Occupational Asbestos Exposure Research Articles

Laying the Foundation for a Mesothelioma Patient Registry: Development of Data Collection Tools.

Mesothelioma, a cancer of mesothelial cells that line the chest, lungs, heart, and abdomen, is a relatively rare disease. In the United States, approximately 3000 individuals are diagnosed with mesothelioma annually. The primary risk factor for mesothelioma is occupational asbestos exposure which can occur decades prior to disease development, though in approximately 20% of cases, known asbestos exposure is lacking. While several other countries have developed mesothelioma registries to collect key clinical and exposure data elements to allow better estimation of incidence, prevalence, and risk factors associated with disease development, no national mesothelioma registry exists in the U.S. Therefore, as part of a larger feasibility study, a patient exposure questionnaire and a clinical data collection tool were created using a series of key informant interviews. Findings suggest that risk factor and clinical data collection via an on-line questionnaire is feasible, but specific concerns related to confidentiality, in the context of employer responsibility for exposure in the unique U.S. legal environment, and timing of enrollment must be addressed. Lessons learned from piloting these tools will inform the design and implementation of a mesothelioma registry of national scope.

Occupational asbestos exposure and urinary bladder cancer: a systematic review and meta-analysis

PurposeThere is conflicting evidence on the association between asbestos exposure and bladder cancer. We performed a systematic review and meta-analysis to provide evidence on occupational asbestos exposure and the risk of mortality and incidence of bladder cancer.MethodsWe searched three relevant electronic databases (Pubmed, Scopus, and Embase) from inception to October 2021. The methodological quality of included articles was evaluated using the US National Institutes of Health tool. Standardized incidence ratios (SIRs) and standardized mortality ratios (SMRs) for bladder cancer, as well as respective 95% confidence intervals (CIs), were extracted or calculated for each included cohort. Main and subgroup meta-analyses according to first year of employment, industry, sex, asbestos type, and geographic region were performed.ResultsFifty-nine publications comprising 60 cohorts were included. Bladder cancer incidence and mortality were not significantly associated with occupational asbestos exposure (pooled SIR: 1.04, 95% CI: 0.95–1.13, P = 0.000; pooled SMR: 1.06, 95% CI: 0.96–1.17, P = 0.031). Bladder cancer incidence was higher among workers employed between 1908 and 1940 (SIR: 1.15, 95% CI: 1.01–1.31). Mortality was elevated in asbestos workers cohorts (SMR: 1.12, 95% CI: 1.06–1.30) and in the subgroup analysis for women (SMR: 1.83, 95% CI: 1.22–2.75). No association was found between asbestos types and bladder cancer incidence or mortality. We observed no difference in the subgroup analysis for countries and no direct publication bias evidence.ConclusionThere is evidence that workers with occupational asbestos exposure have a bladder cancer incidence and mortality similar to the general population.

Incidence and mortality from malignant mesothelioma 1982–2020 and relationship with asbestos exposure: the Australian Mesothelioma Registry

ObjectivesMalignant mesothelioma is an uncommon cancer associated with asbestos exposure, predominantly occupational. Asbestos has been banned in Australia since 2003 but mesothelioma has a long latency and incident cases continue...

What role for asbestos in idiopathic pulmonary fibrosis? Findings from the IPF job exposures case–control study

BackgroundAsbestos has been hypothesised as the cause of the recent global increase in the incidence of ‘idiopathic’ pulmonary fibrosis (IPF). Establishing this has important diagnostic and therapeutic implications. The association...

Distinguishing Occupational and Environmental Asbestos Exposures: Case Series

Distinguishing Occupational and Environmental Asbestos Exposures: Case Series

Cytological Assessment of Desmoplastic Malignant Pleural Mesothelioma in an Autopsy Case.

Desmoplastic malignant pleural mesothelioma (DMPM) is a sarcoma-type mesothelioma, comprising approximately 5% of malignant pleural mesotheliomas. Although effusion cytology is commonly used as the primary diagnostic approach for mesothelioma, it may not be useful for DMPM because of the presence of desmoplasia and bland cellular atypia. We report a case, and previously undescribed cytological features, of DMPM that was diagnosed during autopsy. A man in his 60s with a history of occupational asbestos exposure was referred to our hospital with right chest pain. A chest CT scan showed right pleural effusion. Thirteen months later, the patient died of respiratory failure. During autopsy, scrape-imprint smears were prepared and cytology of pleural effusions was performed. The scrape-imprint smear samples showed spindle cells with mild nuclear atypia and grooves with fibrous stroma. Pleural effusion cytology revealed spindle cells with mild nuclear atypia, as well as grooves with loose epithelial connections. Histological examination of the right pleura showed spindle cells proliferating with dense collagen fibers, as seen in the cytological samples, thus indicating a diagnosis of DMPM, which was confirmed by fluorescence in situ hybridization. Cytological procedures such as pleural effusion cytology and scrape-imprinting cytology may help in diagnosing rare tumors such as DMPM.

Correlation of lung function with ultra-low-dose CT-detected lung parenchymal abnormalities: a cohort study of 1344 asbestos exposed individuals

IntroductionDeliberate exposure to medical ionising radiation should be as low as reasonably practicable but the reduction of radiation from CT should be balanced against diagnostic image quality. The ability of...

Assessment of miR-103a-3p in leukocytes-No diagnostic benefit in combination with the blood-based biomarkers mesothelin and calretinin for malignant pleural mesothelioma diagnosis.

Malignant pleural mesothelioma (MPM) is a cancer associated with asbestos exposure and its diagnosis is challenging due to the moderate sensitivities of the available methods. In this regard, miR-103a-3p was considered to increase the sensitivity of established biomarkers to detect MPM. Its behavior and diagnostic value in the Mexican population has not been previously evaluated. In 108 confirmed MPM cases and 218 controls, almost all formerly exposed to asbestos, we quantified miR-103-3a-3p levels in leukocytes using quantitative Real-Time PCR, together with mesothelin and calretinin measured in plasma by ELISA. Sensitivity and specificity of miR-103-3a-3p alone and in combination with mesothelin and calretinin were determined. Bivariate analysis was performed using Mann-Whitney U test and Spearman correlation. Non-conditional logistic regression models were used to calculate the area under curve (AUC), sensitivity, and specificity for the combination of biomarkers. Mesothelin and calretinin levels were higher among cases, remaining as well among males and participants ≤60 years old (only mesothelin). Significant differences for miR-103a-3p were observed between male cases and controls, whereas significant differences between cases and controls for mesothelin and calretinin were observed in men and women. At 95.5% specificity the individual sensitivity of miR-103a-3p was 4.4% in men, whereas the sensitivity of mesothelin and calretinin was 72.2% and 80.9%, respectively. Positive correlations for miR-103a-3p were observed with age, environmental asbestos exposure, years with diabetes mellitus, and glucose levels, while negative correlations were observed with years of occupational asbestos exposure, creatinine, erythrocytes, direct bilirubin, and leukocytes. The addition of miR-103a-3p to mesothelin and calretinin did not increase the diagnostic performance for MPM diagnosis. However, miR-103a-3p levels were correlated with several characteristics in the Mexican population.

Occupational exposure and asbestos related disease in Brazil, 2007 to 2021

Occupational asbestos exposure is a major public health problem, resulting in more than 222.000 deaths per year globally and several socioeconomic impacts. Brazil is historically one of the world’s largest producer and consumer of asbestos, which is mainly used in cement and mining activities. This work describes the notifications of work-related diseases of individuals exposed to asbestos in Brazil. Methods: We gathered data on work-related asbestos’ disease from the Notifiable Diseases Information System (Sinan) from 2007 to 2021, considering Pneumoconiosis and Cancer. Absolute and relative frequencies of sociodemographic and epidemiological characteristics were described. Results: From 2007 to 2021, 2,246 cases of work-related Pneumoconiosis and Cancer with asbestos exposure were registered. 2008 was the year with most records (n=625), followed by 2017 (n=511), with an annual average of 149 cases. Most cases occurred among male workers (96.0%), aged between 50-69y (64.5%), white (12.8%) or black (8.5%), with low educational level – up to 4 years (10.0%). Top five occupations were: workers from construction material facilities, (32,7%), urban construction (13,4%), metal handling facilities (4,3%), potters (4,2%) e masonry (3,2%). The State of São Paulo, where is located most of the companies that used asbestos in Brazil, and has relatively good surveillance of asbestos disease, concentrated 84.2% of all notified cases. Conclusions: Despite the important underreporting of chronic diseases, there is a high burden of asbestos diseases in Brazil, mainly affecting elderly men (due to the disease’s long latency) and less-skilled occupations. Thus, it is essential to strengthening public policies, health surveillance, and care, considering the particularities of asbestos-related diseases and territories.

EP16.01-004 Pleural Mesotheliomas Related with Geographical Asbestos Exposure Show Higher PD-L1 Expression

The major risk factor in diffuse pleural mesothelioma (PM) is occupational and/or geographical asbestos exposure. Surgery is a treatment option in only a limited number of cases. Prognosis is very poor with current therapies and new treatment options are needed. Immune checkpoint inhibitors (ICIs) may be a treatment option in PM, as in other malignant tumors. However, it is necessary to use predictive biomarkers to determine which patients will benefit from treatment. PD-L1 immunohistochemistry is widely used to predict therapy response to ICIs in many tumors.

Cost-Effectiveness of an Organized Lung Cancer Screening Program for Asbestos-Exposed Subjects.

Simple SummaryLung cancer screening experiments in smokers are underway in Europe, and data in populations with other risk factors for lung cancer, such as asbestos exposure, are expected. Our original article yielded a cost-effectiveness analysis of a lung cancer screening program in a population exposed to asbestos, based on the data from National Lung Cancer Screening trial and a French asbestos-exposed cohort (ARDCO cohort). Individual data from 14,218 subjects in the ARDCO cohort, followed for 20 years (2002–2022), have allowed several screening models to be established according to exposure level, smoking status and presence of radiological signs of asbestos exposure. For the whole cohort, an annual screening programme is not cost-effective, while screening every 2 years for smokers with high asbestos-exposure and subjects with asbestosis is cost-effective. This analysis has never been reported in the literature and could help in the establishment of inclusion criteria for future experiments in this population.Background: The National Lung Screening Trial (NLST) and NELSON study opened the debate on the relevance of lung cancer (LC) screening in subjects exposed to occupational respiratory carcinogens. This analysis reported the incremental cost-effectiveness ratios (ICER) of an organized LC screening program for an asbestos-exposed population. Methods: Using Markov modelization, individuals with asbestos exposure were either monitored without intervention or annual low-dose thoracic computed-tomography (LDTCT) scan LC screening. LC incidence came from a prospective observational cohort of subjects with occupational asbestos exposure. The intervention parameters were those of the NLST study. Utilities and LC-management costs came from published reports. A sensitivity analysis evaluated different screening strategies. Results: The respective quality-adjusted life year (QALY) gain, supplementary costs and ICER [95% confidence interval] were: 0.040 [0.010–0.065] QALY, 6900 [3700–11,800] € and 170,000 [75,000–645,000] €/QALY for all asbestos-exposed subjects; and 0.144 [0.071–0.216] QALY, 13,000 [5700–26,800] € and 90,000 [35,000–276,000] €/QALY for smokers with high exposure. When screening was based on biennial LDTCT scans, the ICER was 45,000 [95% CI: 15,000–116,000] €/QALY. Conclusions: Compared to the usual ICER thresholds, biennial LDTCT scan LC screening for smokers with high occupational exposure to asbestos is acceptable and preferable to annual scans.

Pleural plaques and risk of lung cancer in workers formerly occupationally exposed to asbestos: extension of follow-up

BackgroundOccupational asbestos exposure is associated with pleural plaques (PP), a benign disease often seen as a marker of past exposure to asbestos and lung cancer. The association between these two...

Lung cancer and mesothelioma risks in a prospective cohort of workers with asbestos-related lung or pleural diseases.

Asbestos causes mesothelioma and lung cancer. In the European Union, asbestos was banned in 2005, but it is still in use in many other countries. The aim of this study was to estimate the lung cancer and mesothelioma incidence risk of men with benign asbestos-related lung or pleural diseases. Between 2008 and 2018, 2439 male participants of a German surveillance program for asbestos workers were included in the cohort. All participants had a recognized occupational asbestos-related disease of the pleura or lung. We estimated the mesothelioma and lung cancer risks by calculating standardized incidence ratios (SIR) with corresponding 95% confidence intervals (95% CI). We observed 64 incident lung cancer and 40 mesothelioma cases in the cohort. An SIR of 17.60 (95% CI: 12.57-23.96) was estimated for mesothelioma and 1.27 (95% CI: 0.98-1.62) for lung cancer. The presence of pleural plaques was associated with a strongly increased risk (SIR: 13.14; 95% CI: 8.51-19.40) for mesothelioma, but not for lung cancer (SIR: 1.05; 95% CI: 0.76-1.41). The highest lung-cancer risk (SIR: 2.56; 95% CI 1.10-5.04) was revealed for cohort members with less than 40 years since first asbestos exposure. Lung cancer risks by duration of asbestos exposure did not show a consistent time trend, but for time since last exposure a trend for mesothelioma was seen. Compared to the general population, we demonstrated an association between benign asbestos-related lung or pleural disease and mesothelioma risk in workers with a history of occupational asbestos exposure. Because lung-cancer risk is dominated by smoking habits, a possible effect of asbestos exposure may have been masked. Efforts should be made to ban production and use of asbestos worldwide and to establish safe handling rules of legacy asbestos.

Malignant Mesothelioma Mortality in Women - United States, 1999-2020.

Inhalation of asbestos fibers can cause malignant mesothelioma, a rapidly progressing and lethal cancer of the mesothelium, the thin layer of tissues surrounding internal organs in the chest and abdomen. Patients with malignant mesothelioma have a poor prognosis, with a median survival of 1 year from diagnosis. The estimated median interval from initial occupational asbestos exposure to death is 32 years (range = 13-70 years) (1). Occupational asbestos exposure is most often reported in men working in industries such as construction and manufacturing; however, women are also at risk for exposure to asbestos fibers, and limited data exist on longer-term trends in mesothelioma deaths among women. To characterize deaths associated with mesothelioma and temporal trends in mesothelioma mortality among women in the United States, CDC analyzed annual Multiple Cause of Death records from the National Vital Statistics System for 1999-2020, the most recent years for which complete data are available. The annual number of mesothelioma deaths among women increased significantly, from 489 in 1999 to 614 in 2020; however, the age-adjusted death rate per 1 million women declined significantly, from 4.83 in 1999 to 4.15 in 2020. The largest number of deaths was associated with the health care and social assistance industry (89; 15.7%) and homemaker occupation (129; 22.8%). Efforts to limit exposure to asbestos fibers, including among women, need to be maintained.

Pulmonary Asbestos Fiber Burden Is Related to Patient Survival in Malignant Pleural Mesothelioma

IntroductionMalignant pleural mesothelioma (MPM) is associated with poor prognosis and is strongly associated with occupational asbestos exposure. Given the importance of asbestos exposure in MPM pathogenesis, we retrospectively analyzed the types and concentrations of asbestos fibers within the lung tissues of patients with MPM and investigated their effects on all-cause mortality. MethodsWe formed a national data set of patients with MPM identified from the Finnish Cancer Registry and Statistics Finland. These data were merged with pulmonary asbestos fiber analysis results received from the Finnish Institute of Occupational Health. ResultsWe identified 590 patients with MPM who underwent pulmonary asbestos fiber analysis. The median asbestos concentration within dry lung tissue was 3.20 million fibers/gram (range: 0 − 1700 million fibers/gram). Crocidolite and anthophyllite were the most prevalent asbestos fiber types detected in lung tissue. The multivariable risk of death analyses, where changes over time were accounted for, revealed that total asbestos fiber concentration was associated with increased mortality. Nevertheless, no difference in mortality was noted between different fiber types. ConclusionsOur study revealed that pulmonary fiber concentrations correlated with the manner of asbestos usage. Anthophyllite was identified as the sole fiber in a sizable proportion of cases, supporting its independent role in the pathogenesis of MPM. Our findings suggest that asbestos fiber burden, but not fiber type, may have an impact on the prognosis of MPM.

Asbestos Exposure in Patients with Malignant Pleural Mesothelioma included in the PRIMATE Study, Lombardy, Italy.

The PRIMATE study is an Italian translational research project, which aims to identify personalized biomarkers associated with clinical characteristics of malignant pleural mesothelioma (MPM). For this purpose, characteristics of MPM patients with different degrees of asbestos exposure will be compared to identify somatic mutations, germline polymorphism, and blood inflammatory biomarkers. In this framework, we assessed exposure to asbestos for 562 cases of MPM extracted from the Lombardy region Mesothelioma Registry (RML), for which a complete interview based on a standardized national questionnaire and histopathological specimens were available. Exposure assessment was performed: (1) through experts' evaluation (considered as the gold standard for the purpose of this study), according to the guidelines of the Italian National Mesothelioma Registry (ReNaM) and (2) using a job-exposure matrix (SYN-JEM) to obtain qualitative (ever/never) and quantitative estimates of occupational asbestos exposure (cumulative exposure expressed in fibers per mL (f/mL)). The performance of SYN-JEM was evaluated against the experts' evaluation. According to experts' evaluation, occupational asbestos exposure was recognized in 73.6% of men and 23.6% of women; furthermore, 29 men (7.8%) and 70 women (36.9%) had non-occupational exposure to asbestos. When applying SYN-JEM, 225 men (60.5%) and 25 women (13.2%) were classified as occupationally exposed, with a median cumulative exposure higher for men (1.7 f/mL-years) than for women (1.2 f/mL-years). The concordance between the two methods (Cohen’s kappa) for occupational exposure assessment was 0.46 overall (0.41 in men, and 0.07 in women). Sensitivity was higher in men (0.73) than in women (0.18), while specificity was higher in women (0.88) than in men (0.74). Overall, both methods can be used to reconstruct past occupational exposure to asbestos, each with its own advantages and limitations.

Explaining the Invisibility of Asbestos-Related Diseases in the Taiwan Workers' Compensation System.

Occupational asbestos exposure was prevalent in Taiwan, but asbestos-related diseases (ARDs) have rarely been recognized. We conducted in-depth face-to-face interviews with 16 patients with ARDs. All of them had worked in industries known for high asbestos exposure. However, only three patients had filed workers' compensation (WC) claims, and of them, only two patients were approved. Reasons for the low compensation rate of ARDs could be divided into institutional barriers related to the flaws of the WC system and non-institutional barriers related to the knowledge status, causal interpretation, and social situations of individual workers. The Labor Occupational Accident Insurance and Protection Act passed in April 2021 has responded to the under-compensation of occupational diseases. However, the new act's effects toward improving the recognition of ARDs remain questionable. Our findings indicated that additional efforts are needed to remove non-institutional barriers hindering workers' ability to ensure their compensation rights.

Job Exposure Matrix for Chrysotile Asbestos Fibre in the Asbestos Cement Manufacturing (ACM) Industry in Zimbabwe.

Occupational chrysotile asbestos exposure data in Zimbabwe is limited. The aim of this study was therefore to develop a job exposure matrix (JEM) specific to the chrysotile asbestos cement manufacturing industry using the available personal exposure concentration data. Quantitative personal exposure chrysotile fibre concentration data collected by the two factories from 1996 to 2020 were used to construct the JEM. Exposure groups from which data was extracted were classified based on the Zimbabwe Standard Classification of Occupations (ZSCO), 2009–2019. Analysis of amphiboles in raw chrysotile was done by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Descriptive statistics, namely mean, standard deviation and range were computed for the main variable, job/occupation. All jobs/occupations in both factories had annual mean personal exposure concentrations exceeding the OEL of 0.1 f/mL, except for the period from 2009 to 2016 in the Harare factory and the period from 2009 to 2020 in the Bulawayo factory. Despite the Harare factory having no AC manufacturing activity since 2017, personal exposure concentrations showed elevated levels for the period 2018–2020. Amphiboles were detected in almost all bulk samples of chrysotile asbestos analysed. The established JEM, which has been generated from actual local quantitative exposure measurements, can be used in evaluating historical exposure to chrysotile asbestos fibre, to better understand and predict occurrence of ARDs in future.

A Cohort Study on Cancer Incidence among Women Exposed to Environmental Asbestos in Childhood with a Focus on Female Cancers, including Breast Cancer.

Objectives: To examine the risk of cancer in former school children exposed to environmental asbestos in childhood with a focus on female cancers, including breast cancer. Methods: We retrieved a cohort of females (n = 6024) attending four schools located in the neighborhood of a large asbestos cement plant in Denmark. A reference cohort was frequency-matched 1:9 (n = 54,200) in sex and five-year age intervals. Using Danish registries, we linked information on historical employments, relatives’ employments, cancer, and vital status. We calculated standardized incidence rates (SIRs) for all and specific cancers, comparing these rates with the reference cohort. Hazard ratios were calculated for selected cancers adjusted for occupational and familial asbestos exposure. Results: For cancer of the corpus uteri (SIR 1.29, 95% CI 1.01–1.66) and malignant mesothelioma (SIR 7.26, 95% CI 3.26–16.15), we observed significantly increased incidences. Occupationally, asbestos exposure had a significantly increased hazard ratio for cancer in the cervix, however, a significantly lower risk of ovarian cancer. The overall cancer incidence was similar to that of the reference cohort (SIR 1.02, 95% CI 0.96–1.07). The risk of cancer of the lung was increased for those exposed to occupational asbestos, those with family members occupationally exposed to asbestos and for tobacco smokers. Conclusions: In our study, environmental asbestos exposure in childhood is associated with an increased risk of cancer of the corpus uteri and malignant mesothelioma in women.

Global Magnitude and Temporal Trend of Mesothelioma Burden Along with the Contribution of Occupational Asbestos Exposure in 204 Countries and Territories from 1990 to 2019: Results from the Global Burden of Disease Study 2019

Global Magnitude and Temporal Trend of Mesothelioma Burden Along with the Contribution of Occupational Asbestos Exposure in 204 Countries and Territories from 1990 to 2019: Results from the Global Burden of Disease Study 2019