Deposition, Retention and Clearance, and Translocation of Inhaled Fine and Nano-Sized Particles in the Respiratory Tract
WOLFGANG G. KREYLING, OTMAR SCHMID, MANUELA SEMMLER-BEHNKE, and HOLGER SCHULZ Helmholtz Zentrum Mu¨nchen-German Research Center for Environmental Health, Institute for
The concept of dose is fundamental to the discipline of toxicology. For inhaled particles, dose considerations require information on particle deposition, retention, and clearance, and on particle translocation into circulation and secondary target organs. In this chapter, we summarize the state of knowledge on these processes with a particular focus on the increasing amount of ultrafine and nano-sized particles (NP), and we discuss the main governing parameters including environmental, particle, anatomic, and physiological factors. Although workplace exposure to airborne particles may play a significant role for specific professions (miners, welders, etc.), exposure to ambient particles is unavoidable for the whole population.