title: Lung function changes in Sprague-Dawley rats after prolonged inhalation exposure to silver nanoparticles.
abstract: The antimicrobial activity of silver nanoparticles has resulted in their widespread use in many consumer products. However, despite the continuing increase in the population exposed to silver nanoparticles, the effects of prolonged exposure to silver nanoparticles have not been thoroughly determined. Accordingly, this study attempted to investigate the inflammatory responses and pulmonary function changes in rats during 90 days of inhalation exposure to silver nanoparticles. The rats were exposed to silver nanoparticles (18 nm diameter) at concentrations of 0.7 x 10(6) particles/cm(3) (low dose), 1.4 x 10(6) particles /cm(3) (middle dose), and 2.9 x 10(6) particles /cm(3) (high dose) for 6 h/day in an inhalation chamber for 90 days. The lung function was measured every week after the daily exposure, and the animals sacrificed after the 90-day exposure period. Cellular differential counts and inflammatory measurements, such as albumin, lactate dehydrogenase (LDH), and total protein, were also monitored in the acellular bronchoalveolar lavage (BAL) fluid of the rats exposed to the silver nanoparticles for 90 days. Among the lung function test measurements, the tidal volume and minute volume showed a statistically significant decrease during the 90 days of silver nanoparticle exposure. Although no statistically significant differences were found in the cellular differential counts, the inflammation measurements increased in the high-dose female rats. Meanwhile, histopathological examinations indicated dose-dependent increases in lesions related to silver nanoparticle exposure, such as infiltrate mixed cell and chronic alveolar inflammation, including thickened alveolar walls and small granulomatous lesions. Therefore, when taken together, the decreases in the tidal volume and minute volume and other inflammatory responses after prolonged exposure to silver nanoparticles would seem to indicate that nanosized particle inhalation exposure can induce lung function changes, along with inflammation, at much lower mass dose concentrations when compared to submicrometer particles.
authors.affiliation: Korea Environment & Merchandise Testing Institute, Incheon, Korea.
authors.forename: Jae Hyuck
authors.initials: JH
authors.lastname: Sung
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Ji
authors.forename: Jin Uk
authors.initials: JU
authors.lastname: Yoon
authors.forename: Dae Seong
authors.initials: DS
authors.lastname: Kim
authors.forename: Moon Yong
authors.initials: MY
authors.lastname: Song
authors.forename: Jayoung
authors.initials: J
authors.lastname: Jeong
authors.forename: Beom Seok
authors.initials: BS
authors.lastname: Han
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Han
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Chung
authors.forename: Jeongyong
authors.initials: J
authors.lastname: Kim
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Kim
authors.forename: Hee Kyung
authors.initials: HK
authors.lastname: Chang
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Lee
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Il Je
authors.initials: IJ
authors.lastname: Yu
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D007249:Inflammation / Q000139:chemically induced; D019570:Inhalation Exposure / Q000009:adverse effects*; D008168:Lung / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D008171:Lung Diseases / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D053768:Metal Nanoparticles / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012129:Respiratory Function Tests; D012834:Silver / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D012834:Silver