Pesticide transport from seed dressings toward subsurface tile drains is still poorly understood. We monitored the neonicotinoid insecticides imidacloprid and thiamethoxam from sugar beet seed ...dressings in flow-proportional drainage water samples, together with spray applications of bromide and the herbicide S-metolachlor in spring and the fungicides epoxiconazole and kresoxim-methyl in summer. Event-driven, high first concentration maxima up to 2830 and 1290 ng/L for thiamethoxam and imidacloprid, respectively, were followed by an extended period of tailing and suggested preferential flow. Nevertheless, mass recoveries declined in agreement with the degradation and sorption properties collated in the groundwater ubiquity score, following the order bromide (4.9%), thiamethoxam (1.2%), imidacloprid (0.48%), kresoxim-methyl acid (0.17%), S-metolachlor (0.032%), epoxiconazole (0.013%), and kresoxim-methyl (0.003%), and indicated increased leaching from seed dressings compared to spray applications. Measured concentrations and mass recoveries indicate that subsurface tile drains contribute to surface water contamination with neonicotinoids from seed dressings.
An approach to identifying persistent organic contaminants in the environment was developed and executed for Switzerland as an example of an industrialized country. First, samples were screened with ...an in-house list using liquid chromatography high-resolution mass spectrometry (LC-HRMS/MS) and gas chromatography tandem mass spectrometry (GC–MS/MS) in 13 samples from the Swiss National Soil Monitoring Network and three sediment cores of an urban and agricultural contaminated lake. To capture a broader range of organic contaminants, the analysis was extended with a suspect screening analysis by LC-HRMS/MS of >500 halogenated compounds obtained from a Swiss database that includes industrial and household chemicals identified, by means of fugacity modeling, as persistent substances in the selected matrices. In total, the confirmation of 96 compounds with an overlap of 34 in soil and sediment was achieved. The identified compounds consist generally of esters, tertiary amines, trifluoromethyls, organophosphates, azoles and aromatic azines, with azoles and triazines being the most common groups. Newly identified compounds include transformation products, pharmaceuticals such as the flukicide niclofolan, the antimicrobial cloflucarban, and the fungicide mandipropamid. The results indicate that agricultural and urban soils as well as sediments impacted by agriculture and wastewater treatment plants (WWTPs) are the most contaminated sites. The plausibility of this outcome confirms the combination of chemical inventory, modeling of partitioning and persistence, and HRMS-based screening as a successful approach to shed light on less frequently or not yet investigated environmental contaminants and emphasizes the need for more soil and sediment monitoring in the future.
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•> 500 halogenated compounds were screened in soils and sediments•The applied approach resulted in the confirmation of 96 compounds•Soils and sediments are long-term reservoirs of persistent contaminants•Agriculture and wastewater impacted sites were the most contaminated sites•Azoles and triazines are the most common groups detected
To assess the occurrence of
toxins in wheat in Switzerland, an eight-year survey was conducted by analysing a total of 686 harvest samples from growers using LC-MS/MS. Between 2007 and 2010, 527 ...samples were obtained from 17 cantons. Between 2011 and 2014, 159 samples were collected from the canton Berne. The most frequent toxins detected were deoxynivalenol (DON), zearalenone (ZEA) and nivalenol (NIV). The overall mean DON content in all samples was 607 µg/kg, and 11% exceeded the European limit for unprocessed cereals for foodstuffs (1250 µg/kg). For ZEA (mean 39 µg/kg), 7% exceeded the respective limit (100 µg/kg), and the mean content of NIV (no limit established) was 15 µg/kg. Between the years, the ratio of mycotoxin-contaminated samples ranged between 52% and 98% for DON, 9% and 43% for ZEA and 0% and 49% for NIV. The yearly mean contents varied substantially between 68 and 1310 µg/kg for DON, 5 and 56 µg/kg for ZEA and 6 and 29 µg/kg for NIV. The geographic origin showed a significant effect on DON and ZEA contamination, but was inconsistent between the years. This study has shown that the majority of Swiss-produced wheat is, in terms of
toxins, fit for human consumption and feed purposes. Nevertheless, depending on the year, high toxin contents can be expected, an issue that growers, cereal collection centres and the food industry have to deal with to ensure food and feed safety.
The chemo-thermal oxidation method at 375°C (CTO-375) has been widely used to quantify black carbon (BC) in sediments. In the present study, CTO-375 was tested and adapted for application to soil, ...accounting for some matrix specific properties like high organic carbon (≤39%) and carbonate (≤37%) content. Average recoveries of standard reference material SRM-2975 ranged from 25 to 86% for nine representative Swiss and Indian samples, which is similar to literature data for sediments. The adapted method was applied to selected samples of the Swiss soil monitoring network (NABO). BC content exhibited different patterns in three soil profiles while contribution of BC to TOC was found maximum below the topsoil at all three sites, however at different depths (60–130cm). Six different NABO sites exhibited largely constant BC concentrations over the last 25 years, with short-term (6 months) prevailing over long-term (5 years) temporal fluctuations.
► The CTO-375 method was adapted and validated for BC analysis in soils. ► Method validation figures of merit proofed satisfactory. ► Application is shown with soil cores and topsoil temporal variability. ► BC content can be elevated in subsurface soils. ► BC contents in surface soils were largely constant over the last 25 years.
Although widely used also for soils, the chemo-thermal oxidation method at 375°C to quantify black carbon has never been properly validated for this matrix before.
Hyperspectral imaging with enhanced darkfield microscopy (HSI-M) possesses unique advantages in its simplicity and non-invasiveness. In consideration of the urgent need for profound knowledge on the ...behavior and effects of engineered nanoparticles (NPs), here, we determined the capability of HSI-M for examining cellular uptake of different metal-based NPs, including nanosized metals (silver and gold, both citrate stabilized), metal oxides (copper oxide and titanium dioxide), and CdSe/ZnS core/shell quantum dots at subtoxic concentrations. Specifically, we demonstrated that HSI-M can be used to detect and semi-quantify these NPs in the ciliated protozoan Tetrahymena thermophila as a model aquatic organism. Detection and semi-quantification were achieved on the basis of spectral libraries for the NPs suspended in extracellular substances secreted by this single-celled organism, accounting for matrix effects. HSI-M was able to differentiate between NP types, provided that spectral profiles were significantly different from each other. This difference, in turn, depended upon NP type, size, agglomeration status, and position relative to the focal plane. As an exception among the NPs analyzed in this study, titanium dioxide NPs showed spectral similarities compared to cell material of unexposed control cells, leading to false positives. High biological variability resulted in highly variable uptake of NPs in cells of the same sample as well as between different exposures. We therefore encourage the development of techniques able to reduce the currently long analysis times that still hamper the acquisition of statistically strong data sets. Overall, this study demonstrates the potential and challenges of HSI-M in monitoring cellular uptake of synthetic NPs.
Phytotoxins are produced in plants including agricultural crops. Lupins and other plants of the Fabaceae family produce toxic alkaloids. These alkaloids have been studied in food and feed, however, ...the environmental fate of alkaloids produced by cultivated lupins is largely unknown. Therefore, we conducted an agricultural field experiment to investigate the occurrence of indole and quinolizidine alkaloids in lupin plant tissues, soil, soil pore water and in drainage water. During the field experiment, alkaloids were regularly quantified (median concentrations) in lupin (13–8.7 × 103 ng/g dry weight (dw)), and topsoils at depth 0–5 cm (0.1–10 ng/g dw), and depth 15–30 cm (0.2–8.5 ng/g dw), soil pore water (0.2–7.5 ng/L) and drainage water samples (0.4–18 ng/L). Lupanine was the dominant alkaloid in all collected samples. Cumulative amounts of alkaloids emitted via drainage water were around 0.1–11 mg/ha for individual alkaloids over one growing season. The total cumulative amount of alkaloid in drainage water was 14 mg/ha, which is a very small amount compared to the mass of alkaloid in the lupin biomass (11 kg/ha) and soil (0.02 kg/ha). Nearly half of the alkaloids were exported in the drainage water during high flow events, indicating that alkaloids transport preferentially via macropores. These findings indicate that drainage from lupin cultivated areas contribute to surface water contamination. The environmental and ecotoxicological relevance of alkaloids as newly identified aquatic micropollutants in areas with agricultural activities have yet to be assessed.
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Animal manure has been used to manage soil fertility since the dawn of agriculture. It provides plant nutrients and improves soil fertility. In the last decades, animal husbandry has been ...significantly expanded globally. Its economics were optimized via the (international) trade of feed, resulting in a surplus of animal manure in areas with intensive livestock farming. Potentially toxic elements (PTEs), pathogenic microorganisms, antibiotic residues, biocides, and other micropollutants in manure threaten animal, human, and environmental health. Hence, manure application in crop fields is increasingly restricted, especially in hotspot regions with intensive livestock activities. Furthermore, ammonia volatilization and greenhouse gas (GHG) emissions during manure storage, field application, and decomposition contribute to air pollution and climate change. Conventional manure management scenarios such as composting and anaerobic digestion partially improve the system but cannot guarantee to eliminate sanitary and contamination risks and only marginally reducing its climate burden. Hence, this review discusses the potential of pyrolysis, the thermochemical conversion under oxygen‐limited conditions as an alternative treatment for animal manure providing energy and biochar. Manure pyrolysis reduces the bioavailability of PTEs, eliminates pathogenic microorganisms and organic micropollutants, and reduces GHG emissions. Pyrolysis also results in the loss of nitrogen, which can be minimized by pretreatment, that is, after removing soluble nitrogen fraction of manure, for example, by digestion and stripping of ammonia–nitrogen or liquid–solid separation. However, conclusions on the effect of manure pyrolysis on crop yield and fertilization efficiencies are hampered by a lack of nutrient mass balances based on livestock unit equivalent comparisons of manure and manure biochar applications. Hence, it is essential to design and conduct experiments in more practically relevant scenarios and depict the observations based on the amount of manure used to produce a certain amount of biochar.
Animal manure, which has been used for centuries to improve soil fertility, poses risks to human, animal, and environmental health due to the increased global expansion of animal husbandry. Conventional manure management methods have limitations in addressing these risks, but pyrolysis, a thermochemical conversion process, shows promise as an alternative treatment. It can reduce the impact of potentially toxic elements, eliminate pathogens and pollutants, and lower emissions, although more research is needed to determine its impact on crop yield and fertilization efficiency. The image was created with BioRender.com.
Ecotoxicity of silver nanoparticles on plankton organisms: a review Kalantzi, Ioanna; Mylona, Kyriaki; Toncelli, Claudio ...
Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology,
03/2019, Volume:
21, Issue:
3
Journal Article
Engineered silver nanoparticles (Ag-NPs) are ubiquitous in many commercial products due to their antibacterial and antifungal properties. Due to the different properties of NPs from their homolog ...bulk materials, the inevitable leaching of nanosilver from commercial products into the aquatic environment is raising concern about possible effects on aquatic organisms. This review aims at elucidating the inherent ecotoxicity of Ag-NPs for planktonic organisms that produce and transfer energy in the food web and play a key role in nutrient recycling. The current knowledge was gathered through laboratory studies on planktonic organisms, such as bacteria and algae. However, it has already been proven for other pollutants that the ecotoxicological response is strikingly different when simulating more realistic environmental conditions, as in the microcosm and mesocosm studies. Abiotic and biotic factors strongly contribute to altering the toxicity of Ag-NPs and of their released silver ions. The dilemma of the nano or ion effects of Ag-NP toxicity is hereby debated. As a general outlook, we observe that most of the studies were carried out at concentrations much higher than would ever be expected in the environment, and over time periods much shorter which would be typical for the environment. Furthermore, most of the research was focused on freshwater ecosystems and little information exists about the marine environment. It seems that Ag-NPs are less toxic than silver ions. Moreover, the Trojan Horse effect of Ag-NPs in the presence of other pollutants is poorly investigated. This review highlights these research gaps and recommends further research on the Ag-NP ecotoxicity in aquatic environments under more realistic conditions in large-scale experiments and their recovery from chemical stress.
Graphical abstract
Coal production negatively affects the environment by the emission of polycyclic aromatic hydrocarbons (PAHs). Two soils (KOK and KB) from a coking plant area was investigated and their total PAH ...concentration was 40 and 17 mg/kg for the sum (∑) 16 US EPA PAHs, respectively. A third soil was sampled from a bitumen plant area and was characterized by 9 mg/kg ∑16 US EPA PAHs. To reduce the freely dissolved concentration (C
free
) of the PAHs in the soil pore water, active carbon (AC) and two biochars pyrolysed from wheat straw (biochar-S) and willow (biochar-W) were added to the soils at 0.5–5 % (
w/w
), each. The AC performed best and reduced the C
free
by 51–98 % already at the lowest dose. The biochars needed doses up to 2.5 % to significantly reduce the C
free
by 44–86 % in the biochar-S and by 37–68 % in the biochar-W amended soils. The high black carbon (BC) content of up to 2.3 % in the Silesian soils competed with the sorption sites of the carbon amendments and the performance of the remediation was a consequence of the contaminant’s source and the distribution between the BC and the AC/biochars. In contrast, the carbon amendment could best reduce the C
free
in the Lublin soil where the BC content was normal (0.05 %). It is therefore crucial to know the contaminant’s source and history of a sample/site to choose the appropriate carbon amendment not only for remediation success but also for economic reasons.
To protect themselves, plants can produce toxic secondary metabolites (phytotoxins) that appear with widely varying structures and negative effects. These phytotoxins often show similar properties as ...known aquatic micropollutants in terms of mobility, persistence, toxicity, and possibly also ecotoxicity. However, their occurrence in surface waters remains largely unknown, which is also due to unknown ability of available screening approaches to detect them. Therefore, we performed a target and suspect screening based on a persistence-mobility prioritization for phytotoxins in small Swiss creeks using high resolution mass spectrometry. In total, three of 26 targets were detected, three of 78 suspects tentatively identified, and six suspects fully confirmed by reference standards. To the best of our knowledge, it is the first time that three different plant secondary metabolite classes are detected in the same surface water sample. Estrogenic isoflavones were detected at 73% of the sites with formononetin as main toxin, which is in agreement with previous studies. Furthermore, pyrrolizidine alkaloids and the indole alkaloid gramine were detected. Especially pyrrolizidine alkaloids might be critical due to their production by various plants including the invasive
, and their known importance in food and feed safety. Based on these first screening results, different phytotoxin classes should be assessed for their ecotoxicological effects and considered in future water monitoring.
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