The effect of grinding on tremolite asbestos and anthophyllite asbestos

The six commercial asbestos minerals (chrysotile, fibrous actinolite, crocidolite, amosite, fibrous tremolite, and fibrous anthophyllite) are classified by the IARC as carcinogenic to humans. There are currently several lines of research dealing with the inertisation of asbestos minerals among which the dry grinding process has received considerable interest. The effects of dry grinding on tremolite asbestos and anthophyllite asbestos in eccentric vibration mills have not yet been investigated. Along the research line of the mechanical treatment of asbestos, the aim of this study was to evaluate the effects of dry grinding in eccentric vibration mills on the structure, temperature stability, and fibre dimensions of tremolite asbestos from Val d\u2019Ala, (Italy) and UICC standard anthophyllite asbestos from Paakkila mine (Finland) by varying the grinding time (30 s, 5 min, and 10 min). After grinding for 30 s to 10 min, tremolite asbestos and anthophyllite asbestos showed a decrease in dehydroxylation and breakdown temperatures due to the increase in lattice strain and the decrease in crystallinity. Moreover, after grinding up to 10 min, tremolite and anthophyllite fibres were all below the limits defining a countable fibre according to WHO

Mineral Fibres

In the last decades, there has been increasing interest in Naturally Occurring Asbestos (NOA) and asbestos containing materials (ACMs) as a source of possible environmental risk. A crucial theme of interest related to environmental pollution is the enhanced mobilization of asbestos minerals affecting soils and rocks due to human activities (e.g., road construction, mining activity) in comparison with natural weathering processes. The volume has aimed to gather contributions and to compare results derived from various experiences of research groups regarding NOA minerals as a source of possible environmental risks for population. Case studies from various geological contexts are presented. Moreover, contributions presenting novel and classical approaches for ACM inertization and recycling, together with possible solutions for reducing asbestos exposure, has been also presented

The importance of prevention when working with hazardous materials in the case of serpentinite and asbestos when cleaning monuments for restoration

[Abstract]: Abstract: Health risks are often overlooked when the consequences are not evident in the short term. In restoration work, some activities can generate particles that may affect the health of workers through inhalation (e.g., cleaning of buildings or heritage artifacts composed of stone). Workers at quarries are also exposed to such materials and, therefore, the results of our work can help to increase the risk perception in workers from the stone sector, but also in construction workers in an environment associated with dust. To demonstrate the importance of protection to prevent health hazards, we laser-ablated some samples of serpentinite that contain serpentine minerals as major phase minerals. The powder obtained in filters coupled to the ablation laser was analysed, using tools such as an optical microscope, X-ray powder diffraction, a transmission electron microscope and thermal analysis. The results were very didactic, and the intention is to use them, by way of graphics and diagrams, to build information security sheets that will alert workers to the need of using masks when working, or to use tools with coupled filters such as the one used for our study. The main goal is to demonstrate that the interdisciplinary combination of scientific approaches can be used for the sake of human health.Universidad de Salamanca; 2016/00218/001Ministerio de Ciencia e Innovación; PID2021-123948OB-I00Italia. Ministero dell'Università e della Ricerca; 20173 x 8WA

Results from KLOE at DAFNE

The KLOE experiment at the Frascati φ factory, Daφne, has collected ~500 pb -1, i.e. 1.5 × 10^9 φ decays. At the φ factory it is possible to select pure KL and KS beams. Although the integrated luminosity is insufficient for precision tests of the CP, T symmetries in kaon decays, a wide number of topics in kaon and hadronic physics are accessible from the largest sample of φ decays at rest collected so far. The cross section σ(e+e- --> π+π-γ) below 1 GeV, relevant for the precise evaluation of the muon magnetic moment, has been measured with a statistical accuracy better than 1%. For the KS, we obtained the ratio of the branching fractions Γ(KS --> π+π-(γ))/Γ(KS --> π0π0) = (2.239 +/- 0.003stat +/- 0.015syst), fully inclusive of the ππγ final state. The analysis of the ~20,000 KS semileptonic decays KS --> πeν is being finalized providing precise measurements of both, the KS semileptonic branching ratio, and Re x+, i.e. the ΔS = ΔQ rule violation parameter. For the KL, we obtained the ratio Γ(KL --> γγ)/Γ(KL --> π0π0π0) = (2.80 +/- 0.02stat +/- 0.02syst) × 10-3, of interest to Chiral Perturbation Theory (ChPT), as well as preliminary results on the branching ratios to other decay modes. In particular, our measurements of the semileptonic decays of both, neutral, and charged kaons will improve the precision of the CKM matrix element |Vus|, clarifying the present disagreement between different experiments. The φ radiative decays, both in scalar and pseudo-scalar mesons, have been analyzed giving new measurements of the ɛ - ɛ' mixing angle, and of the φ --> a0(980)γ, φ --> f0(980)γ branching ratios

Potentially toxic elements (PTEs) associated with asbestos chrysotile, tremolite and actinolite in the Calabria region (Italy)

[EN]Potentially toxic elements (PTEs) hosted in asbestos elongate mineral particles is one of the factors that determines their toxic/pathogenic effects. This study quantifies and compares these elements in terms of major, minor and trace element concentrations (Si, Mg, Ca, Al, Fe, Mn, Cr, Co, Ni, Cu, Zn, Be, V, As, Rb, Sb, Ba, Pb, Sr) in various types of asbestos using micro X-ray fluorescence (μ-XRF) and inductively coupled plasma mass spectrometry (ICP-MS), in order to understand how they contribute to asbestos-related diseases. Chrysotile, tremolite asbestos and actinolite asbestos extracted from the Gimigliano-Mount Reventino Unit (Calabria Region, Southern Italy) were used for this study. In the minerals analysed, high concentrations of Cr (171 ppm) and Be (2.9 ppm) were found in tremolite asbestos and chrysotile respectively. When calculating the pseudo-total concentrations of trace elements in the samples, the largest amounts were detected in tremolite asbestos, followed by actinolite asbestos and chrysotile. However, since other metals such as Mn and Fe (minor elements) are known to induce toxicity, and considering their input to the overall balance, actinolite contained the largest amount of PTEs and in this case chrysotile proved to be more toxic than tremolite asbestos. Furthermore, the potential leaching of PTEs, released by chrysotile, tremolite and actinolite asbestos-containing rocks, into the soil and water supply is also discussed. Since asbestos elongate mineral particles can be widespread in the environment (i.e. air, rocks, soil, water), it is essential to quantify the toxic elements present in asbestos elongate mineral particles in order to prevent asbestos-related diseases. The knowledge obtained from this study will provide us with a better understanding of asbestos-related lung cancer.GIR CHARROC

Chemical reactivity of thermal treated naturally occurring amphibole asbestos

Non-occupational (environmental) exposure to naturally occurring asbestos (NOA) represents a potentially important source of risk for human health in several parts of the world. Chemical reactivity of fibres surface is one of the most relevant physical-chemical property to asbestos toxicity and is commonly associateci to the presence of Fe at the surface, and in particular to its coordination and oxidation state. However, no detailed information is still available about dependence of chemical reactivity on surface iron topochemistry, which is the basis for defining structure-activity relationships. In this work the chemical reactivity of two amphibole asbestos samples, UICC crocidolite from Koegas Mine, Northern Cape (South Africa) and fibrous tremolite from Montgomery County, Maryland (USA), was investigateci after sample heating up to 1200 °c. Ex-situ X-ray powder diffraction (XRPS and the Rietveld method), scanning (SEM) and transmission (TEM) electron microscopy were used for characterizing the minerai fibres before and after the thermal treatment. In addition, thermal stability of the of the amphibole asbestos was analysed in-situ by TG/DSC. Two conventional target molecules (H202 and Hcoo-) and the DMPO spintrapping/ EPR technique were used to measure the radical activity of both pristine and thermal treated samples. Results show that, after thermal treatment, both amphibole asbestos are completely converted into hematite, cristobalite and pyroxene, stili preserving the originai fibrous morphology (pseudomorphosis). Notably, in spite of the thermal decomposition, the heated samples show a radical production comparable to that of the pristine ones

Naturally occurring asbestos in quarries: southern Spain as a case study

[EN]The Nevado-Filábride Complex (NFC) area (southern Spain) is well known for the widespread mining and quarrying activities. Serpentinite and metabasite rock types are extracted, processed and traded as building and ornamental stones. Due to possible presence of Naturally Occurring Asbestos (NOA) minerals in these lithotypes, the aim of the investigation of this paper is to discern about the presence of these fibrous minerals and to characterize them in detail. In order to do this, seven serpentinite rock samples were collected in four quarries located in Sierra Nevada and Sierra de los Filabres (South-eastern Spain) and studied by X-ray powder diffractometry (XRPD), Scanning Electron Microscopy combined with Energy-Dispersive Spectrometry (SEM/EDS), Differential scanning calorimetry (DSC), Derivative Thermogravimetry (DTG) and by X-ray Synchrotron microtomography (SR-µCT). The investigation of asbestos minerals is very important not only from a scientific point of view, but also from a legislative one, especially for the administrative agencies that have to take decisions with regards to the implementation of health protection to workers (e. g., quarry excavations, road yards, civil constructions, building stones).GIR CHARROC

A new calculation of atmospheric neutrino flux: the FLUKA approach.

Abstract Preliminary results from a full 3-D calculation of atmospheric neutrino fluxes using the FLUKA interaction model are presented and compared to previous existing calculations. This effort is motivated mainly by the 3-D capability and the satisfactory degree of accuracy of the hadron-nucleus models embedded in the FLUKA code. Here we show examples of benchmarking tests of the model with cosmic ray experiment results. A comparison of our calculation of the atmospheric neutrino flux with that of the Bartol group, for E ν > 1 GeV, is presented

Mineralogical and Geochemical Characterization of Asbestiform Todorokite, Birnessite, and Ranciéite, and Their host Mn-Rich Deposits from Serra D'Aiello (Southern Italy)

Manganese ores, especially the oxyhydroxides in their different forms, are the dominant Mn-bearing minerals that occur in marine and terrestrial environments, where they are typically found as poorly crystalline and intermixed phases. Mn oxyhydroxides have a huge range of industrial applications and are able to exert a strong control on the mobility of trace metals. This paper reports the results of a detailed study on the Mn oxyhydroxides occurring in the manganiferous deposit outcropping in the Messinian sediments from Serra D'Aiello (Southern Italy). Nine Mn samples were characterized in detail using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermogravimetry (TG), transmission electron microscopy combined with energy dispersive spectrometry (TEM/EDS), and X-ray fluorescence (XRF). The results indicated that the Mn deposit included the oxyhydroxide mineral species birnessite, todorokite, and rancièite. The size, morphology, and chemical composition of Mn oxyhydroxide samples were investigated in order to define their impact on the environment and human health. Todorokite displayed asbestiform shapes and could disperse fibers of breathable size in the air. Furthermore, since in-depth characterization of minerals within Mn deposits may be the first step toward understanding the genetic processes of manganese deposits, hypotheses about the genesis of the Mn oxyhydroxide deposits were discussed