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N L Sprince

Publications and source records attributed to N L Sprince.

At least 37 records · Page 2Linked to original sources
PubMed1996

The utility of preliminary surveys to detect the cause of acute metalworking fluid hazards.

This paper describes preliminary studies undertaken to optimize a later epidemiologic study, the aim of which was to identify a causative agent of adverse respiratory effects and dermatitis among production machinists. Two methods were used to rate coolant system hazards. The results of a voluntary plantwide questionnaire with an 18% participation rate showed that both dermatologic and respiratory symptoms were higher among machine operators than among maintenance or assembly workers, that symptoms were not more prevalent early in the week, and that dermatitis may be associated with smoking status; however, the questionnaire was not helpful in rating individual coolant system hazards. The hazard ratings provided by an in-plant expert panel were strongly associated with particular synthetic coolant containing an ethoxylated phenol; however, the resulting design for a later epidemiologic study could not be implemented due to changes in coolants used at the plant.

Chromatography, High Pressure Liquid↗
PubMed1996

Risk factors for occupational injuries among older workers: an analysis of the health and retirement study.

OBJECTIVES: This study examined risk factors for occupational injury among older workers. METHODS: We analyzed data on 6854 employed nonfarmers from the Health and Retirement Study (HRS), a population-based sample of Americans 51 through 61 years old. RESULTS: Occupational injuries were associated with the following: the occupations of mechanics and repairers (odds ratio [OR] = 2.27), service personnel (OR = 1.68), and laborers (OR = 2.18); jobs requiring heavy lifting (OR = 2.75); workers' impaired hearing (OR = 1.60) and impaired vision (OR = 1.53); and jobs requiring good vision (OR = 1.43). Self-employment was associated with fewer injuries (OR = 0.47). CONCLUSIONS: These results emphasize the importance of a good match between job demands and worker capabilities.

Accidents, Occupational↗
PubMed1995

Effect of recall period on the reporting of occupational injuries among older workers in the Health and Retirement Study.

Studies of injury morbidity often rely on self-reported survey data. In designing these surveys, researchers must chose between a shorter recall period to minimize recall bias and a longer period to maximize the precision of rate estimates. Using data from the Health and Retirement Study, which employed a recall period of 1 year, we examined the effect of the recall period on rates of occupational injuries among older workers as well as upon rate ratios of these injuries for nine risk factors. We fit a stochastic model to the occupational injury rates as a function of time before the interview and used this model to estimate what the injury rates would have been had we used a 4-week recall period. The adjusted occupational injury rate of 5.9 injuries per 100 workers per year was 36% higher than the rate based on a 1-year recall period. Adjustment for recall period had much less effect on rate ratios, which typically varied by < 10%. Our work suggests that self-reported surveys with longer recall periods may be used to estimate occupational injury rates and also may be useful in studying the associations between occupational injuries and a variety of risk factors.

Accidents, Occupational↗
PubMed1995

Low-dose methotrexate may cause air trapping in patients with rheumatoid arthritis.

Both rheumatoid arthritis (RA) and methotrexate (MTX) are reported to be associated with the development of pulmonary disease. To determine whether MTX enhanced the risk of developing abnormalities in pulmonary function in patients with RA, we prospectively studied 31 subjects (12 male, 19 female) with the diagnosis of classic RA for an average period of 4.4 yr (range, 1 to 5 yr). Each subject was placed on low-dose weekly MTX (mean 17 mg, range 2.5 to 40) for control of RA symptoms. Other medications included non-steroidal anti-inflammatory agents and prednisone if required for control of arthritis symptoms. No other immunosuppressive therapy was used. Each subject was evaluated by pulmonary function tests (PFT) and chest X-ray initially, and at 1, 2, 3.5, and 5 yr. Chest X-rays obtained initially and at the end of the study period were found to be normal. The percent predicted values for initial PFTs in the study group were within the normal range. From the beginning to the end of the observation period, the following mean changes in lung function were observed: 1.9% increase in TLC, 5.1% increase in residual volume (RV), 1.8% increase in FVC, 0.71% decrease in FEV1, 14.7% improvement in alveolar-arterial oxygen (A-aO2) difference, and a 12.7% increase in single-breath diffusing capacity (DLCO). To determine whether MTX (average dose, weekly dose, or cumulative dose) was significantly related to changes in pulmonary function, we used multivariate techniques to control for the initial measure of lung function while assessing the relationship between MTX and the subsequent measures of lung function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Occupational injuries: comparing the rates of male and female postal workers.

To compare the injury rates of male and female postal workers, the authors reanalyzed data on a cohort of 2,337 new postal employees in Boston, Massachusetts, hired between 1986 and 1989. The analysis controlled for potential confounding by age, race, smoking status, and drug use. Using Cox proportional hazards models with time-dependent variables, the authors found that, compared with men, women had an increased relative risk for occupational injuries in each of the three largest job classifications: letter carrier, letter-sorting machine clerk, and mail handler. The relative risks were not constant over time. For letter carriers and letter-sorting machine clerks, the increased risks for women were noted only during the first year of employment (relative risk (RR) = 1.93, 95% confidence interval (CI) 1.40-2.67) and RR = 2.60, 95% CI 1.31-5.15, respectively). For mail handlers, the increased risks for women were noted only after the first year of employment (RR = 2.13, 95% CI 1.09-4.15). As the percentage of women in the work force increases, these results suggest the need for further research to define sex-specific injury risks and to devise prevention strategies.

Accidents, Occupational↗
PubMed1992

T-cell alveolitis in lung lavage of asbestos-exposed subjects.

In sarcoidosis and idiopathic pulmonary fibrosis, it has been reported that lymphocyte proportions in lung lavage predict the subsequent clinical course. Recent evidence has suggested that lymphocytes are important in the alveolitis of asbestosis. We hypothesized that a greater relative proportion of T-lymphocytes in lung lavage of asbestos-exposed subjects is associated with immune activation and may predict the subsequent clinical course. We assessed lymphocyte subsets in lung lavage and peripheral blood (PB) of 97 asbestos-exposed subjects and 10 unexposed normal, using flow cytometry analysis of monoclonal antibody-treated cells. T-cell alveolitis was defined as follows: [%lymphocytes in lavage x %CD3 in lavage] greater than 2 SD above that product in normals. Eighteen subjects had T-cell alveolitis (group 1) and 79 did not (group 2). There were no significant differences between the groups in age, smoking status, duration of exposure, lung function results, or frequency of plaques or profusion greater than or equal to 1/0. Percent CD2 was higher in lavage of group 1 compared with group 2. There was a trend for higher %Ia in lavage of group 1 compared with group 2. These results identify a subgroup of asbestos-exposed subjects with T-cell alveolitis but no present excess of asbestos-related disease who may be at risk for future asbestos-related disease.

Adult↗
PubMed1991

Asbestos-related disease in public school custodians.

A cross-sectional prevalence study of 120 public school custodians was carried out. The purposes were 1) to investigate the prevalence of asbestos-related disease in a group of custodians at risk for asbestos exposure in public schools and 2) to determine the proportion with disease attributable to exposures in school buildings. Medical and occupational histories, flow-volume loops, and posterior-anterior, lateral, and anterior oblique (AO) chest radiographs were obtained. Single breath DLCO was measured and chest auscultation performed. Mean age of subjects was 57 years and mean duration of work as a custodian, 27 years. Fifty-seven (47.5%) had no known or likely exposure to asbestos outside of their work as a school custodian (NOE). Pleural plaques (PP) occurred in 40 (33%) of the total group and 12 (21%) of the group with NOE. Pulmonary restriction (FVC less than 80% predicted, FEV1/FVC% greater than or equal to 70) occurred in 22 (18%) of the total group and 10 (17%) of those with NOE. DLCO was lower in the group with restriction. Multivariate analysis revealed significant associations (p less than 0.05) between both PP and restriction and duration of asbestos exposure. AO radiographs increased PP detection by a factor of 1.9. Our results reveal PP prevalence in excess of background and pulmonary restriction in the study population, and indicate that PP are attributable to asbestos in schools. Findings with regard to pulmonary restriction need further investigation. Prudent management of asbestos in buildings is indicated for the prevention of related disease.

Adult↗
PubMed1991

Asbestos exposure and asbestos-related pleural and parenchymal disease. Associations with immune imbalance.

The study hypothesis was that asbestos exposure and asbestos-related pleural plaques and interstitial disease are associated with (1) immune imbalances favoring helper-inducer T-cell subsets in blood and bronchoalveolar lavage (BAL) and (2) T-lymphocyte accumulation in BAL. One hundred twenty-two asbestos-exposed subsets (AES), including 27 nonsmokers (NS), were evaluated and compared with 10 unexposed normal subjects. Data were collected on medical, smoking, and occupational histories, physical examination, spirometry, lung volumes, single-breath DLCO, chest films read by a "B" reader, and T-lymphocyte characterization in blood and BAL using flow cytometry analysis of monoclonal-antibody-treated cells. On average, AES were 47 yr of age and had 23 yr of asbestos exposure. Fifty-eight (48%) had pleural thickening, and seven (6%) had profusion greater than or equal to 1/0. In blood, asbestos-exposed NS had lower total and percent CD8 and lower total CD3 than did normal subjects. In BAL, asbestos-exposed NS had higher total CD3 than did normal subjects. Among AES, increased asbestos exposure was associated with increased percent CD8 in BAL and decreases in both percent lymphocytes and total CD8 in blood. Increase in CD4/CD8 ratio in BAL were associated with pleural thickening. In those seven with profusion greater than or equal to 1/0, there was increased percent CD4 in blood and decreased percent CD8 in BAL. These results suggest immune imbalance favoring helper-inducer T-cell subsets in association with asbestos exposure systemically and with pleural plaques in BAL.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Asbestos-related radiographic abnormalities in public school custodians.

A cross-sectional prevalence study of 120 public school custodians was carried out to investigate the prevalence of asbestos-related disease and to determine the proportion with disease attributable to asbestos exposures in school buildings. Medical and occupational histories, flow-volume loops, and posterior-anterior, lateral, and anterior oblique (AO) chest radiographs were obtained. Single breath DLCO was measured and chest auscultation performed. The present report describes radiographic abnormalities and associations with exposure. Mean age of subjects was 57 years and mean duration of work as a custodian, 27 years. Fifty-seven (47.5%) had no known or likely exposure to asbestos outside of their work as a school custodian (NOE). Pleural plaques (PP) occurred in 40 (33%) of the total group and 12 (21%) of the group with NOE. Multivariate analysis revealed significant associations (p less than 0.05) between PP and duration of asbestos exposure. The proportion with PP increased PP detection by a factor of 1.9. Our results reveal PP prevalence in excess of background in the study population and indicate that PP are attributable to asbestos exposure in schools in a subset with NOE. Prudent management of asbestos in buildings is indicated for the prevention of related disease.

Adult↗
PubMed1989

Pulmonary complications in lead miners.

We carried out a study to assess the prevalence of respiratory disease in lead miners and to investigate the roles of silica and lead. We used a questionnaire for symptoms and examinations for signs of respiratory disease, chest roentgenograms, and spirometric study in 45 lead miners. Six underwent bronchoscopy and transbronchial lung biopsy (TBB) and five lung lead analysis. Lung lead levels from five patients with no occupational lead exposure were obtained for comparison. Results showed restriction in five of 45 and reticulonodular opacities in 16 of 45 workers. Squamous metaplasia and other histopathologic changes were observed, although silicotic nodules were absent by TBB. Lung lead levels above those of control subjects were observed in four of five lead miners. These findings show that lead miners are at risk for lung disease. Although silica is a likely cause, elevated lung lead content found in these miners merits further investigation.

Adolescent↗
PubMed1988

Asbestos-related pleural plaques and lung function.

The present study examines the association between asbestos-related pleural plaques and lung function in a group of workers with occupational exposure to asbestos. Exposure, smoking, and respiratory histories, chest radiographs, flow-volume loops, and single breath DLCOs were obtained on 383 railroad workers. A score based on the ILO-1980 classification system was used to quantify the extent of plaquelike thickening. In order to eliminate potential confounders, we excluded from final analysis subjects with diffuse pleural thickening (n = 10) or small irregular opacities classified as profusion 0/1 or greater (n = 6) on chest radiograph. Definite pleural plaques were observed in 22.6%. The single breath DLCO was similar in the groups with and without plaques (p = 0.0550). Decrement in FVC and the occurrence of pulmonary restriction were associated with the presence of definite plaques (p = 0.0306 and 0.0431, respectively) and with quantitative pleural score (p = 0.0135 and 0.0126), controlling for duration of asbestos exposure and smoking. A test for trend revealed an association between level of diagnostic certainty (none, suspect, definite) for pleural plaques and these measures of lung function (p less than 0.02). Our findings reveal an association between asbestos-related pleural plaques and decrement in lung function as measured by FVC and criteria for pulmonary restriction.

Asbestosis↗
PubMed1988

Pulmonary function in beryllium workers: assessment of exposure.

The inhalation of beryllium causes a serious lung disease characterised by pronounced radiographic and functional impairments and occurs in workers engaged in the extraction and manufacture of the metal. This paper describes the beryllium exposure levels and refining processes in a large beryllium factory operating since the 1930s. Lifetime beryllium exposure histories were estimated for the 309 workers present at a health survey conducted in 1977. Beryllium exposure levels in the plant were high for many years, with some estimated exposure levels in excess of 100 micrograms/m3. As late as 1975, there were exposures to beryllium above 10 micrograms/m3 in some jobs. After about 1977, the plant was in compliance with the permissible exposure limit of 2.0 micrograms/m3. The median cumulative exposure in this cohort was 65 micrograms/m3-years and the median duration of exposure was 17 years. From these data a series of exposure parameters, functions of the exposure histories that characterise biologically important dimensions of exposure were calculated for each worker.

Beryllium↗
PubMed1988

Beryllium exposure and pulmonary function: a cross sectional study of beryllium workers.

A cross sectional study of 297 white male workers employed in a large beryllium plant was conducted to test the hypothesis that long term exposure to beryllium is associated with decrements in pulmonary function. Spirometric measurement of pulmonary function, chest radiographs, and arterial blood gas measurements were collected. After controlling for age, height, and smoking in multivariate regression models, decrements in FVC and FEV1 were found to be associated with cumulative exposure to beryllium in the period up until 20 years before the health survey. These decrements were observed in workers who had no radiographic abnormalities. The alveolar-arterial oxygen difference was associated with cumulative exposure in the 10 years immediately before survey, after controlling for age and smoking. These findings suggest that beryllium may have both short and long term pulmonary effects that are distinct from the classic forms of acute and chronic beryllium disease.

Adult↗
PubMed1988

Cobalt exposure and lung disease in tungsten carbide production. A cross-sectional study of current workers.

A cross-sectional study of 1,039 tungsten carbide (TC) production workers was carried out. The purposes were (1) to evaluate the prevalence of interstitial lung disease (ILD) and work-related wheezing, (2) to assess correlations between cobalt exposure and pulmonary disease, (3) to compare lung disease in grinders of hard carbide versus nongrinders, and (4) to evaluate the effects of new and previous threshold limit values for cobalt of 50 and 100 micrograms/m3. We obtained medical and occupational histories, flow-volume loops, single breath carbon monoxide diffusing capacity (DLCO), and chest radiographs. Time-weighted average cobalt levels were determined at every step in the production process. Work-related wheeze occurred in 113 participants (10.9%). Profusion greater than or equal to 1/0 occurred in 26 (2.6%) and interstitial lung disease (defined as profusion greater than or equal to 1M, FVC or DLCO less than or equal to 70%, and FEV1/FVC% greater than or equal to 75) in 7 (0.7%). The relative odds of work-related wheeze was 2.1 times for present cobalt exposures exceeding 50 micrograms/m3 compared with exposures less than or equal to 50 micrograms/m3. The relative odds of profusion greater than or equal to 1/0 was 5.1 times for average lifetime cobalt exposures exceeding 100 micrograms/m3 compared with exposures less than or equal to 100 micrograms/m3 in those with latency exceeding 10 yr. ILD was found in three workers with very low average lifetime exposures (less than 8 micrograms/m3) and shorter latencies. Grinders of hard carbide had lower mean DLCO than nongrinders, even though their cobalt exposures were lower.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbon Monoxide↗