Water pollution by pesticides used in agriculture is currently a major concern both in Spain and in Europe as a whole, prompting the need to evaluate water quality and ecological risk in areas of intensive agriculture. This study involved monitoring pesticide residues and certain degradation products in surface and ground waters of the Denomination of Origin (DO) Jumilla vineyard area in Spain. Sixty-nine pesticides were selected and evaluated at twenty-one sampling points using a multi-residue analytical method, based on solid-phase extraction (SPE) and analysis by liquid chromatography coupled with mass spectrometry (LC-MS), providing reliable results. Twenty-six compounds from those selected were detected in the samples analyzed (eleven insecticides including one degradation product, nine herbicides, and six fungicides) and fifteen of them were found in concentrations over 0.1 μg L⁻¹ (upper threshold established by the EU for pesticides detected in waters for human consumption). Indoxacarb was present in more than 70% of the samples, being the most frequently detected compound in water samples. Some pesticides were ubiquitous in all the water samples. Ecotoxicological risk indicators, toxic units (TUs) and risk quotients (RQs), for algae, Daphnia magna and fish were calculated to estimate the environmental risk of the presence of pesticides in waters. The compounds with the highest risk were the herbicides pendimethalin, with RQ values > 1 for the three aquatic organisms, and diflufenican, posing a high risk for algae and fish, and the insecticide chlorpyrifos, with a high risk for Daphnia magna and fish. The ∑TUi determined for water at each sampling point posed only a high risk for the three aquatic organisms in a sample. These results are important for considering the selection of pesticides with less environmental risk in intensive agricultural areas.

Pendimethalin (PDM) is a dinitroaniline crop pesticide that is extensively utilized worldwide. However, the reproductive toxicity and cellular mechanisms of PDM have not been identified. Therefore, we elucidated the adverse effects of PDM on the reproductive system using mouse testicular Leydig and Sertoli cells (TM3 and TM4 cells, respectively). Our results demonstrated that PDM suppressed the viability and proliferation of TM3 and TM4 cells. Additionally, PDM induced cytosolic calcium upregulation and permeabilization of mitochondrial membrane potential in both TM3 and TM4 cells. We also verified that PDM activates the endoplasmic reticulum (ER) stress pathway and autophagy. Furthermore, we confirmed that activation of ER stress and autophagy were blocked by 2-aminoethoxydiphenyl borate (2-APB) treatment. Finally, we confirmed PDM-induced cell cycle arrest and apoptosis in TM3 and TM4 cells. Thus, we first demonstrated that PDM impedes the survival of testis cells, and further, their function.

Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Our study measured dermal uptake of pesticides of varying hydrophobicity (logKow) in frogs. Amphibians were indirectly exposed to one of five pesticide active ingredients through contact with contaminated soil: imidacloprid (logKow = 0.57), atrazine (logKow = 2.5), triadimefon (logKow = 3.0), fipronil (logKow = 4.11) or pendimethalin (logKow = 5.18). All amphibians had measurable body burdens at the end of the exposure in concentrations ranging from 0.019 to 14.562 μg/g across the pesticides tested. Atrazine produced the greatest body burdens and bioconcentration factors, but fipronil was more permeable to amphibian skin when application rate was considered. Soil partition coefficient and water solubility were much better predictors of pesticide body burden, bioconcentration factor, and skin permeability than logKow. Dermal uptake data can be used to improve risk estimates of pesticide exposure among amphibians as non-target organisms.

Considering that pesticides have been used in Europe for over 70 years, a system for monitoring pesticide residues in EU soils and their effects on soil health is long overdue. In an attempt to address this problem, we tested 340 EU agricultural topsoil samples for multiple pesticide residues. These samples originated from 4 representative EU case study sites (CSS), which covered 3 countries and four of the main EU crops: vegetable and orange production in Spain (S–V and S–O, respectively), grape production in Portugal (P-G), and potato production in the Netherlands (N–P). Soil samples were collected between 2015 and 2018 after harvest or before the start of the growing season, depending on the CSS. Conventional and organic farming results were compared in S–V, S–O and N–P. Soils from conventional farms presented mostly mixtures of pesticide residues, with a maximum of 16 residues/sample. Soils from organic farms had significantly fewer residues, with a maximum of 5 residues/sample. The residues with the highest frequency of detection and the highest content in soil were herbicides: glyphosate and its main metabolite AMPA (P-G, N–P, S–O), and pendimethalin (S–V). Total residue content in soil reached values of 0.8 mg kg⁻¹ for S–V, 2 mg kg⁻¹ for S–O and N–P, and 12 mg kg⁻¹ for P-G. Organic soils presented 70–90% lower residue concentrations than the corresponding conventional soils. There is a severe knowledge gap concerning the effects of the accumulated and complex mixtures of pesticide residues found in soil on soil biota and soil health. Safety benchmarks should be defined and introduced into (soil) legislation as soon as possible. Furthermore, the process of transitioning to organic farming should take into consideration the residue mixtures at the conversion time and their residence time in soil.

The efficiency of two common Mediterranean agroforestry systems, a potato-poplar and a maize-poplar, was assessed with respect to the uptake of nutrients and pesticides in an experimental plot located in Attica, Greece, during the cultivating period of 2016. Soil samples were collected on a monthly basis at different soil horizons and varying distance from the tree row. The monitored substances included all nitrogen ions (NO₃⁻-N, NO₂⁻-N, NH₄⁺-N), phosphates (PO₄³⁻-P), potassium (K⁺), the insecticide chlorpyrifos, as well as the herbicides s-metolachlor, pendimethalin, and its metabolite M455H001. Experiments for the potato-poplar system exhibited reductions of more than 86% for K⁺, 90% for NO₃⁻-N, 92% for NH₄⁺-N, 85% for NO₂⁻-N, and up to 100% for PO₄³⁻-P. Accordingly, for the maize-poplar system, reductions were more than 73% for K⁺, at least 77% for NO₃⁻-N, approximately 77% for NO₂⁻-N, 97% for NH₄⁺-N, and up to 100% for PO₄³⁻-P. Regarding the examined pesticides, all substances reached more than 61.5% and up to 100% disappearance in the closest to the tree row points compared to the control points, thus also exhibiting the potential for tree uptake of the excess pesticides. As such, it was demonstrated that agroforestry alley cropping systems may act as a technique for pollution abatement, since tree roots that extend below the crops can uptake the excess of agrochemicals that would otherwise enter groundwater via leaching or surface water via runoff.

The loss of pendimethalin, a selective herbicide, was determined in runoff water from loamy soil plots of various surface slopes cultivated with tobacco, over a period of 193 days. Conditions were selected to simulate agricultural practices employed in the Mediterranean region. The surface slopes of plots were 0%, 2.5%, 5%, 7.5%, and 10% and both cultivated and uncultivated (control) areas were simultaneously monitored. The cumulative losses of pendimethalin in surface runoff, as percentage of the initial applied active ingredient, were 0.067% for tilled and 0.098% for untilled soil of 10% slope, while for the plots of 0% slope they were ten times lower, 0.006% and 0.009% respectively. The maximum concentrations in runoff water reached 15.87 μg L⁻¹ and were detected after the second run off event. The dissipation in top soil was studied for a period of 129 days. The half-lives that were calculated using first order kinetics ranged from 23 to 27.2 days in non-cropped soil and from 22.3 to 26.2 in tobacco plots.

In this study, we examined the dose-dependent effects of an environmentally relevant pesticide cocktail (metalachlor, linuron, isoproturon, tebucanazole, aclonifen, atrazine, pendimethalin, and azinphos-methyl) and temperature change (22 vs. 32 °C for 4-week exposure) on Na⁺/K⁺-ATPase, 3-nitrotyrosine protein (NTP), dinitrophenyl protein (DNP), catalase (CAT), and superoxide dismutase (SOD) expressions in gills of goldfish (Carassius auratus). Histopathological analysis showed widespread damage to gill in elevated temperature (32 °C) and pesticide co-exposure groups, including fusion of secondary lamellae, club-shaped primary lamellae, rupture of epithelial layer, loss of normal architecture, and hemorrhaging. Immunohistochemical and qRT-PCR analyses showed significant decreases in Na⁺/K⁺-ATPase protein and mRNA expressions in gills exposed to higher temperature and pesticides; however, combined exposure to heat and pesticides significantly increases NTP, DNP, CAT, and SOD expressions. In situ TUNEL assay revealed elevated levels of apoptotic cells in response to combined exposure. Collectively, our results suggest the combined effects of heat and pesticide stress cause cellular damage, upregulate oxidative/nitrative stress biomarkers, and increase apoptotic cells, downregulate Na⁺/K⁺-ATPase expression in gills. This provides new evidence for oxidant/antioxidant-dependent mechanisms for downregulation of Na⁺/K⁺-ATPase expression in gills during combined exposure.

This paper describes prototypes of an on-site early warning water quality monitoring system (EWWQMS) for pesticide quantification in natural waters by fluorescence and absorbance. As many pesticides are not naturally fluorescent, this EWWQMS uses UV irradiation to transform these compounds into highly fluorescent photoproducts and obtain sufficient sensitivity. To obtain a better specificity, the system uses four UV LEDs at different wavelengths to excite the fluorescent photoproducts. For pesticides that are not sensitive to photoconversion, the EWWQMS prototypes also use UV absorption for their quantification, thus offering a wider application range. A first system uses a diode array spectrometer for detection. A second system uses a higher resolution spectrometer and an intensified CCD camera detection to increase sensitivity. Analytical applications were conducted for the determination of fipronil, acetamipride, cyprodinil, trifluraline and pendimethaline in water using both the EWWQMS prototypes. The analytical performances of these new systems are good compared with other photo-induced fluorescence methods already published. Limits of detection without pre-concentration are in the range of 0.2 to 3 ng mL⁻¹ and the recovery values range from 95 to 108%. These results show that the EWWQMS prototypes can be used as an alert system to protect industrial plants from pesticide contaminations that exceed the capabilities of their cleaning processes.

Regulators need a reliable, precise and easy to use tool for predicting the occurrence of pesticides in drain water and catchments in agricultural areas. Occurrence depends on a wide range of substance and site specific factors and this study presents a simple model built on the results from simulations of a detailed model system that does not neglect or omit any of these factors. A drainage dominated sub-catchment (0.03 km²) of the Lillebaek catchment (4.4 km²) on Funen, Denmark, represented by the catchment model MIKE SHE is considered. Detailed analyses have been made with respect to geological and hydrodynamic conditions as well as measurements of pesticide concentrations in ground and surface waters. Maximum concentrations in drain water, the time for reaching this concentration and the time interval for exceeding the limit value have been derived empirically from MIKE SHE simulations using degradation rates and sorption coefficients values for 37 pesticides included in the Danish PATE database. The relatively hydrophilic bentazon and hydrophobic pendimethalin are used as model pesticides for illustration. A simple tool applicable for a wide range of pesticides has thus been designed based on detailed analyses of a limited number of pesticides. The user requirements are degradation rates, sorption coefficients, application rates and regulatory limit values for the pesticides of interest.

The purpose of this study was to clarify the kinetic bioaccumulation potential of herbicides in the earthworm, Pheretima spp., the most common earthworms throughout Asia, and Eisenia spp., litter-feeding earthworms included in the test species recommended by the Organization for Economic Co-operation and Development. The kinetic bioaccumulation factors of trifluralin and pendimethalin were estimated from an uptake test for 10 or 12 days and from an elimination test for 10 days. The time required to reach a steady state following herbicide exposure was 7 days for both herbicides in Eisenia spp. and 1 day in Pheretima spp. The uptake rate constant (g-soil/g-worm/day) and elimination rate constant (per day) for trifluralin were 2.1 and 0.23 in Eisenia spp. and 0.42 and 0.45 in Pheretima spp., respectively, and those for pendimethalin were 1.5 and 0.26 in Eisenia spp. and 0.27 and 1.0 in Pheretima spp., respectively. Kinetic bioaccumulation factors of both herbicides were relatively close to bioaccumulation factors in steady state and were higher in Eisenia spp. (8.9 for trifluralin and 5.7 for pendimethalin) than in Pheretima spp. (0.95 and 0.26). These results demonstrated that the herbicide bioaccumulation risk is lower for Pheretima spp. than for Eisenia spp. because of the lower uptake rate and higher elimination rate in Pheretima spp.