Clays in human tissues

Abstract

Methods of isolation and analysis of the particulate materials in the human tissues are reviewed. Since the relation of asbestiform minerals to human disease has been well documented, individual asbestos fibres and/or body cores in lung tissues have been sub-ject of observation by transmission electron microscope. Recently analytical electron microscope has been developed to facilitate observations for morphological and structural and chemical characteristics on the same specimen with an instantaneous switching. A carbon extraction technique used in association with analytical electron microscope provided evidence for the presence in the human tissues of quartz, sericite, talc, pyrophyllite, kaolin, diatomaceous material and some types of asbestos fibres. Applying a method of quantitative analysis for thin specimens by energy dispersive X-ray spectrometer, more than a quarter of the whole MgO contents leached out from chrysotile fibrils by their residence of 28 months in the rat lung.
The biological and tissue responses on exposure of asbestos fibres are also reviewed from a molecular biological viewpoint.