Tracing groundwater salinization processes in coastal aquifers: a hydrogeochemical and isotopic approach in Na-Cl brackish waters of north-western Sardinia, Italy

Abstract. Throughout the Mediterranean, salinization threatens water quality, especially in coastal areas. This salinization is the result of concomitant processes related to both seawater intrusion and water–rock interaction, which in some cases are virtually indistinguishable. In the Nurra region of northwestern Sardinia, recent salinization related to marine water intrusion has been caused by aquifer exploitation. However, the geology of this region records a long history from the Palaeozoic to the Quaternary, and is structurally complex and comprises a wide variety of lithologies, including Triassic evaporites. Determining the origin of the saline component of the Jurassic and Triassic aquifers in the Nurra region may provide a useful and more general model for salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activity and recent climatic change, the Nurra has become vulnerable to desertification and, in common with other Mediterranean islands, surface water resources periodically suffer from severe shortages. With this in mind, we report new data regarding brackish and surface waters (outcrop and lake samples) of the Na-Cl type from the Nurra region, including major ions and selected trace elements (B, Br, I, and Sr), in addition to isotopic data including δ18O, δD in water, and δ34S and δ18O in dissolved SO4. To identify the origin of the salinity more precisely, we also analysed the mineralogical and isotopic composition of Triassic evaporites. The brackish waters have Cl contents of up to 2025 mg L−1 , and the ratios between dissolved ions and Cl, with the exception of the Br / Cl ratio, are not those expected on the basis of simple mixing between rainwater and seawater. The δ18O and δD data indicate that most of the waters fall between the regional meteoric water line and the global meteoric water line, supporting the conclusion that they are meteoric in origin. A significant consequence of the meteoric origin of the Na-Cl-type water studied here is that the Br / Cl ratio, extensively used to assess the origin of salinity in fresh water, should be used with care in carbonate aquifers that are near the coast. Overall, δ34S and δ18O levels in dissolved SO4 suggest that water–rock interaction is responsible for the Na-Cl brackish composition of the water hosted by the Jurassic and Triassic aquifers of the Nurra, and this is consistent with the geology and lithological features of the study area. Evaporite dissolution may also explain the high Cl content, as halite was detected within the gypsum deposits. Finally, these Na-Cl brackish waters are undersaturated with respect to the more soluble salts, implying that in a climate evolving toward semi-arid conditions, the salinization process could intensify dramatically in the near future

Sex differences in proximal femur shape : findings from a population-based study in adolescents

We are extremely grateful to all the families who took part in this study, the midwives for their help in recruiting them, and the whole ALSPAC team, which includes interviewers, computer and laboratory technicians, clerical workers, research scientists, volunteers, managers, receptionists, and nurses. The UK Medical Research Council and the Wellcome Trust (ref: 102215/2/13/2) and the University of Bristol provide core support for ALSPAC. MF was supported by a Wellcome Trust PhD studentship (ref: 105504/Z/14/Z). LP works in the Medical Research Council Integrative Epidemiology Unit at the University of Bristol which is supported by the Medical Research Council and the University of Bristol (MC_UU_00011/1). Arthritis Research UK project grant (ref: 20244) supported the generation of adult reference statistical shape model. This publication is the work of the authors and MF will serve as guarantor for the contents of this paper. None of the funders had any influence on data collection, analysis, interpretation of the results, or writing of the paper.Peer reviewedPublisher PD

Mass spectrometry application on the detection of Sildenafil in aqueous phases

Sildenafil, the active ingredient of Viagra (Figure n.1), is a drug helpful in solving erectile dysfunction problems and recently entered the list of emerging contaminants. The use of these pharmaceuticals is increasingly widespread among perfectly healthy young people (20 or 30 years old) who make them a dangerous abuse for "recreational" purposes together with ecstasy: the result is a synergistic amplification of their final effects, such as the feeling of euphoria, confusion, disorientation, hallucinations, tremors or, in severe cases, irregular heartbeat and even coma. According to the 2018 annual report prepared by the Italian Medicines Agency (AIFA), this compounds’ consumption had increased over time from 2.9 DDD (Defined Daily Dose assumed per 1000 inhabitants in the referred year) in 2014 to 3.6 DDD in 2018. Unfortunately, it is impossible to detect the actual quantity used from the population (young and patients) because the internet network is becoming a way of purchasing to avoid medical prescriptions. Indeed, some researchers [1] report that illicit trading with pharmaceuticals products from the Internet is not wholly conscious of the risks for health concerning the quality of these products, such as the possible presence of toxic impurities [2]. The increase in demand is powering the illegal trade via the web, and, consequently, the risk of using an ineffective/harmful to health drug is very high [3,4]. The human body does not fully utilize these drugs. An unknown quantity, probably transformed, is excreted with urine and faeces. The high consumption of this substance, globally accomplished by legal and illegal ways, and the fact that Wastewater treatment plants (WWTP) cannot remove all types of contaminants that enter the sewer legitimates thinking that they can pose a severe threat to ecosystems and human health [5]. The unambiguous analytical determination of the active parent drug and the identification of its transformation products are therefore indispensable to try understanding if the quantity found of this drug in wastewater and surface water is linked to actual medical use and to verify whether tertiary purification treatments of wastewater are effective in the removal. In this work, the identification and quantification of this pharmaceutical product in water and synthetic wastewater were performed by LC-ESI-LTQ/MS and confirmed by CID-MSn. Thanks to high mass precision and MS/MS capability, determination and structural interpretation of sildenafil and its transformation products were achieved

SiPM and front-end electronics development for Cherenkov light detection

The Italian Institute of Nuclear Physics (INFN) is involved in the development of a demonstrator for a SiPM-based camera for the Cherenkov Telescope Array (CTA) experiment, with a pixel size of 6$\times$6 mm$^2$. The camera houses about two thousands electronics channels and is both light and compact. In this framework, a R&D program for the development of SiPMs suitable for Cherenkov light detection (so called NUV SiPMs) is ongoing. Different photosensors have been produced at Fondazione Bruno Kessler (FBK), with different micro-cell dimensions and fill factors, in different geometrical arrangements. At the same time, INFN is developing front-end electronics based on the waveform sampling technique optimized for the new NUV SiPM. Measurements on 1$\times$1 mm$^2$, 3$\times$3 mm$^2$, and 6$\times$6 mm$^2$ NUV SiPMs coupled to the front-end electronics are presentedComment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589