Bioassays of amosite, short-range (SR), intermediate-range (IR) or intermediate-range chrysotile asbestos in combination with the intestinal carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) were conducted with male and female Syrian golden hamsters. Amosite and both forms of chrysotile asbestos were administered at a concentration of 1% in pelleted diet for the entire lifetime of the hams...

Typical ferruginous bodies considered as asbestos bodies (AB) were collected from the lungs of 19 asbestos-exposed and 25 non-exposed urban subjects. Of the 319 body cores analysed by energy dispersive spectrometry (EDS), 315 were asbestos. The non-asbestos cores were talc and crystalline silica. 89.2% of the asbestos cores were commercial amphiboles (amosite/crocidolite), 7% were chrysotile an...

As well as fibre size, fibre chemistry is a determinant of toxicity of mineral fibres. On these grounds, a few years ago, the asbestos industry in Québec developed a process to modify the surface chemistry of chrysotile asbestos by fixing phosphorous atoms. The pleuropulmonary fibrogenicity and carcinogenicity of the native and surface treated chrysotile, called chrysophosphate, were tested. Bo...

The Mawat ophiolite complex is of Cretaceous period as a residue oceanic crust covers about 200 km2, Northeastern Iraq.. serpentinite rocks are exposed diapir in the northeastern suture Zagros zone Iraq near Beetwat village, field study and petrography reveal two types serpentinite, shear massive, with three serpentine varieties. affected by secondary processes such diagenesis, metamorphism hyd...

A standard material containing chrysotile asbestos for the validation of x-ray diffractometric quantitation was developed using an asbestos-containing building material i.e., perlite board. The board as the base material was crushed, pulverized, and homogenized. The homogeneity of the powder of perlite board was estimated by analysis of variance. The diffraction intensity values of the crystall...

Samples of the chrysotile taken during and after treatment by the wet dispersion process have been tested for their cytotoxic effect in vitro and the results compared with both a UICC chrysotile A sample and a dust prepared from a standard chrysotile textile yarn. Results were obtained from three different in vitro assay systems utilizing P388D1, V79-4 and A549 cells. A sample which still conta...

The asbestos contents of the lungs of former employees of an asbestos textile factory were determined at necropsy using a transmission electron microscope. Those who had died of mesothelioma were compared with a matched sample of those who had died of other causes. The predominant fibre processed in the factory was chrysotile, but crocidolite had also been used. The lung content was consistent ...

BACKGROUND Chrysotile from the mine in Balangero, Italy is considered to be free of tremolite. In a cohort study of miners and millers only two pleural cancers were reported, a finding considered to indicate that chrysotile has a low potency for inducing mesothelioma. However, follow-up ended in 1987 and white-collar workers and the employees of subcontractors were not studied. METHODS To com...

The interaction between chrysotile and three lysosomal enzymes (acid phosphatase, acid RNase and acid protease) in isolated lysosomal enzyme-rich preparations (LEP), from sheep alveolar macrophages maintained in the presence and absence of serum components or pulmonary surfactant at pH 5.0 and pH 7.0 for up to 22 days, is investigated. It is concluded that chrysotile does not inhibit or enhance...

The results of analysis of mineral fibres in lung tissues from 10 paraoccupational cases of malignant mesothelioma were compared with analysis obtained from seven cases of malignant mesotheliomas that had developed in gas mask workers. Nine of the paraoccupational cases were considered to have developed their tumours because of exposure to asbestos on their husbands' working clothes and one can...