In designing a study to evaluate the inhalation biopersistence of a chrysotile asbestos that was used as a component of a joint-compound, a feasibility study was initiated to evaluate the short-term biopersistence of the chrysotile alone and of the chrysotile in combination with the sanded reformulated joint-compound. Two groups of Wistar rats were exposed to either 7RF3 chrysotile (Group 2) or...

X-ray powder diffractometry/Rietveld refinement was employed to estimate the purity of several chrysotile powders for calibrating standards. α-Corundum powder was mixed into each chrysotile sample as an internal standard. X-ray diffractometry was performed on these mixtures, and the mass fractions of amorphous and impurity phase content were calculated using Rietveld refinement. The chrysotile ...

A study of the interaction of phospholipid model membranes and red blood cell membranes with UICC A chrysotile fibres using chemical analysis and photoelectron spectrometry showed that the interaction agreed with an adsorption of the membranes on to the chrysotile fibres. The photoelectron spectrometry analysis allowed the statement that phospholipid model membranes are adsorbed as bilayer. Che...

The toxicity of sized and characterized chrysotile, crocidolite, and amosite preparations obtained from Dr. K. R. Spurny have been evaluated using alveolar macrophage (AM) migration inhibition assays and viability tests. These results have been compared with asbestos samples obtained from the National Institute of Environmental Health Sciences (NIEHS). These latter samples are designated chryso...

OBJECTIVES The potential applications and industrial production of multi-wall carbon nanotubes (MWCNT) have raised serious concerns about their safety for human health and the environment. The present study was designed to examine the in vitro cytotoxicity and genotoxicity of MWCNT and UICC chrysotile A (chrysotile). METHODS Cytotoxicity using both colony formation and lactate dehydrogenase (...

There is ongoing argument about the potency of chrysotile asbestos to cause malignant mesothelioma. Risk assessment for chrysotile is influenced by the alleged absence of mesotheliomas among workers at the Raybestos Manhattan friction products plant in Connecticut, a plant that essentially used only chrysotile asbestos. Regrettably, the statement that there is an absence of mesothelioma deaths ...

This paper describes a case control study investigating separately the lung cancer risk of exposure to chrysotile and to amphiboles. Logistic regression models were used to estimate separate exposure-response curves for the two fibre types, controlling for smoking. In the period longer than 15 years before lung cancer diagnosis, smokers above the 90th percentile of cumulative exposure to either...

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...

Beck, E. G., Holt, P. F., and Nasrallah, E. T. (1971). Brit. J. industr. Med., 28, 179-185. Effects of chrysotile and acid-treated chrysotile on macrophage cultures. The addition of chrysotile asbestos to monolayer cultures of peritoneal and alveolar macrophages produces an increase in membrane permeability, as measured by eosin uptake and lactic dehydrogenase activity of the supernatant fluid....

The risk of lung cancer related to asbestos exposure has been shown to increase disproportionately by cigarette smoking, suggesting a synergistic effect. Differing lengths of NIEHS chrysotile with benzopyrene [B(a)P, B(e)P] (organic by-products of combustion) were applied on normal human fibroblasts (cell line CI) to test for cytotoxicity (survival determined by colony-forming efficiency), bind...