In industrial settings, people can be exposed to titanium dioxide through inhalation. Inhalation exposure to titanium dioxide is exceedingly rare for most people. 

Titanium dioxide manufacturer: Billions

A  2023 study published in the journal Environmental Research, scientists examined the effect of titanium dioxide nanoparticles on important gut bacteria in mice. Their results showed “the growth inhibitory effects could be associated with cell membrane damage caused by titanium dioxide nanoparticles to the bacterial strains. Metabolomics analysis showed that TiO2 NPs caused alterations in multiple metabolic pathways of gut bacteria, such as tryptophan and arginine metabolism, which were demonstrated to play crucial roles in regulating gut and host health.” The researchers also found that four different neuroprotective metabolites “were significantly reduced” in urine and in vitro bacteria and vivo urine samples. The researchers concluded: “Increasing evidence implies that the gut microbiome plays a profound role in regulating host metabolism. Our results illustrated that TiO2 NPs hindered the growth of four beneficial gut bacterial strains.”

Inhaling high concentrations of titanium dioxide dust or fumes, which may occur in occupational settings — such as in the production or processing of products containing the mineral — may cause respiratory problems like coughing, wheezing and shortness of breath, in addition to eye and skin irritation.