Particle size distributions of metal and non-metal elements in an urban near-highway environment
Particle size distributions of metal and non-metal elements in an urban near-highway environment
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DOI：
10.1016/j.atmosenv.2010.11.010
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发表时间：
2011-02-01
影响因子：
5
通讯作者：
Shaferd, Martin
中科院分区：
文献类型：
--
作者：
Hays, Michael D.;Cho, Seung-Hyun;Shaferd, Martin
由于其带来的健康和环境风险，确定公路附近颗粒物 (PM) 的尺寸分辨元素组成非常重要。在当前的研究中，使用位于北卡罗来纳州罗利州际公路 20 m 处的低压撞击器采集了 12 个 24 小时 PM 样本（2006 年 7 月至 8 月）。州际公路每天支持约 125,000 辆车辆，其中大部分是轻型汽油客车。整体近高速公路 PM 质量尺寸分布呈三峰分布，主要累积模式峰值位于 500-800 nm。 PM 质量水平反映了日常交通活动，而高速公路附近 PM10 (33 +/- 7.5 mu g m(-3))、PM2.5 (29 +/- 6.8 mu g m(-3)) 和 PM0.1 (1.4 +/- 0.3 mu g m(-3)) 平均质量水平在两周采样期内变化小于 24%。使用扇形磁感应耦合等离子体质谱 (SF-ICPMS) 研究了撞击器收集的 PM 的元素组成。累积模式硫 (7 +/- 4% w/w) 是在高速公路附近检测到的主要无机成分，其次是可能来自地壳物质再悬浮的粗模式 IA 组和 IIA 元素。正如预期的那样，在高速公路附近的 PM 中也发现了沥青、车辆、催化剂（例如 Pt、Rh 和 Pd）、制动器和轮胎磨损（例如 Cu 和 Sb）中经常检测到的元素。分别在 d(50) =1-2 μm、d(50) =1-4 μm 和 d(50) >= 1-4 μm 时观察到铂族元素、稀土元素以及常见制动器和轮胎磨损元素的最大浓度。被列为 EPA 空气毒物的 11 种金属（Mn、Cr、Sb、Ni、Pb、As、Co、Cd、Se 和 Be）中的 10 种在每种 PM 粒径级分中均被检测到，但通常在 PM0.1 中富集。在多种 PM 尺寸模式下发现了几种具有生物拮抗作用的金属（Cd、Cu 和 V）。其中一些金属随着富集度（例如镍、锌、镉、砷和铜）和颗粒尺寸的每日变化而表现出不稳定的尺寸分布，表明在高速公路附近环境中发生了多种排放和金属暴露情况。由爱思唯尔有限公司出版
Determination of the size-resolved elemental composition of near-highway particulate matter (PM) is important due to the health and environmental risks it poses. In the current study, twelve 24 h PM samples were collected (in July-August 2006) using a low-pressure impactor positioned 20 m from a Raleigh, North Carolina interstate. The interstate supported similar to 125,000 vehicles/d, the majority of which were light-duty gasoline passenger vehicles. The overall near-highway PM mass size distribution was trimodal with a major accumulation mode peak at 500-800 nm. PM mass levels reflected daily traffic activity, while mean near-highway PM10 (33 +/- 7.5 mu g m(-3)), PM2.5 (29 +/- 6.8 mu g m(-3)), and PM0.1 (1.4 +/- 0.3 mu g m(-3)) mass levels varied less than 24% over the two week sampling period. The elemental composition of the impactor-collected PM was investigated using magnetic sector inductively coupled plasma-mass spectroscopy (SF-ICPMS). Accumulation mode sulfur (7 +/- 4% w/w) was the major inorganic constituent detected at the near-highway site followed by coarse mode group IA and IIA elements likely from re-suspension of crustal matter. As expected, elements regularly detected in asphalt, vehicle, catalyst (e.g., Pt, Rh, and Pd), brake, and tire wear (e.g., Cu and Sb) were also found in the near highway PM. Maximum concentrations of the platinum group, rare earth, and common brake and tire wear elements were observed at d(50) =1-2 mu m, d(50) =1-4 mu m, and d(50) >= 1-4 mu m, respectively. Ten of the eleven metals listed as EPA air toxics (Mn, Cr, Sb, Ni, Pb, As, Co, Cd, Se, and Be) were detected in each PM size fraction but were generally enriched in PM0.1. Several biologically antagonistic suites of metals (Cd. Cu, and V) were found in multiple PM size modes. Some of these metals showed erratic size distributions with daily changes in enrichment (e.g., Ni, Zn, Cd, As, and Cu) and particle size, suggesting a variety of emissions and metal exposure scenarios occurring in the near-highway environment. Published by Elsevier Ltd.