Titanium dioxide nanoparticles: a review of current toxicological data

Area of Science:

• Nanotoxicology
• Environmental Health
• Materials Science

Background:

• Titanium dioxide nanoparticles (TiO2 NPs) are widely manufactured, exhibiting unique properties distinct from fine particles (FPs).
• Occupational exposure primarily occurs through inhalation, with potential translocation to systemic organs from the lungs and gastrointestinal tract (GIT).
• Other exposure routes include oral (food additives) and dermal (limited penetration of stratum corneum).

Purpose of the Study:

• To review the current toxicological knowledge of TiO2 NPs.
• To identify knowledge gaps concerning TiO2 NP health effects and exposure routes.
• To assess the impact of TiO2 NPs on various organ systems.

Main Methods:

• Literature review of existing studies on TiO2 NP toxicology.
• Analysis of data concerning inhalation, oral, dermal, and intravenous exposure routes.
• Evaluation of physicochemical properties influencing bioactivity.

Main Results:

• Inhalation is a primary exposure route, with long-term studies reporting lung tumors in rats.
• Intravenous exposure can lead to pathological lesions in the liver, spleen, kidneys, and brain, often at high doses.
• Limited evidence suggests TiO2 NPs do not significantly penetrate the skin's stratum corneum.

Conclusions:

• Significant knowledge gaps exist regarding the long-term health effects and epidemiological data for TiO2 NPs.
• High doses of TiO2 NPs are associated with systemic toxicity, necessitating further research into dose-response relationships.
• Understanding the toxicology of TiO2 NPs is crucial given their widespread industrial production and application.