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Background We investigated mortality in workers of the world's largest chrysotile mine and enrichment factories located in the town of Asbest, Russian Federation. Methods This historical cohort study included all workers employed for at least 1 year between 1975 and 2010 and follow-up until the end of 2015. Cumulative exposure to dust was estimated based on workers' complete occupational history linked to dust measurements systematically collected from the 1950s. Exposure to chrysotile fibers was estimated using dust-to-fiber conversion factors. Relative risks (RRs) and 95% confidence intervals (CIs) were estimated as mortality rate ratios in Poisson regression models. Results A total of 30 445 (32% women) workers accumulated 721 312 person-years at risk and 11 110 (36%) died. Of the workers, 54% had more than 30 years since their first exposure. We found an exposure-response between cumulative dust and lung cancer mortality in men. No clear association with dust exposure but a modest increase in the highest category of fiber exposure was seen for lung cancer in women. Mesothelioma mortality was increased (RR = 7.64, 95% CI = 1.18 to 49.5, to at least 80 fibers per cm3 years and RR = 4.56, 95% CI = 0.94 to 22.1, to at least 150 mg/m3 years [dust]), based on 13 deaths. For colorectal and stomach cancer, there were inconsistent associations. No associations were seen for laryngeal or ovarian cancer. Conclusion In this large-scale epidemiological study in the world's largest active asbestos mine, we confirmed an increased risk of mesothelioma with high fiber exposure and an increasing mortality for lung cancer in men with increasing dust exposure. Less clear-cut increased lung cancer mortality was seen in the women. Continued mortality follow-up is warranted. [ABSTRACT FROM AUTHOR]

Bladder cancer is primarily diagnosed as non–muscle-invasive bladder cancer (NMIBC), with high recurrence and progression rates. Environmental and occupational exposures to carcinogens are well-known risk factors for developing bladder cancer, yet their effects on prognosis remain unknown. In the Be-Well Study, a population-based prospective cohort study of 1472 Kaiser Permanente patients newly diagnosed with NMIBC in California from 2015 to 2019, we examined history of environmental and occupational exposures in relation to tumor stage and grade at initial diagnosis by multivariable logistic regression, and subsequent recurrence and progression by Cox proportional hazards regression. Exposure to environmental and occupational carcinogens was significantly associated with increased risk of progression (hazard ratio (HR) = 1.79; 95% CI, 1.04-3.09), specifically with increased progression to muscle-invasive disease (HR = 2.28; 95% CI, 1.16-4.50). Exposures to asbestos and arsenic were associated with increased odds of advanced stage at diagnosis (asbestos: odds ratio (OR) = 1.43 [95% CI, 1.11-1.84]; arsenic: OR = 1.27 [95% CI, 1.01-1.63]), and formaldehyde exposure was associated with increased risk of recurrence (HR = 1.38; 95% CI, 1.12-1.69). Our findings suggest that considering a patient's history of these exposures may benefit current risk stratification systems in better tailoring clinical care and improving prognosis among patients with NMIBC. [ABSTRACT FROM AUTHOR]

Objectives In Italy, the highest pleural cancer mortality and incidence have been observed among Italian regions where the 2 largest Italian shipyards were (and are) located. The objective of this study was to assess the exposure–response relationship for mesothelioma among male workers employed in the Monfalcone, Italy, shipyard. Methods We conducted a necropsy-based case–control study. Cases (N = 102) were mesothelioma decedents and controls were those with lung cancer (N = 84). Complete job histories were available; the lung fibre content was measured using a scanning electron microscope with X-ray fluorescence, after sample preparation according to the European Respiratory Society guidelines. Odds ratios and 95% confidence intervals of mesothelioma by fibre type and lung fibre burden, as a categorical or continuous variable, were assessed by unconditional logistic regression, adjusted for age and time since exposure cessation. Analyses for the amphibole and chrysotile lung fibre burden were mutually adjusted. We calculated a cumulative exposure index by applying a job-exposure matrix to the job histories of study cases and assessed its correlation with the lung fibre burden. Results We found an odds ratio of 22.0 (confidence intervals 5.66–85.7) for the highest lung fibre burden category (mean 43.8 million total asbestos fibres per gram of dry tissue) compared with the reference (mean 0.48). Using log10-transformed lung fibre burden, we found that the odds ratio was 3.71 (confidence intervals 2.03–6.79) for a 10-fold lung fibre burden increase. Results for the amphibole lung fibre burden were similar. Odds ratios increased over chrysotile lung fibre burden categories (P -trend = 0.025), and the odds ratio for a 10-fold increase was 4.73 (confidence intervals 0.32–70.4). Conclusions The cumulative exposure index was correlated with total and amphibole lung fibre burden, but not with chrysotile lung fibre burden. Mesothelioma risk was proportional to total, amphibole, and chrysotile lung fibre burden in shipyard workers. [ABSTRACT FROM AUTHOR]

Since the manufacture, import, and use of asbestos products have been completely abolished in Japan, the main cause of asbestos emissions into the atmosphere is the demolition and removal of buildings built with asbestos-containing materials. To detect and correct asbestos emissions from inappropriate demolition and removal operations at an early stage, a rapid method to measure atmospheric asbestos fibers is required. The current rapid measurement method is a combination of short-term atmospheric sampling and phase-contrast microscopy counting. However, visual counting takes a considerable amount of time and is not sufficiently fast. Using artificial intelligence (AI) to analyze microscope images to detect fibers may greatly reduce the time required for counting. Therefore, in this study, we investigated the use of AI image analysis for detecting fibers in phase-contrast microscope images. A series of simulated atmospheric samples prepared from standard samples of amosite and chrysotile were observed using a phase-contrast microscope. Images were captured, and training datasets were created from the counting results of expert analysts. We adopted 2 types of AI models—an instance segmentation model, namely the mask region-based convolutional neural network (Mask R-CNN), and a semantic segmentation model, namely the multi-level aggregation network (MA-Net)—that were trained to detect asbestos fibers. The accuracy of fiber detection achieved with the Mask R-CNN model was 57% for recall and 46% for precision, whereas the accuracy achieved with the MA-Net model was 95% for recall and 91% for precision. Therefore, satisfactory results were obtained with the MA-Net model. The time required for fiber detection was less than 1 s per image in both AI models, which was faster than the time required for counting by an expert analyst. [ABSTRACT FROM AUTHOR]

The causal attribution of asbestos-related diseases to past asbestos exposures is of crucial importance in clinical and legal contexts. Often this evaluation is made based on the history of exposure, but this method presents important limitations. To assess past asbestos exposure, pleural plaques (PP), lung fibrosis and histological evidence of ferruginous bodies (FB) can be used in combination with anamnestic data. However, such markers have never been associated with a threshold value of inhaled asbestos. With this study we attempted to shed light on the dose–response relationship of PP, lung fibrosis and FBs, investigating if their prevalence in exposed individuals who died from malignant mesothelioma (MM) is related to the concentration of asbestos in lungs assessed using scanning electron microscopy equipped with energy dispersive spectroscopy. Moreover, we estimated the values of asbestos concentration in lungs associated with PP, lung fibrosis and FB. Lung fibrosis showed a significant positive relationship with asbestos lung content, whereas PP and FB did not. We identified, for the first time, critical lung concentrations of asbestos related to the presence of PP, lung fibrosis and FB at histology (respectively, 19 800, 26 400 and 27 400 fibers per gram of dry weight), that were all well-below the background levels of asbestos identified in our laboratory. Such data suggest that PP, lung fibrosis and FB at histology should be used with caution in the causal attribution of MM to past asbestos exposures, while evaluation of amphibole lung content using analytical electron microscopy should be preferred. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a heavy metal and natural element found in soil and crops with increasing concentrations linked to phosphate fertilizers and sewage sludge applied to crop lands. A large fraction of older US men and woman have documented Cd exposure. Cd exposure has proven health concerns such as risk of lung cancer from inhalation and impaired renal function; however, growing evidence suggests it also influences bone and muscle health. Given that low levels of Cd could affect bone and muscle, we have designed prospective studies using the two largest and most detailed US studies of bone health in older men and women: the Osteoporotic Fractures in Men Study and the Study of Osteoporotic Fractures. We are investigating the association of urinary cadmium (U-Cd), as a surrogate for long–term Cd exposure, with bone and muscle health. Building off suggestive evidence from mechanistic and cross–sectional studies, this will be the first well–powered prospective study of incident fracture outcomes, bone loss, and muscle loss in relation to U-Cd, an established biomarker of long–term Cd exposure. The following is a proposed protocol for the intended study; if successful, the proposed studies could be influential in directing future US policy to decrease Cd exposure in the US population similar to recent policies adopted by the European Union to limit Cd in fertilizers. [ABSTRACT FROM AUTHOR]

Asbestos cement (AC) is used in water pipes, roofing, exterior siding, water tanks, cooling towers, and other applications. Although the global market for asbestos is slowly shrinking, AC products continue to dominate the remaining uses in many countries. This review focuses on asbestos exposures during the installation, maintenance, and ultimate removal of these materials. This assessment summarizes the available published and unpublished reports of airborne asbestos exposures during the cutting and removal of AC pipes, roofing, sheets, and cooling tower components and the range of exposures associated with the most common work practices. Task-based exposures from cutting AC pipe ranged from 11.3 to 129.0 f/cm3 with a mean exposure of 53.8 f/cm3. Cutting flat boards and corrugated roofing AC sheets resulted in exposures ranging from 1.3 to 130.0 f/cm3 with a mean of 24.0 f/cm3. Exposures for power saw cutting of AC sheets and pipes fit lognormal distributions and suggest that more than 86% of these tasks with AC sheet and 100% of the tasks with AC pipe exceed the US short-term Excursion Limit. Intermittent high exposures from the ongoing use of AC products in countries around the world are associated with an increased lifetime risk of asbestos-related disease. [ABSTRACT FROM AUTHOR]

Background The association between asbestos exposure and ovarian cancer has been questioned given the possible misdiagnosis of peritoneal mesothelioma as ovarian cancer. Aims To update a systematic review on ovarian cancer risk in women occupationally exposed to asbestos, exploring the association with the time since first exposure and the duration of exposure. Methods We searched PubMed from 2008 onwards, screened previous systematic reviews, combined standardized mortality ratios (SMR) using random effect models and quantified heterogeneity using the I 2 statistic. To assess tumour misclassification, we compared the distribution of observed excess ovarian cancers (OEOC) to that expected (EEOC) from the distribution of peritoneal cancers in strata of latency and exposure duration. Results Eighteen publications (20 populations), including a pooled analysis of 21 cohorts, were included. The pooled SMR was 1.79 (95% confidence interval 1.38–2.31), with moderate heterogeneity between studies (I 2 = 42%), based on 144 ovarian cancer deaths/cases. The risk was increased for women with indirect indicators of higher exposure, longer duration and latency, and lower for chrysotile than for crocidolite exposure. The effect of duration and latency could not be completely disentangled, since no multivariate analysis was available for time-related variables. The dissimilarity index between OEOC and EEOC for the time since first exposure was small suggesting a similar pattern of risk. Conclusions While some misclassification between ovarian and peritoneal cancers cannot be excluded, the observed excess risk of ovarian cancer should be added to the overall disease burden of asbestos. [ABSTRACT FROM AUTHOR]

Although the use of asbestos fibres in building materials has been prohibited in Norway since 1985, asbestos-containing materials (ACMs) are still found in many buildings. Lack of knowledge and awareness of these materials may lead to exposure during refurbishing. The aim of this study was to investigate the airborne fibre concentration and classify fibres found during the abatement of various ACMs. The release of fibres during short-term work tasks, such as drilling and sawing, was also investigated. Parallel air samples were collected during asbestos abetment of different building materials and analysed with scanning electron microscope (SEM) and phase-contrast microscope (PCM), respectively. Material samples were analysed with SEM. A real-time fibre monitor was used to measure asbestos during short-term work. The highest fibre concentrations were measured for samples collected during the removal of asbestos insulating boards (1.5–4.5 fibres/cm3 [f/cm3]), and the numbers were relatively similar for SEM and PCM. A large difference in asbestos concentrations was found between SEM and PCM when analysing floor materials, which were probably caused by a high number of gypsum fibres that the PCM operator counted. Thin fibres (<0.2 µm in width) were included in the SEM count and constituted up to 50% of the total fibre concentration for the asbestos cement materials. The presence of other inorganic and organic fibres on these samples probably led to similar results between SEM and PCM. Short-term work led to peak concentrations above 30 f/cm3. [ABSTRACT FROM AUTHOR]

The South African National Institute for Occupational Health (NIOH), formerly the Pneumoconiosis Research Unit, has previously milled about 544 kg of anthophyllite, crocidolite, amosite and chrysotile asbestos fibre materials. This endeavour came about in an attempt to address a recommendation, made by the International Union Against Cancer (UICC), to make asbestos standard reference samples available for research. Some of these reference samples, as well as the bulk, unprocessed materials are still within the care of the NIOH and can be obtained for the purpose of Public Health research under strict terms and conditions. Considering the hazardous nature of asbestos and regulated prohibitions imposed on this mineral, the NIOH asbestos storage facility is being subjected to various occupational and environmental control measures to ensure that any potential fibre release, and subsequent risk of exposure, are prevented. [ABSTRACT FROM AUTHOR]

Objectives The Asbestos Removal Exposure Assessment Tool (AREAT) was previously developed to estimate exposure to respirable asbestos fibres during abatement processes. The current study describes the validation and recalibration of the AREAT model with external data. During model validation, the AREAT model was expanded to be able to estimate asbestos exposure from an additional source category: 'unspecified asbestos remnants'. Methods The validation dataset (n = 281) was derived from exposure measurement studies where for each exposure measurement the AREAT model parameters were coded and estimates were calculated. Pearson correlation coefficients (r) and intra class correlation coefficients (icc) were calculated as an indication of the agreement between the AREAT estimates and measured concentrations. In addition, the bias and the proportion of measurements with higher concentrations than model estimates were calculated. To expand and investigate model performance on exposure from 'unspecified asbestos remnants', a separate dataset was created with measurements collected during working with unspecified asbestos remnants, and similar validation comparisons were performed. Lastly, linear regression techniques were used to investigate possible improvements in model parameters. The model was recalibrated on a combined dataset consisting of the validation dataset and the original calibration dataset to increase model robustness. Results The validation comparisons showed good relative agreement (r) between AREAT estimates and measurements (r = 0.73) and a moderate absolute agreement (icc = 0.53). The overall relative bias was 108%, indicating an overall overestimation of exposure, and 4% of the estimated concentrations were higher than the actual measured concentrations. For the data subset concerning unspecified asbestos remnants, a moderate correlation between model estimates and measurement outcomes was found (r = 0.63). However, based on the low number of data in this subset, and moderate r , it was decided that cleaning of unspecified asbestos remnants is out of scope until more data are available. The results of this validation study suggested that two input parameters (product type friable material, efficacy of control measure foam) underestimated exposure. The effects of these parameters were updated to improve model performance. Compared to the original model, the recalibrated model resulted in slightly higher explained variance (62% compared to 56%) and lower uncertainty (15 compared to 17.3). Conclusion The original AREAT model provided reliable asbestos exposure estimates with a sufficient level of conservatism taking into account the 90-percentile estimates. The model was further improved via the addition of a new feature and recalibration to predict asbestos exposure during the clean-up of unspecified asbestos remnants. [ABSTRACT FROM AUTHOR]

Objective Asbestos use has decreased over time but occupational exposure still exists today due to the presence of asbestos in older buildings. The objective of this study was to update CAREX Canada's prevalence of exposure estimate from 2006 to 2016, and to assess the level of occupational exposure by industry, occupation, province/territory, and sex. Methods Estimates by occupation, industry, province/territory, and sex were calculated using labor force data from the 2016 Census of Population and proportions of workers exposed by occupation and industry, which were previously developed for the 2006 estimates and updated here to reflect new knowledge and changes in exposures. Statistics Canada concordance tables were used to account for changes between the 2006 and 2016 job and industry coding systems. Expert assessment was used to qualitatively assign levels of exposure (low, moderate, or high) for each occupation and industry, with consideration of workers' proximity and access to asbestos-containing material, and the condition and content of asbestos. Results Approximately 235 000 workers are exposed to asbestos on the job in Canada. The majority of Canadian workers exposed to asbestos are male (89%). Only 5% of all exposed workers are in the high-exposure category, while most workers are in the low (49%) or moderate (46%) exposure categories. The construction sector and associated jobs (e.g. carpenters, trades helpers and laborers, electricians) accounted for the majority of exposed workers. Conclusions Occupational exposure to asbestos continues to occur in Canada. Updating the prevalence of exposure estimate and adding exposure levels highlights the shift from high to lower-lever exposures associated with asbestos-containing materials remaining in the built environment. [ABSTRACT FROM AUTHOR]

Mesothelioma is an aggressive lung cancer, harms the linings of the lungs. It is one of the deadliest cancers diagnosed in those exposed to fibrous silicate minerals (asbestos). Millions of people face severe consequences as they are diagnosed at late stages. This study presents a comparison of several machine learning approaches with distinct feature sets and addresses the issue of class imbalance. The dataset used in this study is available publicly on the University of California Irvine (UCI) machine learning repository. This study used the resampling technique, synthetic minority oversampling technique (SMOTE) , and adaptive synthetic sampling (ADASYN) to handle the class imbalance. Most of the machine learning strategies performed well with the resampling technique. The best accuracy using the resampling strategy was achieved by artificial neural networks (ANN). The highest accuracy was recorded on the feature set selected by principal component analysis (PCA) is 96%. Overall, ensemble techniques performed well. The proposed stacking-based classifier achieved the highest accuracy (89%) on data balanced using SMOTE and ADASYN. [ABSTRACT FROM AUTHOR]

Background In both the epidemiological and legal context, the causal attribution of asbestos-related lung diseases requires retrospective exposure assessment (REA). Aims To assess the correlation between the retrospective assessment of occupational and anthropogenic environmental exposure to asbestos and its content in the lung tissue. Methods Based on the available exposure information, a team of occupational physicians retrospectively assessed cumulative exposure to asbestos in 24 subjects who died of asbestos-related diseases. The asbestos lung content was analysed using analytical scanning electron microscope (SEM-EDS). The Log10 asbestos fibre count in the autoptic samples was predicted as a function of the Log10 estimated cumulative exposure using univariate regression analysis. Results The median count of asbestos fibres by grams of dry weight (ff/gdw) in the lung tissue was 81 339 (range 0–2 135 849.06); it was 287 144 (range 0–2 135 849.06) among the occupationally exposed, and 29 671 (range 0–116 891) among the subjects who only had anthropogenic environmental and/or household exposure. Amphiboles, and particularly amosite (52%) and crocidolite (43%), were detected in all the study subjects. Chrysotile was not detected in any of the samples. Overall, the retrospective estimate of lifetime cumulative exposure to asbestos showed a moderate correlation with the total asbestos fibre count in the autoptic lung, with the regression model explaining 38–55% of the total variance. Conclusions Detailed information on occupational, environmental and household exposure circumstances would be indispensable for experienced industrial hygienists and/or occupational physicians to reliably assess past exposure to amphiboles or mixed types of asbestos. [ABSTRACT FROM AUTHOR]

In occupational epidemiology, job coding is an important—but time-consuming—step in assigning exposure. We implemented a tool (i.e. a crosswalk) to translate occupation codes from the Italian (ISTAT-CIP-91, n = 6319 five-digit job codes) to the International Standard Classification of Occupations (ISCO-68, n = 1881 five-digit job codes). The former is currently used in Italy for various purposes (e.g. in the National Mesothelioma Registry). The latter has been used in several studies on occupational cancers because it facilitates communication of results to the scientific community and, most importantly, because some job exposure matrices (JEMs) are based on international codes. Three authors created a table containing the crosswalk structure, providing an interpretation for each of the ISTAT-CIP-91 codes job descriptions and then manually recoding them according to ISCO-68. Two other authors independently revised it. The performance of the final version was assessed by comparison with results obtained by manual ISCO-68 coding performed in two previous case-control studies on asbestos and mesothelioma. More specifically, the automatically obtained ISCO-68 codes were merged with a JEM (DOM-JEM). The resulting individual asbestos exposure estimates (ever versus never exposed) were compared to those originally obtained (using the same DOM-JEM) from manual translation of ISTAT-CIP-91 to ISCO-68 (considered as the 'gold standard'). In the first study, among 159 peritoneal mesothelioma cases (400 job codes), Cohen's kappa was 0.91, sensitivity 0.95, and specificity 0.96. In the second study, among 716 pleural mesothelioma cases and controls (4400 job codes) kappa was 0.86, sensitivity 0.94, and specificity 0.91. Performance was better among in women. For men, performance was lower among cases than among controls (kappa 0.70, sensitivity 0.95, specificity 0.72 versus kappa 0.87, sensitivity 0.97, and specificity 0.92). In conclusion, the proposed tool allowed a rapid translation of thousands of job codes with good to excellent accuracy. The table containing ISTAT-CIP-91 codes and job descriptions and the corresponding ISCO-68 codes and job descriptions is made publicly available and can be freely used for epidemiological analyses in Italy and international collaborations. [ABSTRACT FROM AUTHOR]

Asbestos fibre counting by phase-contrast microscope is subject to many sources of variation, including those dependent on the analyst. In this study, asbestos sample slides prepared with relocatable coverslips have been used for fibre counting among voluntary analysts to evaluate their proficiency. One slide of amosite and one of chrysotile were distributed to all the analysts, and three proficiency testing rounds were conducted for amosite and four for chrysotile. Each relocatable coverslip has a report in which are reported for each viewing field both the number of certified fibres (Verified Fibres) and a drawing representing the shape and position of the individual fibres. In the first round, the analysts were asked to report only the number of fibres counted in each of the predesignated fields of view. In the other rounds, subsequently developed, the analysts had to report the number and the position of the fibres for each field. The reported number of fibres and their position in each of the designed fields were evaluated against their respective verified fibres, to identify types of error. Discrepancies between reported fibres and verified fibres in each field of view have been used to evaluate the proficiency of the analysts. The discrepancies can be positive (D+) or negative (D−) depending on whether the analyst counts, for a specific field of view, more or less fibres compared to the verified fibres. The score is calculated using the following equation: Score = (1 − ∑D+ + ∑│D−│/VF) × 100. An analyst obtaining a score of ≥60, which corresponds to (∑ D + + ∑│ D −│)/VF ≤ 0.40, is proficient. The number of laboratories that participating in this study varied from 13 to 17 depending on the rounds. For amosite fibre counts, the results were generally good compared to a proficiency score of 60. The major error made by analysts was the counting of fibres shorter than 5 µm, where this error was of 62% of extra fibres and accounted for 8% over-estimation of amosite fibres. For chrysotile, a score of ≥50 has been used to consider an analyst as proficient. The results of chrysotile fibres showed that in the first round all analysts counted less than fifty per cent of the verified fibres. In the second round 10 analysts out of 13 reached a score of ≥50, 8 of 16 in the third and 10 of 12 in the fourth. For chrysotile fibres, the error relating to the counting of fibres shorter than 5 µm was of 56% of extra fibres, but the error that most influenced the results was the number of oversight-missing fibres. This type of error accounted for 97% of the missing fibres and for the 29% under-estimation of the chrysotile fibres. For amosite fibre counting, results of this study show an improvement of the analyst's performance. For the chrysotile fibre count, although there is a significant improvement in the comparison between some rounds, this is not continuous over time. [ABSTRACT FROM AUTHOR]

Malignant pleural mesothelioma (MPM) is a highly malignant disease that develops after asbestos exposure. Although the number of MPM cases is predicted to increase, no effective standard therapies have been established. The novel radiosensitizer α-sulfoquinovosyl-acylpropanediol (SQAP) enhances the effects of γ-radiation in human lung and prostate cancer cell lines and in animal models. In this study, we explored the radiosensitizing effect of SQAP and its mechanisms in MPM. The human MPM cell lines MSTO-211H and MESO-4 were implanted subcutaneously into the backs and thoracic cavities of immunodeficient KSN/Slc mice, then 2 mg/kg SQAP was intravenously administered with or without irradiation with a total body dose of 8 Gy. In both the orthotopic and ectopic xenograft murine models, the combination of irradiation plus SQAP delayed the implanted human MSTO-211H tumor growth. The analysis of the changes in the relative tumor volume of the MSTO-211H indicated a statistically significant difference after 8 Gy total body combined with 2 mg/kg SQAP, compared to both the untreated control (P  = 0.0127) and the radiation treatment alone (P  = 0.0171). After the treatment in each case, immunostaining of the harvested tumors revealed decreased cell proliferation, increased apoptosis and normalization of tumor blood vessels in the SQAP- and irradiation-treated group. Furthermore, hypoxia-inducible factor (HIF) 1 mRNA and protein expression were decreased, indicating reoxygenation in this group. In conclusion, SQAP improved hypoxic conditions in tumor tissue and may elicit a radiosensitizing effect in malignant mesothelioma models. [ABSTRACT FROM AUTHOR]

The aim of the study was to find out good practices for effective air distribution inside a complex shaped asbestos enclosure and for control of pressure differences between the enclosure and the surroundings. In addition, sufficient pressure difference for asbestos containment was tested. The effect of air distribution was studied in laboratory conditions by constructing an L-shaped asbestos enclosure and connecting it to a negative pressure unit. The efficiency of six different ventilation configurations was compared using a tracer decay method and the local air change indexes as the performance indicator. The sufficient negative pressure for containment was assessed by simulating person traffic to and from the enclosure and recording the pressure difference continuously. The effect of a pressure controller unit in maintaining the target pressure difference was also tested by simulating filter loadings of the negative pressure unit causing changes in the air flow rate. The results showed that high nominal air change rates alone do not guarantee good air distribution. Effective air distribution within an asbestos enclosure can be arranged by locating additional air supply openings far away from the air exhaustion point, using recirculation air with a pressure controller, or extending the exhaust location to the poorly ventilated areas. A pressure difference of at least −10 Pa is recommended to ensure a sufficient margin of safety in practical situations. [ABSTRACT FROM AUTHOR]

Exposure to asbestos fibres is linked to numerous adverse health effects and the use of asbestos is currently banned in many countries. Still, asbestos applications are present in numerous residential and professional/industrial buildings or installations which need to be removed. Exposure measurements give good insight in exposure levels on the basis of which the required control regime is determined to ensure that workers are protected against adverse health effects. However, it is a costly and time-consuming process to measure all situations as working conditions and materials may vary greatly. Therefore, the mechanistic model 'Asbestos Removal Exposure Assessment Tool (AREAT)' was developed to estimate exposure to respirable asbestos fibres released during asbestos abatement processes where measurements are not available. In such instances tailored control regimes can be implemented based on modelled exposure levels. The mechanistic model was developed using scientific literature, an in-house asbestos abatement dataset, and knowledge with regard to previously developed models. Several exposure determinants such as the substance emission potential, activity emission potential, control measures, and dilution in air were identified and specific modifiers were developed for each category. Through an algorithm, AREAT calculates a dimensionless score based on the model inputs. The model was calibrated using a statistical model on an extensive measurement dataset containing a broad variety of exposure scenarios. This statistical model enabled the translation of dimensionless AREAT scores to actual estimated fibre concentrations in fibres m−3. In total, 370 personal inhalation exposure measurements from 71 different studies were used for calibration of AREAT. Of these measurements, in 191 cases (52%) with microscopic analysis (all asbestos fibre analyses were conducted with scanning electron microscopy/energy dispersive X-ray analysis in accordance with ISO 14966) no fibres were detected and the limit of detection values(LODs) were given. To assess the influence of the large number of measurements with exposures below LOD values on the performance of the model, calibrations were performed on the total dataset and the selection of data excluding measurements below LOD. The AREAT model correlated well with the datasets, with a Pearson correlation of 0.73 and 0.8 and Spearman rank correlation of 0.56 and 0.8. The model was fitted to estimate a typical exposure value [i.e. geometric mean (GM) exposures], but it is recommended to use a more conservative worst case higher percentile (for example the 90th percentile; which adds a factor of 17.3 based on the model uncertainty on the GM estimate), to account for variability in the measurements and uncertainty in model estimates. This work has shown the development and calibration of a mechanistic model, capable of estimating asbestos fibre exposures during asbestos abatement processes. The AREAT model will be implemented as a lower tier exposure model in a risk assessment tool used within the Netherlands to plan abatement processes and to develop control strategies. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Recently, several malignant peritoneal mesotheliomas (MPMs), occurring in young women without asbestos exposure and with fusion genes such as anaplastic lymphoma kinase (ALK) and Ewing sarcoma breakpoint region 1, have been reported. In the present case, we encountered MPM with STRN‐ALK fusion in a 17‐year‐old female adolescent. The case did not respond to chemotherapy and is currently in a clinical trial of alectinib. This is the fourth reported case of MPM with STRN‐ALK fusion. Of the 45 cancer cases with STRN‐ALK fusion in which the fusion partners were examined, all cases except for the current case showed fusion of exon 3 of STRN and exon 20 of ALK. This is the first case with fusion of exon 2 of STRN and exon 20 of ALK. Further advances in cancer genomic medicine may help clarify the clinical significance of this new fusion. Key Points: Malignant peritoneal mesotheliomas (MPMs) can occur in young women without asbestos exposure and show fusion genes that activate anaplastic lymphoma kinase (ALK) by gene rearrangement.ALK rearrangement and the fusion partner can be detected by companion diagnostics and by next generation sequencing.Patients with MPMs with ALK rearrangement may benefit from target therapy. This article reports a case of malignant peritoneal mesothelioma (MPM) with STRN‐ALK fusion in a 17‐year‐old female, the first known case with fusion of exon 2 of STRN and exon 20 of ALK. [ABSTRACT FROM AUTHOR]

This is a report of a rare case of an infarcted pelvic intra-abdominal cyst, having no mesenteric connection presenting as an acute abdomen. The patient had significant asbestos exposure. The cyst was treated successfully by surgical excision. Histopathology showed an infarcted cyst; the lining was destroyed, precluding marker studies. A diagnosis of benign cystic peritoneal mesothelioma (BCPM) was made by excluding other causes of solitary pelvic intra-abdominal cysts. BCPM has been classified as an asbestos-related neoplasm and is usually seen in the pelvis adjunct to the urinary bladder. One-year post-surgery, there was no recurrence. The case report shows that infarcted pelvic mesothelial cysts can present as an acute abdomen and can be treated successfully by total excision with no recurrence. [ABSTRACT FROM AUTHOR]

Objectives An estimated 125 million workers are exposed to asbestos worldwide. Asbestos is classified by the International Agency for Research on Cancer as a Group 1 carcinogen. The association between occupational asbestos exposure and kidney cancer is not well established however. This study aimed to determine the mortality and incidence of kidney cancer in workers who have been exposed to asbestos. We performed a systematic review and meta-analysis to evaluate the association between occupational asbestos exposure and kidney cancer. Methods Medline, EMBASE, and Web of Science were searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for articles on occupational asbestos exposure and kidney cancer. The studies reported the standardized mortality ratio (SMR) or standardized incidence ratio (SIR) of kidney cancer in workers exposed to asbestos. SMRs or SIRs with its 95% confidence interval (CI) were pooled using a fixed-effect model. Results Forty-nine cohort studies involving 335 492 workers were selected for analysis. These studies included 468 kidney cancer deaths and 160 incident cases. The overall pooled-SMR of kidney cancer was 0.95 (95% CI: 0.86–1.05), with no significant heterogeneity (P Q = 0.09, I 2 = 24.87%). The overall pooled-SIR of kidney cancer was 0.95 (95% CI: 0.79–1.11), with no significant heterogeneity (P Q = 0.68, I 2 = 0.00%). Subgroup analysis did not find any increased association with occupational asbestos exposure. There was no evidence of publication bias with Egger's test P values of 0.08 for mortality studies and 0.99 for incidence studies. Conclusions This systematic review and meta-analysis did not show evidence of association between occupational asbestos exposure and kidney cancer mortality or incidence. [ABSTRACT FROM AUTHOR]

Despite numerous studies of asbestos workers in the epidemiologic literature, there are very few cohort studies of chrysotile asbestos miners/millers that include high-quality retrospective exposure assessments. As part of the creation of the Baie Verte Miners' Registry in 2008, a two-dimensional job exposure matrix (JEM) was developed for estimating asbestos exposures for former chrysotile asbestos miners/millers. Industrial hygiene data collected between 1963 and 1994 were analysed to assess validity for use in a retrospective exposure assessment and epidemiologic study. Registered former employees were divided into 52 exposure groups (EGs) based on job title and department and mean asbestos concentrations were calculated for each EG. The resulting exposure estimates were linked to individual registrants' work histories allowing for the calculation of cumulative asbestos exposure for each registrant. The distribution of exposure for most EGs (82.6%) could be described as fitting a log-normal distribution, although variability within some EGs (55%) exceeded a geometric standard deviation (GSD) of 2.5. Overall, the data used to create EGs in the development of the JEM were deemed to be of adequate quality for estimating cumulative asbestos exposures for the former employees of the Baie Verte asbestos mine/mill. The variability between workers in the same job was often high and is an important factor to be considered when using estimates of cumulative asbestos exposure to adjudicate compensation claims. The exposures experienced in this cohort were comparable to those of other chrysotile asbestos miners/millers cohorts, specifically Italian and Québec cohorts. [ABSTRACT FROM AUTHOR]

Asbestos is the main causative agent of malignant pleural mesothelioma. The variety known as crocidolite (blue asbestos) owns the highest pathogenic potential, due to the dimensions of its fibers as well as to its content of iron. The latter can in fact react with macrophage-derived hydrogen peroxide in the so called Fenton reaction, giving rise to highly reactive and mutagenic hydroxyl radical. On the other hand, hydroxyl radical can as well originate after thiol-dependent reduction of iron, a process capable of starting its redox cycling. Previous studies showed that glutathione (GSH) is one such thiol, and that cellular gamma-glutamyltransferase (GGT) can efficiently potentiate GSH-dependent iron redox cycling and consequent oxidative stress. As GGT is expressed in macrophages and is released upon their activation, the present study was aimed at verifying the hypothesis that GSH/GGT-dependent redox reactions may participate in the oxidative stress following the activation of macrophages induced by crocidolite asbestos. Experiments in acellular systems confirmed that GGT-mediated metabolism of GSH can potentiate crocidolite-dependent production of superoxide anion, through the production of highly reactive dipeptide thiol cysteinyl-glycine. Cultured THP-1 macrophagic cells, as well as isolated monocytes obtained from healthy donors and differentiated to macrophages in vitro , were investigated as to their expression of GGT and the effects of exposure to crocidolite. The results show that crocidolite asbestos at subtoxic concentrations (50–250 ng/1000 cells) can upregulate GGT expression, which raises the possibility that macrophage-initiated, GSH/GGT-dependent pro-oxidant reactions may participate in the pathogenesis of tissue damage and inflammation consequent to crocidolite intoxication. [ABSTRACT FROM AUTHOR]

Background Asbestos is a well-known carcinogen for humans. The aim of this study is to develop a tool to estimate occupational asbestos exposure in Italy after the ban using information collected in a national dataset. Methods Data were collected from firm registries of workers exposed to asbestos in the period 1996–2016. Descriptive statistics (arithmetic mean, standard deviation, geometric mean and geometric standard deviation) were calculated for the main exposure-related variables (activity sector, occupational group and exposure period). An estimate of workers potentially exposed to asbestos was also performed. Results A total of 19 704 airborne measurements of asbestos exposure was selected from the national database of occupational exposures in the sectors of asbestos abatement. Overall, a geometric mean of 7.93 f l−1 was found, and chrysotile was the asbestos type that had more exposures (41%). A total of 46 422 workers was estimated to be potentially at asbestos exposure risk. Exposure data were summarized by calendar period, activity sector and occupational group. Conclusions The construction of a job exposure matrix for different occupation/industry combinations may allow the assessment of occupational exposure to asbestos in several removal and disposal activities, and the estimate of the risks associated with asbestos-related diseases in epidemiological studies. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The largest chrysotile mine in Western Europe was active in Balangero (Italy) from 1917 to 1990. We quantitatively assessed exposure to asbestos in the framework of a cohort study on mortality of Balangero miners and millers. Using documents filed at the Italian State Archive we reconstructed the job-histories of cohort members. The concentration of asbestos fibres by work-area was derived from industrial hygiene surveys since 1968 and monitoring programs since 1975. Earlier exposures had been estimated based on the experimental reconstruction of past working conditions. In the mine concentrations of about 20 fibres per millilitre (f/ml) were initially present, decreasing to 5 in the mid-1950s and to <1 in late 1970s. In milling areas higher levels were present and did not fall below 1 f/ml until the mid-1980s. Cumulative exposure of cohort members, as the sum over their job-history of their year- and area-specific exposures, were <10 fibre/millilitre years (f/ml-y) in 18% of workers, 10–100 in 32%, 100–1000 in 37%, and >1000 in 13%. Compared with recently published estimates for the Russian chrysotile mine in Asbest, fibre concentrations in Balangero were higher during the 1950s and 1960s. Such difference may be partly accounted for by difficulties in converting dust measurements to fibre concentrations in the Russian study and the need to rely on the experimental reconstruction of exposures before 1968 in our study. [ABSTRACT FROM AUTHOR]

The Wittenoom crocidolite (blue asbestos) mine and mill ceased operating in 1966. The impact of this industry on asbestos-related disease in Western Australia has been immense. Use of the employment records of the Australian Blue Asbestos Company and records of the Wittenoom township residents has permitted two cohorts of people with virtually exclusive exposure to crocidolite to be assembled and studied. Follow-up of these two cohorts has been conducted through data linkage with available hospital, mortality and cancer records. The evolution of asbestos-related disease has been recorded and, with the establishment of exposure measurements, quantitative exposure-response relationships have been estimated. There has been an ongoing epidemic of mortality from lung cancer and malignant mesothelioma and, less so, from asbestosis. Wittenoom crocidolite was used extensively in asbestos-cement products in Western Australia. As a result, the state has recorded a higher malignant-mesothelioma mortality rate than in any other Australian state and in any defined general population in the world. Thus, the legacy of Wittenoom has extended beyond the mine and the town, and is still evident more than 50 years after the closure of the mine. [ABSTRACT FROM AUTHOR]

When government actors seek to restrict the sale of hazardous substances, industry actors tend to intervene, deploying coordinated strategies aimed at delaying, preventing or weakening attempts to regulate their products. In many cases, this has involved deliberate efforts to obfuscate science, mislead the public and manipulate political actors in order to ensure desired policy outcomes. Strategies of regulatory obstructionism have resulted in the prolonged dispersal of harmful chemical substances with tangible impacts on public health. This article proposes that this behavior should be interpreted as a form of violence. Examining the regulatory histories of lead, benzene, asbestos and PCBs, the article demonstrates how regulatory obstructionism and violence have become intractable characteristics of the chemical industry. [ABSTRACT FROM AUTHOR]

Toxic contaminants inadvertently brought from the workplace to the home, known as take-home or paraoccupational exposures, have often been framed as a problem that arises due to unsanitary worker behavior. This review article conceptualizes take-home exposures as a public health hazard by (i) investigating the history of take-home contaminants and how they have been studied, (ii) arguing that an ecosocial view of the problem is essential for effective prevention, (iii) summarizing key structural vulnerabilities that lead populations to be at risk, and (iv) discussing future research and prevention effort needs. This article reframes take-home exposures as one of many chronic pathways that contributes to persistent health disparities among workers, their families, and communities. Including the role of work in community health will increase the comprehensiveness of prevention efforts for contaminants such as lead and pesticides that contribute to environmental disparities. [ABSTRACT FROM AUTHOR]

The asbestos industry has always claimed that asbestos is a 'magic mineral', which is not replaceable. New findings, however, contradict this because asbestos-free alternatives, with excellent insulating properties, have been available since the end of the nineteenth century. The aim of this current research is to gather evidence of the potential of 'Martinite' to replace asbestos. We identified references to 'Martinite' in documents and brochures pertaining to insulation of ships, dating back as far as possible by acquiring recent interviews, utilizing records in public libraries and in archives, and conducting web searches. Martinite was produced by a small company called 'Manifatture Martiny', founded at the end of the nineteenth century in Turin, Italy. This company was specialized in insulation materials production, such as cork, rubber, foams, and even asbestos. In the early twentieth century, Martinite was utilized in warships of the Royal Italian Navy. During this time, it was patented in Italy and in many other industrialized nations. It was also utilized in construction of civilian power plants and was approved by the Architects Corporation in 1940. Furthermore, it was licenced in 1950 by the Italian National Naval Certification Body (UNAV) to be used on ships. We argue that had Martinite been properly advertised and distributed, it could have been used worldwide in place of asbestos for some applications, resulting in a lower incidence of serious and fatal diseases. The small scale of the company, compared to those of the asbestos multinationals, contributed to the lack of commercial development of the product. [ABSTRACT FROM AUTHOR]

There is an ongoing argument about the potency of chrysotile asbestos to cause malignant mesothelioma. Authors of chrysotile risk assessments have relied upon the results of an epidemiologic study, published in 1984, to state that there were no mesotheliomas found among workers at a Connecticut friction products plant. McDonald reported the first two cases in 1986. In 2010, we reported the work histories and pathologic reports of five individuals from the Connecticut plant who were diagnosed with mesothelioma. Despite this, a review of the health effects of chrysotile published in 2018 continued to state that there were no cases of mesothelioma from this plant. We report here two new cases that were diagnosed after the publication of our previous report, bringing the current total to nine cases. We also discuss the results of previously unpublished air sampling data from the plant. Chrysotile, mainly from Canada, was the only asbestos fiber type used until 1957 when some anthophyllite was added in making paper discs and bands. Beyond this original description of the anthophyllite usage from McDonald, there is a dearth of information about the amount of anthophyllite used in the plant, the frequency of its use, and the specific departments where it was used. For over 30 years in the published literature, this factory has alternatively been described as a 'chrysotile' or 'predominantly chrysotile' factory. While it is clear that some anthophyllite was used in the factory (in addition to 400 pounds of crocidolite in the laboratory), given the volume, frequency, and processes using chrysotile, it still seems satisfactory to describe this cohort as a predominantly, but not exclusively, chrysotile-exposed cohort. [ABSTRACT FROM AUTHOR]

Objectives: In Japan, benign asbestos pleural effusion (BAPE) has been eligible for industrial accident compensation since 2003 as an asbestos‐related disease despite the lack of good criteria. We compiled a criteria into a checklist of essential items and for excluding other diseases inducing pleural effusion as a diagnosis process. Method: Thoracentesis was performed in order to confirm the presence of pleural effusion at the initial diagnosis, and 105 suspected BAPE patients were retrospectively examined. We complied a checklist comprising the following diagnostic items: (a) occupational asbestos exposure; (b) confirmation of exudate of pleural effusion; (c) exclusion of pleural effusion with malignant tumors based on negative results of CEA and hyaluronic acid, and cytology of pleural effusion; (d) exclusion of rheumatic, bacterial, and tuberculous pleuritis; (d) radiological findings for exclusion of malignancies; and (e) histopathological findings based on thoracoscopy that exclude malignancies (when thoracoscopy was not performed, there was confirmation that no malignancies were present during 3‐month follow‐up observation). Cases that satisfied all items were defined as BAPE. Results: Among the 105 suspected cases, there were five cases that had no occupational asbestos exposure; six cases in which transudate of on pleural effusion; one case each of rheumatoid pleuritis and tuberculous pleuritis; and five cases of pleural mesothelioma based on chest radiography and histopathological findings within 3 months after initial diagnosis. Therefore, we excluded 18 cases from the 105 candidates and determined 87 cases of BAPE. Conclusion: We consider that six items described above are suitable for diagnosing BAPE. [ABSTRACT FROM AUTHOR]

We extended the mortality follow-up of a cohort of 25,460 workers employed at 8 acrylonitrile (AN)-producing facilities in the United States by 21 years. Using 8,124 deaths and 1,023,922 person-years of follow-up, we evaluated the relationship between occupational AN exposure and death. Standardized mortality ratios (SMRs) based on deaths through December 31, 2011, were calculated. Work histories and monitoring data were used to develop quantitative estimates of AN exposure. Hazard ratios were estimated by Cox proportional hazards regression. All-cause mortality and death from total cancer were less than expected compared with the US population. We observed an excess of death due to mesothelioma (SMR = 2.24, 95% confidence interval (CI): 1.39, 3.42); no other SMRs were elevated overall. Cox regression analyses revealed an elevated risk of lung and bronchial cancer (n = 808 deaths; for >12.1 ppm-year vs. unexposed, hazard ratio (HR) = 1.43, 95% CI: 1.13, 1.81; P for trend = 0.05), lagged 10 years, that was robust in sensitivity analyses adjusted for smoking and co-exposures including asbestos. Death resulting from bladder cancer (for >2.56 ppm vs. unexposed, lagged 10-year HR = 2.96, 95% CI: 1.38, 6.34; P for trend = 0.02) and pneumonitis (for >3.12 ppm-year vs. unexposed, HR = 4.73, 95% CI: 1.42, 15.76; P for trend = 0.007) was also associated with AN exposure. We provide additional evidence of an association between AN exposure and lung cancer, as well as possible increased risk for death due to bladder cancer and pneumonitis. [ABSTRACT FROM AUTHOR]

Objectives An asbestos job-exposure matrix (AsbJEM) has been developed to systematically and cost-effectively evaluate occupational exposures in population-based studies. The primary aim of this study was to examine the accuracy of the AsbJEM in determining exposure–response relationships between asbestos exposure estimates and malignant mesothelioma (MM) incidence (indirect validation). The secondary aim was to investigate whether the assumptions used in the development of the original AsbJEM provided accurate asbestos exposure estimates. Methods The study population consisted of participants in an annual health surveillance program, who had at least 3-month occupational asbestos exposure. Calculated asbestos exposure indices included cumulative asbestos exposure and the average exposure intensity, estimated using the AsbJEM and duration of employment. Asbestos and MM exposure–response relationships were compared between the original AsbJEM and its variations based on manipulations of the intensity, duration and frequency of exposure. Twenty-four exposure estimates were calculated for both cumulative asbestos exposure and the average exposure intensity using three exposure intensities (50th, 75th and 90th percentile of the range of mode exposure), four peak durations (15, 30, 60 and 120 min) and two patterns of peak frequency (original and doubled). Cox proportional hazards models were used to describe the associations between MM incidence and each of the cumulative and average intensity estimates. Results Data were collected from 1602 male participants. Of these, 40 developed MM during the study period. There were significant associations between MM incidence and both cumulative and average exposure intensity for all estimates. The strongest association, based on the regression-coefficient from the models, was found for the 50th percentile of mode exposure, 15-min peak duration and the doubled frequency of peak exposure. Using these assumptions, the hazard ratios for mesothelioma were 1 (reference), 1.91, 3.24 and 5.37 for the quartiles of cumulative asbestos exposure and 1 (reference), 1.84, 2.31 and 4.40 for the quartiles of the average exposure intensity, respectively. Conclusion The well-known positive exposure–response relationship between MM incidence and both estimated cumulative asbestos exposure and average exposure intensity was confirmed. The strongest relationship was found when the frequency of peak exposure in the AsbJEM was doubled from the originally published estimates. [ABSTRACT FROM AUTHOR]

Background: Occupational and environmental airborne asbestos concentrations are too low and variable for lifetime exposures to be estimated reliably, and building workers and occupants may suffer higher exposure when asbestos in older buildings is disturbed or removed. Mesothelioma risks from current asbestos exposures are therefore not known.Methods: We interviewed and measured asbestos levels in lung samples from 257 patients treated for pneumothorax and 262 with resected lung cancer, recruited in England and Wales. Average lung burdens in British birth cohorts from 1940 to 1992 were estimated for asbestos-exposed workers and the general population.Results: Regression analysis of British mesothelioma death rates and average lung burdens in birth cohorts born before 1965 suggests a lifetime mesothelioma risk of approximately 0.01% per fibre/mg of amphiboles in the lung. In those born since 1965, the average lung burden is ∼1 fibre/mg among those with no occupational exposure.Conclusions: The average lifetime mesothelioma risk caused by recent environmental asbestos exposure in Britain will be about 1 in 10 000. The risk is an order of magnitude higher in a subgroup of exposed workers and probably in occupants in the most contaminated buildings. Further data are needed to discover whether asbestos still present in buildings, particularly schools, is a persistent or decreasing hazard to workers who disturb it and to the general population, and whether environmental exposure occurs predominantly in childhood or after beginning work. Similar studies are needed in other countries to estimate continuing environmental and occupational mesothelioma hazards worldwide, including the contribution from chrysotile. [ABSTRACT FROM AUTHOR]

Background: We previously showed that low-dose computed tomography (LDCT) screening in asbestos-exposed workers is effective in detecting lung cancer (LC) at an early stage. Here, we evaluate whether LDCT screening could reduce mortality from LC in such a high-risk population.Methods: Within a cohort of 2433 asbestos-exposed men enrolled in an Occupational Health surveillance programme, we compared mortality between the participants in the ATOM002 study (LDCT-P, N  =  926) and contemporary non-participants (LDCT-NP, N  =  1507). We estimated standardized mortality ratios for the LDCT-P and LDCT-NP populations using regional and national rates (SMR_FVG and SMR_ITA, respectively). We compared survival for all causes, all neoplasms, LC and malignant neoplasm of pleura (MNP) between LDCT-P and LDCT-NP using Cox proportional hazard models adjusted for age, smoking history, asbestos exposure level and comorbidities.Results: A reduction in mortality from LC was observed in the LDCT-P group compared with regional and national figures (SMR_FVG  =  0.55, 95% confidence interval (CI) 0.24-1.09; SMR_ITA  =  0.51, 95% CI 0.22-1.01); this was not the case for the LDCT-NP group (SMR_FVG  =  2.07, 95% CI 1.53-2.73; SMR_ITA  =  1.98, 95% CI 1.47-2.61). A strong reduction in LC mortality was observed for the LDCT-P compared with the LDCT-NP [hazard ratio (HR)  =  0.41, 95% CI 0.17-0.96]. Mortality was also reduced for all causes (HR  =  0.61, 95% CI 0.44-0.84), but not for all neoplasms (HR  =  0.97, 95% CI 0.62-1.50) and MNP (HR  =  0.86, 95% CI 0.31-2.41) within the LDCT-P population.Conclusions: In our cohort, participation in the LDCT screening study was associated with reduced mortality from LC. This finding supports the use of LDCT in surveillance programmes for asbestos-exposed workers. [ABSTRACT FROM AUTHOR]

Sarcomatoid malignant peritoneal mesothelioma is the rarest and most lethal form of peritoneal mesothelioma. We present the case of a sarcomatoid malignant peritoneal mesothelioma presenting as a localized mesenteric tumor in a 54-year-old female with no previous asbestos exposure. This clinical presentation is extremely rare and is the first documented in Cameroon. [ABSTRACT FROM AUTHOR]

Asbestos exposure is the main etiology of malignant mesothelioma, but there are conflicting data on whether the intensity of exposure modulates the development of this disease. This study considered 594 patients with malignant mesothelioma for whom count data on asbestos bodies and fibers (per gram of wet lung tissue) were available. The relationships between age at diagnosis (a time-to-event outcome variable) and these two measures of internal asbestos exposure, along with other possible modulating factors (sex, tumor location, histological subtype and childhood exposure), were assessed on multivariable Cox proportional hazard models, stratifying by decade of birth year. For both measures of asbestos in lung tissue, younger age at diagnosis was associated with higher internal measures of exposure to asbestos. Stratified Cox analyses showed that for each doubling in asbestos body count patients were 1.07 times more likely to be diagnosed at a younger age [hazard ratio (HR) = 1.07; 95% confidence interval (CI), 1.04–1.09; P = 2.2 × 10−7] and for each doubling in asbestos fiber count patients were 1.13 times more likely to be diagnosed at a younger age (HR = 1.13; 95% CI, 1.09–1.17; P = 8.6 × 10−11). None of the other variables considered were associated with age at diagnosis. Our finding that tumors become clinically apparent at a younger age in heavily exposed subjects suggests that asbestos is involved not only in the malignant mesothelioma tumor initiation but, somehow, also in the progression of the disease. [ABSTRACT FROM AUTHOR]

Numerous changes have been made to the French labour regulations in recent years relating to the prevention of risks of exposure to asbestos fibres for operators removing asbestos-containing materials. These changes refer to the method used to count fibres, the collective and personal protective devices to be used on these worksites, and the occupational exposure limit value, which was reduced to 10 f.L−1 on 2 July 2015. In this context, this study assessed the level of respiratory protection afforded by supplied-air respirators and powered air-purifying respirators by monitoring exposure for several operators on nine worksites. The levels of dustiness measured in personal samples taken outside masks showed significant evidence of potential exposure during removal of asbestos-containing plaster or sprayed asbestos, and when using abrasive blasting to treat asbestos-containing materials. For these tasks outside concentration regularly exceeds 25000 f.L−1. Measurements inside masks were generally low, under 10 f.L−1, except in some situations involving the removal of asbestos-containing plaster. This partial penetration of fibres inside masks could be due to the high loading linked to this material. The distributions of Workplace Protection Factors obtained for the two types of respiratory protective devices studied were broad, and the fifth percentile values equal to 236 and 104, respectively, for supplied-air respirators and powered air-purifying respirators. This work highlights once again the need to prioritize collective protection when seeking to prevent asbestos-related risks. [ABSTRACT FROM AUTHOR]

Objectives: Mining and processing of chrysotile, an established carcinogen, has been undertaken in Asbest, Russian Federation since the late 1800s. Dust concentrations were routinely recorded at the open-pit mine and its asbestos-enrichment factories. We examined the temporal trends in these dust concentrations from 1951 to 2001. Methods: Analyses included 89 290 monthly averaged gravimetric dust concentrations in six factories (1951-2001) and 1457 monthly averaged concentrations in the mine (1964-2001). Annual percent changes (APC) in geometric mean dust concentrations were estimated for each factory and the mine separately from linear mixed models of the logarithmic-transformed monthly averaged concentrations. Results: Dust concentrations declined significantly in the mine [APC: -1.6%; 95% confidence interval (CI): -3.0 to -0.2] and Factories 1-5 but not 6. Overall factory APCs ranged from -30.4% (95% CI: -51.9 to -8.9; Factory 1: 1951-1955) to -0.6% (95% CI: -1.5 to 0.2; Factory 6: 1969-2001). Factory trends varied across decades, with the steepest declines observed before 1960 [APCs: -21.5% (Factory 2) and -17.4% (Factory 3)], more moderate declines in the 1960s and 1970s [APCs from -10% in Factory 2 (1960s) to -0.3% (not statistically significant) in Factory 4 (1970s)], and little change thereafter. Mine dust concentrations increased in the 1960s (APC: +9.7%; 95% CI: 3.6 to 15.9), decreased in the 1990s (APC: -5.8%; 95% CI: -8.1 to -3.5) and were stable in between. Conclusions: In this analysis of >90 000 dust concentrations, factory dust concentrations declined between 1951 and 1979 and then stabilized. In the mine, dust levels increased in the 1960s, declined in the 1990s and were unchanged in the interim. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Asbestos is known to be an independent risk factor for lung and pleural cancers. However, to date, little attention has been paid to the psychological effects of asbestos exposure among exposed subjects. The objectives of this study were to estimate the prevalence of anxious and depressive symptoms among >2000 French participants of the Asbestos-Related Diseases Cohort (ARDCO), 6 years after their inclusion, to identify the risk factors associated with those anxious and depressive symptoms and to evaluate the impact of the asbestos-risk perception. Methods: The ARDCO was constituted in four regions of France between October 2003 and December 2005, by including former asbestos workers. Between 2011 and 2012, participants of the ARDCO program were invited to undergo another chest CT scan 6 years after the previous scan. Participants were asked to complete questionnaires including asbestos exposure assessment, Hospital Anxiety and Depression Scale (HADS), asbestos-risk perception and self-perception of asbestos-related diseases. Results: Among the 2225 participants, 2210 fully completed questionnaires were collected and analyzed. The prevalence of symptoms of probable anxiety and probable depression was 19.7% and 9.9%, respectively. The risk of anxious and depressive symptoms was independently associated with self-perception of the intensity of asbestos exposure, asbestos-risk perception and self-perception of asbestos-related diseases. Conclusion: The results obtained in this large study confirm that previously asbestos-exposed subjects are likely to develop anxious and depressive symptoms. Finally, implications related to the prevention of anxiety and depression among asbestos-exposed workers is discussed. [ABSTRACT FROM AUTHOR]

The negative binomial distribution is adopted for analyzing asbestos fiber counts so as to account for both the sampling errors in capturing only a finite number of fibers and the inevitable human variation in identifying and counting sampled fibers. A simple approximation to this distribution is developed for the derivation of quantiles and approximate confidence limits. The success of the approximation depends critically on the use of Stirling's expansion to sufficient order, on exact normalization of the approximating distribution, on reasonable perturbation of quantities from the normal distribution, and on accurately approximating sums by inverse-trapezoidal integration. Accuracy of the approximation developed is checked through simulation and also by comparison to traditional approximate confidence intervals in the specific case that the negative binomial distribution approaches the Poisson distribution. The resulting statistics are shown to relate directly to early research into the accuracy of asbestos sampling and analysis. Uncertainty in estimating mean asbestos fiber concentrations given only a single count is derived. Decision limits (limits of detection) and detection limits are considered for controlling false-positive and false-negative detection assertions and are compared to traditional limits computed assuming normal distributions. [ABSTRACT FROM AUTHOR]

The duty to manage asbestos in non-domestic premises is described in the Control of Asbestos Regulations 2012. Health and Safety Executive (HSE) policy and guidance on asbestos in the built environment in Great Britain is that asbestos-containing materials (ACMs) that are in good condition and unlikely to be disturbed can be managed in place. Where ACMs are in poor condition or likely to be disturbed they should be repaired, encapsulated or, if necessary, removed. HSE and Government Office for Science hosted a stakeholder workshop to consider evidence on the management of ACMs in public buildings. Invitees attended from a range of backgrounds (including regulatory, government, academic, medical, public interest groups, and professional service providers). Participants considered the evidence, suggested nine evidence gap areas and ranked these according to preference in an anonymous vote. The top three suggested evidence gaps were: (i) the comparative risks of managing ACMs in place versus removal; (ii) improved measurement techniques at lower fibre concentrations; and (iii) building the evidence base on the effectiveness of asbestos management and safe removal. HSE will use the workshop outputs to inform its research planning. It is anticipated that a number of initiatives for shared research will be explored. [ABSTRACT FROM AUTHOR]

Asbestos and non-asbestos containing brake products are currently used in low- and middle-income countries like Colombia. Because brake products are distributed detached from their supports, they require manipulation before installation, which release fibers and expose workers. Previous studies of our research group have documented exposures in excess of the widely accepted 0.1 f/cm³ exposure guideline. The aim of this study is to identify factors associated with non-compliance of the 8-h time weighted average (TWA) 0.1 f/cm³ asbestos occupational limit among brake mechanics (i.e. riveters). Eighteen brake repair shops (BRS) located in Bogotá (Colombia) were sampled during 3 to 6 consecutive days for the entire work-shift. Personal and short-term personal samples were collected following NIOSH methods 7400 and 7402. Longitudinal based logistic regression models were used to determine the association between the odds of exceeding the 8-h TWA 0.1 f/cm³ asbestos occupational limit and variables such as type of tasks performed by workers, workload (number of products manipulated daily), years of experience as riveters, and shop characteristics. These models can be used to estimate the odds of being currently or historically overexposed when sampling data do not exist. Since the information required to run the models can vary for both retrospective and current asbestos occupational exposure studies, three models were constructed with different information requirements. The first model evaluated the association between the odds of non-compliance with variables related to the workload, the second model evaluated the association between the odds of non-compliance with variables related to the manipulation tasks, and the third model evaluated the association between the odds of non-compliance with variables related with both the type of tasks performed by workers and the workload. Variables associated with the odds of non-compliance included conducting at least one manipulation activity with beveling and grinding of asbestos and non-asbestos containing brake products during the work shift, the location of the worker in the shop during non-manipulation activities, cleaning activities of the manipulation area, the years of experience working as riveters, and the number of asbestos and non-asbestos containing brake products manipulated daily. These models could be useful for current and retrospective occupational studies, in determining the odds of non-compliance of the asbestos occupational limit among brake mechanics. [ABSTRACT FROM AUTHOR]

Objective: The use of measurement data in occupational exposure assessment allows more quantitative analyses of possible exposure-response relations. We describe a quantitative exposure assessment approach for five lung carcinogens (i.e. asbestos, chromium-VI, nickel, polycyclic aromatic hydrocarbons (by its proxy benzo(a)pyrene (BaP)) and respirable crystalline silica). A quantitative job-exposure matrix (JEM) was developed based on statistical modeling of large quantities of personal measurements. Methods: Empirical linear models were developed using personal occupational exposure measurements (n = 102 306) from Europe and Canada, as well as auxiliary information like job (industry), year of sampling, region, an a priori exposure rating of each job (none, low, and high exposed), sampling and analytical methods, and sampling duration. The model outcomes were used to create a JEM with a quantitative estimate of the level of exposure by job, year, andregion. Results: Decreasing time trends were observed for all agents between the 1970s and 2009, ranging from -1.2% per year for personal BaP and nickel exposures to -10.7% for asbestos (in the time period before an asbestos ban was implemented). Regional differences in exposure concentrations (adjusted for measured jobs, years of measurement, and sampling method and duration) varied by agent, ranging from a factor 3.3 for chromium-VI up to a factor 10.5 for asbestos. Conclusion: We estimated time-, job-, and region-specific exposure levels for four (asbestos, chromium-VI, nickel, and RCS) out of five considered lung carcinogens. Through statistical modeling of large amounts of personal occupational exposure measurement data we were able to derive a quantitative JEM to be used in community-based studies. [ABSTRACT FROM AUTHOR]