title: Spatial and seasonal heterogeneity of atmospheric particles induced reactive oxygen species in urban areas and the role of water-soluble metals.
abstract: Adverse health effects are associated with exposure to atmospheric particulate matter (PM), which carry various chemical constituents and induce both exogenous and endogenous oxidative stress. This study investigated the spatial and seasonal variability of PM-induced ROS at four sites with different characteristics in Hong Kong. Cytotoxicity, exogenous and endogenous ROS was determined on a dose and time dependent analysis. Large spatial variation of ROS was observed with fine PM at urban site showing highest ROS levels while coarse PM at traffic site ranks the top. No consistent seasonal difference was observed for ROS levels among all sites. The highly heterogeneous distribution of PM-induced ROS demonstrates the differential capability of PM to produce oxidative stress, and the need to use appropriate metrics as surrogates of exposure instead of PM mass in epidemiologic studies. Several transition metals were found associated with ROS by different degree illustrating the complexity of mechanisms involved.
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Hong Kong.
authors.forename: Nirmal Kumar
authors.initials: NK
authors.lastname: Gali
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Hong Kong.
authors.forename: Fenhuan
authors.initials: F
authors.lastname: Yang
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Hong Kong.
authors.forename: Sabrina Yanan
authors.initials: SY
authors.lastname: Jiang
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Hong Kong.
authors.forename: Ka Lok
authors.initials: KL
authors.lastname: Chan
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Hong Kong.
authors.forename: Li
authors.initials: L
authors.lastname: Sun
authors.affiliation: The Jockey Club, School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong.
authors.forename: Kin-fai
authors.initials: KF
authors.lastname: Ho
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Hong Kong. Electronic address: zhining@cityu.edu.hk.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Ning
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere / Q000737:chemistry*; D004784:Environmental Monitoring; D006723:Hong Kong; D008670:Metals / Q000032:analysis*; D018384:Oxidative Stress; D052638:Particulate Matter / Q000032:analysis*; D017382:Reactive Oxygen Species / Q000032:analysis* / Q000378:metabolism; D012621:Seasons; D014867:Water / Q000032:analysis
chemical_list: D000393:Air Pollutants; D008670:Metals; D052638:Particulate Matter; D017382:Reactive Oxygen Species; D014867:Water
keywords: Coarse PM; PM(2.5); Reactive oxygen species; Urban aerosol; Water-soluble metals