Formation of metal-cyanide complexes in deliquescent airborne particles: a new possible sink for HCN in urban environments

Hydrogen cyanide is a ubiquitous gas in the atmosphere and a biomass burning tracer. Reactive gasses can be adsorbed onto aerosol particles where they can promote heterogeneous chemistry. In the present study, we report for the first time on the measurement and speciation of cyanides in atmospheric aerosol. Filter samples were collected at an urban background site in the city center of Padua (Italy), extracted and analyzed with headspace gas chromatography and nitrogen-phosphorous detection. The results showed that strongly bound cyanides were present in all aerosol samples at a concentration ranging between 0.3 and 6.5 ng/m3 in the PM2.5 fraction. The concentration of cyanides strongly correlates with concentration of total carbon and metals associated with combustion sources. The results obtained bring evidence that hydrogen cyanide can be adsorbed onto aerosol liquid water and can react with metal ions to form stable metal-cyanide complexes

A new method to assess the acute toxicity toward honeybees of the abrasion particles generated from seeds coated with insecticides

Background:Large amounts of insecticide-containing dusts produced from abrasion of the seed dressing can be released into the atmosphere during sowing operations. Neonicotinoid pesticides, introduced in the 1990s for several crops, are the leading products for seed-coating treatments in many countries. Neonicotinoid containing dusts can be effectively intercepted by bees in flight over the sowing field, inducing lethal acute effects, so that restrictions in the use of the main neonicotinoids have been adopted in the European Union. This led to the consequent introduc-tion of replacement insecticides for seed-coating, i.e. methiocarb and thiacloprid, despite the lack of information on both the toxicity and the exposure scenarios for honeybees. Results:In this study, a laboratory apparatus was developed in order to quantify the toxicity of the dusts produced from the abrasion of the seed coating. This quantification is based on (i) an airstream transporting coating particles into an exposure chamber; (ii) exposure of bees to reproducible and measurable concentrations of insecticide, and (iii) direct measurement of the exposure dose on single bees. The method allowed us to perform in vivo experiments of honeybee exposure to provide toxicity data in more realistic exposure conditions. In fact, the formulation rather than the active principle alone can be tested, and the exposure is through dusts rather than a solution so that specific absorption behavior can be studied in representative environmental conditions. The method was used to quantify the acute toxicity (LD50) of dusts obtained from the abrasion of corn seeds coated with clothianidin, thiacloprid and methiocarb. Conclusions:Our results show that, surprisingly, the replacement insecticide methiocarb has a toxicity (LD50= 421\u2013693 ng/bee) in the same order of magnitude as clothianidin (LD50=113\u2013451 ng/bee) through this specific exposure route, while thiacloprid (LD50= 16.9\ub7103 ng/bee) has a significantly lower acute toxicity. Moreover, dusts containing methiocarb and clothianidin show a significant increase in toxicity when, after exposure, bees are kept under high humidity conditions. This suggests that the method here presented can be used to obtain complementary toxicity data in the risk assessment procedure for the authorization of new seed-coating insecticides or new formulations

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 1: new molecules, metabolism, fate, and transport

With the exponential number of published data on neonicotinoids and fipronil during the last decade, an updated review of literature has been conducted in three parts. The present part focuses on gaps of knowledge that have been addressed after publication of the Worldwide Integrated Assessment (WIA) on systemic insecticides in 2015. More specifically, new data on the mode of action and metabolism of neonicotinoids and fipronil, and their toxicity to invertebrates and vertebrates, were obtained. We included the newly detected synergistic effects and/or interactions of these systemic insecticides with other insecticides, fungicides, herbicides, adjuvants, honeybee viruses, and parasites of honeybees. New studies have also investigated the contamination of all environmental compartments (air and dust, soil, water, sediments, and plants) as well as bees and apicultural products, food and beverages, and the exposure of invertebrates and vertebrates to such contaminants. Finally, we review new publications on remediation of neonicotinoids and fipronil, especially in water systems. Conclusions of the previous WIA in 2015 are reinforced; neonicotinoids and fipronil represent a major threat worldwide for biodiversity, ecosystems, and all the services the latter provide

Methiocarb metabolites are systemically distributed throughout corn plants grown from coated seeds

Funder: Università degli Studi di PadovaAbstract: Systemic insecticides such as neonicotinoids are widely used in seed coating practices for pest control in many crops, e.g., corn. Their success is due to their ability to protect the whole plant, from the roots to the upper leaves, but their use at high amounts is causing possible adverse effects on non-target animals exposed to contaminated pollen, nectar, leaves, and dust emitted during sowing. In 2018, the European Union banned some neonicotinoids and fipronil as seed coating insecticides in open fields. Consequently, the methylcarbamate methiocarb and less-toxic neonicotinoids, e.g., thiacloprid, have been authorized and largely used as alternative pesticides for corn seed coating. Here, an analytical protocol based on QuEChERS extraction/purification procedure and analysis by liquid chromatography-mass spectrometry has been optimized for the identification and the quantification of methiocarb, thiamethoxam, thiacloprid, and their metabolites in guttation drops, the xylem fluid excreted at leaf margins, and in leaves of corn plants grown from coated seeds. Although methiocarb is a non-systemic pesticide, we unexpectedly found high concentrations of its metabolites in both guttations and leaves, whereas methiocarb itself was below detection limits in most of the samples. The methiocarb main metabolite, methiocarb sulfoxide, was found at a mean concentration of 0.61 ± 1.12 µg mL−1 in guttation drops and 4.4 ± 2.1 µg g−1 in leaves. Conversely, parent compounds of neonicotinoids (thiamethoxam, thiacloprid) are systemically distributed in corn seedlings. This result raises safety concerns given that methiocarb sulfoxide is more toxic than the parent compound for some non-target species

The effects of glomerular and tubular renal progenitors and derived extracellular vesicles on recovery from acute kidney injury

BACKGROUND: Mesenchymal stromal cells (MSCs) and renal stem/progenitors improve the recovery of acute kidney injury (AKI) mainly through the release of paracrine mediators including the extracellular vesicles (EVs). Several studies have reported the existence of a resident population of MSCs within the glomeruli (Gl-MSCs). However, their contribution towards kidney repair still remains to be elucidated. The aim of the present study was to evaluate whether Gl-MSCs and Gl-MSC-EVs promote the recovery of AKI induced by ischemia-reperfusion injury (IRI) in SCID mice. Moreover, the effects of Gl-MSCs and Gl-MSC-EVs were compared with those of CD133(+) progenitor cells isolated from human tubules of the renal cortical tissue (T-CD133(+) cells) and their EVs (T-CD133(+)-EVs). METHODS: IRI was performed in mice by clamping the left renal pedicle for 35 minutes together with a right nephrectomy. Immediately after reperfusion, the animals were divided in different groups to be treated with: Gl-MSCs, T-CD133(+) cells, Gl-MSC-EVs, T-CD133(+)-EVs or vehicle. To assess the role of vesicular RNA, EVs were either isolated by floating to avoid contamination of non-vesicles-associated RNA or treated with a high dose of RNase. Mice were sacrificed 48 hours after surgery. RESULTS: Gl-MSCs, and Gl-MSC-EVs both ameliorate kidney function and reduce the ischemic damage post IRI by activating tubular epithelial cell proliferation. Furthermore, T-CD133(+) cells, but not their EVs, also significantly contributed to the renal recovery after IRI compared to the controls. Floating EVs were effective while RNase-inactivated EVs were ineffective. Analysis of the EV miRnome revealed that Gl-MSC-EVs selectively expressed a group of miRNAs, compared to EVs derived from fibroblasts, which were biologically ineffective in IRI. CONCLUSIONS: In this study, we demonstrate that Gl-MSCs may contribute in the recovery of mice with AKI induced by IRI primarily through the release of EVs. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13287-017-0478-5) contains supplementary material, which is available to authorized users

Formation of metal-organic ligand complexes affects solubility of metals in airborne particles at an urban site in the Po valley

Abstract Metals in atmospheric aerosols play potentially an important role in human health and ocean primary productivity. However, the lack of knowledge about solubility and speciation of metal ions in the particles or after solubilisation in aqueous media (sea or surface waters, cloud or rain droplets, biological fluids) limits our understanding of the underlying physico-chemical processes. In this work, a wide range of metals, their soluble fractions, and inorganic/organic compounds contained in urban particulate matter (PM) from Padua (Italy) were determined. Metal solubility tests have been performed by dissolving the PM in water and in solutions simulating rain droplet composition. The water-soluble fractions of the metal ions and of the organic compounds having ligand properties have been subjected to a multivariate statistical procedure, in order to elucidate associations among the aqueous concentrations of these PM components in simulated rain droplets. In parallel, a multi-dimensional speciation calculation has been performed to identify the stoichiometry and the amount of metal-ligand complexes theoretically expected in aqueous solutions. Both approaches showed that the solubility and the aqueous speciation of metal ions were differently affected by the presence of inorganic and organic ligands in the PM. The solubility of Al, Cr, and Fe was strongly correlated to the concentrations of oxalic acid, as their oxalate complexes represented the expected dominant species in aqueous solutions. Oxalates of Al represented ∼98% of soluble Al, while oxalates of Cu represented 34–75% of the soluble Cu, and oxalates of Fe represented 76% of soluble Fe. The oxidation state of Fe can strongly impact the speciation picture. If Fe is present as Fe(II) rather than Fe(III), the amount of Cr and Cu complexed with diacids can increase from 75% to 94%, and from 32% to 53%, respectively. For other metals, the solubility depended on the formation of soluble aquo-complexes, hence with a scarce effect of the organic ligands. An iron-oxalate complex was also directly detected in aerosol sample extracts

metal ion release from fine particulate matter sampled in the po valley to an aqueous solution mimicking fog water kinetics and solubility

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Sustainability of using vineyard pruning residues as an energy source: Combustion performances and environmental impact

Open burning of agricultural waste is still a common practice as it is a rapid method for waste disposal, although natural biomass, including agriculture residues, can be exploited as a renewable energy source. We assessed the viability and sustainability of using vineyard pruning residues, as wood chips, for energy conversion. Wood chips, obtained from vineyards in the Prosecco DOCG region (Italy), were characterized in terms of chemical composition, calorific value, ash content and humidity. Combustion tests were performed in a medium-size biomass boiler (maximum power 500 kW) to assess the viability of the approach in terms of sustainable steady-state combustion. Primary emissions of both macro- and micro-pollutants were measured to assess the environmental impact. An analytical method was purposely developed for the determination of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and in three matrices: fly ashes, condensate and gas. The results showed that vineyard pruning residues can be used for energy conversion in medium- and large-scale biomass boilers. Primary emissions of measured pollutants were all below limit values set by current European legislation except for particulate matter, for which current available abatement technologies are required to contain emissions, abatement technologies are required to contain emissions, thus making the use of vineyard pruning residues unsuitable for combustion in domestic appliances where such technologies are not installed. Bottom ashes produced during combustion were also characterized to assess whether they can be recycled in the vineyard as soil amendments/fertilizer. Copper content in combustion ashes exceeded limit values for ashes to be used as fertilizers in agricultural fields for some European countries but not for others, indicating that ashes may need to be disposed as waste

Biomarkers of Acute Graft-Versus-Host Disease: Surface Antigens and Micro Rnas in Extracellular Vesicles

Introduction Biomarkers could be crucial to identify patients at high-risk of acute Graft-vs.-Host Disease (aGVHD). Given their involvement in inflammation, Extracellular Vesicles (EVs) may become attractive biomarkers. Moreover, EVs are non-invasively extracted from body fluids. In a preliminary study, we significantly correlated CD146, CD31 and CD140a expression on EVs membranes with the onset of aGVHD (Lia G. Leukemia 2017). Objectives We designed a prospective study to further characterize EVs by their surface antigens and by their content in MicroRNAs. Methods EVs are extracted from serum samples at given time-points (pre-transplant, on day 0, 3, 7, 14, 21, 28, 35, 45 and then monthly up to 1 year) by a protamine-based precipitation method and analyzed by flow-cytometry (Guava EasyCyte Flow Cytometer) for the expression of 13 membrane proteins (CD44, CD138, CD146, KRT18, CD120a, CD8, CD30, CD106, CD25, CD31, CD144, CD86, and CD140a). MicroRNAs (miR100, miR92b, miR155, miR194) are extracted from EVs at pre- transplant and on day 0, 7, 14, 28, and quantified by real time PCR as relative quantification compared to healthy donors after cDNA Reverse Transcription. Logistic Regression Analysis is performed for each marker. Results Thirty-five transplant patients with hematological diseases have so far been enrolled. Seventeen/35 patients (49%) developed grade II-IV aGVHD. Our preliminary findings show that CD146 (melanoma cell adhesion molecule, MCAM-1) and CD44 (homing-associated cell adhesion molecule, H-CAM) were associated with an increased risk of aGVHD (Odds Ratio (OR) 4.3, p=0.008; OR 2.1, p=0.039), whereas CD31 (platelet endothelial cell adhesion molecule, PECAM-1) level was associated with a decreased risk of aGVHD (OR 0.31, p=0.001). Moreover, increased risk of aGVHD was significantly correlated with levels of miR100 (OR 4.66, p=0.004), miR194 (OR 2.2, p=0.01) and miR155 (OR 3.56, p=0.035). Of note, biomarkers associated with aGVHD showed a constant consensual change in signal levels before aGVHD onset (Figure 1). Conclusions An association of 3 EVs membrane antigens and onset of aGVHD was observed. Of note, CD146, CD44 and CD31 belong to the Cell Adhesion Molecule Family and are critical for endothelium and immune cells interactions. The functional role of miR-194 in GVHD pathogenesis remains to be determined while JAK/STAT and TGFβ pathways were shown to be involved in other studies (Gimondi S Exp Hematol, 2016). MiR-100 has been reported to regulate inflammatory neovascularization during GvHD (Leonhardt F, Blood 2013) while miR-155 drives donor T cell expansion and tissue infiltration (Zitzer N, J Immunol 2018, Ranganathan P Blood 2012)

Environmental fate and exposure; neonicotinoids and fipronil

Systemic insecticides are applied to plants using a wide variety of methods, ranging from foliar sprays to seed treatments and soil drenches. Neonicotinoids and fipronil are among the most widely used pesticides in the world. Their popularity is largely due to their high toxicity to invertebrates, the ease and flexibility with which they can be applied, their long persistence, and their systemic nature, which ensures that they spread to all parts of the target crop. However, these properties also increase the probability of environmental contamination and exposure of nontarget organisms. Environmental contamination occurs via a number of routes including dust generated during drilling of dressed seeds, contamination and accumulation in arable soils and soil water, runoff into waterways, and uptake of pesticides by nontarget plants via their roots or dust deposition on leaves. Persistence in soils, waterways, and nontarget plants is variable but can be prolonged; for example, the half-lives of neonicotinoids in soils can exceed 1,000 days, so they can accumulate when used repeatedly. Similarly, they can persist inwoody plants for periods exceeding 1 year. Breakdown results in toxic metabolites, though concentrations of these in the environment are rarely measured. Overall, there is strong evidence that soils, waterways, and plants in agricultural environments and neighboring areas are contaminated with variable levels of neonicotinoids or fipronil mixtures and their metabolites (soil, parts per billion (ppb)-parts per million (ppm) range; water, parts per trillion (ppt)-ppb range; and plants, ppb-ppm range). This provides multiple routes for chronic (and acute in some cases) exposure of nontarget animals. For example, pollinators are exposed through direct contact with dust during drilling; consumption of pollen, nectar, or guttation drops from seed-treated crops, water, and consumption of contaminated pollen and nectar from wild flowers and trees growing near-treated crops. Studies of food stores in honeybee colonies from across the globe demonstrate that colonies are routinely and chronically exposed to neonicotinoids, fipronil, and their metabolites (generally in the 1-100 ppb range), mixed with other pesticides some of which are known to act synergistically with neonicotinoids. Other nontarget organisms, particularly those inhabiting soils, aquatic habitats, or herbivorous insects feeding on noncrop plants in farmland, will also inevitably receive exposure, although data are generally lacking for these groups. We summarize the current state of knowledge regarding the environmental fate of these compounds by outlining what is known about the chemical properties of these compounds, and placing these properties in the context of modern agricultural practices