Identification of foreign material in lung by energy dispersive x-ray analysis. A new approach to silicosis.

Conventional methods for the detection of foreign material in the lungs are not only difficult but make it impossible to study any relationship between the material and the surrounding tissue. The present study employs energy dispersive x-ray analysis and scanning electron microscopy as the basis of a rapid and accurate method for determining the amount of silicon in the lungs of normal subjects and subjects with silicosis. A statistical evaluation of the data suggests that a silicon/sulfur ratio below 0.2 may be considered normal, whereas, a ratio above 0.3 may be considered to indicate silicosis.