"is a made up word [...] It has sometimes been used as a synonym for the occupational disease known as silicosis, but it should not be as most silicosis is not related to mining of volcanic dusts, and no evidence of silicosis has been found in populations exposed to crystalline silica in volcanic ash.

Clinical and toxicological research conducted on volcanic crystalline silica has found little to no evidence of its ability to cause silicosis/pneumoconiosis-like diseases and geochemical anlayses have shown that there are inherent factors in the crystalline structure which may render volcanic crystalline silica much less pathogenic than some other forms of crystalline silica." [Emphasis mine]