Pulmonary ventilatory function in talcosis of lung

Our plain-English summary of Pulmonary ventilatory function in talcosis of lung, by M. Kleinfeld, J. Messite, O. Kooyman, et al (Diseases of the Chest, 1964).

The study

• Authors: M. Kleinfeld, J. Messite, O. Kooyman, J. Shapiro
• Journal: Diseases of the Chest
• Published: 1964;46:592-8
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M nos. 002605, 002709).

In plain English

This study measured breathing (pulmonary ventilatory) function in 20 talc miners and millers. Each had worked with talc dust for more than ten years and had clinical and chest X-ray findings compatible with talc pneumoconiosis. Their dust was mostly talc mixed with other silicates (tremolite and anthophyllite) and a small amount of free silica. Mean exposure was 23.1 years, and every worker's weighted average exposure exceeded 50 million particles per cubic foot of air. All 20 were short of breath on exertion, and five were also short of breath at rest. Mean vital capacity was 66.6 per cent of predicted, mean indirect maximum breathing capacity 58.8 per cent, mean total lung capacity 74.5 per cent, and mean residual volume 99.9 per cent. Two workers had measurements in the normal range despite abnormal clinical and X-ray findings. The authors concluded that the changes indicated a restrictive and/or obstructive breathing disorder. They found no consistent correlation between the degree of impairment and the clinical, X-ray or exposure findings. They noted that the effect of free silica was difficult to ascertain and that diffusion capacity was not measured.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: clinical study (case series) of lung function testing in workers with talc pneumoconiosis; no comparison group of unexposed workers, results compared with predicted normal values
• Who was studied: 20 workers in talc mining and milling with more than ten years of exposure and clinical and X-ray findings compatible with talc pneumoconiosis; mean age 54.8 years (range 33 to 70); study by the Division of Industrial Hygiene, New York State; dates not given
• Exposure: dust predominantly of talc admixed with other silicates (tremolite and anthophyllite) and a small amount of free silica; mean exposure 23.1 years (range 11 to 40); weighted average talc dust exposure above 50 million particles per cubic foot (mppcf) for every worker: 50 to 100 mppcf in 11, above 100 mppcf in 9; free silica averaged 5.0 per cent of the talc ore in 22 samples
• Main results:
  • All 20 workers had exertional dyspnea, and in 5 dyspnea was also present at rest
  • 14 of the 20 workers had persistent minimal or moderate cough, productive in 9
  • In 18 workers, chest X-rays showed interstitial infiltration mainly in the mid and/or lower lung fields; in 2 it was more diffuse
  • Mean vital capacity for the group was 66.6 per cent of predicted; it was less than 60 per cent of predicted in 10 workers and above 80 per cent in 8
  • Mean one-second vital capacity was 66.5 per cent of actual vital capacity, against a predicted value of 79.1 per cent (plus or minus 7.2)
  • Mean indirect maximum breathing capacity was 58.8 per cent of predicted; it was less than 65 per cent in 13 workers
  • Mean maximum expiratory flow rate was 76.0 per cent of predicted; it was below 80 per cent in 13 of 19 persons
  • Mean residual volume for the 20 workers was 99.9 per cent of predicted; it was above 120 per cent in 5 and below 80 per cent in 6
  • Mean total lung capacity was 74.5 per cent of predicted; it was reduced (40.2 to 79.6 per cent of predicted) in 13 workers
  • Mean ratio of residual volume to total lung capacity was 129.6 per cent of predicted; it exceeded 120 per cent in 11 workers
  • Mean vital capacity and mean indirect maximum breathing capacity differed between workers with dyspnea at rest (5) and on exertion (15), statistically significant at p=0.05; one-second vital capacity and lung volumes did not differ significantly between these groups
  • Differences in mean one-second vital capacity and mean indirect maximum breathing capacity between smokers (14) and non-smokers (6) were not significant
  • Correlation coefficients between degree of pulmonary infiltration and vital capacity, one-second vital capacity, residual volume and total lung volume were -0.24, -0.08, -0.55 and -0.54
  • No consistent correlation was found between degree of lung impairment and duration or degree of talc dust exposure
  • In two workers (cases 15 and 20), lung function measurements were within normal range although clinical and X-ray findings were significantly abnormal
• The authors' conclusion: The authors concluded that the lung function changes indicate a restrictive and/or obstructive breathing disorder, and that overall there was no consistent correlation between the degree of impairment and the clinical, X-ray or environmental findings
• Limitations the authors state:
  • The degree to which free silica in the dust modified the clinical picture was difficult to ascertain
  • No diffusion capacity measurements were made

Topics

The National Library of Medicine indexes this study under subjects our site covers: Talc and vermiculite.

Related studies

• Effect of tale dust inhalation on lung function — M. Kleinfeld, J. Messite, et al. (1965)
• Talc pneumoconiosis: a report of six patients with postmortem findings — M. Kleinfeld, C.P. Giel, et al. (1963)
• Mixed pneumoconiosis: silicosis, asbestosis, talcosis, and berylliosis — G.J. Mark, C.B. Monroe, et al. (1979)
• Exposure to asbestos and mesothelioma of the pleura — P.B. Fowler, J.C. Sloper, et al. (1964)
• A case of lung adenocarcinoma complicated by pulmonary talcosis occurring in a patient employed in the confectionery industry — K. Kobayashi, N. Watanabe, et al. (2019)
• Relationship between chest X-ray findings and pulmonary function tests in dust workers — Y. Tonori, M. Niitsuya, et al. (2005)

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