Occupational exposure to asbestos fiber of brake repair job (auto mechanics) has seldom been evaluated in Iran. Accordingly, we evaluated asbestos fiber concentrations in the breathing zone of auto mechanics between July 2008 and December 2008. The asbestos fiber concentrations of 60 personal air samples collected from 30 cars and trucks brake replacement and they were analyzed by phase-contras...

Asbestos and other mineral fibers are carcinogenic to humans and animals but differ from many carcinogens in that they do not induce gene mutations. An understanding of these interesting human carcinogens, therefore, is an important problem in cancer research. Asbestos and other fibers induce predominantly two types of cancers: mesotheliomas and bronchogenic carcinomas. Fiber size is an importa...

There has been great public concern about the adverse health effects resulting from the presence of asbestos fibers in municipal drinking water supplies. This article reviews and summarizes the experimental findings of 11 published papers that have evaluated the carcinogenic potential of asbestos following its ingestion. The long-term, high-level ingestion of various types of asbestos fibers in...

Over the past several years, the presence of fibrous asbestos particulates has been observed in a number of municipal water supplies throughout the USA, Canada, and several other regions all over the world. The possible health hazards which these fibers present have spurred a great deal of interest in the problems of detection and removal of the submicroscopic particulates in water. Asbestos is...

Studies on the behavior of asbestos fibers within tissues have shown that the only cells that regularly contain asbestos are macrophages and their derivatives. However, these cells actively incorporate the asbestos fibers by the process of phagocytosis, and there is little evidence of direct penetration. Examination of the gut lining after prolonged asbestos ingestion has shown no evidence of d...

Asbestos induces a constellation of biological responses in cells of the respiratory tract that are similar to those of classical tumor promoters. In this regard, induction of ornithine decarboxylase (ODC) activity and increased incorporation of [3H]thymidine have been documented after addition of crocidolite and chrysotile asbestos to a hamster tracheal epithelial cell line (J. M. Landesman an...

Examination of asbestos fibers by electron microscopical techniques enables the observer to distinguish among the fiber types by morphological and structural characteristics. Chrysotile asbestos fibers are composed of bundles of fibrils. Fibers are often curvilinear with splayed ends. Individual fibrils consist of a central capillary defined by an electron dense crystalline wall. With increasin...

“Asbestos” is a generic term that encompasses multiple fiber types but may mean different things, depending on the scientific discipline. This lack of consistency among asbestos research communities can lead to a disconnect when comparing studies in asbestos research. Differences in the interpretation of asbestos definitions between disciplines lead to discrepancies in the results and their int...

Although there have been a number of studies on the ingestion of asbestos, few studies exist on how the chrysotile asbestos itself is altered by the exposure to the acid stomach environment. This study has found that there are changes in the physical, chemical and surface properties of chrysotile asbestos as a result of exposure to water, strong acids, and simulated gastric juices. It was obser...

To investigate the role of iron and active oxygen species (AOS) in asbestos-induced fibrosis, we loaded increasing amounts of Fe(II)/Fe(III) onto the surface of amosite asbestos fibers and then applied the fibers to rat tracheal explants. Explants were harvested after 7 d in air organ culture. Asbestos by itself doubled procollagen gene expression, and a further increase was seen with increasin...