal aspect of stressor interactions in risk assessment.
... The three concentrations cover a narrow range but induced considerable differences in mortality because of the steep dose-response curve of chlorpyrifos in the study species (see in the companion study Meng et al., 2021; see also Delnat et al., 2021). The chosen concentrations are environmentally realistic as they are within the range of measured chlorpyrifos concentrations in European surface waters (Stehle and Schulz, 2015). The measured chlorpyrifos concentrations in the experimental vials for the three nominal concentrations were 0.262 ± 0.021 (mean ± SE), 0.297 ± 0.037, and 0.345 ± 0.023 μg/L at the start of the exposure. ...
Article
There is increasing awareness that the toxicity of pesticides can to a large extent be modulated by warming, and that temporal exposure scenarios may strongly affect the impact of two stressors. Nevertheless, we lack information on how the exposure duration to warming may shape pesticide toxicity under warming. Furthermore, despite that bioenergetic responses have the potential to generate mechanistic insights in how toxicants interact with warming, this has been understudied in ecotoxicology. To investigate whether warming duration modifies pesticide toxicity, mosquito larvae were exposed to a control temperature at 20 °C or three warming treatments at 24 °C (acute, developmental and transgenerational warming), and to four pesticide treatments (solvent control, and three chlorpyrifos concentrations) in a full factorial design. Chlorpyrifos increased mortality, growth rate and the energy consumed, and reduced the AChE (acetylcholinesterase) activity, the energy available, and the net energy budget (estimated as cellular energy allocation). The warming treatments did not affect mortality, AChE activity, and the energy consumed. However, acute warming increased the growth rate and decreased the energy available, while both acute and developmental warming decreased the cellular energy allocation. A first key finding was that the lethal and sublethal effects of chlorpyrifos were less strong under warming because of a higher degradation in the medium under warming. A second key finding was that, among the warming treatments, the pesticide toxicity was more increased under acute warming than under transgenerational warming. This could be explained by the negative impact of acute warming but not transgenerational warming on the net energy budget. The results in this study provide mechanistic insights that the exposure duration to warming can play an important role in modulating the impact of pesticides under warming. Therefore, including ecologically relevant temporal scenarios of exposure to warming is important in ecotoxicological studies.
Technical Report
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The pilot study “Kleingewässermonitoring” was successfully implemented as a two-year monitoring program on residues of plant protection products (PPPs) in small streams. The chemical pollution and biological status of small streams in the agricultural landscape was investigated in-depth between April and July for more than 100 stream sections in 13 federal states in Germany. In addition to grab water samples according to the Water Framework Directive (WFD), event-based water samples were taken. The event-based water samples represent short-term pulse concentrations of pesticide residues following precipitation events. Also passive samplers (Chemcatcher and Sorb-Star) were exposed over three-week periods to obtain time-weighted average (background) concentrations of pesticides. Other anthropogenic stressors such as poor structural quality, nutrients, and oxygen depletion were also recorded in high resolution for the whole data set. The biological investigations included sampling of the aquatic invertebrate community and the algal community as well the ecosystem functions in the small streams. The results of the “Kleingwässermonitoring” show that the RAK values (Regulatory Acceptable Concentrations) from the authorization process for PPPs were exceeded for at least one active substance at over 73 % of the sites investigated. In particular, event-based samples showed high concentrations, which would not have been detected by the regular grab sampling. The revealed pollution resulting from the use of PPPs, correlates with the ecological quality of the water bodies. Findings of the bio indicator SPEARpesticides show that the majority (over 80 %) of the small streams in the German agricultural landscape fails a good ecological status. The “Kleingewässermonitoring” confirms that a realistic assessment of PPP contamination in small streams needs to include exposure peaks caused by precipitation events if results should be used for regulatory consequences. The pilot study revealed, that existing thresholds for PPP residues are regularly exceeded in small streams in Germany, even though PPP authorization is complex and often criticized as over-conservative by industry and farmers. Furthermore, ecological effects even if pollution is below these thresholds indicate, that regulatory thresholds derived from laboratory studies may not always be protective for field conditions. The data from this pilot study can be used to derive measures to reduce pollution of small streams by PPP use in the future.
Article
While interactions with global warming and multigenerational effects are considered crucial to improve risk assessment of pesticides, these have rarely been studied in an integrated way. While heat extremes can magnify pesticide toxicity, no studies tested how their combined effects may transmit to the next generation. We exposed mosquito larvae in a full factorial, two-generation experiment to a heat spike followed by chlorpyrifos exposure. As expected, the heat spike magnified the chlorpyrifos-induced lethal and sublethal effects within both generations. Only when preceded by the heat spike, chlorpyrifos increased mortality and reduced the population growth rate. Moreover, chlorpyrifos-induced reductions in heat tolerance (CTmax), acetylcholinesterase (AChE) activity and development time were further magnified by the heat spike. Notably, when parents were exposed to chlorpyrifos, the chlorpyrifos-induced lethal and sublethal effects in the offspring were smaller, indicating increased tolerance to chlorpyrifos. In contrast, there was no such multigenerational effect for the heat spike. Despite the adaptive multigenerational effect to the pesticide, the synergism with the heat spike was still present in the offspring generation. Generally, our results provide important evidence that short exposure to pulse-like global change stressors can strongly affect organisms within and across generations, and highlight the importance of considering multigenerational effects in risk assessment.
Article
Signed in 2009, the plant protection Commission Regulation EC No 1107/2009 created a new category of active substances, the low-risk substances, with specific status defined in Article 22. The initial and specific criteria, not suitable for microorganisms and natural substances , were modified in 2018, and the first low-risk substance, allocating Part D of Regulation EC No 540/2011, was granted in the same year. Since then, thirty-three low-risk substances have been granted with this specific status through approvals and renewals, while a larger list of potential low-risk substances from already-approved active substances was published. This list is only exploited during renewals, and this process would take another five years to complete. After four years of the implementation of this status, the number of such substances is still low, but is intended to increase slowly. Two more low-risk substances are already pending in 2021, which will bring the number of low-risk substances to thirty-five, while the initial list of potential low-risk substances (only renewals) included fifty-seven substances.
Article
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Present-day agricultural crop protection relies heavily on synthetic pesticides, which are known to adversely affect the environment and human health. As remediation, European agricultural policies strive for a transition to low-pesticide agriculture. However, these policy efforts have so far shown limited success. We argue that neglecting the diversity of the according routinized practices belongs to the reasons for that limited success. We specifically investigate how farmers' current local crop protection practices differ. Methodologically, the article is based on semi-structured interviews with farmers and crop protection experts as well as on qualitative data from a survey among Swiss farmers. Using practice theory to analyze our data, we identify the meanings, materials and competences in farmers’ practice narratives. From our analysis, five types of routinized crop protection practice emerge, revealing a picture of diversity, also in their responses to current incentive-based agri-environmental policy instruments. This diversity cannot be accommodated by a one-size-fits-all policy approach but rather requires a balanced mix, for example of command-and-control instruments, financial incentives and extension services.
Article
Historically, pesticides have shaped and revolutionized modern agriculture in successions and thus have played a major role in increasing agricultural productivity with a substantial reduction in losses and increased farm incomes. Fresh produce like vegetables is attacked by a large number of insects and pests which necessitates the use of pesticides as control agents and may result in direct toxicity or residue left in treated vegetables after the harvest. The issues of contamination and residues have an unavoidable threat to both the environment and human well-being. Different adverse health effects due to pesticide exposure or consumption through the contaminated food depend upon the type of pesticide and exposure duration as well. The use of pesticides should be restricted by appropriate and good agricultural practices (GAPs), rational use for specific target organisms, and alternative pest control strategies to reduce their health and environmental impact. Regulations governing pesticide use, training, and extension services should be given to the farmers. The biotransformation and bioaccumulation of the most commonly used pesticides should be carefully monitored and documented for the highest level of safety to the ultimate consumers. Further, research should be focused on searching for rapid analytical, detection, and removal techniques for the residues. The focus of this review is to provide updated information about the most commonly used pesticides and their bioaccumulation and biotransformation. Further, advancements in the detection techniques and the effect of processing or decontamination techniques on residue content in vegetable crops have been provided for the readers.
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The decades-long agricultural use of insecticides resulted in frequent contamination of surface waters globally regularly posing high risks for the aquatic biodiversity. However, the concentration levels of individual insecticide compounds have by now not been compiled and reported using global scale data, hampering our knowledge on the insecticide exposure of aquatic ecosystems. Here, we specify measured insecticide concentrations (MICs, comprising in total 11,300 water and sediment concentrations taken from a previous publication) for 28 impor- tant insecticide compounds covering four major insecticide classes. Results show that organochlorine and organ- ophosphate insecticides, which dominated the global insecticide market for decades, have been detected most often and at highest concentration levels in surface waters globally. In comparison, MICs of the more recent py- rethroids and neonicotinoids were less often reported and generally at lower concentrations as a result of their later market introduction and lower application rates. An online insecticide classification calculator (ICC; avail- able at: https://static.magic.eco/icc/v1) is provided in order to enable the comparison and classification of pro- spective MICs with available global insecticide concentrations. Spatial analyses of existing data show that most MICs were reported for surface waters in North America, Asia and Europe, whereas highest concentration levels were detected in Africa, Asia and South America. An evaluation of water and sediment MICs showed that theo- retical organic carbon-water partition coefficients (KOC) determined in the laboratory overestimated KOC values based on actual field concentrations by up to a factor of more than 20, with highest deviations found for highly sorptive pyrethroids. Overall, the comprehensive compilation of insecticide field concentrations presented here is a valuable tool for the classification of future surface water monitoring results and serves as important input data for more field relevant toxicity testing approaches and pesticide exposure and risk assessment schemes.
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The contamination of water with pesticides used in agriculture and urban areas is a priority issue that is currently of global concern. In 2015 the European Union (EU) published the first Watch List (1st WL), which showed the necessity for Union‐wide monitoring of ten organic substances/groups of substances in the field of water policy. The list includes, among other items, eight pesticides: five neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam), and methiocarb, oxadiazon and tri‐allate. In 2018 the EU published the second Watch List, which repealed the 1st WL. In this list, among other changes, one pesticide — metaflumizone was added, and two (oxadiazon and tri‐allate) were removed. This review summarises the current state of knowledge on the reported occurrence and concentrations of these pesticides in surface and groundwaters and in effluents from wastewater treatment plants derived from 73 studies in 21 countries worldwide. Imidacloprid, acetamiprid and thiamethoxam were the most frequently found pesticides due to their widespread use, while metaflumizone, methiocarb, oxadiazon and tri‐allate are less studied pesticides whose occurrence in water is also poorly reported. More investigation is needed to assess the occurrence and impact of these pesticides on the aquatic environment worldwide in the context of water supply and human security.
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Die Pilotphase Kleingewässermonitoring konnte als drittes Teilvorhaben zur „Umsetzung des Nationalen Aktionsplan zur nachhaltigen Anwendung von Pflanzenschutzmitteln (PSM)“ erfolgreich als zweijähriges Monitoring umgesetzt werden. Es wurden für mehr als 100 Fließgewässerabschnitte in 13 Bundesländern umfassend der chemische und biologische Zustand kleiner Fließgewässer in der Agrarlandschaft zwischen April und Juli erfasst. Zusätzlich zu Schöpfproben analog zu dem behördlichen Monitoring nach Wasserrahmenrichtlinie (WRRL) wurden ereignisbasierte Wasserproben genommen, um kurzfristige Peakkonzentrationen infolge von Niederschlägen zu erfassen. Zudem wurden anthropogene Stressoren wie Gewässerstruktur, Nährstoffe und Sauerstoffdefizite hochaufgelöst aufgenommen. Die biologische Untersuchung umfasste die Beprobung der aquatischen Invertebraten- und Algengemeinschaft sowie eine Untersuchung der Ökosystemfunktion in den Kleingewässern. Die Ergebnisse zeigen, dass die im Rahmen des Zulassungsverfahrens von PSM festgelegten RAK-Werte (Regulatorisch Akzeptablen Konzentrationen) an über 73 % der untersuchten Standorte für mindestens einen PSM-Wirkstoff überschritten wurden. Besonders die Ereignisproben infolge von Regenereignissen wiesen erhöhte Konzentrationen auf, die durch Schöpfproben nicht erfasst wurden. Diese Belastungen korrelieren auch mit der ökologischen Situation der Gewässer. So erfüllt der Großteil (über 80 %) der untersuchten Fließgewässerabschnitte anhand des SPEARpesticides-Index nicht die Qualitätskriterien für einen guten Zustand. Die Pilotphase Kleingewässermonitoring zeigt, dass eine realistische Bewertung und regulatorische Nutzung eines Monitorings von PSM-Rückständen in kleinen Gewässern nur dann erfolgen kann, wenn auch erhöhte Einträge infolge von Niederschlagsereignissen berücksichtigt werden. Weiterhin treten auch unterhalb der bestehenden RAK-Werte ökologische Effekte im Gewässer auf, so dass sich die Frage nach der Protektivität der aus Labordaten abgeleiteten RAK-Werte stellt. Die Daten der ermittelten PSM-Belastung der kleinen Gewässer in der Agrarlandschaft werden dazu beitragen, Ursachen für die regelmäßige Überschreitung der bestehenden Grenzwerte zu ermitteln und Schwächen der bisherigen Risikobewertung aufzudecken. Ziel wird sein, auf dieser Basis Möglichkeiten zur Reduzierung der Einträge zu erarbeiten und regulatorische Konsequenzen zu ziehen. Siehe dazu auch Liess et al. (2021) und Weisner et al. (2021).
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Pesticide applications in agricultural crops often comprise a mixture of plant protection products (PPP), and single fields face multiple applications per year leading to complex pesticide mixtures in the environment. Restricted to single PPP, the current European Union PPP regulation, however, disregards the ecological risks of pesticide mixtures. To quantify this additional risk, we evaluated the contribution of single pesticide active ingredients to the additive mixture risk for aquatic risk indicators (invertebrates and algae) in 464 different PPP used, 3446 applications sprayed and 830 water samples collected in Central Europe, Germany. We identified an average number of 1.3 different pesticides in a single PPP, 3.1 for complete applications often involving multiple PPP and 30 in stream water samples. Under realistic worst-case conditions, the estimated stream water pesticide risk based on additive effects was 3.2 times higher than predicted from single PPP. We found that in streams, however, the majority of regulatory threshold exceedances was caused by single pesticides alone (69% for algae, 81% for invertebrates). Both in PPP applications and in stream samples, pesticide exposure occurred in repeated pulses each driven by one to few alternating pesticides. The time intervals between pulses were shorter than the 8 weeks considered for ecological recovery in environmental risk assessment in 88% of spray series and 53% of streams. We conclude that pesticide risk assessment should consider an additional assessment factor to account for the additive, but also potential synergistic simultaneous pesticide mixture risk. Additionally, future research and risk assessment need to address the risk from the frequent sequential pesticide exposure observed in this study.
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Awareness of the presence of high concentrations of pesticides in Swiss rivers has increased in the last decade. Since 2017, the Federal Department of the Environment, Transport, Energy and Communications is planning to introduce new regulatory acceptable concentrations for surface water of 38 organic pesticides. Based on pesticide concentration analyses carried out in a small agricultural catchment in the canton of Vaud, over the 2005–2015 period, we review the impacts of this legislative revision on the chemical status of rivers. A first comparison between the historical standard (0.1 μg/L) and revised water quality criteria (WQC) highlights that standards are raised for 12 pesticides and lowered for 25 pesticides, sometimes with very high ratios. Risk coefficients were computed based on the historical standard and revised WQC to determine the chemical status of the river. The worst‐case value was retained to define this status. Individual risk coefficients indicate that more pesticides meet the revised WQC than the historical one, leading to very different chemical status. According to the historical standard, the chemical status of the Boiron River is defined as moderate to poor, and the main problem is the presence of herbicides. According to the revised WQC, the chemical status is good, and periodically moderate or poor. Ninety percent of the pesticides identified had a low to very low ecotoxicological risk coefficient. Other issues related to insecticides were identified. Based on these results, we discuss the importance of the standard chosen when defining regulatory acceptable concentrations. This article is categorized under: Water and Life > Conservation, Management, and Awareness Science of Water > Water Quality Engineering Water > Sustainable Engineering of Water A suggestion for 38 new water quality criteria for pesticides led us to analyze their impacts on the classification of the chemical status of a river in a Swiss canton. We discuss revision of the standards and recommend them as long as ecosystem protection is guaranteed and demonstrated.
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Pesticide impacts are usually discussed in the context of applied amounts while disregarding the large but environmentally relevant variations in substance-specific toxicity. Here, we systemically interpret changes in the use of 381 pesticides over 25 years by considering 1591 substance-specific acute toxicity threshold values for eight nontarget species groups. We find that the toxicity of applied insecticides to aquatic invertebrates and pollinators has increased considerably—in sharp contrast to the applied amount—and that this increase has been driven by highly toxic pyrethroids and neonicotinoids, respectively. We also report increasing applied toxicity to aquatic invertebrates and pollinators in genetically modified (GM) corn and to terrestrial plants in herbicide-tolerant soybeans since approximately 2010. Our results challenge the claims of a decrease in the environmental impacts of pesticide use.
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The model SYNOPS was developed to calculate national risk indicators for assessing the aquatic and terrestrial risk potential of pesticides in Germany. For Switzerland, a national aquatic risk indicator is currently being developed based on SYNOPS. It aims at evaluating long-term trends in aquatic risks based on changing pesticide usage and risk mitigation measures. In a first step, parameters of the fate models of SYNOPS were parametrized for the Swiss geographical context. Apart from data about pesticides and their specific usage, SYNOPS requires information about climate, soil and site-specific properties and crop stage. Based on these inputs, SYNOPS calculates the predicted environmental concentrations (PEC) of pesticides in water bodies and the associated exposure-toxicity-ratios (i.e., risks). To consider the effects of risk mitigation measures in risk indicators, a realistic representation of the contribution of different routes of entry (run-off, erosion, drainage, drift) is essential. To parametrize SYNOPS, a sensitivity analysis of the aquatic transport and fate models of SYNOPS was conducted: realistic ranges of Swiss-specific parameters and their combinations were defined and used as input for the sensitivity analysis. The impacts of input parameters on total PEC values and on the contribution of different routes of entry were analyzed. The sensitivity analysis revealed that slope and KOC were the parameters with the highest impact on pesticide concentration and that run-off was the dominant route of entry in most tested scenarios. From over 40,000 tested environmental scenarios, a reduced set of 75–113 environmental scenarios was finally selected, which predicted similar PEC values and comparable contributions of different routes of entry compared with the full set. With the parametrization and reduction of used environmental scenarios, fate calculations became more efficient and realistic for Swiss conditions. The findings of this study provide a solid basis for developing a national aquatic risk indicator using SYNOPS.
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Crop protection and biodiversity in agro-ecosystems The Scientific Advisory Board for the National Action Plan on the Sustainable Use of Plant Protection Products (NAP) advises the German Federal Ministry of Food and Agriculture (BMEL). The Board has provided its opinion on the impact of crop protection on biodiversity in agro-ecosystems. This publication is based on the Board‘s position. Crop protection safeguards crop yields and crop quality in arable farming, and especially in the production of specialty crops. Global meta-analyses and expert assessments estimate the potential yield loss due to pests and diseases to be in the order of 17 to 40%, depending on the crop species. These losses are reduced through the use of direct chemical, biological or physical crop protection, and by means of indirect, systematic, preventative measures. Out of the many effects of crop pesticides, their impact on biodiversity is difficult to grasp. Current intensive farming is geared towards efficiency and global competitiveness. It is bringing about multicausal changes in landscapes and ecosystems, reducing the diversity of natural habitats and agroecosystems, and is thus adversely impacting on the biodiversity of numerous groups of species. At the same time, climate change is having a negative impact on biodiversity within the agricultural landscape. The decline in biodiversity within the agricultural landscape is striking. Populations of butterflies and birds, for example, have declined by 50% since 1990 and 1980 respectively, and the biomass of flying insects has fallen by 75% since 1989. Species diversity and the abundance of arable weeds, amphibians, fish, sensitive aquatic invertebrates, wild bees, hover flies, carabids, ladybirds and many other groups of organisms are on the decline. Out of the 14 open habitat types in Germany that are immediately dependent on land-use management, 80% are at risk. Other habitat types (peatland, woodland, shorelines, meadows etc.) are adversely impacted by nearby agricultural land. The direct and indirect consequences of crop pesticides have been documented in a large number of scientific studies conducted in Germany and Europe. The use of pesticides (insecticides, fungicides, herbicides) is a significant factor within the complex overall range of factors impacting on biodiversity in agro-ecosystems. It mostly has significant negative consequences, although a positive impact has been observed in exceptional cases. Crop pesticides end up in and on plants, animals and the soil, in the atmosphere, as well as in water and the groundwater. Their harmful side-effects can manifest quickly or over long periods of time. They can be directly toxic to non-target organisms and indirectly reduce the food supply and habitats for a wide range of different organisms. Moreover, there are also cumulative and sequential impacts, as crop pesticides are often applied together and the combined impact of environmental stressors and crop pesticides is particularly relevant where pesticides are used on open land. The NAP Scientific Advisory Board therefore proposes the following measures for sustainable crop protection: 1. A representative, comprehensive, long-term biodiversity monitoring scheme should be introduced which focuses on the impact of crop pesticides and provides for standardised assessments of further changes in biodiversity. 2. Based on the latest state of knowledge, crop pesticide approval processes should be reviewed with a view to identifying potential gaps in the assessment of impacts on biodiversity, and the resultant findings should be taken into account in amendments to EU legislation governing the approval of pesticides. 3. Both positive and negative incentives for farming practice should be created with a view to reducing the use of pesticides in farming. Moreover, the feasibility of a levy on crop pesticides should be investigated, and a science-based system for the internalisation of environmental costs (True Cost Accounting) should be proposed over the medium term. 4. Integrated crop protection methods should be encouraged through research and consultancy; whilst there should be a focus on pest-tolerant and disease-tolerant or resistant species in plant breeding. 5. The framework conditions for organic agriculture should be further improved with a view to achieving the Federal Government‘s objective to extend the area under organic management to 20% of the agricultural area as soon as possible. 6. In the context of the Common Agricultural Policy (CAP) and the agri-environmental measures (EAFRD), support for diverse landscape elements, habitats and integrating ecological focus areas and buffer zones into farmland should be significantly increased.
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The regulation of pesticides in the European Union (EU) relies on a network of hard law (legislation and implementing acts) and soft law (non-legally binding guidance documents and administrative and scientific practices). Both hard and soft laws govern how risk assessments are conducted, but a significant role is left to the latter. Europe’s pesticide regulation is one of the most stringent in the world. Its stated objectives are to ensure an independent, objective and transparent assessment of pesticides and achieve a high level of protection for health and environment. However, a growing body of evidence shows that pesticides that have passed through this process and are authorised for use may harm humans, animals and the environment. The authors of the current paper – experts in toxicology, law and policy – identified shortcomings in the authorisation process, focusing on the EU assessment of the pesticide active substance glyphosate. The shortcomings mostly consist of failures to implement the hard or soft laws. But in some instances the law itself is responsible, as some provisions can only fail to achieve its objectives. Ways to improve the system are proposed, requiring changes in hard and soft laws as well as in administrative and scientific practices.
Chapter
We start to what turns out to be the most important aspect of both climate change and strain: the scientific findings that increasingly have demonstrated that undeniable connection. Part 1 addresses the role of forests and cultivated lands, while Part 2 deals with water and air issues. The starting point can be traced to the work of Aldo Leopold, a forester, who posited the foundation role played by forests, as he decries the habit of treating nature as property with no regard for the integrity of the Earth. His words have been echoed and further developed through the decades, as one scientist after the other noticed that agribusiness led to soil erosion, soil and water pollution and ecological deterioration. Unexpected support for this position comes also from Canadian/Ontario religious groups such as the Mennonites and Dutch Reformed people, who demand support for the Earth’s life-giving and life-supporting capacities, based on their faith’s obligation to God’s creation, as far back as the early 1990s. A similar position can be found today in the work of Pope Francis, in his impersonate defense of the integrity of the Earth. Finally the clearest explicit connection between climate change and what I have termed Hunger came with the explicit FAO Report of Olivier de Schutter. Respect for nature and its ways is also in ounce in the lifestyle and beliefs of Indigenous peoples, among the most affected by the war on the weakest and the poorest people. Part 2 turns to water, an absolute necessity of life, but exploited in too many ways, despite the sting legal regimes for its protection, be it in lakes, streams or oceans, the former polluted and often unable to support life within them, the latter clogged by the plastic that affects all marine life. Finally the air is also unsafe, unhealthy and so polluted that in some countries wearing masks for protection has become a way of life.
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There is a pressing need to identify the molecular mechanisms underlying the, often magnifying, interactive effects between contaminants and natural stressors. Here we test our hypothesis that lower general stress defence responses contribute to synergistic interactions between stressors. We focus on the widespread pattern that many contaminants are more toxic at higher temperatures. Specifically, we tested the effects of an environmentally realistic low‐effect and high‐effect concentration of the pesticide chlorpyrifos under warming at the gene expression level in the northern house mosquito Culex pipiens molestus (Forskal, 1775). By applying the independent action model for combined stressors on RNA‐sequencing data, we identified interactive gene expression patterns under combined exposure to chlorpyrifos and warming for general stress defence responses: protection of macromolecules, antioxidant processes, detoxification and energy metabolism/allocation. Most of these general stress defence response genes showed upregulated antagonistic interactions (i.e., were less upregulated than expected under the independent action model). This indicates that when pesticide exposure was combined with warming, the general stress defence responses were no longer buffering increased stress levels, which may contribute to a higher sensitivity to toxicants under warming. These upregulated antagonistic interactions were stronger for the high‐effect chlorpyrifos concentration, indicating that exposure to this concentration under warming was most stressful. Our results highlight that quantitative analysis of the frequency and strength of the interaction types of general stress defence response genes, specifically focusing on antagonistic upregulations and synergistic downregulations, may advance our understanding of how natural stressors modify the toxicity of contaminants.
Preprint
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Background. Microorganisms govern important ecosystems processes, in particular the degradation of organic matter (OM). However, microorganisms are rarely considered in efforts to monitor ecosystem health and functioning. Evidence suggests that environmental perturbations can adversely affect microbial communities and and their ability to use available substrates. However, whether impacted microbial efficiencies in extracting and utilizing the available resources (resource niche breadth) translate to changes in organic matter (OM) degradation in natural systems remains poorly understood. Methods. Here we evaluated effects of differences in organic matter (OM) related to agricultural land use (OM derived from ditches adjacent to grasslands, bulb fields and a pristine dune area) on microbial functioning. We specifically assessed 1) resource niche breadths of microbial communities during initial community assembly in laboratory microcosms and already established natural communities, and 2) how changes in community resource niche breadth translates to the degradation of natural OM. Results. A disparity existed between microbial resource niche breadth in laboratory incubations and natural microbial communities. Resource utilization and niche breadth of natural microbial communities was observed to be constrained in drainage ditches adjacent to agricultural fields. This outcome coincides with retarded degradation of natural OM collected from ditches adjacent to hyacinth bulb fields. Microbial communities in bulb field ditches further showed functional redundancy when offered grassland OM of seemingly higher substrate quality. Discussion. Results presented in this study suggest that agricultural practices can impose constraints on microbial functional diversity by reducing OM resource quality, which can subsequently translate to confined microbial resource niche differentiation and reduced organic matter degradation rates. This hints that assessments of actual microbial resource utilization and niche differentiation could potentially be used to assess the ecological health and functioning of natural communities.
Article
There is growing evidence that both increases in mean temperature and the widespread daily temperature fluctuations (DTF) may increase pesticide toxicity. Nevertheless, the likely more stressful, realistic combination of the two warming-related stressors has rarely been considered in ecotoxicology. Moreover, we have little knowledge on whether these stressor combinations could impair ecosystem functioning. We examined the effect of the pesticide chlorpyrifos under an increased mean temperature (+4 °C, from 18 °C to 22 °C) and in the presence of DTF (constant and 8 °C) on two life-history traits (mortality and growth rate) and one ecologically important behavioural trait (feeding rate) in the freshwater isopod Asellus aquaticus. The chlorpyrifos concentration used, 0.2 μg/L, did not cause mortality in any thermal condition, nor did it cause sublethal effects at the mean temperature of 18 °C. A key finding was that growth rate was strongly reduced by the pesticide only under the combination of both a higher mean temperature and DTF, highlighting the importance of testing toxicity under this realistic thermal scenario. The leaf consumption of chlorpyrifos-exposed isopods increased at the higher mean temperature when this was kept constant, however, it lowered again towards control levels when DTF was induced, thereby contributing to the growth reduction at this most stressful condition. These alterations of growth and leaf degradation rates may impact nutrient recycling, a key ecosystem function. Our results highlight the importance of integrating both increases in mean temperature and in DTF to improve current and future ecological risk assessment of pesticides.
Preprint
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Background. Microorganisms govern important ecosystems processes, in particular the degradation of organic matter (OM). However, microorganisms are rarely considered in efforts to monitor ecosystem health and functioning. Evidence suggests that environmental perturbations can adversely affect microbial communities and and their ability to use available substrates. However, whether impacted microbial efficiencies in extracting and utilizing the available resources (resource niche breadth) translate to changes in organic matter (OM) degradation in natural systems remains poorly understood. Methods. Here we evaluated effects of differences in organic matter (OM) related to agricultural land use (OM derived from ditches adjacent to grasslands, bulb fields and a pristine dune area) on microbial functioning. We specifically assessed 1) resource niche breadths of microbial communities during initial community assembly in laboratory microcosms and already established natural communities, and 2) how changes in community resource niche breadth translates to the degradation of natural OM. Results. A disparity existed between microbial resource niche breadth in laboratory incubations and natural microbial communities. Resource utilization and niche breadth of natural microbial communities was observed to be constrained in drainage ditches adjacent to agricultural fields. This outcome coincides with retarded degradation of natural OM collected from ditches adjacent to hyacinth bulb fields. Microbial communities in bulb field ditches further showed functional redundancy when offered grassland OM of seemingly higher substrate quality. Discussion. Results presented in this study suggest that agricultural practices can impose constraints on microbial functional diversity by reducing OM resource quality, which can subsequently translate to confined microbial resource niche differentiation and reduced organic matter degradation rates. This hints that assessments of actual microbial resource utilization and niche differentiation could potentially be used to assess the ecological health and functioning of natural communities.
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Widespread use of insecticides to control arthropod pests of agricultural, veterinary, and medical importance imposes selection for resistance to these chemicals. Resistance is an evolutionary adaptation conferred by genes encoding modified receptor proteins or enzymes that detoxify insecticides. Advances in insect biochemistry and genomics are casting light on underlying resistance mutations and mechanisms, and providing sophisticated tools for diagnosing changes in susceptibility over time and space. Strategies for combating resistance, based on knowledge of pest population genetics and ecology, are increasingly being used to prolong the effective lifespan both of conventional insecticides and of toxins genetically engineered into crop plants.
Technical Report
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EFSA’s Panel on Plant Protection Products and their Residues (PPR) was tasked to revise the Guidance Document (GD) on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev.4 (final), 17 October 2002). This Guidance of the PPR Panel is the first of three requested deliverables within this mandate. It has its focus on tiered acute and chronic effect assessment schemes with detailed guidance on tier 1 and higher tier effect assessments for aquatic organisms in edge-of-field surface waters and on proposals regarding how to link effects to exposure estimates. The exposure assessment methodology was not reviewed and it is assumed that the current FOCUS surface water exposure assessment methodology will continue to be used for exposure assessment at EU level. The current GD is intended to be used for authorisation of active substances at EU level as well as for plant protection products at Member State level. The effect assessment schemes in this GD allow for the derivation of regulatory acceptable concentrations (RACs) on the basis of two options: (1) the ecological threshold option (ETO), accepting negligible population effects only, and (2) the ecological recovery option (ERO), accepting some population-level effects if ecological recovery takes place within an acceptable time period. In the tiered effect assessment schemes, in principle, all tiers (1, 2 and 3) are able to address the ETO, while the model ecosystem approach (tier 3), under certain conditions, is able to also address the ERO. The GD provides the scientific background for the risk assessment to aquatic organisms in edge-of-field surface waters and is structured to give detailed guidance on all assessment steps. An executive summary joining all parts of the guidance and decision schemes in a concise way is provided and is intended to help applicants and regulatory authorities in day-to-day use.
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General protection goals for the environmental risk assessment (ERA) of plant protection products are stated in European legislation but specific protection goals (SPGs) are often not precisely defined. These are however crucial for designing appropriate risk assessment schemes. The process followed by the Panel on Plant Protection Products and their Residues (PPR) of the European Food Safety Authority (EFSA) as well as examples of resulting SPGs obtained so far for environmental risk assessment (ERA) of pesticides is presented. The ecosystem services approach was used as an overarching concept for the development of SPGs, which will likely facilitate communication with stakeholders in general and risk managers in particular. It is proposed to develop SPG options for 7 key drivers for ecosystem services (microbes, algae, non target plants (aquatic and terrestrial), aquatic invertebrates, terrestrial non target arthropods including honeybees, terrestrial non-arthropod invertebrates, and vertebrates), covering the ecosystem services that could potentially be affected by the use of pesticides. These SPGs need to be defined in 6 dimensions: biological entity, attribute, magnitude, temporal and geographical scale of the effect, and the degree of certainty that the specified level of effect will not be exceeded. In general, to ensure ecosystem services, taxa representative for the key drivers identified need to be protected at the population level. However, for some vertebrates and species that have a protection status in legislation, protection may be at the individual level. To protect the provisioning and supporting services provided by microbes it may be sufficient to protect them at the functional group level. To protect biodiversity impacts need to be assessed at least at the scale of the watershed/ landscape.
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Compared with nutrient levels and habitat degradation, the importance of agricultural pesticides in surface water may have been underestimated due to a lack of comprehensive quantitative analysis. Increasing pesticide contamination results in decreasing regional aquatic biodiversity, i.e., macroinvertebrate family richness is reduced by ∼30% at pesticide concentrations equaling the legally accepted regulatory threshold levels (RTLs). This study provides a comprehensive metaanalysis of 838 peer-reviewed studies (>2,500 sites in 73 countries) that evaluates, for the first time to our knowledge on a global scale, the exposure of surface waters to particularly toxic agricultural insecticides. We tested whether measured insecticide concentrations (MICs; i.e., quantified insecticide concentrations) exceed their RTLs and how risks depend on insecticide development over time and stringency of environmental regulation. Our analysis reveals that MICs occur rarely (i.e., an estimated 97.4% of analyses conducted found no MICs) and there is a complete lack of scientific monitoring data for ∼90% of global cropland. Most importantly, of the 11,300 MICs, 52.4% (5,915 cases; 68.5% of the sites) exceeded the RTL for either surface water (RTLSW) or sediments. Thus, the biological integrity of global water resources is at a substantial risk. RTLSW exceedances depend on the catchment size, sampling regime, and sampling date; are significantly higher for newer-generation insecticides (i.e., pyrethroids); and are high even in countries with stringent environmental regulations. These results suggest the need for worldwide improvements to current pesticide regulations and agricultural pesticide application practices and for intensified research efforts on the presence and effects of pesticides under real-world conditions.
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Large-scale use of the persistent and potent neonicotinoid and fipronil insecticides has raised concerns about risks to ecosystem functions provided by a wide range of species and environments affected by these insecticides. The concept of ecosystem services is widely used in decision making in the context of valuing the service potentials, benefits, and use values that well-functioning ecosystems provide to humans and the biosphere and, as an endpoint (value to be protected), in ecological risk assessment of chemicals. Neonicotinoid insecticides are frequently detected in soil and water and are also found in air, as dust particles during sowing of crops and aerosols during spraying. These environmental media provide essential resources to support biodiversity, but are known to be threatened by long-term or repeated contamination by neonicotinoids and fipronil. We review the state of knowledge regarding the potential impacts of these insecticides on ecosystem functioning and services provided by terrestrial and aquatic ecosystems including soil and freshwater functions, fisheries, biological pest control, and pollination services. Empirical studies examining the specific impacts of neonicotinoids and fipronil to ecosystem services have focused largely on the negative impacts to beneficial insect species (honeybees) and the impact on pollination service of food crops. However, here we document broader evidence of the effects on ecosystem functions regulating soil and water quality, pest control, pollination, ecosystem resilience, and community diversity. In particular, microbes, invertebrates, and fish play critical roles as decomposers, pollinators, consumers, and predators, which collectively maintain healthy communities and ecosystem integrity. Several examples in this review demonstrate evidence of the negative impacts of systemic insecticides on decomposition, nutrient cycling, soil respiration, and invertebrate populations valued by humans. Invertebrates, particularly earthworms that are important for soil processes, wild and domestic insect pollinators which are important for plant and crop production, and several freshwater taxa which are involved in aquatic nutrient cycling, were all found to be highly susceptible to lethal and sublethal effects of neonicotinoids and/or fipronil at environmentally relevant concentrations. By contrast, most microbes and fish do not appear to be as sensitive under normal exposure scenarios, though the effects on fish may be important in certain realms such as combined fish-rice farming systems and through food chain effects. We highlight the economic and cultural concerns around agriculture and aquaculture production and the role these insecticides may have in threatening food security. Overall, we recommend improved sustainable agricultural practices that restrict systemic insecticide use to maintain and support several ecosystem services that humans fundamentally depend on.
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In December 2013, the European Union (EU) enacted the reformed Common Agricultural Policy (CAP) for 2014–2020, allocating almost 40% of the EU's budget and influencing management of half of its terrestrial area. Many EU politicians are announcing the new CAP as “greener,” but the new environmental prescriptions are so diluted that they are unlikely to benefit biodiversity. Individual Member States (MSs), however, can still use flexibility granted by the new CAP to design national plans to protect farmland habitats and species and to ensure long-term provision of ecosystem services.
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The first book in two decades to address this multi-faceted field, The Toxicology and Biochemistry of Insecticides provides the most up-to-date information on insecticide classification, formulation, mode of action, resistance, metabolism, environmental fate, and regulatory legislation. The book draws on the author's groundbreaking research in insect detoxification. It discusses mechanisms at the molecular level such as specific enzymes that contribute to insecticide resistance, the modification of which can change insecticide susceptibility and influence host plant selections in phytophagous insects. Beginning with a general introduction, eleven chapters integrate classical toxicology with physiology, biochemistry, and molecular biology to present a comprehensive look at the field. The book discusses the demand and formulation of pesticides and describes each type from dusts and powders to baits and aerosols. It classifies insecticides by target, chemical compound, and mechanism; evaluates toxicity testing procedures; explains pesticide uptake, mode of action, and metabolism; and explores species differences, resistance, and interactions. It also considers pesticides in the environment and federal and state regulatory legislation and enforcement. A long-awaited, state-of-the-science review on insect toxicology, this indispensable book brings you up-to-date on the many aspects and implications of pesticide use and provides the necessary background and platform from which to conduct future research.
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The paper assesses the usefulness of the concept of ‘concentration addition’ (CA) for describing the joint effect of pesticides on aquatic organisms, based on literature data from 1972 to 1998. For more than 90% of 202 mixtures in 26 studies, CA was found to predict effect concentrations correctly within a factor of two. Although from a theoretical point of view the assumption of CA may be invalid when dealing with mixtures of compounds with dissimilar modes of action, the experimental results have usually been indistinguishable from that predicted by CA. Deviations from CA did occur, but were mostly limited in extent. Upward and downward deviations from CA were of comparable magnitude and frequency, and tended to cancel each other out. The combinations identified as most frequently leading to deviations from CA were those of an organophosphorus ester or a carbamate with either another organophosphorus ester or a synthetic pyrethroid.© 2000 Society of Chemical Industry
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Organic chemicals can contribute to local and regional losses of freshwater biodiversity and ecosystem services. However, their overall relevance regarding larger spatial scales remains unknown. Here, we present, to our knowledge, the first risk assessment of organic chemicals on the continental scale comprising 4,000 European monitoring sites. Organic chemicals were likely to exert acute lethal and chronic long-term effects on sensitive fish, invertebrate, or algae species in 14% and 42% of the sites, respectively. Of the 223 chemicals monitored, pesticides, tributyltin, polycyclic aromatic hydrocarbons, and brominated flame retardants were the major contributors to the chemical risk. Their presence was related to agricultural and urban areas in the upstream catchment. The risk of potential acute lethal and chronic long-term effects increased with the number of ecotoxicologically relevant chemicals analyzed at each site. As most monitoring programs considered in this study only included a subset of these chemicals, our assessment likely underestimates the actual risk. Increasing chemical risk was associated with deterioration in the quality status of fish and invertebrate communities. Our results clearly indicate that chemical pollution is a large-scale environmental problem and requires far-reaching, holistic mitigation measures to preserve and restore ecosystem health.
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A comprehensive assessment of pesticides in surface waters is challenging due to the large number of potential contaminants. Most scientific studies and routine monitoring programs include only 15-40 pesticides, which leads to error-prone interpretations. In the present study, an extensive analytical screening was carried out using liquid chromatography-high-resolution mass spectrometry, covering 86% of all polar organic pesticides sold in Switzerland and applied to agricultural or urban land (in total 249 compounds), plus 134 transformation products; each of which could be quantified in the low ng/L range. Five medium-sized rivers, containing large areas of diverse crops and urban settlements within the respective catchments, were sampled between March and July 2012. More than 100 parent compounds and 40 transformation products were detected in total, between 30 and 50 parent compounds in each two-week composite sample in concentrations up to 1500 ng/L. The sum of pesticide concentrations was above 1000 ng/L in 78% of samples. The chronic environmental quality standard was exceeded for 19 single substances; using a mixture toxicity approach, exceedances occurred over the whole measurement period in all rivers. With scenario calculations including only 30-40 frequently measured pesticides, the number of detected substances and the mixture toxicity would be underestimated on average by a factor of 2. Thus, selecting a subset of substances to assess the surface water quality may be sufficient, but a comprehensive screening yields substantially more confidence.