Developing climatic scenarios for pesticide fate modelling in Europe

Development of surface water exposure scenarios for risk assessment of pesticides in Korea

Surface water exposure scenarios used in the risk assessment of Korea's aquatic ecosystems, were developed to represent the 90th percentile pesticide exposure situation as a part of the country's pesticide registration procedure. The scenarios are used to estimate the pesticide concentration in the water of a rice paddy and small streams for three protection goals: (i) mudfish in rice paddies, (ii) the aquatic ecosystem of small streams located near rice paddies, and (iii) the aquatic ecosystem of small streams located near fruit orchards. The scenarios were derived taking into account major exposure routes, such as spray drift, runoff, and drainage. The scenarios were parameterized for appropriate models including the pesticide root zone model (PRZM) and the toxic substances in surface waters model (TOXSWA). A total of 17 pesticide compounds and 28 formulated products were selected to test the risk assessment using the developed scenarios. The simulated predicted environmental concentrations (PECs) fully reflected a) the exposure routes for each protection goal b) the use patterns of the products c) physicochemical properties of the pesticides, and d) meteorological conditions of Korea. However, while assessing the risks for aquatic organisms we observed that for most of the selected pesticides the calculated exposure concentrations were higher than the regulatory acceptable concentration (RAC). To implement the exposure scenarios and models for pesticide authorization in Korea, further research on the RACs is needed. We also recommend studies to develop a higher-tier model and risk-mitigation measures that can be applied to the Korean situation.

Assessment of new low input vine systems: Dataset on environmental, soil, biodiversity, growth, yield, disease incidence, juice and wine quality, cost and social data

This article describes the environmental, agronomical, economical and social indicators characterization of eleven new low input vine systems to explore their multicriteria performances. These data also describe the reproducibility of all the indicators over six harvest years (2013-2018) over eleven selected winegrower plots. The environmental characterizations are total treatment frequency index, fungicide treatment frequency index, I-Phy indicator from Indigo® method, copper rate, soil compaction, bacterial activity in soil, bacterial molecular biomass, potential nitrogen mineralization rate, amont of avalaible nitrogen in soil at veraison, total specific floristic richness, and relative pollination value. The agronomical characterizations are vine phenology, vine vigour, plot yield, powdery mildew intensity on bunches at harvest, grey rot intensity on bunches at harvest, juice sugar rate (total soluble solids) and juice total acidity rate (titrable acidity) at harvest, wine characteristics after microvinification. The economical characterizations are brut semi-margin at the plot and at the farm scale. The sociological characterizations are human capital, penibility, hardouness work and pesticide risk.

Sensitivity analysis of the Pesticide in Water Calculator model for applications in the Pampa region of Argentina

Despite the widespread use of pesticides in the Pampa region of Argentina, mathematical models are rarely employed to predict pesticide fate due to the lack of regionally tested models and the absence of readily available databases to run such models. The objective of the current study was to perform a sensitivity analysis of the Pesticide in Water Calculator (PWC) model for the Pampa Region of Argentina. The sensitivity analysis was performed while simulating applications of 2,4-D (mobile, low Kd) and glyphosate (soil-binding, high Kd) in five localities of the Pampa region: Anguil, Paraná, Marcos Juárez, Pergamino and Tres Arroyos. The sensitivity of the various parameters involved in PWC modelling was evaluated though a two-steps sensitivity analysis which included a first screening of less sensitive parameters with Morris method, followed by a fully global sensitivity analysis of the remaining parameters using Sobol method. When ran under soil and climate conditions typical of the Pampa region of Argentina, PWC was most sensitive to 25% of the parameters evaluated. The sensitive parameters identified depended mainly on the nature of the pesticide molecule being modelled; the location and endpoint considered having much less influence on the sensitivity results. Sensitive parameters belonged to two main grand categories: (i) degradation rates of the pesticide in soil and water, and (ii) parameters descriptive of soil binding, runoff and erosion. The sensitivity analysis of the model PWC performed in the current study represents a crucial first step towards the development and expansion of probabilistic pesticide risk assessment in Argentina, and provides important parameterization criteria that will help obtaining more certain modelling results from PWC in Argentina and elsewhere.

Conceptual considerations on exposure assessment goals for aquatic pesticide risks at EU level

Assessment of the risk to aquatic organisms is an important aspect of pesticide registration. This assessment must be based on well-defined exposure assessment goals (EAGs). However, these goals have not yet been defined for the EU authorization procedure. The definition of an aquatic EAG has seven elements, including: type of water body, spatial dimension of this body, spatial population of water bodies, multi-year temporal population of concentrations for a single water body, and the space-time percentile combination to be selected from the spatio-temporal population of concentrations. The seven elements are split into 16 items, three which are within the risk-management domain. The remaining 13 scientific items should preferably be based on consistency with landscape-level approaches. Subdivision of the spatial population of water bodies on the occurrence of exposure routes should be avoided (although this is current practice). The multi-year temporal population of concentrations should be based on all years in rotational crops (including years without applications). Risk managers should be offered a suite of coherent packages of EAGs and effect assessment goals from which they can select the package corresponding to the desired overall level of protection. © 2017 Society of Chemical Industry.

Evaluation of FOCUS surface water pesticide concentration predictions and risk assessment of field-measured pesticide mixtures-a crop-based approach under Mediterranean conditions

FOCUS models are used in the European regulatory risk assessment (RA) to predict individual pesticide concentrations in edge-of-field surface waters. The scenarios used in higher tier FOCUS simulations were mainly based on Central/North European, and work is needed to underpin the validity of simulated exposure profiles for Mediterranean agroecosystems. In addition, the RA of chemicals are traditionally evaluated on the basis of single substances although freshwater life is generally exposed to a multitude of pesticides. In the present study, we monitored 19 pesticides in surface waters of five locations in the Portuguese 'Lezíria do Tejo' agricultural area. FOCUS step 3 simulations were performed for the South European scenarios to estimate predicted environmental concentrations (PECs). We verified that 44% of the PECs underestimated the measured environmental concentrations (MEC) of the pesticides, showing a non-compliance with the field data. Risk was assessed by comparing the environmental quality standards (EQS) and regulatory acceptable concentrations with their respective MECs. Risk of mixtures was demonstrated in 100% of the samples with insecticides accounting for 60% of the total risk identified. The overall link between the RA and the actual situation in the field must be considerably strengthened, and field studies on pesticide exposure and effects should be carried out to assist the improvement of predictive approaches used for regulatory purposes.

Pesticide exposure assessment for surface waters in the EU. Part 2: Determination of statistically based run-off and drainage scenarios for Germany

BACKGROUND

In order to assess surface water exposure to active substances of plant protection products (PPPs) in the European Union (EU), the FOCUS (FOrum for the Co-ordination of pesticide fate models and their USe) surface water workgroup introduced four run-off and six drainage scenarios for Step 3 of the tiered FOCUSsw approach. These scenarios may not necessarily represent realistic worst-case situations for the different Member States of the EU. Hence, the suitability of the scenarios for risk assessment in the national authorisation procedures is not known.

RESULTS

Using Germany as an example, the paper illustrates how national soil-climate scenarios can be developed to model entries of active substances into surface waters from run-off and erosion (using the model PRZM) and from drainage (using the model MACRO). In the authorisation procedure for PPPs on Member State level, such soil-climate scenarios can be used to determine exposure endpoints with a defined overall percentile.

CONCLUSION

The approach allows the development of national specific soil-climate scenarios and to calculate percentile-based exposure endpoints. The scenarios have been integrated into a software tool analogous to FOCUS-SWASH which can be used in the future to assess surface water exposure in authorisation procedures of PPPs in Germany. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Carbaryl toxicity prediction to soil organisms under high and low temperature regimes

Many studies on risk assessment of pesticides on non-target organisms have been performed based on standardized protocols that reflect conditions in temperate climates. However, the responses of organisms to chemical compounds may differ according to latitude and thus predicting the toxicity of chemicals at different temperatures is an important factor to consider in risk assessment. The toxic effects of the pesticide carbaryl were evaluated at different temperature regimes, which are indicative of temperate and tropical climates and are relevant to climate change predictions or seasonal temperature fluctuations. Four standard organisms were used (Folsomia candida, Eisenia andrei; Triticum aestivum and Brassica rapa) and the effects were assessed using synergistic ratios, calculated from EC/LC50 values. When possible, the MIXTOX tool was used based on the reference model of independent action (IA) and possible deviations. A decrease on carbaryl toxicity at higher temperatures was found in F. candida reproduction, but when the mixtox tool was used no interactions between these stressors (Independent Action) was observed, so an additive response was suggested. Synergistic ratios showed a tendency to synergism at high temperatures for E. andrei and B. rapa and antagonism at low temperatures for both species. T. aestivum showed to be less affected than expected (antagonism), when exposed to both low and high temperatures. The results showed that temperature may increase the deleterious effects of carbaryl to non-target organisms, which is important considering both seasonal and latitude related differences, as well as the global climate change context.

Surface water risk assessment of pesticides in Ethiopia

Scenarios for future use in the pesticide registration procedure in Ethiopia were designed for 3 separate Ethiopian locations, which are aimed to be protective for the whole of Ethiopia. The scenarios estimate concentrations in surface water resulting from agricultural use of pesticides for a small stream and for two types of small ponds. Seven selected pesticides were selected since they were estimated to bear the highest risk to humans on the basis of volume of use, application rate and acute and chronic human toxicity, assuming exposure as a result of the consumption of surface water. Potential ecotoxicological risks were not considered as a selection criterion at this stage. Estimates of exposure concentrations in surface water were established using modelling software also applied in the EU registration procedure (PRZM and TOXSWA). Input variables included physico-chemical properties, and data such as crop calendars, irrigation schedules, meteorological information and detailed application data which were specifically tailored to the Ethiopian situation. The results indicate that for all the pesticides investigated the acute human risk resulting from the consumption of surface water is low to negligible, whereas agricultural use of chlorothalonil, deltamethrin, endosulfan and malathion in some crops may result in medium to high risk to aquatic species. The predicted environmental concentration estimates are based on procedures similar to procedures used at the EU level and in the USA. Addition of aquatic macrophytes as an ecotoxicological endpoint may constitute a welcome future addition to the risk assessment procedure. Implementation of the methods used for risk characterization constitutes a good step forward in the pesticide registration procedure in Ethiopia.

Regulatory FOCUS surface water models fail to predict insecticide concentrations in the field

The FOrum for the Co-ordination of pesticide fate models and their USe (FOCUS) exposure models are used to predict the frequency and magnitude of pesticide surface water concentrations within the European regulatory risk assessment. The predictions are based on realistic worst-case assumptions that result in predicted environmental concentrations (PEC). Here, we compared for the first time a larger data set of 122 measured field concentrations (MFC) of agricultural insecticides extracted from 22 field studies to respective PECs by using FOCUS steps 1-4. While FOCUS step 1 and 2 PECs generally overpredicted the MFCs, 23% of step 3 and 31% of step 4 standard PECs were exceeded by surface water MFCs, which questions the protectiveness of the FOCUS exposure assessment. Using realistic input parameters, step 3 simulations underpredicted MFCs in surface water and sediment by 43% and 78%, respectively, which indicate that a higher degree of realism even reduces the protectiveness of model results. The ratios between PEC and MFC in surface water were significantly lower for pyrethroids than for organophosphorus or organochlorine insecticides, which suggests that the FOCUS predictions are less protective for hydrophobic insecticides. In conclusion, the FOCUS modeling approach is not protective for insecticide concentrations in the field.