③ Paper making industry: Paper making and paper products industry is the third largest application industry of titanium dioxide. Paper using titanium dioxide has good whiteness, high strength, luster, thin and smooth, and is not easy to penetrate when printing. Under the same conditions, the opacity is 10 times higher than that of paper using calcium carbonate and talc powder, and the weight can also be reduced by 15% to 30%. The amount of titanium dioxide in decorative paper accounts for 20%~40% of its raw materials, and the amount of titanium dioxide in other papers is about 1%~5%. Due to the continuous adjustment of the industrial structure of the paper products industry from 2016 to 2018, according to the data of China Paper Association, the output of China's paper products in 2019 was 72.19 million tons, a significant year-on-year increase of 29.4%, and the use of titanium dioxide increased significantly.

In a 2016 study published in Scientifica (Cairo), Egyptian researchers examined the effects of titanium dioxide nanoparticles on the organs of mice by orally administering the food additive daily, for five days. The results showed that the exposure produced “mild to moderate changes in the cytoarchitecture of brain tissue in a time dependent manner.” Furthermore, “Comet assay revealed the apoptotic DNA fragmentation, while PCR-SSCP pattern and direct sequencing showed point mutation of Presenilin 1 gene at exon 5, gene linked to inherited forms of Alzheimer’s disease.” The researchers wrote: “From these findings, “the present study concluded that TiO2NPs is genotoxic and mutagenic to brain tissue which in turn might lead to Alzheimer’s disease incidence.”