Radiological abnormalities and asbestos exposure among custodians of the New York City Board of Education

Our plain-English summary of Radiological abnormalities and asbestos exposure among custodians of the New York City Board of Education, by S.M. Levin, I.J. Selikoff (Annals of the New York Academy of Sciences, 1991).

The study

• Authors: S.M. Levin, I.J. Selikoff
• Journal: Annals of the New York Academy of Sciences
• Published: 1991;643:530-9
• Cited by: 11 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. 004438).

Abstract

Six hundred sixty custodians employed by the New York City Board of Education underwent examination from 1985 through 1987 for asbestos-related disease and other general medical conditions by the clinical staff of the Division of Environmental and Occupational Medicine of the Mount Sinai School of Medicine of the City University of New York. Two-thirds of the men (no women were examined) were 20 or more years from onset of any custodial work, with 44% having had at least 20 years of employment as custodial workers in New York City Board of Education schools. Twenty-four percent had begun custodial work in buildings 30 or more years earlier. Findings among them were of particular interest since asbestos-related disease might forecast what might be expected among school custodians with less seniority. Since the Board of Education, in selecting custodians for examination, had chosen only custodians currently employed, the study group comprised men still working in the school system. These, then, represented a "survivor population" (4% had retired between the time of enrollment in the study and the date of examination, and only one of the seventeen retirees had left work owing to disability). Although a considerable amount of clinical information was obtained, abnormalities on chest X-ray consistent with asbestos-induced scarring were used as the key index of disease resulting from exposure to asbestos. Since scarring of the lung tissue or lining of the lung or chest wall (pleura) may be present but undetectable on standard chest radiographs (a relatively insensitive diagnostic technique), the prevalence of abnormality on X-ray film represents a conservative estimate of the actual burden of scarring lung disease in the group. Such changes are indicative of previous asbestos exposure, however, and provide evidence of an increased risk of later asbestos-related malignancy. Overall, abnormalities on chest X-ray consistent with asbestos-related scarring were found in 28% of the men examined. The expected relationship of increasing prevalence of radiographic changes with increasing time since onset of exposure in buildings was demonstrated; among those with 35 or more years since beginning custodial work, 39% had abnormal films. This is evidence that custodial workers as a group have had asbestos exposure in the past, as reflected also in the work histories obtained at the time of examination. Eighty-four percent reported that they themselves removed asbestos-containing materials in the course of their work. Eighty-nine percent had been present in the work area during asbestos abatement projects in the schools in more recent years.(ABSTRACT TRUNCATED AT 400 WORDS)

In plain English

This clinical survey examined 660 male New York City Board of Education custodians at Mount Sinai Medical Center from 1985 through 1987. Of 764 invited, 86% took part. Most reported working directly with asbestos-containing materials (89%), and 84% said they had removed them. No fiber types were named. X-ray changes consistent with asbestos-related scarring appeared in 28% of all men. Among men with abnormal X-rays, nearly equal numbers had lung-tissue and pleural (lung lining) scarring. Among men 35 or more years from starting custodial work, 39% had such changes. Among 247 men who reported no occupational or shipboard asbestos exposure outside the schools, 27% had such changes (the summary section gives 28%). In this group, 53% of those who started 35 or more years earlier had abnormal X-rays, versus 25% of those starting 34 years ago or less. No particular work activity was linked to notably more abnormality. The authors concluded the custodians had been significantly exposed to asbestos in the past. They noted the men were a currently employed "survivor group" and that X-rays likely underestimate scarring.

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 clinical survey (medical examinations including chest X-rays), conducted 1985 through 1987 at Mount Sinai Medical Center
• Who was studied: 660 men (no women) employed as custodians by the New York City Board of Education, out of 764 invited (participation rate 86%). Those invited were currently employed custodians chosen mainly for longest duration of Board of Education employment.
• Exposure: Asbestos-containing materials in school buildings. Custodians reported mixing, removing or fixing such materials, and being present during asbestos abatement projects. 89% reported working directly with asbestos-containing materials. No fiber type was named. Many also reported asbestos exposure in other work, such as merchant marine, shipyard and insulation work.
• Main results:
  • Among all 660 custodians, 28% had chest X-ray abnormalities consistent with asbestos-related scarring: parenchymal only 75 (11%), pleural and parenchymal 30 (5%), pleural only 77 (12%).
  • Among men with abnormalities, nearly equal numbers had parenchymal (lung tissue) and pleural scarring.
  • Among all custodians with 35 or more years since beginning custodial work, 39% had abnormal films.
  • Among all custodians 30 or more years since beginning custodial work, 37% had asbestos-related abnormality on X-ray.
  • Among the 18 men 40 or more years since beginning custodial work, 11 (61%) had findings consistent with asbestos-induced scarring.
  • 84% of the custodians reported that they themselves removed asbestos-containing materials at work.
  • Where abatement had taken place in their schools, 89% of custodians reported being present in the area where the work was done.
  • 247 men reported no occupational or shipboard asbestos exposure other than in the schools. The results section reports 27% abnormal X-rays in this group (68 of 247 in Table 11); the summary section reports 28%.
  • In the school-only exposure group, 53% of those who began custodial work 35 or more years earlier had abnormal chest X-rays, compared with 25% of those 34 years or less from beginning such work.
  • No particular work activity (mixing, fixing or removing asbestos) was associated with a markedly higher prevalence of X-ray abnormality.
  • Among custodians exposed only in schools, being present during or helping with abatement had no detectable influence on the prevalence of X-ray abnormality.
• The authors' conclusion: The authors concluded that the data are consistent with New York City Board of Education school custodians having been significantly exposed to asbestos in the past in the course of their work.
• Limitations the authors state:
  • Only currently employed custodians were eligible, so the group was a 'survivor group' healthy enough to keep working.
  • Standard chest X-rays are relatively insensitive, so the prevalence found is a conservative estimate of scarring.
  • Only 18 men were 40 or more years since starting custodial work, too few for reliable conclusions about the most senior workers.
  • Exposures during abatement, which began in the latter 1970s, would not be expected to produce visible X-ray scarring until the latter 1990s at the earliest.
  • Asbestos exposures outside school custodial work may have contributed to the overall exposure burden in over 60% of those examined.

Topics

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Chest X-Ray, Pleura, Asbestos-Containing Material (ACM), Abatement.

Related studies

• 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)
• Asbestos-related disease in public school custodians — L.C. Oliver, N.L. Sprince, et al. (1991)
• Asbestos-containing materials in New York City buildings — P. Lundy, M. Barer (1992)
• Asbestos exposure and radiological abnormalities among maintenance and custodian workers in buildings with friable asbestos-containing materials — M. Matrat, J.C. Pairon, et al. (2004)
• Asbestos-related disease in custodial and building maintenance workers from a large municipal school district — J.R. Balmes, A. Daponte, et al. (1991)

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