title: Assessment of Pulmonary Toxicity Induced by Inhaled Toner with External Additives.
abstract: We investigated the harmful effects of exposure to a toner with external additives by a long-term inhalation study using rats, examining pulmonary inflammation, oxidative stress, and histopathological changes in the lung. Wistar rats were exposed to a well-dispersed toner (mean of MMAD: 2.1μm) at three mass concentrations of 1, 4, and 16 mg/m3for 22.5 months, and the rats were sacrificed after 6 months, 12 months, and 22.5 months of exposure. The low and medium concentrations did not induce statistically significant pulmonary inflammation, but the high concentration did, and, in addition, a histopathological examination showed fibrosis in the lung. Although lung tumor was observed in one sample of high exposure for 22.5 months, the cause was not statistically significant. On the other hand, a persistent increase in 8-OHdG was observed in the high exposure group, indicating that DNA damage by oxidative stress with persistent inflammation leads to the formation of tumorigenesis. The results of our studies show that toners with external additives lead to pulmonary inflammation, oxidative stress, and fibrosis only at lung burdens beyond overload. These data suggest that toners with external additives may have low toxicity in the lung.
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Taisuke
authors.identifier: 0000-0003-3583-3785
authors.initials: T
authors.lastname: Tomonaga
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Hiroto
authors.identifier: 0000-0003-0327-582X
authors.initials: H
authors.lastname: Izumi
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Yoshiura
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Myojo
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Oyabu
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Byeong-Woo
authors.initials: BW
authors.lastname: Lee
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Takami
authors.initials: T
authors.lastname: Okada
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Yunshan
authors.initials: Y
authors.lastname: Li
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Kazuaki
authors.identifier: 0000-0002-4724-2395
authors.initials: K
authors.lastname: Kawai
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Higashi
authors.affiliation: University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi, Kitakyushu 807-8555, Japan.
authors.forename: Yasuo
authors.identifier: 0000-0002-5339-6905
authors.initials: Y
authors.lastname: Morimoto
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000280:Administration, Inhalation; D000818:Animals; D001835:Body Weight; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004247:DNA / Q000378:metabolism; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D005260:Female; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D007958:Leukocyte Count; D008168:Lung / Q000473:pathology*; D009929:Organ Size; D009195:Peroxidase / Q000378:metabolism; D011327:Printing; D017208:Rats, Wistar; D013194:Staining and Labeling
chemical_list: D000080242:8-Hydroxy-2'-Deoxyguanosine; D004247:DNA; D009195:Peroxidase; D006419:Heme Oxygenase (Decyclizing); D003849:Deoxyguanosine