title: Comparison between whole-body inhalation and nose-only inhalation on the deposition and health effects of nanoparticles.
abstract: OBJECTIVE
  We performed the two inhalation exposures, whole-body inhalation and nose-only inhalation, to investigate the pulmonary deposition and health effects of the two inhalation methods.
  
  
  METHODS
  In both methods, we exposed rats to the same TiO2 nanoparticles at almost the same exposure concentration for 6 h and compared the deposited amounts of nanoparticles and histopathological changes in the lungs. Rats were exposed to rutile-type TiO2 nanoparticles generated by the spray-dry method for 6 h. The exposure concentration in the whole-body chamber was 4.10 ± 1.07 mg/m(3), and that in nose-only chamber was 4.01 ± 1.11 mg/m(3). The particle sizes were 230 and 180 nm, respectively. A control group was exposed to fresh air.
  
  
  RESULTS
  The amounts of TiO2 deposited in the lungs as measured by ICP-AES after acid digestion just after the exposure were: 42.6 ± 3.5 μg in the whole-body exposure and 46.0 ± 7.7 μg in the nose-only exposure groups. The histopathological evaluation was the same in both exposure groups: no infiltration of inflammatory cells in the alveolar space and interstitium, and no fibrosis.
  
  
  CONCLUSIONS
  The two inhalation methods using the same material under the same exposure conditions resulted in the same particle deposition and histopathology in the lung.
authors.affiliation: University of Occupational and Environmental Health, Japan, Kitakyushu, Japan. toyabu@med.uoeh-u.ac.jp.|Department of Environmental Health Engineering, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Japan, 1-1 Iseigaoka, Yahatanishi, Kitakyushu, 807-8555, Japan. toyabu@med.uoeh-u.ac.jp.
authors.forename: Takako
authors.initials: T
authors.lastname: Oyabu
authors.affiliation: University of Occupational and Environmental Health, Japan, Kitakyushu, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Morimoto
authors.affiliation: University of Occupational and Environmental Health, Japan, Kitakyushu, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Izumi
authors.affiliation: University of Occupational and Environmental Health, Japan, Kitakyushu, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Yoshiura
authors.affiliation: University of Occupational and Environmental Health, Japan, Kitakyushu, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Tomonaga
authors.affiliation: University of Occupational and Environmental Health, Japan, Kitakyushu, Japan.
authors.forename: Byeong-Woo
authors.initials: BW
authors.lastname: Lee
authors.affiliation: University of Occupational and Environmental Health, Japan, Kitakyushu, Japan.
authors.forename: Takami
authors.initials: T
authors.lastname: Okada
authors.affiliation: University of Occupational and Environmental Health, Japan, Kitakyushu, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Myojo
authors.affiliation: Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Shimada
authors.affiliation: Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Kubo
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamamoto
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kawaguchi
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sasaki
mesh_terms: D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D019570:Inhalation Exposure / Q000009:adverse effects*; D008168:Lung / Q000187:drug effects* / Q000473:pathology; D008297:Male; D053768:Metal Nanoparticles; D010316:Particle Size; D051381:Rats; D011916:Rats, Inbred F344; D013054:Spectrophotometry, Atomic; D014025:Titanium / Q000633:toxicity*; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D000393:Air Pollutants; C009495:titanium dioxide; D014025:Titanium
keywords: Deposition; Nose-only inhalation; TiO2 nanoparticle; Whole-body inhalation