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首页> 外文期刊>Journal of the air & waste management association >Historical trends in the mass and chemical species concentrations of coarse participate matter in the Los Angeles Basin and relation to sources and air quality regulations
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Historical trends in the mass and chemical species concentrations of coarse participate matter in the Los Angeles Basin and relation to sources and air quality regulations

机译：洛杉矶盆地粗物质参与物质的质量和化学物种浓度的历史趋势及其与源和空气质量法规的关系

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摘要

To assess the impact of past, current and proposed air quality regulations on coarse particulate matter (CPM), the concentrations of CPM mass and its chemical constituents were examined in the Los Angeles Basin from 1986 to 2009 using PM data acquired from peer reviewed journals and regulatory agency database. PM_(10) mass levels decreased by approximately half from 1988 to 2009 at the three sampling sites examined- located in downtown Los Angeles, Long Beach and Riverside. Annual CPM mass concentrations were calculated from the difference between daily PM_(10) and PM_(2.5) from 1999 to 2009. High CPM episodes driven by high wind speed/ stagnant condition caused year-to-year fluctuations in the 99th/98th percentile CPM levels. The reductions of average CPM levels were lower than those of PM_(10) in the same period, therefore the decrease of PM_(10) level was mainly driven by reductions in the emission levels of PM_(2.5) (or fine) particles, as demonstrated by the higher annual reduction of average PM_(2.5) (0.92 μg/m~3) compared with CPM (0.39 μg/m~3)from 1999 to 2009 in downtown Los Angeles despite their comparable concentrations. This is further confirmed by the significant decrease of Ni, Cr, V,and EC in the coarse fraction after 1995. On the other hand, the levels of several inorganic ions (sulfate, chloride and to a lesser extent nitrate) remained comparable. From 1995 to 2008, levels of Cu, a tracer of brake wear, either remained similar or decreased at a smaller rate compared with elements of combustion origins. This differential reduction of CPM components suggests that past and current regulations may have been more effective in reducing fugitive dust (Al, Fe and Si) and combustion emissions (Ni, Cr, V, and EC) rather than CPM from vehicular abrasion (Cu) and inorganic ions (NO_3~-, SO_4~(2-) and Cl~-) in urban areas. Implications: Limited information is currently available to provide the scientific basis for understanding the sources and physical and chemical variations of CPM, and their relations to air quality regulations and adverse health effects. This study investigates the historical trends of CPM mass and its chemical components in the Los Angeles Basin to advance our understanding on the impact of past and current air quality regulations on the coarse fraction of PM. The results of this study will aid policy makers to design more targeted regulations to control CPM sources to ensure substantial protection of public health from CPM exposure. Supplemental Materials: Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for (1) details of the sampling sites and (2) the daily concentrations of high CPM/PM_(10) episodes.
机译：为了评估过去，当前和拟议的空气质量法规对粗颗粒物（CPM）的影响，使用从同行审阅的期刊和期刊获得的PM数据，对1986年至2009年在洛杉矶盆地的CPM质量浓度及其化学成分进行了检查。监管机构数据库。从1988年到2009年，在洛杉矶市中心，长滩和河边的三个采样点，PM_（10）的质量水平下降了大约一半。根据1999年至2009年每日PM_（10）和PM_（2.5）之间的差值计算出每年的CPM质量浓度。高风速/停滞状态驱动的高CPM发作导致第99/98％CPM逐年波动水平。平均CPM水平的降低低于同期PM_（10）的降低，因此PM_（10）水平的降低主要是由于PM_（2.5）（或细颗粒）的排放水平降低所致。在1999年至2009年期间，尽管洛杉矶市中心的PM_（2.5）（CPM）浓度（CPM）（0.39μg/ m〜3）与CPM（0.39μg/ m〜3）相比，年均降低幅度更大，但其浓度却相当。 1995年以后，粗颗粒中镍，铬，钒和EC的显着下降进一步证实了这一点。另一方面，几种无机离子（硫酸根，氯离子和较小程度的硝酸根）的含量仍然相当。从1995年到2008年，与燃烧起源的元素相比，作为制动磨损示踪剂的Cu的含量保持相似或下降的速率较小。 CPM成分的这种差异性降低表明，过去和当前的法规可能比减少车辆磨损（Cu）的CPM更有效地减少了扬尘（Al，Fe和Si）和燃烧排放物（Ni，Cr，V和EC）。和城市地区的无机离子（NO_3〜-，SO_4〜（2-）和Cl〜-）。启示：目前可获得的信息有限，可为了解CPM的来源，物理和化学变化及其与空气质量法规和不良健康影响的关系提供科学依据。这项研究调查了洛杉矶盆地CPM质量及其化学成分的历史趋势，以加深我们对过去和当前空气质量法规对PM粗粒含量的影响的理解。这项研究的结果将帮助决策者设计更有针对性的法规，以控制CPM来源，以确保从CPM暴露中获得对公共卫生的实质性保护。补充材料：本文提供补充材料。转到《空气与废物管理协会杂志》的出版商在线版本，以了解（1）采样地点的详细信息和（2）高CPM / PM_（10）事件的每日浓度。

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  • 来源
    《Journal of the air & waste management association》 |2012年第5期|p.541-556|共16页
  • 作者

    Kalam Cheung; Martin M. Shafer; James J. Schauer; Constantinos Sioutas;

  • 作者单位

    Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA, USA;

    University of Wisconsin-Madison, Environmental Chemistry and Technology Program, Madison, WI, USA;

    University of Wisconsin-Madison, Environmental Chemistry and Technology Program, Madison, WI, USA;

    3620 South Vermont Avenue, KAP 210, Los Angeles, CA 90089, USA;

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