中文摘要：

本文以银杏树木年轮为研究材料，对采自临沂市区及郊区的两组银杏树轮样品，经室内处理后定量测定了银杏树轮中重金属铅元素的含量，研究了临沂市近三十年来城市大气环境中重金属铅的污染状况．测定结果表明．临沂市郊区的树木年轮中重金属铅的含量大致呈增大趋势，市区的树木年轮中铅的含量波动很大．结合采样点及周围环境、临沂市社会经济发展状况分析．认为郊区银杏树木年轮中的铅元素主要来源于枋河河水和大气、而市区银杏树木年轮中的铅元素含量主要来源于大气．与汽车尾气关系密切．通过对测定结果和临沂市大气及水环境中铅的污染源分析，提出了降低铅含量浓度．提高临沂市生态环境质量的措施．

英文摘要：

In order to study the latest 30 years＇ pollution of Pb which is one of the heavy metal elements in Linyi, the paper therefore was written on the basis of the research employing two groups of Gingko Trees in the urban and suburb of Linyi respectively as the samples to study the heavy metal content of their tree-rings by interior quantitative examination. The results showed that the content of Pb in the tree-rings in the suburbs of Linyi generally tended to increase while the content in urban fluctuated considerably. Combined with the sampling points and the surroundings as well as the socio-eeonomic development in Linyi, it is believed that the main source of Pb from the tree-rings in the suburbs is atmosphere and the Beng River. Meanwhile, the main source of that in urban is the atmosphere and vehicle exhaust. Upon the analysis of the results and the source of pollution such as water and atmosphere, measures are proposed concerning the decrease of the density of Pb and the increase of the ecological environmental quality in Linyi.