Prevalence of chronic respiratory disease. Asbestosis in ship repair workers

Our plain-English summary of Prevalence of chronic respiratory disease. Asbestosis in ship repair workers, by B.G. Ferris, M.V. Panadive, J.M. Peters, et al (Archives of Environmental Health, 1971).

The study

• Authors: B.G. Ferris, M.V. Panadive, J.M. Peters, R.L. Murphy, W.A. Burgess, H.P. Bendergrass
• Journal: Archives of Environmental Health
• Published: 1971;23(3):220-5
• Cited by: 20 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 no. 001358).

Abstract

Study of pipe coverers, pipe fitters, and welders at a ship repair yard indicated that pipe coverers had more changes in their lungs, as evidenced by examination of x-ray films, and slightly lower pulmonary function than the other two groups. All groups showed slightly lowered pulmonary function as compared with workers who did new-ship construction and were not exposed to asbestos. Aerometric measurement showed levels of asbestos that were, in general, lower than current threshold limit values. These findings reemphasize the need for control of asbestos in the work areas, as well as careful medical surveillance of workers exposed to asbestos.

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

In plain English

In 1968 the authors surveyed workers at a ship repair yard on US Navy premises. They compared 63 pipe coverers with pipe fitters and welders matched for age and years worked; 61 pipe coverers, 63 pipe fitters and 61 welders were seen. The men answered respiratory questions and had breathing tests, chest x-rays read without knowledge of their jobs, and chest examinations for crackling sounds (rales). Marked x-ray changes appeared only in pipe coverers, and questionable changes were also more common in them. Pleural calcification (11 cases) and "shaggy heart" outlines were significantly more common in pipe coverers. Pipe coverers more often reported shortness of breath; among the 83 men with acceptable diffusing-capacity tests, their diffusing capacity was lower. Simple breathing tests did not differ significantly between the three groups, though all were lower than unexposed shipyard workers from an earlier study. The authors noted they examined only men still working and that all groups may have had some exposure. They concluded that changes consistent with asbestosis occurred despite relatively low asbestos levels, possibly reflecting higher past exposures.

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 survey of currently employed workers, with matched comparison groups (pipe fitters and welders matched to pipe coverers) and workplace air sampling
• Who was studied: Workers at a ship repair yard surveyed in 1968, on US Navy premises. All 63 pipe coverers listed in the yard's personnel files were selected, each matched with a welder and a pipe fitter of about the same age and years at the yard. Table 1 lists 61 pipe coverers, 63 pipe fitters and 61 welders as seen.
• Exposure: Asbestos exposure in ship repair work, with pipe coverers as the most exposed group. Dust samples were taken from 1952 to 1966 (total dust counted, in million particles per cubic foot), and membrane-filter fiber samples were taken in a special three-month study. In 1965 fiber glass replaced amosite on major portions of the work. The authors stated that time-weighted averages may at times exceed the proposed limit of five fibers per milliliter in shipyard locations.
• Main results:
  • Marked chest x-ray changes were seen only in pipe coverers (Table 5: 3 men under 45 and 7 over 45). The difference from the other groups was significant at P less than 0.01.
  • Questionable x-ray readings occurred in all groups but were significantly more common in pipe coverers (P less than 0.05).
  • Pleural calcification, observed in 11 men, was significantly more common in pipe coverers (P less than 0.05).
  • Diaphragmatic calcification was more common among pipe coverers, but it occurred in only five men and the increase was not statistically significant.
  • "Shaggy heart" on x-ray was more common in pipe coverers than in pipe fitters or welders (P less than 0.01): 13 pipe coverers, two pipe fitters and no welders.
  • Shortness of breath was more common in pipe coverers than in the other two groups.
  • Forced vital capacity, FEV1 and peak flow did not differ significantly between the three occupational groups. Values in all three groups were lower than those of unexposed shipyard workers from an earlier study.
  • Measured diffusing capacity was lower in pipe coverers than in pipe fitters and welders. This applied to the men whose tests met the acceptance criteria: 83 of 186 subjects in Table 6.
  • Rales were heard in 6 of the 10 pipe coverers whose x-rays were consistent with moderately advanced asbestosis, compared with 12.1% of pipe fitters and welders together. Rales were also heard in 28.2% of pipe coverers whose x-rays were negative.
• The authors' conclusion: The authors concluded that changes consistent with asbestosis were seen despite relatively low asbestos levels in the yard, which may reflect higher past exposures. They said the study reemphasizes the need for continued control of asbestos exposure and careful medical surveillance of exposed workers.
• Limitations the authors state:
  • Only men still at work were examined, so diseased men who had retired or left could have been missed.
  • A retrospective study of earlier experience was not possible because of how records were kept.
  • Because different types of repair work were done at the same time, all groups may have been somewhat exposed, which could reduce differences between groups.
  • Good estimates of lifetime exposure could not be developed, because work at the yard was intermittent and fiber glass had recently been substituted.
  • Few air samples were taken during tearing out, the activity with high dust levels.
  • Respiratory resistance and volume-flow tests showed no differences, possibly partly because of the relatively small numbers.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis.

Medical terms in this study, explained in our Lexicon: Insulator, Threshold Limit Value (TLV).

Related studies

• Low exposure to asbestos. Gas exchange in ship pipe coverers and controls — R.L. Murphy, E.A. Gaensler, et al. (1972)
• Radiological evidence of asbestos disease among ship repair workers — I.J. Selikoff, W.J. Nicholson, et al. (1980)
• The relative importance of clinical, radiological and pulmonary function variables in evaluating asbestosis and chronic obstructive airway disease in asbestos workers — G.M. Regan, B. Tagg, et al. (1971)
• Parenchymal asbestosis due to primary asbestos exposure among ship-breaking workers: report of the first cases from Bangladesh — V. Muralidhar, M.F. Ahasan, et al. (2017)
• Occupational risk factors for chronic respiratory disease in a New Zealand population using lifetime occupational history — A. Hansell, R.E. Ghosh, et al. (2014)
• Change in prevalence of asbestos-related disease among sheet metal workers 1986 to 2004 — L.S. Welch, E. Haile, et al. (2007)

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