Elemental content in alveolar septa in various pneumoconioses.

The elemental content of alveolar septa in various pneumoconioses was examind for a possible relationship to interstitial fibrosis. Silicon content, as well as heavy metal content, were evaluated to deterrmine possible interrelationships between the various inorganic dusts. Silicon levels were determined on the basis of silicon-sulphur ratios to accommodate for differences in tissue mass. A study of the variation of silicon-sulphur ratios in silicotics and normal individuals showed no false positives by our diagnostic criteria. A study of 11 cases of siderosis revealed that silicon was not responsible for the fibrosis as previously believed. An analysis of the lungs of 25 non-silicotic fibroses revealed that silicon-sulphur ratios were within normal limits. This technique should be useful in quantitating high exposure to certain dusts and in studying the relationship of such dusts to fibrosis.