Inorganic Particulates in Human Lung: Relationship to the Inflammatory Response
William S. Lynn in Inflammatory Cells and Lung Disease, 2019
The silicates comprise a large group of minerals which have the common feature of silicon atoms in a fourfold coordination with oxygen. Silicates may be further classified on the basis of crystallographic structure into six groups, depending on the arrangement of the silicon-oxygen tetrahedra in the crystal structure. The simplest arrangement, that of independent tetrahedral groups, is referred to as the nesosilicates. Sillimanite, referred to in the previous section, is a member of this group. Double tetrahedra structures characterize the group referred to as sorosilicates. Arrangement of the tetrahedra in the form of rings is characteristic of the cyclosilicates. Chain structures are found in the group known as inosilicates, which subclass includes the amphibole asbestos minerals (discussed in the previous section) as well as pyroxenes and pyroxenoids. The tetrahedra may be arranged in two dimensional sheets of indefinite extent, which form is characteristic of the phyllosilicates. This group includes serpentine, micas, and all the clay minerals. Finally, arrangement of the tetrahedra in three-dimensional networks characterizes the tektosilicates, which include the silica group (discussed in a previous section), the zeolite group (discussed in Section III.B), and the feldspars.99 The individual mineral species within each subclass differ primarily in the arrangement and substitution of various cations, such as sodium, magnesium, aluminum, potassium, calcium, or iron, within the basic crystal lattice.
Acute Lung Injury In Children Due To Chemical And Physical Agents
Lourdes R. Laraya-Cuasay, Walter T. Hughes in Interstitial Lung Diseases in Children, 2019
Two main groups of fibers are found, serpentines and amphiboles.417 The only serpentine, chrysotile (white asbestos), is the most common type (90% of all asbestos used) and is used in textile manufacture and related industrial processes.418 It is made of spirals of curved fibrils and, when inhaled, is deposited on proximal branching points of the tracheobronchial tree.417 Although chrysotile is cleared more rapidly than the other asbestos fibers from the tracheobronchial tree, it is more cytotoxic because of its high magnesium content.417 The amphiboles are used primarily in insulation applications. There are several, including cro-cidolite, amosite, anthophyllite, and tremolite.419 They are rectilinear fibrils of various dimensions that penetrate deeply into the lung.417 Fibers differ somewhat in fibrogenic potential, but even greater differences exist with regard to oncogenic potential so that crocidolite and amosite are associated with mesothelioma more often than the other fiber types.419 Tremolite is a common impurity in talc and other minerals417 and may be responsible for some lung disease associated with these agents.
Vinca rosea (Madagascar Periwinkle) and Adhatoda vesica (Malabar Nut)
Azamal Husen in Herbs, Shrubs, and Trees of Potential Medicinal Benefits, 2022
Ajmalicine exerted an antispasmodic effect (Taha et al., 2008). Furthermore, serpentine can reduce spasmodic properties (Hedhili et al., 2007). Oleanolic acid is a pentacyclic triterpenoid that can reduce inflammation in carrageenan and dextran‐induced edema in rats model (Huang et al., 2012). By inhibiting COX-2 catalyzed prostaglandin biosynthesis process, ursolic acid provides an anti-inflammatory effect at 50 µg/ml in human mammary epithelial cells (Subbaramaiah et al., 2000; Huang et al., 2009). Ursolic acid further blocks the NF-kB pathway via suppressing several proinflammatory cytokines and chemokines (Shanmugam et al., 2013). According to Fischer et al. (1990), DHBA has a significant antifeedant effect against the Mexican bean beetle (Epilachna varivestis). The biological properties of V. rosea against larvae of the gram pod borer, Helicoverpa armigera, was investigated (Lepidoptera: Noctuidae). Ethyl acetate leaf extract of V. rosea has been discovered to be an effective biopesticide. Deshmukh et al. also discovered that V. rosea had insecticidal capabilities (2010).
Profiles and potential health risks of heavy metals in polluted soils in NE-Iran
Published in Toxin Reviews, 2022
Masumeh Taheri, Mohamad Hosein Mahmudy Gharaie, Jalil Mehrzad, Michael Stone, Reza Afshari
The geology in the study area consists primarily of shale, marl, sandstone, conglomerate, and evaporates (gypsum and halite) of the Paleogene age. Several anticlines, synclines and folded beds are predominant in the region. East-west trending strike slip “Doruneh fault” is the main fault accompanied with N-W to S-E oblique-slip and normal faulting system in the region (Aghanabati 2004). The fractures in the region were filled by hydrothermal solutions can release small amounts of Au, Ag, Cu, Pb, and Zn. Epithermal mineralization of As, Sb, and Au at temperatures less than 300 °C has been reported (Mazloumi Bajestani 1992). Jarosite [KFe(SO4)2OH6] and alunite [KAl3(SO4)3OH6] together with montmorillonite and kaolinite are hydrothermally altered minerals, which indicate previous hydrothermal activities in this region. Mineralization of sulfides such as realgar, orpiment, pyrite, and stibnite are present with calcite and gypsum in the alteration zone, which named as argillic-pyrite alteration zone (Mazloumi Bajestani 1992). The mafic and ultramafic igneous rocks of the ophiolitic complex including peridotites, serpentinite, and pyroxenite in the western part of the region (Naderi Mighan 1999a) contain large amounts of heavy metals such as Ni, Cr, and Co.
Updated Italian cohort data continues to confirm lack of mesothelioma risk in pooled cohort of international cosmetic talc miners and millers
Published in Inhalation Toxicology, 2022
A. Michael Ierardi, Elizabeth A. Best, Gary M. Marsh
Cosmetic-grade talc (herein referred to as cosmetic talc) is widely regarded as “relatively pure” talc (Hildick-Smith 1976; IARC 1987; Zazenski et al. 1995; American Conference of Governmental Industrial Hygienists [ACGIH] 2001, p. 1; 2010; IARC 2010; Fiume et al. 2015; Drechsel et al. 2018). The Cosmetic, Toiletry, and Fragrance Association (CTFA), now known as the Personal Care Products Council (PCPC), noted that cosmetic talc “consists typically of 90% hydrated magnesium silicate” (CTFA 1976 b), while ACGIH more recently reported that talc used in cosmetics and pharmaceuticals is >98% and >99% pure, respectively (ACGIH 2010). Cosmetic talc is comprised of plates of a crystalline hydrated silicate of magnesium and, on occasion, other silicates, such as non-asbestiform serpentine or amphibole (e.g., anthophyllite and tremolite) minerals at low levels (Lightfoot et al. 1972; Pooley 1972, 1976; Rubino et al. 1976; Boundy et al. 1979; Rubino et al. 1979; Selevan et al. 1979; Parkes 1982; Wegman et al. 1982; Wergeland et al. 1990; Wild et al. 2002; Coggiola et al. 2003; Pira et al. 2017; Wergeland et al. 2017; Fordyce et al. 2019; Ciocan et al. 2022).
The toxicology of chrysotile-containing brake debris: implications for mesothelioma
Published in Critical Reviews in Toxicology, 2019
Craig A. Poland, Rodger Duffin
Rather than being a single entity, “asbestos” is a collective term for a group of naturally occurring silicate fibers and are broadly classified into serpentine or amphibole. The serpentine group consists only of chrysotile asbestos, a flexible and flowing fiber of thin chrysotile fibrils that can be woven while the amphibole group consists of five different forms of “asbestos”, namely crocidolite, amosite, tremolite, anthophyllite, and actinolite. Crocidolite and amosite asbestos were used commercially to some degree including significant usage in naval and merchant shipping as insulation materials in the form of asbestos filled mattresses, lagging and prior to 1963, sprayed asbestos (Harries 1968). However, of the different forms of “asbestos”, chrysotile was the most extensively used worldwide (Virta 2006). The availability and useful properties of chrysotile, amosite, and crocidolite asbestos fibers promoted their use in many different environments and products. Their lightweight, fireproofing, and insulating capacity made them indispensable in the technological revolution at the beginning of the twentieth century. “Asbestos” fibers such as chrysotile found uses in brake and clutch linings, insulation for fuel tanks for the growing aviation industry, cement boards and roofing tiles in the building industry and even as “artificial snow” sold to the public.