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Naturally Occurring Asbestos (NOA) has drawn the attention worldwide when investigation revealed an increased incidence of malignant mesothelioma in population living near NOA sites. In Basilicata region (South Italy), population living in the villages of Castelluccio Superiore and Inferiore, Lauria, Latronico, Episcopia, San Severino Lucano, and Francavilla in Sinni may be considered at high risk of asbestos exposure because these villages are either surrounded by or built on NOA-rich ophiolitic outcrops. In this work we investigated an asbestos tremolite sample coming from the ophiolitic rocks outcropping in the quarry of Iacolinei, widely used in the past to extract aggregates for various applications.  A detailed mineralogical characterization has been attained by using a multi-analytical approach (EMPA, SEM-EDS, TEM-EDS, Mössbauer, µ-Raman, X-ray powder diffraction, and thermal analysis). Morphological investigation highlighted that the sample is composed of long fibers (> 5 µm) with a significant fraction (ca. 55%) having width below 0.25 µm, considered the most biologically active fibers. Moreover, the crystal chemical characterization showed that Fe occurs at the octahedral sites of the tremolite structure. It should be noted that Fe plays a primary role in the toxicity of asbestos. Based on these results, the investigated asbestos tremolite may be considered a potent mesothelial carcinogen, requiring therefore special attention for public health protection purposes. Investigations using sentinel animals to assess the diffusion of the tremolite fibers into the environment from the serpentinite rocks and soils of Iacolinei quarry are in progress., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

In Calabria (Southern Italy) naturally occurring asbestos (NOA) mainly occurs in the ophiolitic sequences cropping in the Mount Reventino area. The most common type of asbestos detected was the amphibole tremolite; fibrous antigorite and minor chrysotile were also found. The development of asbestos-related diseases depends on, among other things, the morphological characteristics of fibers, length and width, affecting the durability of asbestos fibers in the lung. In this work fifteen lung samples of sheep, goats and wild boars, grazing around the Mount Reventino area were collected and asbestos fibers analysed. Observed fibers (357), of which 97 % were tremolite and 3 % antigorite fibers, were grouped according to species, grazing area and age of the animals. The aim of this work was to highlight any differences among the groupings and to compare our size results with data in literature related to exposed populations. Principal Component Analysis (PCA) highlighted a positive correlation between tremolite fiber length and width and revealed groupings in terms of animal age. The Kruskal-Wallis test showed statistically significant differences between fiber mean widths in young and old animals. 63 % observed asbestiform fibers were longer than 5 μm and 7 % of the fibers were longer than 20 μm (critical fiber length connected to the frustrated phagocytosis by the macrophage). Fibers conforming to the Stanton Hypothesis size (predictor of the carcinogenic potency of fibers) were 1 %. Our size parameters of fibers detected in the animal lungs were in fairly good agreement with literature data for human asbestos exposure to tremolite. These results confirmed that an animal-sentinel system could be used to monitor the natural background of the airborne breathable fibers exposure. In addition, the size correlation of animal-human breathed fibers could be useful to study their potential toxicity. Additional data are necessary for improving the agreement with human exposure data., Competing Interests: Declaration of competing interest The authors declare that have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Asbestos fibre counting by phase-contrast microscope is subject to many sources of variation, including those dependent on the analyst. In this study, asbestos sample slides prepared with relocatable coverslips have been used for fibre counting among voluntary analysts to evaluate their proficiency. One slide of amosite and one of chrysotile were distributed to all the analysts, and three proficiency testing rounds were conducted for amosite and four for chrysotile. Each relocatable coverslip has a report in which are reported for each viewing field both the number of certified fibres (Verified Fibres) and a drawing representing the shape and position of the individual fibres. In the first round, the analysts were asked to report only the number of fibres counted in each of the predesignated fields of view. In the other rounds, subsequently developed, the analysts had to report the number and the position of the fibres for each field. The reported number of fibres and their position in each of the designed fields were evaluated against their respective verified fibres, to identify types of error. Discrepancies between reported fibres and verified fibres in each field of view have been used to evaluate the proficiency of the analysts. The discrepancies can be positive (D+) or negative (D-) depending on whether the analyst counts, for a specific field of view, more or less fibres compared to the verified fibres. The score is calculated using the following equation: Score = (1 - ∑D+ + ∑│D-│/VF) × 100. An analyst obtaining a score of ≥60, which corresponds to (∑D+ + ∑│D-│)/VF ≤ 0.40, is proficient. The number of laboratories that participating in this study varied from 13 to 17 depending on the rounds. For amosite fibre counts, the results were generally good compared to a proficiency score of 60. The major error made by analysts was the counting of fibres shorter than 5 µm, where this error was of 62% of extra fibres and accounted for 8% over-estimation of amosite fibres. For chrysotile, a score of ≥50 has been used to consider an analyst as proficient. The results of chrysotile fibres showed that in the first round all analysts counted less than fifty per cent of the verified fibres. In the second round 10 analysts out of 13 reached a score of ≥50, 8 of 16 in the third and 10 of 12 in the fourth. For chrysotile fibres, the error relating to the counting of fibres shorter than 5 µm was of 56% of extra fibres, but the error that most influenced the results was the number of oversight-missing fibres. This type of error accounted for 97% of the missing fibres and for the 29% under-estimation of the chrysotile fibres. For amosite fibre counting, results of this study show an improvement of the analyst's performance. For the chrysotile fibre count, although there is a significant improvement in the comparison between some rounds, this is not continuous over time., (© The Author(s) 2021. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.)

Ophiolites are known sources of naturally occurring asbestos (NOA). In Calabria (Southern Italy) NOA are mainly concentrated in the ophiolitic sequences cropping in the Mount Reventino area, in the southern part of the Sila massif, and along the Coastal Chain. The most common type of asbestos identified in the rocks of these areas belongs to the tremolite-actinolite series. Another identified asbestiform mineral is fibrous antigorite belonging to the serpentine mineral group with a minor amount of chrysotile. The purpose of the present study is to evaluate the diffusion of natural asbestiform fibers from NOA using sentinel animals. Fifteen lung samples of sheep, goats and wild boars from Mount Reventino area and two from an area free from NOA were collected. The lung samples were subjected to anatomopathological examination and lung fiber burden analysis by electron microscopy. Abundant tremolite and few antigorite fibers were detected in the lung samples coming from the NOA area. No corpuscle of asbestos was observed. No fiber was found in the two lung samples of sheet from the area free from NOA. These concentrations of fibers per gram of dry weight of lung tissue (f/gdw) ranged from 10 4 to 10 6  f/gdw. The asbestos fibers detected in the lungs of the examined animals reflect the geological features of the areas where they grazed and lived. The anatomopathological analysis showed that 60% of the examined animals had macroscopic lesions affecting their lungs. The presence of tremolite fibers in the lungs confirms the diffusion of mineral fibers in the environment and the real advantage of using animal populations in the study areas., Competing Interests: Declaration of competing interest The authors declare that have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objectives: to estimate the health impact of asbestos fibres naturally occurring in Mount Pollino area (Basilicata Region, Southern Italy)., Design: geographic mortality, hospitalization, and incidence study. Setting and participant s: population resident in 12 Municipalities of Mount Pollino area with naturally occurring asbestos fibres., Main Outcome Measures: standardized mortality ratio (SMR) and standardized hospitalization rate (SHR) for asbestos-related diseases; standardized incidence ratio (SIR) for mesotheliomas. Result s: in the area of Mount Pollino, where asbestos fibres naturally occur, especially in the sub-area in which fibres are close to dwellings and settlements, it was observed: • a significant excess of mesothelioma incidence (SIR: 208; CI95% 111-355; 13 observed); • a non-significant excess of hospitalization for malignant pleural neoplasms (SHR: 176; CI95% 93-335; 9 observed); • a significant excess for mortality and hospitalization for pneumoconiosis (SMR: 534; CI95% 345-824; 20 observed - SHR: 245; CI95% 149-405; 15 observed); • a significant excess for hospitalization (SHR: 852; CI95% 290-2,506; 3 observed) for asbestosis., Conclusion: it is necessary to continue environmental monitoring and environmental remediation in the area with higher asbestos exposure. It is suggested to implement a permanent process of epidemiological surveillance in this same area. A communication plan with local administrators, general practitioners, school teachers, media, and the resident population at large should be realized.

Introduction: The town of Biancavilla (Sicily) was included in the National Priorities List of Contaminated Sites due to environmental dispersion of amphibole fibers owing to the extraction of materials from a local quarry. The present report summarizes results from several, hitherto unpublished, environmental surveys carried out in the area, as well as from published analyses of the chemistry and composition of fibers., Methods: Data included here comprises environmental fiber concentrations by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) analysis in soil, indoor and outdoor air, personal monitoring, as well as a chemical characterization of the fibers. The full chemical structure and spectroscopic characterization of fibers were obtained through a multi-analytical approach: SEM-EDS, X-ray powder diffraction (XRPD), as well as Mössbauer (MS) and Fourier transform infrared (FT-IR) spectroscopies., Results: Data analyzed provided a spatial and temporal picture of fiber concentrations in Biancavilla, and a qualitative assessment of population exposure. Results suggest that until 2000, the population had been exposed to high levels of amphibole fibers. Mitigation measures adopted since 2001, gradually reduced exposure levels to about 0.1-0.4 ff/l. Previous studies on fibrous amphiboles from Biancavilla reported considerable chemical variability. Differences in composition, especially concerning the presence of Si, Ca, Fe, and Na, were found both within and between samples. Compared to the previously investigated prismatic fluoro-edenite, these fibrous fluorine amphiboles consistently showed higher average values of Si and Fe content, whereas Ca was significantly lower, which we consider a distinctive characteristic of the fluorine fibrous variety., Conclusions: The population of Biancavilla had been highly exposed to a suite of fibrous amphiboles for over 50 years. Dust mitigation measures have gradually reduced exposure, but continuous environmental follow-up is necessary in order to monitor exposure levels and prevent adverse health effects for future generations.

The quantitative scanning electron microscope-energy dispersive X-ray (SEM-EDX) analysis of a horneblende and two augite prismatic samples reduced to submicrometric particles was performed, and error due to the particle effects ("absent mass" and the "reduced absorption" effect) was minimized. Correction factors as a function of fragment size were obtained for O, Na, Mg, Si, Ca, and Fe. In addition, the influence of chemical composition of the samples used as standards (the matrix effect) on correction factors was evaluated. The results indicate that the absent mass effect is dominant for all elements except for the light elements O and Na, for which the reduced absorption effect is dominant. No significant matrix effect has been observed. By using corrected SEM-EDX data, the error on quantification of the element concentration has been estimated to be 3% relative for light elements and below 2% relative for heavy elements (notably, about 1% relative for Fe).

Background: It has been suggested that malignant mesothelioma might be mainly or only connected with the action of short and ultrathin fibres. On the basis of this hypothesis fibres less than 5 microm long and 0.2-0.1 microm thick would enter the pulmonary-pleura barrier and reach the parietal pleura thus inducing mesothelioma. The hypothesis raised a stimulating scientific discussion., Objectives: The aim of this communication is to report the initial results obtained comparing the size of amphibole fibres from healthy lung tissue with those from pleural tissue sampled from subjects whose death cause of death was mesothelioma., Methods: Four mesothelioma cases due to environmental exposure were studied; the fibres were categorized by scanning electron microscopy; for every fibre, length and diameter were measured and the mineral type was defined by its chemical composition determined by X-ray microanalysis., Results: The most important characteristics of the detected fibres were: the average length offibres from the lung and pleural tissues taken from the same subject did not difer, in all cases, by more than 10-12%; 95% offibres found in the lung tissues of all subjects had a length greater than 5 microm; 98% of fibres found in the pleural tissues had a length greater than 5 microm; the average diameter of the fibres found in the pleural tissues was 70% of the diameter of the fibres from the lung tissues., Conclusions: The experimental data obtained in this study confirm the correlation between malignant mesothelioma and the presence in the lung and pleural tissues of fibres with a length greater, even much greater, than 4-5 microm; thus the hypothesis that the chief factors inducing mesothelioma are the "ultrashort" and "ultrathin" fibres appears rather weak.

Malignant mesothelioma (MM) is an aggressive tumor associated with environmental or occupational exposure to asbestos fibers. Erionite is a fibrous zeolite, morphologically similar to asbestos and it is assumed to be even more carcinogenic. Onset and progression of MM has been suggested as the result of the cooperation between asbestos and other cofactors, such as SV40 virus infection. Nevertheless, several cases of MM were associated with environmental exposure to erionite in Turkey, where SV40 was never isolated in MM specimens. We show here that erionite is poorly cytotoxic, induces proliferating signals and high growth rate in human mesothelial cells (HMC). Long term exposure to erionite, but not to asbestos fibers, transforms HMC in vitro, regardless of the presence of SV40 sequences, leading to foci formation in cultured monolayers. Cells derived from foci display constitutive activation of Akt, NF-kappaB and Erk1/2, show prolonged survival and a deregulated cell cycle, involving cyclin D1 and E overexpression. Our results reveal that erionite is able per se to turn HMC into transformed highly proliferating cells and disclose the carcinogenic properties of erionite, prompting for a careful evaluation of environmental exposure to these fibers. The genetic predisposition to the effect of erionite is a separate subject for investigation.

An epidemiological and environmental study in the Biancavilla area (Sicily, Italy) was recently prompted by an impressively high incidence of malignant pleural mesothelioma. Epidemiology suggested an environmental contamination by amphibole fibres rather than risks related to a specific occupational activity. The aim of this study is to describe the diffusion of fibrous amphiboles in the area and identify their source. Fibrous amphiboles were found in the products from the local quarries, which had been used for years to build houses. After sampling all around Biancavilla, three sites were detected and they were characterized by an abundant presence of mineral fibres. Fibrous amphiboles were also recovered from building materials (mortar and plasters) and airborne particulates sampled in urban sites with high dust emissions due mainly to unpaved roads. Moreover, amphibole fibres were detected in the lung tissue of a woman who died of pleural mesothelioma. The results of this study suggest that the amphibole fibre diffusion in the Biancavilla environment lasted for many years and had been maximum during the sixties and the seventies with the uncontrolled development of the local building industry. Today, the environmental situation results to be changed following both the closing of the stone quarries and the urbanization works after 2001, above all the asphalting of dusty roads. Anyway sporadic mesothelioma cases have still to be expected in the next years.

An unusual cluster of malignant mesothelioma was evidenced in Biancavilla, a Sicily village where no inhabitant had been significantly and professionally exposed to asbestos. Mineralogical and environmental studies led to the identification of a new prismatic amphibole, named fluoro-edenite. We previously reported, by using the human lung epithelial A549 cells, that prismatic fluoro-edenite was unable to induce changes that could be somehow related to cellular transformation, and this was in accordance with studies carried out in vivo. More recently, a fibrous amphibole with a composition very similar to that of prismatic fluoro-edenite, was identified in Biancavilla. This fibrous fluoro-edenite was shown to induce mesothelioma in rats. In keeping with this effect in vivo, in the present work we observed multinucleation and spreading, common features of transformed cells, as well as pro-inflammatory cytokine release in A549 cells. Such cell changes occurred without interfering with the passage of the resulting multinucleated cells through the cell cycle and without condemning cells to death. Hence, in lung epithelial cells, fibrous fluoro-edenite behaved similarly to the unrelated asbestos type crocidolite, whose connection with severe inflammation and cancer of the lung is renowned.

Background: The necessity of quality control for laboratories carrying out airborne asbestos fibre monitoring is recognized in Italian law concerning the worker and the environmental protection against asbestos. The scanning electron microscopy technique is prescribed to control the airborne fibre concentration after asbestos removal from buildings., Objectives: In 2002 the Italian laboratories carrying out SEM analysis on asbestos were requested by the Istituto Superiore di Sanità to take part in a fibre count comparison program. Thirty-nine agreed to participate., Methods: Fifteen samples were exchanged among the laboratories participating in the program. Seven samples consisted of polycarbonate membranes and eight of cellulose ester membranes. The sample loads did not exceed 50 fibres/mm2. The fibre counting results were evaluated with reference to the mean value of each sample calculated from the results provided by all the participants., Results: Only 19% of the fibre count results were considered "insufficient", and the results falling within the 95% confidence interval were the 65% of the total. University and public laboratories obtained on the whole the best results.