The diagnosis of asbestosis in the 21st century: a clinicopathological correlation of 102 cases

Asbestosis, defined as diffuse pulmonary fibrosis caused by inhalation of asbestos fibers, occurs after heavy exposures to asbestos dust over several decades. Because workplace exposures have been significantly curtailed since the banning of asbestos in insulation products, we were interested in examining the clinicopathological characteristics of cases diagnosed in the 21st century. The consultation files of one of the authors (VLR) were reviewed for cases of asbestosis diagnosed since 1/1/2001. 102 cases were identified, with a median age of 75 years (range: 45-89). There were 100 men and 2 women. The women were from Turkey and Brazil (none from the United States). Malignancies were present in 78 cases, including 38 lung cancers, 29 pleural mesotheliomas, and 8 peritoneal mesotheliomas. The grade of asbestosis was available in 88 cases (median severity of 2; scale: 1-4). Pleural plaque was present in 94% of cases. The most common exposure categories were insulators (39), shipyard workers (16), asbestos manufacturing (9), boiler workers (8) and pipefitter/welders (6). The median duration of exposure was 33 years (range: 2-49 years). Lung fiber burden analysis was performed in 34 cases, with amosite being the predominant fiber type. Results were compared with similar information for 475 cases diagnosed prior to 1/1/2001.

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.

Occupational interstitial lung diseases

Millions of workers are exposed to substances known to cause occupational interstitial lung diseases (ILDs), particularly in developing countries. However, the burden of the disease is likely to be underestimated due to under-recognition, under-reporting or both. The diagnosis of occupational ILD requires a high level of suspicion and a thorough occupational history, as occupational and non-occupational ILDs may be clinically, functionally and radiologically indistinguishable, leading to delayed diagnosis and inappropriate management. A potential occupational aetiology should always be considered in the differential diagnosis of ILD, as removal from the workplace exposure, with or without treatment, is a key therapeutic intervention and may lead to significant improvement. In this article, we provide an overview of the 'traditional' inorganic dust-related ILDs but also address idiopathic pulmonary fibrosis and the immunologically mediated chronic beryllium disease, sarcoidosis and hypersensitivity pneumonitis, with emphasis on the importance of surveillance and prevention for reducing the burden of these conditions. To this end, health-care professionals should be specifically trained about the importance of occupational exposures as a potential cause of ILD.

Pneumoconiosis incidence and prevalence among US Medicare beneficiaries, 1999-2019

BACKGROUND

Pneumoconiosis is a group of occupational lung diseases caused by dust and fiber exposure. This study analyzes Medicare claims to estimate the burden of pneumoconiosis among fee-for-service (FFS; Medicare Parts A and B) Medicare beneficiaries during 1999-2019 in the United States.

METHODS

Claim and enrollment information from 81 million continuously enrolled FFS Medicare beneficiaries were analyzed. Beneficiaries with any pneumoconiosis and cause-specific pneumoconiosis (e.g., asbestosis, silicosis) were identified using three case definitions (broad, intermediate, and narrow) with varying diagnostic criteria based on claim International Classification of Diseases, Clinical Modification (ICD-CM) diagnosis codes and Healthcare Common Procedure Coding System codes. Results are presented as ranges of values for the three case definitions.

RESULTS

The 21-year prevalence range for any pneumoconiosis was 345,383-677,361 (412-833 per 100,000 beneficiaries) using the three case definitions. The highest prevalence was among those ≥75 years of age, males, Whites, and North American Natives. Most claims (70.0%-72.5%) included an ICD-CM diagnosis code for asbestosis. The broad pneumoconiosis prevalence rate increased significantly (p < 0.001) during 2002-2009 by 3%-10% annually and declined significantly by 3%-5% annually starting in 2009. The average annual broad incidence rate declined significantly by 7% annually during 2009-2019.

CONCLUSIONS

Despite the decline in rate for any pneumoconiosis among Medicare beneficiaries, which is primarily attributed to a decline in asbestosis, pneumoconiosis is prevalent among FFS Medicare beneficiaries.

The incidence of malignancies in asbestosis with chrysotile exposure: a large Chinese prospective cohort study

Background

Asbestos exposure is closely related to the occurrence and development of various malignancies. This prospective cohort study aimed to evaluate the incidence rate and potential risk factors in a cohort of asbestosis patients in China.

Methods

The incidence of malignancies was determined in patients who had been exposed to chrysotile asbestos and diagnosed with asbestosis sequentially at Beijing Chaoyang Hospital from 1 January 2007 to 31 December 2019. Cox regression analyses were used to analyze the correlations between clinical variables and asbestosis combined with malignancies.

Results

A total of 618 patients with asbestosis were identified, of whom 544 were eligible for analysis. Among them, 89 (16.36%) were diagnosed with various malignancies. The standardized incidence ratios (SIRs) of patients with asbestosis combined with malignancies were 16.61, 175, 5.23, and 8.77 for lung cancer, mesothelioma, breast cancer, and endometrial carcinoma, respectively. The risks of all malignancies and lung cancer increased with initial exposure before 17 years old, longer asbestos exposure, and smoking.

Conclusions

The SIRs of patients with asbestosis-related malignancies were significantly increased in lung cancer, mesothelioma, breast cancer, and endometrial carcinoma in a hospital-based Chinese cohort. Smoking and the duration of asbestos exposure increased the risk of lung cancer.

Asbestos Exposure and Development of Pulmonary Pleomorphic Carcinoma in a Non-smoker: A Rare Non-small Cell Lung Cancer

Pulmonary pleomorphic carcinoma (PPC) is a subtype of non-small cell lung cancer that is extremely rare and carries a poor prognosis due to its inadequate response to treatment. Patients that present with PPC often exhibit similar symptoms of other malignancies of the lung, making it hard for clinicians to distinguish between each type. However, cytology and gene mutation testing are two approaches that can aid physicians in an accurate and definitive diagnosis. We present a case of an 88-year-old male patient with a diagnosis of pulmonary pleomorphic carcinoma after experiencing recurrent sanguineous pleural effusions. The patient had no smoking history but did have a history of asbestos exposure and pulmonary fibrosis. The patient underwent thoracotomy with pleurodesis and analysis of the surgical pleural biopsy specimen stained positive for markers indicative of PPC. The pathology report was also consistent with the associated cell morphology. Lung cancer is the leading cause of mortality due to cancer in the United States, and exposure to certain substances contributes to the development of these poorly treatable lung malignancies. Smoking and asbestos exposure are well known to act synergistically with each other as risk factors in developing these lung malignancies. In addition to clinical suspicion, screening for these risk factors with laboratory values and imaging is important to diagnose these rare cases of lung malignancies.

Does the Presence of Asbestos-Containing Materials in Buildings Post-construction and Before Demolition Have an Impact on the Exposure to Occupants in Non-occupational Settings?

This narrative review aims to determine if asbestos-containing materials in buildings pose a hazard to building occupants in non-occupational settings. This paper is limited to the post-construction and pre-demolition stages of a building. The researchers selected 19 studies from the 126 studies screened, concerning exposure to asbestos fibers in non-occupational building settings, with a focus on post-construction and pre-demolition phases. The literature review found that certain conditions, such as the measurement techniques, standards, and previous data availability, prevent a conclusive answer to the research question. Some studies have pointed towards an effect of asbestos-containing materials on health of occupants in non-occupational settings. But, there are some that do not suggest a positive relationship between non-occupational exposure and the presence of asbestos-containing materials, and therefore these provide scope for further research, as these studies also do not rule out the relationship completely. The present study highlights the gaps in current knowledge and indicates areas for further research. Until conclusive evidence based on revised threshold standards and accurate measurement techniques is available, asbestos-containing materials may be considered unsafe for use in non-occupational settings, especially ones that young people and children occupy.

The Brazilian System for Monitoring Workers and General Population Exposed to Asbestos: Development, Challenges, and Opportunities for Workers' Health Surveillance

The lack of safe levels of asbestos exposure and the long latency of asbestos-related disease (ARD) makes workers' health surveillance challenging, especially in lower-income countries. This paper aims to present the recently developed Brazilian system for monitoring workers and general population exposed to asbestos (Datamianto), and to discuss the main challenges and opportunities for workers' health surveillance.

METHODS

a descriptive study of the Datamianto development process, examining all the stages of system planning, development, improvement, validation, availability, and training of health services for its use, in addition to presenting the main challenges and opportunities for its implementation.

RESULTS

The system was developed by a group of software developers, workers' health specialists, and practitioners, and it was recently incorporated by the Ministry of Health to be used for workers' health surveillance. It can facilitate the monitoring of exposed individuals, epidemiological data analysis, promote cooperation between health services, and ensure periodical medical screening guaranteed to workers by labor legislation. Moreover, the system has a Business Intelligence (BI) platform to analyze epidemiologic data and produce near real-time reports.

CONCLUSIONS

Datamianto can support and qualify the healthcare and surveillance of asbestos-exposed workers and ARD, promoting a better quality of life for workers and improving companies' compliance with legislation. Even so, the system's significance, applicability, and longevity will depend on the efforts aimed at its implementation and improvement.

Mortality of 196,826 Men and Women Working in U.S.-Based Petrochemical and Refinery Operations: Update 1979 to 2010

OBJECTIVE

To describe mortality trends of men and women working in various petrochemical and refinery operations of a U.S.-based company.

METHODS

The cohort consists of full-time employees with at least 1 day of service during 1979 through 2010. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated for 111 possible causes of death studied.

RESULTS

SMRs for malignant mesothelioma and asbestosis were highest for the 1940s decade of hire. Increased SMRs were observed for malignant melanoma and motor neuron disease with no obvious work patterns. Decreasing mortality patterns were observed for aplastic anemia and acute nonlymphocytic leukemia.

CONCLUSIONS

Mortality surveillance of this large established cohort aids in assessing the chronic health status of the workforce. Identifying methods for incorporating job-exposure matrices and nonoccupational risk factors could further enhance interpretations for some findings such as motor neuron disease.

Burden of Mortality from Asbestos-Related Diseases in Italy

Asbestos is one of the major worldwide occupational carcinogens. The global burden of asbestos-related diseases (ARDs) was estimated around 231,000 cases/year. Italy was one of the main European asbestos producers until the 1992 ban. The WHO recommended national programs, including epidemiological surveillance, to eliminate ARDs. The present paper shows the estimate of the burden of mortality from ARDs in Italy, established for the first time. National standardized rates of mortality from mesothelioma and asbestosis and their temporal trends, based on the National Institute of Statistics database, were computed. Deaths from lung cancer attributable to asbestos exposure were estimated using population-based case-control studies. Asbestos-related lung and ovarian cancer deaths attributable to occupational exposure were estimated, considering the Italian occupational cohort studies. In the 2010-2016 period, 4400 deaths/year attributable to asbestos were estimated: 1515 from mesothelioma, 58 from asbestosis, 2830 from lung and 16 from ovarian cancers. The estimates based on occupational cohorts showed that each year 271 deaths from mesothelioma, 302 from lung cancer and 16 from ovarian cancer were attributable to occupational asbestos exposure in industrial sectors with high asbestos levels. The important health impact of asbestos in Italy, 10-25 years after the ban, was highlighted. These results suggest the need for appropriate interventions in terms of prevention, health care and social security at the local level and could contribute to the global estimate of ARDs.

Underreporting of mesothelioma, asbestosis and pleural plaques in Brazil

BACKGROUND

Brazil has a long history of heavy asbestos consumption. However, the number of asbestos-related diseases (ARDs) falls far below the one expected compared with other asbestos consumer countries.

AIMS

To examine underreporting of ARDs, that is mesothelioma, asbestosis and pleural plaques, in Brazil's Mortality Information System (SIM).

METHODS

Health information systems (HIS) were mapped, datasets retrieved and records of ARD deaths extracted. Records were pair-matched using anonymous linkage to create a single database. ARD-reported cases missing in SIM were considered unreported. The study's period ranged from 2008 to 2014, when every HIS contributed to the ARD records pool.

RESULTS

A total of 1298 registered ARD deaths were found, 996 cases of mesothelioma (77%) and 302 (23%) of asbestosis and pleural plaques. SIM was the major single data source of ARD but 335 mesothelioma deaths were missing, an average underreporting of 33%, with no clear time trend. For asbestosis and pleural plaques, underreporting of ARD oscillated from 55% in 2010 to 25% in 2014, a declining trend. ARD underreporting was not associated with sex or age.

CONCLUSIONS

One-third of underreported ARD deaths in the universal SIM is unacceptably high and, apparently, it has not been improving substantially over time. After recoveries from multiple databases, the number of cases is still below, which could be expected based on asbestos consumption. Interoperability of multiple information systems could enhance case detection and improve the precision of mortality estimates, which are crucial for surveillance and for evaluation of remedial policies.

Interstitial Lung Abnormalities Detected by CT in Asbestos-Exposed Subjects Are More Likely Associated to Age

Objective: the aim of this study was to evaluate the association between interstitial lung abnormalities, asbestos exposure and age in a population of retired workers previously occupationally exposed to asbestos. Methods: previously occupationally exposed former workers to asbestos eligible for a survey conducted between 2003 and 2005 in four regions of France, underwent chest CT examinations and pulmonary function testing. Industrial hygienists evaluated asbestos exposure and calculated for each subject a cumulative exposure index (CEI) to asbestos. Smoking status information was also collected in this second round of screening. Expert radiologists performed blinded independent double reading of chest CT-scans and classified interstitial lung abnormalities into: no abnormality, minor interstitial findings, interstitial findings inconsistent with UIP, possible or definite UIP. In addition, emphysema was assessed visually (none, minor: emphysema <25%, moderate: between 25 and 50% and severe: >50% of the lung). Logistic regression models adjusted for age and smoking were used to assess the relationship between interstitial lung abnormalities and occupational asbestos exposure. Results: the study population consisted of 2157 male subjects. Interstitial lung abnormalities were present in 365 (16.7%) and emphysema in 444 (20.4%). Significant positive association was found between definite or possible UIP pattern and age (OR adjusted =1.08 (95% CI: 1.02–1.13)). No association was found between interstitial abnormalities and CEI or the level of asbestos exposure. Conclusion: presence of interstitial abnormalities at HRCT was associated to aging but not to cumulative exposure index in this cohort of former workers previously occupationally exposed to asbestos.

Low dose CT detected interstitial lung abnormalities in a population with low asbestos exposure

BACKGROUND

The use of low dose CT (LDCT) chest is becoming more widespread in occupationally exposed populations. There is a knowledge gap as to heterogeneity in severity and the natural course of asbestosis after low levels of exposure. This study reports the characteristics of LDCT-detected interstitial lung abnormalities (ILA).

METHODS

The Asbestos Review Program offers annual LDCT, health assessments, and pulmonary function tests to an asbestos-exposed cohort. Asbestosis was defined using the Helsinki Consensus statement and the presence of ILA defined using a protocol for occupational CT reports. At least two of three pulmonary function tests: forced expiratory volume in 1 s (FEV₁ );​ forced vital capacity (FVC); and diffusion capacity for carbon monoxide (DLco) were required for analysis of physiological decline.

RESULTS

From 1513 cases, radiological ILA was present in 485 (32%). The cohort was 83.5% male with a median age of 68.3 years and a median (IQR) asbestos exposure of 0.7 (0.09-2.32) fiber/ml-year. A mixed occupation, mixed asbestos fiber cohort comprised the majority of the cohort (65.8%). Of those with ILA, 40 (8.2%) had an FVC decline of ≥10% and 30 (6.2%) had a DLco decline of ≥15% per year. Time since first exposure, increasing tobacco exposure and reported dyspnea were independently associated with the presence of ILA.

CONCLUSIONS

In this population with relatively low asbestos exposure, LDCT-detected ILA that fits criteria for asbestosis is common, but physiological decline is not. This mild chronic stable phenotype of asbestos-associated ILA contrasts with the traditionally accepted views that asbestosis requires high exposures.

Incidence of mesothelioma and asbestosis by occupation in a diverse workforce

OBJECTIVE

We sought to characterize detailed patterns of mesothelioma and asbestosis incidence in the workforce as part of an occupational disease surveillance program in Ontario, Canada.

METHODS

The Occupational Disease Surveillance System (ODSS) cohort was established using workers' compensation claims data and includes 2.18 million workers employed from 1983 to 2014. Workers were followed for mesothelioma and asbestosis diagnoses in Ontario Cancer Registry, physician, hospital, and ambulatory care records through 2016. Trends in incidence rates were estimated over the study period. Cox proportional hazard models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A total of 854 mesothelioma and 737 asbestosis cases were diagnosed during follow-up. Compared with all other workers in the ODSS, those employed in construction trades occupations had the greatest adjusted incidence rate of both mesothelioma (223 cases; HR, 2.38; 95% CI: 2.03-2.78) and asbestosis (261 cases; HR, 3.64; 95% CI: 3.11-4.25). Rates were particularly elevated for insulators, pipefitters and plumbers, and carpenters. Workers in welding and flame cutting, boiler making, and mechanic and machinery repair occupations, as well as those in industrial chemical and primary metal manufacturing industries, had strongly elevated rates of both diseases. Rates were greater than anticipated for workers in electrical utility occupations and education and related services.

CONCLUSIONS

Results substantiate the risk of mesothelioma and asbestosis in occupation and industry groups in the Ontario workforce with known or suspected asbestos exposure. Sustained efforts to prevent the occurrence of additional cases of disease in high-risk groups are warranted.

"Omental Cake" in a Patient With Asbestosis Leading to the Diagnosis of Malignant Peritoneal Mesothelioma

We report a case of a 68-year-old man with medical history of pleural asbestosis and diagnosed with malignant peritoneal mesothelioma. This neoplasm is rare, has a poor prognosis, and is associated with asbestosis in many cases. It manifests clinically insidiously and in relation to the intra-abdominal locoregional effect. Radiological findings are variable, although the finding of "omental cake" by CT scan is characteristic but not pathognomonic, as seen in our case. A biopsy is required for the diagnosis, which can be guided by radiology or surgery. Treatment options available are cytoreductive surgery with intraperitoneal hyperthermic chemotherapy or systemic chemotherapy. However, new therapeutic options are emerging, which are still under development and research.

Asbestosis Mimicking Metastatic Lung Cancer: Case Report

The clinical diagnosis of asbestosis is primarily based on chest radiographic evidence of pleural thickening and interstitial fibrosis combined with a history of exposure to asbestos. We report herein the case of a 65-year-old man with asbestosis pathologically diagnosed after surgical lung biopsy. He had a work history including farming, cementing, and casting and was admitted with dyspnea. Chest computed tomography revealed multiple well-defined nodules in both lungs and a 4.1 cm peribronchial consolidation with fibrotic changes in the right lower lobe. We suspected metastatic lung cancer and video-assisted thoracoscopic biopsy was performed in the lung lesion of the right lower lobe. Asbestosis was confirmed following histological examination. The patient is currently completing outpatient visits without significant changes.

The role of polymorphisms in glutathione-related genes in asbestos-related diseases

BACKGROUND

The study investigated the influence of GCLC, GCLM, GSTM1, GSTT1 and GSTP1 polymorphisms, as well as the influence of interactions between polymorphism and interactions between polymorphisms and asbestos exposure, on the risk of developing pleural plaques, asbestosis and malignant mesothelioma (MM).

SUBJECTS AND METHODS

The cross sectional study included 940 asbestos-exposed subjects, among them 390 subjects with pleural plaques, 147 subjects with asbestosis, 225 subjects with MM and 178 subjects with no asbestos-related disease. GCLC rs17883901, GCLM rs41303970, GSTM1 null, GSTT1 null, GSTP1 rs1695 and GSTP1 rs1138272 genotypes were determined using PCR based methods. In statistical analysis, logistic regression was used.

RESULTS

GSTT1 null genotype was associated with the decreased risk for pleural plaques (OR = 0.63; 95% CI = 0.40-0.98; p = 0.026) and asbestosis (OR = 0.51; 95% CI = 0.28-0.93; p = 0.028), but not for MM. A positive association was found between GSTP1 rs1695 AG + GG vs. AA genotypes for MM when compared to pleural plaques (OR = 1.39; 95% CI = 1.00-1.94; p = 0.049). The interactions between different polymorphisms showed no significant influence on the risk of investigated asbestos-related diseases. The interaction between GSTT1 null polymorphism and asbestos exposure decreased the MM risk (OR = 0.17; 95% CI = 0.03-0.85; p = 0.031).

CONCLUSIONS

Our findings suggest that GSTT1 null genotype may be associated with a decreased risk for pleural plaques and asbestosis, may modify the association between asbestos exposure and MM and may consequently act protectively on MM risk. This study also revealed a protective effect of the interaction between GSTP1 rs1695 polymorphism and asbestos exposure on MM risk.

Sensitive Blood-Based Detection of Asbestos-Associated Diseases Using Cysteine-Rich Angiogenic Inducer 61 as Circulating Protein Biomarker

BACKGROUND

Detection of asbestos-associated diseases like asbestosis or mesothelioma is still challenging. We sought to improve the diagnosis of benign asbestos-associated disease (BAAD) by detection of the protein cysteine-rich angiogenic inducer 61 (Cyr61) in human plasma.

METHODS

Plasma Cyr61 was quantified using an enzyme-linked immunosorbent assay. Plasma samples from males diagnosed with BAAD, but without a malignant disease (n = 101), and malignant mesothelioma (n = 21; 15 males, 6 females), as well as nonasbestos-exposed healthy control participants (n = 150; 58 males, 92 females) were analyzed. Clinical sensitivity and specificity of Cyr61 were determined by receiver operating characteristic analysis.

RESULTS

The median plasma Cyr61 concentration for healthy control participants was 0.27 ng/mL. Cytoplasmic Cyr61 in peripheral blood mononuclear cells from healthy control participants was evenly distributed, as detected by immunofluorescent staining. The increase in plasma Cyr61 concentrations in the BAAD study group was statistically significant compared to the healthy control participants (P < 0.0001). For the detection of BAAD vs male healthy control participants, clinical sensitivity was 88% and clinical specificity 95% with an area under the curve of 0.924 at maximal Youden Index. For a predefined clinical specificity of 100%, the clinical sensitivity was 76%. For male mesothelioma patients vs male healthy control participants, the clinical sensitivity at maximal Youden Index was 95% with a clinical specificity of 100% (area under the curve, 0.997) and for a predefined clinical specificity of 100%, the clinical sensitivity was 93%.

CONCLUSIONS

In our study, plasma Cyr61 protein concentrations showed to be a new biomarker for asbestos-associated diseases like BAAD and mesothelioma in men, which deserves further investigation in large-scale cohort studies.

Factors Affecting Asbestosis Mortality Among Asbestos-Cement Workers in Italy

OBJECTIVES

This study was performed with the aim of investigating the temporal patterns and determinants associated with mortality from asbestosis among 21 cohorts of Asbestos-Cement (AC) workers who were heavily exposed to asbestos fibres.

METHODS

Mortality for asbestosis was analysed for a cohort of 13 076 Italian AC workers (18.1% women). Individual cumulative asbestos exposure index was calculated by factory and period of work weighting by the different composition of asbestos used (crocidolite, amosite, and chrysotile). Two different approaches to analysis, based on Standardized Mortality Ratios (SMRs) and Age-Period-Cohort (APC) models were applied.

RESULTS

Among the considered AC facilities, asbestos exposure was extremely high until the end of the 1970s and, due to the long latency, a peak of asbestosis mortality was observed after the 1990s. Mortality for asbestosis reached extremely high SMR values [SMR: males 508, 95% confidence interval (CI): 446-563; females 1027, 95% CI: 771-1336]. SMR increased steeply with the increasing values of cumulative asbestos exposure and with Time Since the First Exposure. APC analysis reported a clear age effect with a mortality peak at 75-80 years; the mortality for asbestosis increased in the last three quintiles of the cumulative exposure; calendar period did not have a significant temporal component while the cohort effect disappeared if we included in the model the cumulative exposure to asbestos.

CONCLUSIONS

Among heaviest exposed workers, mortality risk for asbestosis began to increase before 50 years of age. Mortality for asbestosis was mainly determined by cumulative exposure to asbestos.

Pleural Plaques and the Risk of Lung Cancer in Asbestos-exposed Subjects

Rationale: Asbestos exposure is associated with a dose-dependent risk of lung cancer. The association between lung cancer and the presence of pleural plaques remains controversial.

Objectives: To define the relationship between pleural plaques and lung cancer risk.

Methods: Subjects were from two cohorts: 1) crocidolite mine and mill workers and Wittenoom Township residents and 2) a mixed-asbestos-fiber, mixed-occupation group. All subjects underwent annual review since 1990, chest X-ray or low-dose computed tomography scan, and outcome linkage to national cancer and mortality registry data. Cox regression, with adjustment for age (as the underlying matching time variable), was used to estimate hazard ratios (HRs) for lung cancer incidence by sex, tobacco smoking, asbestos exposure, presence of asbestosis, and pleural plaques.

Measurements and Main Results: For all 4,240 subjects, mean age at follow up was 65.4 years, 3,486 (82.0%) were male, 1,315 (31.0%) had pleural plaques, and 1,353 (32.0%) had radiographic asbestosis. Overall, 3,042 (71.7%) were ever-smokers with mean tobacco exposure of 33 pack-years. In total, 200 lung cancers were recorded. Risk of lung cancer increased with cumulative exposure to cigarettes, asbestos, and presence of asbestosis. Pleural plaques did not confer any additional lung cancer risk in either cohort (cohort 1: HR, 1.03; 95% confidence interval, 0.64-1.67; P = 0.89; cohort 2: HR, 0.75; 95% confidence interval, 0.45-1.25; P = 0.28).

Conclusions: The presence of pleural plaques on radiologic imaging does not confer additional increase in the risk of lung cancer. This result is consistent across two cohorts with differing asbestos fiber exposures and intensity.

Prognosis and causes of death of patients with acute exacerbation of fibrosing interstitial lung diseases

BACKGROUND

The aim of this study was to compare the clinical characteristics, causes of death and factors impacting on the prognosis of patients with idiopathic pulmonary fibrosis (IPF) and other fibrosing interstitial lung disease (FILD) with a history of acute exacerbation (AE) of IPF or FILD.

METHODS

Retrospective data of hospital treatment periods caused by AE-IPF and AE-FILD were collected from medical records. Clinical features and survival data of IPF and non-IPF cases were evaluated and compared. The underlying and immediate causes of death were gathered from death certificates.

RESULTS

A total of 128 patients fulfilled the criteria for inclusion. IPF (n=79/62%), rheumatoid arthritis-associated interstitial lung disease (RA-ILD; n=17/14%) and asbestosis (n=11/8.6%) were the most common FILD subgroups in the study. The median survival after hospitalisation in AE-IPF was 2.6 months compared with 21 months in other AE-FILDs (p<0.001). The survival difference was not explained by age, gender or pulmonary function test results at the time of hospitalisation. Patients with non-specific interstitial pneumonia and RA-ILD had the most favourable prognosis. ILD was the most common underlying cause of death in both patients with IPF and with other FILD accounting for 87% and 78% of deaths, respectively.

CONCLUSIONS

We detected a significantly longer survival in AE of patients with non-IPF compared with that of AE-IPFs. The prognosis of patients was affected by the underlying lung disease since pulmonary fibrosis was the underlying cause of death in the majority of all patients with FILD having experienced an AE.

Mortality and mesothelioma incidence among chrysotile asbestos miners in Balangero, Italy: A cohort study

BACKGROUND

We studied cancer mortality and mesothelioma incidence in 974 male workers employed at least 6 months at the Balangero mine (Italy), the largest chrysotile mine in Western Europe, active from 1917 to 1985.

METHODS

Vital status as of 31 May 2013, causes of deaths and mesothelioma incidence from 1990 were ascertained. Past exposure to asbestos by working area and calendar period was estimated, based on historical data of fibers concentrations. Individual cumulative exposure was assessed by applying estimates to the job history of cohort members. Standardized mortality ratios (SMRs) for selected causes and standardized incidence ratios for malignant mesothelioma (MM) were calculated based on regional reference rates. Poisson regression analysis was used to study MM and lung cancer risk by latency, duration, and cumulative exposure.

RESULTS

Mortality was increased for all causes (SMR = 1.28; 95% confidence interval [CI] = 1.17-1.40), pleural cancer (SMR = 4.30; 95% CI = 1.58-9.37), asbestosis (SMR = 375.06; 95% CI = 262.68-519.23). An increase was also found for lung cancer (SMR = 1.14; 95% CI =  0.81-1.55) and peritoneal cancer (SMR = 3.25; 95% CI = 0.39-11.75). The risk of both pleural and peritoneal cancer mortality and of mesothelioma incidence increased with increasing cumulative exposure, duration, and latency. Poisson regression analyses showed an increase in mesothelioma risk with cumulative asbestos exposure and suggest a similar trend for lung cancer. Asbestosis mortality also increased with cumulative exposure.

CONCLUSIONS

Among Balangero chrysotile miners and millers, the occurrence of malignant and nonmalignant asbestos-related diseases was increased by exposure, with dose-response relation. The study confirms the carcinogenicity of chrysotile asbestos, in particular for pleural mesothelioma.

NLRP3 and CARD8 polymorphisms influence risk for asbestos-related diseases

Background

This study aimed to investigate the association between NLRP3 rs35829419 and CARD8 rs2043211 polymorphisms and the risk of developing pleural plaques, asbestosis, and malignant mesothelioma (MM), and to study the influence of the interactions between polymorphisms and asbestos exposure on the risk of developing these diseases.

Methods

The case-control study included 416 subjects with pleural plaques, 160 patients with asbestosis, 154 subjects with MM and 149 subjects with no asbestos disease. The NLRP3 rs35829419 and CARD8 rs2043211 polymorphisms were determined using real-time PCR-based methods. In the statistical analysis, standard descriptive statistics was followed by univariate and multivariate logistic regression modelling.

Results

Asbestos exposure (medium and high vs low) was associated with the risk for each studied asbestos-related disease. An increased risk of pleural plaques was found for CARD8 rs2043211 at + TT genotypes (OR = 1.48, 95% CI 1.01-2.16, p = 0.042). When the analysis was performed for MM patients as cases, and pleural plaques patients as controls, a decreased MM risk was observed for carriers of CARD8 rs2043211 TT genotype (OR = 0.52, 95% CI 0.27-1.00, p = 0.049). The interactions between NLRP3 rs35829419 and CARD8 rs2043211 genotypes did not influence the risk of any asbestos-related disease. However, when testing interactions with asbestos exposure, a decreased risk of asbestosis was found for NLRP3 CA+AA genotypes (OR = 0.09, 95% CI 0.01-0.60, p = 0.014).

Conclusions

The results of our study suggest that NLRP3 and CARD8 polymorphisms could affect the risk of asbestos-related diseases.

Follow-Up of the Libby, Montana Screening Cohort: A 17-Year Mortality Study

OBJECTIVE

To evaluate mortality patterns among participants in a community-based screening program for asbestos-related disease.

METHODS

We calculated standardized mortality ratios (SMRs) and stratified results by exposure group (three occupational exposure groups, household contacts and residents without occupational asbestos exposure) and by radiographic abnormality presence.

RESULTS

All-cause mortality (15.8%; 1,429/8,043) was statistically lower than expected. Asbestosis was statistically elevated in all exposure groups. Lung cancer was moderately associated with vermiculite miner/miller employment. Mesothelioma was elevated in that same exposure group and among residents. Systemic autoimmune disease mortality was also elevated. Radiographic parenchymal abnormalities were associated with lung cancer mortality.

CONCLUSION

In addition to asbestos-related mortality in occupational exposure groups, this initial follow-up of this cohort also shows elevated mortality for some asbestos-related causes in non-occupational exposure groups.

Imaging and imagination in the diagnostics of asbestosis

Two cases of asbestosis diagnosed on the basis of anamnestic, clinical, and instrumental criteria, were not confirmed by forensic autopsy ordered by the public prosecutor to ascertain the cause of death. The two cases demonstrate that a suggestive working history can be misleading, in the absence of clear radiological signs and histopathological findings, and that asbestosis must be diagnosed following the criteria consolidated in the scientific literature, as any diagnostic errors can have serious legal consequences.

Asbestos, Smoking and Lung Cancer: An Update

This review updates the scientific literature concerning asbestos and lung cancer, emphasizing cumulative exposure and synergism between asbestos exposure and tobacco smoke, and proposes an evidence-based and equitable approach to compensation for asbestos-related lung cancer cases. This update is based on several earlier reviews written by the second and third authors on asbestos and lung cancer since 1995. We reevaluated the peer-reviewed epidemiologic studies. In addition, selected in vivo and in vitro animal studies and molecular and cellular studies in humans were included. We conclude that the mechanism of lung cancer causation induced by the interdependent coaction of asbestos fibers and tobacco smoke at a biological level is a multistage stochastic process with both agents acting conjointly at all times. The new knowledge gained through this review provides the evidence for synergism between asbestos exposure and tobacco smoke in lung cancer causation at a biological level. The evaluated statistical data conform best to a multiplicative model for the interaction effects of asbestos and smoking on the lung cancer risk, with no requirement for asbestosis. Any asbestos exposure, even in a heavy smoker, contributes to causation. Based on this information, we propose criteria for the attribution of lung cancer to asbestos in smokers and non-smokers.

[The occurrence of asbestos-related diseases among former employees of asbestos processing plants in Poland]

BACKGROUND

Despite the fact that asbestos is no longer used in production in Poland, there are still new cases of asbestos-related diseases among workers previously exposed to asbestos dust. This situation is related to the specificity of the biological activity of this mineral; the health consequences of asbestos can manifest not only during the exposure but also many years after exposure cessation. The aim of the analysis was to assess the occurrence of occupational diseases among people exposed to asbestos dust, who were examined under the Amiantus program.

MATERIAL AND METHODS

The research material consisted of the program cards filled by the doctors conducting the examinations as well as radiological images stored on the International Labour Organization form. The analysis covered 8049 people, including 37% of women surveyed in the years 2000-2017.

RESULTS

In the group of former employees of asbestos processing plants, the occupational disease was diagnosed in 1993 people (25%), including 584 women (19%). The most common was asbestosis (76% of occupational diseases) and pleural disease (17%). Malignant neoplasms accounted for 7% of all cases in this group. The analysis showed an increase in the incidence of respiratory system diseases along with the age of the surveyed persons, their seniority at asbestos processing plants and an increase in cumulative exposure. The chest radiographs revealed radiological changes among 75% of the examined cases, whereas the changes entitling to diagnose asbestosis, according to the criteria applicable in Poland, occurred in 23% of the workers. The adoption of international criteria would increase the incidence of asbestosis as an occupational disease by 19% in the study group.

CONCLUSIONS

The increase in the percentage of people with a diagnosed occupational disease provides evidence for the worsening health status of the former workers as well as a good detection of asbestos-related diseases among employees exposed to asbestos dust in the past. The results of the analysis indicate the need for undertaking a discussion in Poland on the implementation of international criteria for the diagnosis of asbestosis. Med Pr. 2019;70(6):723-31.

Change in prevalence of asbestos-related disease among sheet metal workers 1986 to 2016

BACKGROUND

A medical screening program began in 1986 for sheet metal workers exposed to asbestos, primarily while working alongside insulators applying spray-on asbestos materials, a practice banned in 1973. Exposure continues during maintenance, renovation, and repair.

METHODS

Radiographic abnormalities among 26 397 sheet metal workers examined from 1986 to 2016 were analyzed by year of entry into the trade. Logistic regression was used to examine risk factors for parenchymal and pleural abnormalities among the overall study population and among the subcohort who entered the trade after 1973.

RESULTS

Prevalence of parenchymal disease was 17.4% for those starting work before 1950 compared with 0.8% for those starting work after 1973 (adjusted prevalence odds ratio [pOR] = 26.65, 95% confidence interval [CI] = 18.46-38.46). For each calendar year after 1973, entering the trade 1 year later was associated with an estimated 12.7% decreased odds of acquiring asbestos-related disease (adjusted pOR = 0.873, 95% CI = 0.832-0.916).

CONCLUSION

Sheet metal workers who began work after the US implemented environmental and occupational regulations develop asbestos-related disease at much reduced rates, consistent with regulatory projections made for nonmalignant asbestos-related disease by the Occupational Safety and Health Administration at the time. Cancer remains a concern among this cohort, and lung cancer screening recommendations should consider year of entry into the trade. This study highlights the importance of regulatory intervention and of continued surveillance.

Transbronchial lung cryobiopsy: a novel confirmatory tool to diagnose asbestos-related pulmonary fibrosis

Asbestosis is diagnosed with a combination of historical, clinical and radiological findings in the absence of another cause. Histology is required when uncertainty exists, with lung biopsy via VATs being gold standard. Transbronchial cryobiopsy is becoming increasingly popular for diagnosing interstitial lung disease and may provide sufficient lung sample to demonstrate asbestosis. A 73 year old man presented with dyspnoea on a background of rheumatoid arthritis, previous methotrexate use and asbestos exposure. Examination revealed fine crackles in the mid and lower zones bilaterally without signs of pulmonary hypertension. The presence of pleural plaques and basal interstitial reticulation on HRCT was suggestive of asbestosis but histology was required to differentiate this from rheumatoid or methotrexate associated ILD. Samples of lung tissue were obtained via transbronchial cryobiopsy, demonstrating fibrosis and asbestos fibres consistent with asbestosis. Transbronchial cryobiopsy appears effective in obtaining sufficient parenchymal lung samples to diagnose asbestosis when clinical uncertainty exists.

Outcomes after lung transplantation for patients with occupational lung diseases

Occupational lung diseases (OLD) including silicosis, asbestosis, and pneumoconiosis progress to end stage lung disease requiring lung transplantation (LT). Prognosis and treatment of OLDs are poorly understood and a paucity of data exists regarding LT outcomes. Additionally, transplant operative complexity for patients with OLD is high. A single center retrospective review of all single and bilateral LT recipients between May 2005 and Oct 2016 was performed. Patients were grouped by OLD, and nearest neighbor matching was performed at a ratio of 1:3 cases to controls. Thirty cases were matched to 88 controls. Seventeen patients (57%) with OLD required intraoperative support with either extra-corporeal membrane oxygenation (ECMO) or cardiopulmonary bypass (P = 0.02), and 5 (17%) required delayed chest closure (P = 0.05) which was more frequent than matched controls. In addition, operative time was significantly longer in patients with OLD (P = 0.03). Despite these factors, there were no significant differences in immediate post-operative outcomes including mechanical ventilator support, post-operative ECMO, and tracheostomy. Chronic lung allograft dysfunction and long-term survival were also similar between cases and controls. OLDs should not preclude LT. The operation should be performed at experienced centers.

Clinical study of asbestos-related lung cancer diagnosed by asbestos medical examination

AIM

People with occupational exposure to asbestos demonstrate a high incidence of lung cancer. Asbestos medical examination for those at risk was implemented as a national policy in Japan. This study aimed to characterize patients with asbestos-related lung cancer who were diagnosed by these examinations.

METHODS

We retrospectively investigated 120 individuals exposed to asbestos who were examined from 2008 to 2016 at our institution. Clinical data, including CT findings and time-related exposure variables, were evaluated. Each asbestos-related change was assigned 1 point if present, and the scores were compared between patients with and without asbestos-related lung cancer using the Mann-Whitney U test and Fisher's exact test.

RESULTS

Five patients were diagnosed with lung cancer, and four underwent surgical treatment. At the time of writing, three of four operated patients were alive without recurrence, with a similar prognosis to patients with lung cancer unrelated to asbestos. Average scores for asbestos-related findings on CT Scan were 1.8 (9/5) for patients with lung cancer and 0.79 (91/115) for those without lung cancer.

CONCLUSION

Patients with lung cancer had significantly more asbestos-related changes on CT scan than those without lung cancer. Concurrent calcified plaque and interstitial changes might be a predictor of lung cancer incidence. Although further investigation with a larger study group is needed, regular medical examination and CT scan every 6 months might contribute to the early detection of lung cancer with asbestos-related changes on CT.

Review on the adverse health effects of asbestiform antigorite, a non-regulated asbestiform serpentine mineral

BACKGROUND

Although antigorite is generally described as platy, its fibrous (asbestiform) variant is present widespread in serpentinite rocks. In addition to its primarily fibrous occurrence, asbestiform antigorite may also be formed from serpentinite with massive appearance during tunneling and mining. It is not of commercial interest, but exposure may occur in the certain environments.

METHODS AND RESULTS

Detailed studies of the structural features of this antigorite type revealed characteristics closely related to those of chrysotile. Therefore, it is plausible that this serpentine mineral may present a similar health risk for exposed subjects. This is in agreement with results from clinical and animal studies, as well as in vitro experiments showing the cytotoxic, fibrogenic, and carcinogenic potential of antigorite, similar to that of chrysotile and amphibole asbestos.

CONCLUSIONS

Current evidence supports a need for an update to existing regulations to include unregulated asbestiform antigorite, similar to regulatory measures taken for asbestos.

Australia's Ongoing Legacy of Asbestos: Significant Challenges Remain Even after the Complete Banning of Asbestos Almost Fifteen Years Ago

The most effective way of reducing the global burden of asbestos-related diseases is through the implementation of asbestos bans and minimising occupational and non-occupational exposure to respirable asbestos fibres. Australia’s asbestos consumption peaked in the 1970s with Australia widely thought to have had among the highest per-capita asbestos consumption level of any country. Australia’s discontinuation of all forms of asbestos and asbestos-containing products and materials did not occur at a single point of time. Crocidolite consumption ceased in the late 1960s, followed by amosite consumption stopping in the mid 1980s. Despite significant government reports being published in 1990 and 1999, it was not until the end of 2003 that a complete ban on all forms of asbestos (crocidolite, amosite, and chrysotile) was introduced in Australia. The sustained efforts of trade unions and non-governmental organisations were essential in forcing the Australian government to finally implement the 2003 asbestos ban. Trade unions and non-government organisations continue to play a key role today in monitoring the government’s response to Australian asbestos-related disease epidemic. There are significant challenges that remain in Australia, despite a complete asbestos ban being implemented almost fifteen years ago. The Australian epidemic of asbestos-related disease has only now reached its peak. A total of 16,679 people were newly diagnosed with malignant mesothelioma between 1982 and 2016, with 84% of cases occurring in men. There has been a stabilisation of the age-standardised malignant mesothelioma incidence rate in the last 10 years. In 2016, the incidence rate per 100,000 was 2.5 using the Australian standard population and 1.3 using the Segi world standard population. Despite Australia’s complete asbestos ban being in place since 2003, public health efforts must continue to focus on preventing the devastating effects of avoidable asbestos-related diseases, including occupational and non-occupational groups who are potentially at risk from exposure to respirable asbestos fibres.

Asbestos-Related Disorders in Germany: Background, Politics, Incidence, Diagnostics and Compensation

There was some limited use of asbestos at end of the 19th century in industrialized countries including Germany, but its consumption dramatically increased after World War II. The increase in use and exposure was followed by the discovery of high numbers of asbestos-related diseases with a mean latency period of about 38 years in Germany. The strong socio-political pressure from the asbestos industry, its affiliated scientists and physicians has successfully hindered regulatory measures and an asbestos ban for many years; a restrictive stance that is still being unravelled in compensation litigation. This national experience is compared with the situation in other industrialized countries and against the backdrop of the constant efforts of the WHO to eliminate asbestos-related diseases worldwide.

Association between increased small airway obstruction and asbestos exposure in patients with asbestosis

BACKGROUND

Asbestos exposure may cause asbestos-related lung diseases including asbestosis, pleural abnormalities and malignancies. The role of asbestos exposure in the development of small airway obstruction remains controversial. Anatomic and physiologic small airway abnormalities may develop as part of the pathophysiologic process of asbestosis. We hypothesized that inhalation of asbestos may induce small airway defects in addition to asbestosis and pleural abnormalities.

METHODS

In total, 281 patients with newly diagnosed asbestosis were evaluated. Clinical data were collected from the patients' medical charts. The patients were classified into various stages according to their chest X-ray findings using the International Labour Organization classification. Pulmonary function was evaluated by plethysmography and the forced oscillation technique.

RESULTS

Expiratory flow, including the predicted values of the maximum expiratory flow between 25% and 50% of the forced vital capacity (MEF_25-50 ), was significantly lower in the different stages of asbestosis. Accordingly, the predicted percentage of R₅ -R₂₀ was significantly higher with increasing stages of asbestosis. Furthermore, the duration of exposure to asbestos was significantly associated with the forced expiratory volume in the first second (FEV₁ )/forced vital capacity (FVC) ratio and the predicted percentage of MEF₂₅ or MEF₅₀ according to the regression analysis in non-smoking patients with asbestosis. The predicted percentage of FEV₁ or the FEV₁ /FVC ratio was significantly lower and the predicted percentage of R₅ -R₂₀ was significantly higher in smokers than non-smokers.

CONCLUSIONS

The patients with asbestosis have small airway obstructive defects that are significantly associated with asbestos exposure.

The Tale of Asbestos in Sweden 1972-1986-The Pathway to a Near-Total Ban

This paper provides a narrative of the national intervention strategy in Sweden aimed to restrict the industrial use of asbestos. For many years, asbestos was imported for widespread industrial use, resulting in large amounts throughout Swedish society. In 1972, the whistle was blown in a Communist Party parliamentary motion describing asbestos as a health hazard and requesting action to prohibit its use. Although the motion was rejected, it initiated the extensive charting of asbestos sources on a tripartite basis, involving government agencies, and employer and trade-union organizations. Restrictive asbestos management practices were enforced from July 1982. The year 1985 saw the Government Asbestos Commission review, covering use-determining factors, international regulations, and assessments of cancer risks. The relative risks of chrysotile and amphibole were considered internationally (by the IARC), since chrysotile (a Canadian export) was regarded as unharmful in Canada at that time. Prohibiting asbestos use resulted in its virtual disappearance as an import to Sweden from the early 1980s. However, asbestos has undergone a transition from an occupational to a public-health hazard (although some work-related hazards, such as handling and disposal, remain). The transition reflects the public’s exposure to existing stocks, in homes, workplaces, etc. Mesothelioma incidence has come to be regarded as an indicator of prevention effectiveness.

Exploring Animal Models That Resemble Idiopathic Pulmonary Fibrosis

Large multicenter clinical trials have led to two recently approved drugs for patients with idiopathic pulmonary fibrosis (IPF); yet, both of these therapies only slow disease progression and do not provide a definitive cure. Traditionally, preclinical trials have utilized mouse models of bleomycin (BLM)-induced pulmonary fibrosis—though several limitations prevent direct translation to human IPF. Spontaneous pulmonary fibrosis occurs in other animal species, including dogs, horses, donkeys, and cats. While the fibrotic lungs of these animals share many characteristics with lungs of patients with IPF, current veterinary classifications of fibrotic lung disease are not entirely equivalent. Additional studies that profile these examples of spontaneous fibroses in animals for similarities to human IPF should prove useful for both human and animal investigators. In the meantime, studies of BLM-induced fibrosis in aged male mice remain the most clinically relevant model for preclinical study for human IPF. Addressing issues such as time course of treatment, animal size and characteristics, clinically irrelevant treatment endpoints, and reproducibility of therapeutic outcomes will improve the current status of preclinical studies. Elucidating the mechanisms responsible for the development of fibrosis and disrepair associated with aging through a collaborative approach between researchers will promote the development of models that more accurately represent the realm of interstitial lung diseases in humans.

[Analysis of changes in radiographic lung image and lung ventilation disorders in workers occupationally exposed to chrysotile in the past]

BACKGROUND

The adverse health effects of occupational exposure to asbestos dust may occur several years after first exposure. The objective of the study was to assess the relationship between lesions in the respiratory system and the factors contributing to occupational exposure to asbestos described in the first medical examination as well as to analyze the factors responsible for the progression of these changes in further medical tests.

MATERIAL AND METHODS

The study group comprised 591 former workers of asbestos processing plant "Gambit" in Lubawka. The results of medical examinations carried out in 2001-2012 were assessed. Statistical inference was performed based on bilateral significance tests at the 0.05 level of significance.

RESULTS

A higher risk of interstitial lung changes along with an increase in the cumulative concentration of asbestos was indicated; for the employees with the highest exposure, the adjusted odds ratio (OR) was 1.63 (95% confidence interval (CI): 0.99-2.71), while for changes with the severity degree qualifying for asbestosis diagnosis, the risk was significantly increased, over fivefold higher, compared to subjects employed in the lowest exposure. The analysis of the relationship between the progression of interstitial changes and the exposure to asbestos dust showed a fourfold higher risk of the progression in workers employed in the highest exposure. Mean values of FEV1 (forced expiratory volume in 1 s), FVC (forced vital capacity), FEV1/FVC (forced expiratory volume in 1 s to forced vital capacity) were significantly lower in the subjects working in a higher asbestos exposure. The effect of tobacco smoking on the occurrence of interstitial lung changes and their progression was also confirmed.

CONCLUSIONS

The results of prophylactic medical examinations of the health status of workers formerly employed in the plants using chrysotile indicate the importance andthe need for a long-term clinical follow-up and the promotion of anti-smoking prevention in this group of former employees. Med Pr 2017;68(2):247-258.

Mortality from asbestos-associated disease in Libby, Montana 1979-2011

Research on asbestos exposure in Libby, MT, has focused on occupational exposure in vermiculite mining and processing, but less attention has been paid to asbestos-related mortality among community members without vermiculite mining occupational history. Our study reports on asbestos-related mortality in Libby over 33 years (1979-2011) while controlling for occupational exposure. We calculated sex-specific 33-year standardized mortality ratios (SMRs) for Libby residents who died from 1979 to 2011 with an asbestos-related cause of death. Decedent address at time of death was geocoded to confirm inclusion in the Libby County Division. We controlled for past W.R. Grace employment by including and then removing them from the SMR analysis. Six hundred and ninety-four decedents were identified as having at least one asbestos-related cause of death and residing in our study area boundary. Statistically significant (P<0.05) 33-year SMRs, both before and after controlling for W.R. Grace employment, were found for: male and female non-malignant respiratory diseases, female COPD, and asbestosis for both sexes combined. Eighty-five men and two women were matched to employment records. We observed elevated asbestos-related mortality rates among males and females. SMR results for asbestosis were high for both sexes, even after controlling for past W.R. Grace employment. These results suggest that the general population may be experiencing asbestos-related effects, not just former vermiculite workers. Additional research is needed to determine whether SMRs remain elevated after controlling for secondary exposure, such as living with vermiculite workers.

Medical costs of asbestos-related diseases in Spain between 2004 and 2011

The objective of this article was to estimate the medical costs derived from malignant ARD treatment in the Spanish National Health System (NHS) between 2004 and 2011. Estimation of direct healthcare costs was based on national primary data on the cost of specialized care for inpatients and outpatients treated at NHS hospitals and on national and regional secondary data on costs of primary healthcare and pharmaceutical prescriptions. A prevalence approach was used to estimate the overall burden of ARDs. Direct medical costs of 37,557 ARDs attended in Spanish NHS facilities in 2004-2011 were estimated at 464 million euros; specialist care accounted for 50.9% of total costs, primary healthcare 10.15%, and drug prescription 38.9%. The cost was 27.8-fold higher in males than in females. Bronchopulmonary cancers represented the greatest healthcare cost, 281 million euros. The cost of delivering healthcare to ARDs victims in Spain has a negative economic impact on the NHS due to the gross under-recognition of occupational victims under the Spanish National Insurance System.

Isoprostanes - A novel major group of oxidative stress markers

Isoprostanes are a recently discovered group of prostaglandin isomers. Results of previous studies suggest that they can be used as oxidative stress markers, because in a number of cardiovascular, pulmonary and neurological diseases their levels in biological samples considerably increase. It has been found that people suffering from diabetes, obesity, homozygous familial hypercholesterolemia, moderate hypercholesterolemia, and smokers have higher levels of isoprostanes in urine. The same refers to patients with asthma, Alzheimer disease and Down syndrome. This paper reviews the results of relevant studies.

Clarence Borel

Borel v. Fibreboard Paper Products Corporation is the 1973 landmark case that paved the way for successful litigation against the asbestos industry. Clarence Borel's granddaughter shares recollections of the reluctant man behind the court case.

Working with asbestos and the possible health risks

BACKGROUND

The generic term asbestos refers to a group of crystalline mineral silicates that occur naturally in various forms. Because of their properties of strength, heat and electrical resistance and their ability to withstand corrosion by acids and sea water, asbestos was used extensively both in the UK and worldwide.

AIMS

To provide a historical perspective of this ubiquitous occupational hazard, consider the key changes in UK legislation aimed at improving the management of this occupational health risk and describe the evidence from the scientific literature concerning asbestos and disease.

METHODS

Original articles, reviews (including reference textbooks) and scientific literature in PubMed and other principal medical science databases, 1960-2014, were searched. Publications by regulatory agencies and by governmental organizations were also considered and included where relevant.

RESULTS

Asbestos remains the biggest cause of cancer deaths worldwide. For malignant mesothelioma deaths alone, it is estimated that in the UK, between 2015 and 2020, the number of cases will peak at 2500 cases annually. It is not clear whether there is a safe level of asbestos fibres in air. Evidence for the efficacy of health surveillance is lacking.

CONCLUSIONS

Although the use of asbestos was banned in the UK in 1985 (amosite and crocidolite) and 1999 (chrysotile), it remains a significant occupational risk factor for work-related morbidity and mortality, causing both benign and malignant diseases, often with long latency. Further research is needed regarding exposure levels and health surveillance.

Exposure-response estimate for lung cancer and asbestosis in a predominantly chrysotile-exposed Chinese factory cohort

BACKGROUND

Cumulative fiber exposures, predominantly chrysotile, were estimated in a Chinese asbestos worker cohort and exposure-response relationships with lung cancer mortality and cumulative incidence of asbestosis were determined.

METHODS

Individual time-dependent cumulative exposures were estimated for 577 asbestos workers, followed prospectively for 37 years. Occupational history and smoking data were obtained from company records and personal interviews; vital status and causes of death were ascertained from death registries and hospital records. Hazard ratios were generated for disease outcomes, with adjustments for smoking and age.

RESULTS

Median cumulative fiber exposure for the cohort was 132.6 fiber-years/ml (IQR 89.3-548.4). Exposure-response relationships were demonstrated for both disease outcomes, with nearly sixfold and threefold increased risks seen at the highest exposure level for lung cancer deaths and asbestosis, respectively.

CONCLUSION

Evidence using quantitative exposure estimates was provided for increased risks of lung cancer mortality and development of asbestosis in a predominantly chrysotile-exposed cohort.

Usual interstitial pneumonia in asbestos-exposed cohorts - concurrent idiopathic pulmonary fibrosis or atypical asbestosis?

AIMS

To determine whether usual interstitial pneumonia (UIP) pattern fibrosis is seen in asbestosis.

METHODS AND RESULTS

The occurrence of UIP pattern fibrosis was studied in four asbestos cohorts systematically referred following postmortem to the UK Pneumoconiosis Unit, Cardiff. The combined exposed workforce comprised >25 000 persons. Over the 17-year period, 233 subjects were identified; 210 had degrees of interstitial fibrosis with a fibrotic non-specific interstitial pneumonia pattern and subpleural accentuation, and three showed UIP pattern fibrosis. All three of these cases showed grade 4 fibrosis (honeycombing) with no asbestos fibre dose-response correlation. A Poisson distribution of probability analysis indicated that the observed cases of UIP in this workforce could be wholly accounted for by the prevalence of idiopathic pulmonary fibrosis (IPF) in the population.

CONCLUSIONS

UIP pattern fibrosis is rarely observed in asbestos-exposed subjects, and shows no dose-response correlation with asbestos fibres on mineral analysis; this points to an alternative disease, such as IPF. The results indicate that UIP pattern fibrosis should not be regarded as genuine asbestosis, irrespective of the status of asbestos biomarkers, and this impacts upon the postmortem handling of asbestos-related deaths.

The comparison of high-resolution computed tomography findings in asbestosis and idiopathic pulmonary fibrosis

BACKGROUND

To determine whether the HRCT findings are useful to differentiate asbestosis from idiopathic pulmonary fibrosis (IPF).

METHODS

We assessed HRCT scans from patients with asbestosis (n = 96) and IPF (n = 65). The frequencies and extent of parenchymal abnormalities and the frequencies of pleural changes were evaluated by consensus of two chest radiologists.

RESULTS

There was a significant difference between IPF and asbestosis in pleural changes. In addition, there were significant differences between IPF and asbestosis in several parenchymal abnormalities on CT, especially in the less advanced stage of both diseases. On multivariate analysis, HRCT features that distinguished asbestosis from IPF were subpleural lines at a distance of less than 5 mm from the inner chest wall, subpleural dots and parenchymal bands.

CONCLUSIONS

There are significant differences between IPF and asbestosis in the parenchymal and pleural abnormalities on CT.

Commentary on pathologic diagnosis of asbestosis and critique of the 2010 Asbestosis Committee of the College of American Pathologists (CAP) and Pulmonary Pathology Society's (PPS) update on the diagnostic criteria for pathologic asbestosis

We reviewed the 2010 Asbestosis Committee's update on the diagnostic criteria for pathologic asbestosis. We must respectfully disagree with many of the criteria set forth therein, especially for recognizing asbestosis at its earliest stages; with statements focusing on the number of asbestos bodies needed in order to make a pathologic diagnosis of asbestosis; and regarding the benefits and pitfalls of relying on fiber analysis for diagnostic purposes, especially where chrysotile asbestos is concerned, including the methodology used for fiber determination. This critique has become even more relevant with the 2014 Helsinki criteria publication, which adopted the 2010 CAP/PPS criteria. Based on our review of these newer criteria and our experience in this field, we find that the CAP-NIOSH 1982 criteria is still the most acceptable method for the pathologic diagnosis and grading of asbestosis, which can be described as pulmonary fibrosis caused by inhalation of asbestos fibers.