Evaluation of take home (para-occupational) exposure to asbestos and disease: a review of the literature

An evaluation of trends for mesothelioma mortality in American women: Addressing the content of a recent Morbidity and Mortality Weekly Report (MMWR)

Mesothelioma is a fatal disease that has historically been associated with exposure to airborne asbestos. Because occupational asbestos exposures dropped dramatically in the late 1960s and early 1970s, far fewer cases of mesothelioma today are due to these fibers but, instead, are usually a result of the aging process or genetic predisposition. In May of 2022, a Morbidity and Mortality Weekly Report (MMWR) was issued by the Centers for Disease Control and Prevention (CDC) regarding malignant mesothelioma incidence in women from 1999 to 2020. While this MMWR alerted citizens to the continued presence of the disease, after reading this article one might have thought that the CDC was suggesting that the disease was increasing in women due to asbestos exposures (which it is not). In the present analysis, we investigate several factors related to the interpretation of epidemiological data for mesothelioma, including the role of asbestos as a risk factor over time. The authors conducted a review of the scientific community's understanding of mesothelioma incidence and asbestos exposures amongst women, as well as an investigation of the methods and references in the MMWR article. Although various articles have recently discussed the incidence of both peritoneal and pleural mesothelioma in women, it is fortunate that the age-adjusted rates for mesothelioma have remained flat (neither increased nor decreased significantly) in women for the past 50 years. Incredibly few women in the U. S. have had appreciable cumulative exposures to any type of asbestos (chrysotile, amosite, or crocidolite) in the workplace or from the ambient environment, especially since about 1965-1970. In this paper, we highlight six factors that should be considered when evaluating the incidence of mesothelioma amongst American women in the current era. Without sufficient consideration of these factors, improper conclusions have been drawn over the past several years.

The aftermath of asbestos prohibition in industry and its association with malignant mesothelioma in the south of Iran: An enduring predicament yet to be resolved

Purpose

Malignant Mesothelioma (MM) is a rare malignancy of the serosa membranes with a high mortality rate and long latent period. The relationship between a group of mineral fibers known as asbestos and mesothelioma is now well accepted in which people can be exposed to these fibers by various means during their lifetime and has been its usage has banned in many countries, such as Iran, which announced its gradual elimination from 1999 over a period of 7 years by using safe substitutes. However, the mineral particles are able to sustain itself in the environment, air, water, and soil and on the other hand, symptoms may take up to half a century to develop in exposed individuals. Also, there remains a shortage of comprehensive investigation on the effects of asbestos exposure within the familial context (household or domestic exposure) or on individuals residing in proximity to asbestos mines or factories (environmental exposure). Based on the high number of MM cases in Iran, and also our hypothesis that residuals of asbestos in the environment and petroleum products may be the etiological factor for MM, we conducted this study to evaluate the clinic epidemiological features of MM in the south of Iran its relation to possible asbestos exposure.

Methods

In this study, we analyzed the demographic features and occupations of confirmed cases of MM in Shiraz, southern Iran along with the follow-up of the patients' disease from 2008 to 2018, while also comparing the features of our patients with a control group compromising of 105 non-MM patients.

Results

Among the 35 confirmed cases of MM, with an average age of 61 years, 9 (25.7%) were female, and 26 (74.3%) were male. During our assessment, 12 patients had already died, with a mean time of 11.26 months post-diagnosis. Our findings revealed a higher prevalence of MM among housekeepers and employees of oil companies. In comparison to the control group, individuals with occupational exposure and those residing near refinery locations were at a heightened risk of developing MM. However, based on regression analysis, only occupations associated with refineries exhibited a significant correlation with MM (p = 0.028; OR: 14.602; 95% CI: 1.328-160.499).

Conclusion

Both occupational and para-occupational exposure demonstrated a significant correlation with MM, whereas our regression analysis did not affirm geographical and environmental factors as contributors to MM. Despite the industry's prohibition of direct asbestos usage, the persistent existence of asbestos particles in the environment for decades, coupled with the long latency period of MM, warrants further investigation. Health authorities and policymakers should recognize this potential hazard, prompting an enhancement of early detection within at-risk groups.

Use of agent-based modeling to analyze potential non-occupational exposures to asbestos of the general population of Sibaté (Colombia)

Previous studies conducted in the municipality of Sibaté (Colombia) have revealed alarming findings regarding asbestos exposure in the region, as it is the site of the country's first mesothelioma cluster. Non-occupational asbestos exposure events were identified in this population, and the young age of the mesothelioma cases at the time of diagnosis suggests that asbestos exposure occurred during their childhood. The creation of landfilled zones in the 1980s and 1990s, utilizing friable asbestos among other disposed materials, may have been a significant asbestos exposure event contributing to the elevated number of mesothelioma cases. The objective of this study was to model various historical exposure scenarios related to the creation and interaction of the population with asbestos-contaminated landfilled zones, in light of the absence of asbestos monitoring in the region. The models utilized a multi-agent simulation process, focusing on a 10-year period (1986-1995). Various relevant variables were incorporated into the modeling process, including, for example, the number of children playing in the landfilled zones and the percentage of children carrying asbestos fibers on their clothes to their homes. A range of values for input data for the models were utilized, spanning from very conservative numbers to exposure-promoting values. The average number of exposed individuals estimated over 750 simulation runs, considering all scenarios, was 571, with a range between 31 and 3800 exposed individuals. The use of multi-agent simulation models can assist the understanding of past asbestos exposure events, especially when there is a lack of environmental surveillance data.

Children's health affected by parent's behavioral characteristics: a review

Exposure of an individual to occupational and environmental risk factors for a certain disease affects them and their family. Children are highly vulnerable in this setting because they are family-dependent. This review discusses diseases that occur in children according to the occupational and behavioral characteristics of their parents. Toxic agents in the home environment can affect children's health. Maternal exposure to substances during pregnancy may directly affect fetal outcomes. The Industrial Accident Compensation Insurance Act in Korea was amended in 2023 to compensate for children's adverse health effects due to their parents' occupational risks. The long working hours and smoking behaviors of parents and toxic materials in the home environment are highlighted. To control for the diverse factors affecting children's health in medical research, this review introduces directed acyclic graphs. Pediatric, occupational, and environmental medicine must collaborate to prevent childhood diseases related to environmental factors.

Occupational exposure to asbestos in the steel industry (1972-2006)

BACKGROUND

Historically, the use of asbestos in steelmaking has been limited to a few applications. Due to its physical and chemical properties, asbestos was not necessary or suitable for most purposes in a steel mill. The few applications where asbestos were used (i.e., certain gaskets, brakes, protective cloth, refractory materials, insulation materials, and hot top products) were replaced by alternative materials as they became available.

OBJECTIVE

We discuss historical uses of asbestos in steel manufacturing and the associated airborne asbestos concentrations collected at sixteen U. S. Steel facilities between 1972 and 2006.

METHODS

A total of 495 personal airborne asbestos samples from the U. S. Steel industrial hygiene records were analyzed across four time periods corresponding to changes in the OSHA permissible exposure limit (PEL) for asbestos. 68% of the samples (n = 337) were considered representative of an employee's workday. The remaining samples (n = 158) represented task samples. Samples were grouped by facility, department, and job category within the four time periods.

RESULTS

The average fiber concentrations measured for each facility and department over time were below the contemporaneous OSHA PEL. The mean representative workday asbestos air concentration from 1972 and 1975 was 1.09 f/cc. The mean representative workday concentration decreased to 0.13 f/cc between 1976 and 1985, then decreased again to 0.02 f/cc between 1986 and 1993 and 0.03 f/cc between 1994 and 2006. For task samples, the mean air concentration from 1972 to 1975 was 3.29 f/cc. The mean task sample concentration decreased to 0.48 f/cc between 1976 and 1985, then decreased again to 0.01 f/cc between 1986 and 1993 and 0.03 f/cc between 1994 and 2006. Only eleven out of the 495 samples (2.2%), for both task and representative workday samples, were in exceedance of the contemporaneous PEL(as an 8-hour TWA), ten of which occurred prior to 1978. Eight of these eleven PEL exceeding samples were task samples. Of the remaining three representative workday samples, two had unknown sampling times.

IMPACT

This paper presents an analysis of all the available personal sampling data for airborne asbestos across 16 facilities of the U. S. Steel Corporation between 1972 and 2006. This dataset has previously never been publicly shared or analyzed. It represents one of the more complete industrial hygiene datasets from a corporation to be presented in a scientific journal and, due to the similarities in the processes at each mill, it should reflect analogous exposures throughout the steelmaking industry in the United States. One of the benefits of presenting these data is that it also provides insight into where asbestos-containing materials (ACMs) were used in the steel making process. This is just one example of a large firm that released information that had previously remained in file cabinets for decades. We believe that another benefit of publishing this paper is that it may encourage the largest firms in industry to assemble and analyze their industrial hygiene data to benefit the occupational hygiene, medical, and epidemiology communities. This can support future epidemiology studies and improve the design of future industrial hygiene programs.

Vaping, Environmental Toxicants Exposure, and Lung Cancer Risk

Lung cancer (LC) is the second-most prevalent tumor worldwide. According to the most recent GLOBOCAN data, over 2.2 million LC cases were reported in 2020, with an estimated new death incident of 1,796,144 lung cancer cases. Genetic, lifestyle, and environmental exposure play an important role as risk factors for LC. E-cigarette, or vaping, products (EVPs) use has been dramatically increasing world-wide. There is growing concern that EVPs consumption may increase the risk of LC because EVPs contain several proven carcinogenic compounds. However, the relationship between EVPs and LC is not well established. E-cigarette contains nicotine derivatives (e.g., nitrosnornicotine, nitrosamine ketone), heavy metals (including organometal compounds), polycyclic aromatic hydrocarbons, and flavorings (aldehydes and complex organics). Several environmental toxicants have been proven to contribute to LC. Proven and plausible environmental carcinogens could be physical (ionizing and non-ionizing radiation), chemicals (such as asbestos, formaldehyde, and dioxins), and heavy metals (such as cobalt, arsenic, cadmium, chromium, and nickel). Air pollution, especially particulate matter (PM) emitted from vehicles and industrial exhausts, is linked with LC. Although extensive environmental exposure prevention policies and smoking reduction strategies have been adopted globally, the dangers remain. Combined, both EVPs and toxic environmental exposures may demonstrate significant synergistic oncogenicity. This review aims to analyze the current publications on the importance of the relationship between EVPs consumption and environmental toxicants in the pathogenesis of LC.

Para-occupational exposure to chemical substances: a systematic review

Today, many health problems related to work have overshadowed workers and their families. In the meantime, chemicals are among the risk factors that have created many problems due to para-occupational exposure. In para-occupational exposures, family members are exposed to work pollutants transferred to the home environment. This study was conducted to investigate para-occupational exposure to chemicals. To conduct this systematic review, databases such as "Web of Science", "Google Scholar", "Scopus", and "SID" were used. Relevant articles in these databases were extracted by searching keywords such as "take-home exposure", "para-occupational exposure", and "chemicals" from 2000 to 2022. To extract the required data, all parts of the articles were reviewed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA 2020). Among the 44 identified articles, 23 were selected as final articles, of which 10 were related to agriculture workers and their families, and 13 were related to other occupations. These studies mainly investigated para-occupational exposure to pesticides (14 studies) and metals (four studies). Also, contaminated work clothes, the washing place of contaminated clothes, and storage of working clothes, equipment, and chemicals were proposed as the main routes of contamination transmission. As a result of these para-occupational exposures, problems like neuro-behavioral disorders in children, end-stage renal disease, black gingival borders, and autism spectrum disorder were created or aggravated. Limiting the transmission routes and taking measures such as training and providing facilities like devoting places for washing and storing clothes in the workplaces can decrease this type of exposure.

Reconstructing historical exposure to asbestos: the validation of 'educated guesses'

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.

Modeling Clothing as a Vector for Transporting Airborne Particles and Pathogens across Indoor Microenvironments

Evidence suggests that human exposure to airborne particles and associated contaminants, including respiratory pathogens, can persist beyond a single microenvironment. By accumulating such contaminants from air, clothing may function as a transport vector and source of "secondary exposure". To investigate this function, a novel microenvironmental exposure modeling framework (ABICAM) was developed. This framework was applied to a para-occupational exposure scenario involving the deposition of viable SARS-CoV-2 in respiratory particles (0.5-20 μm) from a primary source onto clothing in a nonhealthcare setting and subsequent resuspension and secondary exposure in a car and home. Variability was assessed through Monte Carlo simulations. The total volume of infectious particles on the occupant's clothing immediately after work was 4800 μm3 (5th-95th percentiles: 870-32 000 μm3). This value was 61% (5-95%: 17-300%) of the occupant's primary inhalation exposure in the workplace while unmasked. By arrival at the occupant's home after a car commute, relatively rapid viral inactivation on cotton clothing had reduced the infectious volume on clothing by 80% (5-95%: 26-99%). Secondary inhalation exposure (after work) was low in the absence of close proximity and physical contact with contaminated clothing. In comparison, the average primary inhalation exposure in the workplace was higher by about 2-3 orders of magnitude. It remains theoretically possible that resuspension and physical contact with contaminated clothing can occasionally transmit SARS-CoV-2 between humans.

Asbestos in High-Risk Communities: Public Health Implications

Asbestos-related diseases (ARDs)-mesothelioma, lung cancer, and asbestosis-are well known as occupational diseases. As industrial asbestos use is eliminated, ARDs within the general community from para-occupational, environmental, and natural exposures are more prominent. ARD clusters have been studied in communities including Broni, Italy; Libby, Montana; Wittenoom, Western Australia; Karain, Turkey; Ambler, Pennsylvania; and elsewhere. Community ARDs pose specific public health issues and challenges. Community exposure results in higher proportions of mesothelioma in women and a younger age distribution than occupational exposures. Exposure amount, age at exposure, fiber type, and genetic predisposition influence ARD expression; vulnerable groups include those with social and behavioral risk, exposure to extreme events, and genetic predispositions. To address community exposure, regulations should address all carcinogenic elongated mineral fibers. Banning asbestos mining, use, and importation will not reduce risks from asbestos already in place. Residents of high-risk communities are characteristically exposed through several pathways differing among communities. Administrative responsibility for controlling environmental exposures is more diffuse than for workplaces, complicated by diverse community attitudes to risk and prevention and legal complexity. The National Mesothelioma Registries help track the identification of communities at risk. High-risk communities need enhanced services for screening, diagnosis, treatment, and social and psychological support, including for retired asbestos workers. Legal settlements could help fund community programs. A focus on prevention, public health programs, particularization to specific community needs, and participation is recommended.

Lung Asbestos Fibre Burden and Pleural Mesothelioma in Women with Non-occupational Exposure

BACKGROUND

Malignant pleural mesothelioma (MPM) due to environmental and familial (domestic) asbestos exposure is well recognized. However, information on cumulative asbestos dose in subjects affected by MPM is limited.

OBJECTIVES

To evaluate the residual lung asbestos fibre and asbestos body burden in women with MPM with past environmental and/or familial asbestos exposure.

METHODS

We collected lung samples from autopsies regarding 15 non-occupationally asbestos-exposed MPM cases, divided in three groups: (i) familial exposure from the Fincantieri shipyards in Monfalcone (No. 7), (ii) environmental and familial asbestos exposure from the asbestos-cement plant Fibronit in Broni (No. 6), and (iii) environmental exposure from the Fibronit plant (No. 2). Asbestos body (AB) and fibres (AF) per gram of dry lung tissue were counted by optical and scanning electron microscopy, respectively, and expressed as geometric means and standard deviations (GM, GSD).

RESULTS

GM/GSD of AB counts were 6123/9.6 (Group 1), 13 800/10.4 (Group 2), and 8400/1.1 (Group 3); GM/GSD of AF were 0.6/2.1 (Group 1), 7.9/2.1 (Group 2), and 6.0/2.3 (Group 3) million. Pleural plaques were observed in 12 cases.

CONCLUSIONS

Exclusive familial exposure to asbestos determined cumulative doses close to those observed in moderate occupational exposure circumstances. Our results also suggest that combined environmental and familial exposures may cause unexpectedly high cumulative fibre doses.

Inherited Genetic Mutations and Polymorphisms in Malignant Mesothelioma: A Comprehensive Review

Malignant mesothelioma (MM) is mainly caused by air-born asbestos but genetic susceptibility is also suspected to be a risk factor. Recent studies suggest an increasing number of candidate genes that may predispose to MM besides the well-characterized BRCA1-associated protein-1 gene. The aim of this review is to summarize the most important studies on germline mutations for MM. A total of 860 publications were retrieved from Scopus, PubMed and Web of Science, of which 81 met the inclusion criteria and were consider for this review. More than 50% of the genes that are reported to predispose to MM are involved in DNA repair mechanisms, and the majority of them have a role in the homologous recombination pathway. Genetic alterations in tumor suppressor genes involved in chromatin, transcription and hypoxia regulation have also been described. Furthermore, we identified several single nucleotide polymorphisms (SNPs) that may promote MM tumorigenesis as a result of an asbestos-gene interaction, including SNPs in DNA repair, carcinogen detoxification and other genes previously associated with other malignancies. The identification of inherited mutations for MM and an understanding of the underlying pathways may allow early detection and prevention of malignancies in high-risk individuals and pave the way for targeted therapies.

Analyzing biological and molecular characteristics and genomic damage induced by exposure to asbestos

Asbestos is one of the most important occupational carcinogens. Currently, about 125 million people worldwide are exposed to asbestos in the workplace. According to global estimates, at least 107,000 people die each year from lung cancer, mesothelioma, and asbestosis as a result of occupational exposure to asbestos. The high pathogenicity of this material is currently known, being associated with the development of pulmonary diseases, of which lung cancer is the main cause of death due to exposure to this mineral. Pulmonary diseases related to asbestos are a common clinical problem and a major health concern worldwide. Extensive research has identified many important pathogenic mechanisms; however, the precise molecular mechanisms involved, and the generated genomic damage that lead to the development of these diseases, are not completely understood. The modes of action that underlie this type of disease seem to differ depending on the type of fiber, lung clearance, and genetics. This evidences the need to increase our knowledge about these effects on human health. This review focuses on the characteristics of asbestos and the cellular and genomic damage generated in humans via exposure.

Clothing-Mediated Exposures to Chemicals and Particles

A growing body of evidence identifies clothing as an important mediator of human exposure to chemicals and particles, which may have public health significance. This paper reviews and critically assesses the state of knowledge regarding how clothing, during wear, influences exposure to molecular chemicals, abiotic particles, and biotic particles, including microbes and allergens. The underlying processes that govern the acquisition, retention, and transmission of clothing-associated contaminants and the consequences of these for subsequent exposures are explored. Chemicals of concern have been identified in clothing, including byproducts of their manufacture and chemicals that adhere to clothing during use and care. Analogously, clothing acts as a reservoir for biotic and abiotic particles acquired from occupational and environmental sources. Evidence suggests that while clothing can be protective by acting as a physical or chemical barrier, clothing-mediated exposures can be substantial in certain circumstances and may have adverse health consequences. This complex process is influenced by the type and history of the clothing; the nature of the contaminant; and by wear, care, and storage practices. Future research efforts are warranted to better quantify, predict, and control clothing-related exposures.

Interstitial Lung Diseases in Developing Countries

More than 100 different conditions are grouped under the term interstitial lung disease (ILD). A diagnosis of an ILD primarily relies on a combination of clinical, radiological, and pathological criteria, which should be evaluated by a multidisciplinary team of specialists. Multiple factors, such as environmental and occupational exposures, infections, drugs, radiation, and genetic predisposition have been implicated in the pathogenesis of these conditions. Asbestosis and other pneumoconiosis, hypersensitivity pneumonitis (HP), chronic beryllium disease, and smoking-related ILD are specifically linked to inhalational exposure of environmental agents. The recent Global Burden of Disease Study reported that ILD rank 40th in relation to global years of life lost in 2013, which represents an increase of 86% compared to 1990. Idiopathic pulmonary fibrosis (IPF) is the prototype of fibrotic ILD. A recent study from the United States reported that the incidence and prevalence of IPF are 14.6 per 100,000 person-years and 58.7 per 100,000 persons, respectively. These data suggests that, in large populated areas such as Brazil, Russia, India, and China (the BRIC region), there may be approximately 2 million people living with IPF. However, studies from South America found much lower rates (0.4–1.2 cases per 100,000 per year). Limited access to high-resolution computed tomography and spirometry or to multidisciplinary teams for accurate diagnosis and optimal treatment are common challenges to the management of ILD in developing countries.

Indoor release of asbestiform fibers from naturally contaminated water and related health risk

This study investigates the occurrence of airborne asbestiform fibers released in indoor ambient due to the use of asbestos naturally contaminated water. Some experiments employed a laboratory physical model using an ultrasonic humidifier charged with contaminated groundwater. Other experiments were carried out at full scale to assess the release of asbestiform fibers during showering. Obtained results show that the concentration of the airborne asbestiform fibers released in the bathroom during showering is higher than the limit value set by the European and Italian Regulations, while the concentration of fibers released by the humidifier is much lower. However, it is noteworthy that the use of the humidifier at high exposure time results in similar health risk. Strong correlations were found between the concentration of the airborne asbestiform fibers and a novel surrogate parameter (i.e. the exposure-specific-water-consumption). These correlations can be used to monitor the asbestiform fibers concentration at varying operating conditions and therefore, to control the resulting health risk.

Recent Scientific Evidence Regarding Asbestos Use and Health Consequences of Asbestos Exposure

To justify the continuous use of two million tons of asbestos every year, it has been argued that a safe/controlled use can be achieved. The aim of this review was to identify recent scientific studies that present empirical evidence of: 1) health consequences resulting from past asbestos exposures and 2) current asbestos exposures resulting from asbestos use. Articles with evidence that could support or reject the safe/controlled use argument were also identified. A total of 155 articles were included in the review, and 87 % showed adverse asbestos health consequences or high asbestos exposures. Regarding the safe/controlled use, 44 articles were identified, and 82 % had evidence suggesting that the safe/controlled use is not being achieved. A large percentage of articles with evidence that support the safe/controlled use argument have a conflict of interest declared. Most of the evidence was developed in high-income countries and in countries that have already banned asbestos.

Evaluation of take-home exposure to asbestos from handling asbestos-contaminated worker clothing following the abrasive sawing of cement pipe

Although industrial uses of asbestos have declined since the 1970s, in recent years there has been a renewed interest in para-occupational ("take-home") exposure to these fibers. The aim of this study was to quantify the release of asbestos fibers, if any, during the shaking out of crocidolite- and chrysotile-contaminated clothing in a simulated at-home setting. An exposure study was conducted in which personal and area air samples were collected during the handling (i.e. shake-out) of work clothing (shirt and pants) previously worn by an operator who had cut asbestos-containing cement pipe. During eight "loading" events, the operator cut a historically representative asbestos-containing cement pipe (10% crocidolite and 25% chrysotile) using a powered abrasive saw. Subsequently, 30-minute air samples were collected during four "shake-out" events, each of which consisted of the handling of two complete sets of contaminated work clothes. Samples were analyzed in accordance with NIOSH methods 7400 and 7402. The mean phase contrast microscopy equivalent (PCME) airborne concentrations were 0.52 f/cc (SD = 0.34 f/cc) for total asbestos fibers, 0.36 f/cc (SD = 0.26 f/cc) for chrysotile and 0.17 f/cc (SD = 0.096 f/cc) for crocidolite. Based on likely estimates of the frequency of laundering activities, and assuming that the dusty clothing (1) is not blown off in the occupational setting using compressed air and (2) is not shaken out before entering the home, a family member handling the clothing could potentially have a lifetime cumulative exposure to chrysotile and crocidolite of approximately 0.20 f/cc-year and 0.096 f/cc-year, respectively.

The economic burden of lung cancer and mesothelioma due to occupational and para-occupational asbestos exposure

OBJECTIVES

To estimate the economic burden of lung cancer and mesothelioma due to occupational and para-occupational asbestos exposure in Canada.

METHODS

We estimate the lifetime cost of newly diagnosed lung cancer and mesothelioma cases associated with occupational and para-occupational asbestos exposure for calendar year 2011 based on the societal perspective. The key cost components considered are healthcare costs, productivity and output costs, and quality of life costs.

RESULTS

There were 427 cases of newly diagnosed mesothelioma cases and 1904 lung cancer cases attributable to asbestos exposure in 2011 for a total of 2331 cases. Our estimate of the economic burden is $C831 million in direct and indirect costs for newly identified cases of mesothelioma and lung cancer and $C1.5 billion in quality of life costs based on a value of $C100 000 per quality-adjusted life year. This amounts to $C356 429 and $C652 369 per case, respectively.

CONCLUSIONS

The economic burden of lung cancer and mesothelioma associated with occupational and para-occupational asbestos exposure is substantial. The estimate identified is for 2331 newly diagnosed, occupational and para-occupational exposure cases in 2011, so it is only a portion of the burden of existing cases in that year. Our findings provide important information for policy decision makers for priority setting, in particular the merits of banning the mining of asbestos and use of products containing asbestos in countries where they are still allowed and also the merits of asbestos removal in older buildings with asbestos insulation.

Environmental asbestos exposure and risk of mesothelioma

Mesothelioma is commonly considered an occupational disease occurring as a result of asbestos exposure in the workplace. Several avenues for environmental asbestos exposures have been described and may be associated with asbestos related disease, including mesothelioma. Worker take-home asbestos, or para-occupational exposure, has been well documented and is the most commonly reported pathway for asbestos exposure among mesothelioma cases that do not have history of occupational asbestos exposure. Observational studies have evaluated several communities with elevated mesothelioma incidence and environmental exposures attributed to local asbestos-related industries. Potential, but uncertain, mesothelioma risk also may be associated with general population asbestos exposure through contact with asbestos-containing commercial products, particularly housing materials that can be easily disturbed through normal activity. Finally, studies have described elevated mesothelioma incidence in several areas where populations are exposed to naturally occurring asbestos materials. These various environmental asbestos exposure pathways are poorly understood, and further studies should be pursued to evaluate their respective importance for population mesothelioma risk.

Geographic dimensions of a health network dedicated to occupational and work related diseases

Background

Although introduced nearly 40 years ago, Geographic Information Systems (GISs) have never been used to study Occupational Health information regarding the different types, scale or sources of data. The geographic distribution of occupational diseases and underlying work activities were always analyzed independently. Our aim was to consider the French Network of Occupational Disease (OD) clinics, namely the “French National OD Surveillance and Prevention Network” (rnv3p) as a spatial object in order to describe its catchment.

Methods

We mapped rnv3p observations at the workplace level. We initially analyzed rnv3p capture with reference to its own data, then to the underlying workforce (INSEE “Employment Areas”), and finally compared its capture of one emblematic occupational disease (mesothelioma) to an external dataset provided by a surveillance system thought to be exhaustive (PNSM).

Results

While the whole country is covered by the network, the density of observations decreases with increase in the distance from the 31 OD clinics (located within the main French cities). Taking into account the underlying workforce, we show that the probability to capture and investigation of OD (assessed by rates of OD per 10,000 workers) also presents large discrepancies between OD clinics. This capture rate might also show differences according to the disease, as exemplified by mesothelioma.

Conclusion

The geographic approach to this network, enhanced by the possibilities provided by the GIS tool, allow a better understanding of the coverage of this network at a national level, as well as the visualization of capture rates for all OD clinics. Highlighting geographic and thematic shading zones bring new perspectives to the analysis of occupational health data, and should improve occupational health vigilance and surveillance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12942-016-0063-7) contains supplementary material, which is available to authorized users.

Airborne asbestos take-home exposures during handling of chrysotile-contaminated clothing following simulated full shift workplace exposures

The potential for para-occupational, domestic, or take-home exposures from asbestos-contaminated work clothing has been acknowledged for decades, but historically has not been quantitatively well characterized. A simulation study was performed to measure airborne chrysotile concentrations associated with laundering of contaminated clothing worn during a full shift work day. Work clothing fitted onto mannequins was exposed for 6.5 h to an airborne concentration of 11.4 f/cc (PCME) of chrysotile asbestos, and was subsequently handled and shaken. Mean 5-min and 15-min concentrations during active clothes handling and shake-out were 3.2 f/cc and 2.9 f/cc, respectively (PCME). Mean airborne PCME concentrations decreased by 55% 15 min after clothes handling ceased, and by 85% after 30 min. PCM concentrations during clothes handling were 11-47% greater than PCME concentrations. Consistent with previously published data, daily mean 8-h TWA airborne concentrations for clothes-handling activity were approximately 1.0% of workplace concentrations. Similarly, weekly 40-h TWAs for clothes handling were approximately 0.20% of workplace concentrations. Estimated take-home cumulative exposure estimates for weekly clothes handling over 25-year working durations were below 1 f/cc-year for handling work clothes contaminated in an occupational environment with full shift airborne chrysotile concentrations of up to 9 f/cc (8-h TWA).

Primary Peritoneal Mesothelioma Resulting in Small Bowel Obstruction: A Case Report and Review of Literature

BACKGROUND

Peritoneal mesothelioma is a rare malignancy that affects the serosal surfaces of the peritoneum. The peritoneum is the second most common site of mesothelium affected following the pleura. The aggressive nature and vague presentation pose many obstacles in not only diagnosis but also the treatment of patients with this disease.

CASE REPORT

We present a case of a 76-year-old woman who presented with small bowel obstruction secondary to carcinomatosis secondary to primary peritoneal mesothelioma. The patient had multiple risk factors with asbestos exposure and prior therapeutic radiation.

CONCLUSIONS

We discuss the highly varied and elusive presentation of peritoneal mesothelioma. Cumulative asbestos exposure, either directly or indirectly, remains the leading cause of mesothelioma. However, there are other non-asbestos etiologies. Small bowel obstruction often is a late-presenting symptom of widespread tumor burden. A concise review of the current diagnostic and surgical treatment of primary peritoneal mesothelioma demonstrates that early diagnosis and implementation remains vital.

Changing pattern in malignant mesothelioma survival

Survival for mesothelioma has been shown to be poor, with marginal improvement over time. Recent advances in the understanding of pathophysiology and treatment of mesothelioma may impact therapy to improve survival that may not be evident from available clinical trials that are often small and not randomized. Therapies may affect survival differently based on mesothelioma location (pleural vs peritoneal). Data are conflicting regarding the effect of asbestos exposure on mesothelioma location.

OBJECTIVES

We examined survival in a large cohort of mesothelioma subjects analyzed by tumor location and presence and mode of asbestos exposure.

METHODS

Data were analyzed from cases (n = 380) diagnosed with mesothelioma from 1992 to 2012. Cases were either drawn from treatment referrals, independent medical evaluation for medical legal purposes, or volunteers who were diagnosed with mesothelioma. Subjects completed an occupational medical questionnaire, personal interview with the examining physician, and physician review of the medical record.

RESULTS

This study reports better survival for mesothelioma than historical reports. Survival for peritoneal mesothelioma was longer than that for pleural mesothelioma (hazard ratio = 0.36, 95% confidence interval = 0.24-0.54, P < .001) after adjusting for gender and age at diagnosis. Non-occupational cases were more likely to be 1) diagnosed with peritoneal mesothelioma, 2) female, 3) exposed, and 4) diagnosed at a younger age and to have a 5) shorter latency compared to occupational cases (P < .001).

CONCLUSION

Peritoneal mesothelioma was more likely associated with non-occupational exposure, thus emphasizing the importance of exposure history in enhancing early diagnosis and treatment impact.

Parental occupational exposure and risk of childhood central nervous system tumors: a pooled analysis of case-control studies from Germany, France, and the UK

PURPOSE

To assess the risk of childhood central nervous system (CNS) tumors associated with parental occupational exposure to polycyclic aromatic hydrocarbons (PAH), diesel motor exhaust (DME), asbestos, crystalline silica, and metals, which are established carcinogens in adults.

METHODS

We pooled data from three population-based case-control studies from Germany, France, and the UK. Cases were children aged up to 15 years and diagnosed with CNS tumor, and controls were frequency-matched by age and sex. Socio-demographic data and parental occupation around conception/pregnancy and at diagnosis were collected using standardized interviews, face-to-face or by telephone. A general population job-exposure matrix was used to assign a level of exposure to each job. Logistic regression models were fitted to compute odds ratios and 95 % confidence intervals.

RESULTS

Our study included 1,361 cases of CNS tumors and 5,500 controls. Paternal exposure to PAH, asbestos, and metals around conception was associated with an increased moderate risk of CNS tumors, although statistically non-significant. The association with exposure to asbestos around conception and diagnosis was stronger when fathers were exposed to high levels. Paternal exposure to DME and silica, and maternal exposure to PAH, DME, asbestos, silica, and metals, were not associated with an increased risk of CNS tumors.

CONCLUSION

Our large pooled study showed weak evidence of a modest association between paternal occupational exposure to PAH and CNS tumor risk. Our findings need further exploration in the future studies.

Pulmonary fibrosis following household exposure to asbestos dust?

An 81-year-old woman was dying from histologically confirmed pulmonary fibrosis without having had any asbestos exposure in the workplace. The lung dust fibre analysis showed significantly increased "asbestos bodies" (AB) (2,640 AB per gram of wet lung tissue) and asbestos fibre concentrations (8,600,000 amphibole fibres of all lengths and 540,000 amphibole fibres with a length ≥5 μm per gram of dry lung tissue). Asbestos exposure was revealed to have occurred during household contact after 27 years of washing her husband's industrial clothing that had been contaminated by asbestos at his workplace in an asbestos textile factory. Household asbestos dust exposure as a risk or co-factor in the aetiology of the fatal pulmonary fibrosis is discussed.

Evaluation of take-home exposure and risk associated with the handling of clothing contaminated with chrysotile asbestos

The potential for para-occupational (or take-home) exposures from contaminated clothing has been recognized for the past 60 years. To better characterize the take-home asbestos exposure pathway, a study was performed to measure the relationship between airborne chrysotile concentrations in the workplace, the contamination of work clothing, and take-home exposures and risks. The study included air sampling during two activities: (1) contamination of work clothing by airborne chrysotile (i.e., loading the clothing), and (2) handling and shaking out of the clothes. The clothes were contaminated at three different target airborne chrysotile concentrations (0-0.1 fibers per cubic centimeter [f/cc], 1-2 f/cc, and 2-4 f/cc; two events each for 31-43 minutes; six events total). Arithmetic mean concentrations for the three target loading levels were 0.01 f/cc, 1.65 f/cc, and 2.84 f/cc (National Institute of Occupational Health and Safety [NIOSH] 7402). Following the loading events, six matched 30-minute clothes-handling and shake-out events were conducted, each including 15 minutes of active handling (15-minute means; 0.014-0.097 f/cc) and 15 additional minutes of no handling (30-minute means; 0.006-0.063 f/cc). Percentages of personal clothes-handling TWAs relative to clothes-loading TWAs were calculated for event pairs to characterize exposure potential during daily versus weekly clothes-handling activity. Airborne concentrations for the clothes handler were 0.2-1.4% (eight-hour TWA or daily ratio) and 0.03-0.27% (40-hour TWA or weekly ratio) of loading TWAs. Cumulative chrysotile doses for clothes handling at airborne concentrations tested were estimated to be consistent with lifetime cumulative chrysotile doses associated with ambient air exposure (range for take-home or ambient doses: 0.00044-0.105 f/cc year).

Traumatic implantation: a novel aetiology in the development of peritoneal mesothelioma

Peritoneal mesothelioma is a rare intra-abdominal malignancy. Its aetiology has been thought to be due to either inhalation or ingestion of asbestos particles. We present a case of peritoneal mesothelioma developing as a result of a novel third route and the inoculation of fibres into the peritoneal cavity by penetrating trauma and direct transport. This case report highlights the important long term consequences of penetrating abdominal trauma and the need for vigilance in undertaking peritoneal toilet.

Domestic asbestos exposure: a review of epidemiologic and exposure data

Inhalation of asbestos resulting from living with and handling the clothing of workers directly exposed to asbestos has been established as a possible contributor to disease. This review evaluates epidemiologic studies of asbestos-related disease or conditions (mesothelioma, lung cancer, and pleural and interstitial abnormalities) among domestically exposed individuals and exposure studies that provide either direct exposure measurements or surrogate measures of asbestos exposure. A meta-analysis of studies providing relative risk estimates (n = 12) of mesothelioma was performed, resulting in a summary relative risk estimate (SRRE) of 5.02 (95% confidence interval [CI]: 2.48-10.13). This SRRE pertains to persons domestically exposed via workers involved in occupations with a traditionally high risk of disease from exposure to asbestos (i.e., asbestos product manufacturing workers, insulators, shipyard workers, and asbestos miners). The epidemiologic studies also show an elevated risk of interstitial, but more likely pleural, abnormalities (n = 6), though only half accounted for confounding exposures. The studies are limited with regard to lung cancer (n = 2). Several exposure-related studies describe results from airborne samples collected within the home (n = 3), during laundering of contaminated clothing (n = 1) or in controlled exposure simulations (n = 5) of domestic exposures, the latter of which were generally associated with low-level chrysotile-exposed workers. Lung burden studies (n = 6) were also evaluated as a surrogate of exposure. In general, available results for domestic exposures are lower than the workers' exposures. Recent simulations of low-level chrysotile-exposed workers indicate asbestos levels commensurate with background concentrations in those exposed domestically.

Asbestos and the lung in the 21st century: an update

The asbestos-related disorders (ARDs) are currently of significant occupational and public health concern. Asbestos usage has been banned in most developed countries, but asbestos is still used in many developing countries and the number of cases of ARDs worldwide is rising. Many countries are now experiencing an epidemic of ARDs that is the legacy of occupational exposure in the 1960s-1980s because of the long latency period between asbestos exposure and manifestation of disease. It is likely that asbestos-related mortality and morbidity will continue to increase. Although the most feared complications of asbestos inhalation are the malignant conditions such as mesothelioma and lung cancer, asbestos inhalation more frequently results in benign conditions such as pleural plaques, diffuse pleural thickening, and asbestosis (pulmonary fibrosis due to asbestos exposure). Over recent years, there have been changes in the epidemiology of mesothelioma, in clinical management of ARDs and developments in new techniques for early detection of malignancy. This review provides an update on the respiratory manifestations of asbestos exposure and also considers advances in screening methods that may affect future management in the workplace.

Compensation for environmental asbestos-related diseases in South Africa: a neglected issue

Background

Environmentally acquired asbestos-related diseases (ARDs) are of concern globally. In South Africa, there is widespread contamination of the environment due to historical asbestos mining operations that were poorly regulated. Although the law makes provision for the compensation of occupationally acquired ARDs, compensation for environmentally acquired ARDs is only available through the Asbestos Relief Trust (ART) and Kgalagadi Relief Trust, both of which are administered by the ART. This study assessed ARDs and compensation outcomes of environmental claims submitted to the Trusts.

Methods

The personal details, medical diagnoses, and exposure information of all environmental claims considered by the Trusts from their inception in 2003 to April 2010 were used to calculate the numbers and proportions of ARDs and compensation awards.

Results

There were 146 environmental claimants of whom 35 (23.9%) had fibrotic pleural disease, 1 (0.7%) had lung cancer, and 77 (52.7%) had malignant mesothelioma. 53 (36.3%) claimants were compensated: 20 with fibrotic pleural disease and 33 with mesothelioma. Of the 93 (63.7%) claimants who were not compensated, 33 had no ARDs, 18 had fibrotic pleural disease, 1 had lung cancer, and 44 had mesothelioma. In addition to having ARDs, those that were compensated had qualifying domestic (33; 62.2%) or neighbourhood (20; 37.8%) exposures to asbestos. Most of the claimants who were not compensated had ARDs but their exposures did not meet the Trusts’ exposure criteria.

Conclusions

This study demonstrates the environmental impact of asbestos mining on the burden of ARDs. Mesothelioma was the most common disease diagnosed, but most cases were not compensated. This highlights that there is little redress for individuals with environmentally acquired ARDs in South Africa. To stop this ARD epidemic, there is a need for the rehabilitation of abandoned asbestos mines and the environment. These issues may not be unique to South Africa as many countries continue to mine and use asbestos.