Sailors and the Risk of Asbestos-Related Cancer

Sailors have long been known to experience high rates of injury, disease, and premature death. Many studies have shown asbestos-related diseases among shipyard workers, but few have examined the epidemiology of asbestos-related disease and death among asbestos-exposed sailors serving on ships at sea. Chrysotile and amphibole asbestos were used extensively in ship construction for insulation, joiner bulkhead systems, pipe coverings, boilers, machinery parts, bulkhead panels, and many other uses, and asbestos-containing ships are still in service. Sailors are at high risk of exposure to shipboard asbestos, because unlike shipyard workers and other occupationally exposed groups, sailors both work and live at their worksite, making asbestos standards and permissible exposure limits (PELs). based on an 8-hour workday inadequate to protect their health elevated risks of mesothelioma and other asbestos-related cancers have been observed among sailors through epidemiologic studies. We review these studies here.

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.

Validation of an Asbestos Exposure Questionnaire (QEAS-7) for Clinical Practice

Introduction: The seven-item QEAS-7 questionnaire (exposure to asbestos questionnaire) has been designed as a useful and simple tool to establish the probability of exposure to asbestos. The objective of the present study is to validate the QEAS-7 following the recommended methodology. Methods: The QEAS-7 was prospectively administered to 90 subjects with and without asbestos-related disease (ARD), on two consecutive occasions by two independent researchers. Logical and content validity was evaluated by a committee of experts and construct validity through hypothesis testing. Intra- and interobserver reliability was assessed by calculating Cohen’s Kappa index (κ), which was estimated as weak if below 0.40, moderate if between 0.41 and 0.60 and good/very good if above 0.60. The comparison between proportions was examined using Pearson’s Chi-square test. Results: The majority of participants (88.9%) were male. Mean age was 70.8 years (SD = 8.4) and most of the sample had completed primary education but had not progressed further (62.2%). Forty-three had ARD. The logical, content and construct validity of the QEAS-7 was considered adequate both by a committee of experts and by the users interviewed. The mean administration time was 9 min and 25 s (SD = 3 min and 49 s). The verification of the five hypotheses confirmed the construct validity and the intra- and interobserver reliability to be κ = 0.93 and κ = 0.50 respectively. The concordance in the estimation of asbestos exposure was κ = 0.65. Conclusions: The QEAS-7 is a simple, valid and reliable tool for estimating the probability of exposure to asbestos. Its application in clinical practice appears justified. What is already known about this subject? No studies have been published to date on the validation of specific questionnaires designed to determine asbestos exposure for routine use by healthcare staff in the clinical setting. What are the new findings? This questionnaire can be considered a comprehensible, viable, valid and reliable instrument for identifying exposure to asbestos. Its brevity and simplicity of administration make it ideally suited for use in daily clinical practice. How might this impact on policy or clinical practice in the foreseeable future? This questionnaire can be of help for physicians attending to patients with suspected asbestos-related diseases both in the hospital and in the primary care setting.

Voluntary exercise in mesothelioma: effects on tumour growth and treatment response in a murine model

Objective There is substantial evidence that exercise can safely reduce the risk of cancer and improve survival in different human cancer populations. Long latency periods associated with carcinogen–induced cancers like asbestos induced mesothelioma provide an opportunity to implement exercise as an intervention to delay or prevent disease development. However, there are limited studies investigating the ability of exercise to prevent or delay cancer, and exercise as a preventive strategy has never been assessed in models with a known carcinogen. We investigated the potential of voluntary exercise (VE) to delay development of asbestos related disease (ARD) in our well-characterised, asbestos induced MexTAg model of mesothelioma. Results Asbestos exposed MexTAg mice were given continuous or delayed access to VE and ARD assessed over time. We found that the addition of VE did not affect ARD development in asbestos exposed MexTAg mice. However, non–asbestos exposed, aged matched control mice participated in significantly more VE behaviours, suggesting subclinical development of ARD after asbestos exposure had a greater impact on VE participation than age alone. These data highlight the importance of model choice and the potential limitation that some pre–clinical studies may not accurately represent the clinical paradigm, particularly in the context of prevention studies.

Voluntary Exercise in Mesothelioma: Effects on Tumour Growth and Treatment Response in a Murine Model

Objective: There is substantial evidence that exercise can safely reduce the risk of cancer and improve survival in different human cancer populations. Long latency periods associated with carcinogen‑induced cancers like asbestos induced mesothelioma provide an opportunity to implement exercise as an intervention to delay or prevent disease development. However, there are limited studies investigating the ability of exercise to prevent or delay cancer, and exercise as a preventive strategy has never been assessed in models with a known carcinogen. We investigated the potential of voluntary exercise (VE) to delay development of asbestos related disease (ARD) in our well-characterised, asbestos induced MexTAg model of mesothelioma.Results: Asbestos exposed MexTAg mice were given continuous or delayed access to VE and ARD assessed over time. We found that the addition of VE did not affect ARD development in asbestos exposed MexTAg mice. However, non‑asbestos exposed, aged matched control mice participated in significantly more VE behaviours, suggesting subclinical development of ARD after asbestos exposure had a greater impact on VE participation than age alone. These data highlight the importance of model choice and the potential limitation that some pre‑clinical studies may not accurately represent the clinical paradigm, particularly in the context of prevention studies.

Occupational exposure for asbestos-related disease groups: geomapping of the last 5 years in Italy

Background Asbestos-related diseases are a public health challenge in Italy: the country has been a major producer and user of asbestos since World War II until complete ban in 1992. Several contaminated sites and structures across the country have never been decontaminated: incidence peak of asbestos-related diseases is expected somewhen between 2015 and 2020. Study objective is to investigate incidence of asbestos-related diseases in Italy in the last 5 years, from both a chronological and geographical perspective. Methods Ascertained diagnoses of asbestos-related diseases among workers were collected from the INAIL public registry from 2014 to 2018. Yearly incidence rate was estimated per province (incident cases per million workers) and mapped by year. Global incidence quota by working sector and sub-sector was also calculated. Results 8.620 cases have been reported. Incidence rate rapidly increased from 2014, peaking at 7,2 new cases per 100.000 workers in 2015. Afterwards, the number of ascertained cases decreased. There is a clear gradient distribution between northern and southern Italian provinces, with the highest rates in Northern Italy (especially in year 2014) and declining over time. Mesothelioma (all variants) was the most common disease, (2.995 cases, 35% of total), followed by pleural plaques (2.955 cases, 34%), pneumoconiosis (1.327 cases, 15%) and cancer of lungs/respiratory tract (1.298 cases, 14%). Most affected category was that of metal workers, but construction, transportation and electricity workers were also affected. Conclusions Detailed surveillance with mapping support is an effective tool for public health servants to locally manage prevention programs targeted on occupational risk. This is especially true for areas with active industries in the most affected sectors. Key messages Asbestos does not mean mesothelioma, but also other diseases that impact on workforce health status. Pneumoconiosis and other oral and respiratory cancers are also associated with asbestos exposure. Risk management should be tailored for a wider array of worker types than usually considered, since such exposure happens in sectors that are not traditionally related to asbestos exposure.

Voluntary Exercise in Mesothelioma: Effects on Tumour Growth and Treatment Response in a Murine Model

Objective There is substantial evidence that exercise can safely reduce the risk of cancer and improve survival in different human cancer populations. Long latency periods associated with carcinogeninduced cancers like asbestos induced mesothelioma provide an opportunity to implement exercise as an intervention to delay or prevent disease development. However, there are limited studies investigating the ability of exercise to prevent or delay cancer, and exercise as a preventive strategy has never been assessed in models with a known carcinogen. We investigated the potential of voluntary exercise (VE) to delay development of asbestos related disease (ARD) in our well-characterised, asbestos induced MexTAg model of mesothelioma. Results Asbestos exposed MexTAg mice were given continuous or delayed access to VE and ARD assessed over time. We found that the addition of VE did not affect ARD development in asbestos exposed MexTAg mice. However, nonasbestos exposed, aged matched control mice participated in significantly more VE behaviours, suggesting subclinical development of ARD after asbestos exposure had a greater impact on VE participation than age alone. These data highlight the importance of model choice and the potential limitation that some preclinical studies may not accurately represent the clinical paradigm, particularly in the context of prevention studies.