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Wylie AG, Korchevskiy AA, Darnton L, Chatfield EJ, Peto J, Van Orden DR, Losert W, Garabrant DH. Elongate mineral particles (EMP) characteristics and mesothelioma: Summary and resolution for session I of the Monticello II conference. Environ Res 2023; 230:114754. [PMID: 36965805 DOI: 10.1016/j.envres.2022.114754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 11/04/2022] [Indexed: 05/30/2023]
Abstract
The summary contains a consensus opinion regarding the current state of the science about the dimensions of Elongate Mineral Particles (EMPs) as a factor impacting their carcinogenicity.
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Affiliation(s)
- Ann G Wylie
- Department of Geology, University of Maryland, College Park, MD, 20742, USA.
| | - Andrey A Korchevskiy
- Chemistry & Industrial Hygiene Inc., 5420 Ward Road, Suite 100, Arvada, Colorado, 80002, USA.
| | - Lucy Darnton
- UK Health and Safety Executive, 2.1 Redgrave Court, Merton Road, Bootle, Merseyside, L20 7HS, UK
| | - Eric J Chatfield
- Chatfield Technical Consulting Ltd, 2071 Dickson Road, Mississauga, Ontario, L5B 1Y8, Canada
| | - Julian Peto
- London School of Hygiene and Tropical Medicine. Keppel St., London, WC1E 7HT, UK
| | - Drew R Van Orden
- Senior Consulting Scientist, RJ Lee Group, Inc. 350 Hochberg Road, Monroeville, Pennsylvania 15146, USA
| | - Wolfgang Losert
- 1147 Physical Sciences Complex, University of Maryland, College Park, MD, 20732, USA
| | - David H Garabrant
- Emeritus Professor of Occupational Medicine and Epidemiology, University of Michigan, Ann Arbor, MI, 48104, USA
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Gu S, Bull A, Perry JK, Huang A, Hourwitz MJ, Abostate M, Fourkas JT, Korchevskiy AA, Wylie AG, Losert W. Excitable systems: A new perspective on the cellular impact of elongate mineral particles. Environ Res 2023; 230:115353. [PMID: 36702187 DOI: 10.1016/j.envres.2023.115353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 01/22/2023] [Indexed: 05/30/2023]
Abstract
We investigate how the geometry of elongate mineral particles (EMPs) in contact with cells influences esotaxis, a recently discovered mechanism of texture sensing. Esotaxis is based on cytoskeletal waves and oscillations that are nucleated, shaped, and steered by the texture of the surroundings. We find that all EMPs studied trigger an esotactic response in macrophages, and that this response dominates cytoskeletal activity in these immune cells. In contrast, epithelial cells show little to no esotactic response to the EMPs. These results are consistent with the distinct interactions of both cell types with ridged nanotopographies of dimensions comparable to those of asbestiform EMPs. Our findings raise the question of whether narrow, asbestiform EMPs may also dominate cytoskeletal activity in other types of immune cells that exhibit similar esotactic effects. These findings, together with prior studies of esotaxis, lead us to the hypothesis that asbestiform EMPs suppress the migration of immune cells and activate immune signaling, thereby outcompeting signals that would normally stimulate the immune system in nearby tissue.
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Affiliation(s)
- Shuyao Gu
- Department of Physics, University of Maryland, College Park, MD 20740, United States
| | - Abby Bull
- Department of Physics, University of Maryland, College Park, MD 20740, United States; Institute for Physical Science and Technology, University of Maryland, College Park, MD 20740, United States
| | - Jeneh K Perry
- CCDC Army Research Laboratory, Weapons and Material Research Directorate, 6300 Rodman Road, Aberdeen, Proving Ground, MD 21005, United States
| | - Amilee Huang
- Department of Biology, University of Maryland, College Park, MD 20740, United States
| | - Matt J Hourwitz
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20740, United States
| | - Mona Abostate
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20740, United States
| | - John T Fourkas
- Institute for Physical Science and Technology, University of Maryland, College Park, MD 20740, United States; Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20740, United States
| | - Andrey A Korchevskiy
- Chemistry & Industrial Hygiene, Inc., 5420 Ward Road, Suite 100, Arvada, CO 80002, United States
| | - Ann G Wylie
- Laboratory for Mineral Deposits Research, Department of Geology, University of Maryland, 8000 Regents Dr., College Park, MD 20742, United States
| | - Wolfgang Losert
- Department of Physics, University of Maryland, College Park, MD 20740, United States; Institute for Physical Science and Technology, University of Maryland, College Park, MD 20740, United States.
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Wylie AG, Korchevskiy AA. Dimensions of elongate mineral particles and cancer: A review. Environ Res 2023; 230:114688. [PMID: 36965798 DOI: 10.1016/j.envres.2022.114688] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/14/2022] [Accepted: 10/25/2022] [Indexed: 05/30/2023]
Abstract
CONTEXT Based on a decade-long exploration, dimensions of elongate mineral particles are implicated as a pivotal component of their carcinogenic potency. This paper summarizes current understanding of the discovered relationships and their importance to the protection of public health. OBJECTIVES To demonstrate the relationships between cancer risk and dimensions (length, width, and other derivative characteristics) of mineral fibers by comparing the results and conclusions of previously published studies with newly published information. METHODS A database including 59 datasets comprising 341,949 records were utilized to characterize dimensions of elongate particles. The descriptive statistics, correlation and regression analysis, combined with Monte Carlo simulation, were used to select dimensional characteristics most relevant for mesothelioma and lung cancer risk prediction. RESULTS The highest correlation between mesothelioma potency factor and weight fraction of size categories is achieved for fibers with lengths >5.6 μm and widths ≤0.26 μm (R = 0.94, P < 0.02); no statistically significant potency was found for lengths <5 μm. These results are consistent with early published estimations, though are derived from a different approach. For combinations of amphiboles and chrysotile (with a consideration of a correction factor between mineral classes), the potency factors correlated most highly with a fraction of fibers longer than 5 μm and thinner than 0.2 μm for mesothelioma, and longer than 5 μm and thinner than 0.3 μm for lung cancer. Because the proportion of long, thin particles in asbestiform vs. non-asbestiform dusts is higher, the cancer potencies of the former are predicted at a significantly higher level. The analysis of particle dimensionality in human lung burden demonstrates positive selection for thinner fibers (especially for amosite and crocidolite) and prevailing fraction of asbestiform habit. CONCLUSION Dimensions of mineral fibers can be confirmed as one of the main drivers of their carcinogenicity. The width of fibers emerges as a primary potency predictor, and fibers of all widths with lengths shorter than 5 μm seem to be non-impactful for cancer risk. The mineral dust with a fibrous component is primarily carcinogenic if it contains amphibole fibers longer than 5 μm and thinner than 0.25 μm.
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Affiliation(s)
- Ann G Wylie
- Department of Geology, University of Maryland, College Park, MD, 20742, USA.
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Korchevskiy AA, Wylie AG. Toxicological and epidemiological approaches to carcinogenic potency modeling for mixed mineral fiber exposure: the case of fibrous balangeroite and chrysotile. Inhal Toxicol 2023:1-16. [PMID: 37220304 DOI: 10.1080/08958378.2023.2213720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 05/08/2023] [Indexed: 05/25/2023]
Abstract
CONTEXT Excess mesothelioma risk was observed among chrysotile miners and millers in Balangero, Italy. The mineral balangeroite has been identified in an asbestiform habit from the Balangero chrysotile mine (Italy). Previous studies did not contain a detailed description of the fiber dimensions, thus limiting possible approaches to estimating their carcinogenic potential. OBJECTIVES To reconstruct excess mesothelioma risk based on characteristics of mixed fiber exposure. METHODS The lengths and widths of particles from a sample of balangeroite were measured by transmission electron microscopy (TEM). Statistical analysis and modeling were applied to assess the toxicological potential of balangeroite. RESULTS Balangeroite fibers are characterized as asbestiform, with geometric mean length of 10 μm, width of 0.54 μm, aspect ratio of 19, and specific surface area of 13.8 (1/μm). Proximity analysis shows dimensional characteristics of balangeroite close to asbestiform anthophyllite. Modeling estimates the average potency of balangeroite as 0.04% (95% CI 0.0058, 0.16) based on dimensional characteristics and 0.05% (95% CI-0.04, 0.24) based on epidemiological data. The available estimate of the fraction of balangeroite in the Balangero mine is very approximate. There were no data for airborne balangeroite fibers from the Balangero mine and no lung burden data are available. All estimates were performed using weight fractions of balangeroite and chrysotile. However, based on reasonable assumptions, of the seven cases of mesothelioma in the cohort, about three cases (43%) can be attributed to fibrous balangeroite. CONCLUSION The presence of different types of mineral fibers in aerosolized materials even in small proportions can explain observed cancer risks.
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Affiliation(s)
| | - Ann G Wylie
- Department of Geology, University of Maryland, College Park, College Park, MD, USA
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Korchevskiy AA, Wylie AG. Dimensional characteristics of the major types of amphibole mineral particles and the implications for carcinogenic risk assessment. Inhal Toxicol 2022; 34:24-38. [PMID: 35001771 DOI: 10.1080/08958378.2021.2024304] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Context: Though some significant advances have been made in recent decades to evaluate the importance of size and morphology (habit) of elongate mineral particles (EMPs), further research is needed to better understand the role of each dimensional metric in determining the levels of cancer potency.Objective: To determine dimensional parameters most relevant for predicting cancer potency of durable elongate particles, specifically amphibole and durable silicate minerals generally.Methods: A database on dimensional and other relevant characteristics of elongate amphibole mineral particles was created, containing particle-by-particle information for 128 099 particles. Integral statistical characteristics on dimensionality of various amphibole types and morphological habits of EMPs were calculated, compared, and correlated with published mesothelioma and lung cancer potency factors.Results: The highest absolute Pearson correlation (r = 0.97, r2 = 0.94, p < 0.05) was achieved between mesothelioma potency (RM) and specific surface area. The highest correlation with adjusted lung cancer potency was found with particle aspect ratio (AR) (r = 0.80, r2 = 0.64, p < 0.05). Cluster analysis demonstrates that fractions of thin fibers (width less than 0.15 and 0.25 µm) also closely relate both to lung cancer and RM. Asbestiform and non-asbestiform populations of amphiboles significantly differ by dimensionality and carcinogenic potency.Conclusions: Dimensional parameters and morphological habits of EMPs are the main drivers for the observable difference in cancer potency among amphibole populations.
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Affiliation(s)
| | - Ann G Wylie
- Department of Geology, University of Maryland, College Park, MD, USA
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Abstract
CONTEXT Carcinogenic properties of particulates depend, among other factors, on dimensional characteristics that affect their ability to reach sensitive tissue, to be removed or retained, and to interact with the cells. OBJECTIVE To model mesothelioma and lung cancer potency of amphibole particles based on their dimensional characteristics and mineral habit (asbestiform vs. nonasbestiform) utilizing epidemiological data and detailed size information. METHODS The datasets from recently created depository of dimensional information of elongate mineral particles were used to correlate mesothelioma and lung cancer potency with the fraction of particles in a specific size range and the ratio of length and width in different powers. In addition, the cancer potency factors were estimated and compared for 30 asbestiform, 15 nonasbestiform, and 10 mixed datasets. RESULTS For particles longer than 5 µm, the highest correlation with mesothelioma potency was achieved for width <0.22 µm, and with lung cancer <0.28 µm. The statistical power of the correlation was observed to lose significance at a maximum width of 0.6-0.7 µm. Mesothelioma potency correlated with length in the power of 1.9 divided by width in the power of 2.97, lung cancer potency with length in the power of 0.4 divided by width in the power of 1.17. The predicted cancer potencies of asbestiform, nonasbestiform, and mixed categories were significantly different. CONCLUSION While additional studies in this direction are warranted, this paper should serve as an additional confirmation for the role of fiber dimensions in the carcinogenicity of amphibole elongate mineral particles (EMPs).
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Affiliation(s)
| | - Ann G Wylie
- Department of Geology, Department of Geology, University of Maryland, College Park, MD, USA
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Wylie AG, Korchevskiy AA. Carcinogenicity of fibrous glaucophane: How should we fill the data gaps? Curr Res Toxicol 2021; 2:202-203. [PMID: 34345861 PMCID: PMC8320626 DOI: 10.1016/j.crtox.2021.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 05/04/2021] [Indexed: 11/16/2022] Open
Abstract
•The modeled glaucophane mesothelioma potency is 0.0085 % vs. 0.5 % for riebeckite.•Lung cancer potency of glaucophane is 0.36 % vs. 4.82 % for Australian crocidolite.•The fibrosity index of glaucophane (0.77) is typical for non-asbestiform amphiboles.
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Affiliation(s)
| | - Andrey A. Korchevskiy
- Chemistry & Industrial Hygiene, Inc., 10201 W. 43rd Avenue, Suite 201, Wheat Ridge, CO 80033, USA
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Wylie AG, Korchevskiy A, Segrave AM, Duane A. Modeling mesothelioma risk factors from amphibole fiber dimensionality: mineralogical and epidemiological perspective. J Appl Toxicol 2020; 40:515-524. [PMID: 32040984 DOI: 10.1002/jat.3923] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/08/2019] [Accepted: 10/15/2019] [Indexed: 11/10/2022]
Abstract
Amphiboles are common rock-forming minerals but when they form asbestos, they are known carcinogens. Mesothelioma mortality among miners and millers per the unit of asbestiform amphibole exposure varies significantly across cohorts when asbestos exposure measurements are based on the membrane filter method. Because the cohorts were exposed to different occurrences of asbestiform amphibole, variance in mesothelioma potency (RM ) among cohorts is likely due to differences in exposure characteristics not reflected by the membrane filter method. In this paper using both linear and nonlinear models we correlate RM from four mining and milling cohorts with two-dimensional parameters of the exposure. The parameters are based on the proportion of elongated minerals that are >5 μm in length from each occurrence that also have either (a) width ≤ 0.15 μm, or (b) width ≤ 0.25 μm. Based on the models we derived, it was possible to quantify RM for the occurrences of asbestiform amphibole associated with mesothelioma excess but for which epidemiologically based RM has not been published. It was demonstrated that modeled RM for amphibole occurrences in nonasbestiform habits are lower (fibrous glaucophane) or not significant (cleavage fragments). The results of the study can be used in a risk assessment of elongated mineral particles and have implications for public policy and regulations.
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Affiliation(s)
- Ann G Wylie
- Laboratory for Mineral Deposits Research, Department of Geology, University of Maryland, College Park, Maryland
| | | | | | - Andrew Duane
- Chemistry & Industrial Hygiene, Inc., Wheat Ridge, Colorado
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Wylie AG, Candela PA. Methodologies for determining the sources, characteristics, distribution, and abundance of asbestiform and nonasbestiform amphibole and serpentine in ambient air and water. J Toxicol Environ Health B Crit Rev 2015; 18:1-42. [PMID: 25825806 DOI: 10.1080/10937404.2014.997945] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Anthropogenic and nonanthropogenic (erosion) processes contribute to the continuing presence of asbestos and nonasbestos elongated mineral particles (EMP) of amphibole and serpentine in air and water of urban, rural, and remote environments. The anthropogenic processes include disturbance and deterioration of asbestos-containing materials, mining of amphibole- and serpentine-bearing rock, and disturbance of soils containing amphibole and serpentine. Atmospheric dispersal processes can transport EMP on a global scale. There are many methods of establishing the abundance of EMP in air and water. EMP include cleavage fragments, fibers, asbestos, and other asbestiform minerals, and the methods employed do not critically distinguish among them. The results of most of the protocols are expressed in the common unit of fibers per square centimeter; however, seven different definitions for the term "fiber" are employed and the results are not comparable. The phase-contrast optical method used for occupational monitoring cannot identify particles being measured, and none of the methods distinguish amphibole asbestos from other EMP of amphibole. Measured ambient concentrations of airborne EMP are low, and variance may be high, even for similar environments, yielding data of questionable value for risk assessment. Calculations based on the abundance of amphibole-bearing rock and estimates of asbestos in the conterminous United States suggest that amphibole may be found in 6-10% of the land area; nonanthropogenic erosional processes might produce on the order of 400,000 tons or more of amphibole per year, and approximately 50 g asbestos/km(2)/yr; and the order of magnitude of the likelihood of encountering rock bearing any type of asbestos is approximately 0.0001.
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Affiliation(s)
- Ann G Wylie
- a Laboratory for Mineral Deposits Research, Department of Geology , University of Maryland , College Park , Maryland , USA
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Taylor ES, Wylie AG, Mossman BT, Lower SK. Repetitive dissociation from crocidolite asbestos acts as persistent signal for epidermal growth factor receptor. Langmuir 2013; 29:6323-6330. [PMID: 23672436 DOI: 10.1021/la400561t] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Mesothelioma is an incurable form of cancer located most commonly in the pleural lining of the lungs and is associated almost exclusively with the inhalation of asbestos. The binding of asbestos to epidermal growth factor receptor (EGFR), a transmembrane signal protein, has been proposed as a trigger for downstream signaling of kinases and expression of genes involved in cell proliferation and inhibition of apoptosis. Here, we investigate the molecular binding of EGFR to crocidolite (blue asbestos; Na2(Fe(2+),Mg)3Fe2(3+)Si8O22(OH)2) in buffer solution. Atomic force microscopy measurements revealed an attractive force of interaction (i.e., bond) as EGFR was pulled from contact with long fibers of crocidolite. The rupture force of this bond increased with loading rate. According to the Bell model, the off-rate of bond dissociation (k(off)) for EGFR was 22 s(-1). Similar experiments with riebeckite crystals, the nonasbestiform variety of crocidolite, yielded a k(off) of 8 s(-1). These k(off) values on crocidolite and riebeckite are very rapid compared to published values for natural agonists of EGFR like transforming growth factor and epidermal growth factor. This suggests binding of EGFR to the surfaces of these minerals could elicit a response that is more potent than biological hormone or cytokine ligands. Signal transduction may cease for endogenous ligands due to endocytosis and subsequent degradation, and even riebeckite particles can be cleared from the lungs due to their short, equant habit. However, the fibrous habit of crocidolite leads to lifelong persistence in the lungs where aberrant, repetitious binding with EGFR may continually trigger the activation switch leading to chronic expression of genes involved in oncogenesis.
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Affiliation(s)
- Eric S Taylor
- Kent State University at Stark, 6000 Frank Ave NW, North Canton, Ohio 44720, USA.
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Affiliation(s)
- Ann G. Wylie
- a Laboratory for Mineral Deposits Research, Department of Geology, University of Maryland, College Park, MD 20742
| | - Kelly F. Bailey
- b Vulcan Materials Company, One Metroplex Dr., Birmingham, AL 35209
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Wylie AG, Skinner HC, Marsh J, Snyder H, Garzione C, Hodkinson D, Winters R, Mossman BT. Mineralogical features associated with cytotoxic and proliferative effects of fibrous talc and asbestos on rodent tracheal epithelial and pleural mesothelial cells. Toxicol Appl Pharmacol 1997; 147:143-50. [PMID: 9356317 DOI: 10.1006/taap.1997.8276] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Inhalation of asbestos fibers causes cell damage and increases in cell proliferation in various cell types of the lung and pleura in vivo. By using a colony-forming efficiency (CFE) assay, the cytotoxicity and proliferative potential of three mineral samples containing various proportions of fibrous talc were compared to NIEHS samples of crocidolite and chrysotile asbestos in cell types giving rise to tracheobronchial carcinomas, i.e., hamster tracheal epithelial (HTE) cells, and mesotheliomas, i.e., rat pleural mesothelial (RPM) cells. Characterization of mineralogical composition, surface area, and size distributions as well as proportions of fibers in all mineral samples allowed examination of data by various dose parameters including equal weight concentrations, numbers of fibers >5 micron in length, and equivalent surface areas. Exposure to samples of asbestos caused increased numbers of colonies of HTE cells, an indication of proliferative potential, but fibrous talc did not. RPMs did not exhibit increased CFE in response to either asbestos or talc samples. Decreased numbers of colonies, an indication of cytotoxicity, were observed in both cell types and were more striking at lower weight concentrations of asbestos in comparison to talc samples. However, all samples of fibrous minerals produced comparable dose-response effects when dose was measured as numbers of fibers greater than 5 micron or surface area. The unique proliferative response of HTE cells to asbestos could not be explained by differences in fiber dimensions or surface areas, indicating an important role of mineralogical composition rather than size of fibers.
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Affiliation(s)
- A G Wylie
- Department of Geology, University of Maryland, College Park, Maryland 20742, USA
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Wylie AG, Bailey KF, Kelse JW, Lee RJ. The importance of width in asbestos fiber carcinogenicity and its implications for public policy. Am Ind Hyg Assoc J 1993; 54:239-52. [PMID: 8498359 DOI: 10.1080/15298669391354621] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Evidence from human epidemiology, experimental animal implantation and inoculation studies, and lung burden studies show that fibers with widths greater than 1 micron are not implicated in the occurrence of lung cancer or mesothelioma. Furthermore, it is generally believed that certain fibers thinner than a few tenths of a micrometer must be abundant in a fiber population in order for them to be a causative agent for mesothelioma. These conclusions are fully consistent with the mineralogical characteristics of asbestos fibers, which, as fibrils, have widths of less than 1 micron and, as bundles, easily dissagregate into fibrils. Furthermore, the biological behavior of various habits of tremolite shows a clear dose-response relationship and provides evidence for a threshold between fiber width and tumor experience in animals. Public policy in regulating mineral fibers should incorporate this knowledge by altering the existing federal asbestos fiber definitions to reflect it.
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Affiliation(s)
- A G Wylie
- Department of Geology, University of Maryland, College Park 20742
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Wylie AG, Schweitzer P. The effects of sample preparation and measuring techniques on the shape and shape characterization of mineral particles: the case of wollastonite. Environ Res 1982; 27:52-73. [PMID: 6279388 DOI: 10.1016/0013-9351(82)90057-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Zoltai T, Wylie AG. DEFINITIONS OF ASBESTOS-RELATED MINERALOGICAL TERMINOLOGY. Ann N Y Acad Sci 1979. [DOI: 10.1111/j.1749-6632.1979.tb18774.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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