Asbestos-related abnormalities in school maintenance personnel

Our plain-English summary of Asbestos-related abnormalities in school maintenance personnel, by L.C. Oliver, N.L. Sprince, R. Greene (Annals of the New York Academy of Sciences, 1991).

The study

• Authors: L.C. Oliver, N.L. Sprince, R. Greene
• Journal: Annals of the New York Academy of Sciences
• Published: 1991;643:521-9
• Cited by: 3 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. 004440).

In plain English

This cross-sectional study surveyed Boston public school custodians in 1987 and 1988. Their schools had been surveyed for asbestos-containing materials in 1983. The article does not say which asbestos fiber types were in the schools. Analysis covered 120 white men; 57 reported no asbestos exposure outside school work. Chest X-rays showed pleural plaques in 40 men (33.3%), including 12 (21%) of those without outside exposure. Plaques were associated with asbestos exposure duration and latency. In men without outside exposure, plaques were also associated with years worked as a custodian. A restrictive breathing defect appeared in 18% overall and in 10 (17.5%) of those without outside exposure; it was associated with duration of exposure. One participant, who had also worked six months in a naval shipyard, later developed malignant mesothelioma. For comparison, the authors used a 0.7% plaque rate reported in Boston university workers after excluding 8 with prior occupational asbestos exposure. They concluded plaques were excessive, suggesting that in a subset they were attributable to school asbestos exposure. They noted voluntary participation, no unexposed comparison group, and possible exposure misclassification.

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 surveys (questionnaire, lung function tests, four-view chest radiographs, physical examination)
• Who was studied: Active or retired members of the Boston Public School Custodians Association with at least 20 years of service (1987) or at least 15 years (1988). Data were analysed for 120 white males; one other was excluded for amiodarone use. 102 of 197 eligible active custodians (51.8%) and 18 retired custodians were examined.
• Exposure: Work as custodians in Boston public school buildings with asbestos-containing materials (ACM), which were surveyed in 1983. Tasks included sweeping and dusting plaster or insulation dust, patching or removing pipe or boiler insulation, and boiler maintenance. The introduction mentions amphibole and serpentine fiber types in general, but the article does not identify which fiber types were present in the schools. 57 (47.5%) reported no asbestos exposure outside their custodial work (NOE); the others had outside exposure, mostly in shipbuilding, ship repair or building construction.
• Main results:
  • Pleural plaques were seen on chest radiographs in 40 of 120 subjects (33.3%); 39 cases were bilateral.
  • Among the 57 with no outside asbestos exposure, 12 (21%) had pleural plaques.
  • Controlling for smoking, pleural plaques in the whole group were significantly associated with duration of asbestos exposure (p = 0.0265) and latency (p = 0.0146). In the no-outside-exposure group they were associated with duration of work as a school custodian (p = 0.0155) and latency (p = 0.0163).
  • Three subjects (2.5%) had small irregular opacities of profusion grade 1/0 (ILO-1980); all three reported outside asbestos exposure.
  • A restrictive defect on lung function testing was found in 22 subjects (18.3%), including 10 (17.5%) of the no-outside-exposure group. It was associated with duration of asbestos exposure in both the total group (p = 0.0044) and the no-outside-exposure group (p = 0.0420), controlling for smoking.
  • Twelve subjects (10.1%) reported dyspnea of grade 2 or greater. Dyspnea was associated with duration of asbestos exposure (p = 0.0346), taking into account smoking and pleural plaques.
  • One participant later developed malignant mesothelioma. Besides 32 years as a school custodian, this participant had worked 6 months as a sheet-metal worker in a naval shipyard in 1942, and had pleural plaques on chest radiograph.
  • In 50 re-read film sets, pleural plaque prevalence was 38% using four views (with anterior oblique views) and 20% using two views (posteroanterior and lateral).
  • For comparison, the authors used previously reported data on 717 laboratory, maintenance and grounds personnel at a Boston university. Their plaque prevalence was 0.7% after excluding 8 with prior occupational asbestos exposure.
• The authors' conclusion: The authors concluded that pleural plaques in these custodians were in excess of background, taking into account the extra plaques detected by anterior oblique views. They suggested that in a subset the plaques were attributable to asbestos exposure in public schools.
• Limitations the authors state:
  • Participation was voluntary, which can introduce selection bias. Participants had longer custodial service than nonparticipants had seniority.
  • There was no unexposed comparison group from within the study.
  • Outside asbestos exposure status may have been misclassified. Where doubt could not be resolved, subjects were counted as having outside exposure.

Related studies

• Asbestos-related disease in custodial and building maintenance workers from a large municipal school district — J.R. Balmes, A. Daponte, et al. (1991)
• Asbestos-related disease in public school custodians — L.C. Oliver, N.L. Sprince, et al. (1991)
• Radiological abnormalities and asbestos exposure among custodians of the New York City Board of Education — S.M. Levin, I.J. Selikoff (1991)
• A radiographic survey of public school building maintenance and custodial employees — H.A. Anderson, L.P. Hanrahan, et al. (1992)
• Asbestos-associated pleural mesothelioma in school teachers: a discussion of four cases — D.E. Lilienfeld (1991)
• Asbestos in New York City public school buildings--public policy: is there a scientific basis? — R. Wilson, A.M. Langer, et al. (1994)

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