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Shao Y, MacLehose RF, Lin L, Hwang J, Alexander BH, Mandel JH, Ramachandran G. A Bayesian Approach for Determining the Relationship Between Various Elongate Mineral Particles (EMPs) Definitions. Ann Work Expo Health 2020; 64:993-1006. [PMID: 33196824 DOI: 10.1093/annweh/wxaa074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 04/12/2020] [Accepted: 06/25/2020] [Indexed: 11/13/2022] Open
Abstract
A variety of dimensions (lengths and widths) of elongate mineral particles (EMPs) have been proposed as being related to health effects. In this paper, we develop a mathematical approach for deriving numerical conversion factors (CFs) between these EMP exposure metrics and applied it to the Minnesota Taconite Health Worker study which contains 196 different job exposure groups (28 similar exposure groups times 7 taconite mines). This approach comprises four steps: for each group (i) obtain EMP dimension information using ISO-TEM 10312/13794 analysis; (ii) use bivariate lognormal distribution to characterize overall EMP size distribution; (iii) use a Bayesian approach to facilitate the formation of the bivariate lognormal distribution; (iv) derive conversion factors between any pair of EMP definitions. The final CFs allow the creation of job exposure matrices (JEMs) for alternative EMP metrics using existing EMP exposures already characterized according to the National Institute of Occupational Safety and Health (NIOSH)-defined EMP exposure metric (length >5 µm with an aspect ratio ≥3.0). The relationships between the NIOSH EMP and other EMP definitions provide the basis of classification of workers into JEMs based on alternate definitions of EMP for epidemiological studies of mesothelioma, lung cancer, and non-malignant respiratory disease.
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Affiliation(s)
- Yuan Shao
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, MN, USA
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Richard F MacLehose
- Division of Epidemiology & Community Health, University of Minnesota, Minneapolis, MN, USA
| | - Lifeng Lin
- Department of Statistics, Florida State University, Tallahassee, FL, USA
| | - Jooyeon Hwang
- Department of Occupational and Environmental Health, Hudson College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Bruce H Alexander
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Jeffrey H Mandel
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Gurumurthy Ramachandran
- Department of Environmental Health and Engineering, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
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Allen EM, Alexander BH, MacLehose RF, Nelson HH, Ryan AD, Ramachandran G, Mandel JH. Occupational exposures and lung cancer risk among Minnesota taconite mining workers. Occup Environ Med 2015; 72:633-9. [PMID: 25977445 DOI: 10.1136/oemed-2015-102825] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 04/14/2015] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To examine the association between employment duration, elongate mineral particle (EMP) exposure, silica exposure and the risk of lung cancer in the taconite mining industry. METHODS We conducted a nested case-control study of lung cancer within a cohort of Minnesota taconite iron mining workers employed by any of the mining companies in operation in 1983. Lung cancer cases were identified by vital records and cancer registry data through 2010. Two age-matched controls were selected from risk sets of cohort members alive and lung cancer free at the time of case diagnosis. Calendar time-specific exposure estimates were made for every job and were used to estimate workers' cumulative exposures. ORs and 95% CIs were estimated using conditional logistic regression. We evaluated total lung cancer risk and risk of histological subtype by total work duration and by cumulative EMP, and silica exposure by quartile of the exposure distribution. RESULTS A total of 1706 cases and 3381 controls were included in the analysis. After adjusting for work in haematite mining, asbestos exposure and sex, the OR for total duration of employment was 0.99 (95% CI 0.96 to 1.01). The ORs for quartile 4 versus 1 of EMP and silica exposure were 0.82 (95% CI 0.57 to 1.19) and 0.97 (95% CI 0.70 to 1.35), respectively. The risk of each histological subtype of lung cancer did not change with increasing exposure. CONCLUSIONS This study suggests that the estimated taconite mining exposures do not increase the risk of developing lung cancer.
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Affiliation(s)
- Elizabeth M Allen
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota, USA Department of Family Medicine and Community Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - Bruce H Alexander
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Richard F MacLehose
- Division of Epidemiology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Heather H Nelson
- Division of Epidemiology, University of Minnesota, Minneapolis, Minnesota, USA
| | - Andrew D Ryan
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Gurumurthy Ramachandran
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jeffrey H Mandel
- Division of Environmental Health Sciences, University of Minnesota, Minneapolis, Minnesota, USA
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Allen EM, Alexander BH, MacLehose RF, Ramachandran G, Mandel JH. Mortality experience among Minnesota taconite mining industry workers. Occup Environ Med 2014; 71:744-9. [DOI: 10.1136/oemed-2013-102000] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Hwang J, Ramachandran G, Raynor PC, Alexander BH, Mandel JH. The relationship between various exposure metrics for elongate mineral particles (EMP) in the taconite mining and processing industry. J Occup Environ Hyg 2014; 11:613-24. [PMID: 24512074 DOI: 10.1080/15459624.2014.890287] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Different dimensions of elongate mineral particles (EMP) have been proposed as being relevant to respiratory health end-points such as mesothelioma and lung cancer. In this article, a methodology for converting personal EMP exposures measured using the National Institute for Occupational Safety and Health (NIOSH) 7400/7402 methods to exposures based on other size-based definitions has been proposed and illustrated. Area monitoring for EMP in the taconite mines in Minnesota's Mesabi Iron Range was conducted using a Micro Orifice Uniform Deposit Impactor (MOUDI) size-fractionating sampler. EMP on stages of the MOUDI were counted and sized according to each EMP definition using an indirect-transfer transmission electron microscopy (ISO Method 13794). EMP were identified using energy-dispersive x-ray and electron diffraction analysis. Conversion factors between the EMP counts based on different definitions were estimated using (1) a linear regression model across all locations and (2) a location-specific ratio of the count based on each EMP definition to the NIOSH 7400/7402 count. The highest fractions of EMP concentrations were found for EMP that were 1-3 μm in length and 0.2-0.5 μm in width. Therefore, the current standard NIOSH Method 7400, which only counts EMP >5 μm in length and ≥ 3 in aspect ratio, may underestimate amphibole EMP exposures. At the same time, there was a high degree of correlation between the exposures estimated according to the different size-based metrics. Therefore, the various dimensional definitions probably do not result in different dose-response relationships in epidemiological analyses. Given the high degree of correlation between the various metrics, a result consistent with prior research, a more reasonable metric might be the measurement of all EMP irrespective of size. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: figures detailing EMP concentration.].
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Affiliation(s)
- Jooyeon Hwang
- a Division of Environmental Health Sciences, School of Public Health, University of Minnesota , Minneapolis , Minnesota
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Wilson R, McConnell EE, Ross M, Axten CW, Nolan RP. Risk assessment due to environmental exposures to fibrous particulates associated with taconite ore. Regul Toxicol Pharmacol 2008; 52:S232-45. [DOI: 10.1016/j.yrtph.2007.11.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Accepted: 11/02/2007] [Indexed: 10/22/2022]
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Brunner WM, Williams AN, Bender AP. Investigation of exposures to commercial asbestos in northeastern Minnesota iron miners who developed mesothelioma. Regul Toxicol Pharmacol 2008; 52:S116-20. [PMID: 17988773 DOI: 10.1016/j.yrtph.2007.09.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Accepted: 09/30/2007] [Indexed: 11/15/2022]
Affiliation(s)
- Wendy M Brunner
- Chronic Disease and Environmental Epidemiology, Minnesota Department of Health, 85 East 7th Place, P.O. Box 64882, St. Paul, MN 55164-0882, USA.
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Gamble JF, Gibbs GW. An evaluation of the risks of lung cancer and mesothelioma from exposure to amphibole cleavage fragments. Regul Toxicol Pharmacol 2008; 52:S154-86. [DOI: 10.1016/j.yrtph.2007.09.020] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Accepted: 09/30/2007] [Indexed: 12/26/2022]
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Langer AM. Rapporteur’s Report Session 2: Characterization of fibrous minerals:. Regul Toxicol Pharmacol 2008; 52:S73-4. [DOI: 10.1016/j.yrtph.2008.06.003] [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] [Received: 05/23/2008] [Accepted: 06/03/2008] [Indexed: 11/22/2022]
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Langer AM. Identification and enumeration of asbestos fibers in the mining environment: mission and modification to the Federal Asbestos Standard. Regul Toxicol Pharmacol 2008; 52:S207-17. [PMID: 18342420 DOI: 10.1016/j.yrtph.2008.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2008] [Accepted: 01/15/2008] [Indexed: 11/23/2022]
Abstract
Since the promulgation of the first Federal Asbestos Standard by the Occupational Safety and Health Administration in 1972, other federal agencies have modified the standard to better carry on their own unique missions. The instruments used to identify and measure asbestos, the sampling protocol, and the criteria used to define asbestos, have been modified to some degree. The Mine Safety and Health Administration regulates and controls asbestos dust in the mining and mineral commodity industries. However, crushed stone and processed ores contain mineral fragments that are frequently difficult to distinguish from asbestos. Mineral nomenclature, instruments for particle analysis, and sampling strategy must be accommodated to some degree to make asbestos control workable and meaningful. Precedent in other agencies has made consideration of these changes possible. Newly identified amphibole asbestos minerals have further complicated the agency's regulatory charge. Changes in its Asbestos Standard are now being considered. Crushed taconite ore in the Eastern Mesabi highlights many of these issues.
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Abstract
The relationship between asbestos exposure and gastrointestinal malignancies is unlike the well-established correlation between occupational asbestos exposure and the subsequent development of pleuropulmonary neoplasms and mesotheliomas. Cohort studies on occupationally exposed workers suggest an association between asbestos and gastrointestinal cancer, but evaluation of dose-response, tissue analysis, animal experiment, and cell culture data yield inconsistent conclusions. No simplistic cause-effect relationship can be ascribed to asbestos at the present time, and the answer to the question, "Does asbestos exposure cause cancer?" must await the results of additional studies.
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Maresca GP, Puffer JH, Germine M. Asbestos in lake and reservoir waters of Staten Island, New York: Source, concentration, mineralogy, and size distribution. ACTA ACUST UNITED AC 1984; 6:201-10. [DOI: 10.1007/bf02509928] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
Fibers of the amphibole mineral series have been demonstrated in the dust from an open taconite ore mine. Though the total dust levels in some places are high, exposures to fibers are below one fiber/cc. The energy dispersive X-ray spectra of the amphibole fibers correspond to those of cummingtonite-grunerite, hornblende, or actinolite. The same type and size distribution of fibers were found during post mortem analyses of lung tissue from two previously exposed miners. The pathological examination revealed an undifferentiated small cell carcinoma of left lung as well as pulmonary fibrosis in one of the cases. In the second case a poorly differentiated squamous cell carcinoma of left lung was found along with silicosis.
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Langer AM. Host rocks and gangue minerals in relation to pneumoconiosis and cancer. Am J Ind Med 1981; 2:89-90. [PMID: 6295144 DOI: 10.1002/ajim.4700020202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Abstract
It has been widely assumed, especially in the absence of other explanations, that lung cancer and nasal sinus cancers observed among nickel smelter workers are the result of the carcinogenicity of nickel. Although there may be such influence, supplementary hypotheses are also possible. The nickeliferous ores from at least one major smelter in New Caledonia (excess numbers of cancers have been found in these smelter workers) are derived from serpentinized host rocks which contain large amounts of chrysotile asbestos. Analysis indicates that nickel ores from this area are heavily contaminated by these fibers. The deposits are mined for their nickel content, but workers may be exposed to the asbestos fibers contained in the deposits. Hygiene measures limited to the avoidance of nickel may be inadequate under such circumstances and should be reevaluated so as to prevent the inhalation of asbestos-containing dusts.
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