中文摘要：

环境大气中重金属元素通常存在于细颗粒物（PM2.5）中，对人体健康和生态环境具有潜在威胁．开展大气中重金属的监测对评估其环境健康影响以及针对性控制措施的制定具有重要科学意义和现实意义．本文对北京市怀柔区大气中20种重金属元素于2016年1月19日至3月4日进行了连续现场监测。并分析了大气重金属的污染现状、特征及来源．观测期间大气平均总重金属浓度为0．52μg·m^-3，约占PM2.5平均浓度（70．3μg·m^-3）的0．75％，其中以Fe、zn、Ba、Pb、Mn、Cu、Cd、As浓度较高；在2月8日（大年初一）烟花爆竹燃放高峰期间大气颗粒物中重金属元素浓度明显升高，总重金属浓度最高可达7．94μg·m^-3，占PM2.5的比例为9％，尤其以Ba、Pb、Cu、Zn、Mn、Cr浓度增长最为突出．以Fe作为地壳参比元素，发现怀柔冬季大气中Ni、Mn、Ga、cr的富集因子小于lO，其它元素的富集因子大于10，表明怀柔冬季大气中Ni、Mn、Ga、Cr主要来源于土壤或岩石风化，其它元素则主要来自人为污染源排放．基于怀柔冬季大气中不同重金属变化特征分析，推测Pb、Zn、Hg、Mn、Ni、Se与As共同来源于冬季燃煤采暖以及周围工业园区煤炭燃料燃烧排放，Cu、Pb、Cr、Zn、Mn和Ba主要来源于烟花爆竹燃放，Cd等元素来源于周围工业园区的工业生产过程．

英文摘要：

Atmospheric heavy metal elements are important components in fine particulate matter （ PM2.5 ） and have potential risks to human health and the environment. Therefore, monitoring of the ambient heavy metal elements is necessary in assessing the impact on environment. In this study, tweenty atmospheric heavy metal elements were monitored on site from 19th January to 4th March 2016 in Huairou District of Beijing. The results showed that the average concentration of the total heavy metal elements was 0.52 μg·m^-3 which accounted for 0.75% of PM2.5 mass concentration （70.3 μg·m^-3）. Fe,Zn,Ba,Pb,Mn,Cu,Cd and As were found to be the most abundant elements during the field measurement. The heavy metal elements, especially Ba, Ph, Cu, Zn, Mn and Cr increased sharply on 8 February （ the first day of Spring Festival） when the firework display was the most intensive. And their total concentration reached 7.94 μg. m^-3, accounting for 9% of PM2.5 mass concentration. To discern the possible sources for the atmospheric heavy metal elements, enrichment factors were calculated. The enrichment factors for Ni, Mn, Ga and Cr were below 10 by using Fe as the shell reference element, indicating that they mostly came from soil or rock decay. Other elements, with the enrichment factor above 10, might come from anthropogenie sources. The evident enrichment of Pb, Zn, Hg, Mn, Ni, Se and As was attriated to coal combustion for heating and peripheral industries. The main source of Cu, Pb, Cr, Zn, Mn and Ba could come from firework display, and the other heavy metal elements, especially Cd, were suspected to be from the industrial processes in the surrounding areas