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29 records – page 1 of 3.

Effects of the intensity and timing of asbestos exposure on lung cancer risk at two mining areas in Quebec.

https://arctichealth.org/en/permalink/ahliterature204259
Source
J Occup Environ Med. 1998 Sep;40(9):821-8
Publication Type
Article
Date
Sep-1998
Author
P M Vacek
Author Affiliation
Department of Medical Biostatistics, University of Vermont College of Medicine, Burlington 05405, USA.
Source
J Occup Environ Med. 1998 Sep;40(9):821-8
Date
Sep-1998
Language
English
Publication Type
Article
Keywords
Adult
Asbestos - adverse effects
Case-Control Studies
Chi-Square Distribution
Cohort Studies
Female
Humans
Logistic Models
Lung Neoplasms - epidemiology - etiology
Male
Mining
Occupational Diseases - epidemiology - etiology
Occupational Exposure
Quebec - epidemiology
Risk factors
Smoking - adverse effects
Time Factors
Abstract
Mortality data from 9609 workers at two asbestos mining areas in Quebec were analyzed to assess the effects of the intensity and timing of exposure on lung cancer risk. Summary exposure measures based on differing assumption were computed for lung cancer cases and matched controls and were fitted to the data using conditional logistic regression. A non-linear relationship between intensity and risk fit both mining areas, but risk was greater at one area than the other. At the mine with lower risk, exposure occurring more than 30 years prior to death had little effect, while at the other mine risk did not vary with time since exposure and men starting employment before 1924 were at elevated risk. The results point to differences in dust composition at the two areas and illustrate the difficulties in estimating risk.
PubMed ID
9777567 View in PubMed
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Respiratory health in chrysotile asbestos miners in British Columbia: a longitudinal study.

https://arctichealth.org/en/permalink/ahliterature232893
Source
Br J Ind Med. 1988 Jul;45(7):459-63
Publication Type
Article
Date
Jul-1988
Author
D A Enarson
V. Embree
L. MacLean
S. Grzybowski
Author Affiliation
Respiratory Division, Vancouver General Hospital, University of British Columbia, Canada.
Source
Br J Ind Med. 1988 Jul;45(7):459-63
Date
Jul-1988
Language
English
Publication Type
Article
Keywords
Adult
Asbestos - adverse effects
Asbestos, Serpentine
British Columbia
Humans
Longitudinal Studies
Lung - physiopathology - radiography
Middle Aged
Mining
Occupational Diseases - etiology - physiopathology
Respiration Disorders - etiology - physiopathology
Spirometry
Vital Capacity
Abstract
A respiratory survey was undertaken in chrysotile asbestos miners in British Columbia consisting of a questionnaire, spirometry, chest radiography, and physical examination. The tests were performed in 1977 and again in 1983. The population groups studied included 63 "exposed" (working in the plant more than nine years), 52 "controls" (working in the plant less than five years), and 38 residents of the village at the minesite. A subset of 39 was identified with high exposure (worked in the mill more than five years). Measured levels of environmental particulates were similar over the entire period of operation of the plant (1.4 to 14.0 million particles per cubic foot and 0.7-88.0 fibres/cc in the mill; 0.2 to 2.7 mpcf and 0.6 to 9.3 f/cc in the mine). The exposed groups were more likely to report cough and breathlessness than the two other groups and were also more likely to have abnormal FVC and chest x ray films (the latter not significant, p greater than 0.05) and to be more likely to have a combination of these abnormalities. There was no trend to progression in the combination of abnormalities associated with exposure on follow up. The heavily exposed group showed a significantly worse trend in FVC. This adverse trend was confined to those with initial abnormalities. Tobacco smoking did not increase the trend to progression in this group.
Notes
Cites: Am Rev Respir Dis. 1971 Jan;103(1):57-675540840
Cites: Arch Environ Health. 1972 Jun;24(6):388-4005031565
Cites: Arch Environ Health. 1972 Jun;24(6):401-95031566
Cites: Arch Environ Health. 1974 Feb;28(2):61-84809914
Cites: Am Rev Respir Dis. 1976 Jul;114(1):187-227779552
Cites: Ann N Y Acad Sci. 1979;330:341-52294186
Cites: Ann N Y Acad Sci. 1979;330:35-52294187
Cites: Scand J Work Environ Health. 1982;8 Suppl 1:105-107100836
Cites: Am Rev Respir Dis. 1986 Jul;134(1):125-73014932
PubMed ID
2840111 View in PubMed
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Radiological findings as predictors of mortality in Quebec asbestos workers.

https://arctichealth.org/en/permalink/ahliterature245550
Source
Br J Ind Med. 1980 Aug;37(3):257-67
Publication Type
Article
Date
Aug-1980
Author
F D Liddell
J C McDonald
Source
Br J Ind Med. 1980 Aug;37(3):257-67
Date
Aug-1980
Language
English
Publication Type
Article
Keywords
Adult
Aged
Asbestos - adverse effects
Asbestosis - mortality - radiography
Humans
Lung - radiography
Lung Neoplasms - etiology - mortality - radiography
Male
Middle Aged
Mining
Occupational Diseases - etiology - mortality - radiography
Quebec
Risk
Abstract
Two cohorts of chrysotile miners and millers in Quebec were selected to study the extent to which chest radiographs taken while still employed predict mortality. The paper presents mainly findings in much the larger cohort, which consisted of 4559 men (two-thirds past workers) whose latest radiograph had been assessed by one of six experienced readers into what became the UICC/Cincinnati (U/C) classification; by the end of 1975 there had been 1543 deaths in this cohort. The findings were generally confirmed in the other cohort, comprising 988 current male workers, who had been examined in 1967-8 by questionnaires on respiratory symptoms and smoking and by lung function tests, and for whom all six readers had assessed their 1966 radiographs into the U/C classification; 130 men had died by the end of 1975. Men with any radiographic abnormality, heavy dust exposure, or a history of cigarette smoking had relative risks (RRs) of total mortality greater than unity. Death from pneumoconiosis was associated with small parenchymal opacities, usually irregular, of profusion l/l or more, and with heavy dust exposure but not with smoking. Most who died from lung cancer had smoked cigarettes, or had been heavily exposed to dust, or both. Small parenchymal opacities were present in most but not all the excess deaths due to lung cancer. Deaths from other malignant diseases showed no consistent dust or x-ray patterns. RRs of deaths from most other causes were raised for certain radiographic features. Failures in forecasting mortality were primarily due to deaths in which asbestos-related disease was not the primary cause but may have been a contributing factor. The main findings validated the U/C classification convincingly, particulary as the films had been taken as routine and were of modest quality. Despite objective rules for the reading and the fact that all six readers were contributing to the development of the classification, there was inevitably some observer variation. The importance of radiographic technique and the need for careful control of the reading is evident. Our results provide support for the use of the chest radiograph for surveillance of asbestos workers, and for environmental monitoring. Its protective value for individual workers, however, is limited to the extent that radiological progression continues after withdrawal from exposure, and by the carcinogenic risk associated with dust already retained.
Notes
Cites: Chest. 1970 Jul;58(1):57-675425303
Cites: Arch Environ Health. 1971 Jun;22(6):677-865574010
Cites: Bull Physiopathol Respir (Nancy). 1970 Jul-Sep;6(3):637-595522013
Cites: Arch Environ Health. 1972 Mar;24(3):189-975059627
Cites: Arch Environ Health. 1972 May;24(5):358-635021120
Cites: Br J Ind Med. 1963 Oct;20:300-1214072622
Cites: Arch Environ Health. 1972 Jun;24(6):401-95031566
Cites: Arch Environ Health. 1975 Sep;30(9):435-91164045
Cites: Br J Ind Med. 1979 Feb;36(1):23-8444438
Cites: Ann N Y Acad Sci. 1979;330:1-9294160
Cites: Br J Ind Med. 1980 Feb;37(1):11-247370189
Cites: Arch Environ Health. 1972 Jun;24(6):388-4005031565
PubMed ID
7426477 View in PubMed
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Dust exposure and mortality in chrysotile mining, 1910-75.

https://arctichealth.org/en/permalink/ahliterature246109
Source
Br J Ind Med. 1980 Feb;37(1):11-24
Publication Type
Article
Date
Feb-1980
Author
J C McDonald
F D Liddell
G W Gibbs
G E Eyssen
A D McDonald
Source
Br J Ind Med. 1980 Feb;37(1):11-24
Date
Feb-1980
Language
English
Publication Type
Article
Keywords
Accidents
Aged
Asbestos - adverse effects
Asbestosis - mortality
Cerebrovascular Disorders - mortality
Dust
Employment
Environmental Exposure
Female
Follow-Up Studies
Heart Diseases - mortality
Humans
Lung Neoplasms - mortality
Male
Middle Aged
Mining
Neoplasms - mortality
Occupational Diseases - mortality
Quebec
Respiration Disorders - mortality
Smoking - complications
Time Factors
Abstract
We report a further follow-up of a birth cohort of 11 379 workers exposed to chrysotile. The cohort consisted of 10 939 men and 440 women, born 1891-1920, who had worked for at least a month in the mines and mills of Asbestos and Thetford Mines in Quebec. For all subjects, length of service and estimates of accumulated dust exposure were obtained, with a smoking history for the vast majority. Three methods of analysis, two based on the "man-years" methods, the other a "case-and-multiple-controls" approach, gave results consistent with one another and with previous analyses. By the end of 1975, 4463 men and 84 women had died. Among men, the overall excess mortality, 1926-75 was 2% at Asbestos and 10% at Thetford Mines, much the dustier region. The women, mostly employed at Asbestos, had a standardised mortality ratio (SMR) all causes, 1936-75) of 0.90. Analysis of deaths 20 years or more after first employment showed that in men with short service (less than five years) there was no discernible correlation with dust exposure. Among men employed at least 20 years, there were clear excesses in those exposed to the heaviest dust concentrations. Reanalysis in terms of exposure to age 45 showed definite and consistent trends for SMRs for total mortality, for lung cancer, and for pneumoconiosis to be higher the heavier the exposure. The response to increasing dose was effectively linear for lung cancer and for pneumoconiosis. Lung cancer deaths occurred in non-smokers, and showed a greater increase of incidence with increasing exposure than did lung cancer in smokers, but there was insufficient evidence to distinguish between multiplicative and additive risk models. There were no excess deaths from laryngeal cancer, but a clear association with smoking. Ten men and one woman died from pleural mesothelioma. If the only subjects studied had been the 1904 men with at least 20 years' employment in the lower dust concentrations, averaging 6.6 million particles per cubic foot (or about 20 fibres/cc), excess mortality would not have been considered statistically significant, except for pneumoconiosis. The inability of such a large epidemiological survey to detect increased risk at what, today, are considered unacceptable dust concentrations, and the consequent importance of exposure-response models are therefore emphasised.
Notes
Cites: Biometrics. 1969 Jun;25(2):339-555794104
Cites: Arch Environ Health. 1971 Jun;22(6):677-865574010
Cites: Arch Environ Health. 1972 Mar;24(3):189-975059627
Cites: Arch Environ Health. 1974 Feb;28(2):61-84809914
Cites: Arch Environ Health. 1974 Feb;28(2):69-714809915
Cites: Arch Environ Health. 1975 May;30(5):266-71130842
Cites: Br J Prev Soc Med. 1976 Dec;30(4):225-301009272
Cites: Int J Cancer. 1977 Sep 15;20(3):323-31903186
Cites: Prev Med. 1977 Sep;6(3):426-42333420
Cites: J Occup Med. 1977 Nov;19(11):737-40915568
Cites: Lancet. 1978 Mar 4;1(8062):484-976030
Cites: Br J Ind Med. 1964 Oct;21:304-714253230
PubMed ID
7370189 View in PubMed
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Latent periods in lung cancer mortality in relation to asbestos dose and smoking.

https://arctichealth.org/en/permalink/ahliterature246329
Source
IARC Sci Publ. 1980;(30):661-5
Publication Type
Article
Date
1980
Author
F D Liddell
Source
IARC Sci Publ. 1980;(30):661-5
Date
1980
Language
English
Publication Type
Article
Keywords
Adult
Age Factors
Air Pollutants, Occupational
Asbestos - adverse effects
Humans
Lung Neoplasms - mortality
Male
Middle Aged
Mining
Occupational Diseases - mortality
Quebec
Smoking
Time Factors
Abstract
Among 4463 deaths in a cohort of 10,939 men, born between 1891 and 1920, who had worked in the Quebec chrysotile mines and mills for at least a month, 244 were due to lung cancer. The interval from first asbestos exposure to death averaged 39.6 years; not unexpectedly, this interval was related to age at death and to age at first employment. However, the interval did not appear to be associated in any important way with other measures of exposure. All of the problems of interpretation pointed out by Enterline (1978) are acknowledged, and there is no guarantee of generalization to those exposed to asbestos in other circumstances. Nevertheless, among these 244 cases, there was no evidence to support the hypothesis that the latent period of asbestos-induced lung cancer depends on the dose.
PubMed ID
7228321 View in PubMed
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Exposing the "myth" of ABC, "anything but chrysotile": a critique of the Canadian asbestos mining industry and McGill University chrysotile studies.

https://arctichealth.org/en/permalink/ahliterature183190
Source
Am J Ind Med. 2003 Nov;44(5):540-57
Publication Type
Article
Date
Nov-2003
Author
David Egilman
Corey Fehnel
Susanna Rankin Bohme
Author Affiliation
Clinical Associate Professor, Brown University, Department of Community Health, Providence, Rhode Island, USA.
Source
Am J Ind Med. 2003 Nov;44(5):540-57
Date
Nov-2003
Language
English
Publication Type
Article
Keywords
Asbestos - adverse effects
Asbestos, Serpentine - adverse effects
Canada
Epidemiologic Research Design
Evaluation Studies as Topic
Humans
Mineral Fibers - adverse effects
Mining
Occupational Diseases - chemically induced
Occupational Exposure - adverse effects
Public Health
Respiratory Tract Diseases - chemically induced
Scientific Misconduct
Abstract
Beginning in the 1930s, the Canadian asbestos industry created and advanced the idea that chrysotile asbestos is safer than asbestos of other fiber types.
We critically evaluate published and unpublished studies funded by the Quebec Asbestos Mining Association (QAMA) and performed by researchers at McGill University.
QAMA-funded researchers put forth several myths purporting that Quebec-mined chrysotile was harmless, and contended that the contamination of chrysotile with oils, tremolite, or crocidolite was the source of occupational health risk. In addition, QAMA-funded researchers manipulated data and used unsound sampling and analysis techniques to back up their contention that chrysotile was "essentially innocuous."
These studies were used to promote the marketing and sales of asbestos, and have had a substantial effect on policy and occupational health litigation. Asbestos manufacturing companies and the Canadian government continue to use them to promote the use of asbestos in Europe and in developing countries. Am. J. Ind. Med. 44:540-557, 2003.
PubMed ID
14571518 View in PubMed
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Clinical measurement in Quebec chrysotile miners: use for future protection of workers.

https://arctichealth.org/en/permalink/ahliterature247778
Source
Ann N Y Acad Sci. 1979;330:23-9
Publication Type
Article
Date
1979
Author
M R Becklake
Source
Ann N Y Acad Sci. 1979;330:23-9
Date
1979
Language
English
Publication Type
Article
Keywords
Asbestos - adverse effects
Asbestosis - etiology - prevention & control
Humans
Male
Mining
Occupational Diseases - etiology - prevention & control
Public Health
Quebec
Abstract
There is a relationship between dust exposure, on the one hand, and serious disease and death, on the other, in chrysotile asbestos mine and mill workers of Quebec. Studies in current working populations indicate that prevalence of abnormality increases with increasing exposure. However, the relationship is weak and offers only a partial explanation of between-subject variability. In addition, there is no certain way to detect or predict change. Because of the relative nonspecificity of the health measurements examined and their poor relationship to exposure, control should be based on environmental monitoring, with biologic monitoring considered in a complementary role. This leaves the clinician with the dilemma of how best to advise the worker in whom questionable changes have been detected. At present, there appears little doubt that the decision must remain essentially clinical, based, on one hand, on all available information about the man, his job, and the plant or mine in which he works, from which an estimate of likely outcome must be made, and, on the other hand, on the social and human factors concerned, including the fact that removal from exposure does not necessarily prevent the appearance of abnormality.
PubMed ID
294176 View in PubMed
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Long-term mortality experience of chrysotile miners and millers in Thetford Mines, Quebec.

https://arctichealth.org/en/permalink/ahliterature247779
Source
Ann N Y Acad Sci. 1979;330:11-21
Publication Type
Article
Date
1979
Author
W J Nicholson
I J Selikoff
H. Seidman
R. Lilis
P. Formby
Source
Ann N Y Acad Sci. 1979;330:11-21
Date
1979
Language
English
Publication Type
Article
Keywords
Adult
Aged
Asbestos - adverse effects
Asbestosis - mortality
Epidemiologic Methods
Humans
Lung Neoplasms - mortality
Male
Mesothelioma - mortality
Middle Aged
Mining
Neoplasms - mortality
Occupational Diseases - etiology - mortality
Quebec
Risk
Abstract
Among a cohort of 544 men with at least 20 years of employment in chrysotile mining and milling at Thetford Mines, Canada, 16% of the deaths were from lung cancer and 15% from asbestosis. The excess over expected deaths from these causes account for 43 of 178 deaths in the group. The risk of death of asbestosis, at equal times fron onset of exposure, is very similar in miners and millers, factory workmen and insulators. The ratio of observed to expected deaths from lung cancer is similar in the miners and millers and factory workers, but higher in insulators. The risk of death of mesothelioma in miners and millers is decidedly less than the other two groups. The exact causes of the reduced risk in this category are not yet completely clarified.
PubMed ID
294161 View in PubMed
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29 records – page 1 of 3.