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This contribution describes a geodatabase structure designed to manage a large amount of geo-environmental data for the "Gronda di Genova" highway by-pass tunnels in Liguria region (Italy). In particular, an innovative dataset structure founded on an explicit conceptual model was designed to represent the distribution of petrofacies containing Natural Occurring Asbestos (NOA), and their minero-chemical composition. This in order to assess the environmental risk (air dispersion of fibers) due to the tunnel excavation in the asbestos-bearing rocks. Problems related to the GIS (shp) - AutoCAD (layer) conversion have been also considered for delivering the graphic layout of the project and are here discussed.

The presence of naturally occurring asbestos (NOA) in many areas worldwide requires an enhanced geological risk evaluation to ensure workplace safety from asbestos during large construction projects. Due to the complexity of the geological risk definition, health and safety regulations for working with asbestos-bearing materials are often not enforceable in NOA settings. Therefore, to correctly estimate the risk of NOA in these scenarios, new procedures are urgently needed to provide (1) a detailed geological model representative of the possible presence of the asbestos, (2) representative sampling, and (3) a reliable quantitative determination of asbestos content in rocks. This work aims to discuss the improvements on the two latter points specifically developed during the design of the “Gronda di Genova” project, a 50-km-long tunnel bypass partially designed in the NOA-bearing meta-ophiolites of the Ligurian Alps and ophiolites of the northern Apennines in Italy. Implementation of Gy's theory on sampling was used to maintain statistical validity during sample processing from the primary sample to the analytical sample and is here described. The scanning electron microscopy/energy dispersive spectroscopy procedure for the quantification of NOA was improved with an error analysis delivering the minimum number of fibers to be measured to achieve the best analytical results.

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.

Asbestos may constitute a severe health risk when meta-ophiolites are excavated for large infrastructural projects. For public acceptance, a reliable estimation of the content of Naturally Occurring Asbestos (NOA) is necessary for the design of construction sites, workers' safety and spoil management. In the framework of a research project supporting the final design of a highway tunnel system in NW Italy, SEM-EDS (Scanning Electron Microscopy – Energy-Dispersive Spectrometry) quantitative analyses were performed to provide a direct NOA content estimation by counting and weighing the asbestos fibers in the rocks, after a chemical and geometrical characterization. The direct NOA content estimation was compared with an indirect estimation obtained through a fracture network modeling based on a structural survey on a selected outcrop and statistical analysis of a relative digital image. The fracture intensity, inferred from the fracture network model, was multiplied by coefficients deriving from the semi-quantitative estimation of the geological relations between asbestos mineral occurrence and fracture size, thickness and distribution. A good agreement between the indirect NOA estimation and the average result of the SEM-EDS analysis was obtained. Thus, the statistical analysis of the fracture network may represent a valuable support to the SEM-EDS quantitative analysis based on mineral fibers counting. However, the quality of the indirect NOA estimation depends on the postulates for inferring the coefficients describing the distribution and occurrence of the asbestos minerals within the fractures. This Note discusses the above-mentioned issues, as well as those concerning the procedure for a representative sampling of NOA-bearing rocks and fractures.

Naturally-Occurring Asbestos (NOA) may constitute a severe health risk when metamorphic rocks are excavated for large infrastructure projects. For public acceptance, a reliable assessment of the content of NOA is necessary for the design of the construction site, workers’ safety, and spoil management. Direct measurements of NOA content can be made by SEM-EDS analyses on an adequate number of samples. Such measurements are sufficiently precise but questions about the representativity of the samples may arise, especially when the rock units are structurally and lithologically complex. Therefore, in order to corroborate the direct assessments, alternative and indirect assessments can be performed by measuring the fracture volumetric porosity, provided that almost all the NOA is deposited as veins in the fractures of the rock mass. Statistical sampling and inference procedures can be applied to derive such an index. In this paper, an indirect assessment of NOA is reported and compared with the assessment obtained by direct measurements. The application is to a metamorphic rock formation through which a tunnel is to be driven as part of the ”Gronda di Genova” highway development in Genoa, Italy. Even though significant approximations are made, the indirect assessment is relatively close to the direct measurement.

For a reliable evaluation of the geo-environmental risk due to naturally occurring asbestos (NOA) during rock excavation of large infrastructure projects, a proper procedure is needed. First, it is necessary to provide a detailed geological model tailored to the NOA-related issues that should drive the rock sampling procedures in order to obtain a representative sampling. The sampling procedures should take into account lithological variability and relative spatial distributions of the rock units. The geological model for NOA should be thus constrained by the main NOA petrofacies occurring in a given geotectonic context, which take into consideration both the mineralogical and structural features, and the identification of NOA homogeneous zones in which the NOA petrofacies are distributed. In this paper, some geo-environmental problems faced during the excavation, in meta-ophiolites, of a long highway tunnel are described. The geological model of the complex setting of the tunnel area (northern Italy, Alps-Apennines junction) is described, focusing on how the NOA-related problems were addressed to allow reliable and detailed estimations of NOA contents for each NOA homogeneous zone and the relevant tunnel layout segment.

Naturally-Occurring Asbestos (NOA) may constitute a severe health risk when metamorphic rocks are excavated for large infrastructure projects. For public acceptance, a reliable assessment of the content of NOA is necessary for the design of the construction site, workers' safety, and spoil management. Direct measurements of NOA content can be made by SEM-EDS analyses on an adequate number of samples. Such measurements are sufficiently precise but questions about the representativity of the samples may arise, especially when the rock units are structurally and lithologically complex. Therefore, in order to corroborate the direct assessments, alternative and indirect assessments can be performed by measuring the fracture volumetric porosity, provided that almost all the NOA is deposited as veins in the fractures of the rock mass. Statistical sampling and inference procedures can be applied to derive such an index. In this paper, an indirect assessment of NOA is reported and compared with the assessment obtained by direct measurements. The application is to a metamorphic rock formation through which a tunnel is to be driven as part of the "Gronda di Genova" highway development in Genoa, Italy. Even though significant approximations are made, the indirect assessment is relatively close to the direct measurement.

Realization of large geo-engineering projects in rocks containing naturally occurring asbestos (NOA) must address several crucial geo-environmental issues, including the design of the construction site, the enforcement of health protection measures and the environmentally responsible spoil management. This leads to a compelling need to develop effective and standard procedures to evaluate the distribution and concentration of NOA in rock volumes. NOA petrofacies are here proposed as an innovative tool to evaluate the asbestos distribution and concentration in complex geological settings. NOA petrofacies are fundamental asbestos-bearing rock types, consisting in recurrent lithological and structural features controlling asbestos occurrence. Here we describe and discuss how the NOA petrofacies approach was utilized in a geo-environmental study for the evaluation of asbestos content in a complex meta-ophiolite suite, which will be crossed by the “Gronda di Genova” highway by-pass project (Genoa, NW Italy). NOA petrofacies were used to predict the distribution and relative abundance of NOA in geologically homogeneous zones characterized by the occurrence of specific NOA minerals.

Among asbestos minerals, fibrous riebeckite (crocidolite) and tremolite share the amphibole structure but largely differ in terms of their iron content and oxidation state. In asbestos toxicology, iron-generated free radicals are largely held as one of the causes of asbestos malignant effect. With the aim of clarifying i) the relationship between Fe occurrence and asbestos surface reactivity, and ii) how free-radical generation is modulated by surface modifications of the minerals, UICC crocidolite and fibrous tremolite from Maryland were leached from 1 day to 1 month in an oxidative medium buffered at pH 7.4 to induce redox alterations and surface rearrangements that may occur in body fluids. Structural and chemical modifications and free radical generation were monitored by HR-TEM/EDS and spin trapping/EPR spectroscopy, respectively. Free radical yield resulted to be dependent on few specific Fe2+ and Fe3+ surface sites rather than total Fe content. The evolution of reactivity with time highlighted that low-coordinated Fe ions primarily contribute to the overall reactivity of the fibre. Current findings contribute to explain the causes of the severe asbestos-induced oxidative stress at molecular level also for iron-poor amphiboles, and demonstrate that asbestos have a sustained surface radical activity even when highly altered by oxidative leaching.

In many urban and natural areas, the presence of naturally occurring asbestos (NOA) requires a geological risk evaluation to enforce safety and exposure monitoring during the achievement of surface and subsurface infrastructures. A set up of proper procedures must provide: (i) a detailed geological model of the possible presence of the asbestos, (ii) a representative sampling, (iii) a correct analytical approach, and (iv) a working procedure that can be efficiently applied during excavation activities. At present, the EU regulations for a safety work in asbestos-bearing materials are still not exhaustive because of the great complexity of the matter and uncertainties in geological risk definition. This paper presents two case studies where the different involved parties (scientific community, environmental agencies, and private companies) jointly contributed to find technical solutions for a correct risk management of excavations in asbestos-bearing rocks as well as reliable analytical procedures for quantitative determination of the fibre content.

The European INCO-DEV BOMOSA Project (Integrating BOMOSA cage fish farming systems in reservoirs, ponds and temporary water bodies in Eastern Africa) intends to establish small scale fish farming in marginal water bodies in Kenya, Uganda and Ethiopia, creating rural aquaculture networks with the aim to economically integrate aquaculture with agriculture. In order to study veterinary and public health aspects in Bomosa fish farming systems, a parasitological survey on wild and cultured tilapias (Oreochromis niloticus niloticus) has been carried out from March 2007 to October 2008. A total of 982 tilapias - 685 from Kenya, 222 from Uganda and 75 from Ethiopia - were sampled and subjected to complete parasitological examination. During the survey, fish from different environments (258 from open water reservoirs, 445 from ponds and 279 from BOMOSA cages) were sampled in order to evaluate the factors which could influence the parasite diffusion and outbreak of diseases. Quantitative data, such as prevalence, intensity and abundance, and qualitative data are presented together with the main abiotic and biotic risk factors identified as relevant for veterinary and public health aspects in tilapia aquaculture.

A natural deactivation of chrysotile asbestos occurs on serpentinite rocks where lichens selectively grow on the fibres and secrete metabolites, including oxalic acid, which, in the long term, turn the fibres into a non-toxic amorphous material.

A 20-μg dose of a recombinant hepatitis B vaccine was given at 0, 1, 2 and 6 months to 24 hemodialysis patients. From month 7 (i.e., 1 month after the fourth injection), 58.3% (14/24) of the patients had developed protective levels of antibodies against hepatitis B surface antigen (anti-HBs). In patients responding to vaccination, the fourth injection led to an abrupt rise of the anti-HBs titres which reached their maximum 2 months later, that is, in month 8. At that time, the geometric mean titre of anti-HBs was 145.79 mlU/ml. Eighteen months after the start of vaccination, 50% (12/24) of the patients were maintaining protective levels of anti-HBs antibodies. It is noteworthy that these results could be obtained with a considerably lower dosage than previously recommended.