Life cycle toxicity assessment of pesticides used in integrated and organic production of oranges in the Comunidad Valenciana, Spain

Multi-season environmental life cycle assessment of lemons: A case study in south Uruguay

Lemons are a relevant agricultural commodity in Uruguay, mainly exported for fresh consumption. Food eco-labels are on the rise worldwide as consumers and authorities are increasingly demanding them. However, there is a lack of scientific studies estimating the environmental impacts of Uruguayan citrus production. This study aims to assess the environmental performance of lemon production in Uruguay taking into account inter-seasonal variability by applying the Life Cycle Assessment (LCA) methodology and following the Environmental Product Declarations (EPDs) guidelines. A cradle-to-farm gate assessment was carried out based on both mass and spatial functional units. Primary data was gathered from a representative orchard of the region for four harvest seasons (2016-2020). Environmental impact categories recommended by EN 15804 + A2 standard were assessed. Specifically, blue water scarcity was assessed using the AWARE method. In addition, human and freshwater ecotoxicity were assessed using USEtox. Results show that on-field emissions and input production are critical for most of the categories assessed (on average, 84% CC, 88% Ac, 98% MEu, and 85% TEu), whereas blue water consumed for irrigation is the main hotspot in blue water scarcity (86%, on average). As expected, inter-seasonal impacts present higher variability when expressing results per tonne vs. per hectare because, although agricultural inputs applied are the same, climatic variability influences water requirements and also affects yield. Blue water scarcity exhibits the highest variability because water consumption depends strongly on agroclimatic conditions, mainly on rain and irrigated water and on water dynamics in soil. Nitrate leaching is a key emission for freshwater eutrophication and, to a minor degree, for climate change, which also depends on the water dose and timing, either from rain or irrigation. Optimising the N application is crucial to minimise on-field emissions, a hotspot in the present study. Along these lines, improved agricultural practices are suggested to enhance the environmental profile of Uruguayan lemons. Replacement or minimisation of the dose of certain inputs (e.g., copper oxide) through the implementation of complementary agricultural practices is suggested. Finally, up-to-date techniques to decrease blue water scarcity are proposed. Methodological recommendations for future studies include modelling N emissions using mechanistic models, incorporating potential reductions in N emissions due to certain agricultural practices, and harmonizing the methodology to quantify water consumption. This study sets a baseline LCA for Uruguayan citrus fruit production. It highlights inter-seasonal variability as an issue to be considered, even when agricultural practices do not change, and especially relevant in countries with high climatic variability like Uruguay. The study also provides scientific and quantitative evidence to support the environmental decisions of both citrus producers and consumers.

Dissipation kinetics, residue modeling and human intake of endosulfan applied to okra (Abelmoschus esculentus)

The non-judicious application of the harmful pesticide endosulfan on okra, one of India's most consumed vegetable crops, has resulted in the frequent detection of residues in food samples. This can lead to resistance and the resurgence of various pests and diseases. In this context, combined dissipation and residue dynamics of different endosulfan components or mixtures (isomers and metabolites) in crop compartments are not yet well understood. To address this research gap, the present study evaluates the dissipation and persistence behavior of different endosulfan isomers (alpha-, beta-isomers) and major metabolite (endosulfan sulfate) on okra during 2017 and 2018. The half-life of endosulfan on okra leaves was found to be between 1.79 and 3.47 days. Half of the endosulfan deposits on okra fruits at the recommended doses were dissipated after 2.39 days compared to 1.99 days at double recommended doses (mean of 2017 and 2018 residue data). Measured endosulfan residues were evaluated against the dynamic plant uptake model dynamiCROP. The better fits were observed between modeled and measured residues for fruits (R² from 0.84 to 0.96 and residual standard error (ER) between 0.6 and 1.47) as compared to leaves (R² from 0.57 to 0.88). We also report fractions of endosulfan components ingested by humans after crop harvest. Intake fractions range from 0.0001-7.2 g_intake/kg of applied pesticide. Our results can evaluate pesticide residues in different crops grown for human consumption, including their isomers and metabolites. They can be combined with dose-response information to evaluate human exposure and/or health risk assessment.

Behavioral Response in Toxicity Assessment of the Insecticide Decis® 2.5 EC toward Freshwater Zooplankton

Chemical crop protection agents are widely applied in modern agricultural practice. As a result of surface runoff, these insecticides penetrate into rivers, ponds, and lakes, where they become a serious threat to aquatic organisms. The aim of the study was to determine the toxicity of increasing concentrations of the insecticide Decis® 2.5 EC to Daphnia magna and Heterocypris incongruens, which are components of freshwater zooplankton. The observed effect was immobilization of organisms, which were not able to swim after gentle agitation of the liquid for 15 sec. It was found that up to 135 min, increasing Decis® 2.5 EC concentrations inhibited the swimming of tested organisms. Initially, up to 135 min, Heterocypris incongruens was more sensitive to the tested insecticide. After 135 min of the experiment, ostracods acclimatized to the tested xenobiotic. However, after 360 min, the immobilization of organisms increased proportionally to the concentrations of Decis® 2.5 EC. The most toxic concentrations were 15 × 10−3% and 30 × 10−3%. The lowest observed effect concentration of Decis® 2.5 EC that reduced the swimming of daphnia and ostracod by more than 20% was >0.91 × 10−3% (0.23 mg L−1 of deltamethrin). This experiment demonstrated that Daphnia magna and Heterocypris incongruens are good bioindicators of freshwaters polluted with Decis® 2.5 EC.

Human Health and Ecosystem Quality Benefits with Life Cycle Assessment Due to Fungicides Elimination in Agriculture

Industrial agriculture results in environmental burdens due to the overuse of fertilizers and pesticides. Fungicides is a class of pesticides whose application contributes (among others) to human toxicity and ecotoxicity. The European Union aims to increase organic agriculture. For this reason, this work aims to analyze climate change, freshwater ecotoxicity, terrestrial ecotoxicity, human toxicity, (terrestrial) acidification, and freshwater eutrophication impacts of fungicides and calculate expected benefits to human health (per European citizen) and ecosystem quality (terrestrial) with life cycle assessment (LCA) during crop production. The Scopus database was searched for LCA studies that considered the application of fungicides to specific crops. The analysis shows how many systemic and contact fungicides were considered by LCA studies and what was the applied dosage. Furthermore, it shows that fungicides highly contribute to freshwater ecotoxicity, terrestrial ecotoxicity, human toxicity, and freshwater eutrophication for fruits and vegetables, but to a low extent compared to all considered environmental impacts in the case of cereals and rapeseed. Expected benefits to human health and ecosystem quality after fungicides elimination are greater for fruits and vegetables, ranging between 0 to 47 min per European citizen in a year and 0 to 90 species per year, respectively.

Pesticide bioremediation by Trametes versicolor: Application in a fixed-bed reactor, sorption contribution and bioregeneration

Although immobilization on lignocellulosic materials has recently become a promising strategy in the fungal-based technology for micropollutant bioremediation, research evidence in this area is still scarce and significant knowledge gaps need to be addressed. In this study, Trametes versicolor immobilized on Quercus ilex wood chips was initially proposed to remove two pesticides, diuron and bentazon, from real agricultural wastewater. Thus, a bioremediation treatment was performed in a fixed-bed bioreactor at two empty bed contact times (EBCT) of 1 and 3 days. Bentazon saturation was achieved after 5 EBCTs, while diuron sorption remained below 50% even after 40 days of treatment. The differences in diuron and bentazon removals were linked to their different hydrophobicity and thus, affinity for wood. However, in any case, the sorption contribution of wood was found to be predominant compared to fungal biodegradation. These results motivated a comprehensive study to evaluate the pollutant sorption capacity of wood. Afterwards, pesticide-contaminated wood was successfully bioregenerated by T. versicolor in a biopile-like system, reaching high fungal colonization (up to 0.2451 mg ergosterol·g^-1 dry weight), degradation rate (up to 2.55 mg·g^-1·d^-1) and degradation yields (up to 92.50%). The combined treatment consisting of the fixed-bed bioreactor followed by the re-inoculated biopile showed the best performance in terms of fungal content and pesticide degradation. This is an important step toward the implementation of fungal-based technology for the removal of pesticides from agricultural water.

Environmental Impact Assessment of Agricultural Production Using LCA: A Review

Life cycle impact assessment (LCA) provides a better understanding of the energy, water, and material input and evaluates any production system’s output impacts. LCA has been carried out on various crops and products across the world. Some countries, however, have none or only a few studies. Here, we present the results of a literature review, following the PRISMA protocol, of what has been done in LCA to help stakeholders in these regions to understand the environmental impact at different stages of a product. The published literature was examined using the Google Scholar database to synthesize LCA research on agricultural activities, and 74 studies were analyzed. The evaluated papers are extensively studied in order to comprehend the various impact categories involved in LCA. The study reveals that tomatoes and wheat were the major crops considered in LCA. The major environmental impacts, namely, human toxicity potential and terrestrial ecotoxicity potential, were the major focus. Furthermore, the most used impact methods were CML, ISO, and IPCC. It was also found that studies were most often conducted in the European sector since most models and databases are suited for European agri-food products. The literature review did not focus on a specific region or a crop. Consequently, many studies appeared while searching using the keywords. Notwithstanding such limitations, this review provides a valuable reference point for those practicing LCA.

Chemical footprint of pesticides used in citrus orchards based on canopy deposition and off-target losses

The application of chemical pesticides is one of the main practices in citrus orchards. But during this operation, a considerable amount of sprayed volume is emitted to off-target areas using air-blast sprayers. The present study aimed to investigate pesticides' toxicological impacts in citrus orchards through determining the proportion of pesticides in different areas (air, soil, and canopy), which facilitate toxicity assessment of pesticides in citrus orchards. In this study, human toxicity and freshwater ecotoxicity impacts were assessed using USEtox 2.1 modeling approach for five active ingredients used in citrus orchards in the south of Iran. Different spraying scenarios were defined based on two types of nozzles (Hallow-cone and Teejet full-cone) and three levels of pressure (30, 40, and 50 bar) in two orchards with different row spacing. Results showed that only 26-37% of spray solution is deposited on the target with much loss to areas between tree canopies on the row. Scenario 1 (Hallow-cone nozzle with spraying pressure as 30 bar) shows the highest spraying efficiency in the both orchards (37% and 34% for Tangerine and Lemon orchards, respectively). Air emissions were obtained around 17 and 18% for hollow-cone and Teejet full-cone nozzles, respectively. The final inventory was obtained considering evaporation rate of active ingredients from soil surface and leaves. Based on the results obtained from toxicological impact assessment, Thiacloprid and Carbendazim had the highest negative environmental impacts on human health and freshwater aquatic ecosystem, respectively. Based on the results, soil emissions were identified as more critical than air emissions in terms of environmental consequences. It can be attributed to the higher characterization factor and deposition on the soil in comparison to the air. The present study provided well-founded information on the environmental performance of production systems by estimating the relevant emissions of pesticides to different compartments and determined the human and freshwater toxicity impact profiles, which assist decision-makers and LCA-practitioners to have a better perspective about pesticides behavior in receiving compartment.

Life Cycle Assessment of Variable Rate Fertilizer Application in a Pear Orchard

Precision Agriculture (PA) is a crop site-specific management system that aims for sustainability, adopting agricultural practices more friendly to the environment, like the variable rate application (VRA) technique. Many studies have dealt with the effectiveness of VRA to reduce nitrogen (N) fertilizer, while achieving increased profit and productivity. However, only limited attention was given to VRA’s environmental impact. In this study an International Organization for Standardization (ISO) based Life Cycle Assessment (LCA) performed to identify the environmental effects of N VRA on a small pear orchard, compared to the conventional uniform application. A Cradle to Gate system with a functional unit (FU) of 1 kg of pears was analyzed including high quality primary data of two productive years, including also the non-productive years, as well as all the emissions during pear growing and the supply chains of all inputs, projecting them to the lifespan of the orchard. A methodology was adopted, modelling individual years and averaging over the orchard’s lifetime. Results showed that Climate change, Water scarcity, Fossil fuels and Particulate formation were the most contributing impact categories to the overall environmental impact of the pear orchard lifespan, where climate change and particulates were largely determined by CO2, N2O, and NH3 emissions to the air from fertilizer production and application, and as CO2 from tractor use. Concerning fertilization practice, when VRA was combined with a high yield year, this resulted in significantly reduced environmental impact. LCA evaluating an alternative fertilizer management system in a Greek pear orchard revealed the environmental impact reduction potential of that system.

Assessing the environmental impact of Spanish vineyards in Utiel-Requena PDO: The influence of farm management and on-field emission modelling

Environmental studies into wine from different protected designations of origin (PDO) highlight farming and packaging stages as those contributing the most to the total environmental impacts of this product. However, farming impact, not only depends on the agricultural practices but also on data quality and modelling complexity. By using the life cycle assessment methodology, a twofold goal is aimed. Firstly, to analyse the environmental profile of the most widespread viticultural practices in the Utiel-Requena PDO (Spain). The second aim is to evaluate the differences between the environmental impacts estimated by means of modelling approaches using generic information (Baseline modelling) versus those using site-specific information (Alternative modelling). As regards the agricultural practices and grape cultivars, eight systems were defined and assessed per kg of grape at the farm gate. The differences between farming systems and modelling approaches were statistically assessed. The results show that, regardless of the grape cultivar, organic systems are more environmentally friendly than the conventional ones (on average, the greatest differences occur in the ionizing radiation, marine eutrophication and land use, being the values for organic vineyards 1678%, 648% and 171% lower than those of the conventional ones, respectively), the results for the Bobal cultivar being better than those for the Tempranillo because of the higher yield (differences in yield around 1.500 kg ha^-1). The use of site-specific modelling approaches guarantees the precision of the analysis; however, for some impact categories, namely climate change, fine particulate matter formation, marine eutrophication and terrestrial acidification, the possibility of using general methodologies is open; in this way, the modelling efforts can be minimised, and the results would be consistent with those of more specific methodologies. The results also underline the need for a consensus within LCA practitioners on which methodologies to use in order to estimate on-field emissions taking into account both complexity reduction and accuracy improvement.

Environmental impacts on water resources from summer crops in rainfed and irrigated systems

Irrigation is an intensification technology to increase productivity in agricultural systems, but the impacts of irrigation on the environmental performance of crops are not well understood. We evaluated impacts on water use and quality of rainfed and irrigated systems for corn and soybean production in temperate South America using nonparametric ANOVA tests for small sample sizes. We modeled blue water footprint, ecotoxicity, N and P balance, and eutrophication potential for six farms producing corn and soybean in rainfed and irrigated systems in Uruguay. Crop yields were 5948 and 7862 kg ha^-1 for corn and 2482 and 3423 kg ha^-1 for soybean, under rainfed and irrigation, respectively. The average blue water footprint for irrigated systems was 264 m³ ton^-1 and zero for rainfed systems, with no difference between corn and soybean. The ecotoxicity was greater for soybean than for corn (1679 vs 325 CTUe kg^-1) but there were no statistically significant differences in ecotoxicity between rainfed and irrigated systems. Based on Usetox methodology, insecticides had a greater ecotoxic effect (3.2 × 10⁶ CTUe ha^-1) than herbicides (7.3 × 10⁴ CTUe ha^-1), despite the lower doses applied (insecticides: 0.51 kg ha^-1; herbicides: 6.83 kg ha^-1). The aquatic eutrophication potential (based on Impact 2002 + methodology) among rainfed and irrigated systems presented no differences (29 vs 24 kgPO_4-eq ha^-1 for corn and 19 vs 27 kgPO_4-eq ha^-1 for soybean). The standardized environmental impacts for corn calculated per ha were similar than those per kg of grain when comparing rainfed vs irrigated systems. For soybean, however, standardized environmental impacts per ha were greater in the irrigated than in the rainfed systems, but were similar per kg of grain (except for water footprint). In summary, irrigation resulted in higher productivity and increased blue water footprint than rainfed, but in the set of farms analyzed it did not significantly increase inputs use, so no differences were detected in nutrient balance, eutrophication potential, or ecotoxicity. Soybeans had greater environmental impacts than corn in ecotoxicity and N excess per unit of area, but no statistically significant difference was found in the other indicators. These indicators may be useful as a predictive tool for resource management. Decision makers should consider the trade-offs between productivity, water use, and water quality when using irrigation for intensification of crop production.

Environmental impacts of organic and conventional agricultural products--are the differences captured by life cycle assessment?

Comprehensive assessment tools are needed that reliably describe environmental impacts of different agricultural systems in order to develop sustainable high yielding agricultural production systems with minimal impacts on the environment. Today, Life Cycle Assessment (LCA) is increasingly used to assess and compare the environmental sustainability of agricultural products from conventional and organic agriculture. However, LCA studies comparing agricultural products from conventional and organic farming systems report a wide variation in the resource efficiency of products from these systems. The studies show that impacts per area farmed land are usually less in organic systems, but related to the quantity produced impacts are often higher. We reviewed 34 comparative LCA studies of organic and conventional agricultural products to analyze whether this result is solely due to the usually lower yields in organic systems or also due to inaccurate modeling within LCA. Comparative LCAs on agricultural products from organic and conventional farming systems often do not adequately differentiate the specific characteristics of the respective farming system in the goal and scope definition and in the inventory analysis. Further, often only a limited number of impact categories are assessed within the impact assessment not allowing for a comprehensive environmental assessment. The most critical points we identified relate to the nitrogen (N) fluxes influencing acidification, eutrophication, and global warming potential, and biodiversity. Usually, N-emissions in LCA inventories of agricultural products are based on model calculations. Modeled N-emissions often do not correspond with the actual amount of N left in the system that may result in potential emissions. Reasons for this may be that N-models are not well adapted to the mode of action of organic fertilizers and that N-emission models often are built on assumptions from conventional agriculture leading to even greater deviances for organic systems between the amount of N calculated by emission models and the actual amount of N available for emissions. Improvements are needed regarding a more precise differentiation between farming systems and regarding the development of N emission models that better represent actual N-fluxes within different systems. We recommend adjusting N- and C-emissions during farmyard manure management and farmyard manure fertilization in plant production to the feed ration provided in the animal production of the respective farming system leading to different N- and C-compositions within the excrement. In the future, more representative background data on organic farming systems (e.g. N content of farmyard manure) should be generated and compiled so as to be available for use within LCA inventories. Finally, we recommend conducting consequential LCA - if possible - when using LCA for policy-making or strategic environmental planning to account for different functions of the analyzed farming systems.

Seasonal input of regulated and emerging organic pollutants through surface watercourses to a Mediterranean coastal lagoon

Seasonal input of organic pollutants through El Albujón Watercourse to the Mar Menor lagoon was estimated from Spring 2009 to Winter 2010, including regular periods and two flash flood events. 82 semivolatile organic pollutants (persistent organic pollutants, different groups of pesticides and others) were determined by stir bar sorptive extraction and thermal desorption followed by capillary gas chromatography coupled to mass spectrometry from surface waters with quantification limits of a few ngL(-1). Pesticide concentrations varied significantly along the watercourse due to the presence of different sources (groundwaters, wastewater effluent, tributary contributions, brackish waters, etc.) and physicochemical/biological processes that take place simultaneously. The most commonly detected analytes were propyzamide, triazine compounds and chlorpyrifos. A clear seasonal pattern has been detected, with a predominance of insecticides during Summer and of herbicides during Winter. The input of pesticides through this watercourse is particularly relevant during periods of heavy rain, representing more than 70% of total yearly input for many of them.