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In Naturally Occurring Asbestos (NOA) rich areas, water flows through asbestos bearing rocks and soils and generates waterborne fibres that may migrate in air and become a risk for humans. Research on the migration and dispersion after water vaporisation has been so far only marginally evaluated. This study investigates the migration in air of asbestos from a set of suspensions contaminated by chrysotile from Balangero (Italy), under controlled laboratory conditions. We evaluated i) the morphological modifications that might occur to chrysotile during migration from water to air, and ii) the amount of airborne chrysotile mobilised from standardised suspensions. Morphological alteration of asbestos fibres occurred during water-air migration and impacted on the analytical response of electron microscopy. Waterborne asbestos concentration higher than 40 ∙ 106 f/L generates in air concentration higher than 1 fibre per litre [f/L], the alarm threshold limit set by World Health Organization for airborne asbestos. A possible correlation between the waterborne fibre concentration as mass or number of fibres per volume unit [μg/L or f/L] was observed.

Groundwater or surface water flow into natural rock formations containing asbestos (NOA), e.g. serpentinites and metabasites, may result in water asbestos pollution. In fact, asbestos-bearing rocks weathering is the principal natural cause of fibres water-dispersion. As asbestos constitute a risk to human health, it is crucial, into NOA contexts, to verify the occurrence of mineral fibres in water resources, given their importance for agricultural and industrial activities and as a primary source for drinking water. For this purpose, the Lanzo Valleys and Balangero Plain (NW Italy) were selected as study area where to evaluate the possible occurrence of asbestos in groundwater, to correlate it to the geolithological and hydrogeological characteristics of the context and therefore to evaluate the possible mobility of asbestos in aquifers. The results of this preliminary study show the presence of asbestos in groundwater, generally occurring in very thin fibres which require TEM-EDS analysis. Water chemical characters, particularly dissolved cations, reflect the lithologies which occur in the area; concerning trace metals, only Ni shows a relation with NOA occurrence. In addition, several problems on sampling and analysis procedures are highlighted and discussed.

Large volumes of precious water resources are negatively affected by nitrate contamination, and the problem of the world population's exposure to this is becoming an even more pressing issue. To tackle this problem, the application of environmental isotopes has proven to be an effective method to identify the N origins and major transformations in different environments. In this work, nitrate (?15NNO3 and ?18ONO3) and boron (?11B) isotope analyses performed in the last twenty years in groundwater from shallow aquifers of the Po plain area, a complex hydrogeological system of European relevance, have been compiled in a comprehensive database together with major ionic contents; these data were integrated with additional original results, targeting areas not previously examined or complementing the available information. Such data, previously interpreted on the local scale, are examined at the Po plain scale, providing an understanding of the N sources and dynamics in the shallow aquifers, and defining the most important processes governing nitrate contamination in Northern Italy. The most impacted groundwater is that hosted in the alluvial fans of the Alpine and Apennine foothills, due to a combination of high soil permeability and presence of intensive agricultural activities. Here, aquifers are characterized by fast circulation and by great water table depths. On the contrary, nitrate contamination is absent in most low plain areas, with shallow water table depths but lower soil permeability, due to the presence of denitrification processes. The ?15N median values, calculated for each province, are significantly correlated with pig density. Hence, manure represents one of the main nitrate sources in groundwater from agriculture, the other being synthetic fertilizers. Isotopic compositions enriched due to denitrification are present in ~22% of the data, being responsible for nitrate abatement in groundwater affecting up to 70-80% of the original content. The B systematics, in such a low geogenic-B context, proved the presence in the investigated area of another anthropogenic nitrate source of civil origin (i.e. sewage). While new results on the local B sources are reported, the garnering of all groundwater data allowed us to define the range of the expected geogenic B signature (?11B = +13 ± 2.5?). This contribution is a significant step forward for the use of the coupled ?15N - ?11B toolbox in the study area, previously limited by a poor definition of the compositional end-members. This georeferenced set of hydrochemical and isotopic data will lay the foundations for future monitoring activities and advanced data treatment or modelling. In addition, since the hydrogeological setting of the investigated area shows common features to alluvial basins located near mountain ranges, the approach and the results presented in this study serve as a reference for other study areas worldwide.

Rainfall and temperature variability causes changes in groundwater recharge that can also influence groundwater quality by different processes. The aim of this study is the analysis of the hydrogeochemical variations over time due to meteorological variability in two different study areas in Italy: an alluvial aquifer in the Piedmont Po plain and an alluvial-pyroclastic aquifer in the Campanian plain. The examined plains show groundwater with natural quality not satisfying the European drinking water standards, or anthropogenic contamination. The peculiar natural quality is due, in the Campanian plain, to the closeness of volcanic areas, and to the presence of reducing conditions. In Piedmont plain a test site is characterized by a point-source contamination by heavy metals, due to the presence of past industrial activities. In all the examined areas there is a diffuse nitrate contamination. The fluctuations of the ions As, F, Fe, Mn, Cr VI, NO3, and Cl were analyzed and compared, using statistical methods, with the variations over time in precipitation, temperature, and piezometric levels, sometimes significant. Results highlight the importance of the groundwater and meteorological monitoring and the key role of the recharge variation in the hydrogeochemical processes. The linking degree between rainfall/temperature variability and hydrogeochemistry is variable, in function of the typology of chemical species, their origin, and of the aquifer characteristics. The fluctuation of climate variables determines sudden changes in the geochemistry of shallow unconfined aquifers (e.g., in the Piedmont plain), while semiconfined or confined aquifers (e.g., in the Volturno-Regi Lagni plain) react with a greater delay to these variations. Moreover, natural quality is more affected by climatic variations than anthropogenic contamination, which is the result of multiple environmental and anthropic factors.