The asbestos paradox: global gaps in the translational science of disease prevention

Microscopic and radioanalytical investigation of asbestos-containing decommissioning waste

During decommissioning of nuclear facilities, possibly contaminated asbestos containing materials (ACM) emerge. In this work, we propose an analytical method to characterize ACM contaminated with alpha and beta nuclides by microscopic (light and electron microscopy) and radioanalytical techniques. For this purpose, a chromatographic separation is applied after decomposition of ACM by a lithium borate fusion at 1065 °C. The subsequent separation is performed with UTEVA-TRU-Sr chromatographic resins. Recovery rates for analyzed radionuclides were on an average of 80–90% for Am, Cm, Pu isotopes, and Sr-90. Compared to sample pre-treatment with hydrofluoric acid, the lithium borate fusion proves more suitable, while providing higher working safety.

Occurrence of asbestos-related occupational diseases in the Czech Republic in the last 20 years

OBJECTIVES

Asbestos-related diseases are still a current problem worldwide. What is their occurrence in the Czech Republic? The answer is the subject of this study, which aims to provide a general and regional overview of the situation over the last 20 years with a more detailed focus on mesothelioma, the development of which is highly associated with asbestos exposure and the issue of their recognition as an occupational disease.

METHODS

In its retrospective reviews, the study is based on analyses of data from the Institute of Health Information and Statistics of the Czech Republic and data from the Czech National Cancer Registry, which also interconnects.

RESULTS

In the last 20 years, 512 new cases of occupational diseases from asbestos have been reported, namely 228 cases of pleural thickening, 133 mesotheliomas, 92 asbestoses, and 59 cases of lung cancer. In the last 5 years, mesotheliomas (n = 39) predominated among the reported diseases with a 45% proportion in the total number of 86 cases. The trend in their incidence, as the only one among asbestos-related diseases, is not declining. There was a significant difference in the overall incidence of mesothelioma in a general population and the incidence of occupational mesotheliomas. At the national level, occupational aetiology was acknowledged in only 11.3% of cases of mesothelioma on average. The highest proportion of occupational mesotheliomas and the highest incidence of all asbestos-related diseases were found in regions where the largest asbestos processing plants were located.

CONCLUSION

The authors emphasize the importance of work history for the diagnostic process of asbestos-related diseases and also the need to perform follow-up examinations for their early detection.

Prevention of Asbestos Exposure in Latin America within a Global Public Health Perspective

Background:

Asbestos consumption in Latin America (LA) amounts to 10% of yearly global production. Little is known about the impact of asbestos exposure in the region.

Objective:

To discuss scientific and socio-economic issues and conflicts of interest and to summarize epidemiological data of asbestos health effects in LA.

Discussion:

Recent data on chrysotile strengthened the evidence of its carcinogenicity and showed an excessive risk of lung cancer at cumulative exposure levels as low as 1.5 fibre-years/ml. Technology for substitution is available for all asbestos-containing products and ceasing asbestos production and manufacturing will not result in unemployment and loss of income, except for the mining industry. The flawed arguments used by the industry to maintain its market, both to the public and in courtrooms, strongly relies on the lack of local evidence of the ill effects and on the invisibility of asbestos-related diseases in LA, due to the limited number of studies and the exposed workers’ difficulty accessing health services. The few epidemiological studies available show clear evidence of clusters of mesothelioma in municipalities with a history of asbestos consumption and a forecasted rise in its incidence in Argentina and Brazil for the next decade. In Brazil, non-governmental organizations of asbestos workers were pivotal to counterbalance misinformation and inequities, ending recently in a Supreme Court decision backing an asbestos ban. In parallel, continuous efforts should be made to stimulate the growth of competent and ethical researchers to convey adequate information to the scientific community and to the general public.

Asbestos neglect: Why asbestos exposure deserves greater policy attention

While many public health threats are now widely appreciated by the public, the risks from asbestos exposure remain poorly understood, even in high-risk groups. This article makes the case that asbestos exposure is an important, ongoing global health threat, and argues for greater policy efforts to raise awareness of this threat. It also proposes the extension of asbestos bans to developing countries and increased public subsidies for asbestos testing and abatement.

Experimental Model of Human Malignant Mesothelioma in Athymic Mice

Malignant pleural mesothelioma (MPM) is a thoracic aggressive cancer caused by asbestos exposure, which is difficult to diagnose and treat. Here, we characterized an in vivo orthotopic xenograft model consisting of human mesothelioma cells (designed as H2052/484) derived from a pleural NCI-H2052 tumor injected in partially immunodeficient athymic mice. We assessed tumor formation and tumor-dependent patterns of inflammation. H2052/484 cells conserved their mesothelioma phenotype and most characteristics from the parental NCI-H2052 cells. After intra-thoracic injection of H2052/484 cells, thoracic tumors developed in nearly all mice (86%) within 14 days, faster than from parental NCI-H2052 cells. When the mice were euthanized, the pleural lavage fluid was examined for immune cell profiles. The pleural immune cell population increased with tumor development. Interestingly, the proportion of myeloid-derived suppressor cell and macrophage (especially CD206⁺ M2 macrophages) populations increased in the pleural fluid of mice with large mesothelioma development, as previously observed in immunocompetent mice. This reliable orthotopic model recapitulates human mesothelioma and may be used for the study of new treatment strategies.

Polymeric films loaded with cisplatin for malignant pleural mesothelioma: a pharmacokinetic study in an ovine model

BACKGROUND

Malignant pleural mesothelioma (MPM) continues to be a distressing tumor due to its aggressive biologic behavior and scanty prognosis. Several therapeutic approaches have been tested both in clinical and preclinical settings, being intrapleural chemotherapy one of the most promising. Some years ago, our interest focused on polymeric films loaded with cisplatin for the adjuvant intrapleural treatment of surgical patients. After in vitro and in vivo studies in a rat recurrence model of MPM, the aim of this study was to evaluate the pharmacokinetics of the polymeric films in a sheep model in view of further studies in a clinical setting.

METHODS

An ovine model was used. Animals were divided into four groups according to pharmacologic treatment: control group (three animals undergoing left pneumonectomy and saline-NaCl solution); intrapleural hyaluronate cisplatin films (HYALCIS) group (six animals undergoing left pneumonectomy and intrapleural application of polymeric films loaded with cisplatin); intrapleural cisplatin solution (six animals undergoing left pneumonectomy and intrapleural application of cisplatin solution); intravenous cisplatin (five animals undergoing left pneumonectomy and intravenous administration of cisplatin solution). The primary objective was the plasmatic and pleural concentration of cisplatin in the treatment groups. The secondary objective was the treatment-related toxicity evaluated by plasmatic analysis performed at prearranged time intervals and histological examinations of tissue samples collected during animal autopsy. Analysis of variance (ANOVA) was used for statistical analysis. Bonferroni correction was applied for comparison between all groups.

RESULTS

Twenty female Sardinian sheep with a mean weight of 45.1 kg were studied. All animals survived the surgical procedures. The whole surgical procedure had a mean duration of 113 minutes. Cisplatin blood levels obtained from polymeric films application were low during the first 24 hours after the application; then, the cisplatin blood level increased gradually and progressively until it reached significantly higher plasmatic concentrations after 120 hours compared to intrapleural cisplatin solution (P=0.004) and intravenous administration (P=0.001), respectively. Considering cisplatin concentration at 168 hours after the application, animals treated with polymeric films had higher plasmatic values than animals treated with intrapleural cisplatin solution and intravenous cisplatin (P=0.001). Despite the high cisplatin plasmatic concentrations, treatment related-toxicity towards kidneys and liver was comparatively lower compared to the intravenous and intrapleural cisplatin administration and closer to the control levels.

CONCLUSIONS

Polymeric films loaded with cisplatin allowed to reach significantly higher intrapleural and plasmatic cisplatin concentrations compared to intrapleural and intravenous cisplatin solution, providing at the same time, a significant reduction of treatment related toxicity.

Exhaled breath to screen for malignant pleural mesothelioma: a validation study

Malignant pleural mesothelioma (MPM) is predominantly caused by asbestos exposure and has a poor prognosis. Breath contains volatile organic compounds (VOCs) and can be explored as an early detection tool. Previously, we used multicapillary column/ion mobility spectrometry (MCC/IMS) to discriminate between patients with MPM and asymptomatic high-risk persons with a high rate of accuracy. Here, we aim to validate these findings in different control groups.Breath and background samples were obtained from 52 patients with MPM, 52 healthy controls without asbestos exposure (HC), 59 asymptomatic former asbestos workers (AEx), 41 patients with benign asbestos-related diseases (ARD), 70 patients with benign non-asbestos-related lung diseases (BLD) and 56 patients with lung cancer (LC).After background correction, logistic lasso regression and receiver operating characteristic (ROC) analysis, the MPM group was discriminated from the HC, AEx, ARD, BLD and LC groups with 65%, 88%, 82%, 80% and 72% accuracy, respectively. Combining AEx and ARD patients resulted in 94% sensitivity and 96% negative predictive value (NPV). The most important VOCs selected were P1, P3, P7, P9, P21 and P26.We discriminated MPM patients from at-risk subjects with great accuracy. The high sensitivity and NPV allow breath analysis to be used as a screening tool for ruling out MPM.

Barriers and Facilitators to the Elimination of Asbestos Related Diseases-Stakeholders' Perspectives

Despite sound scientific knowledge and evidence that any exposure to asbestos fibers in all of its forms, are carcinogenic to humans, its presence, use and trade is still substantial, including in the World Health Organization (WHO) European Region. Banning the production and use of all forms of asbestos, as recommended by the International Labour Organization (ILO) and WHO, has been proven as the most efficient evidence-based strategy to eliminate Asbestos Related Diseases (ARDs). To effectively move elimination of ARDs forward, attaining a greater understanding of key stakeholders perspectives was identified as an important action. The WHO Regional Office for Europe, the European Centre for Environment and Health, undertook semi-structured interviews, and follow-up discussions with diverse representatives dealing professionally with asbestos. The interview questionnaire was developed based on the current ARDs WHO Report, the Evidence Implementation Model for Public Health and categories of the theory of diffusion. Data were attained on three main questions within the interview questionnaire: (1) Identifying barriers to implementation of WHO evidence-based asbestos recommendations; (2) Describing roles of key stakeholders; and, (3) Proposing possible solutions. The results demonstrated use of sound and convincing scientific evidence along with economic evidence and facilitators can be used to achieve evidence-based policy development, and comprehensive diverse actions.

Medical monitoring of asbestos-exposed workers: experience from Poland

In Poland, the use of asbestos was banned in 1997 and asbestos plants have been closed since then. Despite their closure, cases of asbestos-related occupational diseases among former asbestos workers are still being recorded in the Central Register of Occupational Diseases. Between 2001 and 2014, there were 2726 asbestos-related illnesses, classified and reported as diseases associated with occupational exposure to asbestos. In 2000, Poland introduced a programme called Amiantus, targeted at former asbestos-processing plant workers. The programme provided periodic medical examinations to workers and free access to medications for treatment of asbestos-related illnesses. Introduction of the programme provided additional data to generate a reliable estimation of the number of asbestos-related occupational diseases, including cancer. The average latency period for asbestosis, lung cancer and mesothelioma is about 40 years so there may still be some health impact to former workers necessitating follow-up. We present the Polish experience of implementing a medical examination programme for asbestos-exposed workers and provide a list of activities to consider when planning for such a programme.