Pulmonary function of control and industrially exposed Nigerians in asbestos, textile, and toluene diisocyanate-foam factories

Our plain-English summary of Pulmonary function of control and industrially exposed Nigerians in asbestos, textile, and toluene diisocyanate-foam factories, by U.G. Oleru (Environmental Research, 1980).

The study

• Author: U.G. Oleru
• Journal: Environmental Research
• Published: 1980;23(1):137-48
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The pulmonary function of 120 non-industrially exposed Nigerians and of workers in an asbestos-cement factory, a cotton textile factory, and a TDI-foam factory was investigated. The pulmonary function of the control subjects was significantly (P < 0.001) higher than that of any of the control subgroups. The total particulate levels in the factories corresponded to the level of dust-generating activity. The highest suspended particulate level in the asbestos-cement factory was 18.3 mg.m-3 while the highest level in the textile factory was 14.94 mg. rnm3. The highest total respirable fiber content in the asbestos-cement factory was 6.63 f.cm-3 and this occurred in the cement and asbestos mixing section. It seemed that the greatest risk to pulmonary function for the exposed subjects resulted from exposure to cotton dust, however, a probable acute exposure to toluene diisocyanate among a subgroup that had an exposure duration of about a year produced the highest depression of lung function observed among the exposed subjects. It seems that the pulmonary function of the Nigerian “normal” population has not changed in a decade, after an apparent increase in industrialization. The pulmonary function equations developed in this study showed good predictability and the FEV1 and FVC values calculated from these equations closely matched those calculated from equations developed for other African subjects.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This study from the University of Lagos measured lung function in Nigerian factory workers and in a comparison group. Lung function meant two breathing measures, FEV1 and FVC, taken with a spirometer. The comparison group was 120 nonsmoking young men who were medical students and clerical workers. The workers came from three factories. An asbestos-cement factory used chrysotile and crocidolite asbestos: 18 workers came from its older, largely manual wing and 13 from a newer, mechanized wing. A cotton textile factory supplied 35 men, and a toluene diisocyanate (TDI) foam factory 50 men. None wore respirators. In the older asbestos-cement wing, respirable fiber levels were 6.63 fibers per cubic centimeter in mixing, 4.12 in grinding and 2.30 in processing. Every exposed group had significantly lower FEV1 and FVC than the controls, although the controls were also much younger. Textile workers had the lowest lung function. In the older asbestos-cement wing, mixing-section workers had the lowest. The author concluded that cotton dust seemed to pose the greatest threat. TDI machine operators showed the largest drop per year employed. No chest X-rays were possible, and the foam factory air was not sampled.

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 study comparing lung function (FEV1 and FVC by spirometry) of factory workers with an unexposed control group, with dust and fiber measurements in two of the factories
• Who was studied: Controls: 145 healthy young men (medical students and clerical workers), of whom the 120 nonsmokers were analyzed. Workers in Lagos, Nigeria: 18 of the 23 present in wing A and 13 of the 20 present in wing B of an asbestos-cement factory, 35 men from a cotton textile factory, and 50 men from a TDI-foam factory
• Exposure: Asbestos-cement manufacture using chrysotile and crocidolite asbestos (roofing sheets, pipes, joints), without respirators. The older wing A involved considerable manual work, and workers were grouped as mixing, processing and grinding. The comparison exposures were cotton dust and toluene diisocyanate
• Main results:
  • In asbestos-cement wing A, total respirable fiber levels were 6.63 f per cubic centimeter in the mixing section, 4.12 in grinding and 2.30 in processing
  • FEV1 and FVC of all exposure subgroups were significantly lower than those of the controls (P lower than 0.005)
  • Control nonsmokers (120) had mean FEV1 3.04 liters per second and mean FVC 3.76 liters
  • The control group was much younger than the exposure subgroups
  • Each textile subgroup had significantly lower FEV1 and FVC (P less than 0.01) than asbestos-cement wing A workers
  • Textile workers had the largest drop from expected FEV1, and asbestos-cement workers the next largest
  • Within asbestos-cement wing A, mixing-section workers, who had the highest dust and fiber levels, had the lowest lung function
  • TDI-foam machine operators, with a mean employment of 1.02 years, showed a drop of 27.74 (as printed) from expected FEV1 per year of mean duration of employment
• The authors' conclusion: The author concluded that cotton dust seemed to pose a more serious threat to lung function for these workers than any other agent. The author also concluded that the lung function of the 'normal' Nigerian population appeared not to have changed in a decade
• Limitations the authors state:
  • No chest X-ray examination could be done
  • No air sampling was done at the TDI-foam factory
  • The proportion of smokers among the controls was very small
  • The asbestos fiber analysis did not report standard deviations

Topics

Medical terms in this study, explained in our Lexicon: Asbestos-Cement, Respirable Fiber, FEV1.

Related studies

• Findings from high resolution computed tomography of the lung and pleura of symptom free workers exposed to amosite who had normal chest radiographs and pulmonary function tests — S. Neri, A. Antonelli, et al. (1994)
• Decreased lung function in long-term asbestos cement workers: a cross-sectional study — C.G. Ohlson, T. Rydman, et al. (1984)
• Relationship between chest X-ray findings and pulmonary function tests in dust workers — Y. Tonori, M. Niitsuya, et al. (2005)
• Lung function in insulation workers — J. Clausen, B. Netterstrøm, et al. (1993)
• The relation among pulmonary function, chest roentgenographic abnormalities, and smoking status in an asbestos-exposed cohort — L. Rosenstock, S. Barnhart, et al. (1988)
• Pulmonary function and pleural fibrosis: quantitative relationships with an integrative index of pleural abnormalities — R. Lilis, A. Miller, et al. (1991)

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