Possible Impact of Electric Cars on Electricity Spot Prices

International audienc

Interaction of gold nanoparticles and nickel(II) sulfate affects dendritic cell maturation

Despite many investigations have focused on the pristine toxicity of gold nanoparticles (GNPs), little is known about the outcome of co-exposure and interaction of GNPs with heavy metals which can possibly detoxify or potentiate them. Here, the combined exposure of nickel (II) sulfate (NiSO4) and GNPs on the maturation response of dendritic cells (DCs) was explored. Exposure to GNPs or NiSO4 separately induced cell activation. When cells were exposed to a mixture of both, however, the observed cell activation pattern indicated a competitive rather than an additive effect of both inducers with levels similar to those induced by NiSO4 alone. Quantification of the GNP uptake by DCs demonstrated a significant decrease in intracellular gold content during co-incubation with NiSO4. An extensive physiochemical characterization was performed to determine the interaction between GNPs and NiSO4 in the complex physiological media using nanoparticle tracking analyses, disc centrifugation, UV-visible spectroscopy, ICP-MS analyses, zeta potential measurements, electron microscopy, and proteomics. Although GNPs and NiSO4 did not directly interact with each other, the presence of NiSO4 in the physiological media resulted in changes in GNPs' charge and their associated protein corona (content and composition), which may contribute to a decreased cellular uptake of GNPs and sustaining the nickel-induced DC maturation. The presented results provide new insights in the interaction of heavy metals and NPs in complex physiological media. Moreover, this study highlights the necessity of mixture toxicology, since these combined exposures are highly relevant for human subjection to NPs and risk assessment of nanomaterials.peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=inan20status: publishe

Speciation of inorganic arsenic in particulate matter by combining HPLC/ICP-MS and XANES analyses

Inorganic arsenic species in ambient particulate matter (PM10 and PM2.5) have been determined in an urban area, in the vicinity of a metallurgical industrial plant. The developed high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC/ICP-MS) method allows monitoring of particulate As(iii) and As(v)-species, with a limit of quantification of 0.34 ng m-3 As(iii) and 0.23 ng m-3 As(v), respectively. Good agreement was obtained between the sum of the concentrations of As(iii) and As(v) determined by HPLC/ICP-MS and the total As concentrations determined by XRF, indicating a complete extraction of the As species. During the measuring campaigns for PM10 and PM2.5, a significant conversion (oxidation) up to 54% of exogenous spiked As(iii) was observed. The total amount of the spiked As(iii) was well-recovered (PM10 and PM2.5 on average 108% and 101%, respectively). The extraction of the filter in combination with the sampled air matrix is likely to induce the As(iii) conversion. The average measured As concentration in PM10 during a 40-day monitoring campaign (30 ng m-3) at a hot spot location is above the European target value of 6 ng m-3. The measured As concentration in PM2.5 was half the value of the measured concentration in PM10 and no relative enrichment of total As was observed in either particulate matter fractions. However, in PM10, As(v) was the main component, while in PM2.5, As(iii) was the dominant species. During the monitoring campaign, the fraction of particulate As(iii) varied between 19 and 61% in PM10 and a trend towards a higher fraction of As(iii) with increasing concentration of total As was observed. XANES and XRD analyses were used for the identification of arsenic species in local PM sources and confirmed the presence of Ca3Sr2(AsO4)2.5(PO4)0.5(OH), As2O3 and As2O5 species

Speciation of inorganic arsenic in particulate matter by combining HPLC/ICP-MS and XANES analyses

Inorganic arsenic species in ambient particulate matter (PM10 and PM2.5) have been determined in an urban area, in the vicinity of a metallurgical industrial plant. The developed high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC/ICP-MS) method allows monitoring of particulate As(iii) and As(v)-species, with a limit of quantification of 0.34 ng m-3 As(iii) and 0.23 ng m-3 As(v), respectively. Good agreement was obtained between the sum of the concentrations of As(iii) and As(v) determined by HPLC/ICP-MS and the total As concentrations determined by XRF, indicating a complete extraction of the As species. During the measuring campaigns for PM10 and PM2.5, a significant conversion (oxidation) up to 54% of exogenous spiked As(iii) was observed. The total amount of the spiked As(iii) was well-recovered (PM10 and PM2.5 on average 108% and 101%, respectively). The extraction of the filter in combination with the sampled air matrix is likely to induce the As(iii) conversion. The average measured As concentration in PM10 during a 40-day monitoring campaign (30 ng m-3) at a hot spot location is above the European target value of 6 ng m-3. The measured As concentration in PM2.5 was half the value of the measured concentration in PM10 and no relative enrichment of total As was observed in either particulate matter fractions. However, in PM10, As(v) was the main component, while in PM2.5, As(iii) was the dominant species. During the monitoring campaign, the fraction of particulate As(iii) varied between 19 and 61% in PM10 and a trend towards a higher fraction of As(iii) with increasing concentration of total As was observed. XANES and XRD analyses were used for the identification of arsenic species in local PM sources and confirmed the presence of Ca3Sr2(AsO4)2.5(PO4)0.5(OH), As2O3 and As2O5 species

Interaction of gold nanoparticles and nickel(II) sulfate affects dendritic cell maturation

<p>Despite many investigations have focused on the pristine toxicity of gold nanoparticles (GNPs), little is known about the outcome of co-exposure and interaction of GNPs with heavy metals which can possibly detoxify or potentiate them. Here, the combined exposure of nickel (II) sulfate (NiSO₄) and GNPs on the maturation response of dendritic cells (DCs) was explored. Exposure to GNPs or NiSO₄ separately induced cell activation. When cells were exposed to a mixture of both, however, the observed cell activation pattern indicated a competitive rather than an additive effect of both inducers with levels similar to those induced by NiSO₄ alone. Quantification of the GNP uptake by DCs demonstrated a significant decrease in intracellular gold content during co-incubation with NiSO₄. An extensive physiochemical characterization was performed to determine the interaction between GNPs and NiSO₄ in the complex physiological media using nanoparticle tracking analyses, disc centrifugation, UV–visible spectroscopy, ICP-MS analyses, zeta potential measurements, electron microscopy, and proteomics. Although GNPs and NiSO₄ did not directly interact with each other, the presence of NiSO₄ in the physiological media resulted in changes in GNPs' charge and their associated protein corona (content and composition), which may contribute to a decreased cellular uptake of GNPs and sustaining the nickel-induced DC maturation. The presented results provide new insights in the interaction of heavy metals and NPs in complex physiological media. Moreover, this study highlights the necessity of mixture toxicology, since these combined exposures are highly relevant for human subjection to NPs and risk assessment of nanomaterials.</p

Tackling the salinity-pollution nexus in coastal aquifers from arid regions using nitrate and boron isotopes

Salinization and nitrate pollution are generally ascertained as the main issues affecting coastal aquifers worldwide. In arid zones, where agricultural activities also result in soil salinization, both phenomena tend to co-exist and synergically contribute to alter groundwater quality, with severe negative impacts on human populations and natural ecosystems’ wellbeing. It becomes therefore necessary to understand if and to what extent integrated hydrogeochemical tools can help in distinguishing among possible different salinization and nitrate contamination origins, in order to provide adequate science-based support to local development and environmental protection. The alluvial plain of Bou-Areg (North Morocco) extends over about 190 km2 and is separated from the Mediterranean Sea by the coastal Lagoon of Nador. Its surface is covered for more than 60% by agricultural activities, although the region has been recently concerned by urban population increase and tourism expansion. All these activities mainly rely on groundwater exploitation and at the same time are the main causes of both aquifer and lagoon water quality degradation. For this reason, it was chosen as a case study representative of the typical situation of coastal aquifers in arid zones worldwide, where a clear identification of salinization and pollution sources is fundamental for the implementation of locally oriented remedies and long-term management strategies. Results of a hydrogeochemical investigation performed between 2009 and 2011 show that the Bou-Areg aquifer presents high salinity (often exceeding 100 mg/L in TDS) due to both natural and anthropogenic processes. The area is also impacted by nitrate contamination, with concentrations generally exceeding the WHO statutory limits for drinking water (50 mg/L) and reaching up to about 300 mg/L, in both the rural and urban/peri-urban areas. The isotopic composition of dissolved nitrates (δ15NNO3 and δ18ONO) was used to constrain pollution drivers. The results indicate two main origins for human-induced pollution: (i) manure and septic effluents, especially in urban areas, and (ii) synthetic fertilizers in agricultural areas. In the latter, δ15N-enriched values highlight a mixture of those sources, possibly related to unbalanced fertilization and agricultural return flow. Boron isotopes (δ11B) were hence studied to further distinguish the nitrate origin in the presence of multiple sources and mixing processes. The results indicate that in the study area, the high geochemical background for B and Cl, associated to the complex water-rock interaction processes, limit the application of the coupled δ11B and δ15N isotopic systematics to the detection of sources of groundwater pollution. In fact, despite the exceedingly high nitrate contents, the depleted δ11B values that characterize synthetic fertilizers and sewage leakages could not be detected. Therefore, even if in saline groundwater the anthropogenic contribution has a negligible effect in terms of salinity input, with both sewage and irrigation water not very charged, the associated nitrate content fuels up water-rock interaction processes, eventually leading to a mineralization increase