Chrysotile Research Articles

Is the end near for chrysotile asbestos?

Despite intense lobbying by the chemical industry, the US Environmental Protection Agency is set to address the cancer risks posed by all current uses of chrysotile asbestos. In a final assessment ...

Is the end near for chrysotile asbestos?

Is the end near for chrysotile asbestos?

Колекція нерудної сировини музею рудних формацій Львівського національного університету імені Івана Франка

The article characterizes the collection of non-metallic raw materials, which is available in the expositions of the Museum of Ore Formations. Samples from deposits of sulphur, sodium and potassium salts, apatite, phosphorites, fluorite, chrysotile asbestos, graphite, mica, barium, strontium, piezooptical and ceramic raw materials are described.

Crystal structure determination of a lifelong biopersistent asbestos fibre using single-crystal synchrotron X-ray micro-diffraction.

The six natural silicates known as asbestos may induce fatal lung diseases via inhalation, with a latency period of decades. The five amphibole asbestos species are assumed to be biopersistent in the lungs, and for this reason they are considered much more toxic than serpentine asbestos (chrysotile). Here, we refined the atomic structure of an amosite amphibole asbestos fibre that had remained in a human lung for ∼40 years, in order to verify the stability in vivo. The subject was originally exposed to a blend of chrysotile, amosite and crocidolite, which remained in his parietal pleura for ∼40 years. We found a few relicts of chrysotile fibres that were amorphous and magnesium depleted. Amphibole fibres that were recovered were undamaged and suitable for synchrotron X-ray micro-diffraction experiments. Our crystal structure refinement from a recovered amosite fibre demonstrates that the original atomic distribution in the crystal is intact and, consequently, that the atomic structure of amphibole asbestos fibres remains stable in the lungs for a lifetime; during which time they can cause chronic inflammation and other adverse effects that are responsible for carcinogenesis. The amosite fibres are not iron depleted proving that the iron pool for the formation of the asbestos bodies is biological (haemoglobin/plasma derived) and that it does not come from the asbestos fibres themselves.

Молекулярные аспекты канцерогенеза, индуцированного асбестом

One of the key problems of modern healthcare is the prevention and personalized medicine of diseases caused by exposure to adverse environmental factors. According to the World Health Organization and the International Agency for Research on Cancer, all forms of asbestos have adverse effects on the human body and can induce various forms of cancer. It has been evidenced by the inclusion of asbestos in the first category of the list of carcinogens. Today the Republic of Kazakhstan is one of the largest asbestos-producing countries. An understanding of the key mechanisms of carcinogenesis due to inhalation of asbestos is needed to effectively diagnose asbestos-induced cancer in the early stages of development. The article reports on the most modern concepts of the genetic and molecular mechanisms of carcinogenesis mediated by the effect of chrysotile asbestos and confirms the danger of this compound to human health.

Portable Raman Spectrometer for In Situ Analysis of Asbestos and Fibrous Minerals

Asbestos inhalation is associated with fatal respiratory diseases and raises concerns from the perspective of workplace safety and environmental impacts. Asbestos and asbestos-like minerals naturally occur in rocks and may become airborne when outcrops or soils are disturbed by anthropic activities. In situ detection of these minerals is a crucial step for the risk evaluation of natural sites. We assess here whether a portable Raman spectrometer (pRS) may be used in the identification of asbestos and asbestos-like minerals at the mining front during exploitation. pRS performance was tested at three geologically different mining sites in Italy and New Caledonia and compared with a high-resolution micro-Raman spectrometer (HRS). About 80% of the overall in situ analyses at the mining front were successfully identified by pRS, even when intermixed phases or strongly disaggregated and altered samples were analyzed. Chrysotile and tremolite asbestos, asbestos-like antigorite, and balangeroite were correctly detected during surveys. The major difficulties faced during in situ pRS measurements were fluorescence emission and focussing the laser beam on non-cohesive bundles of fibers. pRS is adequate for discriminating asbestos and asbestos-like minerals in situ. pRS may support risk assessment of mining sites to better protect workers and environment.

Association of genetic polymorphism of cytokines and antioxidant enzymes with the development of asbestosis

Introduction. Various industries widely use chrysotile asbestos, which determines the relevance of research aimed at the prevention of asbestos-related diseases. It is promising to assess the role of specific genes, which products are potentially involved in the development and regulation of certain links in the pathogenesis of asbestosis, forming a genetic predisposition to the disease. The study aims to analyze the presence of associations of genetic polymorphism of cytokines and antioxidant enzymes with asbestosis development. Materials and methods. Groups were formed for examination among employees of OJSC "Uralasbest" with an established diagnosis of asbestosis and without lung diseases. For each person included in the study, dust exposure doses were calculated considering the percentage of time spent at the workplace during the shift for the entire work time. Genotyping of single nucleotide polymorphisms of cytokines IL1b (rs16944), IL4 (rs2243250), IL6 (rs1800795), TNFα (rs1800629) and antioxidant enzymes SOD2 (rs4880), GSTP1 (rs1610011), CAT (rs1001179) was carried out. Results. The authors revealed the associations of polymorphic variants A511G IL1b gene (OR=2.457, 95% CI=1.232-4.899) and C47T SOD2 gene (OR=1.705, 95% CI=1.055-2.756) with the development of asbestosis. There was an increase in the T allele IL4 gene (C589T) frequency in persons with asbestosis at lower values of dust exposure doses (OR=2.185, 95% CI=1.057-4.514). The study showed the associations of polymorphism C589T IL4 gene and C174G IL6 gene with more severe asbestosis, polymorphism A313G GSTP1 gene with pleural lesions in asbestosis. Conclusion. Polymorphic variants of the genes of cytokines and antioxidant enzymes, the protein products directly involved in the pathogenetic mechanisms of the formation of asbestosis, contribute to forming a genetic predisposition to the development and severe course of asbestosis. Using the identified genetic markers to identify risk groups for the development and intense period of asbestos-related pathology will optimize treatment and preventive measures, considering the organism's characteristics.

Characterization and assessment of the potential toxicity/pathogenicity of Russian commercial chrysotile

AbstractToday, cancer is one of the main health issues faced in the workplace, with asbestos an important carcinogen in the occupational environment. Among the asbestos minerals, chrysotile is the main species of socio-economic and industrial relevance. Although chrysotile asbestos is classified as a “carcinogenic substance” by the International Agency for Research on Cancer (IARC), this fiber is still mined and used in Russia. The effective health hazard posed by the Russian commercial chrysotile has not been quantitatively assessed to date. In this work, the potential toxicity/pathogenicity of Russian chrysotile was quantitatively determined using the fiber potential toxicity index (FPTI) model. This model was applied to a representative commercial chrysotile from the Orenburg region, Russia, whose morphometric, crystal-chemical, surface activity, and biodurability related parameters were determined. We have quantitatively assessed that the toxicity/pathogenicity potential of Russian chrysotile (FPTI = 2.4) is lower than that of amphibole asbestos species but higher than the threshold limit set for “safe” mineral fibers (FPTI = 2.0), although it does not contain impurities of amphibole asbestos. Differences with other chrysotile samples were discussed, and it was found that the investigated Russian commercial chrysotile shares several features with the Italian Balangero chrysotile, indicating that widespread concern on commercial Russian chrysotile is justified.

Fortification of building’s foundations with eco-friendly materials as means to safer and more comfortable urban environment

In this paper we tested mechanical aspects of chemical reactions as means to fortification of clay soil. We also tested properties of soil-concrete using waste of dolomite and chrysotile asbestos. The composition and properties of the composites are presented along with the comparison with traditional reinforced cementing materials. Main testing means of properties were method of x-ray phase analysis, electric scanning microscopy, soil strength changes and soil internal friction angle changes.

Selection of a Method for Protecting the Environment from Contamination during the Asbestos Containing Ore Mining

Analysis of the mechanism of quarry waters contamination during drilling and blasting preparation of asbestos containing raw materials under the influence of industrial and natural factors is carried out that can serve as a basis for making specific technological decisions ensuring a decrease in the negative impact on the environment during the development of chrysotile asbestos deposits. The dependence of the nitrogen compounds inflow in quarry waters on the consumption of explosives and the volume of quarry waters formation is presented. The possibility of quarry water treatment in the depleted open-pit minings, the sides of which are composed of plastic asbestos containing rocks, is shown. The relationship between the volumes of internal dumping and the contamination of quarry drainage waters has been analyzed.

Asbestos exposure risk from ceiling and other building materials

Although much research has been conducted regarding asbestos removal and worker exposure, there are gaps in our understanding of the extent of asbestos-containing materials still present in building materials and the effectiveness of exposure controls used during the removal of these materials. We conducted a review of third party surveys and exposure assessment reports to: (1) Evaluate the exposure levels measured by personal and area asbestos air sampling during abatement of ceiling and other building materials to measure the effectiveness of site controls, (2) summarize the type and concentration of asbestos identified in residential and commercial buildings’ building materials. A literature research was performed using Bing, Google, and Yahoo search engines to identify (commercially) unpublished asbestos survey reports and air sampling reports during asbestos removal to assess exposure potentials. The data extracted resulted in 3012 bulk samples assessed for concentration and type; 617 contained asbestos. Forty-one types of Asbestos-containing material (ACM) were identified. All ACMs identified were chrysotile. The chrysotile concentration in the bulk samples ranged from non-detectable to 100%. Air sampling exposure data from two asbestos abatement projects were assessed. The maximum unweighted (time) personal exposure measured was 0.0201 f/cc. Based on our evaluation of the exposure records from the removal of ACM in both commercial and residential settings where type and concentration of asbestos was known, the risk for overexposure is low based on the effectiveness of implemented risk management strategies. Key words: Asbestos, abatement, occupational exposure , environmental monitoring.

Mesothelioma risk among those exposed to chrysotile asbestos only and mixtures that include amphibole: a case–control study in the USA, 1975–1980

ObjectivesOccupational asbestos exposure is causally linked to mesothelioma. However, whether exposure to only chrysotile asbestos is associated with mesothelioma risk, and the heterogeneity in risk by different fibre types/lengths remains...

Mechanochemical conversion of chrysotile asbestos tailing into struvite for full elements utilization as citric-acid soluble fertilizer

Chrysotile asbestos tailing (CAT) are rich in magnesium and silicon which are of great value for crop growth. In this work, CAT was transformed to struvite and silicate salt for the first time by one-step milling with phosphates (NH4H2PO4, (NH4)2HPO4, KH2PO4 and CaHPO4) for full elements utilization as citric acid soluble fertilizer (CASF). The X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TG) and Scanning electron microscopy (SEM) were used to characterize the obtained samples. The nutrients release data revealed that CAT milling with (NH4)2HPO4 and CaHPO4 was optimal for the production of Mg, N, P, and Si compound CASF which released 0% Mg, 9.37% N, 2.02% P, and 9.86% Si in water and 94.54% Mg, 96.79% N, 96.97% P, and 14.02% Si in 2% citric acid. The prepared product held the nutrients by the mechanism of struvite crystallization in water and released the nutrients by acid-dissolution in citric acid solution. Techno-economic analysis proved the feasibility and economic value of the CASF produced by the proposed mechanochemical approach. This facile and environmentally friendly process would surely contribute to the improvement of resource utilization efficiency and create a sustainable and environmental friendly agricultural production system.

AUTOIMMUNE MARKERS FOR PROGRESSION OF LIBBY AMPHIBOLE LAMELLAR PLEURAL THICKENING

SESSION TITLE: Occupational and Environmental Lung Disease SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: The Libby Epidemiological Research Program, funded by the Agency for Toxic Substances and Disease Registry, found that autoimmune outcomes were associated with exposure to Libby Asbestiform Amphibole (LAA). THis has been previously published. In addition to the cancers and pulmonary fibrosis typically found with chrysotile asbestos, a highly inflammatory and progressive pleural fibrosis (LPT – lamellar pleural thickening) is frequently found in people exposed to LAA. Progressive LPT can lead to severe pleural pain and/or rapidly worsening pulmonary function. Autoantibodies have been shown to occur in mice and humans exposed to LAA. The purpose of this study was to determine which specific autoantibodies, if any, were related to progressive LPT and to perform sensitivity and specificity testing to determine their usefulness as potential screening markers for progressive disease. METHODS: After IRB approval, a selection of adult patients from the Center for Asbestos Related Diseases (CARD) database was stratified into groups as Progressive LPT, Stable LPT, and no LPT. Participants were required to have had a CT scan of the chest without contrast within the past 2 years as well as a serum sample drawn within 2 years of their CT scan. Two patients each were selected from the Stable LPT and No LPT groups and matched as close as possible to the 19 participants in the Progressive LPT group. Samples were analyzed for ANA (anti-nuclear antibody), MCAA (mesothelial cell autoantibodies), (PLG) Antiplasminogen, Cytokines IL-1beta and IL-17. Afterwards, statistical analysis was applied to determine sensitivity and specificity. RESULTS: ANA was found more frequently in the Progressor group than the Stable or No groups. Positive MCAA was more frequent in the Progressor group, but only statistically greater than the No group. Positive PLG was more frequent in the Progressor group than both the Stable and No groups. IL-1beta and IL-17 had no significant differences between groups. All three antibodies, ANA, MCAA, and PLG, had higher specificity than sensitivity. The most specific test with the strongest predictive values was PLG. When the Stable group was included, none of the three tests had predictive value as a screening test. CONCLUSIONS: Screening for autoimmune markers associated with Progressive PLT might allow early detection and also suggest new therapeutic strategies. The data cited in this study support the association of ANA, MCAA, and PLG with progressive LPT but not stable LPT. CLINICAL IMPLICATIONS: ANA may have some role as a screening tool for risk of severe clinical disease with LPT progression. PLG or MCAA may have some role in predicting progressive LPT, especially when combined with ANA, but while there may be high specificity, sensitivity remains low. Further studies need to validate this finding in women. None of these markers had value in predicting Stable PT. DISCLOSURES: no disclosure on file for Charles Black; No relevant relationships by Tracy McNew, source=Web Response No relevant relationships by Karen Lee Morrissette, source=Web Response No relevant relationships by Jean Pfau, source=Web Response

A Quantitative Retrospective Exposure Assessment for Former Chrysotile Asbestos Miners and Millers from Baie Verte, NL, Canada.

Despite numerous studies of asbestos workers in the epidemiologic literature, there are very few cohort studies of chrysotile asbestos miners/millers that include high-quality retrospective exposure assessments. As part of the creation of the Baie Verte Miners' Registry in 2008, a two-dimensional job exposure matrix (JEM) was developed for estimating asbestos exposures for former chrysotile asbestos miners/millers. Industrial hygiene data collected between 1963 and 1994 were analysed to assess validity for use in a retrospective exposure assessment and epidemiologic study. Registered former employees were divided into 52 exposure groups (EGs) based on job title and department and mean asbestos concentrations were calculated for each EG. The resulting exposure estimates were linked to individual registrants' work histories allowing for the calculation of cumulative asbestos exposure for each registrant. The distribution of exposure for most EGs (82.6%) could be described as fitting a log-normal distribution, although variability within some EGs (55%) exceeded a geometric standard deviation (GSD) of 2.5. Overall, the data used to create EGs in the development of the JEM were deemed to be of adequate quality for estimating cumulative asbestos exposures for the former employees of the Baie Verte asbestos mine/mill. The variability between workers in the same job was often high and is an important factor to be considered when using estimates of cumulative asbestos exposure to adjudicate compensation claims. The exposures experienced in this cohort were comparable to those of other chrysotile asbestos miners/millers cohorts, specifically Italian and Québec cohorts.

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

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.

Chrysotile asbestos ― raw materials of the construction industry from deep quarries

A ladle belt conveyor with increased traction ability is proposed at the request of Kostanay Minerals JSC. A geometric diagram of the conveyor route for cyclic-flow technology with the transportation of rock mass steeply falling conveyors in the contours of the quarry of the first stage of the Dzhetygara chrysotile deposit is given. The calculation of the geometric dimensions of individual sections of the conveyor is performed. The parameters of the transported material, the route and the bucket belt conveyor itself are determined.

Immunological Risk Factors for Community-Acquired Pneumonia in Chrysotile Asbestos Workers

Introduction: The paper presents the results of a retrospective analysis of the incidence rates of community-acquired pneumonia in chrysotile miners and millers in comparison with the adult population of a municipality. It also demonstrates findings of the study of some immune response parameters in Streptococcus pneumoniae carriers among chrysotile asbestos workers. The objective of the research was to study specifics of the development of community-acquired pneumonia and to determine immune indices in healthy workers (Streptococcus pneumoniae carriers) occupationally exposed to chrysotile asbestos. Materials and methods: First, we analyzed community-acquired pneumonia incidence rates in chrysotile asbestos workers. For the retrospective analysis, we extracted comprehensive emergency notifications about cases of infectious disease, food poisoning, acute occupational poisoning, community-acquired pneumonia, and vaccine adverse reactions (Form 058/u) from the Epidemiologic Surveillance Information System maintained by the Sverdlovsk Regional Center for Hygiene and Epidemiology and Federal Statistics Form No. 2 “Information about Infectious and Parasitic Diseases” in the Sverdlovsk Region. We defined jobs and formed three groups of workers with high incidence rates of community-acquired pneumonia: group 1 included workers involved in extraction and transportation of chrysotile asbestos, group 2 consisted of workers of the ore-dressing factory while group 3 included workers of auxiliary subdivisions (logistics, security, administration, central automated control station). In 2011, 2012, 2013, and 2019, the incidence rate of community-acquired pneumonia in workers was significantly higher. The annual increase had been observed since 2016 and reached its maximum of 1,032.97±158.88 in 2019 exceeding the long-term average rate in the industry and the town by 12.77 % and 15 %, respectively. We assessed the immune status and performed a comparative analysis of immunological indices in 143 workers of selected jobs, both carriers and noncarriers of Streptococcus pneumoniae. The carriers demonstrated a significant increase in the production immunoglobulin E indicating general sensitization and immunoglobulin G, a significantly lower relative count of mature T cells, and a higher lymphocyte count in the populations of natural killer cells.

Chrysotile Asbestos: Raw Materials for the Construction Industry from Deep Quarries

A bucket belt conveyor with increased traction ability is proposed at the request of Kostanay Minerals JSC. A geometric diagram of the conveyor circuit for the cyclical-flow technology with the transportation of rock mass by steeply inclined conveyors in the contours of the quarry of the first stage of the Dzhetygara chrysotile deposit is given. The calculation of the geometric dimensions of individual sections of the conveyor is performed. The parameters of the transported material, the circuit and the bucket belt conveyor itself have are determined.

Asbestos-Based Pottery from Corsica: The First Fiber-Reinforced Ceramic Matrix Composite.

Asbestos-containing pottery shards collected in the northeast of Corsica (Cap Corse) and dating from the 19th century, or earlier, have been analyzed by SEM-EDS, XRPD, FTIR and Raman microspectroscopy. Blue (crocidolite) and white (chrysotile) asbestos fiber bundles are observed in cross-sections. Most of the asbestos is partly or totally dehydroxylated, and some transformation to forsterite is observed to occur, indicative of a firing above 800 °C. Examination of freshly fractured pieces shows a nonbrittle fracture with fiber pull-out, consistent with a composite material behavior, which makes these ceramics the oldest fiber-reinforced ceramic matrix composite. Residues indicate the use of this pottery as a crucible for gold extraction using cyanide.