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N L Sprince

Publications and source records attributed to N L Sprince.

47 records · Page 3Linked to original sources
PubMed1986

A comparison of two definitions of abnormality on pulmonary outcome in epidemiologic studies.

Definition of abnormal outcome on lung function testing has not been well standardized. Observed test results have been compared with predicted values based on age, height, and sex in 2 ways: as percent of the predicted (PP) and in relation to limits established by the 95% confidence interval around the predicted (CI). The present study examines these 2 methods of comparison with respect to effect on pulmonary outcome in 377 railroad workers and 193 pipefitters exposed to asbestos. Using accepted PP and CI criteria to define abnormal test results, we classified subjects as restricted or obstructed or normal by each method. The proportion restricted or obstructed was higher (p = 0.0001) if definitions were based on PP rather than on CI: restriction, 12.5% by PP versus 7.2% by CI; obstruction, 18.4% by PP versus 16.0% by CI. Twenty-seven percent (n = 47) of those abnormal by PP were normal by CI. Independent indicators of disease were used to compare this discordant group with groups normal (n = 391) or abnormal (n = 129) by both criteria. The subjects in the discordant group were older, with more years of asbestos exposure, longer latency, and more pleural plaques (p less than 0.05). The occurrence of chronic bronchitis and dyspnea was similar to that in the abnormal group. In our study, the method of comparison had a significant effect on outcome; PP appeared a better measure of disease. Our findings suggest that age and underlying risk of the study population should be considered in selecting a method of comparison in epidemiologic studies of respiratory disease.

Humans↗
PubMed1985

Asbestos-related disease in railroad workers. A cross-sectional study.

A cross-sectional prevalence study of 377 railroad workers was carried out. The purpose was to investigate the prevalence of asbestos-related disease. We compared conventional with more recently adopted criteria for defining abnormal lung function. We compared the test results of those who performed reproducibly on spirometry with those who did not. Medical and occupational histories, flow-volume loops, and posteroanterior and lateral chest radiographs were obtained. Single-breath carbon monoxide diffusing capacity (DLCO) was measured, and chest auscultation was performed. Related to time since onset of exposure, pleural plaques occurred in 22.9%. There was radiographic evidence of interstitial disease in 1.6%. Reduced single-breath DLCO (12.4%), crackles (18.4%), and dyspnea (49.6%) were significantly associated with asbestos exposure. The prevalence of restriction and obstruction was 5.1 and 12.4%, respectively, but differed (p = 0.0001) with the definition criteria selected. The proportion with each of these abnormalities was higher in the nonreproducible group. That group was older, with more pleural plaques and chronic bronchitis. Railroad workers are a group at risk for asbestos-related disease. Extent of disease and assumptions about causality are likely to vary with definitions of normalcy and the use of reproducibility criteria.

Adult↗
PubMed1985

Natural killer cell activity in cigarette smokers and asbestos workers.

In order to evaluate the effects of cigarette smoking and asbestos exposure on cellular immunity, we tested a group of cigarette smokers and asbestos workers for natural killer (NK) activity in the peripheral blood. The mean NK activity in cigarette smokers was lower than in normal subjects (13.7 +/- 1.6 versus 29.0 +/- 3%; p less than 0.05). As a group, the mean NK activity for the asbestos-exposed group was also reduced compared with that of the nonsmoking control group (22.6 +/- 3.2%; p less than 0.05). When divided according to the smoking status, the asbestos workers who were nonsmokers or ex-smokers showed similar decreases in NK activity compared with normal subjects (19.5 +/- 6.2 and 21.2 +/- 4.5%, respectively; p less than 0.05). A subgroup of asbestos-exposed subjects who currently smoked showed no decrease in NK activity. The data show that NK activity is reduced in the peripheral blood of cigarette smokers and asbestos workers. The relatively normal NK activity found in asbestos workers who also smoked is unexplained. Impairment of NK activity is a potential mechanism for the increased incidence of infection and cancer in smokers and neoplasia in asbestos workers.

Adult↗
PubMed1985

Asbestos-related disease in plumbers and pipefitters employed in building construction.

Asbestos-related disease in a group of 153 plumbers and pipefitters employed in building construction was assessed by means of a cross-sectional prevalence study. Study methods were medical questionnaire, spirometry, measurement of diffusing capacity, physical examination of the chest, and chest roentgenogram. The major finding was bilateral pleural thickening in 28 (18.3%) of the participants. Unilateral pleural thickening was found in 12 subjects (7.8%). Small irregular opacities of profusion 1/0 or greater were found in 12 subjects (7.8%). Bilateral pleural thickening was associated with both age and time since first asbestos exposure, while unilateral pleural thickening was associated only with age. Decreases in forced vital capacity (percent predicted) were associated with duration of exposure. The most prevalent abnormality found was bilateral pleural thickening, which is more specific for asbestos exposure than is unilateral pleural thickening.

Adult↗
PubMed1984

Respiratory disease in tungsten carbide production workers.

We carried out a medical and environmental survey to evaluate respiratory disease at two tungsten carbide (TC) production plants. The study population of 290 subjects (19.2 percent of the total work force) was chosen to focus on those with the greatest potential exposures to cobalt, a binding agent which is probably the cause of interstitial fibrosis and airways disease in TC workers. We found peak air concentrations of cobalt exceeding 500 micrograms/m3 during many major steps in TC production. Nine subjects at plant A and two at plant B had interstitial infiltrates. Two of these nine from plant A had restriction (total lung capacity less than 80 percent of predicted). A lung biopsy specimen in one showed interstitial fibrosis. Two nonsmokers at plant A and one nonsmoker at plant B had obstructive defects. These results suggest that interstitial and obstructive lung disease occur in TC workers in association with elevated peak air concentrations of cobalt.

Adult↗
PubMed1978

Reversible respiratory disease in beryllium workers.

A medical and environmental survey was carried out in a beryllium extraction and processing plant in 1971, and a follow-up study was done in 1974. Peak air concentrations of beryllium of as much as 50 times the accepted peak limit value were found in the plant in 1971. Radiographic changes of interstitial disease were found in 31 workers, hypoxemia was found in 20, and in 11 workers a combination of hypoxemia and radiographic changes of interstitial disease was seen. Follow-up in 1974 showed that air concentrations had all decreased significantly, mainly because of improvements in engineering and ventilation in the plant. Improvement in hypoxemia and decreased alveolar-arterial O2 tension difference at rest ([A-a]DO2) were noted in 13 of the 20 men who had hypoxemia in 1971 and were available for follow-up. In addition, radiographic abnormalities of interstitial disease were reversed in some workers. Our results suggest that improvement in gas exchange and radiographic findings of interstitial disease occurs when peak air concentrations of beryllium are decreased. Our approach in combining environmental and medical screening in workers exposed to beryllium enabled us to identify persons with early changes, to detect reversible abnormalities, and to correlate air concentrations with the medical status of workers.

Adult↗
PubMedDate not supplied

Occupational injuries among workers with disabilities: the National Health Interview Survey, 1985-1994.

CONTEXT: As the baby boom generation ages, more people will be working with disabilities, but we have little information regarding how disabilities affect risk for occupational injury. OBJECTIVE: To test the hypothesis that work-limiting disabilities in general and hearing and visual impairments in particular are risk factors for occupational injuries. DESIGN: Retrospective cohort study. SETTING: The National Health Interview Survey (NHIS), 1985 to 1994. PARTICIPANTS: The 459827 participants in the NHIS from 1985 to 1994 who listed "working" as their primary activity, who were not farmers, and who were between 18 and 65 years of age. MAIN OUTCOME MEASURE: Occupational injuries in the year preceding the interview causing a residual impairment at the time of interview. RESULTS: After adjusting for occupation, self-employment, and age, occupational injury was associated with preceding work disability (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.19-1.56); blindness (OR, 3.21; 95% CI, 1.32-7.85); deafness (OR, 2.19; 95% CI, 1.17-4.12); hearing impairment (OR,1.55; 95% CI, 1.29-1.87); upper extremity impairment (OR, 1.46; 95% CI, 1.05-2.05); and arthritis (OR, 1.34; 95% CI, 1.07-1.68). Visual impairment was not associated with a significantly increased risk (OR, 1.37; 95% CI, 0.87-2.17). CONCLUSIONS: Workers with disabilities, especially sensory impairments, appear to have an elevated risk for occupational injury. Further research in the design and evaluation of improved workplace accommodations for workers with these disabilities is needed.

Accidents, Occupational↗