TiO2 particles in seafood and surimi products: Attention should be paid to their exposure and uptake through foods.

The sustainable development of nanotechnology requires a thorough understanding of the life cycle of synthesized nanomaterials, including environmental release, deposition, exposure, and potential health risks. Titanium dioxide (TiO2) materials containing nanosized TiO2 (nTiO2) are commonly used as food additives. Thus, dietary intake through foods is the most important route for the exposure of TiO2 materials. Given the toxic effects of nTiO2 on the gastrointestinal tract and other tissues, it is imperative to investigate their sources and concentrations in popular foods. Therefore, we conducted a survey on TiO2 particles in white-colored seafood and surimi products in Beijing. Our data indicated that the total Ti levels reached 6-12 μg/g (dry weight) in some white-colored seafood products, such as squid and cuttlefish, whereas relatively low concentrations were observed in jellyfish at approximately 1-3 μg/g (dry weight). For the locally favorite surimi-based food products in the market, the Ti concentrations ranged from 2 to 81 μg/g (dry weight). The exposure assessment showed that the average daily intake of TiO2 particles through foods varied from 0.02 to 3.09 μg TiO2/kgbw/day, reflected by the Ti concentrations in this study, and that young people of age 20-30 showed the highest exposure level. Together, these results show relatively high concentrations of TiO2 particles in some seafood and surimi products available in the market, and our findings therefore call for attention on TiO2 particle exposure and uptake through daily foods.