Overview of current toxicological knowledge of engineered nanoparticles.

OBJECTIVE: Nanotechnology is the manipulation of matter on a near-atomic scale to produce nanoparticles with unique properties, allowing new commercial applications. Since nanoparticles exhibit unique physicochemical properties, they are likely to exhibit biological activity significantly different from fine-sized particles of the same chemical composition. Therefore, evaluation of the biological effects of nanoparticles is critical.
METHODS: The article lists the major objectives of nanotoxicology and briefly reviews the literature concerning biological responses to pulmonary exposure.
RESULTS: Interactions of nanoparticles with biological systems depend on particle size, shape, oxidant generation, surface functionalization, and rate of dissolution. Pulmonary, cardiovascular, and central nervous system responses to pulmonary exposure to nanotitanium dioxide and carbon nanotubes are described.
CONCLUSIONS: Significant biological responses occur in animal models after pulmonary exposure to certain nanoparticles. Control of exposure appears prudent to protect worker health. CLINICAL SIGNIFICANCE: Nanotechnology is synthesizing a wide range of nanoparticles, which exhibit unique physicochemical properties. These unique properties make unique biological activity likely. If certain nanoparticles induce adverse effects in vitro or in animal models, then occupational health surveillance and exposure control may be prudent steps in the protection of worker health.