Cigarette smoking and small irregular opacities

Our plain-English summary of Cigarette smoking and small irregular opacities, by W. Weiss (British Journal of Industrial Medicine, 1991).

The study

• Author: W. Weiss
• Journal: British Journal of Industrial Medicine
• Published: 1991;48(12):841-4
• Cited by: 28 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

A survey of chemical workers by chest roentgenograms was designed to determine whether exposure to acrylic dust and/or cigarette smoking was associated with diffuse abnormalities suggestive of pneumoconiosis. The films were examined without knowledge of dust exposure or smoking habits. The International Labour Office (ILO) classification and standard films were used. Workers with exposure to asbestos were excluded. There was no relation between prevalence of abnormalities and exposure to dust. Among 181 workers 28 had s and/or t small irregular opacities with profusion of 0/1 (23), 1/0 (three), or 1/1 (two). These findings were present in 20% of smokers compared with 2.2% of non-smokers. The prevalence increased with increasing age to 31.6% among smokers aged 50-64. Prevalence was 10% among ex-smokers of cigarettes. Among current cigarette smokers, prevalence was 5.3% in those who smoked less than one pack per day, 31.3% in heavier cigarette smokers, and 52.9% in 17 heavy cigarette smokers aged 50-64. Profusions of 0/1 and 1/0 are classified as "suspect" pneumoconiosis according to the ILO guidelines. The data in this study indicate that such abnormalities are directly related to age and smoking habits among workers not exposed to hazardous dust.

In plain English

This study examined chest X-rays of 181 men at a chemical plant, 100 exposed to acrylic dust and 81 unexposed, matched by age, year hired and smoking habit. Workers with known asbestos exposure were excluded. The author read the films without knowing dust exposure or smoking habits, using the 1980 International Labour Office (ILO) classification, and recorded small irregular opacities, which can suggest pneumoconiosis. Twenty-eight films showed them at profusion 0/1 or greater (23 at 0/1, three at 1/0, two at 1/1). They appeared in 1 of 46 non-smokers (2.2%) and 27 of 135 smokers (20%). All five readings of 1/0 or 1/1 were in smokers. Among smokers, prevalence rose with age to 31.6% at ages 50 to 64. Among current cigarette smokers, the finding was seen in 1 of 19 light smokers, in 15 of 48 heavy smokers (a pack or more daily), and in 9 of 17 heavy smokers aged 50 to 64. The author concluded the abnormalities were directly related to age and smoking habits in workers not exposed to hazardous dust. Only one reader examined the films.

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: Cross-sectional chest X-ray survey drawn from a controlled comparison of acrylic dust-exposed and unexposed workers. Films were read blind using the 1980 ILO classification.
• Who was studied: 181 men at a chemical plant: 100 exposed to acrylic dust and 81 unexposed, matched by age, year hired and smoking habit. Workers with known asbestos exposure were excluded. Complete smoking histories were available for 163. There were 46 non-smokers and 135 smokers. Place and dates are not stated.
• Exposure: Cigarette smoking: non-smokers, ex-smokers, and current light (less than one pack per day) or heavy (one pack or more per day) smokers, plus a miscellaneous group including pipe or cigar smokers. Acrylic dust exposure was also compared. Asbestos-exposed workers were excluded.
• Main results:
  • 28 of 181 films had small irregular opacities (type s and/or t) at profusion 0/1 or greater: 23 at 0/1, three at 1/0, two at 1/1.
  • Non-smokers: 1 of 46 (2.2%). Smokers: 27 of 135 (20%). The difference was statistically highly significant (p less than 0.005).
  • All five films with profusion of 1/0 or 1/1 were in smokers.
  • Among smokers, prevalence rose with age, reaching 18 of 57 (31.6% in Table 3, rounded to 32% in the text) in those aged 50 to 64.
  • Current cigarette smokers: 1 of 19 light smokers (5%) had the finding, compared with 15 of 48 heavy smokers (31%).
  • Heavy current cigarette smokers aged 50 to 64: 53% of 17 men (9 of 17, 52.9% in Table 4).
  • Ex-smokers of cigarettes: 5 of 50 (10%).
  • Opacities at profusion 0/1 or greater were found in 16% of the acrylic dust-exposed group and 15% of the unexposed group.
• The authors' conclusion: The author concluded that these abnormalities, which ILO guidelines class as 'suspect' pneumoconiosis at profusions 0/1 and 1/0, are directly related to age and smoking habits among workers not exposed to hazardous dust.
• Limitations the authors state:
  • Only one reader (the author) read the films, so the study does not take into account variation between readers.

Topics

Medical terms in this study, explained in our Lexicon: Pneumoconiosis, Habit.

Related studies

• Cigarette smoke, asbestos, and small irregular opacities — W. Weiss (1984)
• Effect of tobacco smoking on the presence of asbestosis at postmortem and on the reading of irregular opacities on roentgenograms in asbestos-exposed workers — A. Kraut, J. Godbold, et al. (1989)
• The effect of cigarette smoking on the detection of small radiographic opacities in inorganic dust diseases — P.D. Blanc, G. Gamsu (1988)
• Effect of tobacco smoking on the presence of asbestosis at postmortem and on the reading of irregular opacities on roentgenograms in asbestos-exposed workers — E. Hnizdo, G.K. Sluis-Cremer (1988)
• Progression of irregular opacities in asbestos miners — G.K. Sluis-Cremer, E. Hnizdo (1989)
• Factors influencing the reading of small irregular opacities in a radiological survey of asbestos miners in South Africa — G.K. Sluis-Cremer, P.A. Hessel, et al. (1989)

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