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The 1891-1920 birth cohort of Quebec chrysotile miners and millers: mortality 1976-88.

https://arctichealth.org/en/permalink/ahliterature219707
Source
Br J Ind Med. 1993 Dec;50(12):1073-81
Publication Type
Article
Date
Dec-1993
Author
J C McDonald
F D Liddell
A. Dufresne
A D McDonald
Author Affiliation
School of Occupational Health, McGill University, Montreal, Canada.
Source
Br J Ind Med. 1993 Dec;50(12):1073-81
Date
Dec-1993
Language
English
Publication Type
Article
Keywords
Aged
Aged, 80 and over
Asbestos, Serpentine
Asbestosis - mortality
Cause of Death
Cohort Studies
Humans
Lung Neoplasms - mortality
Male
Mesothelioma - mortality
Middle Aged
Mining
Occupational Exposure
Quebec - epidemiology
Smoking - mortality
Time Factors
Abstract
A cohort of some 11,000 men born 1891-1920 and employed for at least one month in the chrysotile mines and mills of Quebec, was established in 1966 and has been followed ever since. Of the 5351 men surviving into 1976, only 16 could not be traced; 2508 were still alive in 1989, and 2827 had died; by the end of 1992 a further 698 were known to have died, giving an overall mortality of almost 80%. This paper presents the results of analysis of mortality for the period 1976 to 1988 inclusive, obtained by the subject-years method, with Quebec mortality for reference. In many respects the standardised mortality ratios (SMRs) 20 years or more after first employment were similar to those for the period 1951-75--namely, all causes 1.07 (1951-75, 1.09); heart disease 1.02 (1.04); cerebrovascular disease 1.06 (1.07); external causes 1.17 (1.17). The SMR for lung cancer, however, rose from 1.25 to 1.39 and deaths from mesothelioma increased from eight (10 before review) to 25; deaths from respiratory tuberculosis fell from 57 to five. Among men whose exposure by age 55 was at least 300 million particles per cubic foot x years (mpcf.y), the SMR (all causes) was elevated in the two main mining regions, Asbestos and Thetford Mines, and for the small factory in Asbestos; so were the SMRs for lung cancer, ischaemic heart disease, cerebrovascular disease, and respiratory disease other than pneumoconiosis. Except for lung cancer, however, there was little convincing evidence of gradients over four classes of exposure, divided at 30, 100, and 300 mpcf.y. Over seven narrower categories of exposure up to 300 mpcf.y the SMR for lung cancer fluctuated around 1.27 with no indication of trend, but increased steeply above that level. Mortality form pneumoconiosis was strongly related to exposure, and the trend for mesothelioma was not dissimilar. Mortality generally was related systematically to cigarette smoking habit, recorded in life from 99% of survivors into 1976; smokers of 20 or more cigarettes a day had the highest SMRs not only for lung cancer but also for all causes, cancer of the stomach, pancreas, and larynx, and ischaemic heart disease. For lung cancer SMRs increased fivefold with smoking, but the increase with dust exposure was comparatively slight for non-smokers, lower again for ex-smokers, and negligible for smokers of at least 20 cigarettes a day; thus the asbestos-smoking interaction was less than multiplicative. Of the 33 deaths from mesothelioma in the cohort to date, 28 were in miners and millers and five were in employees of a small asbestos products factory where commercial amphiboles had also been used. Preliminary analysis also suggest that the risk of mesothelioma was higher in the mines and mills at Thetford Mines than in those at Asbestos. More detailed studies of these differences and of exposure-response relations for lung cancer are under way.
Notes
Cites: Br J Ind Med. 1980 Feb;37(1):11-247370189
Cites: Br J Cancer. 1982 Jan;45(1):124-357059455
Cites: Biometrics. 1983 Mar;39(1):173-846871346
Cites: Br J Ind Med. 1987 Jun;44(6):396-4013606968
Cites: Ann N Y Acad Sci. 1979;330:91-116294225
Cites: Br J Ind Med. 1992 Aug;49(8):566-751325180
Cites: Arch Environ Health. 1971 Jun;22(6):677-865574010
Cites: Arch Environ Health. 1972 Mar;24(3):189-975059627
Cites: Br J Ind Med. 1991 Aug;48(8):543-71878311
PubMed ID
8280638 View in PubMed
Less detail

Asbestos, asbestosis, and lung cancer: observations in Quebec chrysotile workers.

https://arctichealth.org/en/permalink/ahliterature207135
Source
Environ Health Perspect. 1997 Sep;105 Suppl 5:1113-9
Publication Type
Article
Date
Sep-1997
Author
B W Case
A. Dufresne
Author Affiliation
Department of Pathology, McGill University, Montreal, Canada. case@pathology.lan.mcgill.ca
Source
Environ Health Perspect. 1997 Sep;105 Suppl 5:1113-9
Date
Sep-1997
Language
English
Publication Type
Article
Keywords
Aged
Asbestos, Serpentine - adverse effects - analysis - pharmacokinetics
Asbestosis - epidemiology - pathology
Carcinogens - adverse effects - analysis - pharmacokinetics
Humans
Inhalation Exposure - adverse effects
Lung - chemistry - metabolism - pathology
Lung Neoplasms - chemically induced - epidemiology - pathology
Male
Occupational Exposure - adverse effects
Prospective Studies
Quebec - epidemiology
Smoking - epidemiology
Abstract
One prospective epidemiologic study of asbestos cement workers with radiological small opacities has been cited as a rationale for attributing excess lung cancer to asbestosis. This approach could have considerable practical value for disease attribution in an era of decreasing exposure. However, a recent International Agency for Research on Cancer review concludes that the mechanism of production of asbestos-related lung cancer are unknown. Asbestosis, therefore, cannot be a biologically effective dose marker of lung cancer susceptibility. Asbestosis nonetheless would be useful in identifying asbestos-attributable lung cancer cases if it could be proven an infallible exposure indicator. In this study, we tested this hypothesis in the chrysotile miners and millers of Quebec, Canada. We examined exposure histories, autopsy records, and lung fiber content for 111 Quebec chrysotile miners and millers. If the hypothesis of an asbestosis requirement for lung cancer attribution were accurate, we would expect as asbestosis diagnosis to separate those with lung cancer and high levels of exposure from those with lower levels of exposure in a specific and sensitive manner. This is the first such study in which historical job-based individual estimates based on environmental measurements, lung fiber content, exposure timing, and complete pathology records including autopsies were available for review. We found significant excesses of lung tremolite and chrysotile and estimated cumulative exposure in those with lung cancer and asbestosis compared to those with lung cancer without asbestosis. However, when the latter were directly compared on a case-by-case basis, there was a marked overlap between lung cancer cases with and without asbestosis regardless of the measure of exposure. Smoking habits did not differ between lung cancer cases with and without asbestosis. In regression models, smoking pack-years discriminated between those with the without lung cancer, regardless of asbestosis status. Most seriously, the pathologic diagnosis of asbestosis itself seemed arbitrary in many cases. We conclude that although the presence of pathologically diagnosed asbestosis is a useful marker of exposure, the absence of this disease must be regarded as one of many factors in determining individual exposure status and disease causation.
Notes
Cites: Br J Ind Med. 1980 Feb;37(1):11-247370189
Cites: Br J Ind Med. 1987 Feb;44(2):96-1003814551
Cites: Arch Environ Health. 1987 Jul-Aug;42(4):185-912821933
Cites: Br J Ind Med. 1989 Mar;46(3):180-72539184
Cites: Br J Ind Med. 1989 Aug;46(8):537-402550049
Cites: Am J Ind Med. 1996 Oct;30(4):398-4068892544
Cites: Br J Ind Med. 1993 Dec;50(12):1073-818280638
Cites: Ann Occup Hyg. 1994 Aug;38(4):503-18, 410-17978972
Cites: Am J Ind Med. 1994 Dec;26(6):835-87892835
Cites: Am J Ind Med. 1994 Dec;26(6):839-427892836
Cites: Lancet. 1995 Apr 29;345(8957):1074-87715339
Cites: Br J Ind Med. 1991 Apr;48(4):229-332025587
PubMed ID
9400709 View in PubMed
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Beryllium aerosol characteristics in the magnesium and aluminum transformation industry in Quebec: a comparison of four different sampling methodologies.

https://arctichealth.org/en/permalink/ahliterature148530
Source
J Occup Environ Hyg. 2009 Nov;6(11):687-97
Publication Type
Article
Date
Nov-2009
Author
A. Dufresne
C. Dion
S. Viau
Y. Cloutier
G. Perrault
Author Affiliation
Department of Environmental and Occupational Health, Faculty of Medicine, Université de Montréal, Québec, Canada. andre.dufresne@umontreal.ca
Source
J Occup Environ Hyg. 2009 Nov;6(11):687-97
Date
Nov-2009
Language
English
Publication Type
Article
Keywords
Aerosols - analysis
Air Pollutants, Occupational - analysis
Aluminum
Beryllium - analysis
Dust - analysis
Environmental Monitoring - methods
Humans
Industrial Waste - analysis
Inhalation Exposure - analysis
Magnesium
Metallurgy
Occupational Exposure - analysis
Quebec
Abstract
To examine the influence of the sampling method on beryllium (Be) exposure assessment, a study was conducted in foundries and smelters to contrast the performance of five different dust sampling devices. Six sampling surveys were conducted in four different settings, and both personal and fixed station samples were collected using the following sampling heads: IOM samplers (inhalable dust), 35-mm plastic cassettes (total dust), aluminum SKC cyclones (respirable dust), 8-stage Sierra cascade impactors, and 12-stage MOUDI impactors. In total, beryllium concentrations were determined for 66/68 inhalable dust samples, 62/62 total dust samples, 56/57 respirable dust samples, 54/64 8-stage Sierra samples, and 19/25 12-stage MOUDI samples. In the magnesium foundry and aluminum smelters, the concentrations obtained during specific tasks could exceed the actual permissible exposure limit of the province of Quebec (0.15 microg/m(3)) or of the ACGIH threshold limit value (TLV) (0.05 microg/m(3)). The median of median dust concentration ratios computed from the sampling heads at the fixed station decreased as follows: IOM (1.00) > Sierra (0.76) > 37-mm cassette (0.61) > MOUDI (0.48) > respirable (0.12). The same trends were observed with the ratios of the median of median Be concentrations at the fixed station but with a larger scattering within sampling heads as follows: IOM (1.00) > Sierra (0.69) > 37-mm cassette (0.64) > MOUDI (0.54) > respirable (0.19). The median of median ratios of dust (IOM (1.00) > Sierra (0.56) > 37-mm cassette (0.35) > respirable (0.06)) and Be (IOM (1.00) > Sierra (0.66) > 37-mm cassette (0.48) > respirable (0.11)) in dust were lower, and there was less scattering for the 37-mm cassette and SKC cyclone used during breathing zone sampling than for the same sampling heads at the fixed station. Inhalable aerosol measurements should remain the tool for estimating the risk of exposure to beryllium in these settings until a clear dose response is established for these sampling heads.
PubMed ID
19757293 View in PubMed
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Enzyme activities of lung lavage in silicosis.

https://arctichealth.org/en/permalink/ahliterature103840
Source
Lung. 1990;168(3):151-8
Publication Type
Article
Date
1990
Author
P. Larivée
A. Cantin
A. Dufresne
R. Bégin
Author Affiliation
Unité de Recherche Pulmonaire, Université de Sherbrooke, Québec, Canada.
Source
Lung. 1990;168(3):151-8
Date
1990
Language
English
Publication Type
Article
Keywords
Adult
Aged
Animals
Bronchoalveolar Lavage Fluid - enzymology
Disease Models, Animal
Dose-Response Relationship, Drug
Humans
L-Lactate Dehydrogenase - analysis - metabolism
Macrophages - enzymology
Middle Aged
Quebec
Sheep
Silicosis - enzymology - etiology
Abstract
The cytotoxic effect of quartz on lung cells has been well documented by in vitro and animal studies, but the pertinence of these findings to humans has not yet been documented. We measured lactate dehydrogenase (LDH) activities in the lung lavage of 24 long-term workers in the Québec granite industry and 25 control subjects. We found significant increases in LDH activities in the workers' lung lavage, even in the absence of established silicosis (9 subjects). We looked at a similar observation in the sheep model of early silicosis, measured quartz content of lung lavage, and found significant correlation with LDH levels (R = 0.64, p less than 0.001). All of the quartz particles in human and sheep lung lavage were in the alveolar macrophages. To test further the relationship of macrophage damage (cytotoxicity of quartz) we measured the release of LDH by sheep alveolar macrophage in 24 h cell culture under control conditions, exposure to inert dust, titanium, minusil-5 quartz, or aluminum-treated quartz. The LDH release was at control levels during titanium exposure and showed a significantly dose-related increase during quartz exposure. The latter cytotoxic effect was largely attenuated by aluminum treatment of quartz. These in vitro data agreed with previous reports. This study presents evidence of a cytotoxic effect of quartz inhalation in humans. The effect is related to the intensity of quartz retention in the lung macrophages; it is not a nonspecific dust exposure effect and can be attenuated by surface modification of the quartz.
PubMed ID
2114508 View in PubMed
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Fibers in lung tissues of mesothelioma cases among miners and millers of the township of Asbestos, Quebec.

https://arctichealth.org/en/permalink/ahliterature215410
Source
Am J Ind Med. 1995 Apr;27(4):581-92
Publication Type
Article
Date
Apr-1995
Author
A. Dufresne
M. Harrigan
S. Massé
R. Bégin
Author Affiliation
Department of Occupational Health, Faculty of Medicine, McGill University, Montréal, Quebec, Canada.
Source
Am J Ind Med. 1995 Apr;27(4):581-92
Date
Apr-1995
Language
English
Publication Type
Article
Keywords
Aged
Asbestos - adverse effects - analysis
Asbestos, Amosite - analysis
Asbestos, Amphibole - analysis
Asbestos, Crocidolite - analysis
Asbestos, Serpentine - analysis
Culture Techniques
Humans
Lung Neoplasms - chemistry - etiology - pathology
Male
Mesothelioma - chemistry - etiology - pathology
Middle Aged
Mining
Occupational Diseases - etiology - pathology
Quebec
Textile Industry
Abstract
Twenty cases of mesothelioma among miners of the township of Asbestos, Quebec, Canada, have been reported. To further explore the mineral characteristics of various fibrous material, we studied the fibrous inorganic content of postmortem lung tissues of 12 of 20 available cases. In each case, we measured concentrations of chrysotile, amosite, crocidolite, tremolite, talc-anthophyllite, and other fibrous minerals. The average diameter, length, and length-to-diameter ratio of each type of fiber were also calculated. For total fibers > 5 microns, we found > 1,000 asbestos fibers per mg tissue (f/mg) in all cases; tremolite was above 1,000 f/mg in 8 cases, chrysotile in 6 cases, crocidolite in 4 cases, and talc anthophyllite in 5 cases. Among cases with asbestos fibers, the tremolite count was highest in 7 cases, chrysotile in 3 cases, and crocidolite in 2 cases. The geometric mean concentrations of fibers > or = 5 microns were in the following decreasing order: tremolite > crocidolite > chrysotile > other fibers > talc-anthophyllite > amosite. For total fibers 1,000 fibers per mg tissue (f/mg) in all cases; tremolite was above 1,000 f/mg in 12 cases, chrysotile in 8 cases, crocidolite in 7 cases, and talc-anthophyllite in 6 cases. Tremolite was highest in 8 cases, chrysotile in 2 cases, and crocidolite and amosite in 2 cases. The geometric mean concentrations of fibers other fibers > chrysotile > crocidolite > talc-anthophyllite > amosite. We conclude, on the basis of the lung burden analyses of 12 mesothelioma cases from the Asbestos township of Quebec, that the imported amphibole (crocidolite and amosite) were the dominant fibers retained in the lung tissue in 2/12 cases. In 10/12 cases, fibers from the mine site (chrysotile and tremolite) were found at highest counts; tremolite was clearly the highest in 6, chrysotile in 2, and 2 cases had about the same counts for tremolite and chrysotile. If a relation of fiber burden-causality of mesothelioma is accepted, mesothelioma would be likely caused by amphibole contamination of the plant in 2/12 cases and by the mineral fibers (tremolite and chrysotile) from the mine site in the 10 other cases.
PubMed ID
7793429 View in PubMed
Less detail

Lung mineral fibers of former miners and millers from Thetford-Mines and asbestos regions: a comparative study of fiber concentration and dimension.

https://arctichealth.org/en/permalink/ahliterature195329
Source
Arch Environ Health. 2001 Jan-Feb;56(1):65-76
Publication Type
Article
Author
A. Nayebzadeh
A. Dufresne
B. Case
H. Vali
A E Williams-Jones
R. Martin
C. Normand
J. Clark
Author Affiliation
Department of Epidemiology, Biostatistics and Occupational Health, McGill University Montreal, Québec, Canada.
Source
Arch Environ Health. 2001 Jan-Feb;56(1):65-76
Language
English
Publication Type
Article
Keywords
Aged
Aged, 80 and over
Asbestos, Amosite - adverse effects - analysis - classification
Asbestos, Amphibole - adverse effects - analysis - classification
Asbestos, Crocidolite - adverse effects - analysis - classification
Asbestosis - epidemiology - etiology - pathology
Autopsy
Environmental Monitoring - methods
Epidemiological Monitoring
Extraction and Processing Industry
Humans
Incidence
Microscopy, Electron
Middle Aged
Mineral Fibers - adverse effects - analysis - classification
Mining
Occupational Exposure - adverse effects - analysis
Quebec - epidemiology
Spectrometry, X-Ray Emission
Abstract
Fiber dimension and concentration may vary substantially between two necropsy populations of former chrysotile miners and millers of Thetford-Mines and Asbestos regions. This possibility could explain, at least in part, the higher incidence of respiratory diseases among workers from Thetford-Mines than among workers from the Asbestos region. The authors used a transmission electron microscope, equipped with an x-ray energy-dispersive spectrometer, to analyze lung mineral fibers of 86 subjects from the two mining regions and to classify fiber sizes into three categories. The most consistent difference was the higher concentration of tremolite in lung tissues of workers from Thetford-Mines, compared with workers from the Asbestos region. Amosite and crocidolite were also detected in lung tissues of several workers from the Asbestos region. No consistent and biologically important difference was found for fiber dimension; therefore, fiber dimension does not seem to be a factor that accounts for the difference in incidence of respiratory diseases between the two groups. The greater incidence of respiratory diseases among workers of Thetford-Mines can be explained by the fact that they had greater exposure to fibers than did workers at the Asbestos region. Among the mineral fibers studied, retention of tremolite fibers was most apparent.
PubMed ID
11256859 View in PubMed
Less detail

Mesothelioma in Quebec chrysotile miners and millers: epidemiology and aetiology.

https://arctichealth.org/en/permalink/ahliterature207076
Source
Ann Occup Hyg. 1997 Dec;41(6):707-19
Publication Type
Article
Date
Dec-1997
Author
A D McDonald
B W Case
A. Churg
A. Dufresne
G W Gibbs
P. Sébastien
J C McDonald
Author Affiliation
Department of Epidemiology, McGill University, Montreal, Canada.
Source
Ann Occup Hyg. 1997 Dec;41(6):707-19
Date
Dec-1997
Language
English
Publication Type
Article
Keywords
Aged
Aged, 80 and over
Asbestos - adverse effects
Asbestos, Amphibole - adverse effects
Humans
Logistic Models
Lung - pathology
Male
Mesothelioma - chemically induced - mortality
Occupational Diseases - chemically induced - mortality
Odds Ratio
Quebec - epidemiology
Abstract
In a cohort of some 11,000 men born 1891-1920 and employed in the Quebec chrysotile production industry, including a small asbestos products factory, of 9780 men who survived into 1936, 8009 are known to have died before 1993, 38 probably from mesothelioma--33 in miners and millers and five in factory workers. Among the 5041 miners and millers at Thetford Mines, there had been 4125 deaths from all causes, including 25 (0.61%) from mesothelioma, a rate of 33.7 per 100,000 subject-years; the corresponding figures for the 4031 men at Asbestos were eight out of 3331 (0.24%, or 13.2 per 100,000 subject-years). At the factory in Asbestos, where all 708 employees were potentially exposed to crocidolite and/or amosite, there were 553 deaths, of which five (0.90%) were due to mesothelioma; the rate of 46.2 per 100,000 subject-years was 3.5 times higher than among the local miners and millers. Six of the 33 cases in miners and millers were in men employed from 2 to 5 years and who might have been exposed to asbestos elsewhere; otherwise, the 22 cases at Thetford were in men employed 20 years or more and the five at Asbestos for at least 30 years. The cases at Thetford were more common in miners than in millers, whereas those at. Asbestos were all in millers. Within Thetford Mines, case-referent analyses showed a substantially increased risk associated with years of employment in a circumscribed group of five mines (Area A), but not in a peripherally distributed group of ten mines (Area B); nor was the risk related to years employed at Asbestos, either at the mine and mill or at the factory. There was no indication that risks were affected by the level of dust exposure. A similar pattern in the prevalence of pleural calcification had been observed at Thetford Mines in the 1970s. These geographical differences, both within the Thetford region and between it and Asbestos, suggest that the explanation is mineralogical. Lung tissue analyses showed that the concentration of tremolite fibres was much higher in Area A than in Area B, a finding compatible with geological knowledge of the region. These findings, probably related to the far greater biopersistence of amphibole fibres than chrysotile, have important implications in the control of asbestos related disease and for wider aspects of fibre toxicology.
Notes
Comment In: Ann Occup Hyg. 2001 Jun;45(4):327-9; author reply 336-811414249
PubMed ID
9375529 View in PubMed
Less detail

Mineral fiber content of lungs in patients with mesothelioma seeking compensation in Qu├ębec.

https://arctichealth.org/en/permalink/ahliterature212825
Source
Am J Respir Crit Care Med. 1996 Feb;153(2):711-8
Publication Type
Article
Date
Feb-1996
Author
A. Dufresne
R. Bégin
A. Churg
S. Massé
Author Affiliation
Department of Occupational Health, Faculty of Medicine, McGill University, Montréal, Québec, Canada.
Source
Am J Respir Crit Care Med. 1996 Feb;153(2):711-8
Date
Feb-1996
Language
English
Publication Type
Article
Keywords
Aged
Asbestos
Electron Probe Microanalysis
Humans
Iron
Lung - pathology
Mesothelioma - pathology
Microscopy, Electron
Middle Aged
Mineral Fibers
Occupational Diseases - pathology
Peritoneal Neoplasms - pathology
Pleural Neoplasms - pathology
Quebec
Workers' Compensation
Abstract
Asbestos fibers (AF) and ferruginous bodies (FB) in lung parenchyma from 50 workers seeking compensation from the Workers' Compensation Board of Québec for pleural or peritoneal mesothelioma were analyzed using transmission electron microscopy (TEM) equipped with energy-dispersive spectrometer (EDS) and phase-contrast microscopy (PCM). These workers had been occupationally exposed in mining and milling activities (12 were from Asbestos Township and 11 from Thetford Mines) and 27 were from other types of industry (asbestos factory, shipyard, etc.). For comparison, analyses of lung tissue at autopsy were done in a group of 49 subjects from a reference population. A 95% confidence interval upper limit of 540 AF or = 5 microns/mg dried lung tissue were found for the reference population. Similarly, a concentration of FB of 142 FB/g constituted the upper limit of detectable FB in the lungs of the reference population. Forty-eight of the 50 workers with mesothelioma had either a ferruginous body or total asbestos fiber count greater than the 95% confidence interval for the reference population; the remaining two had amosite and/or crocidolite concentrations greater than the 95% confidence interval for the reference population. The fiber types were different in the three groups, with the lungs of workers from Thetford Mines containing only chrysotile and tremolite, those from Asbestos Township containing chrysotile, tremolite, amosite, and crocidolite, and those in other industries containing largely amosite and crocidolite. We conclude that in this population of workers seeking compensation for mesothelioma, fiber analysis confirmed occupational asbestos exposure in every case. The fiber types responsible for the tumors are probably different in the three different groups.
PubMed ID
8564122 View in PubMed
Less detail

Relation between lung asbestos fibre burden and exposure indices based on job history.

https://arctichealth.org/en/permalink/ahliterature217790
Source
Occup Environ Med. 1994 Jul;51(7):461-9
Publication Type
Article
Date
Jul-1994
Author
K. Takahashi
B W Case
A. Dufresne
R. Fraser
T. Higashi
J. Siemiatycki
Author Affiliation
Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
Source
Occup Environ Med. 1994 Jul;51(7):461-9
Date
Jul-1994
Language
English
Publication Type
Article
Keywords
Adult
Aged
Asbestos - analysis - chemistry
Asbestos, Amosite - analysis - chemistry
Asbestos, Crocidolite - analysis - chemistry
Canada - epidemiology
Case-Control Studies
Humans
Lung - chemistry
Male
Middle Aged
Multivariate Analysis
Occupational Exposure
Regression Analysis
Smoking
Time Factors
Abstract
Lung asbestos burden was compared with exposure indices derived from job history interviews in 42 male subjects originating from the Montréal Case-Control Study project, 12 of whom had documented asbestos exposed job histories. Job interview data consisting of a chronological timetable of job histories were translated into detailed exposure indices by an expert group of hygienists and chemists. Total and individual asbestos fibre type concentrations were quantified by transmission electron microscopy with fibre identification by energy dispersive chi ray spectrometry after deparaffinisation of tissue blocks and low temperature plasma ashing. Geometric mean or median asbestos content was higher in subjects with an asbestos exposed job history than those without for retained dose of amosite, total commercial amphiboles, and total asbestos fibre. Except for crocidolite fibre diameter, which was significantly less in the lungs of exposed workers, no consistent differences were found in measurements of fibre dimension for any fibre type. Subgroups of subjects exposed to silica, metals, or smokers and non-smokers without significant occupational exposure showed varying patterns of lung asbestos fibre type deficit compared with the asbestos exposed subgroup. There was an overall trend for higher lung asbestos content proportional to higher exposure indices for asbestos representing concentration, frequency, and reliability. These exposure indices as well as duration of exposure (in years) were independent predictors of total asbestos content in regression analyses when combined in a model with age. Stepwise regression indicated that exposure concentration was the most important variable, explaining 32% of the total variation in total asbestos content. Smoking, whether expressed in ever or never smoked dichotomy or in smoked-years, had no relation to lung asbestos content in this model.
Notes
Cites: J Occup Med. 1985 Jun;27(6):420-64020500
Cites: Environ Res. 1983 Aug;31(2):374-806884297
Cites: Br J Ind Med. 1986 Jan;43(1):18-283947558
Cites: Br J Ind Med. 1986 Oct;43(10):667-763778837
Cites: Arch Environ Health. 1987 Jul-Aug;42(4):185-912821933
Cites: Scand J Work Environ Health. 1987 Dec;13(6):486-923433050
Cites: Arch Environ Health. 1988 Mar-Apr;43(2):83-93377561
Cites: Cancer. 1989 Apr 15;63(8):1544-72924262
Cites: Br J Ind Med. 1989 Mar;46(3):180-72539184
Cites: Am Rev Respir Dis. 1990 Dec;142(6 Pt 1):1453-82252267
Cites: Ann Occup Hyg. 1990 Oct;34(5):427-412281888
Cites: Br J Ind Med. 1991 Jan;48(1):48-521993160
Cites: Ann N Y Acad Sci. 1991 Dec 31;643:61-701809175
Cites: J Natl Cancer Inst. 1981 Feb;66(2):217-256935472
Cites: Am J Epidemiol. 1986 Feb;123(2):235-493946373
PubMed ID
8044245 View in PubMed
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Tentative explanatory variable of lung dust concentration in gold miners exposed to crystalline silica.

https://arctichealth.org/en/permalink/ahliterature205025
Source
J Expo Anal Environ Epidemiol. 1998 Jul-Sep;8(3):375-98
Publication Type
Article
Author
A. Dufresne
P. Loosereewanich
R. Bégin
C. Dion
D. Ecobichon
D C Muir
A C Ritchie
G. Perrault
Author Affiliation
McGill University, Department of Occupational Health, Faculty of Medicine, Montréal, Québec, Canada. cydu@musica.mcgill.ca
Source
J Expo Anal Environ Epidemiol. 1998 Jul-Sep;8(3):375-98
Language
English
Publication Type
Article
Keywords
Aged
Gold
Humans
Lung - pathology
Lung Neoplasms - pathology
Male
Mining
Occupational Exposure - analysis
Ontario
Quartz - adverse effects
Silicon Dioxide - adverse effects
Silicosis - etiology
Time Factors
Abstract
The first objective of the study was to investigate the relationships between quantitative lung mineral dust burdens, dust exposure history, and pathological fibrosis grading in silicotic workers. The second objective was to evaluate the association between particle size parameters, concentration of retained silica particles and the severity of the silicosis. Sixty-seven paraffin-embedded lung tissue samples of silicotic patients were analyzed. The cases of silicosis included 39 non-lung cancer patients and 28 patients with lung cancer. All of the cases were gold miners in the Province of Ontario, Canada.
Particles, both angular and fibrous, were extracted from lung parenchyma by a bleach digestion method, mounted on copper microscopic grids by a carbon replica technique, and analyzed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). Quartz concentration was also determined by X-ray diffraction (XRD) on a silver membrane filter after the extraction from the lung parenchyma.
Total particles, silica, clay, and quartz also increase in concentration with increased age at death, although the trends are not statistically significant. Quartz concentration has a statistically significant correlation with the silicosis severity score (r = +0.45, p
PubMed ID
9679218 View in PubMed
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