Re-evaluation and re-classification of erionite series minerals

Our plain-English summary of Re-evaluation and re-classification of erionite series minerals, by A.U. Dogan, M. Dogan (Environmental Geochemistry and Health, 2008).

The study

• Authors: A.U. Dogan, M. Dogan
• Journal: Environmental Geochemistry and Health
• Published: 2008;30(4):355-66
• Cited by: 20 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Governments and industries have introduced regulatory measures requiring safety controls to limit asbestos exposure of the general public and asbestos workers. Although erionite is a more potent health hazard mineral than asbestos, it has received far less attention. Precise definition of erionite, types of these fibrous minerals, and most importantly, characterization requirements still raise questions and often lead to arguments and even legal disputes. Many bulk erionite samples used in animal and cell experiments for carcinogenicity are not mineralogically pure. To test this hypothesis, we characterized two erionite standards from Rome, Oregon, and Pine Valley, Nevada, USA. These standards were characterized quantitatively using modern analytical techniques, and one of them, the erionite standard from Rome, Oregon, passed the required tests for positive identification, but the other, the erionite standard from Pine Valley, Nevada, did not. Furthermore, we observed ambiguous definitions, incorrect identifications, and inaccurate reporting of clinical investigations. To address this problem, we established characterization guidelines for positive identification of erionite using a modified balance error formula, and we re-evaluated and re-classified published erionite data from the literature as erionite-Ca, erionite-Na, and erionite-K. If data did not pass either the E% or Mg-content test, then we propose that reference to them in the literature be disregarded. Erionite requires special attention from the mineralogical community to help establish its true carcinogenetic properties. We believe that the characterization guidelines established in this paper will contribute to setting up rules and regulations for evaluation of erionite by regulatory agencies.

In plain English

This was a mineralogy study, not a study of people or disease. The authors analysed two erionite reference samples (erionite is a fibrous zeolite mineral), from Rome, Oregon and Pine Valley, Nevada, using microscopy, X-ray diffraction and chemical analysis. They applied two tests: a chemical 'balance error' within plus or minus 10%, and magnesium below 0.80 atoms per cell. The Rome sample passed both tests and was classed as erionite-K. The Pine Valley sample failed, with balance errors of -55.82 and -56.15 in two analyses. The authors also recalculated published erionite analyses from many countries, sorting those that passed into erionite-Ca, erionite-Na and erionite-K. They reported that none of the published erionite results from Turkey's Cappadocia region before 2006 passed both tests. The authors concluded that data failing the tests should be disregarded, and that animal and cell experiments should use only erionite that has passed them. They noted that passing the tests does not rule out similar zeolites such as clinoptilolite.

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: Laboratory mineralogical characterization of two erionite reference samples, plus recalculation and re-classification of published erionite chemical analyses from the literature
• Who was studied: Two erionite standard samples: Rome, Oregon (CBES-6120) and Pine Valley, Nevada, USA (CBES-6119). The study also covered published erionite analyses from locations worldwide. No people were studied, and no study dates are given.
• Exposure: Not a human exposure study. The material examined was erionite, a fibrous zeolite mineral, classified into erionite-Ca, erionite-Na and erionite-K. Classification used a balance error test (within plus or minus 10%) and a magnesium test (less than 0.80 atoms per cell).
• Main results:
  • The Rome, Oregon standard passed both the balance error and magnesium tests (balance error -0.25) and was classified as erionite-K.
  • The Pine Valley, Nevada standard did not pass the tests. Its two analyses gave balance errors of -55.82 and -56.15 and magnesium values of 1.41 and 1.70.
  • Some published erionite data did not pass the balance error test, the magnesium test, or both. The authors said these could not be accepted as erionite.
  • None of the published erionite results from the Cappadocia region of Turkey before 2006 passed the two tests.
  • In the authors' recalculation, samples from their own earlier study (Dogan et al. 2006) passed. Those from the villages of Karain, 'Old' Sarihidir and Karlik were erionite-K; those from Tuzkoy were erionite-Na.
  • Data from Durkee, Oregon by three different authors were recalculated as erionite-Ca, erionite-Na and erionite-K respectively. These samples were classed as 'undifferentiated' erionite pending clarification.
• The authors' conclusion: The authors concluded that published erionite data failing either test should be disregarded. They also concluded that animal and cell experiments should be performed only with minerals that have passed the quantitative characterization tests.
• Limitations the authors state:
  • The authors stated that a result within the balance error limits does not confirm erionite. The mineral may instead be another zeolite with similar composition and structure, such as clinoptilolite.

Topics

Medical terms in this study, explained in our Lexicon: erionite, Asbestos Exposure.

Related studies

• Erionite series minerals: mineralogical and carcinogenic properties — A.U. Dogan, M. Dogan, et al. (2008)
• Quantitative characterization of the mesothelioma-inducing erionite series minerals by transmission electron microscopy and energy dispersive spectroscopy — M. Dogan (2012)
• New insights into the toxicity of mineral fibres: A combined in situ synchrotron μ-XRD and HR-TEM study of chrysotile, crocidolite, and erionite fibres found in the tissues of Sprague-Dawley rats — A.F. Gualtieri, N. Bursi Gandolfi, et al. (2017)
• Erionite exposure in North Dakota and Turkish villages with mesothelioma — M. Carbone, Y.I. Baris, et al. (2011)
• Lung diseases due to environmental exposures to erionite and asbestos in Turkey — S. Emri, A. Demir, et al. (2002)
• Erionite and asbestos differently cause transformation of human mesothelial cells — P. Bertino, A. Marconi, et al. (2007)

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