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Biomedical subjects

M M Finkelstein

Publications and source records attributed to M M Finkelstein.

62 records · Page 4Linked to original sources

Radiographic abnormalities among asbestos-cement workers. An exposure-response study.

We studied the development of small irregular opacities and bilateral pleural thickening in a longitudinal study of 181 asbestos-cement workers. The relationships between the 32-yr risks of developing abnormalities and cumulative exposure to asbestos dust could be described with log-normal curves. Smokers had higher risks of both abnormalities than did nonsmokers. In this cohort, men leaving asbestos exposure had a risk of radiographic progression similar to men continuing in exposure, and men with abnormal radiographs had higher mortality rates than did men with normal ones.

Asbestos↗

Mortality among employees of an Ontario asbestos-cement factory.

Mortality among 535 asbestos-exposed and 205 nonexposed employees of an asbestos-cement factory was investigated. In the period beyond 20 yr from first exposure, the exposed workers had standardized mortality ratios of 175 for all causes of death, 370 for all malignancies, 480 for lung cancer, 240 for gastrointestinal cancers, and 17 deaths from mesothelioma; the factory control subjects had mortality rates similar to the general population. The cell-type distribution of the lung cancers was similar to that occurring in middle-aged smokers. Cumulative fiber exposures were calculated for the production workers, and mortality rates for the asbestos-associated malignancies were found to have significant trends with exposure. Exposure-related lung cancer risks were noted, with a large margin of uncertainty, to be similar to those observed in an American study of manmade mineral fiber workers.

Adenocarcinoma↗

Mortality among long-term employees of an Ontario asbestos-cement factory.

Mortality was studied among a group of 328 employees of an Ontario asbestos-cement factory who had been hired before 1960 and who had been employed for a minimum of nine years. The group of 87 men who had worked in the rock wool/fibre glass operations, or who had been otherwise minimally exposed to asbestos, had mortality rates similar to those of the general Ontario population, while the group of asbestos-exposed employees had all-cause mortality rates double those of the Ontario population, mortality rates due to malignancies five times higher than expected, and deaths attributed to lung cancer eight times more frequent than expected. According to the best evidence available, 10 of 58 deaths among the production workers were due to malignant mesothelioma and 20 to lung cancer. The men dying of mesothelioma were younger than the men dying of lung cancer with mean ages at death of 51 and 64 years respectively. An exposure model was constructed on the basis of the available air sampling data, and individual exposure histories were calculated. These exposure histories were used to investigate the exposure-response relationships for asbestos-associated malignancies.

Adult↗

Asbestosis in long-term employees of an Ontario asbestos-cement factory.

We studied the development of compensable (certified) asbestosis among the 201 workers at an asbestos-cement factory who were first exposed to asbestos dust prior to 1980 and who had been employed at least 15 yr. By July 1980, 39% of the production workers and 20% of the maintenance workers had developed a compensable chest disability; the "latent interval" generally exceeded 20 yr. Workers with asbestosis were found to have markedly elevated mortality rates with deaths caused by malignancies and respiratory disease being primarily responsible. We combined the limited air sampling data available with individual work histories to calculate 18-yr cumulative fiber exposures. The cumulative probability of certification was related to the cumulative exposures and the exposure-response relationship was found to be sigmoidal in form.

Asbestosis↗

Mortality among workers exposed to carbon disulfide.

Mortality experience was investigated at a plant in Ontario that produced viscose rayon, with carbon disulfide as a main raw material. Work-history records for 279 deceased workers at the plant (plant A) were obtained and compared with those for 511 deceased workers at a pulp and paper plant in the same city (plant B). In a proportional mortality analysis, using as a reference the general population of Ontario, at both plants there were fewer deaths from ischemic heart disease than expected (the proportional mortality ratios [PMRs] were 83 at plant A and 95 at plant B) but more deaths than expected from cerebrovascular disease (PMRs were 115 at plant A and 149 at plant B). In a subgroup of plant A workers who had been employed in high-carbon-disulfide exposure areas, deaths from ischemic heart disease were less than expected (PMR = 82), particularly among those who worked in these areas for more than 5 y. Most deaths occurred among those aged 65 y or more. Mortality from strokes, however, was greater than expected (PMR = 207, p < .05); the excess was confined to workers who died at age 65 y or older (PMR = 229, p = .01). Proportional mortality from strokes was also increased in the pulp workers among those who died at age 65 y or older (PMR = 153). In a case-control analysis, the risk of ischemic heart disease at plant A was slightly less than at plant B (odds ratio (OR] = 0.92, 95% confidence interval [CI] = 0.60-1.42), with no association between risk and years worked in high-carbon-disulfide areas (OR/y = 0.99, 95% CI = 0.94-1.03). Among those who died at age 65 y or older, the risk of stroke in the high-exposure subgroup was (a) increased significantly, compared with other plant A workers (OR = 4.92, 95% CI = 1.66-14.65); and (b) increased slightly, compared with plant B workers (OR = 1.37, 95% CI = 0.83-2.26). These results suggested an unusually low risk of strokes among other plant A workers. The risk of stroke was associated with years in high-carbon-disulfide areas (OR/y = 1.03, 95% CI = 0.96-1.1 0). The observed increase in proportional mortality from strokes may represent a chance finding, but a causal role for exposure cannot be excluded.

Age Factors↗

Exposure estimation in the presence of nondetectable values: another look.

A common problem faced by industrial hygienists is the selection of a valid way of dealing with those samples reported to contain nondetectable values of the contaminant. In 1990, Hornung and Reed compared a maximum likelihood estimation (MLE) statistical method and two methods involving the limit of detection, L. The MLE method was shown to produce unbiased estimates of both the mean and standard deviation under a variety of conditions. That method, however, was complicated, requiring difficult mathematical calculations. Two simpler alternatives involved the substitution of L/2 or L/square root of 2 for each nondetectable value. The L/square root of 2 method was recommended when the data were not highly skewed. Although the MLE method produces the best estimates of the mean and standard deviation of an industrial hygiene data set containing values below the detection limit, it was not practical to recommend this method in 1990. However, with advances in desktop computing in the past decade the MLE method is now easily implemented in commonly available spreadsheet software. This article demonstrates how this method may be implemented using spreadsheet software.

Air Pollutants, Occupational↗

Obesity, cigarette smoking and the cost of physicians' services in Ontario.

BACKGROUND: This report uses population-based individual-level data to compute direct estimates of the costs of physicians' services in Ontario in relation to Body Mass Index (BMI) and smoking. METHODS: Subjects were 2,170 respondents to the National Population Health Survey who approved linkage to the Ontario Health Insurance Plan. RESULTS: The mean per capita cost of physicians' services in Ontario increased by $8.90 (95% CI: $1.90-$15.60) for each unit increase in BMI and by $1.75 (95% CI: $0.11-$3.40) for every year of daily smoking. The annual attributable cost of smoking and overweight among residents of Ontario, aged 40-79, was estimated at $275,000,000. CONCLUSIONS: Overweight and smoking are responsible for large costs to the health care system. The cost of public health initiatives could be easily recovered if they were successful in making only moderate changes to the levels of smoking and body weight in the population.

Adult↗