Role of manmade mineral fibres in the causation of cancer

Our plain-English summary of Role of manmade mineral fibres in the causation of cancer, by P.E. Enterline (British Journal of Industrial Medicine, 1990).

The study

• Author: P.E. Enterline
• Journal: British Journal of Industrial Medicine
• Published: 1990;47(3):145-6
• Cited by: 8 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 000013).

Summary of the article

This editorial considered whether manmade mineral fibres (MMMF) cause cancer. It drew on two large epidemiological studies, one in the United States and one in Europe, of over 40 000 MMMF production and maintenance workers. Twenty years or more after first exposure, rock/slag wool workers had a 30% (United States) and 40% (Europe) increase in respiratory cancer. Glass wool workers had an excess of roughly 10%, and glass filament workers had none. The author argued that the estimated fibre exposures were too low to explain these excesses, even by comparison with asbestos. Animal studies had indicated that, fibre for fibre, MMMF were much less carcinogenic than asbestos. Asbestos had been used in four of six United States rock/slag wool plants and in four European plants, but these plants showed no greater excess than plants that did not use it. Both studies linked the excess to the use of slag. Slag plants had about double the expected respiratory or lung cancer deaths. Plants using slag from copper smelters, believed or known to be contaminated with arsenic, had two and a half (Europe) and three and a half (United States) times the expected deaths. The author concluded that fibres probably did not play the major part in the excess among slag wool workers. He considered a proposed US Environmental Protection Agency classification of rock/slag wool as more hazardous than glass wool probably misleading. He judged that ordinary MMMF carry some small cancer hazard, much less than that of asbestos.

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 editorial discussed US and European studies of over 40 000 production and maintenance workers in manmade mineral fibre (MMMF) plants. Rock/slag wool workers had a 30% (US) and 40% (Europe) increase in respiratory cancer 20 or more years after first exposure; glass wool workers, roughly 10%. The author considered past asbestos use, but plants using it had no greater excess. In Europe, lung cancer deaths 20 years from first exposure were about double those expected during slag use, and two and a half times expected with copper-smelter slag believed contaminated with arsenic. In the US, as of the end of 1982, respiratory cancer deaths 20 years from first exposure were double those expected in four plants always using slag; two plants that used rock early, then slag, had no excess. In one US plant using copper-smelter slag known to contain arsenic, such deaths were three and a half times expected. The author concluded that fibres probably do not play the major part in the slag wool excess, and that ordinary MMMF carry a small cancer hazard, much less than asbestos.

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: Editorial (opinion piece) discussing the findings of two earlier epidemiological studies; no new data were collected
• Who was studied: The studies discussed covered over 40 000 production and maintenance workers in manmade mineral fibre plants, in one United States study and one European study
• Exposure: Manmade mineral fibres: rock wool, slag wool, glass wool and glass filament. Also discussed: asbestos used in some plants, slag feedstock (some contaminated with arsenic), and furnace fumes
• Main results:
  • As reported in the two studies discussed, workers producing rock or slag wool had a 30% increase in respiratory cancer 20 years or more after first exposure in the United States study and a 40% increase in the European study
  • Workers producing glass wool had roughly a 10% excess in both studies. No excess was seen in a small group of glass filament workers
  • Asbestos was fairly certainly used in four of the six US rock/slag wool plants, but the excess of respiratory cancer in those four plants was no greater than in the two plants that did not use asbestos
  • In the European study, the four rock/slag wool plants that used asbestos had no excess of lung cancer deaths compared with plants that did not use asbestos
  • In the European study, lung cancer mortality 20 years from first exposure was about double that expected during slag use. It was two and a half times expected when the slag came from a copper smelter and was believed to be contaminated with arsenic
  • In the US study, as of the end of 1982, the four plants that always used slag had a respiratory cancer death rate 20 years from first exposure double that expected. In the same comparison, the two plants that used rock in the early years and then changed to slag had no excess of respiratory cancer
  • In one US plant that received slag from a copper smelter that was known to be contaminated with arsenic, respiratory cancer deaths 20 years from first exposure were three and a half times expected
  • MMMF production workers were also exposed to other disease-causing substances, including furnace fumes containing polycyclic aromatic hydrocarbons and contaminants in the feed stock
• The authors' conclusion: The author concluded that fibres probably do not play the major part in the excess of cancer among slag wool workers, so fibre potency should not be estimated from these data. The author also concluded that ordinary MMMF made from rock, slag or glass carry some small cancer hazard, much less than that of asbestos. The author also said the US Environmental Protection Agency classification would probably be misread as a ranking of fibre potency
• Limitations the authors state:
  • The author stated that comparing studies of MMMF production workers with studies of asbestos workers is problematic, because MMMF workers had other exposures that the asbestos workers did not
  • The author noted that in the European study it is unclear whether fibre exposure was higher during periods of slag use

Topics

Medical terms in this study, explained in our Lexicon: Causation, Carcinogenic, Lung Cancer.

Related studies

• Carcinogenesis and mineral fibres — J.C. Wagner, G. Berry, et al. (1980)
• Adsorption of benzo(a)pyrene on to asbestos and manmade mineral fibres in an aqueous solution and in a biological model solution — P. Gerde, P. Scholander (1988)
• Lung dust analysis in the assessment of past exposure of man-made mineral fibre workers — J.C. McDonald, B.W. Case, et al. (1990)
• Health aspects of man-made mineral fibres. A review — J.W. Hill (1977)
• Clinical trials of vitamin and mineral supplements for cancer prevention — P. Greenwald, D. Anderson, et al. (2007)
• The epidemiologic evidence for elongate mineral particle (EMP)-related human cancer risk — P. Boffetta, K.A. Mundt, et al. (2018)

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