Nanosized TiO₂ caused minor airflow limitation in the murine airways.
The use of nanotechnology is increasing exponentially, whereas the possible adverse health effects of engineered nanoparticles (NPs) are so far less known. Standardized mouse bioassay was used to study sensory and pulmonary irritation, airflow limitation, and inflammation potency of nanosized TiO(2). Single exposure (0.5 h) to in situ generated TiO(2) (primary particle size 20 nm; geometric mean diameters of 91, 113, and 130 nm at mass concentrations of 8, 20, and 30 mg/m(3), respectively; crystal phase anatase + brookite (3:1)) caused airflow limitation in the conducting airways at each studied exposure concentration, which was shown as a reduction in expiratory flow, being at the lowest 73% of baseline. The response was not dose dependent. Repeated exposures (altogether 16 h, 1 h/day, 4 days/week for 4 weeks) to TiO(2) at mass concentration of 30 mg/m(3) caused as intense airflow limitation effect as the single exposures, and the extent of the responses stayed about the same along the exposure days. Sensory irritation was fairly minor. Pulmonary irritation was more pronounced during the latter part of the repeated exposures compared to the single exposures and the beginning of the repeated exposures. Sensory and pulmonary irritation were observed also in the control group, and, therefore, reaction by-products (NO(2) and C(3)H(6)) may have contributed to the irritation effects. TiO(2) NPs accumulated mainly in the pulmonary macrophages, and they did not cause nasal or pulmonary inflammation. In conclusion, the irritation and inflammation potencies of studied TiO(2) seemed to be low.
Department of Environmental Science, University of Eastern Finland, Kuopio, Finland. Maija.leppanen@uef.fi
Maija
M
Leppänen
Anne
A
Korpi
Mirella
M
Miettinen
Jani
J
Leskinen
Tiina
T
Torvela
Elina M
EM
Rossi
Esa
E
Vanhala
Henrik
H
Wolff
Harri
H
Alenius
Veli-Matti
VM
Kosma
Jorma
J
Joutsensaari
Jorma
J
Jokiniemi
Pertti
P
Pasanen
D000336:Aerosols; D000475:Alkenes / Q000378:metabolism; D000818:Animals; D021461:Animals, Outbred Strains; D002248:Carbon Monoxide / Q000378:metabolism; D002463:Cell Membrane Permeability; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D007509:Irritants / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D016676:Macrophages, Alveolar / Q000737:chemistry / Q000187:drug effects / Q000276:immunology / Q000648:ultrastructure; D008297:Male; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000008:administration & dosage / Q000737:chemistry / Q000633:toxicity*; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism; D010316:Particle Size; D012123:Pulmonary Ventilation / Q000187:drug effects*; D012137:Respiratory System / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure; D018689:Sensory System Agents / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*; D014025:Titanium / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics / Q000633:toxicity*
D000336:Aerosols; D000475:Alkenes; D007509:Irritants; D018689:Sensory System Agents; C009495:titanium dioxide; D009569:Nitric Oxide; D002248:Carbon Monoxide; C013658:propylene; D014025:Titanium