Crystal faces and cleavage planes in quartz as templates in biological processes

Abstract

Some species of minerals, when comminuted and aerosolized in the form of respirable-size particulate dusts, are recognized as capable of producing disease in man after their inhalation. Comprehensive listings of such agents are in the current literature (e.g. in Aponte, 1970; Langer & Mackler, 1972; Ehrenreich et al. 1973a, b) and many of these and their effects are well known and receive much attention. Asbestos fibres of all varieties, ampbibole and quartz contaminated talcum powders (see Rohl et al. 1976), fibrous amphiboles and their cleavage fragments which contaminate the ambient environment (e.g., the contamination of Lake Superior with cummingtonite-grunerite, as discussed in Bowes, Langer & Rohl, 1977), have been the subject of recent intensive investigations mostly due to their protential impact to large segments of the general population.

Surface reactivity in the pathogenic response to particulates.

“…A typical example is the variety of biological responses to the simple compound, silicon dioxide (1)(2)(3)(6)(7)(8)(9)18). The various crystalline silica polymorphs exhibit remarkable differences in their pathogenic potential related to differences in crystal structure (1,3,8,(19)(20)(21).…”

“…The molecular mechanisms by which particulates elicit a pathogenic response are still partly obscure even for well-established carcinogenic materials such as asbestos (11) or crystalline silica, which is one of the most fibrogenic dusts (7,18,76) and has been recently classified as carcinogenic to humans by the International Agency for Research on Cancer (42). This is partly because research in this field has proceeded in the following sequence, beginning with evidence of the association between exposure and pathogenicity of a given material: Pressure, torr An understanding of the last point for toxic particles and fibers whose toxicity is well established could be of great help in designing safer new materials to be used as substitutes for pathogenic ones.…”

“…Hemolysis of red blood cells was one of the first effects caused by mineral dusts to be extensively investigated over a large variety of specimens (5,6). Attention was then focused on the crystal faces exposed and on the chemical functionalities present at the surface (7)(8)(9). Few extensive reviews on the physicochemical properties of minerals relevant to biological activities appeared in the subsequent years (8)(9)(10); meanwhile, research proceeded much more on the biomedical…”

Does the Harvard/U.S. Environmental Protection Agency Ambient Particle Concentrator Change the Toxic Potential of Particles?

“…29,30 Crystalline silicas are of variable toxicity because of physical properties and structure. 27,31,32 These factors are important in the stimulation of macrophages to produce inflammatory and fibroproliferative factors. 33 Oxygen radicals are also important in the pathogenesis of SiO 2 -associated lung disease and may impair the ability of the macrophages to control infection, leading to increased risk of infectious disease such as tuberculosis in patients with silicosis.…”

Characterization by Scanning Transmission Electron Microscopy of Silica Particles from Alveolar Macrophages of Coal Miners

“…Furthermore, in vitro studies of the membranolytic activity and cytotoxicity of mineral dust particles have shown no unique relationship with the bulk concentration of quartz in such dusts (3)(4)(5). On the other hand, many in vitro and in vivo studies of the effect on cytotoxicity of the surface characteristics of mineral particles have shown positive correlations with different related variables (6)(7)(8)(9). Also, Rehn et al (10) have shown that the presence of admixed minerals affects the rate of elimination of inhaled dusts from the lung.…”