Scientists analyzed research that examined how titanium dioxide nanoparticles interact with the brain for a 2015 review published in Nanoscale Research Letters. The researchers wrote: “Once the TiO2 NPs are translocated into the central nervous system through [certain] pathways, they may accumulate in the brain regions. For their slow elimination rates, those NPs could remain in the brain zones for a long period, and the Ti contents would gradually increase with repeated exposure.” After reviewing dozens of studies, the scientists concluded: “Long-term or chronic exposure to TiO2 nanoparticles could potentially lead to the gradually increased Ti contents in the brain, which may eventually induce impairments on the neurons and glial cells and lead to CNS dysfunction as a consequence.”
From a stability standpoint, lithopone, a fusion of zinc sulfide and artificially precipitated barite, is non-toxic and exhibits resilience to mild lyes and acids. However, it is incompatible with colors containing copper. Despite its strong covering power in oil, lithopone’s drying capabilities are notably limited, posing potential issues for artists. Notably, early experimentation with lithopone-based grounds instead of zinc white resulted in undesirable darkening, although this blackness receded upon drying. This unpredictable behavior has sparked debate among scientific communities, emphasizing the need for further exploration and understanding of this pigment.