Indoor asbestos pollution: application of hazard criteria

Our plain-English summary of Indoor asbestos pollution: application of hazard criteria, by R.N. Sawyer (Annals of the New York Academy of Sciences, 1979).

The study

• Author: R.N. Sawyer
• Journal: Annals of the New York Academy of Sciences
• Published: 1979;330:579-86
• Cited by: 6 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. 004379).

Abstract

Asbestos contamination of relatively contained environments within structures can occur under many conditions and in association with various activities. Such contamination persists and can potentially expose all structure users. The more significant contamination levels are associated with disturbance of friable asbestos-containing materials, although bonded material is also capable of fiber dissemination under special conditions. Application of occupational government standards for limitation of exposure, both presently in force and proposed or recommended, indicates that levels found in some situations exceed those considered potentially carcinogenic.

In plain English

This article, by an author at Yale Health Service, gathered air-sampling results for asbestos fibers inside buildings and compared them with workplace exposure limits. The data came from surveillance and reenactment studies, mostly in nonoccupational settings such as apartment buildings, offices, schools and private homes. Fibers were counted by standard phase-contrast optical microscopy. Results were grouped by source (friable or bonded asbestos-containing material) and by ten activity classifications, including quiet conditions, maintenance, custodial work, renovation, vandalism and removal. Against the 1976 OSHA limits, some routine maintenance and custodial activities could exceed the 2.0 fibers per cubic centimeter time-weighted average. Occasional removal, renovation and vandalism exceeded the 10 fibers per cubic centimeter ceiling. Under the stricter 1975 proposed OSHA and 1977 NIOSH recommended limits, more activities fell within the hazardous range. Only quiet and some nonspecific routine conditions stayed outside the NIOSH limits. The author noted that the counting method is not specific for asbestos and that the limits were written for workers. The author concluded that levels in some situations exceeded those considered potentially carcinogenic.

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: Compilation of indoor air-sampling data (surveillance and reenactment studies, several by the author), with the fiber levels compared against occupational exposure standards; not an epidemiological study of disease
• Who was studied: Airborne asbestos fiber measurements taken in numerous structures under variable activity conditions, usually nonoccupational settings such as apartment buildings, offices, schools and private homes; total sample numbers, locations and dates are not stated in the text
• Exposure: Airborne fibers from friable asbestos-containing material (for example sprayed-on material and pipe lagging) and from bonded material (cementitious material, tiles, concrete, taping compound), during activities from quiet conditions to dry removal. Fiber types (such as chrysotile or amphiboles) are not specified. Levels were measured by phase-contrast optical microscopy in fibers per cubic centimeter.
• Main results:
  • Compared with the present (1976) OSHA limits (2.0 fibers per cubic centimeter time-weighted average, 10.0 ceiling), some routine activities such as maintenance and custodial activities could exceed the time-weighted average limit
  • Occasional events such as removal, renovation and vandalism (contact-mode categories) exceeded the OSHA ceiling limit of 10 fibers per cubic centimeter
  • With the more stringent 1975 proposed OSHA limits (0.5 time-weighted average, 5.0 ceiling) and 1977 NIOSH revised recommended limits (0.1 time-weighted average, 0.5 ceiling), the range of activities that could be considered hazardous became more inclusive
  • Under the 1977 NIOSH limits, the only activities remaining outside the limits were quiet conditions and some nonspecific routines
  • The higher contamination levels were associated with disturbance of friable asbestos-containing materials, but bonded material also released fibers under special conditions
• The authors' conclusion: The author concluded that, when occupational standards in force, proposed or recommended were applied, levels found in some indoor situations exceeded those considered potentially carcinogenic, and that exposures were occurring in existing structures among a large and varied population
• Limitations the authors state:
  • The phase-contrast counting method is not specific for asbestos and excludes fibrous particles shorter than 5 micrometers
  • No standard applies to the general indoor environment; the standards used were written for occupational populations
  • The general population differs from workers: it covers all ages, varies in behavior and activity, and may be exposed continuously over long periods
  • Electron microscopy data were not presented, because there was no accepted standard method and agreement among laboratories was poor
  • The hazard estimate relies on significant assumptions and approximations

Topics

Medical terms in this study, explained in our Lexicon: Friable, Carcinogenic.

Related studies

• Indoor airborne asbestos pollution: from the ceiling and the floor — P. Sebastien, J. Bignon, et al. (1982)
• Patterns of histopathological change determined by the point counting method and its application for the hazard assessment of respirable dust — A. Ogami, Y. Morimoto, et al. (2004)
• Occupational exposure to asbestos fibers resulting from use of asbestos gloves — B.S. Samimi, A.M. Williams (1981)
• A comparison of fibre counting stopping rules in the application of the membrane filter method — N.P. Crawford, W.M. Maclaren, et al. (1987)
• Assessment of the epidemiological data relating lung cancer to air pollution — F.E. Speizer (1983)
• Indoor air quality differences between urban and rural preschools in Korea — C. Yoon, K. Lee, et al. (2011)

Browse more research in Annals of the New York Academy of Sciences, or return to medical research.