Environmental and occupational exposure to erionite and related health risks: progress and prospects

Our plain-English summary of Environmental and occupational exposure to erionite and related health risks: progress and prospects, by G. Chen, A. Mannetje, J.A. Salmond, et al (Annals of Work Exposures and Health, 2025).

The study

• Authors: G. Chen, A. Mannetje, J.A. Salmond, J. Douwes
• Journal: Annals of Work Exposures and Health
• Published: 2025;69(7):677-692
• Type of article: Review
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objectives: Erionite, a naturally occurring fibrous zeolite classified as a human carcinogen, is believed to be more potent than asbestos in causing mesothelioma. However, unlike asbestos, erionite has rarely been used for commercial purposes and, as a result, knowledge about exposure pathways is limited. This paper provides a narrative review of the current knowledge regarding the associations between erionite exposure, health effects and exposure circumstances.

Methods: Medline/PubMed and Scopus were systematically searched up to the end of 2024 using keywords related to erionite exposure and health outcomes.

Results: We identified 26 peer-reviewed journal articles reporting on the health effects of erionite exposure, specifically mesothelioma and lung cancer, with mesothelioma being the most extensively studied outcome. Of these, 12 studies focussed on erionite-exposed populations in Turkey, 8 examined health effects among Turkish migrants in northern Europe, and 6 investigated erionite-related health risks in North America (3 in the United States and 3 in Mexico). These studies showed a very high incidence of mesothelioma, often in relatively young individuals, from the Cappadocia region of Turkey, with well-documented environmental exposures to erionite, contributing to a high proportion of all deaths (21% to 51%) in affected villages. Evidence of lung cancer associated with erionite exposure was also found. There is also evidence of erionite exposure-associated mesothelioma in Guanajuato, central Mexico. In the United States, erionite exposure-associated health effects (not mesothelioma) have been reported among people occupationally exposed to erionite. Studies on environmental exposures have shown outdoor concentrations ranging from 0.001 f/ml to 0.3 f/ml, while indoor concentrations have ranged from 0.005 to 1.38 f/ml. Occupational exposure to erionite has been less studied, with only one study in forestry workers showing elevated exposures to erionite ranging from non-detectable to 0.36 f/cc. Erionite deposits have also been identified in other countries such as Italy and New Zealand, but exposures and associated health effects have not yet been studied in these regions.

Conclusion: There is clear evidence that environmental exposure to erionite in the Cappadocia region of Turkey, and Guanajuato in central Mexico are causally associated with the high mesothelioma rates observed in these areas. Evidence for other parts of the world where there is naturally occurring erionite is limited. This review has highlighted significant knowledge gaps, and advocates for further research on occupational exposure to erionite fibres and associated health effects.

© The Author(s) 2025. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

In plain English

This article was a narrative review of published research on erionite, a naturally occurring fibrous zeolite mineral, and its health effects. The authors searched Medline/PubMed and Scopus through the end of 2024 and found 26 journal articles on health effects of erionite exposure: 12 on populations in Turkey, 8 on Turkish migrants in northern Europe, and 6 in North America (3 in the United States, 3 in Mexico). Mesothelioma was the most studied outcome. One reviewed mortality study from Cappadocia, Turkey reported that mesothelioma accounted for 51.5% of deaths in Karain, 38.2% in Tuzköy and 21.8% in Sarihidir between 1970 and 1994. Reviewed Turkish studies measured erionite at 0.001 to 0.3 fibres per millilitre outdoors and 0.005 to 1.38 indoors. Only one study, of US forestry workers, showed elevated work exposures, from non-detectable to 0.36 fibres per cubic centimetre. The authors concluded there is clear evidence that environmental erionite exposure in Cappadocia and in Guanajuato, central Mexico, is causally associated with the high mesothelioma rates there, and that evidence elsewhere is limited.

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: Narrative review based on a systematic literature search of two databases (Medline/PubMed and Scopus) through the end of 2024
• Who was studied: 26 peer-reviewed journal articles on health effects of erionite exposure. Of these, 12 studied erionite-exposed populations in Turkey, 8 studied Turkish migrants in northern Europe, and 6 were from North America (3 United States, 3 Mexico). The review also covered studies reporting airborne erionite levels.
• Exposure: Erionite, a fibrous zeolite. The exposures covered were environmental exposure from building materials (stone, caves, walls made of tuff) in Turkish villages, erionite-containing road gravel in North Dakota, USA, and occupational exposure among outdoor and forestry workers in the United States.
• Main results:
  • In a reviewed 1996 mortality study from Cappadocia, Turkey, mesothelioma accounted for 51.5% of deaths in Karain, 38.2% in Tuzköy and 21.8% in Sarihidir between 1970 and 1994.
  • In a reviewed cohort of 322 inhabitants of Karain, Turkey, followed from 1990 to 2006, annual mesothelioma incidence was 639/100,000 in males and 1266/100,000 in females.
  • In a reviewed Swedish cohort of 162 Turkish immigrants from Karain (1965 to 1997), the standardised incidence ratio for mesothelioma compared with native Swedes of the same sex and age was 135 times higher for men and 1336 times higher for women.
  • In another reviewed Swedish study (Mousavi et al. 2010), Turkish immigrants had a mesothelioma risk of 5.29 (95% CI 3.08 to 8.47) compared with native Swedes.
  • In a reviewed study of Tierra Blanca de Abajo, Guanajuato, Mexico, annual age-standardised mortality rates per 1000 inhabitants aged over 20 were 2.48 (mesothelioma) and 7.09 (lung cancer) for males, and 1.05 (mesothelioma) and 4.75 (lung cancer) for females.
  • Reviewed studies from Turkey found outdoor erionite exposure ranging from 0.001 to 0.3 f/ml.
  • Reviewed studies from Turkey found indoor erionite levels ranging from 0.005 to 1.38 f/ml.
  • In the one reviewed study of forestry workers in Wyoming, South Dakota and Montana (Beaucham et al. 2018), full-shift personal air samples from dust-generating tasks ranged from non-detectable to 0.36 f/cc. The highest level, 0.36 f/cc, was measured in workers operating the masticator. The authors stated this is the only study to show elevated airborne erionite levels at work.
  • Of the 50 samples in that forestry worker study, the authors reported that more than 4 exceeded the 0.1 f/cc asbestos exposure limit.
  • Of the same 50 samples, more than 28 exceeded the new European Commission asbestos limit of 0.01 f/cc.
  • In an earlier US evaluation of workers maintaining dirt roads (2012 to 2013), no erionite was detected in air or bulk samples. The authors noted that the sample number was small (n = 14).
  • The reviewed studies have not documented mesothelioma clusters in naturally occurring erionite areas of the United States.
• The authors' conclusion: The authors concluded that there is clear evidence that environmental erionite exposure in the Cappadocia region of Turkey and in Guanajuato, central Mexico, is causally associated with the high mesothelioma rates in those areas. They concluded that evidence for other parts of the world with naturally occurring erionite is limited.
• Limitations the authors state:
  • There are no standardised sampling and analytical methods for measuring airborne erionite fibres.
  • Erionite-related mesothelioma cases in Turkey may be underreported.
  • Few studies have assessed occupational exposure: only three, all from the United States, and only two of them gave quantitative data.
  • The cross-sectional design and small number of US studies may help explain why no erionite-associated mesothelioma cases have been observed in the United States.

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: Occupational Exposure, erionite, Zeolite, Mesothelioma, Lung Cancer, Cappadocia, Environmental Exposure.

Related studies

• The role of environmental and occupational exposures in Turkish immigrants with fibre-related disease — P. Dumortier, A. Göcmen, et al. (2001)
• Lung diseases due to environmental exposures to erionite and asbestos in Turkey — S. Emri, A. Demir, et al. (2002)
• Erionite in road gravel associated with interstitial and pleural changes--an occupational hazard in western United States — P.H. Ryan, M. Dihle, et al. (2011)
• Geological occurrence, mineralogical characterization, and risk assessment of potentially carcinogenic erionite in Italy — M. Giordani, M. Mattioli, et al. (2017)
• Erionite exposure in North Dakota and Turkish villages with mesothelioma — M. Carbone, Y.I. Baris, et al. (2011)
• High incidence of lung cancer and malignant mesothelioma linked to erionite fibre exposure in a rural community in Central Mexico — M.A. Ortega-Guerrero, G. Carrasco-Núñez, et al. (2015)

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