Dosimetry and toxicology of inhaled ultrafine particles.
Both epidemiological and toxicological studies indicate that inhalation and subsequent deposition of airborne particles into the lungs have adverse health effects. Recently, the ultrafine particle (UfP) fraction (diameter < 100 nm) has received particular attention, as their small size may lead to more toxic properties. In this study we summarize the current knowledge on the dosimetry of inhaled particles (including UfPs) with a focus on recent data on translocation of UfPs into secondary target organs (such as brain and heart) suggesting that the lifetime dose of ambient UfPs in secondary target organs is about 10(11) particles. Furthermore, we highlight the main pathways of particle induced toxicity and the reasons for the potentially higher toxicity of UfPs. Finally, we discuss recent evidence indicating that (BET) surface area is the single most relevant dose metric for the toxicity of UfPs, which has important implications for regulatory measures on the toxicity of ambient and engineered particles.
Schmid
O
O
Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Lung Biology and Disease, Neuherberg, Germany. otmar.schmid@helmholtz-muenchen.de
Möller
W
W
Semmler-Behnke
M
M
Ferron
G A
GA
Karg
E
E
Lipka
J
J
Schulz
H
H
Kreyling
W G
WG
Stoeger
T
T
D000393:Air Pollutants / Q000378:metabolism / Q000633:toxicity*; D000818:Animals; D001822:Body Burden; D004305:Dose-Response Relationship, Drug; D006801:Humans; D019570:Inhalation Exposure; D008168:Lung / Q000187:drug effects / Q000378:metabolism; D010316:Particle Size; D052638:Particulate Matter / Q000378:metabolism / Q000633:toxicity*; D018570:Risk Assessment; D013499:Surface Properties; D014018:Tissue Distribution
D000393:Air Pollutants; D052638:Particulate Matter