Asbestos: Mineralogical features and fiber analysis in biological materials.

Asbestos is a mineral with unique physical and chemical properties that make it highly resistant to heat, fire, and corrosion. Nevertheless, exposure to asbestos fibers has been linked to serious health problems, including lung cancer, mesothelioma, and asbestosis. Despite the ban on asbestos usage, asbestos-related diseases are still a major cause of morbidity and mortality worldwide. Analyzing the mineralogical features and fiber analysis of asbestos in biological materials is critical for scenarios where an asbestos exposure history cannot be obtained, a clinical diagnosis cannot be made, or legal aspects necessitate further investigation. This review outlines the mineralogical features and fiber analysis techniques of asbestos in biological materials.

Pneumoconiosis combined with connective tissue disease in China: a cross-sectional study.

OBJECTIVE: To describe the prevalence, clinical features and potential risk factors of pneumoconiosis in combination with connective tissue disease (CTD) or positive autoantibodies. DESIGN: Cross-sectional study. SETTING: A retrospective study of adults recruited in China between December 2016 and November 2021. PARTICIPANTS: A total of 931 patients with pneumoconiosis at Beijing Chao-Yang Hospital were enrolled in this study; of these, 580 patients were included in the final analysis. MAIN OUTCOME MEASURES: Pneumoconiosis combined with CTD or positive autoantibodies was a major adverse outcome. RESULTS: In total, 13.8% (80/580) of the patients had combined pneumoconiosis with CTD, among whom the prevalence of CTD was 18.3% (46/251) in asbestosis and 11.4% (34/298) in silicosis/coal mine workers' pneumoconiosis. In comparison to the general Chinese adult population, the relative risk of various CTD in pneumoconiosis, including rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, primary Sjögren's syndrome, idiopathic inflammatory myopathy and antineutrophil cytoplasmic antibodies-associated vasculitis, were 11.85, 12.12, 127.40, 4.23, 9.94 and 644.66, respectively. Multivariate analysis revealed that female sex (OR 2.55, 95% CI 1.56 to 4.17) and a later stage of pneumoconiosis (OR 2.04, 95% CI 1.24 to 3.34) were the independent risk factors for CTD in patients with pneumoconiosis (all p<0.050). CONCLUSION: CTD is highly prevalent in patients with pneumoconiosis, especially in patients of asbestosis, and silicosis/coal mine workers' pneumoconiosis. Female sex and later stages of pneumoconiosis are associated with an increased risk of combined with CTD.

Closing the knowledge gap on the composition of the asbestos bodies.

Asbestos bodies (AB) form in the lungs as a result of a biomineralization process initiated by the alveolar macrophages in the attempt to remove asbestos. During this process, organic and inorganic material deposit on the foreign fibers forming a Fe-rich coating. The AB start to form in months, thus quickly becoming the actual interface between asbestos and the lung tissue. Therefore, revealing their composition, and, in particular, the chemical form of Fe, which is the major component of the AB, is essential to assess their possible role in the pathogenesis of asbestos-related diseases. In this work we report the result of the first x-ray diffraction measurements performed on single AB embedded in the lung tissue samples of former asbestos plant workers. The combination with x-ray absorption spectroscopy data allowed to unambiguously reveal that Fe is present in the AB in the form of two Fe-oxy(hydroxides): ferrihydrite and goethite. The presence of goethite, which can be explained in terms of the transformation of ferrihydrite (a metastable phase) due to the acidic conditions induced by the alveolar macrophages in their attempt to phagocytose the fibers, has toxicological implications that are discussed in the paper.

Chronological trends in the causation of malignant mesothelioma: Fiber burden analysis of 619 cases over four decades.

Malignant mesothelioma is a relatively rare malignancy with a strong association with prior asbestos exposure. A percentage of cases is not related to asbestos, and fiber analysis of lung tissue is a useful methodology for identifying idiopathic or spontaneous cases. We have performed fiber analyses in more than 600 cases of mesothelioma over the past four decades and were interested in looking for trends in terms of fiber types and concentrations as well as percentages of cases not related to asbestos. Demographic information was also considered including patient age, gender, and tumor location (pleural vs. peritoneal). The histologic pattern of the tumor and the presence or absence of pleural plaques or asbestosis were noted. Fiber analysis was performed in 619 cases, using the sodium hypochlorite technique for digestion of lung tissue samples. Asbestos bodies were counted by light microscopy (LM) and coated and uncoated fibers by scanning electron microscopy (EM). The results were stratified over four decades. Trends that were observed included increasing patient age, increasing percentage of women, increasing percentage of peritoneal cases, and increasing percentage of epithelial histological type. There was a decreasing trend in the percentage of patients with concomitant asbestosis (p < 0.001). The percentage of cases with an elevated lung asbestos content decreased from 90.5% in the 1980s to 54.1% in the 2010s (p < 0.001). This trend also held when the analysis was limited to 490 cases of pleural mesothelioma in men (91.8% in the 1980s vs. 65.1% in the 2010s). There was a decrease in the median asbestos body count by LM from 1390 asbestos bodies per gram of wet lung in the 1980s to 38 AB/gm in the 2010s. Similar trends were observed for each of the asbestos fiber types as detected by EM. We conclude that there has been a progressive decrease in lung fiber content of mesothelioma patients during the past four decades, with an increasing percentage of cases not related to asbestos and an increase in median patient age.

Mortality rates from asbestos-related diseases in Italy during the first year of the COVID-19 pandemic.

Background and aim: Patients with interstitial lung diseases, including asbestosis, showed high susceptibility to the SARS-CoV-2 virus and a high risk of severe COVID-19 symptoms. Italy, highly impacted by asbestos-related diseases, in 2020 was among the European countries with the highest number of COVID-19 cases. The mortality related to malignant mesotheliomas and asbestosis in 2020 and its relationship with COVID-19 in Italy are investigated. Methods: All death certificates involving malignant mesotheliomas or asbestosis in 2010-2020 and those involving COVID-19 in 2020 were retrieved from the National Registry of Causes of Death. Annual mortality rates and rate ratios (RRs) of 2020 and 2010-2014 compared to 2015-2019 were calculated. The association between malignant pleural mesothelioma (MPM) and asbestosis with COVID-19 in deceased adults ≥80 years old was evaluated through a logistic regression analysis (odds ratios: ORs), using MPM and asbestosis deaths COVID-19-free as the reference group. The hospitalization for asbestosis in 2010-2020, based on National Hospital Discharge Database, was analyzed. Results: In 2020, 746,343 people died; out of them, 1,348 involved MPM and 286 involved asbestosis. Compared to the period 2015-2019, the mortality involving the two diseases decreased in age groups below 80 years; meanwhile, an increasing trend was observed in subjects aged 80 years and older, with a relative mortality risks of 1.10 for MPM and 1.17 for asbestosis. In subjects aged ≥80 years, deaths with COVID-19 were less likely to have MPM in both genders (men: OR = 0.22; women: OR = 0.44), while no departure was observed for asbestosis. A decrease in hospitalization in 2020 with respect to those in 2010-2019 in all age groups, both considering asbestosis as the primary or secondary diagnosis, was observed. Conclusions: The increasing mortality involving asbestosis and, even if of slight entity, MPM, observed in people aged over 80 years during the 1st year of the COVID-19 pandemic, aligned in part with the previous temporal trend, could be due to several factors. Although no positive association with COVID-19 mortality was observed, the decrease in hospitalizations for asbestosis among individuals aged over 80 years, coupled with the increase in deaths, highlights the importance of enhancing home-based assistance during the pandemic periods for vulnerable patients with asbestos-related conditions.

Case-fatality study of workers and residents with radiographic asbestos disease in Libby, Montana.

BACKGROUND: Vermiculite ore from Libby, Montana contains on average 24% of a mixture of toxic and carcinogenic amphibole asbestiform fibers. These comprise primarily winchite (84%), with smaller quantities of richterite (11%) and tremolite (6%), which are together referred to as Libby amphibole (LA). METHODS: A total of 1883 individuals who were occupationally and/or environmentally exposed to LA and were diagnosed with asbestos-related pleuropulmonary disease (ARPPD) following participation in communitywide screening programs supported by the Agency for Toxic Substances and Disease Registry (ATSDR) and followed up at the Center for Asbestos Related Disease (CARD) between 2000 and 2010. There were 203 deaths of patients with sufficient records and radiographs. Best clinical and radiologic evidence was used to determine the cause of death, which was compared with death certificates. RESULTS: Asbestos-related mortality was 55% (n = 112) in this series of 203 patients. Of the 203 deaths, 34 (17%) were from asbestos-related malignancy, 75 (37%) were from parenchymal asbestosis, often with pleural fibrosis, and 3 (1.5%) were from respiratory failure secondary to pleural thickening. CONCLUSIONS: Asbestos is the leading cause of mortality following both occupational and nonoccupational exposure to LA in those with asbestos-related disease.

Environmental asbestos exposure and nonmalignant pleural findings: a retrospective evaluation of a five-year chest CT repository.

This registry-based case-control study aimed to assess the association between asbestos deposits in the birthplace and/or residence and nonmalignant pleural findings, namely pleural plaques (PPs) and pleural thickening (PT), on chest CT scans. In total, 39,472 CT scans obtained over five years in a tertiary referral hospital in Ankara, Turkey, were evaluated. Cases involving patients with PP (n = 537), PT (n = 263), PP&PT (n = 69), and controls (n = 543) from the same study base without those conditions were included. Each case group was compared to controls using unconditional logistic regression. The presence of asbestos deposits in the district of birthplace (adjusted OR = 2.13, 95% CI: 1.35-3.37) and both birthplace and residence (aOR = 4.32, 95% CI: 2.26-8.27) was significantly related to the PPs. As the importance of environmental asbestos exposure in Turkey continues, future prospective studies could contribute to developing screening strategies.

Asbestosis hospitalizations in Poland (2006-2016): results from the National Hospital Discharge Registry.

INTRODUCTION AND OBJECTIVE: Occupational asbestos exposure is one of the major public health issues. Although asbestos use in Poland has decreased, asbestosis continues to remain an important health concern in the area of occupational medicine. The aim of the study is to perform a descriptive analysis of hospitalization cases in patients suffering from asbestosis in Poland. MATERIAL AND METHODS: The authors used hospital discharge records to conduct a retrospective, population-based study. To estimate the asbestosis hospitalization rate, data from the Nationwide General Hospital Morbidity Study conducted by the National Institute of Public Health were used. Events were defined as in-patient hospital discharges during 2006-2016. 1,101 hospitalization records of 764 patients were included in the study. RESULTS: In the study group of first-time hospitalized patients, the mean and median ages were 68.1 and 69 years, respectively; CI: 67.3-68.9; SD: 11.1, min-max:16-99 years. In this group, significant gender differences were observed (560 males vs. 204 female; P<0.001). No statistical differences were observed regarding the place of residence. During the observation period, 61 in-hospital deaths were reported (8% of all patients), 40 of whom (5.2 % of all patients) took place during the first-time hospitalizations. Asbestosis hospitalizations were mainly clustered in the south-western region, whereas the highest hospitalization rates were clustered in several areas of Poland. CONCLUSIONS: The authors believe this study to be the first evaluation of asbestosis in Poland made on the basis of the hospital morbidity database. The data presented may be helpful in comparative studies on the epidemiology of asbestosis across European countries.

Psychological Distress after a Diagnosis of Malignant Mesothelioma in a Group of Patients and Caregivers at the National Priority Contaminated Site of Casale Monferrato.

BACKGROUND: Patients of malignant mesothelioma (MM) and their caregivers face significant physical and psychological challenges. The purpose of the present study is to examine the emotional impact after the diagnosis of MM in a group of patients and familial caregivers in a National Priority Contaminated Site (NPCS). METHODS: A sample of 108 patients and 94 caregivers received a sociodemographic/clinical questionnaire, the Beck Depression Inventory II, the Davidson Trauma Scale, the Coping Orientation to the Problems Experienced-New Italian Version, and the Defense style questionnaire. The risk of depressive and post-traumatic stress disorder (PTSD) symptoms in relation to the strategies of coping and defense mechanisms was estimated in patients and caregivers separately by logistic regression models. RESULTS: For patients, a high risk of depression was associated with high usage of Defense Style Questionnaire (DSQ) Isolation (OR: 53.33; 95% CI: 3.22-882.30; p = 0.01) and DSQ Somatization (OR: 16.97; 95% CI: 1.04-275.90; p = 0.05). Other significant risks emerged for some coping strategies and some defenses regarding both depression and trauma in patients and caregivers. CONCLUSIONS: This research suggests that for both patients and caregivers unconscious adaptive processes have a central role in dealing with overwhelming feelings related to the disease.

Mitochondrial 8-oxoguanine DNA glycosylase mitigates alveolar epithelial cell PINK1 deficiency, mitochondrial DNA damage, apoptosis, and lung fibrosis.

Alveolar epithelial cell (AEC) apoptosis, arising from mitochondrial dysfunction and mitophagy defects, is important in mediating idiopathic pulmonary fibrosis (IPF). Our group established a role for the mitochondrial (mt) DNA base excision repair enzyme, 8-oxoguanine-DNA glycosylase 1 (mtOGG1), in preventing oxidant-induced AEC mtDNA damage and apoptosis and showed that OGG1-deficient mice have increased lung fibrosis. Herein, we determined whether mice overexpressing the mtOGG1 transgene (mtOgg1tg) are protected against lung fibrosis and whether AEC mtOGG1 preservation of mtDNA integrity mitigates phosphatase and tensin homolog-induced putative kinase 1 (PINK1) deficiency and apoptosis. Compared with wild type (WT), mtOgg1tg mice have diminished asbestos- and bleomycin-induced pulmonary fibrosis that was accompanied by reduced lung and AEC mtDNA damage and apoptosis. Asbestos and H2O2 promote the MLE-12 cell PINK1 deficiency, as assessed by reductions in the expression of PINK1 mRNA and mitochondrial protein expression. Compared with WT, Pink1-knockout (Pink1-KO) mice are more susceptible to asbestos-induced lung fibrosis and have increased lung and alveolar type II (AT2) cell mtDNA damage and apoptosis. AT2 cells from Pink1-KO mice and PINK1-silenced (siRNA) MLE-12 cells have increased mtDNA damage that is augmented by oxidative stress. Interestingly, mtOGG1 overexpression attenuates oxidant-induced MLE-12 cell mtDNA damage and apoptosis despite PINK1 silencing. mtDNA damage is increased in the lungs of patients with IPF as compared with controls. Collectively, these findings suggest that mtOGG1 maintenance of AEC mtDNA is crucial for preventing PINK1 deficiency that promotes apoptosis and lung fibrosis. Given the key role of AEC apoptosis in pulmonary fibrosis, strategies aimed at preserving AT2 cell mtDNA integrity may be an innovative target.

[Effects of Asbestos on Human Health. Document of the Italian Epidemiological Association (AIE)]. / Effetti dell'amianto sulla salute. Documento dell'Associazione Italiana di Epiemiologia (AIE).

OBJECTIVES: the Italian Epidemiological Association (AIE) intends to formulate assessments and recommendations on the most relevant and critical aspects in the preparation, conduct, and interpretation of epidemiological investigations on the health effects of exposure to asbestos and asbestos-like fibres. DESIGN, SETTING, AND PARTICIPANTS: the document was prepared by a working group of AIE associates, with a broad curriculum of epidemiological investigations, starting from the evaluation of scientific evidence, and was subsequently evaluated by the AIE governing body. RESULTS: the topics covered included: • consumption and presence of asbestos; • association between asbestos exposure and disease; • epidemiological surveillance of asbestos related diseases in Italy; • risk function for asbestos related diseases; • increased risk and anticipation of the disease; • interaction between asbestos and other carcinogens; • diagnosis in epidemiological studies; • assessment of exposure to asbestos; • epidemiological evidence on asbestos related diseases. CONCLUSIONS: the document ends with a summary of the conclusions of scientific research shared by AIE, with reflection on the methodology to be followed for the application at individual level of the results of epidemiological studies, and the proposal of themes on which to direct research.

Are the knowledge of non-malignant asbestos-related diseases and lung function impairment differentially associated with psychological well-being? A cross-sectional study in formerly asbestos-exposed workers in Germany.

OBJECTIVES: The knowledge of past asbestos exposure may lead to chronic psychological strain. In addition, the information about an increased cancer risk can place a psychological burden on individuals triggering mental health symptoms of depression or anxiety. This applies in particular to individuals with non-malignant asbestos-related disease (ARD) such as lung fibrosis and pleural thickening with or without lung function impairment. ARDs with or without lung function impairment may develop even years after exposure cessation. Therefore, the aim of the present study was to test for our cohort whether non-malignant ARD and lung function impairment have differential effects on mental health and psychological strain. DESIGN: Cross-sectional study. PARTICIPANTS AND SETTING: Overall, 612 male participants (mean age=66.2 years, SD=9.5) attending a surveillance programme for ARDs received routine examinations including lung function testing (24% refused to fill in the psychological questionnaire) at a German university hospital study centre from August 2008 to August 2013. OUTCOME MEASURES: Using multiple hierarchical regression analysis, ARD diagnosis and lung function impairment were used to predict psychological health as measured with validated questionnaires for depression and anxiety. Psychological strain was operationalised by intrusive thoughts and specific fear of cancer. RESULTS: The strongest predictor for mental health was obstructive functional impairment (eg, anxiety: ß=0.22, p<0.001). Psychological strain was predicted by the presence of a non-malignant ARD (eg, intrusive thoughts: ß=0.17, p=0.003). CONCLUSIONS: The presence of mental health symptoms is associated with ventilation disturbances, whereas the knowledge of an already initiated morphological change-caused by asbestos exposure-is primarily associated with psychological strain. Specifically, the affected individuals are more prone to intrusive thoughts and specific fear of asbestos-related cancer. As an implication, physicians should be sensitised about possible consequences of risk communication and functional impairment to counteract excessive fear or anxiety.

Cumulative asbestos exposure and mortality from asbestos related diseases in a pooled analysis of 21 asbestos cement cohorts in Italy.

BACKGROUND: Despite the available information on cancer risk, asbestos is used in large areas in the world, mostly in the production of asbestos cement. Moreover, questions are raised regarding the shape of the dose response relation, the relation with time since exposure and the association with neoplasms in various organs. We conducted a study on the relationship between cumulative asbestos exposure and mortality from asbestos related diseases in a large Italian pool of 21 cohorts of asbestos-cement workers with protracted exposure to both chrysotile and amphibole asbestos. METHODS: The cohort included 13,076 workers, 81.9% men and 18.1% women, working in 21 Italian asbestos-cement factories, with over 40 years of observation. Exposure was estimated by plant and period, and weighted for the type of asbestos used. Data were analysed with consideration of cause of death, cumulative exposure and time since first exposure (TSFE), and by gender. SMRs were computed using reference rates by region, gender and calendar time. Poisson regression models including cubic splines were used to analyse the effect of cumulative exposure to asbestos and TSFE on mortality for asbestos-related diseases. 95% Confidence Intervals (CI) were computed according to the Poisson distribution. RESULTS: Mortality was significantly increased for 'All Causes' and 'All Malignant Neoplasm (MN)', in both genders. Considering asbestos related diseases (ARDs), statistically significant excesses were observed for MN of peritoneum (SMR: men 14.19; women 15.14), pleura (SMR: 22.35 and 48.10), lung (SMR: 1.67 and 1.67), ovary (in the highest exposure class SMR 2.45), and asbestosis (SMR: 507 and 1023). Mortality for ARDs, in particular pleural and peritoneal malignancies, lung cancer, ovarian cancer and asbestosis increased monotonically with cumulative exposure. Pleural MN mortality increased progressively in the first 40 years of TSFE, then reached a plateau, while peritoneal MN showed a continuous increase. The trend of lung cancer SMRs also showed a flattening after 40 years of TSFE. Attributable proportions for pleural, peritoneal, and lung MN were respectively 96, 93 and 40%. CONCLUSIONS: Mortality for ARDs was associated with cumulative exposure to asbestos. Risk of death from pleural MN did not increase indefinitely with TSFE but eventually reached a plateau, consistently with reports from other recent studies.

High frequency and severity of pleural changes in former workers exposed to anthophyllite associated with other contaminating amphibole asbestos in Brazil.

OBJECTIVE: To evaluate the frequency and severity of pleuropulmonary alterations in anthophyllite-exposed former workers in Itapira, São Paulo, Brazil. The amphibole anthophyllite, a magnesium-iron silicate, had its mining, marketing, and use forbidden in Brazil in 1995. METHODS: Former workers were followed from 1999 to 2011. All completed chest X-ray interpreted using the International Labour Office (ILO) classification. High-resolution computed tomography was used at the final evaluation. Spirometry assessed forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and FEV1/FVC throughout the follow-up period. Samples from the mined ore were analyzed by X-ray diffraction (XRD) and scanning electron microscopy coupled to energy dispersive spectroscopy (SEM-EDS). RESULTS: XRD and SEM-EDS confirmed the presence in ore of anthophyllite at a concentration of 75%, in addition to tremolite and other amphiboles in lower concentrations. Twenty-eight subjects were evaluated. Median time of exposure was 3 years (minimum = 1; maximum = 18; interquartile interval = 1-4). Twenty cases of pleural abnormalities were diagnosed in 26 evaluated (77%). The average latency time was 25.6 ± 7.4 years. Two individuals (7.7%) showed progressive worsening of diffuse pleural thickening (DPT) and exhibited an annual FVC decrease of 85 mL and 150 mL, respectively. CONCLUSION: This small sample showed a very high index of nonmalignant pleural abnormalities in anthophyllite-exposed workers compared with workers exposed to other kinds of fibers. Rapidly progressive DPT, defined by the severity of pleural compromise, was possibly secondary to the presence of other amphibole types in the inhaled dust. No significant loss of FVC was found in the studied group as a whole. No cases of asbestosis, lung carcinoma, and mesothelioma were diagnosed in this cohort.

[Asbestos in the National Navy: Employment-exposure matrix]. / L'Amiante dans la Marine nationale : matrice emploi-exposition.

INTRODUCTION: The odd risk ratio for an asbestos-related disease is 6.9 for National Defense personnel and 94% of the victims who are compensated belong to the French Navy. While employment-exposure matrices exist for the civilian environment, none are available to the military. Our work consists of the creation of the first employment-exposure matrix in the French Navy, in order to optimize post-occupational medical surveillance. METHOD: We conducted a bibliographic search for asbestos in naval repair, naval embarking and foreign navies. From databases such as Medline, Pubmed, we used the following keywords "Navy", "Asbestos", "Shypyard" and "Military" and we have extended ourselves to the registers of existing theses on the subject. RESULTS: Epidemiological and bibliographic data confirm the increased risk in the French Navy. Three variables are important in the proposal of this employment-exposure matrix: employment, year of arming the ship and duration of embarkation. There is a major risk for personnel whose work is in direct contact with asbestos, in particular machine personnel, irrespective of their duration of exposure. For embarked personnel who do not have direct contact with asbestos in their jobs, the increase in risk depends essentially on the ship's year of arming and the presence of asbestos, whether or not on board, as well as the duration of exposure of seafarers. CONCLUSION: These results allow us to recommend a classification of the risk in accordance with the recommendations of the French Health Authority and to propose an adequate post-professional follow-up for the personnel of the Navy.