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...

Crocidolite, one of the most carcinogenic forms of asbestos, is mutagenic in cultured mammalian cells when assayed using a system that can detect multilocus deletions. In the present study, we examined the effect of buthionine sulfoximine (BSO) on mutation frequency and the formation of 8-hydroxydeoxyguanosine (8-OHdG) in human-hamster hybrid (A(L)) cells induced by crocidolite fibers in an att...

Background: Increased rates of death from asbestos related diseases have been reported in former workers and residents exposed to crocidolite (blue asbestos) at Wittenoom, Western Australia. Exposure to asbestos is associated with reduced static lung volumes, gas transfer and lung compliance, and a restrictive ventilatory abnormality. Methods: The effects of crocidolite exposure and smoking his...

To analyze the correlation between asbestos lung burden and lung cancer, lungs of 211 female cases with and without lung cancer were examined. Phase-contrast microscopic (PCM) counting of ferruginous (FBs) and uncoated fibers (UFs), which had length longer than 5 microns and aspect ratios greater than 3:1, revealed a significantly higher level of FBs plus UFs in urban lung cancer cases than urb...

We used transgenic mice carrying the lacI reporter gene to study the mutagenesis potential of asbestos crocidolite. The animals were exposed by nose-only inhalation to an aerosol containing 5.75 mg/m(3) crocidolite dust for 6 hr/day and 5 consecutive days. After 1, 4, and 12 weeks, we examined four end points: the cytology of bronchoalveolar lavage, the lung load of crocidolite, the hydrophobic...

Crocidante asbestos is known to cause cellular damage, leading to asbestosis, bronchogenic carcinoma, and mesothelioma in humans. The mechanism responsible for the carcinogenicity of asbestos is not known. Iron associated with asbestos is thought to play a role by catalyzing the formation of reactive oxygen species, which may cause DNA damage, leading to mutations and cancer. Here, we examined ...

This is a study of workers at a friction materials factory founded in 1898. Crocidolite was used only during two well defined periods before 1945. Apart from this, only chrysotile asbestos has been used. The mortality study dates from 1942 and extends to 1979. Over 99% of the population have been traced. Ten deaths from mesothelial tumours occurred. An analysis contrasting the observed number o...

The cytotoxic effects of asbestos are partly mediated by the production of free radicals, including nitric oxide (NO). SV40 has been suggested to synergize with asbestos in the pathogenesis of malignant mesothelioma. Crocidolite asbestos fibers induced in human mesothelial and malignant mesothelioma cells a significant increase of NO synthase activity and expression, which was absent in SV40-in...