Characterization of Food-Additive Titanium Dioxide and Dietary Exposure to Titanium Dioxide Nanoparticles among the Chinese Population.

Titanium dioxide (TiO 2 ) is a prevalent food additive, yet comprehensive data on particle size and dietary exposure are lacking in China. Transmission electron microscopy results revealed that the quantitative proportion of nanoparticles (NPs) in food-additive TiO 2 was 37.7%, with a mass fraction of 9.89%. Laboratory test results showed that among the domestic products surveyed, candies excluding gum-based candies contained the highest content of TiO 2 . Using consumption data from the China Health and Nutrition Survey in 2018, the average dietary exposure for TiO 2 and TiO 2 NPs in the Chinese population were calculated at 34.84 and 3.44 μg/kg bw/day, respectively. The primary dietary sources were puffed food and powdered drinks. Exposure varied significantly across age and region, with children and Inner Mongolia residents having the highest intake. TiO 2 NP exposure showed a negative correlation with age. Despite this, the dietary exposure risk of TiO 2 NPs for the Chinese population remains deemed acceptable.