PNNL

Abstract

We have discovered that TiO2 minerals naturally present in coal quickly convert to titania suboxides, specifically Magnéli phases (TixO2x-1 with 4 = x = 9) during the coal’s heating/burning in coal-fired power plants. As a coal ash component, these Magnéli phases are subject to widespread distribution, likely globally. This family of previously overlooked, incidental submicron- down to nano-materials, is distributed via airborne and waterborne processes. We propose that Magnéli phases can be used as a tracer in the environment to indicate/map the distribution of solid state emissions from coal-burning industrial processes. In its first toxity testing, we have shown that nanoscale Magnéli phases have potential toxicity pathways that are not photoactive like TiO2 phases, but instead may be biologically active without photostimulation. Collectively, our findings strongly suggest that these unusual, widespread materials should be thoroughly tested for their toxicity in soils, sediments, and animals, and particularly in the human lung.