Iron, asbestos, and carcinogenicity

Our plain-English summary of Iron, asbestos, and carcinogenicity, by E.D. Weinberg (Lancet, 1989).

The study

• Author: E.D. Weinberg
• Journal: Lancet
• Published: 1989;1(8651):1399-400
• Type of article: Letter
• Cited by: 27 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. 000176).

Summary of the article

In this letter, the author argued that the iron content of asbestos may help explain why some asbestos types are more carcinogenic than others. He noted that iron overload increases the risk of neoplasia, that iron is an essential nutrient for cancer cells and impairs inflammatory defence mechanisms, and that overload can arise from the diet, enhanced iron absorption, parenteral iron or blood, cigarette smoke, or occupational sources such as iron ore mining and milling, welding, and painting with iron-containing substances. Citing published work, he stated that the amphibole varieties crocidolite and amosite are strongly carcinogenic, while the serpentine type chrysotile is far less dangerous, and that carcinogenicity has been correlated in part with the physical characteristics of the fibres. He proposed that chemical composition also plays a part: crocidolite and amosite contain approximately 27% and 31% iron, compared with about 0.3% for chrysotile. Asbestos that contains or is contaminated with iron catalyses the generation of hydroxyl radicals, which increase DNA strand breakage and lipid membrane peroxidation; these activities are prevented by the chelator desferrioxamine. Noting that over 95% of asbestos mined worldwide is chrysotile, he suggested that eliminating industrial use of crocidolite, amosite, and chrysotile contaminated with iron or iron-containing tremolite could strikingly reduce asbestos-related cancer. He added that even then, dust control and discouraging cigarette smoking by asbestos workers and their families would remain prudent.

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 is a letter to the editor of The Lancet, not a research study. It reported no new data and relied on earlier publications. The author began from the view that iron overload increases cancer risk, and noted that overload can come from diet, cigarette smoke, or jobs such as welding and iron ore mining and milling. Citing earlier work, the letter stated that the amphibole types crocidolite and amosite are strongly carcinogenic, while the serpentine type chrysotile is far less dangerous. The author proposed that iron content plays a part alongside the physical characteristics of the fibres. The letter gave approximate iron contents of 27% for crocidolite, 31% for amosite and 0.3% for chrysotile. It cited laboratory reports that iron-containing asbestos generates hydroxyl radicals that damage DNA and lipid membranes. The author suggested that ending industrial use of crocidolite, amosite, and chrysotile contaminated with iron or iron-containing tremolite could lead to a striking reduction in asbestos-related cancer. The author added that dust control and discouraging smoking would still be prudent.

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: letter to the editor (correspondence) putting forward a hypothesis based on previously published work; no original data
• Exposure: Inhaled asbestos: the amphiboles crocidolite and amosite (iron-containing silicates), chrysotile (a magnesium silicate), and chrysotile contaminated with iron or iron-containing tremolite. Also iron overload from diet, cigarette smoke and occupations such as iron ore mining and milling, welding, and painting with iron-containing substances.
• Main results:
  • Citing earlier publications, the letter stated that inhaled asbestos may increase the risk of cancer of the lungs or of membranes (mesothelioma), that the amphiboles crocidolite and amosite are strongly carcinogenic, and that chrysotile is far less dangerous.
  • Citing an earlier publication, the letter gave approximate iron contents of 27% (crocidolite), 31% (amosite) and 0.3% (chrysotile). The scan prints the last figure as '0-3%'.
  • Citing laboratory studies by others, the letter stated that asbestos containing or contaminated with iron catalyses hydroxyl radical generation, which increases DNA strand breakage and lipid membrane peroxidation. It added that these activities are prevented by the chelator desferrioxamine.
  • Citing an earlier publication, the letter stated that over 95% of asbestos mined worldwide is chrysotile.
• The authors' conclusion: The author suggested that eliminating industrial use of crocidolite, amosite, and any chrysotile contaminated with iron or iron-containing tremolite could lead to a striking reduction in asbestos-related cancer morbidity. The author also wrote that, even then, dust control and discouraging smoking among asbestos workers and their families would be prudent.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Carcinogenic, Amphibole Group, Crocidolite, Amosite, Serpentine Group, Chrysotile, Hydroxyl Radical, Tremolite.

Related studies

• Role of iron in carcinogenesis: cancer as a ferrotoxic disease — S. Toyokuni (2009)
• Free radical generation at the solid/liquid interface in iron containing minerals — B. Fubini, L. Mollo, et al. (1995)
• Iron and reactive oxygen species in the asbestos-induced tumor necrosis factor-alpha response from alveolar macrophages — P.P. Simeonova, M.I. Luster (1995)
• Iron mobilization from crocidolite asbestos greatly enhances crocidolite-dependent formation of DNA single-strand breaks in phi X174 RFI DNA — L.G. Lund, A.E. Aust (1992)
• Participation of nitric oxide and iron in the oxidation of DNA in asbestos-treated human lung epithelial cells — C.C. Chao, S.H. Park, et al. (1996)
• Role of iron in the reactivity of mineral fibers — B. Fubini, L. Mollo (1995)

Browse more research in Lancet, or return to medical research.