Differences in lung effects resulting from chrysotile and crocidolite exposure

Abstract

Crocidolite asbestos exposure may carry a greater risk for the development of lung and pleural tumours than chrysotile exposure, although differences in regard to lung fibrosis have not previously been demonstrated. Clinical, radiographic and physiological indicators of lung disease were related to qualitative and quantitative estimates of past total dust exposure in two groups of workers who had spent 20 to 30 years in the asbestos cement industry. One group had exposure to chrysotile, silica and crocidolite in the pipe-making area; the other group had no crocidolite exposure. Crocidolite exposure was related to the prevalence of small irregular opacities and pleural thickening but not to small rounded opacities. The "crocidolite" group had significantly small lung volumes, lower forced expiratory flows, and reduced pulmonary diffusion. Finger clubbing was the only clinical fineing significantly more prevalent in the crocidolite-exposed workers. It is suggested that crocidolite exposure has a greater fibrogenic effect on the lungs than a similar total exposure to chrysotile asbestos.