Flame-attenuated fiberglass: another asbestos?

Our plain-English summary of Flame-attenuated fiberglass: another asbestos?, by K.H. Kilburn (American Journal of Industrial Medicine, 1982).

The study

• Author: K.H. Kilburn
• Journal: American Journal of Industrial Medicine
• Published: 1982;3(1):121-5
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This 1982 article is a commentary, not a new study. The author reviewed fiberglass manufacture and published studies, asking whether flame-attenuated fiberglass, a finer fiber made from about 1960, might act like asbestos. The author cited a 1977 rat experiment by Stanton and co-workers in which fine fiberglass placed in the pleural space produced pleural sarcomas resembling those produced in the same model by chrysotile, crocidolite or amosite. The author argued that mortality studies of fiberglass workers were not reassuring: they covered only 500 deaths (7.2%) among 6,952 men, and who was exposed to flame-attenuated fiber was unknown. The author also wrote that the data so far suggested only a low level of adverse effects for bronchiectasis-bronchitis or respiratory cancers. The author reasoned that if flame-attenuated fiberglass, introduced in 1960, took a decade to reach sizable numbers of workers, then adding 20 years pointed to 1980-1990 as the decade when the first tumors or fibrosis due to fiberglass would be diagnosed. The author concluded that exposed workers should be placed under surveillance and proposed five types of studies.

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: commentary reviewing the history of fiberglass manufacture and published animal and human studies; no new data were collected
• Who was studied: No new study population. The author discussed published animal experiments and studies of fiberglass production workers, including mortality studies covering 500 deaths from two cohorts totalling 6,952 men.
• Exposure: Flame-attenuated (thin) fiberglass, introduced about 1960 and down to submicron diameters, compared with the earlier large-diameter fiberglass made from about 1930 to 1960.
• Main results:
  • Reported from Stanton and co-workers (1977), not this article: in rats with fine fiberglass implanted in the pleural space, fibers 8 microns and longer produced pleural sarcomas in 65 to 85% of the animals.
  • Reported from Stanton and co-workers: the rat tumors resembled those produced in the same experimental model by chrysotile, crocidolite or amosite.
  • The author's own reworking of an X-ray survey by Nasr et al (2,028 employees of a fiberglass plant): if only about 100 workers were exposed to flame-attenuated fiber and that number is used as the denominator, as many as 26% showed abnormalities suggesting diffuse alveolar disease.
  • The author judged that the published data so far suggested only a low level of adverse health effects or risks for the bronchiectasis-bronchitis syndrome or for respiratory cancers.
  • The author's conditional forecast, not an observed finding: if flame-attenuated fiberglass was introduced in 1960 and took a decade to reach sizable worker populations, adding 20 years pointed to 1980-1990 as the decade for diagnosis of the first tumors or fibrosis due to fiberglass.
• The authors' conclusion: The author concluded that groups of workers exposed to flame-attenuated fiberglass should be placed under surveillance. The author proposed five types of studies and saw a mortality study of a long-exposed cohort as crucial.
• Limitations the authors state:
  • The author stated that the extent of use of flame-attenuated fiberglass is not known.
  • The author stated that the published literature does not show whether workers exposed to flame-attenuated fiberglass were ever studied separately with sensitive methods.
  • The author stated that case reports of respiratory illness after fiberglass exposure are scattered and difficult to verify.

Related studies

• Difficulties of attribution of effect in workers exposed to fiberglass and asbestos — K.H. Kilburn, R.H. Warshaw (1991)
• Historical cohort study of US man-made vitreous fiber production workers: I. 1992 fiberglass cohort follow-up: initial findings — G.M. Marsh, A.O. Youk, et al. (2001)
• Comparative pulmonary responses to inhaled inorganic fibers with asbestos and fiberglass — K.P. Lee, C.E. Barras, et al. (1981)
• A case-control study of malignant and non-malignant respiratory disease among employees of a fiberglass manufacturing facility. II. Exposure assessment — L. Chiazze, D.K. Watkins, et al. (1993)
• Pulmonary response of mice to fiberglass: cytokinetic and biochemical studies — I.Y. Adamson, H. Prieditis, et al. (1995)
• Pathogenicity of a special-purpose glass microfiber (E glass) relative to another glass microfiber and amosite asbestos — R.T. Cullen, A. Searl, et al. (2000)

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