Do rainfall characteristics affect the export of copper, zinc and synthetic pesticides in surface runoff from headwater catchments?

Unseen streams tracing emerging contaminants from stormwater to surface water: A brief review

Emerging contaminants (ECs) have raised global concern due to their adverse effect on ecosystems and human health. However, the occurrence and transport of ECs in stormwater remain unclear. The impact of ECs from stormwater on surface water quality and ecosystem health is also poorly documented. In this review, we examined the variations in EC concentrations in surface water resulting from stormwater. During the wet weather, the concentrations of most investigated ECs, e.g., microplastics, per- and polyfluoroalkyl substances, and vehicle-related compounds, significantly increase in surface water, indicating that stormwater may be a critical source of these contaminants. Furthermore, the potential pathways of ECs from stormwater enter surface water are outlined. Studies demonstrate that surface runoff and combined sewer overflows are important pathways for ECs, with discharges comparable to or exceeding those from wastewater treatment plants. Illicit connection also plays an important part in elevated EC concentrations in surface water. Overall, our findings underscore the importance of stormwater as a source for ECs in surface waters, and urge for increased emphasis on, and reinforcement of, stormwater monitoring and control measures to minimize the transport of ECs into receiving water bodies.

The use of copper as plant protection product contributes to environmental contamination and resulting impacts on terrestrial and aquatic biodiversity and ecosystem functions

Copper-based plant protection products (PPPs) are widely used in both conventional and organic farming, and to a lesser extent for non-agricultural maintenance of gardens, greenspaces, and infrastructures. The use of copper PPPs adds to environmental contamination by this trace element. This paper aims to review the contribution of these PPPs to the contamination of soils and waters by copper in the context of France (which can be extrapolated to most of the European countries), and the resulting impacts on terrestrial and aquatic biodiversity, as well as on ecosystem functions. It was produced in the framework of a collective scientific assessment on the impacts of PPPs on biodiversity and ecosystem services in France. Current science shows that copper, which persists in soils, can partially transfer to adjacent aquatic environments (surface water and sediment) and ultimately to the marine environment. This widespread contamination impacts biodiversity and ecosystem functions, chiefly through its effects on phototrophic and heterotrophic microbial communities, and terrestrial and aquatic invertebrates. Its effects on other biological groups and biotic interactions remain relatively under-documented.

Dissipation of pesticides and responses of bacterial, fungal and protistan communities in a multi-contaminated vineyard soil

The effect of pesticide residues on non-target microorganisms in multi-contaminated soils remains poorly understood. In this study, we examined the dissipation of commonly used pesticides in a multi-contaminated vineyard soil and its effect on bacterial, fungal, and protistan communities. We conducted laboratory soil microcosm experiments under varying temperature (20°C and 30°C) and water content (20 % and 40 %) conditions. Pesticide dissipation half-lives ranged from 27 to over 300 days, depending on the physicochemical properties of the pesticides and the soil conditions. In both autoclaved and non-autoclaved soil experiments, over 50 % of hydrophobic pesticides (dimethomorph > isoxaben > simazine = atrazine = carbendazim) dissipated within 200 days at 20°C and 30°C. However, the contribution of biodegradation to the overall dissipation of soluble pesticides (rac-metalaxyl > isoproturon = pyrimethanil > S-metolachlor) increased to over 75 % at 30°C and 40 % water content. This suggests that soluble pesticides became more bioavailable, with degradation activity increasing with higher temperature and soil water content. In contrast, the primary process contributing to the dissipation of hydrophobic pesticides was sequestration to soil. High-throughput amplicon sequencing analysis indicated that water content, temperature, and pesticides had domain-specific effects on the diversity and taxonomic composition of bacterial, fungal, and protistan communities. Soil physicochemical properties had a more significant effect than pesticides on the various microbial domains in the vineyard soil. However, pesticide exposure emerged as a secondary factor explaining the variations in microbial communities, with a more substantial effect on protists compared to bacterial and fungal communities. Overall, our results highlight the variability in the dissipation kinetics and processes of pesticides in a multi-contaminated vineyard soil, as well as their effects on bacterial, fungal, and protistan communities.

Sources, effects and present perspectives of heavy metals contamination: Soil, plants and human food chain

Heavy metal (HM) poisoning of agricultural soils poses a serious risk to plant life, human health, and global food supply. When HM levels in agricultural soils get to dangerous levels, it harms crop health and yield. Chromium (Cr), arsenic (As), nickel (Ni), cadmium (Cd), lead (Pb), mercury (Hg), zinc (Zn), and copper (Cu) are the main heavy metals. The environment contains these metals in varying degrees, such as in soil, food, water, and even the air. These substances damage plants and alter soil characteristics, which lowers crop yield. Crop types, growing circumstances, elemental toxicity, developmental stage, soil physical and chemical properties, and the presence and bioavailability of heavy metals (HMs) in the soil solution are some of the factors affecting the amount of HM toxicity in crops. By interfering with the normal structure and function of cellular components, HMs can impede various metabolic and developmental processes. Humans are exposed to numerous serious diseases by consuming these affected plant products. Exposure to certain metals can harm the kidneys, brain, intestines, lungs, liver, and other organs of the human body. This review assesses (1) contamination of heavy metals in soils through different sources, like anthropogenic and natural; (2) the effect on microorganisms and the chemical and physical properties of soil; (3) the effect on plants as well as crop production; and (4) entering the food chain and associated hazards to human health. Lastly, we identified certain research gaps and suggested further study. If people want to feel safe in their surroundings, there needs to be stringent regulation of the release of heavy metals into the environment.

Evaluating pesticide degradation in artificial wetlands with compound-specific isotope analysis: A case study with the fungicide dimethomorph

Pesticide degradation in wetland systems intercepting agricultural runoff is often overlooked and mixed with other dissipation processes when assessing pesticide concentrations alone. This study focused on the potential of compound-specific isotope analysis (CSIA) to estimate pesticide degradation in a stormwater wetland receiving pesticide runoff from a vineyard catchment. The fungicide dimethomorph (DIM), with diastereoisomers E and Z, was the prevalent pesticide in the runoff entering the wetland from June to September 2020. DIM Z, the most commonly detected isomer, exhibited a significant change (Δ(13C) > 3 ‰) in its carbon isotopic composition in the wetland water compared to the runoff and commercial formulation, which indicated degradation. Laboratory DIM degradation assays, including photodegradation and biodegradation in oxic wetland water with and without aquatic plants and in anoxic sediments, indicated that DIM degradation mainly occurred in the wetland sediments. The rapid degradation of both DIM isomers (E:t1/2 = 1.2 ± 0.6, Z: t1/2 = 1.5 ± 0.8 days) in the wetland sediment led to significant carbon isotopic fractionation (εDIM-E = -3.0 ± 0.6 ‰, εDIM-Z = -2.0 ± 0.2 ‰). In contrast, no significant isotope fractionation occurred during DIM photodegradation, despite the rapid isomerization of the E isomer to the Z isomer and a half-life of 15.3 ± 2.2 days for both isomers. DIM degradation was slow (E: t1/2 = 56-62 days, Z: t1/2 = 82-103 days) in oxic water with plants, while DIM persisted (120 days) in water without plants. DIM CSIA was thus used to evaluate the in situ biodegradation of DIM Z in the wetland. The DIM Z degradation estimates based on a classical concentration mass balance (86-94 %) were slightly higher than estimates based on the isotopic mass balance (61-68 %). Altogether, this study shows the potential of CSIA to conservatively evaluate pesticide degradation in wetland systems, offering a reliable alternative to classical labor-intensive mass balance approaches.).

Contamination characteristics in runoff fractions from a nuclear facility in São Paulo, Brazil

The stormwater runoff may act as a nonpoint pollutant source and contributes to aquatic ecosystem quality decay in urban environments. The aim of this work was to evaluate the runoff characteristics on the transport of total solids and total metals, as well as pH and conductivity responses during the rainfall evolution. During 2017 and 2018, 12 rain events were monitored in 4 sampling stations at a car parking lot located at Nuclear and Energy Research Institute (IPEN/CNEN) in São Paulo/Brazil. A 4-chamber integrated collector allowed the sequential/temporal runoff evolution assessment. The runoff composition, in decreasing order of quantities, was Ca > K > Mg > Si > Al > Fe > Na > Zn > Mn > Sr > Ti > Mo > V > Cu > B > Pb > Ni > Ce > Sb > Cr > La > U > Th > Cd. The amount of total solids, Al, and Fe exceeded the Brazilian water quality standards. Principal component analysis (PCA) identified the elemental clusters linked to the facility activity, soil, and traffic/atmospheric-related deposition. The results show that the runoff characteristics could be differentiated by pollutant source. Factors such as seasonal variation, rain event intensity, air mass from oceanic or continental origin, spatial distribution inside the monitoring area, and the intensity of the first flush must be considered in order to disentangle the elemental clusters and pollution source contributions. In winter, continental air masses were associated with higher concentrations of heavy metals in the surface runoff. Spatial changes with no seasonal variation were observed for U, Th, La, and Ce.

Establishing the extent of pesticide contamination in Irish agricultural soils

To establish meaningful and sustainable policy directives for sustainable pesticide use in agriculture, baseline knowledge of pesticide levels in soils is required. To address this, five pesticides and one metabolite widely used in Irish agriculture and five neonicotinoid compounds pesticides were screened from soils from 25 fields. These sites represented a diversity of soil and land use types. Prothioconazole was detected in 16 of the 18 sites where it had been recently applied, with the highest maximum concentration quantified of 46 μg/kg. However, a week after application only four fields had prothioconazole concentrations above the limit of quantification (LOQ). Fluroxypyr was applied in 11 sites but was not detected above LOQ. Glyphosate and AMPA were not detected. Interestingly, neonicotinoids were detected in 96% of all sampling sites, even though they were not reported as recently applied. Excluding neonicotinoids, 60% of sites were found to contain pesticide residues of compounds that were not previously applied, with boscalid and azoxystrobin detected in 15 of the 25 sites sampled. The total number of pesticides detected in Irish soils were significantly negatively correlated with clay fraction, while average pesticide concentrations were significantly positively correlated with log Kow values. 17 fields were found to have total pesticide concentrations in excess of 0.5 μg/kg, even when recently applied pesticides were removed from calculations. Theoretical consideration of quantified pesticides determined that azoxystrobin has high leaching risk, while boscalid, which was detected but not applied, has an accumulation risk. This information provides insight into the current level of pesticide contamination in Irish agricultural soil and contributes to the European-level effort to understand potential impacts of pesticide contamination in soil.

Dimethomorph degradation in vineyards examined by isomeric and isotopic fractionation

Knowledge of the degradation extent and pathways of fungicides in the environment is scarce. Fungicides may have isomers with distinct fungal-control efficiency, toxicity and fate in the environment, requiring specific approaches to follow up the degradation of individual isomers. Here we examined the degradation of the widely used fungicide dimethomorph (DIM) in a vineyard catchment using ratios of carbon stable isotopes (δ¹³C) and E/Z isomer fractionation (IF(Z)). In a microcosm laboratory experiment, DIM degradation half-life in soil was 20 ± 3 days, and was associated with significant isomeric (ΔIF(Z) = +30%) and isotopic (Δδ¹³C up to 7‰) fractionation. This corresponds to an isomer enrichment factor of ε_IR = -54 ± 6%, suggesting isomer selectivity and similar carbon stable isotopic fractionation values of ε_DIM-(Z) = -1.6 ± 0.2‰ and ε_DIM-(E) = -1.5 ± 0.2‰. Isomeric and isotopic fractionation values were used to estimate DIM degradation in topsoil and transport in a vineyard catchment over two wine-growing seasons. DIM concentrations following DIM application were up to 3 μg g^-1 in topsoil and 29 μg L^-1 in runoff water at the catchment outlet. Accordingly, the IF(Z) and δ¹³C values of DIM in soil were similar to those observed in DIM commercial formulations. The gradual enrichments in DIM-(Z) and ¹³C of the residual DIM in soil indicated DIM biodegradation over time. DIM biodegradation estimated based on E/Z isomer and carbon stable isotope ratios in topsoil and runoff water ranged from 0% after DIM application up to 100% at the end of the wine-growing season. DIM biodegradation was overestimated compared to conventional approaches relying on DIM mass balance, field concentrations and half-lives. Altogether, our study highlights the usefulness of combining carbon stable isotopes, E/Z isomers and classical approaches to estimate fungicide degradation at the catchment scale, and uncovers difficulties in using laboratory-derived values in field studies.

Mapping risks associated with soil copper contamination using availability and bio-availability proxies at the European scale

Soil contamination by trace elements like copper (Cu) can affect soil functioning. Environmental policies with guidelines and soil survey measurements still refer to the total content of Cu in soils. However, Cu content in soil solution or free Cu content have been shown to be better proxies of risks of Cu mobility or (bio-)availability for soil organisms. Several empirical equations have been defined at the local scale to predict the amount of Cu in soil solution based on both total soil Cu content and main soil parameters involved in the soil/solution partitioning. Nevertheless, despite the relevance for risk assessment, these equations are not applied at a large spatial scale due to difficulties to perform changes from local to regional. To progress in this challenge, we collected several empirical equations from literature and selected those allowing estimation of the amount of Cu in solution, used as a proxy of available Cu, from the knowledge of both total soil Cu content and soil parameters. We did the same for the estimation of free Cu in solution, used as a proxy of bio-available Cu. These equations were used to provide European maps of (bio-)available Cu based on the one of total soil Cu over Europe. Results allowed comparing the maps of available and bio-available Cu at the European scale. This was done with respective median values of each form of Cu to identify specific areas of risks linked to these two proxies. Higher discrepancies were highlighted between the map of bio-available Cu and the map of soil total Cu compared to the Cu available map. Such results can be used to assess environmental-related issues for land use planning.

Process, influencing factors, and simulation of the lateral transport of heavy metals in surface runoff in a mining area driven by rainfall: A review

The lateral transport of heavy metals can expand the scope of original contamination, and an accurate prediction of heavy metal migration is necessary to control heavy metal transport. However, previous studies have mainly focused on the migration of soil pollutants in the runoff-soil-groundwater system, whereas research on the lateral migration of heavy metals in surface soil driven by rainfall is relatively scarce. Therefore, in this study we analyzed the horizontal migration of water-soluble heavy metals with surface runoff and non-water-soluble heavy metals with sediment particles, investigated the main factors affecting the processes of runoff and sediment transport and the main factors affecting the mobility of heavy metals in soils, summarized the existing methods for the simulation of heavy metal transportation. The construction of a lateral migration model based on the migration mechanism of soil heavy metals, the hydrological model, and the application of the lateral migration model should be the focus of future research. This study provides a theoretical basis for establishing a model of the lateral migration of soil heavy metals and is of great significance for the prevention and control of the risks related to the lateral migration of soil heavy metals.

Using bibliometrics to analyze the state of art of pesticide use in vineyard agrosystems: a review

The production of wine dates to ancient civilization and has heavily influenced different landscapes around the globe. Nowadays, wine is still an important sector in terms of land use and income source in many countries, more specifically in the European Mediterranean region. However, to control pests and regulate wine growth, the extensive use of pesticides is common. The effects and persistence of agrochemicals in the environment is well known and defined in scientific literature as well as the environmental and human health risks of these compounds. The purpose of this review was to do a state of art of worldwide production of academic literature using bibliometric principles and analysis to identify thematic areas of this type of agriculture, and its challenges in a changing world. For this review, the focus is on current practices to see what may evolve for more sustainable viticulture. It was found that the three main producers of wine, i.e., Spain, France, and Italy, are also three top producers of scientific literature on this topic. The use of bibliometric methodologies defined the main thematic areas on this subject as follows: soil-plant transfer of agrochemicals, heavy metal accumulation in vineyard soils, management practices in viticulture, water pollution transport, effects of viticulture on the living part of soil, sustainable alternatives to pesticides. We found that Spain, France, and Italy work the most on developing sustainable alternatives for agricultural practices; however, sustainable alternatives and practices were also the least developed thematic in general.

Ageing of copper, zinc and synthetic pesticides in particle-size and chemical fractions of agricultural soils

The transformation and mobility of heavy metals and synthetic pesticides in soil depend on ageing, involving their chemical and physical distributions among soil fractions over time. Heavy metals and synthetic pesticides often co-occur in soil, although their ageing is usually evaluated separately and in bulk soil. Here, contrasting vineyard and crop soils were spiked with copper (Cu; 700 mg kg^-1) and zinc (Zn; 200 mg kg^-1) a and/or synthetic pesticides (5 mg kg^-1), i.e., the fungicide metalaxyl (MTY) and herbicide S-metolachlor (SMET), to evaluate within 200 days their distribution among soil physical and chemical fractions. More than 90% of MTY and SMET in soil was released into the water phase, even 200 days after spiking. This emphasizes the potential mobilization of MTY and SMET from the soil following field application. MTY, SMET, Cu and Zn were associated mainly with the silt fraction and to a lesser extent (<30%) with the sand and clay fractions. Overall, the ageing of MTY, SMET, Cu and Zn in agricultural soil was affected mainly by the soil type and sterilization and only to a minor extent by their co-occurrence. Sorption controlled the dissipation of MTY and SMET in soil, while biodegradation contributed to less than 10%. A large fraction (37 ± 2%) of Cu was associated with Fe oxides after 200 days of ageing, while Zn was found (33 ± 2%) in the residual soil fraction. The silt fraction of the nonsterile vineyard soil became enriched in ⁶⁵Cu over time (Δδ⁶⁵Cu = 0.25 ± 0.07‰), whereas the clay fraction was depleted in ⁶⁵Cu (Δδ⁶⁵Cu = -0.20 ± 0.07‰). Cu isotope fractionation mirrored the Cu distribution in soil chemical fractions, suggesting that Cu stable isotopes may help to follow-up Cu ageing. In contrast, no significant Zn isotope fractionation was observed among soil experiments or over time. Overall, our study emphasizes the variability in ageing of synthetic pesticides and heavy metals co-occurring in agricultural soils and their interplay in physical and chemical fractions of the soil.

Pesticide concentrations in agricultural storm drainage inlets of a small Swiss catchment

Agricultural pesticides transported to surface waters pose a major risk for aquatic ecosystems. Modelling studies indicate that the inlets of agricultural storm drainage systems can considerably increase the connectivity of surface runoff and pesticides to surface waters. These model results have however not yet been validated with field measurements. In this study, we measured discharge and concentrations of 51 pesticides in four out of 158 storm drainage inlets of a small Swiss agricultural catchment (2.8 km²) and in the receiving stream. For this, we performed an event-triggered sampling during 19 rain events and collected plot-specific pesticide application data. Our results show that agricultural storm drainage inlets strongly influence surface runoff and pesticide transport in the study catchment. The concentrations of single pesticides in inlets amounted up to 62 µg/L. During some rain events, transport through single inlets caused more than 10% of the stream load of certain pesticides. An extrapolation to the entire catchment suggests that during selected events on average 30 to 70% of the load in the stream was transported through inlets. Pesticide applications on fields with surface runoff or spray drift potential to inlets led to increased concentrations in the corresponding inlets. Overall, this study corroborates the relevance of such inlets for pesticide transport by establishing a connectivity between fields and surface waters, and by their potential to deliver substantial pesticide loads to surface waters.

Multiple pesticides in lentic small water bodies: Exposure, ecotoxicological risk, and contamination origin

Lentic small water bodies (LSWB) are a highly valuable landscape element with important ecosystem services and benefits for humans and the environment. However, data about their pesticide contamination dynamic and the associated ecotoxicological effects are scarce. To overcome these knowledge gaps, five LSWBs located in agricultural fields in Northern Germany were studied during the spring pesticide application period (April to July 2018) and the concentrations of 94 pesticides were measured in weekly intervals. The goals of this study were to observe the trends of pesticide contamination during the application period, assess the ecotoxicity of the contamination, and assign the findings to temporal and spatial origins. Samples contained pesticide concentrations between 0.12 and 4.83 μg L^-1 as sums. High detection frequencies (81% of samples) and concentrations (max 1.2 μg L^-1) were observed for metazachlor transformation products. Contamination from multiple pesticides was detected with up to 25 compounds per sample and a maximum of 37 compounds per LSWB during the entire sampling period. High toxicities for algae and macrophytes were recorded using toxic units (TU) of -0.2 to -3.5. TUs for invertebrates were generally lower than for algae/macrophytes (-2.7 to -5.2) but were also recorded at levels with ecological impacts. Pesticide detections were separated into four categories to assign them to different temporal and spatial origins. Pesticides from the spring (5-11%) and the previous autumn (0-36%) application periods were detected in the LSWB. Some pesticides could be related to the application of the previous crop on the same field (0-39%), but most of the compounds (44-85%) were not related to the crop management in the last two years on the respective LSWB fields. The relevance of different input pathways is still unknown. Particularly, the effect of long-distance transport needs to be clarified to protect aquatic biota in LSWBs.

Fate of metal-EDTA complexes during ferrihydrite aging: Interaction of metal-EDTA and iron oxides

The widespread presence of ferrihydrite in the environment makes many contaminants including metal-EDTA complexes being adsorbed on it. However, the fate of metal-EDTA complexes during the transformation of ferrihydrite was poorly understood. Understanding the migration and speciation changes of metal-EDTA adsorbed on ferrihydrite during the transformation was helpful to predict its fate in some natural and engineering environments. In this work, the interaction of the two metal-EDTA complexes (Ni(II)-EDTA and Ca(II)-EDTA) and ferrihydrite during the 9-day transformation of ferrihydrite at different pH values was studied. The results showed that part of EDTA complexing metals changed to non-complexed metals during the ferrihydrite transformation, which was due to the fact that metal in the metal-EDTA exchanged with Fe(III) on ferrihydrite. Besides, different speciation of metal ions migrated during the transformation of ferrihydrite. Meanwhile, Fe(III)-EDTA formed in this process, and the exchange of metal in Ca(II)-EDTA with Fe(III) in ferrihydrite was faster than that of Ni(II)-EDTA. Besides, the presence of metal-EDTA affected the transformation rate of ferrihydrite under neutral and alkaline condition, and metal-EDTA accelerated the dissolution of ferrihydrite to form goethite. Therefore, ferrihydrite and metal-EDTA influenced each other during the transformation of ferrihydrite. The results of this work revealed that the process of metal-EDTA dissolving ferrihydrite not only included the dissociation of metal-EDTA, but also involved the migration of metal ions and affected the transformation of ferrihydrite.

The influence of rainfall and catchment characteristics on runoff generation in urban catchments-a case study in Hebi City of China

An in-depth understanding of the rainfall-runoff process is essential for effective stormwater management. However, the understanding of the hierarchy of rainfall characteristics in terms of their importance in influencing runoff generation is limited. This paper investigates the influence of rainfall characteristics and catchment characteristics on runoff generation in urban catchments. The outcomes showed that there are 4 dominant factors affecting runoff generation: total precipitation TP and maximum 60-min rainfall intensity MAX60 are the two top-ranked factors while average rainfall intensity RI and maximum 5-min rainfall intensity MAX5 are ranked second. Additionally, compared to the moderate rainfall regime (MR), the heavy rainfall regime (HR) tends to produce higher peak flow rates, higher total inflow per unit area, and lower runoff control effect. Note that the antecedent precipitation has a more significant effect on runoff generation and is even the dominant factor when rainstorm events with daily rainfall larger than 50 mm are not considered. The results of analyzing the influence of catchment characteristics suggest that only under HR regime conditions do the catchment characteristics have an impact on runoff generation and behave as smaller catchment areas, and higher proportions of green landscapes always lead lower peak flow rates, lower total inflows per unit area, and higher runoff control effects.

Simultaneous determination of pesticides from soils: a comparison between QuEChERS extraction and Dutch mini-Luke extraction methods

The expanding nature of the agricultural sector has fuelled the intensification of plant protection products usage, including pesticides. These pesticides may persist in soils, necessitating their accurate determination in a variety of soil types. However, due to their complex nature, the effective extraction of pesticide residues from soil matrices can present challenges to pesticide detection and quantification. This research compared two well-known extraction methods, QuEChERS and Dutch mini-Luke, by assessing their specificity, sensitivity, accuracy, precision and reproducibility in extracting seven distinct pesticides with a range of chemico-physical characteristics from Irish soils. The HPLC-UV conditions were optimised to separate the seven pesticides, and it was shown that both extraction methods successfully extracted neonicotinoids with recovery values ranging between 85 and 115%. Fluroxypyr and prothioconazole could not be efficiently extracted using QuEChERS, however, the recovery values of both the analytes ranged between 59 and 117% using Dutch mini-Luke. Furthermore, with the exception of prothioconazole using Dutch mini-Luke, both extraction methods resulted in reproducibility and precision values below or equal to 20%. Lastly, Dutch mini-Luke is noted to have a lower matrix effect than QuEChERS, except for prothioconazole. The comparison results showed that Dutch mini-Luke resulted in superior method sensitivity, better recovery, and lower matrix effect towards most investigated analytes and was the only extraction technique that successfully extracted all pesticides analysed in soil matrices.

Pesticide residues in drinking water, their potential risk to human health and removal options

The application of pesticides in agricultural and public health sectors has resulted in substantially contaminated water resources with residues in many countries. Almost no reviews have addressed pesticide residues in drinking water globally; calculated hazard indices for adults, children, and infants; or discussed the potential health risk of pesticides to the human population. The objectives of this article were to summarize advances in research related to pesticide residues in drinking water; conduct health risk assessments by estimating the daily intake of pesticide residues consumed only from drinking water by adults, children, and infants; and summarize options for pesticide removal from water systems. Approximately 113 pesticide residues were found in drinking water samples from 31 countries worldwide. There were 61, 31, and 21 insecticide, herbicide, and fungicide residues, respectively. Four residues were in toxicity class IA, 14 residues were in toxicity class IB, 55 residues were in toxicity class II, 17 residues were in toxicity class III, and 23 residues were in toxicity class IV. The calculated hazard indices (HIs) exceeded the value of one in many cases. The lowest HI value (0.0001) for children was found in Canada, and the highest HI value (30.97) was found in Egypt, suggesting a high potential health risk to adults, children, and infants. The application of advanced oxidation processes (AOPs) showed efficient removal of many pesticide classes. The combination of adsorption followed by biodegradation was shown to be an effective and efficient purification option. In conclusion, the consumption of water contaminated with pesticide residues may pose risks to human health in exposed populations.

Simple Osthole/Nanocarrier Pesticide Efficiently Controls Both Pests and Diseases Fulfilling the Need of Green Production of Strawberry

The application of botanical pesticides is a good choice in organic agriculture. However, most botanical pesticides have limitations of slow action and short persistence for pest and disease management, which constrain their further application. With the objective of exploring a green pesticide for controlling strawberry pests and diseases simultaneously, a star polymer (SPc) with a low production cost was synthesized as a pesticide nanocarrier through simple reactions. The SPc complexed with osthole quickly through electrostatic interaction and hydrophobic association, which decreased the particle size of osthole down to the nanoscale (17.66 nm). With the help of SPc, more nano-sized osthole was delivered into cytoplasm through endocytosis, leading to the enhanced cytotoxicity against insect cells. As a green botanical pesticide, the control efficacy of the osthole/SPc complex was improved against main strawberry pests (green peach aphid and two-spotted spider mite) and disease (powdery mildew), which fulfilled the need of both pest and disease management in sustainable production of strawberry. Meanwhile, the introduction of SPc not only improved plant-uptake but also decreased the residue of osthole due to the higher degradation rate. Furthermore, the application of the osthole/SPc complex exhibited no influence on the strawberry fruit quality and nontarget predators. To our knowledge, it is the first success to control plant pests and diseases simultaneously for sustainable agriculture by only one pesticidal formulation based on nanoparticle-delivered botanical pesticides.

Polluted paradise: Occurrence of pesticide residues within the urban coastal zones of Santa Cruz and Isabela (Galapagos, Ecuador)

Although pesticides are frequently used for agriculture in the Galapagos Islands (Ecuador), there are, to date, no investigations of pesticide occurrences in its coastal waters. We examined the presence of pesticide residues in the coastal waters of urban areas in two islands of the Galapagos archipelago using a repeated sampling design. Quantification was performed by solid-phase extraction, followed by chemical analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-electron capture detector (GC-ECD). The diversity and concentration of pesticide residues in Santa Cruz island were higher compared to Isabela island. In total, sixteen pesticides were detected, including three persistent organic pollutants. Carbendazim (23.93 μg·L^-1), cadusafos (4.74 μg·L^-1), DDT (2.99 μg·L^-1), diuron (1.61 μg·L^-1) and aldrin (1.55 μg·L^-1) were detected with the highest concentrations between samples. Repetitions in locations show that concentrations of pesticide residues varied considerably in space and time. Comparison with local products indicated agricultural activities on the islands as a possible source. Furthermore, evaluation through ecological risk quotients showed that the observed concentration levels of seven pesticides pose a relatively high risk for three biotic groups (i.e. algae, invertebrates and fishes). Taken together, this study provides insights into the need to regulate, monitor and assess the presence of pesticides in the islands. At a global scale, this study is moreover valuable for the many islands that are facing the same challenges.