Magnetic properties of high-road-side pine tree leaves in Beijing and their environ-mental significance

作     者：ZHANG Chunxia HUANG Baochun LI Zhenyu LIU He 

作者机构：Paleomagnetism and Geochronology Laboratory (SKL-LE) Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China 

出 版 物：《Chinese Science Bulletin》 (Chin. Sci. Bull.)

年 卷 期：2006年第51卷第24期

页      面：3041-3052页

核心收录：

学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 07[理学] 08[工学] 070602[理学-大气物理学与大气环境] 0706[理学-大气科学] 

基　　金：Acknowledgements The authors are grateful to Hu Shouyun  Pan Yongxin  Deng Chenglong and Liu Qingsong for helpful discussions and comments. Luo Rensong  Wang Hongqiang  Qin Huafeng  Xiao Bo and the other members in the Paleomagnetism and Geochronology Laboratory of the Institute of Geology and Geophysics  Chinese Academy of Sciences are also gratefully acknowledged for their contributions to this work. This work was supported by the National Natural Science Foundation of China (Grant Nos. 40525013  40221402) 

主　　题：公路 行道树 路侧树木 松树 树叶 交通污染 空气污染 磁学性质 

摘      要：This is a report on magnetic properties of highroad-side tree (Pinus pumila Regel) leaves collected along an expressway linking Beijing City and the Capital International Airport and further focus on their environmental contributions. A series of rock magnetic experiments show that the primary mag-netic mineral of leaf samples was identified to be magnetite,in the pseudo-single domain (PSD) grain size range 0.2―5.0 μm. On the other hand,magnet-ite concentration and grain size in leaves are ascer-tained to decrease with increasing of sampling dis-tance to highroad asphalt surface,suggesting that high magnetic response to traffic pollution is localized within a distance of some two meters away from highroad asphalt surface. Although magnetic suscep-tibility is ordinarily regarded as a simple,rapid and low-cost method for monitoring traffic pollution,saturation isothermal remanent magnetization (SIRM) can be treated as a valid proxy for monitoring air par-ticulate matter (PM) when samples are magnetically weak. It is believed that a synthetic rock magnetic study is an effective method for determining concen-tration and grain size of ferromagnets in the atmos-pheric PM,and then it should be a rapid and feasible technique for monitoring atmospheric pollution.