Asbestos-related disease in custodial and building maintenance workers from a large municipal school district

Our plain-English summary of Asbestos-related disease in custodial and building maintenance workers from a large municipal school district, by J.R. Balmes, A. Daponte, J.E. Cone (Annals of the New York Academy of Sciences, 1991).

The study

• Authors: J.R. Balmes, A. Daponte, J.E. Cone
• Journal: Annals of the New York Academy of Sciences
• Published: 1991;643:540-9
• Cited by: 5 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. 004436).

Summary of the article

The authors examined whether occupational exposure to asbestos-containing materials (ACM) in public school buildings was sufficient to cause asbestos-related lung disease in school district workers. California OSHA required a large urban school district to set up a medical surveillance program for about 900 employees judged likely to have been exposed. Between May 1983 and June 1985, 673 participants completed a questionnaire on occupational, medical and smoking history and symptoms, a limited physical examination, spirometry, and chest X-rays. Each X-ray was read by three NIOSH-certified B readers using the 1980 ILO classification. Women and workers reporting asbestos exposure before district employment were excluded, leaving 422 men. Of the 315 men with at least 10 years of district employment, 36 (11.4%) had asbestos-related disease: 18 had parenchymal asbestosis only, 13 had pleural disease only, and 5 had both. Compared with the other 279 men, cases were older, had smoked more, had worked longer, and had lower mean percent predicted FEV1 (91.8 vs 104) and FVC (89.5 vs 100.2). Prevalence rose with length of employment. Current smokers had about twice the risk of never-smokers. Prevalence was 17.0% among plumbers and about 9% among custodial and building maintenance workers. The authors concluded that long-term occupational exposure to ACM in public schools can cause asbestos-related lung disease and that collecting mortality data for these workers should be a research priority.

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

This cross-sectional, descriptive study looked at 673 employees of a large urban school district who took part in an asbestos medical surveillance program from May 1983 through June 1985. The program used questionnaires, physical exams, breathing tests and chest X-rays read by three certified readers. Thirty-five workers diagnosed before May 1983 were left out. The main analysis covered 315 men who reported no asbestos exposure before working for the district and who had worked there at least 10 years. Of these, 36 (11.4 percent) had X-ray evidence of asbestos-related disease: 18 had lung-tissue changes (parenchymal asbestosis) only, 13 had pleural disease only, and 5 had both. These cases had lower breathing-test values than the others. Current smokers had about twice the risk of never-smokers. Plumbers had the highest rate (8 of 47), and custodial and building maintenance workers had about 9 percent (9 of 102). There was no unexposed comparison group and no air measurements. The authors concluded that long-term exposure to asbestos-containing materials in public schools is capable of causing asbestos-related lung disease.

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, descriptive study of medical surveillance data (questionnaire, limited physical examination, spirometry, chest X-rays classified by three B readers using the ILO 1980 system). The authors call it a preliminary report.
• Who was studied: 673 participants in the asbestos medical surveillance program of a large urban school district, examined May 1983 through June 1985. The program was required by CAL/OSHA. About 900 employees had been judged likely exposed and were required to take part. Females and those reporting asbestos exposure before district employment were excluded from later analyses, leaving 422 men; 315 of them had at least 10 years of district employment. Thirty-five workers diagnosed in the program's first two years were excluded.
• Exposure: Occupational exposure to dust from asbestos-containing materials (ACM) in school district buildings. At least 80 percent of about 750 buildings surveyed in 1980 had ACM. Likely exposure was determined mainly by job classification (plumbers, HVAC/sheet-metal workers, other construction trades, custodial/building maintenance, miscellaneous). No fiber type was measured. There were no industrial hygiene data, so length of district employment was used as a stand-in for duration of exposure.
• Main results:
  • Among the 315 men with no prior asbestos exposure and at least 10 years of district employment, 36 (11.4 percent) had radiographic evidence of asbestos-related disease.
  • Of the 315 men: 18 (5.7 percent) had parenchymal involvement only, 13 (4.1 percent) had pleural involvement only, and 5 (1.6 percent) had both.
  • The 36 cases were older than the 279 controls (mean 56 vs 48.8 years), smoked more (22.3 vs 12.4 pack-years) and had worked longer for the district (22.5 vs 19.9 years).
  • Cases had significantly lower mean percent of predicted lung function than controls: FEV1 91.8 vs 104, FVC 89.5 vs 100.2, FEF25-75 69.9 vs 86.8. FEV1/FVC was not significantly different (102.3 vs 103.7), and there was no evidence of large airway obstruction among the cases.
  • Among the 18 cases with asbestos-related pleural disease, mean FEV1 and FVC were significantly lower than in controls, but FEF25-75 was not.
  • Among the 422 men without prior exposure, mean percent of predicted FVC tended to fall as ILO profusion grade rose.
  • Among the 422 men, those with parenchymal disease (n = 25) had more mean pack-years (28.6) than those with pleural disease only (n = 15, 12.3) or controls (n = 382, 11.0). In logistic regression, current smokers had about twice the relative risk of never-smokers. Former smokers did not appear to be at greater risk than never-smokers.
  • Prevalence rose with length of employment. Parenchymal cases went from 1/51 (2.0 percent) at 5 years or less to 18/212 (8.5 percent) at more than 15 years; pleural cases went from 1/51 (2.0 percent) to 14/212 (6.6 percent). In logistic regression adjusted for age and smoking, the relative risk was about 1.3 times greater for more than 10 years of employment than for those just starting.
  • Case rates by the authors' exposure groups among the 422 men were:
• plumbers: 8/47 (17.0 percent)
• other construction trades: 16/154 (10.4 percent)
• custodial/building maintenance: 9/102 (8.8 percent)
• HVAC/sheet-metal workers: 3/47 (6.4 percent)
• miscellaneous: 4/72 (5.6 percent)

The authors suggested the relatively low HVAC/sheet-metal rate may be due at least in part to less smoking in that group.

• Custodial/building maintenance workers (custodians, plant managers, building engineers), whom the authors describe as mostly only indirectly exposed, had about a 9 percent prevalence of asbestos-related disease (9 of 102).
• The authors' conclusion: The authors concluded that long-term occupational exposure to asbestos-containing materials in public schools is capable of causing asbestos-related lung disease. They concluded that the disease prevalence found suggests the exposure of school custodial and building maintenance workers was considerable, and that collecting mortality data for such workers should be a research priority.
• Limitations the authors state:
  • The study was descriptive and had no unexposed control group for comparison.
  • No industrial hygiene data were available, so a dose-response relationship could not be examined directly; length of employment was used as a surrogate for exposure duration.
  • The cross-sectional design and the focus on respiratory morbidity rather than mortality meant the study could not address cancer risk.
  • The number of cases was relatively small, which limits the findings on lung function in pleural disease.
  • The five exposure groups were assigned arbitrarily from self-reported occupational histories.

Topics

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

Medical terms in this study, explained in our Lexicon: Occupational Exposure, Asbestos-Containing Material (ACM), OSHA, Spirometry, Chest X-Ray, NIOSH, ILO Classification, Asbestos Exposure.

Related studies

• A radiographic survey of public school building maintenance and custodial employees — H.A. Anderson, L.P. Hanrahan, et al. (1992)
• Asbestos-related abnormalities in school maintenance personnel — L.C. Oliver, N.L. Sprince, et al. (1991)
• Asbestos in New York City public school buildings--public policy: is there a scientific basis? — R. Wilson, A.M. Langer, et al. (1994)
• Airborne asbestos levels in school buildings in Italy — A. Campopiano, S. Casciardi, et al. (2004)
• Asbestos-related disease in public school custodians — L.C. Oliver, N.L. Sprince, et al. (1991)
• Mesothelioma among employees with likely contact with in-place asbestos-containing building materials — H.A. Anderson, L.P. Hanrahan, et al. (1991)

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