Oxidative potential of coarse particulate matter (PM(10-2.5)) and its relation to water solubility and sources of trace elements and metals in the Los Angeles Basin.
Oxidative potential of coarse particulate matter (PM(10-2.5)) and its relation to water solubility and sources of trace elements and metals in the Los Angeles Basin.
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DOI：
10.1039/c5em00364d
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发表时间：
2015-12
期刊：
影响因子：
--
通讯作者：
Sioutas C
中科院分区：
文献类型：
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作者：
Shirmohammadi F;Hasheminassab S;Wang D;Saffari A;Schauer JJ;Shafer MM;Delfino RJ;Sioutas C
本研究确定了粗颗粒物(PM10-2.5，2.5<；dp<；10μm)中金属和微量元素的水溶态(WS)和水不溶态(WI)的潜在来源，并探讨了它们与粗颗粒物(CPM)氧化还原性能(ROS)的关系。CPM是在2012-2013年间在洛杉矶市中心和2013-2014年间在加利福尼亚州阿纳海姆收集的。一般来说，WI组分对CPM ROS活性的贡献较大(在中央LA和Anaheim，分别高达%和54%)。通过主成分分析确定了WS和WI组分的两个主要来源因素：车辆磨损和重新悬浮的道路粉尘。单因素分析表明，几种金属与CPM ROS活性相关：在WS组分中，Mn、Fe、Cd、Zn等金属与WS ROS活性相关，而在WI组分中，Ti、Fe、Ni、Pb、Cr与WS ROS活性的相关性最高。多元线性回归分析表明，车辆磨损和道路粉尘再悬浮都与WS ROS活性有关，而只有车辆磨损对WI ROS活性有显著影响。此外，与以往的研究相比，在过去的5年中，洛杉矶中部CPM的ROS活性有所增加。我们将这一增长主要归因于近年来该地区车辆速度和卡车数量的增加导致道路粉尘再悬浮水平上升，重申了非排气管交通排放对CPM毒性的日益重要。
In this study, potential sources of water-soluble (WS) and water-insoluble (WI) fractions of metals and trace elements in coarse particulate matter (CPM) (PM10–2.5, 2.5<dp<10 μm) were identified and their association with the redox properties of CPM, measured by means of reactive oxygen species (ROS), was explored. CPM was collected during 2012–2013 in Central Los Angeles (LA) and 2013–2014 in Anaheim, CA. Generally, WI components contributed to a larger fraction of CPM ROS activity (as much as 64% and 54% at Central LA and Anaheim, respectively). Two major source factors were identified by Principal Component Analysis for both the WS and WI fractions: vehicular abrasion and re-suspended road dust. Univariate analysis indicated that several species were correlated with CPM ROS activity: In WS fraction, metals such as Mn, Fe, Cd and Zn were associated with WS ROS, while in WI fraction Ti, Fe, Ni, Pb and Cr had the highest correlations with WI ROS activity. Multiple linear regression analysis revealed that both vehicular abrasion and re-suspension of road dust were associated with WS ROS activity, while only vehicular abrasion contributed significantly to the WI ROS activity. Moreover, comparison with previous studies indicated that the ROS activity of CPM has increased in the past 5 years in Central LA. We attribute this increase mainly to the elevated levels of re-suspension of road dust caused by the increase in vehicle speed and number of trucks in recent years in this area, reaffirming the growing importance of non-tailpipe traffic emissions on CPM toxicity.