Quantitative relationship of fecal asbestos to asbestos exposure

Abstract
A method is described for isolating chrysotile fibers from feces and counting them with an electron microscope. The detection limit was 150,000 fibers per gram feces; average recovery was 85.5%. When the method was used to check the asbestos in feces of people subjected to industrial exposure vs. controls, the means were significantly different (p < 0.02). Duplicate fecal samples were found to check within an average of ±31.1% of their means.