Asbestos disease in construction, refinery, and shipyard workers

Our plain-English summary of Asbestos disease in construction, refinery, and shipyard workers, by K.H. Kilburn, R.H. Warshaw (Annals of the New York Academy of Sciences, 1991).

The study

• Authors: K.H. Kilburn, R.H. Warshaw
• Journal: Annals of the New York Academy of Sciences
• Published: 1991;643:301-12
• Cited by: 4 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. 004851).

Summary of the article

The authors examined how common asbestosis was among construction, shipyard, refinery and production workers, and how shipyard work and cigarette smoking affected it. Workers were recruited through local unions if their first asbestos exposure was at least 15 years earlier and had lasted 5 years. From 1986 to 1989, one mobile medical team examined 8,749 workers. A single reader interpreted chest X-rays using ILO conventions. Asbestosis was defined as irregular opacities of profusion 1/0 or greater with occupational exposure and at least 15 years since first exposure. Pleural abnormalities were counted separately. Workers also had lung function tests and questionnaires. Asbestosis prevalence was 20% to 30% in nine of eleven trades with at least 100 workers. Boilermakers, pipefitters and sheet-metal workers, who handled asbestos directly, had no higher prevalence than bystander trades. Overall prevalence was 27.4% in construction trades and 36.6% in shipyard workers. It was 43.8% in oil refinery, 23.0% in aluminum refining, 21.6% in papermaking, 17.7% in fiberglass and 7.9% in copper smelter workers. In nearly all union groups, workers with shipyard experience had higher prevalence. Half of never-smokers had asbestosis at 75-80 years of age, compared with 60-65 years for current smokers. Mid-expiratory flow fell and air-trapping rose as opacity profusion increased, while total lung capacity did not decrease. The authors concluded that bystander and shipyard exposures cause substantial asbestosis and confound studies of other materials such as fiberglass.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

One mobile medical team examined 8,749 asbestos-exposed workers from 1986 to 1989. Union letters invited members and retirees first exposed at least 15 years earlier, with five years of exposure. One reader interpreted the chest X-rays. Asbestosis required irregular X-ray opacities of ILO profusion 1/0 or greater, plus an occupational exposure history and at least 15 years since first exposure. The authors wrote that nine of eleven construction trades with at least 100 workers had prevalence between 20% and 30%. Their table shows eight, with sheet-metal workers at 31.2% and sprinkler fitters and laborers lower. Trades handling asbestos directly had no higher prevalence than bystander trades. Prevalence was 27.4% in construction trades overall, 36.6% in shipyard workers, 43.8% in oil refinery workers and 7.9% in copper smelter workers. In union locals, workers with shipyard experience generally had higher prevalence. Half of never-smokers had asbestosis in the 75-80 age group, versus ages 60 to 65 among current smokers. Summarizing earlier papers, the authors reported reduced airflow and more air-trapping as X-ray changes increased. They inferred that major exposure occurred in contained airspaces.

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 screening survey (prevalence study) of union-recruited workers using one medical team and a uniform protocol. The pulmonary function and smoking sections also summarize the authors' earlier papers.
• Who was studied: 8,749 asbestos-exposed construction, shipyard, refinery and production workers (members and retirees) recruited through local unions in the United States and examined 1986-1989. Invitations went to those first exposed to asbestos 15 or more years before the study, with a duration of exposure of 5 years.
• Exposure: Occupational asbestos exposure in construction trades, shipyards, oil refining, aluminum refining, copper smelting, papermaking and fiberglass manufacturing, including bystander exposure. Fiber types and doses are not stated. Asbestosis was defined as irregular X-ray opacities of profusion 1/0 or greater, with a history of occupational exposure and 15 or more years since first exposure.
• Main results:
  • The authors stated that asbestosis prevalence was between 20% and 30% in nine of eleven trades with at least 100 workers, and that only sprinkler fitters and laborers had lower rates. Table 1 as printed shows eight trades in that range. Sheet-metal workers (144 workers) were at 31.2%, sprinkler fitters (217) at 17.0%, and laborers at 8.1% (site a, 138) and 16.3% (site b, 146).
  • Trades with the closest personal contact with asbestos (boilermakers, pipefitters, sheet-metal workers) had no higher prevalence than trades working at the same construction sites.
  • Overall prevalence was 27.4% in construction trades (5,112 workers) and 36.6% in shipyard workers.
  • Prevalence in other industries: oil refinery 43.8% (160 workers), aluminum refining 23.0% (670), papermaking 21.6% (171), fiberglass manufacturing 17.7% (175), copper smelter 7.9% (126).
  • In six large construction unions, workers with shipyard experience always had higher asbestosis prevalence, nearly double in several locals. For example, in Los Angeles (844 workers) prevalence was 43.6% with shipyard exposure versus 31.7% without.
  • In six shipyard unions, prevalence was also higher with shipyard experience. The exception was one local (Mobile 1: 60.0% without versus 44.9% with), which had only 15 non-shipyard workers.
  • Among examined workers, the age group in which 50% had asbestosis was significantly older for never-smokers (75-80 years) than for current smokers (60 to 65 years). The authors stated that never-smokers had less asbestosis and had it later, and that ex-smokers resembled current smokers.
  • Among 1,590 boilermakers, chronic bronchitis prevalence was 9.2% in nonsmokers, 20.9% in ex-smokers and 29.0% in current smokers. Abnormal pulmonary function test results were 19.0%, 24.4% and 28.1% respectively.
  • In never-smokers, mid-expiratory flow fell as X-ray profusion increased, while thoracic gas volume stayed between 100 and 110 percent of predicted. RV/TGV, a measure of air-trapping, rose from below 0.40 to almost 0.65 in men with moderately advanced asbestosis. In current smokers it rose from 0.43 to approximately 0.60. The authors stated that air-trapping was the earliest abnormality.
• The authors' conclusion: The authors inferred that major exposure to asbestos fibers occurred in contained airspaces. They concluded that proximity to asbestos handling did not materially affect prevalence after 15 or more years. They also concluded that shipyard exposure raises prevalence in many construction union locals and should be considered when comparing trades. They stated that asbestos exposure confounds studies of aluminum refining and fiberglass workers.
• Limitations the authors state:
  • Age distributions in the smoking analysis were truncated by the entry requirement of first exposure at least 15 years earlier.
  • The one exceptional shipyard local (Mobile 1) had only 15 non-shipyard workers.

Topics

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

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Chest X-Ray, Occupational Exposure, Pipefitter, Total Lung Capacity (TLC), Shipyard Exposure.

Related studies

• Surveillance of respiratory diseases among construction and trade workers at Department of Energy nuclear sites — J.M. Dement, L. Welch, et al. (2003)
• Asbestos-related disease among sheet-metal workers. Preliminary results of the National Sheet Metal Worker Asbestos Disease Screening Program — L.S. Welch, D. Michaels, et al. (1991)
• Airway obstruction in asbestos-exposed shipyard workers: with and without irregular opacities — K.H. Kilburn, R.H. Warshaw (1990)
• Asbestos disease in family contacts of shipyard workers — K.H. Kilburn, R. Lilis, et al. (1985)
• Does smoking cessation lead to weight gain? The experience of asbestos-exposed shipyard workers — T.J. Coates, V.C. Li (1983)
• Behavioral, attitudinal, and physiologic characteristics of smoking and nonsmoking asbestos-exposed shipyard workers — V.C. Li, Y.J. Kim, et al. (1983)

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