DISTRIBUTION OF MINERALOGICAL PHASES IN DUSTS COLLECTED AT DIFFERENT WORKSHOPS

Dusts were collected by personal sampler on membrane filter from diffe rent workplaces. Respirable size (< 5 mum) and coarse fractions of air borne dust were separated by a cyclone. Only the respirable fraction c an penetrate into the deeper portions of the lung, therefore, the dist ribution of toxic minerals on the two fractions should be determined. Asbestos, quartz, calcite and albite content of dust was determined by IR-spectroscopy. Threshold limit values (TLV) measured for coal-mine workers were much higher than those which are permitted. Quartz concen trated in the coarse fractions while calcite usually accumulated in th e respirable fraction. In case of dusts collected at grave-stone polis hing cutting workshop, the amount of albite varied between 30 and 70 m /m% and no direct tendency was found concerning the distribution of al bite in the two fractions.