环境地球化学国家重点实验室知识库

Biomass burning from the Indo-China Peninsula region is an important source of atmospheric mercury (Hg). We isolated 18 unique transport events over 2years using observations of Hg and CO at a high-altitude background site in southwestern China (Mount Ailao Observatory Station) to assess the transport and impact of Hg emissions from biomass burning. The quantity of Hg emission and the source regions were determined using TGM/CO slopes coupled with backward trajectory analysis and CO emission inventories. The slopes of TGM/CO appeared to be a useful chemical indicator for source identification. Industrial emission sources exhibited slopes in the range of 5.1-61.0x10(-7) (parts per trillion by volume, pptv/pptv), in contrast to a slope of 2.0-6.0x10(-7) for typical biomass burning. Transboundary transport of Hg from biomass burning led to episodically elevated atmospheric Hg concentrations during springtime. Hg emissions from biomass burning in the Indo-China Peninsula region from 2001 to 2008 were estimated to be 11.42.1Mgyr(-1), equivalent to 40% of annual anthropogenic emissions in the region. In addition, Hg emissions from biomass burning contained a substantial fraction of particulate bound Hg (PBM). Assuming that PBM readily deposits locally (within 50km), the local Hg deposition caused by the PBM was estimated to be 2.20.4Mgyr(-1), up to 1 order of magnitude higher than the PBM deposition caused by anthropogenic emissions during springtime in the region. The strong springtime emissions potentially pose a threat to the ecosystems of the Indo-China Peninsula and southwest China.