Comparative studies on the cytotoxicity of amphibole and serpentine asbestos.

Abstract

The chemical and physical properties of serpentine and amphibole asbestos are considered in the context of teir interaction with tissue of the tracheobronchial tree and lungs. In vitro studies in cultures of several types are evaluated and work with the erythrocyte hemolysis system is reviewed. Although fibers ofthe two major mineral types differ substantialy, it is likely they are modified by secretions and membranes of cells after inhalation to the respiratory tract. Investigations using virgin asbestos might not provide an accurate picture of events in vitro.Asbestos is not one, but a family of, hydrated silicate minerals having a fibrous crystalline structure. The types of asbestos differ mineralogically and, as might be expected, these chemical and physical differences are reflected in the mechanism of interaction of fibers with cells. In this paper, we consider comparatively the characteristics of serpentine and amphibole asbestos and attempt to relate these features to the pathogenetic effects on tissues of the respiratory tract. Structural and Chemical PropertiesSerpentine asbestos derives its name from the pliable, curled, "serpentlike" property of the fiber (Fig. 1). Chrysotile, the only commercially important mineral of this type, comprises over 90% of the asbestos mined in the world today. The members of the amphibole asbestos group are more numerous, but have fewer commercial uses. The amphiboles (crocidolite, amosite, and anthophyllite) exhibit a coarse, fibrous structure (Fig. 2).The mineralogy of asbestos is complex and incompletely defined. The types vary in major ele-

Amphibole, but not chrysotile, asbestos induces anti-nuclear autoantibodies and IL-17 in C57BL/6 mice

“…Although the definition of asbestos includes both families, amphiboles and serpentine (chrysotile), fibers in these groups are clearly different morphologically, and have unique physicochemical properties (Craighead et al, 1980). As a broad group of silicate fibers, asbestos agents, following their inhalation, have been shown to give rise to lung carcinoma, interstitial fibrosis (asbestosis), pleural scarring, and mesothelioma.…”

In vitro approaches for determining mechanisms of toxicity and carcinogenicity by asbestos in the gastrointestinal and respiratory tracts.

“…Because asbestos is a family of fibrous hydrated silicates, each with unique chemicophysical features, the relative toxicity of various types of asbestos has been assessed comparatively in cell and organ cultures derived from intestinal, liver, colonic (4), and tracheobronchial epithelium (2,3,10,11). Cell damage, compared to untreated controls, is assessed by inhibition of growth or colony formation (2,4), release of 5'Cr (10) or 75Se (11) from prelabeled cultures, and quantitation of lysosomal or cytoplasmic enzymes in medium (12).…”

“…To elucidate possible mechanisms of fiber-induced disease, the interaction of asbestos with epithelial cells ofthe gastrointestinal and respiratory tracts has been studied in organ and cell cultures. After introduction of asbestos, the uptake of fibers by mucosal cells is observed concomitantly with damage, death, and regeneration of the epithelium (1)(2)(3). The extent of these changes, which might be related to the process of carcinogenesis, varies with the type (2)(3)(4), charge (5,6), crystallization (7), and size (8,9) of the fibers.…”

“…After introduction of asbestos, the uptake of fibers by mucosal cells is observed concomitantly with damage, death, and regeneration of the epithelium (1)(2)(3). The extent of these changes, which might be related to the process of carcinogenesis, varies with the type (2)(3)(4), charge (5,6), crystallization (7), and size (8,9) of the fibers. Discussed here are experiments in vitro that define asbestosinduced cellular responses and their possible relationship to neoplasia in gastrointestinal and respiratory epithelium.…”

In-vitro toxicology of respirable iron-rich particles relevant to mining industry: a high throughput framework for interpreting environmental particulate matter toxicity

“…While the exact mechanism of toxicity is debated, inhalation of amphibole asbestos and very high concentrations of serpentine asbestos is associated with diffuse interstitial pulmonary fibrosis, the formation of asbestos bodies, pleural inflammation, lung cancer and mesotheliomas [126][127][128][129] . Symptoms may take up to 40 years to develop after the initial exposure, although in up to a fifth of patients abnormalities such as diffuse interstitial pulmonary fibrosis may not appear on X-ray 129,130 .…”