Screening of pesticides and veterinary drugs in small streams in the European Union by liquid chromatography high resolution mass spectrometry

Development and validation of rapid screening of 192 veterinary drug residues in aquatic products using HPLC-HRMS coupled with QuEChERS

The presence of veterinary drug residues in aquatic products represents a significant challenge to food safety. The current detection methods, limited in both scope and sensitivity, underscore the urgent need for more advanced techniques. This research introduces a swift and potent screening technique using high-performance liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS) and a refined QuEChERS protocol, allowing simultaneous qualitative and semi-quantitative analysis of 192 residues. A comprehensive database, employing full scan mode and data-dependent secondary mass spectroscopy, enhances screening accuracy. The method involves efficient extraction using 90% acetonitrile, dehydration with Na2SO4, and acetic acid, followed by cleanup using dispersive solid-phase extract sorbent primary secondary amine. It is suitable for samples with varying fat content, offering detection limits ranging from 0.5 to 10 μg/kg, high recovery rates (60-120%), and low relative standard deviations (<20%). Practical application has validated its effectiveness for multi-residue screening, marking a significant advancement in food safety evaluation.

Occurrence of emerging contaminants in three river basins impacted by wastewater treatment plant effluents: Spatio-seasonal patterns and environmental risk assessment

The concern on the fate and distribution of contaminants of emerging concern (CECs) is a burning topic due to their widespread occurrence and potential harmful effects. Particularly, antibiotics have received great attention due to their implications in antimicrobial resistance occurrence. The impact of wastewater treatment plants (WWTP) is remarkable, being one of the main pathways for the introduction of CECs into aquatic systems. The combination of novel analytical methodologies and risk assessment strategies is a promising tool to find out environmentally relevant compounds posing major concerns in freshwater ecosystems impacted by those wastewater effluents. Within this context, a multi-target approach was applied in three Spanish river basins affected by different WWTP treated effluents for spatio-temporal monitoring of their chemical status. Solid phase extraction followed by ultra-high-performance liquid chromatography were used for the quantification of a large panel of compounds (n = 270), including pharmaceuticals and other consumer products, pesticides and industrial chemicals. To this end, water samples were collected in four sampling campaigns at three locations in each basin: (i) upstream from the WWTPs; (ii) WWTP effluent discharge points (effluent outfall); and (iii) downstream from the WWTPs (500 m downriver from the effluent outfall). Likewise, 24-h composite effluent samples from each of the WWTPs were provided in all sampling periods. First the occurrence and distribution of these compounds were assessed. Diverse seasonal trends were observed depending on the group of emerging compounds, though COVID-19 outbreak affected variations of certain pharmaceuticals. Detection frequencies and concentrations in effluents generally exceeded those in river samples and concentrations measured upstream WWTPs were generally low or non-quantifiable. Finally, risks associated with maximum contamination levels were evaluated using two different approaches to account for antibiotic resistance selection as well. From all studied compounds, 89 evidenced environmental risk on at least one occasion in this study.

Pesticide residues in boreal arable soils: Countrywide study of occurrence and risks

Large volumes of pesticides are applied every year to support agricultural production. The intensive use of pesticides affects soil quality and health, but soil surveys on pesticide residues are scarce, especially for northern Europe. We investigated the occurrence of 198 pesticide residues, including both banned and currently used substances in 148 field sites in Finland. Results highlight that pesticide residues are common in the agricultural soils of Finland. A least one residue was found in 82% of the soils, and of those 32% contained five or more residues. Maximum total residue concentration among the conventionally farmed soils was 3043 μg/kg, of which AMPA and glyphosate contributed the most. Pesticide residues were also found from organically farmed soils, although at 75-90% lower concentrations than in the conventionally farmed fields. Thus, despite the application rates of pesticides in Finland being generally much lower than in most parts of central and southern Europe, the total residue concentrations in the soils occurred at similar or at higher levels. We also established that AMPA and glyphosate residues in soil are significantly higher in fields with cereal dominated rotations than in grass dominated or cereal-grass rotations. However, risk analyses for individual substances indicated low ecological risk for most of the fields. Furthermore, the total ecological risk associated with the mixtures of residues was mostly low except for 21% of cereal dominated fields with medium risk. The results showed that the presence of mixtures of pesticide residues in soils is a rule rather than an exception also in boreal soils. In highly chemicalized modern agriculture, the follow-up of the residues of currently used pesticides in national and international soil monitoring programs is imperative to maintain soil quality and support sustainable environment policies.

Distribution and risk assessment of pesticide pollution in small streams adjoining paddy fields

The present investigation was planned to bridge the knowledge gap on spatiotemporal variations of pesticide pollution in small streams adjacent to paddy fields, and to visualize the associated risks in the aquatic ecosystems. We screened 106 pesticides using GCMSMS and LCMSMS from 10 small streams (n = 212, surface water samples) adjacent to paddy fields over seven months. Fifty-five pesticides were detected across different streams and months. The highest mean concentration was detected for fenobucarb (272 ng L-1), followed by thiamethoxam (199 ng L-1). The highest maximum concentration was detected for thiamethoxam ( 13,264 ng L-1), followed by triflumezopyrim ( 11,505 ng L-1). The highest detection frequency was recorded for fenobucarb (80.00%), followed by pretilachlor (79.00%). Out of the ten streams, Attabira stream had the highest mean number of pesticides detected in each sample. Maximum number of pesticides were detected in October followed by September. Pesticides namely, hexaconazole, pretilachlor, tricyclazole, fenobucarb and thiamethoxam were consistently detected across all streams. The risk assessment against the fishes, micro-invertebrates and algae were measured by risk quotient index (RQ). Twenty-five pesticides out of the detected pesticides (n = 55) had risk quotient values greater than 1. The highest RQmax values were observed in case of fenpropathrin followed by cyfluthrin-3. The highest RQmean value was observed in case of cyfluthrin, indicating its higher toxicity to fishes. The present study reveals that small streams are polluted with pesticides and there is a need to develop strategies and policy interventions in regularizing the pesticide uses for reducing the pesticide pollution in aquatic systems.

Assessing pesticide residues occurrence and risks in water systems: A Pan-European and Argentina perspective

Freshwater ecosystems face a particularly high risk of biodiversity loss compared to marine and terrestrial systems. The use of pesticides in agricultural fields is recognized as a relevant stressor for freshwater environments, exerting a negative impact worldwide on the overall status and health of the freshwater communities. In the present work, part of the Horizon 2020 funded SPRINT project, the occurrence of 193 pesticide residues was investigated in 64 small water bodies of distinct typology (creeks, streams, channels, ditches, rivers, lakes, ponds and reservoirs), located in regions with high agricultural activity in 10 European countries and in Argentina. Mixtures of pesticide residues were detected in all water bodies (20, median; 8-40 min-max). Total pesticide levels found ranged between 6.89 and 5860 ng/L, highlighting herbicides as the dominant type of pesticides. Glyphosate was the compound with the highest median concentration followed by 2,4-D and MCPA, and in a lower degree by dimethomorph, fluopicolide, prothioconazole and metolachlor(-S). Argentina was the site with the highest total pesticide concentration in water bodies followed by The Netherlands, Portugal and France. One or more pesticides exceeded the threshold values established in the European Water Framework Directive for surface water in 9 out of 11 case study sites (CSS), and the total pesticide concentration surpassed the reference value of 500 ng/L in 8 CSS. Although only 5 % (bifenthrin, dieldrin, fipronil sulfone, permethrin, and terbutryn) of the individual pesticides denoted high risk (RQ > 1), the ratios estimated for pesticide mixtures suggested potential environmental risk in the aquatic compartment studied.

Efficient dissipation of acetamiprid, metalaxyl, S-metolachlor and terbuthylazine in a full-scale free water surface constructed wetland in Bologna province, Italy: A kinetic modeling study

The study investigated the dissipation ability of a vegetated free water surface (FWS) constructed wetland (CW) in treating pesticides-contaminated agricultural runoff/drainage water in a rural area belonging to Bologna province (Italy). The experiment simulated a 0.1% pesticide agricultural water runoff/drainage event from a 12.5-ha farm by dissolving acetamiprid, metalaxyl, S-metolachlor, and terbuthylazine in 1000 L of water and pumping it into the CW. Water and sediment samples from the CW were collected for 4 months at different time intervals to determine pesticide concentrations by multiresidue extraction and chromatography-mass spectrometry analyses. In parallel, no active compounds were detected in the CW sediments during the experimental period. Pesticides dissipation in the wetland water compartment was modeled according to best data practices by fitting the data to Single First Order (SFO), First Order Multi-Compartment (FOMC) and Double First Order in Parallel (DFOP) kinetic models. SFO (except for metalaxyl), FOMC and DFOP kinetic models adequately predicted the dissipation for the four investigated molecules, with the DFOP kinetic model that better fitted the observed data. The modeled distribution of each pesticide between biomass and water in the CW highly correlated with environmental indexes as Kow and bioconcentration factor. Computed DT50 by DFOP model were 2.169, 8.019, 1.551 and 2.047 days for acetamiprid, metalaxyl, S-metolachlor, and terbuthylazine, respectively. Although the exact degradation mechanisms of each pesticide require further study, the FWS CW was found to be effective in treating pesticides-contaminated agricultural runoff/drainage water within an acceptable time. Therefore, this technology proved to be a valuable tool for mitigating pesticides runoff occurring after intense rain events.

Insights into spirotetramat-induced thyroid disruption during zebrafish (Danio rerio) larval development: An integrated approach with in vivo, in vitro, and in silico analyses

Spirotetramat (SPT), a tetronic acid-derived insecticide, is implicated in reproductive and lipid metabolism disorders, as well as developmental toxicity in fish. While these effects are documented, the precise mechanisms underlying its developmental toxicity are not fully elucidated. In this study, zebrafish embryos (2 h post-fertilization, hpf) were exposed to four concentrations of SPT (0, 60, 120, and 240 μg/L) until 21 dpf (days post-fertilization). We delved into the mechanisms by examining its potential disruption of the thyroid endocrine system, employing in vivo, in vitro, and in silico assays. The findings showed notable developmental disturbances, including reduced hatching rates, shortened body lengths, and decelerated heart rates. Additionally, there was an increase in malformations and a decline in locomotor activity. Detailed analyses revealed that SPT exposure led to elevated thyroid hormone levels, perturbed the hypothalamic-pituitary-thyroid (HPT) axis transcript levels, amplified deiodinase type I (Dio1) and deiodinase type II (Dio2) activities, and both transcriptionally and proteomically upregulated thyroid receptor beta (TRβ) in larvae. Techniques like molecular docking and surface plasmon resonance (SPR) confirmed SPT's affinity for TRβ, consistent with in vitro findings suggesting its antagonistic effect on the T3-TR complex. These insights emphasize the need for caution in using tetronic acid-derived insecticides.

Occurrence, ecological risk, and advanced removal methods of herbicides in waters: a timely review

Coastal pollution caused by the importation of agricultural herbicides is one of the main environmental problems that directly affect the coastal primary productivity and even the safety of human seafood. It is urgent to evaluate the ecological risk objectively and explore feasible removal strategies. However, existing studies focus on the runoff distribution and risk assessment of specific herbicides in specific areas, and compared with soil environment, there are few studies on remediation methods for water environment. Therefore, we systematically reviewed the current situation of herbicide pollution in global coastal waters and the dose-response relationships of various herbicides on phytoplankton and higher trophic organisms from the perspective of ecological risks. In addition, we believe that compared with the traditional single physical and chemical remediation methods, biological remediation and its combined technology are the most promising methods for herbicide pollution remediation currently. Therefore, we focus on the application prospects, challenges, and management strategies of new bioremediation systems related to biology, such as constructed wetlands, membrane bioreactor processes, and microbial co-metabolism, in order to provide more advanced methods for reducing herbicide pollution in the water environment.

Occurrence of pesticide residues in indoor dust of farmworker households across Europe and Argentina

Pesticides are widely used as plant protection products (PPPs) in farming systems to preserve crops against pests, weeds, and fungal diseases. Indoor dust can act as a chemical repository revealing occurrence of pesticides in the indoor environment at the time of sampling and the (recent) past. This in turn provides information on the exposure of humans to pesticides in their homes. In the present study, part of the Horizon 2020 funded SPRINT project, the presence of 198 pesticide residues was assessed in 128 indoor dust samples from both conventional and organic farmworker households across Europe, and in Argentina. Mixtures of pesticide residues were found in all dust samples (25-121, min-max; 75, median). Concentrations varied in a wide range (<0.01 ng/g-206 μg/g), with glyphosate and its degradation product AMPA, permethrin, cypermethrin and piperonyl butoxide found in highest levels. Regarding the type of pesticides, insecticides showed significantly higher levels than herbicides and fungicides. Indoor dust samples related to organic farms showed a significantly lower number of residues, total and individual concentrations than those related to conventional farms. Some pesticides found in indoor dust were no longer approved ones (29 %), with acute/chronic hazards to human health (32 %) and with environmental toxicity (21 %).

Daphnia magna Multigeneration Exposure to Carbendazim: Gene Transcription Responses

The world population is experiencing colossal growth and thus demand for food, leading to an increase in the use of pesticides. Persistent pesticide contamination, such as carbendazim, remains a pressing environmental concern, with potentially long-term impacts on aquatic ecosystems. In the present study, Daphnia magna was exposed to carbendazim (5 µg L-1) for 12 generations, with the aim of assessing gene transcription alterations induced by carbendazim (using a D. magna custom microarray). The results showed that carbendazim caused changes in genes involved in the response to stress, DNA replication/repair, neurotransmission, ATP production, and lipid and carbohydrate metabolism at concentrations already found in the environment. These outcomes support the results of previous studies, in which carbendazim induced genotoxic effects and reproduction impairment (increasing the number of aborted eggs with the decreasing number of neonates produced). The exposure of daphnids to carbendazim did not cause a stable change in gene transcription between generations, with more genes being differentially expressed in the F0 generation than in the F12 generation. This could show some possible daphnid acclimation after 12 generations and is aligned with previous multigenerational studies where few ecotoxicological effects at the individual and populational levels and other subcellular level effects (e.g., biochemical biomarkers) were found.

Moving past neonicotinoids and honeybees: A systematic review of existing research on other insecticides and bees

Synthetic pesticides (e.g. herbicides, fungicides and insecticides) are used widely in agriculture to protect crops from pests, weeds and disease. However, their use also comes with a range of environmental concerns. One key concern is the effect of insecticides on non-target organisms such as bees, who provide pollination services for crops and wild plants. This systematic literature review quantifies the existing research on bees and insecticides broadly, and then focuses more specifically on non-neonicotinoid insecticides and non-honeybees. We find that articles on honeybees (Apis sp.) and insecticides account for 80% of all research, with all other bees combined making up 20%. Neonicotinoids were studied in 34% of articles across all bees and were the most widely studied insecticide class for non-honeybees overall, with almost three times as many studies than the second most studied class. Of non-neonicotinoid insecticide classes and non-honeybees, the most studied were pyrethroids and organophosphates followed by carbamates, and the most widely represented bee taxa were bumblebees (Bombus), followed by leaf-cutter bees (Megachile) and mason bees (Osmia). Research has taken place across several countries, with the highest numbers of articles from Brazil and the US, and with notable gaps from countries in Asia, Africa and Oceania. Mortality was the most studied effect type, while sub-lethal effects such as on behaviour were less studied. Few studies tested how the effect of insecticides were influenced by multiple pressures, such as climate change and co-occurring pesticides (cocktail effects). As anthropogenic pressures do not occur in isolation, we suggest that future research also addresses these knowledge gaps. Given the changing global patterns in insecticide use, and the increasing inclusion of both non-honeybees and sub-lethal effects in pesticide risk assessment, there is a need for expanding research beyond its current state to ensure a strong scientific evidence base for the development of risk assessment and associated policy.

Selected neonicotinoids and associated risk for aquatic organisms

Neonicotinoids are one of the newest groups of systemic pesticides, effective on a wide range of invertebrate pests. The success of neonicotinoids can be assessed according to the amount used, for example, in the Czech Republic, which now accounts for 1/3 of the insecticide market. The European Union (EU) has a relatively interesting attitude towards neonicotinoids. Three neonicotinoid substances (imidacloprid, clothianidin and thiamethoxam) were severely restricted in 2013. In 2019, imidacloprid and clothianidin were banned, while thiamethoxam and thiacloprid were banned in 2020. In 2022, another substance, sulfoxaflor, was banned. Therefore, only two neonicotinoid substances (acetamiprid and flupyradifurone) are approved for outdoor use in the EU. Neonicotinoids enter aquatic ecosystems in many ways. In European rivers, neonicotinoids usually occur in nanograms per litre. Due to the low toxicity of neonicotinoids to standard test species, they were not expected to significantly impact the aquatic ecosystem until later studies showed that aquatic invertebrates, especially insects, are much more sensitive to neonicotinoids. In addition to the lethal effects, many studies point to sublethal impacts - reduced reproductive capacity, initiation of downstream drift of organisms, reduced ability to eat, or a change in feeding strategies. Neonicotinoids can affect individuals, populations, and entire ecosystems.

Assessment of Cold Atmospheric Pressure Plasma (CAPP) Treatment for Degradation of Antibiotic Residues in Water

The presence of antibiotic residues in water is linked to the emergence of antibiotic resistance globally and necessitates novel decontamination strategies to minimize antibiotic residue exposure in both the environment and food. A holistic assessment of cold atmospheric pressure plasma technology (CAPP) for β-lactam antibiotic residue removal is described in this study. CAPP operating parameters including plasma jet voltage, gas composition and treatment time were optimized, with highest β-lactam degradation efficiencies obtained for a helium jet operated at 6 kV. Main by-products detected indicate pH-driven peroxidation as a main mechanism of CAPP-induced decomposition of β-lactams. No in vitro hepatocytotoxicity was observed in HepG2 cells following exposure to treated samples, and E. coli exposed to CAPP-degraded β-lactams did not exhibit resistance development. In surface water, over 50% decrease in antibiotic levels was achieved after only 5 min of treatment. However, high dependence of treatment efficiency on residue concentration, pH and presence of polar macromolecules was observed.

Wide-scope screening of multi-class contaminants in seafood using a novel sample preparation (QuEChUP) procedure coupled with UHPLC-Q-TOF-MS: Application for semi-quantitation of real seafood samples

A high-resolution mass spectrometry screening method was developed and validated based on EU SANTE/11312/2021 guidelines for the analysis of 850 multi-class contaminants in commercial seafood samples. Samples were extracted using a novel sequential QuEChUP preparation method that combines the QuEChERS and QuPPe procedures. The screening detection limits (SDLs) and limits of identification (LOIs) were equal to or lower than 0.01 mg·kg^-1 for 92% and 78% of contaminants, respectively. This screening procedure was ultimately applied for a target screening analysis of 24 seafood samples. The concentrations of identified contaminants were assessed using semi-quantitative approach. Two identified contaminants, diuron and diclofenac, showed the highest estimated average concentrations: 0.076 and 0.068 mg·kg^-1 respectively in mussel samples. Suspect screening was also performed. Target and suspect screening led to the identification of mixtures of contaminants (pesticides, veterinary products, industrial chemicals and personal care products) and the assessment of their frequencies of appearance (FoA).

Spatiotemporal distribution patterns and ecological risk of multi-pesticide residues in the surface water of a typical agriculture area in China

This study systematically investigated the occurrence, spatiotemporal distribution, and ecological risk of 106 pesticides in the surface water of the Jiaodong Peninsula in China. The results show that 52 pesticides, including 21 insecticides, 10 fungicides, and 21 herbicides, were detectable in the surface water. The concentrations of target pesticides in water samples ranged from 0.42 (tebuconazole in the wet season) to 645.31 ng/L (thiamethoxam in the normal season). The two most polluting and widespread pesticides were quintozene (maximum concentration of 481.46 ng/L and detection rate of 94 %) and atrazine (maximum concentration of 465.73 ng/L and detection rate of 100 %). The total pesticide concentrations in surface water in different seasons revealed the order of dry season > wet season > normal season. Based on aquatic pesticide concentrations, their frequency of occurrence, and effect concentrations, insecticides posed higher risks to aquatic organisms and human health than either fungicides or herbicides. Total pesticide concentrations were significantly positively correlated with suspended particulate matter, dissolved organic carbon, soil pH, normalized difference vegetation index, adjacent cropland area; and were negatively associated with adjacent grassland area. The cropland area largely influences pesticide distribution in the surface water of the Jiaodong Peninsula.

Mitigating Ecotoxicity Risks of Pesticides on Ornamental Plants Based on Life Cycle Assessment

Ornamental plants such as floriculture and nurseries, have become increasingly popular, but their growth relies heavily on the use of many different types of pesticides. The widespread and inefficient use of these pesticides causes environmental pollution and damage to non-target organisms. Despite these impacts, there has been little research conducted on potential agrochemical pollution in the ornamental plant industry. To address this gap, a life cycle assessment (LCA) was conducted to evaluate the pesticide-related freshwater ecotoxicity impact of the US ornamental plant industry in comparison to that of major field crops. The study analyzed 195 pesticide active ingredients used in 15 major ornamental plant and four field crops. Results showed that the freshwater ecotoxicity per area (PAF m³ d/ha) of ornamental plants was significantly higher than that of field crops due to the high pesticide intensity (kg/ha) and ecotoxicity of insecticides and fungicides used in floriculture and nurseries. To mitigate environmental stress, minimizing the use of highly toxic pesticides is recommended. A ban on low-dose, high-toxicity pesticides could reduce pesticide-driven ecotoxicity by 34% and 49% for floriculture and nursery plants, respectively. This study is among the first to quantify the pesticide-driven ecotoxicity impacts of horticultural ornamental plants and proposes feasible ways to reduce these impacts, thus making the world more sustainable while still preserving its beauty.

Effect of florasulam on oxidative damage and apoptosis in larvae and adult zebrafish (Danio rerio)

Florasulam is widely used for weed control in wheat fields due to its high activity and low dosage. Previous studies on florasulam have focused on soil microbial and residue determination, however, its ecotoxicity to aquatic organisms is unclear. The toxicity of florasulam was evaluated in larvae (120 h) and adult (14 and 28 d) zebrafish. After florasulam (0.1 and 1 μg L^-1) exposure, reactive oxygen species levels in larvae and adult zebrafish significantly increased and antioxidant system was activated. Florasulam induced lipid peroxidation in larvae and adult zebrafish. Florasulam did not cause DNA damage to larvae but caused DNA damage to adult zebrafish. Changes in caspase 3/8/9 genes indicated that apoptosis was induced in larvae but inhibited in adult zebrafish. By calculating integrated biomarker response, caspase 3 and malondialdehyde could be used as early warning indicators of florasulam effect on larvae and adult zebrafish, respectively. The higher the exposure concentration, the greater the toxicity of florasulam to larvae and adult zebrafish. Increasing exposure time resulted in higher toxicity to adult zebrafish. Florasulam has different toxicity at larvae and adult zebrafish. In future studies to investigate florasulam toxicity to zebrafish, different zebrafish life stages (larvae and adult) need to be studied.

Combined effects of high temperature and pesticide mixture exposure on free-swimming behaviors and hepatic cytochrome P450 1A expression in goldfish, Carassius auratus

The synergy between multiple compounds and other stressors, including heat, creates volatility and greater unpredictability than standard single-chemical toxicity testing, especially in the case of pesticides and metabolites which might contain several noxious ingredients resulting in adverse ecological effects. To address this, the aim of this study was to examine the dose- and time-dependent effects of low- and high-dose pesticide mixture (metalachlor, linuron, isoproturon, tebucanazole, aclonifen, atrazine, pendimethalin, azinphos-methyl) and heat stress co-exposure (22°C control/32°C treatment for 4-week) on free-swimming behaviors and cumulative actionless time (CAT) of goldfish. Behavioral analysis showed a dose- and time-dependent decrease in distance swam, as well as a subsequent increase in CAT. Vertical and horizontal spatial behavioral use were affected under heat and pesticides co-exposure conditions. In 3- and 4-week(s) exposure groups, horizontal spatial behavioral use demonstrated elevated time spent in the lower third of the aquarium. Similarly, during 3- and 4-week(s) exposure (32°C control and 32°C high doses) vertical spatial behavioral use was found to increase time spent in the outermost edges of the aquarium. In all treatment groups, the final condition factor (KM) showed significant attenuation when compared to the initial KM. However, there was an unclear relationship between heat/pesticide co-exposure and growth most notably in 32°C high-dose groups. In addition, the expression of hepatic cytochrome P450 1A mRNA was significantly higher in pesticide-exposed groups. Taken together, data demonstrated that co-exposure with low- or high-dose pesticide mixture and heat stress significantly impacted natural swimming patterns, which over time might result in the broader population and ecological effects.

Multi-characteristic toxicity of enantioselective chiral fungicide tebuconazole to a model organism Mediterranean mussel Mytilus galloprovincialis Lamarck, 1819 (Bivalve: Mytilidae)

The survey of available scientific literature shows a lack of data on the chronic effects of tebuconazole (TEB) on non-target aquatic organisms. Therefore, this study evaluates toxicity (10 and 20 days) of two considered concentrations 2 ng/L (E1) and 2 μg/L (E2) of TEB to bioindicator species Mytilus galloprovincialis. To this end, the TEB concentrations measured in soft mussel tissues showed a time-dependent increasing trend. The viability of haemocyte and digestive gland (DG) cells was higher than 95 % during the experiment. However, DG cells lost the ability to regulate their volume in both groups after 20-d. The E1 treatment increased Cl^- and Na⁺ levels, and E2 decreased Na⁺ levels in the haemolymph. In addition, levels of superoxide dismutase (SOD) activity and oxidatively modified protein (OMP) increased after 10- and 20-d in both treatments. Histopathological findings showed abnormalities in the E2, e.g., haemocyte infiltration, hypertrophy, and hyperplasia in gills and DG. This study reveals the potential risks of TEB usage in the model organism M. galloprovincialis, primarily via bioaccumulation of TEB in food web links, and improves knowledge about its comprehensive toxicity.

Sublethal biochemical, behavioral, and physiological toxicity of extremely low dose of bendiocarb insecticide in Periplaneta americana (Blattodea: Blattidae)

Insecticides are dedicated to impair the insect organisms, but also have an impact on other, non-target organisms, including humans. In this way, they became important risk factor for disturbance of physiological homeostasis and can be involved in the development of diseases or in deterioration of existing conditions. The influence of sublethal doses of various insecticides on vertebrates' and invertebrates' organisms has been previously observed. In this paper, we have evaluated the impact of exposure to extremely low dose of neurotoxin, bendiocarb (0.1 nM), a commonly used carbamate insecticide on a model organism in neurobiology-Periplaneta americana. The assessment was performed on all levels of animal organism from molecular (oxidative stress parameters: phosphorylation level of proteins, cAMP level, protein kinase A and C levels, and octopamine) to physiological (heart beat and gas exchange tests) and behavioral (motor skills assay, grooming test). Exposure to such a low level of bendiocarb did not cause direct paralysis of insects, but changed their grooming behavior, decreased heart rate, and increased gas exchange. We also observed the increased parameters of oxidative stress as well as stressogenic response to 0.1 nM bendiocarb exposure. Exposure to a trace amount of bendiocarb also increased sensitivity to effective doses of the same insecticide, thus acts as preconditioning. These results force us to reconsider the possible risk from frequent/continuous exposure to traces of pesticide residues in the environment to human health.

Occurrence of organic pollutants in the River Itchen and River Test-two chalk streams in Southern England, UK

The River Itchen and River Test, two chalk streams in Southern England, are sites of special scientific interest. These ecosystems face a number of environmental pressures from anthropogenic inputs of organic pollutants. Hence, we investigated the occurrence of these chemicals within the two catchments. Spot water samples (1 L) were collected at nineteen sites along the catchment on two occasions (March and June 2019). Samples were extracted (HLB-L sorbent disks) and analysed using high-resolution liquid chromatography-quadrupole-time-of-flight mass spectrometry and gas chromatography-mass spectrometry. Compounds were identified against commercially available databases. Using this approach, we found 115 pharmaceutical and personal care products, 81 plant protection products and 35 industrial chemicals. This complex mixture of pollutants covered a range of physico-chemical properties and included priority substances in the EU Water Framework Directive or currently on the third Watch List. Both rivers had similar chemical profiles for both months. Herbicides and fungicides were dominant in the spring, whereas insecticides occurred more frequently in the summer. Point discharges from wastewater treatment plants were the main source of pharmaceutical and personal care products. Agricultural activities were the main contributor to the presence of plant protection products. The impact of these organic chemicals on the ecology, particularly on macroinvertebrate biodiversity, is unknown and warrants further investigation. Our suspect screening approach could guide future toxicological investigations to assess the environmental impacts of these diverse chemicals.

The screening of emerging micropollutants in wastewater in Sol Plaatje Municipality, Northern Cape, South Africa

Although pollutants pose environmental and human health risks, the majority are not routinely monitored and regulated. Organic pollutants emanate from a variety of sources, and can be classified depending on their chemistry and environmental fate. Classification of pollutants is important because it informs fate processes and apposite removal technologies. The occurrence of emerging contaminants (ECs) in water bodies is a source of environmental and human health concern globally. Despite being widely reported, data on the occurrence of ECs in South Africa are scarce. Specifically, ECS in wastewater in the Northern Cape in South Africa are understudied. In this study, various ECs were screened in water samples collected from three wastewater treatment plants (WWTPs) in the province. The ECs were detected using liquid chromatography coupled to high resolution Orbitrap mass spectrometry following Oasis HLB solid-phase extraction. The main findings were: (1) there is a wide variety of ECs in the WWTPs, (2) physico-chemical properties such as pH, total dissolved solids, conductivity, and dissolved organic content showed reduced values in the outlet compared to the inlet which confirms the presence of less contaminants in the treated wastewater, (3) specific ultraviolet absorbance of less than 2 was observed in the WWTPs samples, suggesting the presence of natural organic matter (NOM) that is predominantly non-humic in nature, (4) most of the ECs were recalcitrant to the treatment processes, (5) pesticides, recreational drugs, and analgesics constitute a significant proportion of pollutants in wastewater, and (6) NOM removal ranged between 35 and 90%. Consequently, a comprehensive database of ECs in wastewater in Sol Plaatje Municipality was created. Since the detected ECs pose ecotoxicological risks, there is a need to monitor and quantify ECs in WWTPs. These data are useful in selecting suitable monitoring and control strategies at WWTPs.

Simultaneous screening and analysis of 155 veterinary drugs in livestock foods using ultra-high performance liquid chromatography tandem quadrupole linear-ion-trap mass spectrometry

Veterinary drugs are widely used to improve the health and growth of livestock. The supervision of these residues is necessary to ensure food safety. A high-throughput method based on Oasis PRiME HLB with solid phase extraction for simultaneous qualitative and quantitative analysis of 155 veterinary drugs in livestock foods was developed by the ultra-high performance liquid chromatography tandem quadrupole linear-ion-trap mass spectrometry (UHPLC-QTRAP-MS). The limits of detection and quantification ranged from 0.5 μg/kg to 5 μg/kg and 2 μg/kg to 20 μg/kg, respectively. For over 85% of the analytes, the recoveries were between 60% and 120%. The positive simulated samples perfectly matched with a purity fit value over 70% from the self-built library. The screening results of UHPLC-QTRAP-MS were almost consistent with UHPLC tandem quadrupole-exactive orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap/MS). The evaluated UHPLC-QTRAP-MS method was powerful and reliable for the screening and quantification of veterinary drugs in real samples.

Toxic effects of fludioxonil on the growth, photosynthetic activity, oxidative stress, cell morphology, apoptosis, and metabolism of Chlorella vulgaris

Fludioxonil is widely used in the control of crop diseases because of its broad spectrum and high activity, but its presence is now common in waterways proximate to treated areas. This study examined the toxic effects and mechanisms of fludioxonil on the microalgal taxa Chlorella vulgaris. The results showed that fludioxonil limited the growth of C. vulgaris and the median inhibitory concentration at 96 h was 1.87 mg/L. Concentrations of 0.75 and 3 mg/L fludioxonil reduced the content of photosynthetic pigments in algal cells to different degrees. Fludioxonil induced oxidative damage by altering C. vulgaris antioxidant enzyme activities and increasing reactive oxygen species levels. Fludioxonil at 0.75 mg/L significantly increased the activity of antioxidant enzymes. The highest level of activity was 1.60 times that of the control group. Both fludioxonil treatment groups significantly increased ROS levels, with the highest increase being 1.90 times that of the control group. Transmission electron microscope showed that treatment with 3 mg/L fludioxonil for 96 h disrupted cell integrity and changed cell morphology, and flow cytometer analysis showed that fludioxonil induced apoptosis. Changes in endogenous substances indicated that fludioxonil negatively affects C. vulgaris via altered energy metabolism, biosynthesis of amino acids, and unsaturated fatty acids. This study elucidates the effects of fludioxonil on microalgae and the biological mechanisms of its toxicity, providing insights into the importance of the proper management of this fungicide.

Production and Selection of Antibody–Antigen Pairs for the Development of Immunoenzyme Assay and Lateral Flow Immunoassay Methods for Carbofuran and Its Analogues

To produce a sensitive monoclonal antibody (mAb) for the simultaneous detection of carbofuran, benfuracarb, carbosulfan and 3-hydroxy-carbofuran, 2,3-dihydro-2,2-dimethyl-7-benzofuranmethanamine (DDB) was conjugated to bovine serum albumin (BSA) to prepare the immunogen DDB-BSA and mice were immunized. Coating antigens were prepared by conjugating DDB and 5-methoxy-2,3-dihydrobenzofuran-3-acetic acid (MDA) to BSA and ovalbumin (OVA), respectively. Furthermore, the effect of different antibody–antigen pairs on the sensitivity of ELISA and LFIA methods for the detection of carbofuran was investigated. After the immunization, a high-affinity mAb 13C8 was obtained. The ability of the coating antigen to compete with carbofuran for binding antibodies was found to be significantly different between ELISA and LFIA methods. With the antibody–antigen pair 13C8-MDA-OVA, the IC₅₀ values of the ELISA and QD-LFIA methods for carbofuran were 0.18 ng/mL and 0.67 ng/mL, respectively. The cross-reactivity (CR) values of the two methods for benfuracarb, carbosulfan and 3-hydroxy-carbofuran ranged from 72.0% to 83.7%, while, for other carbamate pesticides, the CR values were less than 1%. The spiked recoveries of carbofuran in vegetables by the QD-LFIA method were 83–111%, with a coefficient of variation below 10%, and the test results of the actual samples were consistent with the HPLC-MS method. Overall, this study provides key materials for the development of immunoassays for carbofuran and its analogues, and the antibody–antigen pair selection strategy established in this study provides useful insights for the development of sensitive immunoassays for other compounds.

Environmental and human health at risk - Scenarios to achieve the Farm to Fork 50% pesticide reduction goals

The recently released Farm to Fork Strategy of the European Union sets, for the first time, pesticide reduction goals at the EU level: 50% reduction in overall use and risk of chemical pesticides and a 50% use reduction of more hazardous pesticides. However, there is little guidance provided as to how to achieve these targets. In this study, we compiled the characteristics of all 230 EU-approved, synthetic, open-field use active substances (AS) used as herbicides, fungicides and insecticides, and explored the potential of seven Farm to Fork-inspired pesticide use reduction scenarios to achieve the 50% reduction goals. The pesticide reduction scenarios were based on recommended AS application rates, pesticide type, soil persistence, presence on the candidate for substitution list, and hazard to humans and ecosystems. All 230 AS have been found to cause negative effects on humans or ecosystems depending on exposure levels. This is found despite the incomplete hazard profiles of several AS. 'No data available' situations are often observed for the same endpoints and specific organisms. The results of the scenarios indicate that only severe pesticide use restrictions, such as allowing only low-hazard substances, will result in the targeted 50% use and risk reductions. Over half of the 230 AS considered are top use or top hazard substances, however, the reduction actions depend on the still to be defined EC priority areas and action plans, also for other recent and related strategies. Broader scenario implications (on productivity, biodiversity or economy) and the response of farmers to the pesticide use restrictions should be explored in those plans to define effective actions. Our results emphasize the need for a re-evaluation of the approved AS and of their representative uses, and the call for open access to AS, crop and region-specific use data to refine scenarios and assess effective reductions.

Adsorptive and photocatalytic remediation of hazardous organic chemical pollutants in aqueous medium: A review

The provision of clean water is still a major challenge in developing parts of the world, as emphasized by the United Nation Sustainable Development Goals (SDG 6), and has remained a subject of extensive research globally. Advancements in science and industry have resulted in a massive surge in the amount of industrial chemicals produced within the last few decades. Persistent and emerging organic pollutants are detected in aquatic environments, and conventional wastewater treatment plants have ineffectively handled these trace, bioaccumulative and toxic compounds. Therefore, we have conducted an extensive bibliometric analysis of different materials utilized to combat organic pollutants via adsorption and photocatalysis. The classes of pollutants, material synthesis, mechanisms of interaction, merits, and challenges were comprehensively discussed. The paper highlights the advantages of various materials used in the removal of hazardous pollutants from wastewater with activated carbon having the highest adsorption capacity. Dyes, pharmaceuticals, endocrine-disrupting chemicals, pesticides and other recalcitrant organic pollutants have been successfully removed at high degradation efficiencies through the photocatalytic process. The photocatalytic degradation and adsorption processes were compared by considering factors such as cost, efficiency, ease of application and reusability. This review will be good resource material for water treatment professionals/scientists, who may be interested in adsorptive and photocatalytic remediation of organic chemicals pollutants.

A novel calibration strategy based on isotopic distribution for high-throughput quantitative analysis of pesticides and veterinary drugs using LC-HRMS

Preparation of calibration curves is a critical step for large-scale quantification. However, this procedure is time-consuming, labor intensive. Herein, a novel isotopologue multipoint calibration (IMC) strategy, was proposed and demonstrated for the simultaneous quantitation of 120 pesticides and 83 veterinary drugs in surface water samples using Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS). In this strategy, the natural isotopic distribution was used to generate external calibration curves, eliminating the need of analyst's adjustment and many sets of chemical standard solutions required in external calibration curves. Additionally, this strategy was comprehensively validated, and the results indicated this strategy had better performance in both accuracy and precision, fully meeting the requirements for the quantitative analysis. Interestingly, for the samples with high concentration beyond the upper limit of quantitation, the IMC strategy could avoid samples dilution by monitoring the less abundant isotopic channels. Furthermore, the IMC method was successfully applied in the surface water samples collected from Anhui province, China. Among which, sulfamethoxazole and imidacoprid were the main contributors. In conclusion, we present a promising LC-HRMS strategy for the accurate quantitation of small molecules, which has a potential application in food and environmental analysis.

The combination of chemical, structural, and functional indicators to evaluate the anthropogenic impacts on agricultural stream ecosystems

Freshwater contamination by pesticides in agricultural landscapes is of increasing concern worldwide, with strong pesticide impacts on biodiversity, ecosystem functions, and ultimately human health (drinking water, fishing). In addition, the excessively large number of substances, as well as their low - and temporally variable - concentrations in water, make the chemical monitoring by grab sampling very demanding and not fully representative of the actual contamination. Tools that integrate temporal variations and that are ecologically relevant are clearly needed to improve the monitoring of freshwater contamination and assess its biological effects. Here, we studied pesticide contamination and its biological impacts in 10 stream sections (sites) belonging to 3 agricultural catchments in France. In each site, we deployed a combination of pesticide integrative samplers, biocenotic indicators based on benthic macroinvertebrates, and functional indicators based on leaf litter decomposition and associated fungal communities. The 3 approaches largely proved complementary: structural and functional indicators did not respond equally to different agricultural impacts such as pesticide contamination (as revealed by integrative samplers), nutrients, or oxygen depletion. Combining chemical, structural, and functional indicators thus seems an excellent strategy to provide a comprehensive picture of agricultural impacts on stream ecosystems.

Computer-aided profiling of a unique broad-specific antibody and its application to an ultrasensitive fluoroimmunoassay for five N-methyl carbamate pesticides

Pollution of N-methyl carbamate (NMC) pesticides is threatening the non-target organisms' survival. Thus, broad-specific antibodies and class-selective immunoassays are demanding for multiple NMCs determination. In this study, we employed a molecular docking-based virtual screening strategy to fast profile antibody spectrum, based on a designed chemical pool containing 17 compounds. A monoclonal antibody (mAb)-6G against carbofuran was used as the objective. The recombinant full-length IgG was successfully expressed to validate the antibody sequences for homology modeling. After docking, we manually categorized the antibody-chemical binding strength into three groups. Non-competitive surface plasmon resonance (SPR) demonstrated the mAb-6G affinitive binding toward five NMCs (carbofuran, isoprocarb, propoxur, carbaryl and carbosulfan), which were classified into strong and moderate binding categories. Antibody binding properties were confirmed again by ic-ELISA and lateral flow immunochromatographic strip. Subsequently, an ultrasensitive indirect competitive fluoromicrosphere-based immunoassay (ic-FMIA) was established with the IC₅₀ (half-maximal inhibitory concentration) values of 0.08-3.37 ng/mL. This portable assay presented a 30-230-fold improved sensitivity than traditional ic-ELISA and was applied in European surface water analysis. Overall, our work provides an efficient platform integrating in-silico and experimental methodologies to accelerate the characterization of hapten-specific antibody binding properties and the development of high-sensitive immunoassays for multi-pollutants monitoring.

Background ions into exclusion list: A new strategy to enhance the efficiency of DDA data collection for high-throughput screening of chemical contaminations in food

Foods contaminated with hazardous compounds, could pose potential risks for human health. To date, there is still a big challenge in accurate identification. In this study, a novel data-dependent acquisition (DDA) approach, based on a combination of inclusion list and exclusion list, was proposed to acquire more effective MS/MS spectra. This strategy was successfully applied in a large-scale screening survey to detect 50 mycotoxins in oats, 155 veterinary drugs in dairy milk, and 200 pesticides in tomatoes. Compared with traditional acquisition modes, this new strategy has higher detection rate, particularly at ultra-low concentration by eliminating background influence, thereby generating the MS/MS spectra for more potential hazardous materials instead of matrix interference. Additionally, the obtained MS/MS spectra are simpler and more likely to be traced back than DIA. Moreover, this new strategy would be more comprehensively applied in food safety monitoring with the improvement of HRMS and post-acquisition techniques.

Subchronic exposure to Epoxiconazole induced-heart damage in male Wistar rats

Epoxiconazole is a worldwide fungicide used to control fungal diseases. Although to its hazardous effects in non-target species, little information is available in the literature to show the cardiotoxic effects of EPX in male rats. Thus, our investigation aimed to assess the outcomes of EPX exposure on some biochemical parameters, the generation of oxidative stress, DNA fragmentation and histopathological alterations in the heart tissue. EPX was administered orally at doses of 8, 24, 40 and 56 mg/kg body weight, representing, respectively NOEL (No observed effect level), NOEL× 3, NOEL× 5 and NOEL× 7 for 28 consecutive days in male Wistar rats. Our results show that EPX induced a significant decrease of cardiac acetylcholinesterase, an increase of biochemical markers, such as creatinine phosphokinase (CPK) and a perturbation of the lipid profile. Furthermore, EPX caused diverse histological modifications in the myocardium, including congestion of cardiac blood vessels, cytoplasmic vacuolization, leucocytic infiltration and hemorrhage. Indeed, we have shown that EPX induces increase of lipid peroxidation, protein oxidation levels and DNA damage. On the other hand, we have found an increase of the antioxidant enzymes activity such as catalase (CAT) and superoxide dismutase (SOD) activities. The glutathione peroxidase and glutathione S tranferase initially enhanced at the doses of 8, 24, and 40 mg/kg b.w. and then decreased at the dose of 56 mg/kg b.w. In conclusion, our work has shown that EPX causes cardiotoxic effects by altering redox status and damaging heart tissue.

Pharmaceuticals in water and sediment of small streams under the pressure of urbanization: Concentrations, interactions, and risks

Small streams are crucial but vulnerable elements of ecological networks. To better understand the occurrence of pharmaceutically active compounds (PhACs) in streams, this study focused on the occurrence, distribution, and environmental risk of 111 PhACs and 7 trace elements based on a total of 141 water and sediment samples from small streams located in the urbanizing region of Budapest, Hungary. Eighty-one PhACs were detected in the aqueous phase, whereas sixty-two compounds were detected in the sediment. Carbamazepine (CBZ) was the most frequently identified PhAC in water, and was found in 91.5% of all samples. However, the highest concentrations were measured for lamotrigine (344.8 μg·L^-1) and caffeine (221.4 μg·L^-1). Lidocaine was the most frequently occurring PhAC in sediment (73.8%), but the maximum concentrations were detected for CBZ (395.9 ng·g^-1) and tiapride (187.7 ng·g^-1). In both water and sediment, more PhACs were found downstream of the wastewater treatment plants (WWTPs) than in the samples not affected by treated wastewater, even though no relationship was observed between the total amount of treated wastewater and the number of detected PhACs. The PhAC concentrations were also independent of the distance from the WWTP effluents. PhAC-polluted samples were detected upstream of the WWTPs, thereby suggesting the relevance of diffuse emissions in addition to WWTP outlets. The most frequently detected PhACs in the sediment were usually also present in the water samples collected at the same place and time. The varying concentrations of PhACs and the fluctuating water-sediment properties resulted in a lack of correlation between the general chemical properties and the concentrations of PhACs, which makes it difficult to predict PhAC contamination and risks in urbanized small streams. The environmental risk assessment indicated that diclofenac had the highest risk in the sampling area.

Suspect, non-target and target screening of pharmaceuticals and personal care products (PPCPs) in a drinking water system

Drinking water quality and safety are very important in protecting human health. Chemical contaminants in drinking water system have become an increasing concern. Our knowledge about what chemicals are present in drinking water is still limited. Here we screened chemicals of emerging concern in a conventional drinking water system based on suspect, non-target screening and target analysis, and assessed their variations in different seasons and different treatment units. Overall, 720 chemicals were identified with HRMS databases from the suspect and non-target screening and 48 chemicals in five categories were further confirmed with the high confidence level, with predominance of pharmaceuticals and personal care products (PPCPs) and pesticides. Four compounds are newly found in aquatic environment with no literature or chemical occurrence data record. Temporal variations and variable removals were observed for these chemicals in the system. Target analysis of 110 PPCPs showed detection of 21, 19 and 22 compounds in the drinking water treatment plant with a concentration range of 0.11-844 ng/L in the three seasons, but only 8, 9 and 15 compounds detected in tap water (0.16-32.5 ng/L). The variations of the detected chemicals were less obvious in tap water, with most having concentrations below 2 ng/L. The results indicated efficient removal for most PPCPs in the drinking water system. The findings from this study demonstrated the strong capability of combined non-target screening and target analysis in identifying and assessing various organic chemicals in drinking water system.

Pivotal role of water molecules in the photodegradation of pymetrozine: New insights for developing green pesticides

Photodegradation of the insecticide pymetrozine (PYM) was studied on surface of wax films, and in aqueous and nonaqueous phase. The half-life of PYM on the wax surface was approximately 250 times longer than in water. Scavenging experiments, laser flash photolysis, and spectra analysis indicated the first singlet excited state of PYM (S1 *_PYM) to be the most important photoinduced species initiating the photodegradation. Quantum chemistry calculations identified significant molecular torsion and changes in the structure C-CN-N of S1 *_PYM, and the absolute charges of the CN atoms increased and the bond strength weakened. Free energy surface analysis, and O¹⁸ labeling experiments further confirmed that the mechanism was two-step photoinduced hydrolysis. The first step is the hydrolysis of S1 *_PYM at CN upon reaction with 2-3 water molecules (one H₂O molecule as the catalyst). The second step is an intramolecular hydrogen transfer coupled with the cleavage of C-N bond and formation of two cyclic products. During the interactions, water molecules experience catalytic activation by transferring protons, while there is a negligible solvent effect. Clarifying the detailed photodegradation mechanisms of PYM is beneficial for the development of green pesticides that are photostable and effective on leaf surfaces, and photolabile and detoxified in the aquatic environment.

New-generation pesticides are prevalent in California's Central Coast streams

Pesticides are widely recognized as important biological stressors in streams, especially in heavily developed urban and agricultural areas like the Central California Coast region. We assessed occurrence and potential toxicity of pesticides in small streams in the region using two analytical methods: a broad-spectrum (223 compounds) method in use since 2012 and a newly developed method for 30 additional new-generation fungicides and insecticides. At least one pesticide compound was identified in 83 of the 85 streams sampled. About one-half (48%) of the 253 pesticides measured were detected at least once and 27 were detected in 10% or more of samples. Three of the top 4, and 6 of the top 10 most frequently detected compounds (chlorantraniliprole, dinotefuran, boscalid, thiamethoxam, clothianidin and the fluopicolide degradate 2,6-dichlorobenzamide) were analyzed by the new method. Pesticide mixtures were common, with two or more pesticide compounds detected in 81% of samples and 10 or more in 32% of samples. The pesticide count at a site was relatively consistent over the 6-week study. Four sites with mixed land-use in the lower basin (<5 km from the sampling site) tended to have the highest pesticide counts and the highest concentrations. Potential toxicity (assessed by comparison to benchmarks) to invertebrates was much more common than potential toxicity to fish or plants and was associated with a wide array of insecticides. The common occurrence of new-generation pesticides highlights the need to continuously update analytical methods to keep pace with changing pesticide use for a fuller assessment of pesticide occurrence and effects on the environment.

Revisiting pesticide pollution: The case of fluorinated pesticides

Fluorinated pesticides acquired a significant market share in the agrochemical sector due to the surge of new fluoroorganic ingredients approved in the last two decades. This growing trend has not been accompanied by a comprehensive scientific and regulatory framework entailing all their potential negative impacts for the environment, especially when considering the hazardous properties that may result from the incorporation of fluorine into organic molecules. This review aims to address the safe/hazardous dichotomy associated with fluorinated pesticides by providing an updated outlook on their relevancy in the agrochemical sector and how it leads to their role as environmental pollutants. Specifically, the environmental fate and distribution of these pesticides in the ecosystems is discussed, while also analysing their potential to act as toxic substances for non-target organisms.

Multi-parameter risk assessment of forty-one selected substances with endocrine disruptive properties in surface waters worldwide

The increasing use of substances with endocrine disruptive properties (EDs) not only impacts aquatic organisms but can also have a direct negative effect on human health. In this comprehensive worldwide review, we collected ecotoxicology and concentration data observed in surface water for 53 high-potency EDs and performed a risk assessment. The compounds were selected from the EU watchlist of priority substances, expanded with new compounds of emerging concern (total 41), where quantifiable data were available for the past three years (2018-2020). The risk quotients ranged from <0.01 for 22 substances to 1974 for tamoxifen. The frequency of samples in which the predicted no-effect concentrations were exceeded also varied, from 1.8% to 92.7%. By using the comprehensive multi-parameter risk assessment in our study, the most current to date, we determined that tamoxifen, imidacloprid, clothianidin, four bisphenols (BPA, BPF, BPS, and BPAF), PFOA, amoxicillin, and three steroid hormones (estriol, estrone, and cyproterone) pose significant risks in the environment. Comparing two structurally very similar bisphenols, BPA and BPB, suggested that the risk from BPB is currently underestimated by at least four orders of magnitude due to the lack of ecotoxicological data availability. The methodological limitations encountered suggest that a standardized methodology for data selection and assessment is necessary, highlighting the fact that some substances are currently under-represented in the field of ecotoxicological research. A new prioritization system is therefore presented, which provides a potential basis for new substances to be included in environmental monitoring lists.

Environmental monitoring study of pesticide contamination in Denmark through honey bee colonies using APIStrip-based sampling

Due to their extensive use in both agricultural and non-agricultural applications, pesticides are a major source of environmental contamination. Honey bee colonies are proven sentinels of these and other contaminants, as they come into contact with them during their foraging activities. However, active sampling strategies involve a negative impact on these organisms and, in most cases, the need of analyzing multiple heterogeneous matrices. Conversely, the APIStrip-based passive sampling is innocuous for the bees and allows for long-term monitorings using the same colony. The versatility of the sorbent Tenax, included in the APIStrip composition, ensures that comprehensive information regarding the contaminants inside the beehive will be obtained in one single matrix. In the present study, 180 APIStrips were placed in nine apiaries distributed in Denmark throughout a six-month sampling period (10 subsequent samplings, April to September 2020). Seventy-five pesticide residues were detected (out of a 428-pesticide scope), boscalid and azoxystrobin being the most frequently detected compounds. There were significant variations in the findings of the sampling sites in terms of number of detections, pesticide diversity and average concentration. A relative indicator of the potential risk of pesticide exposure for the honey bees was calculated for each sampling site. The evolution of pesticide detections over the sampling periods, as well as the individual tendencies of selected pesticides, is herein described. The findings of this large-scale monitoring were compared to the ones obtained in a previous Danish, APIStrip-based pilot monitoring program in 2019. Samples of honey and wax were also analyzed and compared to the APIStrip findings.

Collection of human and environmental data on pesticide use in Europe and Argentina: Field study protocol for the SPRINT project

Current farm systems rely on the use of Plant Protection Products (PPP) to secure high productivity and control threats to the quality of the crops. However, PPP use may have considerable impacts on human health and the environment. A study protocol is presented aiming to determine the occurrence and levels of PPP residues in plants (crops), animals (livestock), humans and other non-target species (ecosystem representatives) for exposure modelling and impact assessment. To achieve this, we designed a cross-sectional study to compare conventional and organic farm systems across Europe. Environmental and biological samples were/are being/will be collected during the 2021 growing season, at 10 case study sites in Europe covering a range of climate zones and crops. An additional study site in Argentina will inform the impact of PPP use on growing soybean which is an important European protein-source in animal feed. We will study the impact of PPP mixtures using an integrated risk assessment methodology. The fate of PPP in environmental media (soil, water and air) and in the homes of farmers will be monitored. This will be complemented by biomonitoring to estimate PPP uptake by humans and farm animals (cow, goat, sheep and chicken), and by collection of samples from non-target species (earthworms, fish, aquatic and terrestrial macroinvertebrates, bats, and farm cats). We will use data on PPP residues in environmental and biological matrices to estimate exposures by modelling. These exposure estimates together with health and toxicity data will be used to predict the impact of PPP use on environment, plant, animal and human health. The outcome of this study will then be integrated with socio-economic information leading to an overall assessment used to identify transition pathways towards more sustainable plant protection and inform decision makers, practitioners and other stakeholders regarding farming practices and land use policy.

Experimental evidence for neonicotinoid driven decline in aquatic emerging insects

Survey data show a large-scale decline in insects. This global decline is often linked to human actions in intensive agricultural areas. To investigate whether this decline has a causal relationship with neonicotinoid insecticides, we performed an outdoor experiment with representative surface water concentrations of the neonicotinoid thiacloprid. We exposed naturally formed aquatic communities to increasing neonicotinoid concentrations and monitored insect emergence during a 3-mo period. We show that increasing neonicotinoid concentrations strongly decreased the abundance and biomass of five major insect orders that together comprised >99% of the 55,574 collected insects as well as the diversity of the most species-rich freshwater family, thus showing a causal relation between insect decline and neonicotinoids.

There is an ongoing unprecedented loss in insects, both in terms of richness and biomass. The usage of pesticides, especially neonicotinoid insecticides, has been widely suggested to be a contributor to this decline. However, the risks of neonicotinoids to natural insect populations have remained largely unknown due to a lack of field-realistic experiments. Here, we used an outdoor experiment to determine effects of field-realistic concentrations of the commonly applied neonicotinoid thiacloprid on the emergence of naturally assembled aquatic insect populations. Following application, all major orders of emerging aquatic insects (Coleoptera, Diptera, Ephemeroptera, Odonata, and Trichoptera) declined strongly in both abundance and biomass. At the highest concentration (10 µg/L), emergence of most orders was nearly absent. Diversity of the most species-rich family, Chironomidae, decreased by 50% at more commonly observed concentrations (1 µg/L) and was generally reduced to a single species at the highest concentration. Our experimental findings thereby showcase a causal link of neonicotinoids and the ongoing insect decline. Given the urgency of the insect decline, our results highlight the need to reconsider the mass usage of neonicotinoids to preserve freshwater insects as well as the life and services depending on them.

Combining Culture-Dependent and Independent Approaches for the Optimization of Epoxiconazole and Fludioxonil-Degrading Bacterial Consortia

Epoxiconazole (EPO) and fludioxonil (FLU) are two widely used fluorinated pesticides known to be highly persistent and with high ecotoxicological potential, turning them into pollutants of concern. This work aimed to optimize two degrading bacterial consortia, previously obtained from an agricultural soil through enrichment with EPO and FLU, by characterizing the contribution of their corresponding bacterial isolates to the biodegradation of these pesticides using both culture-dependent and independent methodologies. Results showed that a co-culture of the strains Hydrogenophaga eletricum 5AE and Methylobacillus sp. 8AE was the most efficient in biodegrading EPO, being able to defluorinate ca. 80% of this pesticide in 28 days. This catabolic performance is likely the result of a commensalistic cooperation, in which H. eletricum may be the defluorinating strain and Methylobacillus sp. may assume an accessory, yet pivotal, catabolic role. Furthermore, 16S rRNA metabarcoding analysis revealed that these strains represent a minority in their original consortium, showing that the biodegradation of EPO can be driven by less abundant phylotypes in the community. On the other hand, none of the tested combinations of bacterial strains showed potential to biodegrade FLU, indicating that the key degrading strains were not successfully isolated from the original enrichment culture. Overall, this work shows, for the first time, the direct involvement of two bacterial species, namely H. eletricum and Methylobacillus sp., in the biodegradation of EPO, while also offering insight on how they might cooperate to accomplish this process. Moreover, the importance of adequate culture-dependent approaches in the engineering of microbial consortia for bioremediation purposes is also emphasized.

Atlas of the microbial degradation of fluorinated pesticides

Fluorine-based agrochemicals have been benchmarked as the golden standard in pesticide development, prompting their widespread use in agriculture. As a result, fluorinated pesticides can now be found in the environment, entailing serious ecological implications due to their harmfulness and persistence. Microbial degradation might be an option to mitigate these impacts, though environmental microorganisms are not expected to easily cope with these fluoroaromatics due to their recalcitrance. Here, we provide an outlook on the microbial metabolism of fluorinated pesticides by analyzing the degradation pathways and biochemical processes involved, while also highlighting the central role of enzymatic defluorination in their productive metabolism. Finally, the potential contribution of these microbial processes for the dissipation of fluorinated pesticides from the environment is also discussed.

Occurrence, human health, and ecotoxicological risk assessment of pesticides in surface waters of the River Nile's Rosetta Branch, Egypt

In Egypt, the shortage of freshwater resources and their pollution constitutes a growing concern. Therefore, the objectives of this study were to (i) monitor the occurrence and spatiotemporal variations of 100 pesticides in surface water samples collected monthly (from July 2018 to June 2019) from El-Rahawy, Sabal, and Tala sampling sites along the Rosetta branch of the River Nile in Egypt, (ii) identify potential non-carcinogenic health risks for the local people through the lifetime consumption of contaminated drinking water, and (iii) perform an ecological risk assessment of aquatic organisms upon exposure to pesticides detected in surface waters based on the risk quotients (RQs) method. Of the 100 pesticides analyzed, 22 belonging to 11 chemical families were detected, and 75.5% of surface water samples were contaminated with one or more pesticide residues. The most frequently detected pesticide was malathion (57%), followed by chlorpyrifos (54%), atrazine (23%), and carbendazim (20%). Spatial distribution showed that the El-Rahawy site had the highest pesticide load (38.47 μg/L), and Sabal had the lowest (16.29 μg/L). Temporal variations revealed that the highest total pesticide concentrations were detected in summer (27.98 μg/L) compared to spring (23.16 μg/L), winter (19.18 μg/L), and autumn (11.85 μg/L). For non-carcinogenic risks of pesticides detected in surface water, the target hazard quotient (THQ) values were less than one. This implies that there is no potential human risk from exposure to drinking water at the sites under study. However, 13 pesticides presented high-risk quotients (RQ > 1), posing potential ecological risks to aquatic organisms.

Seasonal and spatial dynamics of selected pesticides and nutrients in a small lake catchment - Implications for agile monitoring strategies

Intensive anthropogenic pressure such as high inputs of nutrients and pesticides severely threaten most European water bodies. Small catchments ≤10 km² are not monitored under the Water Framework Directive but play an important role in freshwater ecosystems. The high complexity in seasonal and spatial dynamics require more than a one-size-fits-all approach in water quality monitoring. Often located in rural areas with a high agricultural activity, small catchments often carry high amounts of nutrients, pesticides and their transformation products affecting drinking water resources. With a low-cost approach of a monthly sampling campaign over the course of one year combined with meaningful indicators for potential pollution sources within the catchment this study could elucidate catchment dynamics and two hotspots for pesticides and nutrients. Two different groups of pesticides were observed (I) pesticides on long-term use which were applied in high amounts over the last decades (e.g., chloridazon and its transformation products) and (II) pesticides on short-term use, newly introduced into the market. Especially transformation products of pesticides from group (I) together with nitrate showed a steady release from two fields into the receiving water bodies over the year, probably being stored in the soil layers over the years of application slowly leaching out. Pesticides from group (II) showed a strong seasonality, released from another hotspot area probably due to run-off shortly after application. Streamlining this knowledge into targeted measures and an agile monitoring strategy for the respective catchments may allow a sustainable improvement of water quality and a better ecosystem protection.

Endocrine disrupting potential of veterinary drugs by in vitro stably transfected human androgen receptor transcriptional activation assays

We describe the androgen receptor (AR) agonistic/antagonistic effects of 140 veterinary drugs regulated in Republic of Korea, by setting maximum residue limits. It was conducted using two in vitro test guidelines of the Organization for Economic Cooperation and Development (OECD)-the AR-EcoScreen AR transactivation (TA) assay and the 22Rv1/MMTV_GR-KO AR TA assay. These were performed alongside the AR binding affinity assay to confirm whether their AR agonistic/antagonistic effects are based on the binding affinity to AR. Prior to conducting the AR TA assay, the proficiency test was passed the proficiency performance criterion for the AR agonist and AR antagonist assays. Among the veterinary drugs tested, four veterinary drugs (dexamethasone, trenbolone, altrenogest, and nandrolone) and six veterinary drugs (cymiazole, dexamethasone, zeranol, phenothiazine, bromopropylate, and isoeugenol) were determined as AR agonist and AR antagonist, respectively in both in vitro AR TA assays. Zeranol exhibited weak AR agonistic effects with a PC₁₀ value only in the 22Rv1/MMTV_GR-KO AR TA assay. Regarding changing the AR agonistic/antagonistic effects through metabolism, the AR antagonistic activities of zeranol, phenothiazine, and isoeugenol decreased significantly in the presence of phase I + II enzymes. These data indicate that various veterinary drugs could have the potential to disrupt AR-mediated human endocrine system. Furthermore, this is the first report providing information on AR agonistic/antagonistic effects of veterinary drugs using in vitro OECD AR TA assays.

Occurrence of pesticides and their transformation products in headwater streams: Contamination status and effect of ponds on contaminant concentrations

In France, more than 90% of monitored watercourses are contaminated with pesticides. This high contamination level increases at the head of agricultural watersheds, where dilution capacities are low and transport from treated lands is direct. Ponds, numerous around headwater streams, could provide additional protection against pesticide pollution. Because of their long hydraulic residence time and large water volumes, they mitigate pesticide concentrations between upstream and downstream rivers. However, pesticide transformation products may also be responsible for the degradation of environments, owing to their presence at high concentrations and their persistence, but related data are scarce, particularly because of their high level of molecular diversity. We first reported on the state of water contamination in agricultural headwater streams, based on high frequency water sampling. Analysis of 67 molecules (HPLC-ESI-MS/MS) showed pesticides and pesticide transformation product mixtures of up to 29 different compounds in one sample. Regardless of the sampling location, transformation products represented at least 50% of the detected compounds. Then, we demonstrated the capacity of a pond to reduce contaminant concentrations in downstream rivers for 90% of the detected compounds. Upstream from this pond, environmental quality or ecotoxicological standards were exceeded during sampling, with pesticide and transformation product sum concentrations of up to 27 μg/L. Downstream from the study pond, few exceedances were observed, with a maximum total concentration of 2.2 μg/L, reflecting significant water quality improvement.

Passive sampling with suspect screening of polar pesticides and multivariate analysis in river catchments: Informing environmental risk assessments and designing future monitoring programmes

Pollution of surface water by polar pesticides is a major environmental risk, particularly in river catchments where potable water supplies are abstracted. In these cases, there is a need to understand pesticide sources, occurrence and fate. Hence, we developed a novel strategy to improve water quality management at the catchment scale using passive sampling coupled to suspect screening and multivariate analysis. Chemcatcher® passive sampling devices were deployed (14 days) over a 12 month period at eight sites (including a water supply works abstraction site) in the Western Rother, a river catchment in South East England. Sample extracts (n = 197) were analysed using high-resolution liquid chromatography-quadrupole-time-of-flight mass spectrometry and compounds identified against a commercially available database. A total of 128 pesticides from different classes were found. Statistical analysis of the qualitative screening data was used to identify clusters of pesticides with similar spatiotemporal pollution patterns. This enabled pesticide sources and fate to be identified. At the water supply works abstraction site, spot sampling and passive sampling were found to be complementary, however, the passive sampling method in conjunction with suspect screening detected 50 pesticides missed by spot sampling combined with targeted analysis. Geospatial data describing pesticide application rates was found to be poorly correlated to their detection frequency using the Chemcatcher®. Our analysis prioritised 61 pesticides for inclusion in a future water quality risk assessment at the abstraction site. It was also possible to design a seasonal monitoring programme to effectively characterise the spatiotemporal pesticide profiles within the catchment. A work flow of how to incorporate passive sampling coupled to suspect screening into existing regulatory monitoring is proposed. Our novel approach will enable water quality managers to target the mitigation (non-engineered actions) of pesticide pollution within the catchment and hence, to better inform drinking water treatment processes and save on operational costs.

Small streams-large concentrations? Pesticide monitoring in small agricultural streams in Germany during dry weather and rainfall

Few studies have examined the exposure of small streams (< 30 km² catchment size) to agriculturally used pesticides, compared to large rivers. A total of 105 sites in 103 small agricultural streams were investigated for 76 pesticides (insecticides, herbicides, fungicides) and 32 pesticide metabolites in spring and summer over two years (2018 and 2019) during dry weather and rainfall using event-driven sampling. The median total concentration of the 76 pesticides was 0.18 µg/L, with 9 pesticides per sample on average (n = 815). This is significantly higher than monitoring data for larger streams, reflecting the close proximity to agricultural fields and the limited dilution by non-agricultural waters. The frequency of detection of all pesticides correlated with sales quantity and half-lives in water. Terbuthylazine, MCPA, boscalid, and tebuconazole showed the highest median concentrations. The median of the total concentration of the 32 metabolites exceeded the pesticide concentration by more than an order of magnitude. During dry weather, the median total concentration of the 76 pesticides was 0.07 µg/L, with 5 pesticides per sample on average. Rainfall events increased the median total pesticide concentration by a factor of 10 (to 0.7 µg/L), and the average number of pesticides per sample to 14 (with up to 41 in single samples). The concentration increase was particularly strong for 2,4-D, MCPA, terbuthylazine, and nicosulfuron (75 percentile). Metabolite concentrations were generally less responsive to rainfall, except for those of terbuthylazine, flufenacet, metamitron, and prothioconazole. The frequent and widespread exceedance of the regulatory acceptable concentrations (RAC) of the 76 pesticides during both, dry weather and rainfall, suggests that current plant protection product authorization and risk mitigation methods are not sufficient to protect small streams.