Persistence of natural mineral fibers in human lungs: an overview
Autor: | Joanne L. Wright, Andrew Churg |
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Jazyk: | angličtina |
Rok vydání: | 1994 |
Předmět: |
Time Factors
Asbestos Serpentine Metabolic Clearance Rate Health Toxicology and Mutagenesis Population Mineralogy Physiology Natural mineral Persistence (computer science) Chrysotile Animals Humans Fiber education Lung Amphibole education.field_of_study Minerals Chemistry Public Health Environmental and Occupational Health Asbestos Environmental Exposure Body Burden Clearance rate Clearance Research Article |
Zdroj: | Environmental Health Perspectives |
ISSN: | 0091-6765 |
Popis: | Virtually all available data on persistence of naturally occurring mineral fibers in human lungs have been derived from studies of asbestos fiber loads. These studies indicate that, although both amphibole and chrysotile asbestos fibers are found in the lungs of the general population and exposed workers, amphibole fibers are universally present in disproportionately large and chrysotile fibers in disproportionately small amounts compared to their known abundance in the original inhaled dusts. Why this should be remains unclear. Most reports have shown that fiber accumulation is proportional to measured exposure for amphiboles, but this is not generally true for chrysotile. Very little information is available on actual fiber clearance rates from human lungs. For amosite and crocidolite, estimated clearance half-times are measured in years to decades, whereas for chrysotile the available, rather indirect, data suggest that the vast majority of fibers are cleared within months, although some fibers may be sequestered and very slowly cleared. Overall these studies suggest that the differences between amphibole and chrysotile fiber burdens in man reflect much faster clearance of chrysotile fibers, rather than a failure of chrysotile deposition. A variety of other naturally occurring fibers are commonly found in human lungs, but there are no data on their rates of accumulation or disappearance. |
Databáze: | OpenAIRE |
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