title: Exposure and toxicity assessment of ultrafine particles from nearby traffic in urban air in seoul, Korea.
abstract: OBJECTIVE
  We investigated the particle mass size distribution and chemical properties of air pollution particulate matter (PM) in the urban area and its capacity to induce cytotoxicity in human bronchial epithelial (BEAS-2B) cells.
  
  
  METHODS
  To characterize the mass size distributions and chemical concentrations associated with urban PM, PM samples were collected by a 10-stage Micro-Orifice Uniform Deposit Impactor close to nearby traffic in an urban area from December 2007 to December 2009. PM samples for in vitro cytotoxicity testing were collected by a mini-volume air sampler with PM10 and PM2.5 inlets.
  
  
  RESULTS
  The PM size distributions were bi-modal, peaking at 0.18 to 0.32 and 1.8 to 3.2 µm. The mass concentrations of the metals in fine particles (0.1 to 1.8 µm) accounted for 45.6 to 80.4% of the mass concentrations of metals in PM10. The mass proportions of fine particles of the pollutants related to traffic emission, lead (80.4%), cadmium (69.0%), and chromium (63.8%) were higher than those of other metals. Iron was the dominant transition metal in the particles, accounting for 64.3% of the PM10 mass in all the samples. We observed PM concentration-dependent cytotoxic effects on BEAS-2B cells.
  
  
  CONCLUSIONS
  We found that exposure to PM2.5 and PM10 from a nearby traffic area induced significant increases in protein expression of inflammatory cytokines (IL-6 and IL-8). The cell death rate and release of cytokines in response to the PM2.5 treatment were higher than those with PM10. The combined results support the hypothesis that ultrafine particles from vehicular sources can induce inflammatory responses related to environmental respiratory injury.
authors.affiliation: Institute for Environmental Research, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Ji-Yeon
authors.initials: JY
authors.lastname: Yang
authors.forename: Jin-Yong
authors.initials: JY
authors.lastname: Kim
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Jang
authors.forename: Gun-Woo
authors.initials: GW
authors.lastname: Lee
authors.forename: Soo-Hwan
authors.initials: SH
authors.lastname: Kim
authors.forename: Dong-Chun
authors.initials: DC
authors.lastname: Shin
authors.forename: Young-Wook
authors.initials: YW
authors.lastname: Lim
keywords: Cell toxicity; Transition metals; Ultrafine particles; Vehicle source