Cal Baier-Anderson, Ph.D., is a Health Scientist.
In 2004, Gunter Oberdorster and colleagues demonstrated that upon inhalation, ultrafine particles, the dimensions of which are measured in nanometers, can move from the nasal passages of rodents to the brain via a specialized nerve called the olfactory bulb. The evolutionary purpose of the olfactory bulb is to relay information about odors directly and rapidly from the nose to the brain.
The extent to which rapid transit via the olfactory bulb is a significant potential route of exposure to engineered nanomaterials is still an open question. But two new papers add support for the relevance of this intriguing exposure pathway, raising important questions regarding the safety of inhaled nanoparticles.