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Journal of Toxicology and Environmental... 2011The cellular and molecular mechanisms of how asbestos fibers induce cancers and other diseases are not well understood. Both serpentine and amphibole asbestos fibers... (Review)
Review
The cellular and molecular mechanisms of how asbestos fibers induce cancers and other diseases are not well understood. Both serpentine and amphibole asbestos fibers have been shown to induce oxidative stress, inflammatory responses, cellular toxicity and tissue injuries, genetic changes, and epigenetic alterations in target cells in vitro and tissues in vivo. Most of these mechanisms are believe to be shared by both fiber-induced cancers and noncancerous diseases. This article summarizes the findings from existing literature with a focus on genetic changes, specifically, mutagenicity of asbestos fibers. Thus far, experimental evidence suggesting the involvement of mutagenesis in asbestos carcinogenicity is more convincing than asbestos-induced fibrotic diseases. The potential contributions of mutagenicity to asbestos-induced diseases, with an emphasis on carcinogenicity, are reviewed from five aspects: (1) whether there is a mutagenic mode of action (MOA) in fiber-induced carcinogenesis; (2) mutagenicity/carcinogenicity at low dose; (3) biological activities that contribute to mutagenicity and impact of target tissue/cell type; (4) health endpoints with or without mutagenicity as a key event; and finally, (5) determinant factors of toxicity in mutagenicity. At the end of this review, a consensus statement of what is known, what is believed to be factual but requires confirmation, and existing data gaps, as well as future research needs and directions, is provided.
Topics: Animals; Asbestos; Asbestosis; Carcinogens, Environmental; Chemical Phenomena; DNA Damage; Humans; Mineral Fibers; Mitosis; Mutation; Neoplasms; Pleural Diseases
PubMed: 21534089
DOI: 10.1080/10937404.2011.556051 -
Canadian Respiratory Journal 2016Patients with an asbestos-related mesothelioma may be legally entitled to financial compensation. In this context, a physician may be called upon to apportion the... (Review)
Review
Patients with an asbestos-related mesothelioma may be legally entitled to financial compensation. In this context, a physician may be called upon to apportion the contribution of an asbestos containing product or facility where there was asbestos exposure in the development of that individual's mesothelioma. This task is mathematically not simple. It is a complex function of each and the entire individual's above-background asbestos exposures. Factors to be considered for each of these exposures are the amount of exposure to mesotheliogenic fibers, each of the asbestos containing products' potency to cause mesothelioma, and the time period when the exposures occurred relative to when the mesothelioma was diagnosed. In this paper, the known factors related to asbestos-related mesothelioma risk are briefly reviewed and the software that is downloadable and fully functional in a Windows® environment is also provided. This software allows for rapid assessment of relative contributions and deals with the somewhat tedious mathematical calculations. With this software and a reasonable occupational history, if it is decided that the mesothelioma was due to above-background asbestos exposure, the contribution of an asbestos containing product or a time period of asbestos exposure can be apportioned.
Topics: Animals; Asbestos; Cost Allocation; Environmental Exposure; Humans; Lung Neoplasms; Mesothelioma; Software; Time Factors
PubMed: 27445546
DOI: 10.1155/2016/5340676 -
International Journal of Environmental... May 2016More than 40 years of evaluation have consistently confirmed the carcinogenicity of asbestos in all of its forms. This notwithstanding, according to recent figures, the... (Review)
Review
More than 40 years of evaluation have consistently confirmed the carcinogenicity of asbestos in all of its forms. This notwithstanding, according to recent figures, the annual world production of asbestos is approximatively 2,000,000 tons. Currently, about 90% of world asbestos comes from four countries: Russia, China, Brazil and Kazakhstan; and the wide use of asbestos worldwide represents a global threat. The purpose of this paper is to present a review of the asbestos health impact and to discuss the role of epidemiological investigations in countries where asbestos is still used. In these contexts, new, "local" studies can stimulate awareness of the size of the problem by public opinion and other stakeholders and provide important information on the circumstances of exposure, as well as local asbestos-related health impacts. This paper suggests an agenda for an international cooperation framework dedicated to foster a public health response to asbestos, including: new epidemiological studies for assessing the health impact of asbestos in specific contexts; socio-cultural and economic analyses for contributing to identifying stakeholders and to address both the local and global implications of asbestos diffusion; public awareness on the health and socio-economic impact of asbestos use and banning.
Topics: Asbestos; Brazil; China; Environmental Exposure; Humans; International Cooperation; Kazakhstan; Public Health; Russia
PubMed: 27187433
DOI: 10.3390/ijerph13050494 -
Journal of Toxicology and Environmental... 2011Although asbestos research has been ongoing for decades, this increased knowledge has not led to consensus in many areas of the field. Two such areas of controversy... (Review)
Review
Although asbestos research has been ongoing for decades, this increased knowledge has not led to consensus in many areas of the field. Two such areas of controversy include the specific definitions of asbestos, and limitations in understanding exposure-response relationships for various asbestos types and exposure levels and disease. This document reviews the current regulatory and mineralogical definitions and how variability in these definitions has led to difficulties in the discussion and comparison of both experimental laboratory and human epidemiological studies for asbestos. This review also examines the issues of exposure measurement in both animal and human studies, and discusses the impact of these issues on determination of cause for asbestos-related diseases. Limitations include the lack of detailed characterization and limited quantification of the fibers in most studies. Associated data gaps and research needs are also enumerated in this review.
Topics: Animals; Asbestos; Body Burden; Carcinogens, Environmental; Environmental Exposure; Government Regulation; Humans; Inhalation Exposure; Lung Neoplasms; Mesothelioma; Occupational Exposure; Particulate Matter; Risk; Terminology as Topic
PubMed: 21534084
DOI: 10.1080/10937404.2011.556045 -
La Medicina Del Lavoro Dec 2023Quantification of asbestos fibers has been mainly performed in the lung but rarely in other organs. However, this may be relevant to understanding better translocation... (Review)
Review
BACKGROUND
Quantification of asbestos fibers has been mainly performed in the lung but rarely in other organs. However, this may be relevant to understanding better translocation pathways and the oncogenic effects of asbestos on the human body. Electron microscopy is the best technology available to assess the type of fiber, dimensions, and distribution of asbestos fibers in different tissues and as a biomarker of cumulative dose.
OBJECTIVES
This scoping review aims to summarize the findings of the studies in which asbestos fibers have been quantified by electron microscopy, occasionally associated with X-ray microanalysis, in normal and pathological tissue of ten abdominal organs.
METHODS
A scoping review has been performed by searching articles that quantified asbestos fibers in abdominal organs by electron microscopy (Scanning- SEM or Transmission- TEM).
RESULTS
The 12 selected studies included 204 cases, and 325 samples were analyzed. The colon and rectum, kidney, bladder, and abdominal lymph nodes were the organs with at least ten samples available with quantification of asbestos fibers. Asbestos fibers were detected in all the abdominal organs considered: the highest value (152,32 million fibers per gram of dry tissue) was found in the colon and was identified using STEM with EDS.
CONCLUSION
The studies included were heterogeneous in terms of exposure and cases, type of samples, as well as analytical techniques, therefore we cannot confirm a specific pattern of distribution in any organ, based on the low homogeneity of the exposure status. The colon is the organ in which the number of fibers is the highest, probably because of exposure arising from both internal distribution of inhaled fibers and ingestion. Additional studies of the number of asbestos fibers in abdominal organs should be made to achieve better representativity.
Topics: Humans; Asbestos; Lung
PubMed: 38060208
DOI: 10.23749/mdl.v114i6.14946 -
Chimia 2010Asbestos - while most think they know what this material is, few understand the current issues surrounding it. Few would also realize that asbestos is the form of a... (Review)
Review
Asbestos - while most think they know what this material is, few understand the current issues surrounding it. Few would also realize that asbestos is the form of a mineral, and even fewer would know that there are different types of asbestos, that not only had different industrial applications, but pose differing health risks when inhaled. Asbestos was in wide-spread use mid-last century in many consumer products, and no doubt saved thousands of lives, but by the latter part of last century concerns over its health risk caused its use to wane, to the point it was removed from many buildings. So in many ways the asbestos story was coming to an end in the 1990s, but two events in the USA - the vermiculite ore produced from Libby, Montana which contained amphibole asbestos and was used in a million homes in the USA as attic insulation and the concern for exposure to asbestos occurring in its natural setting in El Dorado Hills, California led to an increased concern of the potential for low-level environmental exposure to asbestos to the general public. The current dilemma we find ourselves in, especially in the USA, deals with the relationships between our knowledge of handling asbestos and an understanding of its risk potential in the built environment versus the natural environment. And one perfect metaphor for this is the term used by many non-geologists to differentiate asbestos in the built vs natural environment - 'naturally occurring asbestos'. Clearly a misstatement, but only one of many we must deal with as we struggle to understand the risk to humans of natural occurrences of asbestos. This paper will try and address some of these issues centering around those occurring in the USA.
Topics: Asbestos; California; Humans; Microscopy, Electron; Mineral Fibers; Montana
PubMed: 21138165
DOI: 10.2533/chimia.2010.747 -
International Journal of Environmental... Jan 2022Due to the long lag-time for health outcomes, historical asbestos exposure measurements are valuable to support assessments of associated occupational health effects,...
OBJECTIVES
Due to the long lag-time for health outcomes, historical asbestos exposure measurements are valuable to support assessments of associated occupational health effects, and also to assess time trends and effects of preventive measures.
METHODS
Different sources of stored data were collated, assessed and refined to create a harmonized database on historical asbestos fibre concentrations measured in specific work tasks and different industries. The final database contains 9236 asbestos measurements from Danish workplaces collected from 1971 to 1997.
RESULTS
The geometric mean of asbestos concentrations in different occupations and tasks ranged from 0.003 to 35 fibres cm. Highest concentrations were registered during handling of asbestos products in the construction services during the period 1981-1997. Although all the measured asbestos exposures without the use of respiratory equipment by the worker in the period of 1971-1997 exceeded the current 8-h time-weighted average exposure limit of 0.1 fibres cm, the majority of samples collected in the earlier period of 1971 to 1980 did not exceed the exposure limit of 2 fibres cm, which was in place at the time. All exposure data obtained from 1980 and onwards were found to be one seventh of the mean fibre concentrations in the previous measurement period. The impact of time shows a clear exponentially decreasing trend-line.
CONCLUSIONS
Despite limitations in coverage of different occupations and tasks associated with the inventoried historical asbestos measurements, the data are helpful to identify specific work scenarios within an industry, where relatively high asbestos exposure levels may still occur or have occurred from 1971 to 1997.
Topics: Air Pollutants, Occupational; Asbestos; Denmark; Occupational Exposure; Occupational Health; Occupations
PubMed: 35055465
DOI: 10.3390/ijerph19020643 -
Translational Research : the Journal of... Apr 2009Asbestos causes asbestosis (pulmonary fibrosis caused by asbestos inhalation) and malignancies (bronchogenic carcinoma and mesothelioma) by mechanisms that are not fully... (Review)
Review
Asbestos causes asbestosis (pulmonary fibrosis caused by asbestos inhalation) and malignancies (bronchogenic carcinoma and mesothelioma) by mechanisms that are not fully elucidated. Despite a dramatic reduction in asbestos use worldwide, asbestos-induced lung diseases remain a substantial health concern primarily because of the vast amounts of fibers that have been mined, processed, and used during the 20th century combined with the long latency period of up to 40 years between exposure and disease presentation. This review summarizes the important new epidemiologic and pathogenic information that has emerged over the past several years. Whereas the development of asbestosis is directly associated with the magnitude and duration of asbestos exposure, the development of a malignant clone of cells can occur in the setting of low-level asbestos exposure. Emphasis is placed on the recent epidemiologic investigations that explore the malignancy risk that occurs from nonoccupational, environmental asbestos exposure. Accumulating studies are shedding light on novel mechanistic pathways by which asbestos damages the lung. Attention is focused on the importance of alveolar epithelial cell (AEC) injury and repair, the role of iron-derived reactive oxygen species (ROS), and apoptosis by the p53- and mitochondria-regulated death pathways. Furthermore, recent evidence underscores crucial roles for specific cellular signaling pathways that regulate the production of cytokines and growth factors. An evolving role for epithelial-mesenchymal transition (EMT) is also reviewed. The translational significance of these studies is evident in providing the molecular basis for developing novel therapeutic strategies for asbestos-related lung diseases and, importantly, other pulmonary diseases, such as interstitial pulmonary fibrosis and lung cancer.
Topics: Asbestos; Humans; Lung Diseases
PubMed: 19304273
DOI: 10.1016/j.trsl.2009.01.004 -
Annals of Global Health 2016The Collegium Ramazzini (CR) reaffirms its long-standing position that responsible public health action is to ban all extraction and use of asbestos, including...
The Collegium Ramazzini (CR) reaffirms its long-standing position that responsible public health action is to ban all extraction and use of asbestos, including chrysotile. This current statement updates earlier statements by the CR with a focus on global health dimensions of asbestos and asbestos-related diseases (ARDs). The ARD epidemic will likely not peak for at least a decade in most industrialized countries and for several decades in industrializing countries. Asbestos and ARDs will continue to present challenges in the arena of occupational medicine and public health, as well as in clinical research and practice, and have thus emerged as a global health issue. Industrialized countries that have already gone through the transition to an asbestos ban have learned lessons and acquired know-how and capacity that could be of great value if deployed in industrializing countries embarking on the transition. The accumulated wealth of experience and technologies in industrialized countries should thus be shared internationally through global campaigns to eliminate ARDs.
Topics: Asbestos; Asbestos, Serpentine; Asbestosis; Developed Countries; Developing Countries; Global Health; Humans; International Cooperation; Occupational Exposure
PubMed: 27325079
DOI: 10.1016/j.aogh.2016.01.019 -
Industrial Health Nov 2021Despite Italy banning use and production of asbestos in 1992, it continues to represent a risk to human health due to its permanence in the places where it was located....
Despite Italy banning use and production of asbestos in 1992, it continues to represent a risk to human health due to its permanence in the places where it was located. The aim of this work is to estimate how many schools in Rome (Italy) have asbestos containing materials (ACM), and to assess whether the location, condition and nature of ACM can influence the level of risk for student health. 3,672 schools were contacted and 1,451 participated to asbestos survey. 692 bulk samples were collected and analyzed by optical and electron microscope and Fourier transform infrared spectrometer. About 16% of the surveyed schools had ACM. Most of the ACM were not accessible to students (water tanks, boiler thermal insulations). Asbestos-cement materials and vinyl floor tiles were the most common non-friable materials found in schools and equipment insulation linings and Bunsen burner gauze mats were the friable ACM found in science laboratories. Measures to prevent or reduce asbestos hazards were applied where necessary. This study allowed to develop the awareness of the asbestos health hazard among headteachers and the need to manage these hazards appropriately. It represents the beginning of a larger study leading to ACM national mapping in schools.
Topics: Air Pollutants, Occupational; Asbestos; Humans; Italy; Rome; Schools
PubMed: 34588384
DOI: 10.2486/indhealth.2021-0036