Freshwater algae show low-to-moderate susceptibility to TiO₂ exposure, with more pronounced toxic effects in the presence of UV irradiation. It has also been shown that nano-sized TiO₂ is significantly more toxic to algae Pseudokirchneriella sub-capitata than submicron-sized TiO₂. Hund-Rinke and Simon  reported that UV irradiated 25 nm TiO₂ NPs are more toxic to green freshwater algae Desmodesmus subspicatus than UV irradiated 50 nm particles, which is in agreement with Hartmann et al. UV irradiated TiO₂ NPs also inactivated other algae species such as Anabaena, Microcystis, Melsoira and Chroococcus. It was demonstrated that smaller particles have a greater potential to penetrate the cell interior than submicron-sized particles and larger aggregates. Studies have shown that the amount of TiO₂ adsorbed on algal cells can be up to 2.3 times their own weight.

Food recalls:Some Jif peanut butter products recalled over salmonella outbreak concerns 

Production[edit]

Asia

Infrared analysis showed that the characteristics bands for the bare nanoparticles are still exhibited in the vitamins@P25TiO₂NPs spectra, such as a wide peak in 450–1028 cm⁻¹ related to the stretching vibration of Ti-O-Ti and other peaks in 1630 cm⁻¹ and 3400 cm⁻¹, which represent the surface OH groups stretching. The IR spectrum of vitaminB2@P25TiO₂NPs showed signs of binding between compounds. The OH bending peak (1634 cm⁻¹) corresponding to bare nanoparticles disappeared, and the NH₂ bending band characteristic of vitamin B2 appeared (1650 cm⁻¹). The IR spectrum of vitaminC@P25TiO₂NPs also showed signs of successful functionalization. Bands at 1075 cm⁻¹; 1120 cm⁻¹; 1141 cm⁻¹ were observed, which are originated by CO-C vibrations present in the vitamin C. The intense band at 1672 cm⁻¹ is attributed to the C = O stretching in the lactone ring while the peak at 1026 cm⁻¹ is ascribed to the stretching vibration Ti-O-C. Wide bands at 3880–3600 cm⁻¹ are related to stretching vibration OH groups, but those disappear in the modified nanoparticles spectrum. These observations confirm the interactions between the P25TiO₂NPs and the vitamins [35].