Characterization of trace elements in thermal and mineral waters of Greece.

Natural thermal and mineral waters are widely distributed along the Hellenic region and are related to the geodynamic regime of the country. The diverse lithological and tectonic settings they are found in reflect the great variability in their chemical and isotopic composition. The current study presents 276 (published and unpublished) trace element water data and discusses the sources and processes affecting the water by taking into consideration the framework of their geographic distribution. The dataset is divided in groups using temperature- and pH-related criteria. Results yield a wide range of concentrations, often related to the solubility properties of the individual elements and the factors impacting them (i.e. temperature, acidity, redox conditions and salinity). Many elements (e.g. alkalis, Ti, Sr, As and Tl) present a good correlation with temperature, which is in cases impacted by water rock interactions, while others (e.g. Be, Al, Cu, Se, Cd) exhibit either no relation or an inverse correlation with T possibly because they become oversaturated at higher temperatures in solid phases. A moderately constant inverse correlation is noticed for the vast majority of trace elements and pH, whereas no relationship between trace element concentrations and Eh was found. Seawater contamination and water-rock interaction seem to be the main natural processes that influence both salinity and elemental content. All in all, Greek thermomineral waters exceed occasionally the accepted limits representing in such cases serious harm to the environment and probably indirectly (through the water cycle) to human health.

Atmospheric Deposition around the Industrial Areas of Milazzo and Priolo Gargallo (Sicily-Italy)-Part A: Major Ions.

The chemical composition of rainwater was studied in two highly-industrialised areas in Sicily (southern Italy), between June 2018 and July 2019. The study areas were characterised by large oil refining plants and other industrial hubs whose processes contribute to the release of large amounts of gaseous species that can affect the chemical composition of atmospheric deposition As in most of the Mediterranean area, rainwater acidity (ranging in the study area between 3.9 and 8.3) was buffered by the dissolution of abundant geogenic carbonate aerosol. In particular, calcium and magnesium cations showed the highest pH-neutralizing factor, with ~92% of the acidity brought by SO42- and NO3- neutralized by alkaline dust. The lowest pH values were observed in samples collected after abundant rain periods, characterised by a less significant dry deposition of alkaline materials. Electrical Conductivity (ranging between 7 µS cm-1 and 396 µS cm-1) was inversely correlated with the amount of rainfall measured in the two areas. Concentrations of major ionic species followed the sequence Cl- > Na+ > SO42- ≃ HCO3- > ≃ Ca2+ > NO3- > Mg2+ > K+ > F-. High loads of Na+ and Cl- (with a calculated R2 = 0.99) reflected proximity to the sea. Calcium, potassium, and non-sea-salt magnesium had a prevalent crustal origin. Non-sea salt sulphate, nitrate, and fluoride can be attributed mainly to anthropogenic sources. Mt. Etna, during eruptive periods, may be also considered, on a regional scale, a significant source for fluoride, non-sea salt sulphate, and even chloride.

Geochemical characterisation of the thermo-mineral waters of Greece.

Geothermal areas of Greece are located in regions affected by recent volcanism and in continental basins characterised by elevated heat flow. Many of them are found along the coast, and thus, water is often saline due to marine intrusion. In the current study, we present about 300 unpublished and literature data from thermal and cold mineral waters collected along Greece. Samples were analysed for major ions, Li, SiO2 and isotopes in water. Measured temperatures range from 6.5 to 98 °C, pH from 1.96 to 11.98, while Total Dissolved Solutes (TDS) from 0.22 to 51 g/L. Waters were subdivided into four main groups: (1) thermal; (2) cold; (3) acidic (pH < 5); and (4) hyperalkaline (pH > 11). On statistical basis, thermal waters were subdivided into subgroups according to both their temperature [warm (< 29 °C), hypothermal (29-48 °C), thermal (48-75 °C) and hyperthermal (> 75 °C)] and TDS [low salinity (< 4 g/L), brackish (4-30 g/L) and saline (> 30 g/L)]. Cold waters were subdivided based on their pCO2 [low (< 0.05 atm), medium (0.05-0.85 atm) and high (> 0.85 atm)]. δ18O-H2O ranges from - 12.7 to + 2.7‰ versus SMOW, while δ2H-H2O from - 91 to + 12‰ versus SMOW being generally comprised between the Global Meteoric Water Line and the East Mediterranean Meteoric Water Line. Positive δ18O shifts with respect to the former are mostly related to mixing with seawater, while only for a few samples these shifts point to high-temperature water-rock interaction processes. Only a few thermal waters gave reliable geothermometric estimates, suggesting reservoir temperatures between 80 and 260 °C.

Geochemical characterization and health risk assessment in two diversified environmental settings (Southern Italy).

An integrated approach using chemical and microbial indicators has been tested in two different sites of the Campania Plain (Southern Italy) with different land use covering and different hydrogeological features in order: (1) to define the water-rock interaction processes, (2) to differentiate sources of pollution in a detailed way (3) to evaluate the degree of water quality in the studied alluvial aquifer and (4) to identify the most worrying elements for human's health. Groundwater have showed a HCO3-Ca signature for both investigated sites, and a progressive enrichment in alkali ions has been highlighted moving from the boundary of the plain toward the coastal areas, due to groundwater interaction with volcanic rocks along the flow path. The application of the Factor Analysis allowed to identify different sources of pollution, which were attributed to (a) leaks in the sewer system for the Agro-Aversano Area and also the spreading of manure as fertilizers in agricultural activities for the Caiazzo Plain. Furthermore, it has been highlighted that the use of major elements, trace elements and microbiological indicators, allows to accurately differentiate contamination processes in progress. In fact, from the results of the Factor Analysis applied in the Agro-Aversano area, no significant statistically relationships between major elements and microbiological indicators of fecal contamination were highlighted, unlike the Caiazzo plain where statistically significant correlations have been found between major and trace elements and microbiological indicators. The use of a Groundwater Quality Index has shown general poor water quality for the majority of analyzed samples due to the high amount of Nitrate and Fecal indicators. The use of a Health Risk Assessment highlighted that Nitrate coupled with Fluoride represent the most important concern for human health compared to the all investigated parameters in both sites.

Geosphere-biosphere interactions in bio-activity volcanic lakes: evidences from Hule and Rìo Cuarto (Costa Rica).

Hule and Río Cuarto are maar lakes located 11 and 18 km N of Poás volcano along a 27 km long fracture zone, in the Central Volcanic Range of Costa Rica. Both lakes are characterized by a stable thermic and chemical stratification and recently they were affected by fish killing events likely related to the uprising of deep anoxic waters to the surface caused by rollover phenomena. The vertical profiles of temperature, pH, redox potential, chemical and isotopic compositions of water and dissolved gases, as well as prokaryotic diversity estimated by DNA fingerprinting and massive 16S rRNA pyrosequencing along the water column of the two lakes, have highlighted that different bio-geochemical processes occur in these meromictic lakes. Although the two lakes host different bacterial and archaeal phylogenetic groups, water and gas chemistry in both lakes is controlled by the same prokaryotic functions, especially regarding the CO2-CH4 cycle. Addition of hydrothermal CO2 through the bottom of the lakes plays a fundamental priming role in developing a stable water stratification and fuelling anoxic bacterial and archaeal populations. Methanogens and methane oxidizers as well as autotrophic and heterotrophic aerobic bacteria responsible of organic carbon recycling resulted to be stratified with depth and strictly related to the chemical-physical conditions and availability of free oxygen, affecting both the CO2 and CH4 chemical concentrations and their isotopic compositions along the water column. Hule and Río Cuarto lakes were demonstrated to contain a CO2 (CH4, N2)-rich gas reservoir mainly controlled by the interactions occurring between geosphere and biosphere. Thus, we introduced the term of bio-activity volcanic lakes to distinguish these lakes, which have analogues worldwide (e.g. Kivu: D.R.C.-Rwanda; Albano, Monticchio and Averno: Italy; Pavin: France) from volcanic lakes only characterized by geogenic CO2 reservoir such as Nyos and Monoun (Cameroon).

Colloidal stability of nanoparticles derived from simulated cloud-processed mineral dusts.

Laboratory simulation of cloud processing of three model dust types with distinct Fe-content (Moroccan dust, Libyan dust and Etna ash) and reference goethite and ferrihydrite were conducted in order to gain a better understanding of natural nanomaterial inputs and their environmental fate and bioavailability. The resulting nanoparticles (NPs) were characterised for Fe dissolution kinetics, aggregation/size distribution, micromorphology and colloidal stability of particle suspensions using a multi-method approach. We demonstrated that the: (i) acid-leachable Fe concentration was highest in volcanic ash (1 m Mg(-1) dust) and was followed by Libyan and Moroccan dust with an order of magnitude lower levels; (ii) acid leached Fe concentration in the<20 nm fraction was similar in samples processed in the dark with those under artificial sunlight, but average hydrodynamic diameter of NPs after cloud-processing (pH~6) was larger in the former; iii) NPs formed at pH~6 were smaller and less poly-disperse than those at low pH, whilst unaltered zeta potentials indicated colloidal instability; iv) relative Fe percentage in the finer particles derived from cloud processing does not reflect Fe content of unprocessed dusts (e.g. volcanic ash>Libyan dust). The common occurrence of Fe-rich "natural nanoparticles" in atmospheric dust derived materials may indicate their more ubiquitous presence in the marine environment than previously thought.

Circulating levels of adhesion molecules in chronic kidney disease correlate with the stage of renal disease and with C-reactive protein.

BACKGROUND: Patients with chronic renal failure (CRF) suffer from a series of complications linked to the atherosclerotic process in which the endothelial dysfunction mediated by the activation of some adhesion molecules plays an important role. This study aims to evaluate circulating levels of intercellular adhesion molecules-1 (ICAM-1) and vascular cell adhesion molecules-1 (VCAM-1) in patients with predialysis CRF, on maintenance hemodialysis (HD) and after kidney transplantation (KTx) and to correlate them with some inflammation and nutritional indexes. METHODS: Thirty two patients with predialysis CRF, 30 on maintenance HD, 36 after KTx and 28 subjects as a control group (C) were included in this study. Circulating levels of ICAM-1 and VCAM-1 were assayed using a specific sandwich ELISA kit. As inflammation indexes, TNFalpha and C-reactive protein (CRP) and, as nutritional indexes, body mass index (BMI), serum albumin, cholesterol, triglycerides, and fibrinogen (F) were evaluated. RESULTS: Serum levels of ICAM-1 and VCAM-1 were progressively higher from C to KTx patients, to those with CRF and those on HD (ANOVA for both; p <0.001). TNFalpha values were lower in HD subjects than in CRF patients, even if in both groups TNFalpha levels were greater than in Tx and control subjects. F and CRP were higher in CRF and HD vs. Tx and control subjects (ANOVA for both p <0.001). No significant correlations were observed between soluble adhesion molecules, albumin and cholesterol, whereas significant correlations were found between CRP and ICAM-1 (r = 0.41; p <0.01), CRP and VCAM-1 (r = 0.39; p <0.01) and between CRP and TNFalpha (r = 0.42; p <0.01). These correlations remained statistically significant even after adjustment for age and blood pressure (all p <0.01). BMI did not differ in the three patient groups. CONCLUSIONS: Circulating levels of adhesion molecules in our study correlated positively with the stage of disease and with one of the inflammatory indexes (CRP), but not with nutritional indexes such as BMI, cholesterol and albumin. The clinical significance of our findings warrants further investigation.

Conversion to a proliferation signal inhibitor in a patient with coronary artery disease--a case report.

The calcineurin inhibitors (CNIs) ciclosporin (CsA) and tacrolimus are currently an important part of immunosuppressive regimens, but are associated with increased cardiovascular risk factors, including hyperlipidaemia, hypertension and diabetes mellitus. Conversion from CNI-based regimens to proliferation signal inhibitors or mammalian target of rapamycin inhibitors, such as everolimus and sirolimus, has been associated with an improvement in cardiovascular risk. This case study describes a 59-year-old renal transplant recipient who presented with angina pectoris while receiving immunosuppression with CsA, azathioprine and steroids. The patient developed angina pectoris 5 years after receiving a cadaveric renal transplant. At the time, the patient was obese, with hypertension controlled with diuretics and calcium channel blockers, and hyperlipidaemia controlled with statins. A scintigram revealed plurisegmental myocardial ischaemia, and a coronary angiogram showed the presence of occlusions in the left anterior descending artery and circumflex coronary artery. The patient also had 70% stenosis of the right coronary artery, which was corrected by angioplastic percutaneous intervention. The patient was converted from azathioprine to sirolimus 2 mg/day (trough blood level, 6-10 ng/ml), while the CsA dose was tapered and withdrawn. The angina pectoris subsequently resolved, no progression of coronary artery disease (CAD) has been observed during follow-up and stable renal function has been maintained throughout. Conversion to an immunosuppressive regimen of sirolimus with CsA withdrawal, along with angioplastic percutaneous correction of right coronary artery stenosis, therefore led to the complete resolution of angina pectoris and no progression of the CAD was noticed in this obese renal transplant patient with drug-controlled hypertension and hyperlipidaemia.