Pulmonary mineral fibers after occupational and environmental exposure to asbestos in the Russian chrysotile industry

Our plain-English summary of Pulmonary mineral fibers after occupational and environmental exposure to asbestos in the Russian chrysotile industry, by A. Tossavainen, E. Kovalevsky, E. Vanhala, et al (American Journal of Industrial Medicine, 2000).

The study

• Authors: A. Tossavainen, E. Kovalevsky, E. Vanhala, T. Tuomi
• Journal: American Journal of Industrial Medicine
• Published: 2000;37(4):327-33
• Cited by: 18 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: As an indicator of occupational, domestic, and environmental exposure, the level and type of asbestos fibers were determined from lung tissue samples of workers and residents who resided in the area of the world's largest asbestos mine at Asbest, Russia.

Methods: Electron microscopy was used to analyze and measure the concentration of asbestos fibers in a series of 47 autopsies at the Asbest Town Hospital. Work histories were obtained from pathology reports and employment records.

Results: In 24 chrysotile miners, millers, and product manufacturers, the pulmonary concentrations of retained fibers (over 1 microm in length) were 0. 8-50.6 million f/g for chrysotile, and < 0.1-1.9 million f/g for amphiboles (tremolite and anthophyllite). The concentrations were lower in 23 persons without any known occupational contact with asbestos; 0.1-14.6 million f/g for chrysotile, and < 0.1-0.7 million f/g for amphiboles. On average, 90% of all inorganic fibers were chrysotile, and 5% tremolite/anthophyllite. No amosite or crocidolite fibers were detected in any of the samples.

Conclusions: The mean and range of pulmonary chrysotile concentrations were about the same as reported previously from the Canadian mining and milling industry. In the Russian samples, the mean concentration of tremolite fibers were less by at least one order of magnitude. Occupational contact was the most important source of asbestos exposure.

Copyright 2000 Wiley-Liss, Inc.

In plain English

This study measured asbestos fibers in lung tissue from 47 long-term residents of Asbest, Russia. Samples were collected in 1996 to 1997 at the Asbest Town Hospital, unselected by cause of death, occupation or asbestos exposure. Of 24 people from the chrysotile industry, 19 had confirming employment records and 5 had most likely worked there without records to confirm it. Counting fibers longer than 1 micrometer by electron microscopy, the authors found chrysotile levels of 0.8 to 50.6 million fibers per gram of dry tissue (mean 10.7 million) in this group. In 23 people with no known occupational exposure, the range was 0.1 to 14.6 million (mean 2.6 million). Tremolite and anthophyllite made up about 5% of fibers. No amosite or crocidolite was found. The authors concluded that occupational contact was the most important exposure source. Chrysotile levels were about the same as reported from Canadian mining and milling, with tremolite lower by at least one order of magnitude. For the highest levels in residents without known occupational exposure, the authors pointed to unknown, forgotten or hidden occupational or domestic exposures as most probable. No histopathology or chest x-ray data were available.

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: Descriptive study of mineral fiber content in lung tissue from an unselected hospital autopsy series, analyzed by scanning electron microscopy with x-ray microanalysis
• Who was studied: 47 long-term residents of Asbest Town, Russia (35 males, 12 females), with lung samples collected 1996 to 1997 at the Asbest Town Hospital (46 autopsies, one thorax surgery). Adults were aged 21 to 83, plus two children aged 1 month and 13 years. Three additional archival samples (one asbestosis patient, two residents) were also analyzed.
• Exposure: Work in the chrysotile industry (mining, milling and product manufacture at Uralasbest Company and the ATI Plant). 19 persons were confirmed by employment records, 5 had probably worked there but this was unconfirmed, and 23 had no known occupational exposure. Fibers measured were chrysotile and the amphiboles tremolite and anthophyllite (reported as MgCaFe-silicates).
• Main results:
  • In the 24 persons who had worked in the asbestos industry (19 confirmed, 5 probable), lung concentrations were 0.8 to 50.6 million fibers per gram dry tissue for chrysotile and less than 0.1 to 1.9 million f/g for MgCaFe-silicates (tremolite/anthophyllite).
  • In the 23 persons without known occupational exposure, concentrations were 0.1 to 14.6 million f/g for chrysotile and less than 0.1 to 0.7 million f/g for MgCaFe-silicates.
  • Mean chrysotile concentration was 10.7 million f/g in the asbestos workers versus 2.6 million f/g in those without known occupational exposure.
  • Amphiboles made up about 5% of all mineral fibers on average, ranging from 2% in chrysotile millers and product users to 9% in miners.
  • No amosite or crocidolite was detected in any sample.
  • Fiber concentrations had no obvious relation to age, gender, or cause of death.
  • Four quarry workers with 16 to 46 years of work had relatively low chrysotile levels (0.9 to 6.4 million f/g).
  • The highest single concentration was in an archival sample from an asbestosis patient: 163 million f/g chrysotile.
• The authors' conclusion: The authors concluded that occupational contact was the most important source of asbestos exposure. They found pulmonary chrysotile levels about the same as reported from the Canadian mining and milling industry, with mean tremolite levels lower by at least one order of magnitude. For the highest levels among residents without known occupational exposure, they considered the most probable causes to be unknown, forgotten, or hidden exposures related to occupational or domestic use of asbestos products, such as building materials.
• Limitations the authors state:
  • No histopathology or chest x-ray data were available for any case.
  • The scanning electron microscopy method may undercount thin chrysotile fibers compared with transmission electron microscopy.
  • For 5 persons, asbestos industry work was considered likely but could not be confirmed by employment records.

Mines named here

Asbestos mines this study is about. Each mine's page says who ran it, when it worked, and what it produced.

• Bajenova district, Bajenova district, about 90 km northeast of Sverdlovsk, Russia

All asbestos mines

Topics

The National Library of Medicine indexes this study under subjects our site covers: Amosite, Anthophyllite, Chrysotile, Crocidolite, Tremolite.

Medical terms in this study, explained in our Lexicon: Mineral Fiber, Environmental Exposure, Chrysotile, Pathology Report, Amphibole Group, Tremolite, Anthophyllite, Amosite.

Related studies

• Lung mineral fibers of former miners and millers from Thetford-Mines and asbestos regions: a comparative study of fiber concentration and dimension — A. Nayebzadeh, A. Dufresne, et al. (2001)
• Role of associated mineral fibres in chrysotile asbestos health effects: the case of balangeroite — F. Turci, M. Tomatis, et al. (2009)
• A review of the cohorts with environmental and occupational mineral fiber exposure — S. Metintas, G. Ak, et al. (2019)
• Occupational cohort study of current and former workers exposed to chrysotile in mine and processing facilities in Asbest, the Russian Federation: Cohort profile of the Asbest Chrysotile Cohort study — J. Schüz, I. Bukhtiyarov, et al. (2020)
• Fiber size and number in workers exposed to processed chrysotile asbestos, chrysotile miners, and the general population — A. Churg, B. Wiggs (1986)
• Deposition and clearance of chrysotile asbestos — A. Churg (1994)

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