THE INFLUENCE OF THE SIZE OF QUARTZ DUST PARTICLES ON THE REACTION OF LUNG TISSUE*

Abstract

The effect of intratracheal administration of equals masses (50 mg) of nine samples of quartz dust of varying particle size from 0.7 to 35 μm, all produced in the same manner, has been investigated in rats in order to verify the differing data in the literature. After three months the wet weights of lung, hydroxyproline, total lipids, esterifid fatty acids, total cholesterol and phospholipids were determined, and histological examinations were made. The statistically-evaluated results confirmed the high potency of dust particles smaller than 5 μm, but showed also differenas between individual samples above and below this level The most sensitive indicators of the response of lung tissue are the values of total lipids and phospholipids. In agreement with the histological picture, the highest fibroplastic effect, i.e. the highest hydroxyproline value, was found in dust with particles smaller than 1 μm, although the lipid values were smaller than in dust with particles of 3–5 μm. A more detailed analysis of lung lipids seems necessary.