The abandoned antimony-mines of SE Sardinia: impact on surface waters

This study investigates the impact of abandoned Sb-mines on the Flumendosa River, which is the most important water resource in southern Sardinia. Hydrogeochemical surveys carried out in 2005 and 2006 indicated a significant impact of waters flowing out from adits, slag, tailings and waste materials on surface waters. The contaminated waters show alkaline pH, and high dissolved SO4, Sb and As (up to 1900, 9.6 and 3.5 mg/L, respectively). Although the flow rates of drainages from the mining area are usually low (in the range of < 0.1 to 1 L/s), the contribution to dissolved concentrations of Sb in the streams downstream of mines is high. Sampling under high flow conditions in the Flumendosa River before the confluence with the contaminated streams showed Sb concentrations below the limits established by the guidelines of World Health Organization for drinking water (i.e. 20 g/L), while downstream of the confluence dissolved Sb was 32 g/L. Contamination in the Flumendosa extended 16 km, and attenuation (15 g/L Sb) was only observed close to the Flumendosa mouth

Enargite by XPS

X-ray photoelectron spectroscopy was used for characterizing the enargite surface. Freshly cleaved samples were analyzed at liquid nitrogen temperature. Enargite is a copper arsenic sulfide of formula Cu3AsS4; it is used as a minor ore of copper. Enargite is a potential source of arsenic and may create environmental problems through the release of toxic elements upon oxidatio

Comparison of Pre- and Post-Remediation Stream Water Chemistry in the Arsenic-Contaminated Baccu Locci Mine Watershed (Italy): Preliminary Data

AbstractEnvironmental issues related to past mining activities have become the subject of public interest only in the last 20-25 years. Consequently, experience related to the mitigation and control of environmental pollution in mining areas is a recent development. The existing methods of remediation are often partially ineffective, especially when applied without an in-depth geochemical and mineralogical study of the site. This paper reports on preliminary data concerning the effect of remediation actions in an arsenic-contaminated mine watershed (Baccu Locci mine – Italy) a few months from its completion. The persistence of the pre-remediation conditions raises some doubt on the effectiveness of the undertaken remediation actions, even if more time is certainly needed to reach a new environmental steady state. Much remains to be learned about mistakes and successes of mine site remediation, and the monitoring of the Baccu Locci area represents an opportunity to acquire new fundamental knowledge on this issue

A methodological approach for the identification of sulphate sources in the Portoscuso area (south-western Sardinia)

Several detrimental effects due to intense industrial activities affect the groundwater of the Portoscuso area (SW Sardinia, Italy) such that the Italian Government has designed the whole territory as a contaminated site of national interest (D.M., March 12, 2003). Groundwater pollution is a crucial environmental issue in this area, where a volcanic ignimbrite succession up to 500 m thick outcrops, locally covered by sand deposits of variable thickness. Groundwater upgradient to the industrial district shows sulphate concentrations exceeding the background value of 450 mg/L calculated for the area (Vecchio et al., 2011). In order to verify the origin of sulphate, multidisciplinary investigations were carried out on the geochemical features and stable isotope ratios in groundwater

High-density lipoprotein contribute to G0-G1/S transition in Swiss NIH/3T3 fibroblasts

High density lipoproteins (HDLs) play a crucial role in removing excess cholesterol from peripheral tissues. Although their concentration is lower during conditions of high cell growth rate (cancer and infections), their involvement during cell proliferation is not known. To this aim, we investigated the replicative cycles in synchronized Swiss 3T3 fibroblasts in different experimental conditions: i) contact-inhibited fibroblasts re-entering cell cycle after dilution; ii) scratch-wound assay; iii) serum deprived cells induced to re-enter G1 by FCS, HDL or PDGF. Analyses were performed during each cell cycle up to quiescence. Cholesterol synthesis increased remarkably during the replicative cycles, decreasing only after cells reached confluence. In contrast, cholesteryl ester (CE) synthesis and content were high at 24h after dilution and then decreased steeply in the successive cycles. Flow cytometry analysis of DiO-HDL, as well as radiolabeled HDL pulse, demonstrated a significant uptake of CE-HDL in 24h. DiI-HDL uptake, lipid droplets (LDs) and SR-BI immunostaining and expression followed the same trend. Addition of HDL or PDGF partially restore the proliferation rate and significantly increase SR-BI and pAKT expression in serum-deprived cells. In conclusion, cell transition from G0 to G1/S requires CE-HDL uptake, leading to CE-HDL/SR-BI pathway activation and CEs increase into LDs

Combining HLA-DRB1-DQB1 and <i>Mycobacterium avium subspecies paratubercolosis</i> (MAP) antibodies in Sardinian multiple sclerosis patients: associated or independent risk factors?

Background: Amongst Sardinians the human leukocyte antigen (HLA) DRB1-DQB1 haplotypes *15:02-*06:01, *16:01-*05:02, *14:01-4-*05:03 are protective for multiple sclerosis (MS), while *13:03-*03:01, *04:05-*03:01, *03:01-*02:01, *15:01-*06:02 and Mycobacterium avium subspecies paratubercolosis (MAP) are predisposing factors. We studied the correlation between MAP and HLA. Methods: Five hundred thirty-one patients were searched for anti-MAP2694 antibodies, DRB1-DQB1 genotyping was performed. The haplotypes were classified as predisposing, neutral or protective. Results: Anti-MAP2694 were found in 23 % of subjects carrying one protective HLA versus 32 % without (p = 0.04). Conclusions: We showed a lower frequency of Abs in patients with protective HLA. These haplotypes could have a protective role for both MS and MAP

Quality of life perception in type 2 diabetes

Purpose: Lifestyle analysis is often used for primary and secondary prevention in many chronic metabolic diseases, including diabetes. Questionnaires are simple and common methods for first investigation risk of factors related to the perception of quality of life (QoL). The present study evaluates the feasibility to use questionnaires for first investigation of risk factors, and ascertain whether the results of such questionnaires are associated with the perception of QoL. Methods: Validated questionnaires from the international ACSM guidelines were used to study a cohort of 142 consecutive type 2 diabetes patients (mean age: 66.1 years ± 10.9). Results: QoL perception was normal; BMI was compatible with overweight in 79.1% of subjects, and obesity in 20.9%. Cognitive abilities decreased with age and low consumption of dried fruit and legumes. There was evidence of a statistically significant association between BMI and QoL (rho = -0.18; p = 0.03). Conclusions: Questionnaires are useful to assess lifestyle habits and highlight risks factors. Poor knowledge of patients’ own chronic disease may contribute to a negative impact in diabetes

Natural attenuation can lead to environmental resilience in mine environment

Four streams flowing in the Iglesiente and Arburese mine districts (SW Sardinia, Italy), exploited for zinc (Zn) and lead (Pb) extraction from sulphides and secondary non-sulphide mineralization (calamine ores), have been studied combining investigations from the macroscale (hydrologic tracer techniques) to the microscale (X-ray powder diffraction, scanning electron microscopy, X-ray absorption spectroscopy). In the investigated area, concerns arise from release of metals to water during weathering of ore minerals and mine-waste. Specifically, Zn is observed at extremely high concentrations (10s of mg/L or more) in waters in some of the investigated catchments. The results from synoptic sampling campaigns showed marked differences of Zn loads, from 6.3 kg/day (Rio San Giorgio) to 2000 kg/day (Rio Irvi). Moreover, natural attenuation of metals was found to occur i) through precipitation of Fe compounds (Fe oxy/hydroxides and “green rust”), ii) by means of the authigenic formation of metal sulphides promoted by microbial sulphate reduction, iii) by metal intake in roots and stems of plants (Phragmites australis and Juncus acutus) and by immobilization in the rhizosphere, and iv) by cyanobacterial biomineralization processes that lead to formation of Zn-rich phases (hydrozincite and amorphous Zn-silicate). The biologically mediated natural processes that lead to significant abatement and/or reduction of metal loads, are the response of environmental systems to perturbations caused from mine activities, and can be considered part of the resilience of the system itself. The aim of this study is to understand the effect of these processes on the evolution of the studied systems towards more stable and, likely, resilient conditions, e.g. by limiting metal mobility and favouring the improvement of the overall quality of water. The understanding of how ecosystems adapt and respond to contamination, and which chemical and physical factors control these natural biogeochemical barriers, can help to plan effective remediation actions