Relationships between asbestos exposure and pleural plaques: dose and time effects using fractional polynomials.

OBJECTIVE: The aim of this study was to confirm the relationship between several parameters of exposure to asbestos and pleural plaques (PP) using data from a large cohort of retired workers occupationally exposed to asbestos in France. METHOD: A large screening programme, including high-resolution CT (HRCT) examinations at inclusion and two other HRCT campaigns, was organised from 2003 to 2016 in four regions of France for voluntary, formerly asbestos-exposed workers. Exposure to asbestos has been evaluated by industrial hygienists based on the complete work history. The time since first exposure, the time since last exposure, Cumulative Exposure Index and maximum level of exposure to asbestos, were used in logistic regression using fractional polynomials to model the relationship with PP. RESULTS: The study included 5392 subjects with at least one HRCT available. There was a significant non-linear effect of time since first exposure, time since last exposure and Cumulative Exposure Index to asbestos on the presence of PP. The risk of PP increased with increasing Cumulative Exposure Index to asbestos adjusted for time since first exposure, age and smoking status. Models also show that PP odds rise with increasing time since first exposure adjusted for cumulative index exposure, age and smoking status. PP odds decrease when time since last exposure increases. CONCLUSION: The study provides new data on the link between asbestos exposure and the presence of PP using fractional polynomials with non-linear relationships for time exposure parameters and asbestos exposure parameters.

Decade-long insights: tracking asbestos-related health impacts among formerly exposed workers in Palermo, Italy.

Background: Asbestos is a foremost occupational carcinogen globally. Despite the prohibition under Law 257/1992, Italy persists as one of the European nations most burdened by asbestos-related diseases (ARDs). This research assessed ARD cases in asbestos-exposed workers from the Province of Palermo, Italy, spanning 2010-2021. Methods: Data acquisition utilized the epidemiological dataset from the 'Service of Prevention and Safety on Work Environment' under the Prevention Department of Palermo's Local Health Authority (LHA). Results: Between 2010 and 2021, we identified 245 ARD instances, comprising 163 Asbestosis/Pleural plaques, 41 Lung Cancers, 38 Mesotheliomas, and 3 unspecified cases. Multivariate analysis indicated a notable decline in temporal exposure for mesothelioma (HR=0.933; 95% CI=0.902-0.965) and lung cancer (HR=0.93; 95% CI=0.90-0.978) relative to pleural plaques/asbestosis. Tobacco use displayed a pronounced correlation with lung cancer (smoker HR=64.520 95% CI=13,075-318.390; former smoker HR=20.917 95% CI=4,913-89.048). A significant link was observed between mesothelioma and pleural plaques/asbestosis in those employed in shipbuilding and repair (HR=0.371 95% CI=0.155-0.892). Conclusions: ARDs persist in clinical observations, even following the 1992 cessation of asbestos-related activities, emphasizing an enduring public health challenge. Enhancing prevention strategies is paramount, focusing on amplifying anamnestic and occupational data collection, thereby facilitating superior early diagnosis strategies for these maladies in the occupationally exposed cohort.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Migration and work in postwar Australia: mortality profile comparisons between Australian and Italian workers exposed to blue asbestos at Wittenoom.

OBJECTIVES: Three hundred and thirty thousand Italians arrived in Australia between 1945 and 1966, many on assisted passage schemes where the worker agreed to a 2-year unskilled employment contract. Italians were the largest of 52 migrant groups employed at the Wittenoom blue asbestos mining and milling operation. We compare mortality from asbestos-related diseases among Italian and Australian workers employed at Wittenoom. METHODS: A cohort of 6500 male workers was established from employment records and followed up at state and national mortality and cancer registries. SMRs were calculated to compare mortality with the Western Australian male population. Time-varying Cox proportional hazards models compared the risk of mesothelioma between Australian and Italian workers. RESULTS: 1031 Italians and 3465 Australians worked at Wittenoom between 1943 and 1966. Duration of employment was longer for the Italian workers, although the concentration of exposure was similar. The mesothelioma mortality rate per 100 000 was higher in Italians (184, 95% CI 148 to 229) than Australians (128, 95% CI 111 to 149). The risk of mesothelioma was greater than twofold (HR 2.27, 95% CI 1.43 to 3.60) in Italians at the lowest asbestos exposure category (<10 fibre years/per mL). CONCLUSIONS: A hierarchy in migration, isolation and a shortage of workers led to Italians at Wittenoom incurring higher cumulative exposure to blue asbestos and subsequently a greater rate of malignant mesothelioma than Australian workers. IMPACT: Poor working conditions and disparities between native and foreign-born workers has had a detrimental and differential impact on the long-term health of the workforce.

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.

[Health impact of asbestos fibres naturally occurring in Mount Pollino area (Basilicata Region, Southern Italy)]. / Impatto sulla salute delle fibre di amianto presenti in affioramenti naturali nell'area del Pollino (Basilicata).

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

Biological Monitoring of Inhaled Nanoparticles in Patients: An Appealing Approach To Study Causal Link between Human Respiratory Pathology and Exposure to Nanoparticles.

Although necessary, in vitro and in vivo studies are not fully successful at predicting nanomaterials toxicity. We propose to associate such assays to the biological monitoring of nanoparticles in clinical samples to get more relevant data on the chemical and physical nature and dose of nanoparticles found in humans. The concept is to establish the load of nanoparticles in biological samples of patients. Then, by comparing samples from different patient groups, nanoparticles of interest could be identified and a potential link between a given nanoparticle type and toxicity could be suggested. It must be confirmed by investigating the biological effects induced by these nanoparticles using in vitro or in vivo models (mechanistic or dose-response studies). This translational approach from the bedside to the bench and vice versa could allow a better understanding of the nanoparticle effects and mechanisms of toxicity that can contribute, at least in part, to a disease.

Long-term epidemiological observation of asbestos-related diseases in Poland, 1970-2015.

BACKGROUND: Occupational exposure to asbestos constitutes a major public health concern. Despite this in many countries, data and registration systems for occupational asbestos-related diseases are non-existent or poorly developed. AIMS: To analyse the incidence of occupational asbestos-related diseases in Poland between the years 1970 and 2015, with particular emphasis on the periods after introduction of a ban on asbestos and following introduction of a surveillance programme. METHODS: Analysis based on all medically recognized cases, certified as occupational diseases and reported obligatorily from all over the country to the Central Register of Occupational Diseases. RESULTS: During the period 1970-2015, 4983 cases were reported as asbestos-related diseases. The most prevalent were asbestosis, lung cancer, diseases of pleura or pericardium and mesothelioma. A considerable increase in the number of such cases from the beginning of their registration until 2004 occurred after introduction of the Amiantus programme, a nationwide programme of periodic medical examinations for former asbestos workers. CONCLUSIONS: Introduction of a medical surveillance programme improved case recognition and allowed a more reliable estimate of the number of reported asbestos-related diseases.

Asbestos exposure increases the incidence of histologically confirmed usual interstitial pneumonia.

AIMS: We hypothesized that asbestos exposure increases the incidence of macroscopically visible and histologically confirmed usual interstitial pneumonia (histological UIP). METHODS AND RESULTS: We retrospectively examined 1718 cases (1202 males; mean age 66.7 years) who underwent lobectomy for resection of pleuropulmonary tumours. Objective markers for asbestos exposure included: the presence of malignant pleural mesothelioma, the presence of pleural plaques (PPs) and asbestos bodies in the histological specimen. Risk factors for histological UIP were examined. Two separate groups were studied: 183 with asbestos exposure, and 239 with histological UIP. The 183 cases with asbestos exposure had higher rates of positive occupational history and histological UIP (31%) than the remaining 1535. Among the asbestos-exposed group, small numbers of asbestos bodies were found in histological specimens of 21 cases of histological UIP. PPs and asbestos bodies were more frequent in the 239 patients with histological UIP than in the remaining 1479 UIP-negative patients. Multivariate analysis showed that asbestos exposure, especially positivity for asbestos bodies, that does not meet the current criteria for asbestosis increases the risk of histological UIP (P < 0.0001). CONCLUSIONS: Asbestos exposure causes asbestosis and increases the incidence of histological UIP.

Tyler asbestos workers: A mortality update in a cohort exposed to amosite.

The Tyler asbestos plant produced pipe insulation from 1954 to 1972 and exclusively used amosite asbestos. There were 1130 former workers of this plant during the period of operation. A death certificate mortality analysis was published regarding this plant in 1998 for the period through 1993. This study represents an update of the mortality analysis with additional certificates collected for deaths occurring through 2011.Searches of the National Death Index database were conducted in 2004 and again in 2013. At the time of the latter search, only deaths occurring through 2011 were available. In total, 265 distinct additional death certificates were secured and added to 304 available from the original study. After the new certificates were coded (ICD-9), data were analyzed using the Centers for Disease Control and Prevention Life Table Analysis System (LTAS) and standard mortality ratios (SMR) generated with 95% confidence limits (CL). LTAS constructs cause-specific mortality rates by age, gender, race, and person-time at risk, and compares observed rates with a referent population in order to derive SMR. A significant excess number of deaths due to nonmalignant respiratory disease (asbestosis) and from select malignant neoplasms were identified. There were in total 23 mesothelioma deaths (4% of deaths), with 16 pleural and 7 peritoneal. The SMR for malignant neoplasms of the trachea, bronchus, and lung was 244 (with 95% CL 196, 300), suggesting that exposed workers from this cohort were nearly 2.5-fold (244 %) more likely to die from this cause as the general referent population. The analysis also showed that exposures of short duration (<6 mo) produced significantly elevated SMR for all respiratory cancers, lung cancer, and pleural mesothelioma. There was a significant difference in median duration of exposure for mesothelioma types, confirming association of peritoneal mesothelioma with longer duration of exposure. Deaths due to intestinal cancer (predominantly colon; not including rectum) were also found in excess. The mortality experience of the Tyler cohort continues to be followed with great interest, given the exclusivity of exposure to amosite. Data confirm the inherent pathogenicity of this fiber type for nonmalignant disease as well as select cancers, particularly relevant given the importance of this amphibole's use in the United States.

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.

[Not Available]. / Asbestos-related diseases and biological index of cumulative dose in shipyard workers (1996-2015).

BACKGROUND: Asbestos-related diseases among shipyard workers are well known in Italy but descriptive long-term studies are limited; asbestos has been extensively used but the past exposure intensity has never been estimated because data from environmental and biological monitoring are almost absent. OBJECTIVES: To describe the asbestos-related dis-eases (1996-2015) diagnosed among shipbuilding workers from a very important shipyard in Northern Italy, and to assess past asbestos exposure levels by cumulative dose indices, fibres and asbestos bodies. METHODS: The cases of workers suffering from asbestos-related diseases diagnosed from 1996 to 2015 were collected on the occasion of some legal trials; the diagnosis, and the asbestos occupational and non-occupational exposure, were carefully evaluated.Lung samples were obtained from subjects, taking advantage of the autopsies; asbestos fibers were counted by means of a Scanning Electron Microscope, equipped with x-ray fluorescence microanalyses at 12.0000 amplification, and asbestos bodies by means of an Optical Microscope at 500 amplification. RESULTS: 192 malignant mesotheliomas (6 in women), 196 lung cancers and 14 asbestosis (without cancer) were observed (1996-2015); autopsies were carried out on 80% of all subjects and 98% of mesotheliomas were confirmed by autopsies. Pleural plaques occurred on 90% of mesotheliomas and 87% of lung cancers; histologically mild asbestosis were diagnosed on 28% of mesotheliomas and 48% of lung cancers. In malignant mesothelioma and lung cancer cases respectively, the duration of occupational exposure was on average 24 and 23 ys, the latency time 48 and 46 ys, hiring at the shipyard before 1970 24 and 23 ys. Out of 114 lung analysis, the burden of asbestos fibres was >10 million for 33.3% of subjects and out of 99 lung analysis asbestos bodies was >10.000 for 71.7%; the average time since last exposure was 31 ys. Both asbestos fibres and asbestos bodies concentrations were significantly higher (GMR 2,5) among mesothelioma vs lung cancer. CONCLUSION: A relevant number of asbestos-related diseases among shipbuilding workers, mainly mesothelioma and lung cancer, exposed in shipyard until the 1980's were identified by an active search. Thanks to several autopsies, the diagnoses of cancer are confirmed as a cause of death, and a high frequency of histological asbestosis, previously ignored,was shown. The lung burden analysis of asbestos bodies and asbestos fibres, the largest ever performed among ship-building workers, confirms the spread and relevance of asbestos exposure. The best estimate of past exposure intensity was provided by both biological indices.

The global health dimensions of asbestos and asbestos-related diseases.

The Collegium Ramazzini (CR) reaffirms its long-standing position that responsible public health action is to ban all extraction and use of asbestos, including chrysotile. This current statement updates earlier statements by the CR with a focus on global health dimensions of asbestos and asbestos-related diseases (ARDs). The ARD epidemic will likely not peak for at least a decade in most industrialized countries and for several decades in industrializing countries. Asbestos and ARDs will continue to present challenges in the arena of occupational medicine and public health as well as in clinical research and practice, and have thus emerged as a global health issue. Industrialized countries that have already gone through the transition to an asbestos ban have learned lessons and acquired know-how and capacity that could be of great value if deployed in industrializing countries embarking on the transition. The accumulated wealth of experience and technologies in industrialized countries should thus be shared internationally through global campaigns to eliminate ARDs.