title: Cytotoxic and proinflammatory effects of ambient and source-related particulate matter (PM) in relation to the production of reactive oxygen species (ROS) and cytokine adsorption by particles.
abstract: The composition of airborne particulate matter (PM) varies widely depending on its source, and recent studies have suggested that particle-associated adverse health effects are related to particle composition. The objective of this study was to compare the biological/toxicological effects of different source-related PM. Specifically, we investigated the biological/toxicological effects of standard reference materials (SRMs): non-ferrous dust (PD-1, industrial), urban PM (UPM, SRM1648a), and diesel PM (DPM, SRM2975), and ambient PM(2.5) (PM with an aerodynamic diameter <2.5 µm) collected at an urban site (Toronto, Canada). The dithiothreitol assay was used to measure the redox activity of the particles. Human alveolar epithelial cells (A549) were exposed to a range of concentrations (10-1000 µg/ml) of total PM, and the respective water-soluble and insoluble fractions, for 24 h. Biological responses were then evaluated in terms of cytotoxicity and interleukin (IL)-8 release, and compared with the PM composition and redox activity. We demonstrated that transition metal-enriched PD-1 exhibited the greatest cytotoxic effect (LD(50) values of 100-400 µg/ml vs. >1000 µg/ml for the SRM1648a, SRM2975, and ambient PM(2.5)). Similarly, the PM-induced release of IL-8 was greatest for PD-1 (~6-9 ng/ml vs. ~1.5-3 ng/ml for others). These endpoints were more responsive to metals as compared with compared with secondary inorganic ions and organic compounds. Interestingly, we demonstrated a high degree of adsorption of IL-8 to the various SRMs and ambient PM(2.5), and subsequently derived a new correction method to aid in interpretation of these data. These characteristics likely impart differential effects toward the toxic and immune effects of PM.
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada.
authors.forename: Umme S
authors.initials: US
authors.lastname: Akhtar
authors.forename: Robert D
authors.initials: RD
authors.lastname: McWhinney
authors.forename: Neeraj
authors.initials: N
authors.lastname: Rastogi
authors.forename: Jonathan P D
authors.initials: JP
authors.lastname: Abbatt
authors.forename: Greg J
authors.initials: GJ
authors.lastname: Evans
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Scott
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000633:toxicity*; D002170:Canada; D002460:Cell Line; D004784:Environmental Monitoring; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism*; D008168:Lung / Q000378:metabolism; D010084:Oxidation-Reduction; D052638:Particulate Matter / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D001335:Vehicle Emissions / Q000633:toxicity
chemical_list: D000393:Air Pollutants; D016209:Interleukin-8; D052638:Particulate Matter; D017382:Reactive Oxygen Species; D001335:Vehicle Emissions