Meta-modeling methods for estimating ammonia volatilization from nitrogen fertilizer and manure applications.

Accurate estimations of ammonia (NH3) emissions due to nitrogen (N) fertilization are required to identify efficient mitigation techniques and improve agricultural practices. Process-based models such as Volt'Air can be used for this purpose because they incorporate the effects of several key factors influencing NH3 volatilization at fine spatio-temporal resolutions. However, these models require a large number of input variables and their implementation on a large scale requires long computation times that may restrict their use by public environmental agencies. In this study, we assess the capabilities of various types of meta-models to emulate the complex process-based Volt'Air for estimating NH3 emission rates from N fertilizer and manure applications. Meta-models were developed for three types of fertilizer (N solution, cattle farmyard manure, and pig slurry) for four major agricultural French regions (Bretagne, Champagne-Ardenne, Ile-de-France, and Rhône-Alpes) and at the national (France) scale. The meta-models were developed from 106,092 NH3 emissions simulated by Volt'Air in France. Their performances were evaluated by cross-validation, and the meta-models providing the best approximation of the original model were selected. The results showed that random forest and ordinary linear regression models were more accurate than generalized additive models, partial least squares regressions, and least absolute shrinkage and selection operator regressions. Better approximations of Volt'Air simulations were obtained for cattle farmyard manure (3% < relative root mean square error of prediction (RRMSEP) < 8%) than for pig slurry (17% < RRMSEP < 19%) and N solution (21% < RRMSEP < 40%). The selected meta-models included between 6 and 15 input variables related to weather conditions, soil properties and cultural practices. Because of their simplicity and their short computation time, our meta-models offer a promising alternative to process-based models for NH3 emission inventories at both regional and national scales. Our approach could be implemented to emulate other process-based models in other countries.

Prediction of the Fate of Organic Compounds in the Environment From Their Molecular Properties: A Review.

A comprehensive review of quantitative structure-activity relationships (QSAR) allowing the prediction of the fate of organic compounds in the environment from their molecular properties was done. The considered processes were water dissolution, dissociation, volatilization, retention on soils and sediments (mainly adsorption and desorption), degradation (biotic and abiotic), and absorption by plants. A total of 790 equations involving 686 structural molecular descriptors are reported to estimate 90 environmental parameters related to these processes. A significant number of equations was found for dissociation process (pKa), water dissolution or hydrophobic behavior (especially through the KOW parameter), adsorption to soils and biodegradation. A lack of QSAR was observed to estimate desorption or potential of transfer to water. Among the 686 molecular descriptors, five were found to be dominant in the 790 collected equations and the most generic ones: four quantum-chemical descriptors, the energy of the highest occupied molecular orbital (EHOMO) and the energy of the lowest unoccupied molecular orbital (ELUMO), polarizability (α) and dipole moment (µ), and one constitutional descriptor, the molecular weight. Keeping in mind that the combination of descriptors belonging to different categories (constitutional, topological, quantum-chemical) led to improve QSAR performances, these descriptors should be considered for the development of new QSAR, for further predictions of environmental parameters. This review also allows finding of the relevant QSAR equations to predict the fate of a wide diversity of compounds in the environment.

Measuring Leaf Penetration and Volatilization of Chlorothalonil and Epoxiconazole Applied on Wheat Leaves in a Laboratory-Scale Experiment.

Estimation of pesticide volatilization from plants is difficult because of our poor understanding of foliar penetration by pesticides, which governs the amount of pesticide available for volatilization from the leaf surface. The description of foliar penetration is still incomplete because experimental measurements of this complex process are difficult. In this study, the dynamics of leaf penetration of C-chlorothalonil and C-epoxiconazole applied to wheat leaves were measured in a volatilization chamber, which allowed us to simultaneously measure pesticide volatilization. Fungicide penetration into leaves was characterized using a well-defined sequential extraction procedure distinguishing pesticide fractions residing at different foliar compartments; this enabled us to accurately measure the penetration rate constant into the leaves. The effect of pesticide formulation was also examined by comparing formulated and pure epoxiconazole. We observed a strong effect of formulation on leaf penetration in the case of a systemic product. Furthermore, the penetration rate constant of formulated epoxiconazole was almost three times that of pure epoxiconazole (0.47 ± 0.20 and 0.17 ± 0.07, respectively). Our experimental results showed high recovery rates of the radioactivity applied within the range of 90.5 to 105.2%. Moreover, our results confirm that pesticide physicochemical properties are key factors in understanding leaf penetration of pesticide and its volatilization. This study provides important and useful parameters for mechanistic models describing volatilization of fungicides applied to plants, which are scarce in the literature.

Modeling pesticide volatilization: testing the additional effect of gaseous adsorption on soil solid surfaces.

Pesticide volatilization from bare soil exhibits usually a diurnal cycle with a potentially large decrease when the soil surface dries. We assume here that this decrease may be due to the increase in adsorption of gaseous pesticides to soil under dry conditions. Thus, a precise description of the change with time of water content of the soil surface and of additional process such as gaseous adsorption is required. We used the Volt'Air model: we first extended the van Genuchten curve to drier conditions and then inserted a partitioning coefficient of the pesticide between the air-filled pore space and the soil constituents. This coefficient was calculated by a quantum-chemistry-based method with a dependence on the Specific Surface Area of the soil (SSA) and Relative Humidity (RH) of the air-filled pore space. These developments were assessed by comparing with two data sets on volatilization of trifluralin applied to bare soil. The updated Volt'Air model allowed a better description of the volatilization dynamics on a diurnal cycle (increasing efficiency factor from 0.85 to 0.96 and -2.73 to 0.17 and decreasing RMSE from 146 to 78 and 353 to 168 for both scenarios) as well as the effect of a rewetting situation. Recommendations are made for further refining the description of this process together with the soil water conditions.

Characterizing environmental contamination by plant protection products along the land-to-sea continuum:a focus on France and French overseas territories.

Environmental compartments are contaminated by a broad spectrum of plant protection products (PPPs) that are currently widely used in agriculture or, for some of them, whose use was banned many years ago. The aim of this study is to draw up an overview of the levels of contamination of soils, continental aquatic environments, seawaters and atmosphere by organic PPPs in France and the French overseas territories, based on data from the scientific publications and the grey literature. It is difficult to establish an exhaustive picture of the overall contamination of the environment because the various compartments monitored, the monitoring frequencies, the duration of the studies and the lists of substances are not the same. Of the 33 PPPs most often recorded at high concentration levels in at least one compartment, 5 are insecticides, 9 are fungicides, 15 are herbicides and 4 are transformation products. The PPP contamination of the environment shows generally a seasonal variation according to crop cycles. On a pluriannual scale, the contamination trends are linked to the level of use driven by the pest pressure, and especially to the ban of PPP. Overall, the quality of the data acquired has been improved thanks to new, more integrative sampling strategies and broad-spectrum analysis methods that make it possible to incorporate the search for emerging contaminants such as PPP transformation products. Taking into account additional information (such as the quantities applied, agricultural practices, meteorological conditions, the properties of PPPs and environmental conditions) combined with modelling tools will make it possible to better assess and understand the fate and transport of PPPs in the environment, inter-compartment transfers and to identify their potential impacts. Simultaneous monitoring of all environmental compartments as well as biota in selected and limited relevant areas would also help in this assessment.

Spray drift in viticulture: A dataset to analyse the influence of spray application techniques, hedges and their combination on the reduction of sedimentary drift, aerial drift and exposure of bystanders.

In 2021 and 2022, the national and cross-sector project CAPRIV funded by the French Ministry of Agriculture, made it possible to assess the influence of application techniques associated or not with a hedge or an anti-drift net on spray drift and bystander exposure. The acronym CAPRIV stands for "Concilier l'application des PPP et la protection des riverains" (Reconciling the use of PPPs and the protection of residents), within the orchard, viticulture, and field crops sectors. This specific data article focuses on viticulture. In viticulture, over the two years, 10 different spray application techniques were tested. For 3 of them the influence of a hedge on drift mitigation was also evaluated. All the trials were conducted on the "EoleDrift" test bench, with an artificial vegetation and an artificial wind. Spray drift has been measured according to a common protocol harmonised between cropping sectors within the project using three different types of passive drift collectors that were set up downwind of the treated field. Petri dishes collected sedimentary drift, PVC wires collected airborne drift and cotton T-shirts placed on manikins were used to assess potential dermal exposure of bystanders. The plant protection mix was simulated by a dilution of a fluorescent dye in water. The collected mass of dye was measured using a classical technique with dilution and concentration evaluation. Two fluorescent dyes were successively used, Brillant Sulfaflavine and Sulforhodamine B. A total amount of 4770 collectors were analysed individually. The data set provides a drift index for each collector expressed as the quantity of dye recovered per unit area of collector on the quantity of dye applied per unit area on the sprayed field multiplied by 100.

Spray drift in field crops: A dataset to analyse the influence of air induction nozzles, hedges, and their combination on the reduction of sedimentary drift, aerial drift and exposure of bystanders.

In 2021 and 2022, the national and cross-sector project CAPRIV funded by the French Ministry of Agriculture, made it possible to assess the influence of application techniques associated or not with a hedge or an anti-drift net on spray drift and bystander exposure. The acronym CAPRIV stands for "Concilier l'application des PPP et la protection des riverains" (Reconciling the use of PPPs and the protection of residents), within the orchard, viticulture, and field crops sectors. This specific data article focuses on field crops, especially on wheat. Over the two years, one boom sprayer equipped with flat fan and air induction nozzles was used on wheat fields adjacent to a hedgerow (2022) or not (2021). Spray drift has been measured according to a common protocol harmonised between cropping sectors within the project. Three different types of passive drift collectors were set up downwind of the treated field: Petri dishes for sedimentary drift, PVC wires placed between two masts for airborne drift and cotton T-shirts placed on manikins to assess potential dermal exposure of bystanders. The sprayed mix contained a fluorescent dye diluted in water. The mass of dye was measured using a classical technique with dilution and concentration evaluation. Two fluorescent dyes were successively used, Brillant Sulfaflavine and Sulforhodamine B. A total amount of 3792 collectors were analyzed individually. The data set provides a drift index for each collector expressed as the quantity of dye recovered per unit area of collector on the quantity of dye applied per unit area on the sprayed field multiplied by 100.

A conceptual framework for landscape-based environmental risk assessment (ERA) of pesticides.

While pesticide use is subject to strict regulatory oversight worldwide, it remains a main concern for environmental protection, including biodiversity conservation. This is partly due to the current regulatory approach that relies on separate assessments for each single pesticide, crop use, and non-target organism group at local scales. Such assessments tend to overlook the combined effects of overall pesticide usage at larger spatial scales. Integrative landscape-based approaches are emerging, enabling the consideration of agricultural management, the environmental characteristics, and the combined effects of pesticides applied in a same or in different crops within an area. These developments offer the opportunity to deliver informative risk predictions relevant for different decision contexts including their connection to larger spatial scales and to combine environmental risks of pesticides, with those from other environmental stressors. We discuss the needs, challenges, opportunities and available tools for implementing landscape-based approaches for prospective and retrospective pesticide Environmental Risk Assessments (ERA). A set of "building blocks" that emerged from the discussions have been integrated into a conceptual framework. The framework includes elements to facilitate its implementation, in particular: flexibility to address the needs of relevant users and stakeholders; means to address the inherent complexity of environmental systems; connections to make use of and integrate data derived from monitoring programs; and options for validation and approaches to facilitate future use in a regulatory context. The conceptual model can be applied to existing ERA methodologies, facilitating its comparability, and highlighting interoperability drivers at landscape level. The benefits of landscape-based pesticide ERA extend beyond regulation. Linking and validating risk predictions with relevant environmental impacts under a solid science-based approach will support the setting of protection goals and the formulation of sustainable agricultural strategies. Moreover, landscape ERA offers a communication tool on realistic pesticide impacts in a multistressors environment for stakeholders and citizens.

Gaseous deposition contributes to the contamination of surface waters by pesticides close to treated fields. A process-based model study.

The contribution of atmospheric pathways to surface waters contamination by pesticides has been demonstrated. At the local scale, modeling approaches as well as measurements show situations where the contribution of gaseous dry deposition is of the same order or even higher than the drift contribution. The approach presented here consists in estimating the gaseous emissions of pesticides applied in the field, their atmospheric dispersion, and finally their gaseous deposition into aquatic ecosystems at the local scale by running process-based models, that is, the one-dimensional model for pesticide volatilization following application on bare soil (Volt'Air) and the local-scale dispersion and deposition model (FIDES-2D), adapted for pesticides. A significant number of scenarios describes contrasted situations in terms of pedoclimatic conditions (covering 9 years of meteorological data), periods of pesticide application per year, physicochemical properties of the pesticides, and spatial configurations. The identification of the main factors governing gaseous deposition led to the definition of an effective emission factor which explains a large part of the deposition variability. Based on the model outputs, deposition curves are proposed, as a base for a new tool to assess the contribution of gaseous deposition to nontarget ecosystem contamination.

An indicator to assess risks on water and air of pesticide spraying in crop fields.

Stakeholders involved in actions to reduce the use and the impacts on the environment or human health of pesticides need operational tools to assess crop protection strategies in regard to these impacts. I-Phy3 brings together all improvements introduced since the first version of the indicator to better meet user's needs and requirements of integrating processes. I-Phy3 was deeply modified to ensure its predictive quality. I-Phy 3 is structured in three levels of aggregation in form of hierarchical fuzzy decision trees designed with the CONTRA method. At the 1st level, five basic subindicators assess the risk of contamination (RC) for the different transfer pathways involved in surface water, ground water and atmosphere contamination: leaching, runoff, drainage, drift, volatilization. At the 2nd level, RC subindicators are aggregated with a toxicity variable (human or aquatic) in a risk indicator. At the 3rd level, the global indicator I-Phy3 results from the aggregation of three risk indicators for groundwater, surface waters and air. I-Phy3 yielded better validation results than its previous versions. This effort to assess the predictive quality of the indicator should be pursued and completed by a feasibility and utility test by end-users. A subindicator on risk of soil contamination is a gap which remains to fill.

Pesticide Exposure of Residents Living in Wine Regions: Protocol and First Results of the Pestiprev Study.

The PESTIPREV study has been designed to investigate residential exposure to pesticides applied to vines and ultimately propose mitigation measures. A feasibility study was carried out to validate a protocol for measuring six pesticides in three houses located near vineyards in July 2020. Samples included indoor and outdoor surfaces sampled with wipes (n = 214), patches on the resident's skin (n = 7), hand or foot washing (n = 5), and pets sampled using wipes (n = 2). Limits of quantification for wipes ranged between 0.02 ng for trifloxystrobin and 1.50 ng for pyraclostrobin. Tebuconazole and trifloxystrobin were quantified in nearly 100% of the surface samples, whereas the other fungicides were less frequently found (from 39.7% for pyraclostrobin to 55.1% for boscalid). The median surface loadings ranged from 3.13 ng/m2 for benalaxyl to 82.48 ng/m2 for cymoxanil. The pesticides most frequently quantified in hand washing, patch samples, and pet wipes were the same as those quantified on surfaces. Finally, the analyses proved to be successful. The tools developed to collect information on determinants were well completed. The protocol was well received by the participants and appeared to be feasible and relevant to the objective of the PESTIPREV study, although some improvements have been identified. It was applied on a larger scale in 2021 to study the determinants of pesticide exposure.

Impacts of neonicotinoids on biodiversity: a critical review.

Neonicotinoids are the most widely used class of insecticides in the world, but they have raised numerous concerns regarding their effects on biodiversity. Thus, the objective of this work was to do a critical review of the contamination of the environment (soil, water, air, biota) by neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid, thiamethoxam) and of their impacts on terrestrial and aquatic biodiversity. Neonicotinoids are very frequently detected in soils and in freshwater, and they are also found in the air. They have only been recently monitored in coastal and marine environments, but some studies already reported the presence of imidacloprid and thiamethoxam in transitional or semi-enclosed ecosystems (lagoons, bays, and estuaries). The contamination of the environment leads to the exposure and to the contamination of non-target organisms and to negative effects on biodiversity. Direct impacts of neonicotinoids are mainly reported on terrestrial invertebrates (e.g., pollinators, natural enemies, earthworms) and vertebrates (e.g., birds) and on aquatic invertebrates (e.g., arthropods). Impacts on aquatic vertebrate populations and communities, as well as on microorganisms, are less documented. In addition to their toxicity to directly exposed organisms, neonicotinoid induce indirect effects via trophic cascades as demonstrated in several species (terrestrial and aquatic invertebrates). However, more data are needed to reach firmer conclusions and to get a clearer picture of such indirect effects. Finally, we identified specific knowledge gaps that need to be filled to better understand the effects of neonicotinoids on terrestrial, freshwater, and marine organisms, as well as on ecosystem services associated with these biotas.

Main conclusions and perspectives from the collective scientific assessment of the effects of plant protection products on biodiversity and ecosystem services along the land-sea continuum in France and French overseas territories.

Preservation of biodiversity and ecosystem services is critical for sustainable development and human well-being. However, an unprecedented erosion of biodiversity is observed and the use of plant protection products (PPP) has been identified as one of its main causes. In this context, at the request of the French Ministries responsible for the Environment, for Agriculture and for Research, a panel of 46 scientific experts ran a nearly 2-year-long (2020-2022) collective scientific assessment (CSA) of international scientific knowledge relating to the impacts of PPP on biodiversity and ecosystem services. The scope of this CSA covered the terrestrial, atmospheric, freshwater, and marine environments (with the exception of groundwater) in their continuity from the site of PPP application to the ocean, in France and French overseas territories, based on international knowledge produced on or transposable to this type of context (climate, PPP used, biodiversity present, etc.). Here, we provide a brief summary of the CSA's main conclusions, which were drawn from about 4500 international publications. Our analysis finds that PPP contaminate all environmental matrices, including biota, and cause direct and indirect ecotoxicological effects that unequivocally contribute to the decline of certain biological groups and alter certain ecosystem functions and services. Levers for action to limit PPP-driven pollution and effects on environmental compartments include local measures from plot to landscape scales and regulatory improvements. However, there are still significant gaps in knowledge regarding environmental contamination by PPPs and its effect on biodiversity and ecosystem functions and services. Perspectives and research needs are proposed to address these gaps.

Simulating the impact of volatilization on atmospheric concentrations of pesticides with the 3D chemistry-transport model CHIMERE: Method development and application to S-metolachlor and folpet.

A module to simulate the volatilization of pesticides from soils and plants was implemented in the air quality model CHIMERE in order to simulate spatiotemporal distribution of pesticide atmospheric concentrations. Pesticide applications are spatially distributed according to the quantities of pesticides sold per municipality in France (recorded in the French BNVD-S database) and are temporally distributed according to the application periods determined with enquiries. The model was applied to S-metolachlor and folpet. In the first stage of the study, pesticide emissions simulated by the CHIMERE and Volt'Air models are compared. In the second stage, measured concentrations of S-metolachlor and folpet from mid-April to the end of June are compared to the simulation results at the French and PACA (Southeastern region of France) scales. The model can reproduce the spatial distribution of S-metolachlor concentrations (spatial correlation over France of 0.79) with a bias ranging from -50 to 50% for most stations during the application period. The simulation of folpet concentrations remains challenging with a lack of correlation between model results and measurements, that could possibly be due to a lack of precision in the temporalization of applications.

A multiresidue analytical method on air and rainwater for assessing pesticide atmospheric contamination in untreated areas.

The use of pesticides in agriculture to protect crops against pests and diseases generates environmental contamination. The atmospheric compartment contributes to their dispersion at different distances from the application areas and to the exposure of organisms in untreated areas through dry and wet deposition. A multiresidue analytical method using the same TD-GC-MS analytical pipeline to quantify pesticide concentrations in both the atmosphere and rainwater was developed and tested in natura. A Box-Behnken experimental design was used to identify the best compromise in extraction conditions for all 27 of the targeted molecules in rainwater. Extraction yields were above 80% except for the pyrethroid family, for which the recovery yields were around 40-59%. TD-GC-MS proved to be a good analytical solution to detect and quantify pesticides in both target matrices with low limits of quantification. Twelve pesticides (six fungicides, five herbicides and one insecticide) were quantified in rainwater at concentrations ranging from 0.5 ng·L-1 to 170 ng·L-1 with a seasonal effect, and a correlation was found between the concentrations in rainwater and air. The calculated cumulative wet deposition rates are discussed regarding pesticide concentrations in the topsoil in untreated areas for some of the studied compounds.

Determinants of non-dietary exposure to agricultural pesticides in populations living close to fields: A systematic review.

BACKGROUND: There is growing evidence in the scientific literature that individuals living near fields are more exposed to agricultural pesticides than people living further away. OBJECTIVE: The main objective of this systematic review was to identify the non-dietary determinants of pesticide exposure related to the drift pathway in residents living in agricultural areas, including spatial indictors related to agricultural activities, hygiene practices, behaviors and sociodemographic parameters. METHODS: Three databases were consulted (PubMed, Web of sciences, Scopus). At least two experts selected the eligible studies. RESULTS: A total of 27 original studies (2002-2020) fulfilled the eligibility criteria of this review. These publications explored pesticide exposure of individuals through measurements in biological samples (n = 13), environmental samples (n = 11) or both (n = 3). Spatial indicators, including residential proximity to fields, crop acreage around the residence and amounts of pesticides applied in the vicinity were identified as determinants of pesticide exposure in many studies (n = 17), including publications considered to be of very good or good quality (n = 12). Season of spraying tended to increase the levels of pesticides measured in five publications out of seven. Meteorological parameters and physical barriers showed an inconsistent and complex influence on the presence and levels of pesticides in urine samples and house dust. Frequent housekeeping reduced the presence of pesticides at home and consequently in biological matrices in three studies out of six. Finally, the effect of the occupants' sociodemographic characteristics, behaviors, and hygiene practices on the exposure measurement was less well documented and results were fairly inconsistent. DISCUSSION AND CONCLUSION: This study consolidates our knowledge of the determinants influencing pesticide exposure levels in people living in agricultural areas. Nevertheless, the available scientific data is still too limited to serve as a basis for developing risk management measures. More research is needed to improve knowledge of the determinants of exposure.

Assessment of pesticides volatilization potential based on their molecular properties using the TyPol tool.

Following treatment, amounts of pesticides can reach the atmosphere because of spray drift, volatilization from soil or plants, and/or wind erosion. Monitoring and risk assessment of air contamination by pesticides is a recent issue and more insights on pesticide transfer to atmosphere are needed. Thus, the objective of this work was to better understand and assess pesticides emission potential to air through volatilization. The TyPol tool was used to explore the relationships between the global, soil and plant volatilization potentials of 178 pesticides, and their molecular properties. The outputs of TyPol were then compared to atmospheric pesticide concentrations monitored in various French regions. TyPol was able to discriminate pesticides that were observed in air from those that were not. Clustering considering parameters driving the emission potential from soil (sorption characteristics) or plant (lipophilic properties), in addition to vapor pressure, allowed better discrimination of the pesticides than clustering considering all parameters for the global emission potential. Pesticides with high volatilization potential have high total energy, and low molecular weight, molecular connectivity indices and polarizability. TyPol helped better understand the volatilization potential of pesticides. It can be used as a first step to assess the risk of air contamination by pesticides.

Monitoring of pesticides in ambient air: Prioritization of substances.

Despite the richness of data collected on pesticide concentrations in ambient air in France, knowledge on this topic remains partial and heterogeneous in the absence of specific regulations. The population exposure remains thus difficult to estimate; therefore it was necessary to define modalities for implementing national monitoring of pesticides in ambient air in metropolitan France and in the overseas territories. The objective of this work was to identify which active substances (a.s.) have to be monitored in priority. As part of a collective expertise, a group of multidisciplinary experts has developed a method to rank active substances authorised as plant protection products, biocides and antiparasitic agents, which were available on the French market in 2015. A 3-steps approach has been developed. The first step consisted of a theoretical approach based on a hierarchy of substances according to four criteria: (a) national uses, (b) emission potential to the air, (c) persistence in the air, and (d) chronic toxicity. The three first criteria give information on their potential to be present in the atmosphere, and the fourth criterion allows to consider their potential of hazard. The second step was an observational approach based on existing database on pesticide air measurements in France. In the third step, both approaches were combined using decision trees to select priority pesticides. Among the 1316 a.s. first identified from the EU Pesticides database, 90 were selected, among which 43 required metrological and/or analytical development. The experts recommended confirming the relevance of performing a longer term monitoring of these a. s. after a one-year exploratory campaign. The proposed method is reproduceable, transparent, easy to update (e.g. in the light of a change in product authorization), and can be adapted to other agricultural and geographical conditions, and objectives (e.g. monitoring of the ecotoxicological effects of pesticides).

Assessment of residential exposures to agricultural pesticides: A scoping review.

The assessment of residential exposure to agricultural pesticides is a major issue for public health, regulatory and management purposes. In recent years, research into this field has developed considerably. The purpose of this scoping review is to provide an overview of scientific literature characterizing residential exposure to agricultural pesticides and to identify potential gaps in this research area. This work was conducted according to the JBI and PRISMA guidelines. Three databases were consulted. At least two experts selected the eligible studies. Our scoping review enabled us to identify 151 articles published between 1988 and 2019 dealing with the assessment of residential exposure to agricultural pesticides. Of these, 98 (64.9%) were epidemiological studies investigating possible links between pesticide exposure and the onset of adverse health effects, principally cancers and reproductive outcomes. They predominantly used Geographic Information Systems and sometimes surveys or interviews to calculate surrogate exposure metrics, the most common being the amounts of pesticides applied or the surface area of crops around the dwelling. Twenty-six (17.2%) were observational measurement studies conducted to quantify levels of pesticide exposure and identify their possible determinants. These studies assessed exposure by measuring pesticides in biological and environmental matrices, mostly in urines and house dust. Finally, we found only eight publications (5.3%) that quantified the risk to human health due to residential exposure for management purposes, in which exposure was mainly determined using probabilistic models. Pesticide exposure appears to be largely correlated with the spatial organization of agriculture activities in a territory. The determinants and routes of exposure remain to be explored to improve the conduct of epidemiological and risk assessment studies and to help prevent future exposures. Improvement could be expected from small-scale studies combining different methods of exposure assessment.

A new framework to estimate spatio-temporal ammonia emissions due to nitrogen fertilization in France.

In France, agriculture is responsible for 98% of ammonia (NH3) emissions with over 50% caused by nitrogen (N) fertilization. The current French national inventory is based on default emission factors (EF) and does not account for the main variables influencing NH3 emissions. To model the spatio-temporal variability of NH3 emissions due to mineral and organic N fertilization, we implemented a new method named CADASTRE_NH3. The novelty lies in the combined use of two types of resources: the process-based Volt'Air model and geo-referenced and temporally explicit databases for soil properties, meteorological conditions and N fertilization. Simulation units are the Small Agricultural Regions. Several sources of information were combined to obtain N fertilization management: census and surveys of the French Ministry of Agriculture, statistics on commercial fertilizer deliveries, and French expertise on physicochemical properties of organic manure. The practical interest of this new framework was illustrated for France during the crop year 2005/06. Aggregation at crop year level showed a reasonable agreement between estimated values derived from CADASTRE_NH3 and those from the French inventory method, for N and ammoniacal-N (TAN) application rates, total NH3 emissions and NH3 EF. Discrepancies were large for organic manure only; national TAN application rates and NH3 emissions were 62-63% lower with CADASTRE_NH3. This was due to divergences in the representation of cattle farm yard manure and in the TAN:N ratio of solid manure. Annual emissions for fertilization in France were estimated to be 270 Gg NH3, 29% lower than the French national inventory estimate. At the regional level, organic manure contributed to 73% of field NH3 emissions in intensive livestock husbandry areas and to 41% in the other areas. The CADASTRE_NH3 framework can be seen as a Tier 3 approach able to estimate specific regional EF for different mineral fertilizers and organic manure.