Abstract：
To explore air contamination resulting from special biomass combustion and suspended dust in Lhasa, the present study focused on the size distribution and chemical characteristics of particulate matter (PM) emission resulting from 7 types of non-fossil pollution sources. We investigated the concentration and size distribution of trace elements from 7 pollution sources collected in Lhasa. Combining Lhasa\'s atmospheric particulate matter data, enrichment factors (EFs) have been calculated to examine the potential impact of those pollution sources on the atmosphere quality of Lhasa. The highest mass concentration of total elements of biomass combustion appeared at PM0.4, and the second highest concentration existed in the size fraction 0.4-1 µm; the higher proportion (12 %) of toxic metals was produced by biomass combustion. The elemental composition of suspended dust and atmospheric particulate matter was close (except for As and Cd); the highest concentration of elements was all noted in PM2.5-10 (PM3-10). Potassium was found to be one of the main biomass markers. The proportion of Cu in suspended dust is significantly lower than that of atmospheric particulate matter (0.53 % and 3.75 %), which indicates that there are other anthropogenic sources. The EFs analysis showed that the Cr, Cu, Zn, and Pb produced by biomass combustion were highly enriched (EFs > 100) in all particle sizes. The EFs of most trace elements increased with decreasing particle size, indicating the greater influence of humanfactors on smaller particles.
摘要：
为了探索拉萨特殊生物质燃烧和悬浮粉尘造成的空气污染，本研究集中于7种非化石污染源产生的颗粒物（PM）排放的尺寸分布和化学特征。我们调查了拉萨收集的7个污染源的微量元素浓度和大小分布。结合拉萨大气颗粒物数据,已计算出富集因子（EF），以检查这些污染源对拉萨大气质量的潜在影响。生物质燃烧总元素的最高质量浓度出现在PM0.4，第二高浓度存在于0.4-1µm的尺寸分数中；生物质燃烧产生的有毒金属比例较高（12％）。悬浮粉尘和大气颗粒物的元素组成接近（As和Cd除外）；PM2.5-10（PM3-10）中元素浓度最高。发现钾是主要的生物质标志物之一。悬浮粉尘中Cu的比例明显低于大气颗粒物(0.53%和3.75%),这表明还有其他人为来源。EF分析表明，Cr，Cu,Zn,生物质燃烧产生的Pb在所有粒径下都高度富集(EFs>100)。大多数微量元素的EF随粒径的减小而增加，表明人为因素对较小颗粒的影响更大。
