Brussels, 9 January 2004
Nanoparticles are capable of penetrating the brain after being inhaled, according to a German researcher working in the US.
Günter Oberdörster and colleagues at the University of Rochester in New York monitored the progress of carbon particles 35 nanometres in diameter that had been inhaled by rats. The particles were detected in the olfactory bulb, the area of the brain that deals with smell, the day after inhalation, and levels continued to rise until the experiment ended after seven days.
In addition to fuelling concerns about the health effects of nanotechnology, the research may also lead to a fuller understanding of the impact of nanoparticles produced by diesel engines. Some scientists believe that inhaling diesel exhausts leads to respiratory and cardiac problems, possibly by causing a reaction in the lungs. Professor Oberdörster's research indicates that some nanoparticles may prompt a similar inflammatory reaction in the brains of rats, according to the journal 'Nature'.
Professor Oberdörster believes that the carbon nanoparticles in his experiments entered the brain of the rats by moving down the brain cells that pick up odours and transmit signals to the olfactory bulb. This theory is supported by the results of additional experiments in which researchers blocked one of the nostrils of a number of rats and monitored which side of the brain the nanoparticles reached.