title: Oxidant generation and toxicity of size-fractionated ambient particles in human lung epithelial cells.
abstract: Exposure to ambient particulate matter (PM) is associated with respiratory and cardiovascular disease and lung cancer. In this study, we used size fractionated PM samples (3-7, 1.5-3, 0.95-1.5, 0.5-0.95, and <0.5 microm), collected at four contrasting locations (three urban sites, one remote background) in the UK with a Sierra-Andersen high volume cascade impactor. The H(2)O(2)-dependent oxidant generating capacity of the samples was determined by electron spin resonance with 5,5-dimethyl-1-pyrroline-N-oxide spin trapping. In A549 human lung epithelial cells, we determined the cytotoxicity of samples by LDH assay, and interleukin-8 (IL-8) release as an indicator of their inflammatory potency. Oxidative DNA damage was measured by the formamido-pyrimidine-glycosylase (fpg)-modified comet assay. Marked contrasts were observed for all endpoints. Remote background PM showed the lowest oxidant potential, was neither cytotoxic nor genotoxic and did not increase IL-8 release. For the other samples, effects were found to depend more on sampling location than on size fraction. PM collected at high-traffic locations generally showed the strongest oxidant capacity and toxicity. Significant correlations were observed between the oxidant generating potential and all toxicological endpoints investigated, which demonstrates that measurement of the oxidant generating potential by ESR represents a sensitive method to estimate the toxic potential of PM.
authors.affiliation: Institut fur umweltmedizinische Forschung (IUF) an der Heinrich Heine Universitat Dusseldorf gGmbH, Germany.
authors.forename: Anton
authors.initials: A
authors.lastname: Wessels
authors.forename: Wolfram
authors.initials: W
authors.lastname: Birmili
authors.forename: Catrin
authors.initials: C
authors.lastname: Albrecht
authors.forename: Bryan
authors.initials: B
authors.lastname: Hellack
authors.forename: Erich
authors.initials: E
authors.lastname: Jermann
authors.forename: Gabriele
authors.initials: G
authors.lastname: Wick
authors.forename: Roy M
authors.initials: RM
authors.lastname: Harrison
authors.forename: Roel P F
authors.initials: RP
authors.lastname: Schins
mesh_terms: D045744:Cell Line, Tumor; D020552:Comet Assay; D004249:DNA Damage; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D016209:Interleukin-8 / Q000378:metabolism; D008168:Lung / Q000166:cytology* / Q000378:metabolism; D016877:Oxidants / Q000737:chemistry*; D018384:Oxidative Stress; D010100:Oxygen / Q000737:chemistry; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D019097:Spin Trapping
chemical_list: D016209:Interleukin-8; D016877:Oxidants; D052638:Particulate Matter; D006861:Hydrogen Peroxide; D010100:Oxygen