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Pulmonary bioassay studies with brake lining components - Nonfibrous potassium octatitanate - Terracess JS particles in rats. Food Chem Toxicol 2021; 153:112292. [PMID: 34052359 DOI: 10.1016/j.fct.2021.112292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 05/16/2021] [Accepted: 05/19/2021] [Indexed: 11/23/2022]
Abstract
Nonfibrous potassium octatitanate particles are commercially utilized in applications such as brake pads or brake linings. The aim of this study was to assess lung toxicity in rats exposed to Terracess JS particle-types, one form of nonfibrous octatitanate particulates, and compare the effects to vehicle controls and to Min-U-Sil α-quartz particles as a positive benchmark control particle. Groups of male rats were intratracheally instilled with doses of either 1 or 5 mg/kg of Terracess JS particles or α-quartz particles in phosphate-buffered saline. Phosphate-buffered saline (PBS) solution instilled rats served as vehicle controls. Following exposures, the lungs of PBS and particle-exposed rats were evaluated for bronchoalveolar lavage (BAL) fluid inflammatory biomarkers at post-instillation time points of 1 week, 1 month, and 3 months. In addition, lung tissue morphologies from PBS or 5 mg/kg particle-exposed (Terracess JS or α-quartz) rats were evaluated at postexposure time points of 1 month and 3 months. The BAL fluid results demonstrated that pulmonary instillation exposures in rats to quartz particles produced sustained pulmonary inflammation and significant cytotoxic effects measured at 1 week, 1 month and 3 months postexposure. In contrast, exposures to Terracess JS particle-types produced no significant lung inflammatory or cell injury effects when compared to PBS vehicle control exposed rats. With regard to histopathology of lung tissue, pulmonary exposures to quartz particles in rats produced a progressive, dose-dependent lung inflammatory response characterized by neutrophils and foamy lipid-containing alveolar macrophage accumulation, as well as evidence of early lung tissue thickening consistent with the development of pulmonary fibrosis at the 3-month postexposure time period. In contrast, histopathological analyses of lung tissues revealed that pulmonary exposures to Terracess JS particulates resulted in no significant adverse effects when compared to PBS-exposed controls, as evidenced by the normal lung architecture observed in the exposed animals at post-instillation exposure time periods ranging from 1 month to 3 months. The results described herein demonstrate the benign nature of the pulmonary instillation response in rats following particle exposures to 1 or 5 mg/kg (approximately 1.25 mg) of Terracess JS particle-types in these pulmonary bioassay studies, using appropriate benchmark control particles for comparative evaluations. Thus, based on these results, it is concluded that inhaled Terracess JS particles are expected to have a low-risk potential for producing adverse pulmonary health effects in exposed workers.
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Oyabu T, Myojo T, Lee BW, Okada T, Izumi H, Yoshiura Y, Tomonaga T, Li YS, Kawai K, Shimada M, Kubo M, Yamamoto K, Kawaguchi K, Sasaki T, Morimoto Y. Biopersistence of NiO and TiO₂ Nanoparticles Following Intratracheal Instillation and Inhalation. Int J Mol Sci 2017; 18:ijms18122757. [PMID: 29257061 PMCID: PMC5751356 DOI: 10.3390/ijms18122757] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 12/15/2017] [Accepted: 12/15/2017] [Indexed: 11/16/2022] Open
Abstract
The hazards of various types of nanoparticles with high functionality have not been fully assessed. We investigated the usefulness of biopersistence as a hazard indicator of nanoparticles by performing inhalation and intratracheal instillation studies and comparing the biopersistence of two nanoparticles with different toxicities: NiO and TiO2 nanoparticles with high and low toxicity among nanoparticles, respectively. In the 4-week inhalation studies, the average exposure concentrations were 0.32 and 1.65 mg/m3 for NiO, and 0.50 and 1.84 mg/m3 for TiO2. In the instillation studies, 0.2 and 1.0 mg of NiO nanoparticles and 0.2, 0.36, and 1.0 mg of TiO2 were dispersed in 0.4 mL water and instilled to rats. After the exposure, the lung burden in each of five rats was determined by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES) from 3 days to 3 months for inhalation studies and to 6 months for instillation studies. In both the inhalation and instillation studies, NiO nanoparticles persisted for longer in the lung compared with TiO2 nanoparticles, and the calculated biological half times (BHTs) of the NiO nanoparticles was longer than that of the TiO2 nanoparticles. Biopersistence also correlated with histopathological changes, inflammatory response, and other biomarkers in bronchoalveolar lavage fluid (BALF) after the exposure to nanoparticles. These results suggested that the biopersistence is a good indicator of the hazards of nanoparticles.
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Affiliation(s)
- Takako Oyabu
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
| | - Toshihiko Myojo
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
| | - Byeong-Woo Lee
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
| | - Takami Okada
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
| | - Hiroto Izumi
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
| | - Yukiko Yoshiura
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
| | - Taisuke Tomonaga
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
| | - Yun-Shan Li
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
| | - Kazuaki Kawai
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
| | - Manabu Shimada
- Department of Chemical Engineering, Hiroshima University, Higashi-Hiroshima 739-8528, Japan.
| | - Masaru Kubo
- Department of Chemical Engineering, Hiroshima University, Higashi-Hiroshima 739-8528, Japan.
| | - Kazuhiro Yamamoto
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Kenji Kawaguchi
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Takeshi Sasaki
- National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Yasuo Morimoto
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahata-nishi-ku, Kitakyushu, Fukuoka 807-8555, Japan.
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Biopersistence of NiO and TiO₂ Nanoparticles Following Intratracheal Instillation and Inhalation. Int J Mol Sci 2017. [PMID: 29257061 DOI: 10.3390/ijms18122757]] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The hazards of various types of nanoparticles with high functionality have not been fully assessed. We investigated the usefulness of biopersistence as a hazard indicator of nanoparticles by performing inhalation and intratracheal instillation studies and comparing the biopersistence of two nanoparticles with different toxicities: NiO and TiO₂ nanoparticles with high and low toxicity among nanoparticles, respectively. In the 4-week inhalation studies, the average exposure concentrations were 0.32 and 1.65 mg/m³ for NiO, and 0.50 and 1.84 mg/m³ for TiO₂. In the instillation studies, 0.2 and 1.0 mg of NiO nanoparticles and 0.2, 0.36, and 1.0 mg of TiO₂ were dispersed in 0.4 mL water and instilled to rats. After the exposure, the lung burden in each of five rats was determined by Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES) from 3 days to 3 months for inhalation studies and to 6 months for instillation studies. In both the inhalation and instillation studies, NiO nanoparticles persisted for longer in the lung compared with TiO₂ nanoparticles, and the calculated biological half times (BHTs) of the NiO nanoparticles was longer than that of the TiO₂ nanoparticles. Biopersistence also correlated with histopathological changes, inflammatory response, and other biomarkers in bronchoalveolar lavage fluid (BALF) after the exposure to nanoparticles. These results suggested that the biopersistence is a good indicator of the hazards of nanoparticles.
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Obata Y, Morimoto Y, Hirohashi M, Ogami A, Oyabu T, Myojo T, Kawanami S, Horie S, Nagatomo H, Murakami M, Tanaka I. Expression of Heme Oxygenase‐1 in the Lungs of Rats Exposed to Potassium Octatitanate Whiskers. J Occup Health 2011; 53:267-73. [DOI: 10.1539/joh.l10056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Yasuko Obata
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Yasuo Morimoto
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Masami Hirohashi
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Akira Ogami
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Takako Oyabu
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Toshihiko Myojo
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Shoko Kawanami
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Seichi Horie
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Hiroko Nagatomo
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Masahiro Murakami
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Isamu Tanaka
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
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Yamamoto M, Oyabu T, Morimoto Y, Ogami A, Kadoya C, Nishi KI, Todoroki M, Myojo T, Tanaka I. Biopersistence of potassium hexatitanate in inhalation and intratracheal instillation studies. Inhal Toxicol 2011; 23:196-204. [DOI: 10.3109/08958378.2011.558935] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Oyabu T, Ogami A, Morimoto Y, Myojo T, Murakami M, Yamato H, Tanaka I. Simple Flow‐through Solubility Measurement Apparatus and its Effectiveness for Hazard Assessment of Particles/Fibers. J Occup Health 2008; 50:279-82. [DOI: 10.1539/joh.m7009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Affiliation(s)
- Takako Oyabu
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Akira Ogami
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Yasuo Morimoto
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Toshihiko Myojo
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Masahiro Murakami
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Hiroshi Yamato
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
| | - Isamu Tanaka
- Institute of Industrial Ecological Sciences, University of Occupational and Environmental HealthJapan
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Grahame TJ, Schlesinger RB. Health effects of airborne particulate matter: do we know enough to consider regulating specific particle types or sources? Inhal Toxicol 2007; 19:457-81. [PMID: 17497526 DOI: 10.1080/08958370701382220] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Researchers and regulators have often considered preferentially regulating the types of ambient airborne particulate matter (PM) most relevant to human health effects. While few would argue the inherent merits of such a policy, many believe there may not yet be enough information to differentially regulate PM species. New evidence, using increasingly sophisticated methodologies, has become available in the last several years, allowing more accurate assessment of exposure and resultant associations with specific types of PM, or PM derived from different sources. Such new studies may also allow differentiation of effects from different chemical components in the same study against the same health endpoints. This article considers whether this new evidence might be adequate to allow us to "speciate" PM types or sources by severity of health effects. We address this issue with respect to two widespread sources of PM, emissions from motor vehicles and coal-fired power plants. Emissions from less widespread sources, residual oil and steel/coking facilities, are also discussed in order to illustrate how health effects associated with such emissions might instead be associated with more widespread sources when accurate exposure information is unavailable. Based upon evaluation of studies and methodologies which appear to contain the most accurate information on exposure and response to important emissions, including variable local emissions, it is concluded that public health will likely be better protected by reduction of various vehicular emissions than by continued regulation of the total mass of fine PM (PM <2.5 microm, or PM2.5) as if all PM in this mode is equitoxic. However, the knowledge base is incomplete. Important remaining research questions are identified.
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