Characterization of Atmospheric Mercury Emission Sources and Transport in East Asia (Ii)

Mercury (Hg) is a global pollutant, which is distributed worldwide primarily via atmospheric long-range transport. It returns to Earth’s surface through wet and dry deposition entering terrestrial and aquatic ecosystems. Due to bioaccumulation and biomagnification along food chains, concentration of Hg could reach high level in fish and thus poses human health concerns. UNEP estimated that the global anthropogenic Hg emission was 1960 metric tons in 2010. East and Southeast Asia is the major emission source region, contributing about 40% of the global emission. China is the top emitter, contribution about 30% of the global emission. In recent years, massive Chinese haze events occur frequently and sometimes influence Taiwan via trans-boundary transport. These trans-boundary transported haze events may be accompanied by atmospheric Hg emitted in north, central and east China to Taiwan. Biomass burning is another important emission source, releasing 675 metric tons of Hg to the atmosphere each year. Indochina Peninsula is a major biomass burning region, with intense burning activities occurring between February and April. Data collected at the Lulin Atmospheric Background Station (LABS) indicate that biomass burning emissions from the Indochina Peninsula can influence the air quality in the mountain areas of Taiwan, resulting in elevated concentration air pollutants, such as CO, O3, aerosols, and Hg. During transport, the biomass burning plumes pass southwest and south China before entering Taiwan. As a result, in addition to the biomass burning emitted Hg, the biomass burning plume could also carry China’s anthropogenic Hg emission to Taiwan. Therefore, a 3-yr study plan is proposed to study the trans-boundary transport and impacts of atmospheric Hg in East Asia, including NE and SE Asia. In addition to the continuation of studies about biomass burning emission and transport, research about Chinese haze is newly added in response to its increasing occurring frequency and spatial scale. Intensive atmospheric Hg measurements (concentration and speciation) will be conducted at sites in the source region and the downwind receptor sites during the spring biomass burning season or the winter/spring haze occurring seasons via regional collaboration and participation of international experiments. Meteorological information, atmospheric radiation, and data of other air pollutants will be integrated with the Hg data to characterize the atmospheric Hg from different emission source regions. Moreover, physical and chemical behaviors of Hg during transport and the impacts of foreign Hg emissions on Taiwan will also be discussed. This proposal is prepared for application of the 2nd year’sresearch funding.