Skip to main content
PMC home page
Environmental Health Perspectives logoLink to Environmental Health Perspectives
. 1997 Sep;105(Suppl 5):1329–1336. doi: 10.1289/ehp.97105s51329

Approaches to characterizing human health risks of exposure to fibers.

V T Vu 1, D Y Lai 1
PMCID: PMC1470177  PMID: 9400747

Abstract

Naturally occurring and man-made (synthetic) fibers of respirable sizes are substances that have been identified by the U.S. Environmental Protection Agency (U.S. EPA) as priority substances for risk reduction and pollution prevention under the Toxic Substances Control Act (TSCA). The health concern for respirable fibers is based on the link of occupational asbestos exposure and environmental erionite fiber exposure to the development of chronic respiratory diseases, including interstitial lung fibrosis, lung cancer, and mesothelioma in humans. There is also considerable laboratory evidence indicating that a variety of fibers of varying physical and chemical characteristics can elicit fibrogenic and carcinogenic effects in animals under certain exposure conditions. This paper discusses key scientific issues and major default assumptions and uncertainties pertaining to the risk assessment of inhaled fibers. This is followed by a description of the types of assessment performed by the U.S. EPA to support risk management actions of new fibers and existing fibers under TSCA. The scope and depth of these risk assessments, however, vary greatly depending on whether the substance under review is an existing or a new fiber, the purpose of the assessment, the availability of data, time, and resources, and the intended nature of regulatory action. In general, these risk assessments are of considerable uncertainty because health hazard and human exposure information is often incomplete for most fibers. Furthermore, how fibers cause diseases and what specific determinants are critical to fiber-induced toxicity and carcinogenicity are still not completely understood. Further research to improve our knowledge base in fiber toxicology and additional toxicity and exposure data gathering are needed to more accurately characterize the health risks of inhaled fibers.

Full text

PDF
1329

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Barnes D. G., Dourson M. Reference dose (RfD): description and use in health risk assessments. Regul Toxicol Pharmacol. 1988 Dec;8(4):471–486. doi: 10.1016/0273-2300(88)90047-5. [DOI] [PubMed] [Google Scholar]
  2. Barrett J. C. Cellular and molecular mechanisms of asbestos carcinogenicity: implications for biopersistence. Environ Health Perspect. 1994 Oct;102 (Suppl 5):19–23. doi: 10.1289/ehp.94102s519. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Davis J. M., Jones A. D. Comparisons of the pathogenicity of long and short fibres of chrysotile asbestos in rats. Br J Exp Pathol. 1988 Oct;69(5):717–737. [PMC free article] [PubMed] [Google Scholar]
  4. Grond J., van Goor H., Erkelens D. W., Elema J. D. Glomerular sclerosis in Wistar rats: analysis of its variable occurrence after unilateral nephrectomy. Br J Exp Pathol. 1986 Aug;67(4):473–479. [PMC free article] [PubMed] [Google Scholar]
  5. McClellan R. O., Miller F. J., Hesterberg T. W., Warheit D. B., Bunn W. B., Kane A. B., Lippmann M., Mast R. W., McConnell E. E., Reinhardt C. F. Approaches to evaluating the toxicity and carcinogenicity of man-made fibers: summary of a workshop held November 11-13, 1991, Durham, North Carolina. Regul Toxicol Pharmacol. 1992 Dec;16(3):321–364. doi: 10.1016/0273-2300(92)90011-w. [DOI] [PubMed] [Google Scholar]
  6. Monchaux G., Bignon J., Jaurand M. C., Lafuma J., Sebastien P., Masse R., Hirsch A., Goni J. Mesotheliomas in rats following inoculation with acid-leached chrysotile asbestos and other mineral fibres. Carcinogenesis. 1981;2(3):229–236. doi: 10.1093/carcin/2.3.229. [DOI] [PubMed] [Google Scholar]
  7. Pott F., Roller M., Kamino K., Bellmann B. Significance of durability of mineral fibers for their toxicity and carcinogenic potency in the abdominal cavity of rats in comparison with the low sensitivity of inhalation studies. Environ Health Perspect. 1994 Oct;102 (Suppl 5):145–150. doi: 10.1289/ehp.94102s5145. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Schlesinger R. B. Comparative deposition of inhaled aerosols in experimental animals and humans: a review. J Toxicol Environ Health. 1985;15(2):197–214. doi: 10.1080/15287398509530647. [DOI] [PubMed] [Google Scholar]
  9. Stanton M. F., Layard M., Tegeris A., Miller E., May M., Morgan E., Smith A. Relation of particle dimension to carcinogenicity in amphibole asbestoses and other fibrous minerals. J Natl Cancer Inst. 1981 Nov;67(5):965–975. [PubMed] [Google Scholar]
  10. Warheit D. B. Interspecies comparisons of lung responses to inhaled particles and gases. Crit Rev Toxicol. 1989;20(1):1–29. doi: 10.3109/10408448909037474. [DOI] [PubMed] [Google Scholar]
  11. Yu C. P., Zhang L., Oberdörster G., Mast R. W., Glass L. R., Utell M. J. Clearance of refractory ceramic fibers (RCF) from the rat lung: development of a model. Environ Res. 1994 May;65(2):243–253. doi: 10.1006/enrs.1994.1035. [DOI] [PubMed] [Google Scholar]

Articles from Environmental Health Perspectives are provided here courtesy of National Institute of Environmental Health Sciences

RESOURCES