Insights into the Porretta Terme (northern Apennines,Italy) hydrothermal system revealed by geochemical data on presently discharging thermal waters and paleofluids

Environmental Geochemistry and Health - This study focuses on the geochemical features of the presently discharging thermal and cold springs and on paleofluids from the upstream portion of the Reno...     

Mechanisms contributing to the thermal analysis of waste incineration bottom ash and quantification of different carbon species

The focus of this study was to identify the main compounds affecting the weight changes of bottom ash (BA) in conventional loss on ignition (LOI) tests and to obtain a better understanding of the individual processes in heterogeneous (waste) materials such as BA. Evaluations were performed on BA samples from a refuse derived fuel incineration (RDF-I) plant and a hospital waste incineration (HW-I) plant using thermogravimetric analysis and subsequent mass spectrometry (TG–MS) analysis of the gaseous thermal decomposition products. Results of TG–MS analysis on RDF-I BA indicated that the LOI measured at 550 °C was due to moisture evaporation and dehydration of Ca(OH)₂ and hydrocalumite. Results for the HW-I BA showed that LOI at 550 °C was predominantly related to the elemental carbon (EC) content of the sample. Decomposition of CaCO₃ around 700 °C was identified in both materials. In addition, we have identified reaction mechanisms that underestimate the EC and overestimate the CaCO₃ contents of the HW-I BA during TG–MS analyses. These types of artefacts are expected to occur also when conventional LOI methods are adopted, in particular for materials that contain CaO/Ca(OH)₂ in combination with EC and/or organic carbon, such as e.g. municipal solid waste incineration (MSWI) bottom and fly ashes. We suggest that the same mechanisms that we have found (i.e. in situ carbonation) can also occur during combustion of the waste in the incinerator (between 450 and 650 °C) demonstrating that the presence of carbonate in bottom ash is not necessarily indicative for weathering. These results may also give direction to further optimization of waste incineration technologies with regard to stimulating in situ carbonation during incineration and subsequent potential improvement of the leaching behavior of bottom ash.     

Prenatal diagnosis of a mosaic supernumerary marker iso (8p) (tetrasomy 8p): discordance between chorionic villi culture and amniotic fluid karyotypes

We describe the first case of mosaic supernumerary marker iso (8p) displaying a karyotype discordance between chorionic villi (CV) and amniotic fluid (AF) cultures during prenatal cytogenetic diagnosis. In the first trimester, cytogenetic analysis after chorionic villi sampling (CVS) was normal in all metaphases in the short-term cytotrophoblast cell culture, but an undefined supernumerary marker was detected in 60% of mesenchymal cells in the long-term CV culture. Informed of the mosaicism, the couple selected amniotic fluid sampling as a second-trimester confirmatory diagnostic procedure. The supernumerary marker was absent in all of the 25 available AF cells metaphases. The prospective parents received genetic counselling and were informed that the discordance could be interpreted as a placental confined mosaicism or as a true foetal mosaicism with low percentage of affected cells. The couple opted to continue the pregnancy. In the second month of life, the child had abnormal development with severe psychomotor delay and frequent episodes of epilepsy. Postnatal cytogenetic extensive re-evaluation discovered that the previously detected supernumerary marker was indeed an isochromosome (8p) rearrangement present at low frequency in 5% of the blood lymphocytes. Copyright © 2006 John Wiley & Sons, Ltd.     

Contamination of different portions of raw and boiled specimens of Norway lobster by mercury and selenium

The aim of this study was to evaluate mercury and selenium distribution in different portions (exoskeleton, white meat and brown meat) of Norway lobster (Nephrops norvegicus). Some samples were also analysed as whole specimens. The same portions were also examined after boiling, in order to observe if this cooking practice could affect mercury and selenium concentrations. The highest mercury concentrations were detected in white meat, exceeding in all cases the maximum levels established by European legislation. The brown meat reported the highest selenium concentrations. In all boiled samples, mercury levels showed a statistically significant increase compared to raw portions. On the contrary, selenium concentrations detected in boiled samples of white meat, brown meat and whole specimen showed a statistically significant decrease compared to the corresponding raw samples. These results indicate that boiling modifies mercury and selenium concentrations. The high mercury levels detected represent a possible risk for consumers, and the publication and diffusion of specific advisories concerning seafood consumption is recommended.     

The non-participation of organic sulphur in acid mine drainage generation

Acid mine drainage is commonly associated with land disturbances that encounter and expose iron sulphides to oxidising atmospheric conditions. The attendant acidic conditions solubilise a host of trace metals. Within this flow regime the potential exists to contaminate surface drinking water supplies with a variety of trace materials. Accordingly, in evaluating the applications for mines located in the headwaters of water sheds, the pre-mining prediction of the occurrence of acid mine drainage is of paramount importance.There is general agreement among investigators that coal organic sulphur is a nonparticipant in acid mine drainage generation; however, there is no scientific documentation to support this concensus. Using simulated weathering, kinetic, mass balance, petrographic analysis and a peroxide oxidation procedure, coal organic sulphur is shown to be a nonparticipant in acid mine drainage generation. Calculations for assessing the acid-generating potential of a sedimentary rock should not include organic sulphur content.     

Genotoxicity of gold nanoparticles functionalized with indolicidin towards Saccharomyces cerevisiae

The toxic effects of gold nanoparticles surface-functionalized with the antimicrobial peptide indolicidin(Au NPs-indolicidin) towards the yeast Saccharomyces cerevisiae, one of the major eukaryotic model organisms, have been evaluated. Growth and survival,genotoxicity, as measured by comet assay, and expression of the YCA1, an apoptosis indicating gene, following 72 hr exposure of yeast to Au NPs-indolicidin, and to Au NPs and indolicidin alone have been examined. The gold nanoparticles exerted toxicity with DNA damage, accompanied by reactive oxygen species production(ROS), but they do not inhibit yeast growth and viability. Genotoxicity was less pronounced for surface-functionalized nanoparticles, showing that S. cerevisiae is quite resistant to the complex Au NPs-indolicidin.A progressive reduction of the genotoxic effect was observed along 72 hr exposure,presumably due to the activation of DNA repair mechanisms. These findings suggest the occurrence of a physiological protective response of S. cerevisiae towards nanoparticles,thereby providing useful information to the assessment of the environmental impact of metal nanoparticles.