School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea.
Sci Total Environ. 2011 Mar 15;409(8):1498-503. doi: 10.1016/j.scitotenv.2011.01.003. Epub 2011 Jan 28.
We investigated the effects of the East Asian Summer Monsoon (EASM), which brings approximately half of Korea's annual rainfall in July, on the concentration and particle-water partitioning, and sources of Hg in coastal waters. Surface seawater samples were collected from eight sites in Gwangyang Bay, Korea, during the monsoon (July, 2009) and non-monsoon dry (April and November, 2009) seasons and the concentrations of suspended particulate matter, chlorophyll-a, and unfiltered and filtered Hg were determined. We found significant (p<0.05) increases in filtered Hg in the monsoon season (1.8 ± 0.019 pM) compared to the dry season (0.62 ± 0.047 pM). In contrast, the Hg concentrations associated with particles showed no significant differences (p>0.05) between the monsoon (459 ± 141 pmol g(-1)) and the dry season (346 ± 30 pmol g(-1)), which resulted in decreased particle-water partition coefficients of Hg in the monsoon season compared to the values in the dry season: 5.7 ± 0.1 in April, 5.3 ± 0.1 in July, and 5.8 ± 0.1 in November. The annual Hg input to Gwangyang Bay was estimated at 64 ± 6.6 mol yr(-1) and 27 ± 1.9 mol yr(-1) for unfiltered and filtered Hg, respectively. The Hg discharged from rivers was a major source of Hg in Gwangyang Bay: the river input contributed 83 ± 13% of total input of unfiltered and 73 ± 6.0% of filtered Hg. On a monthly basis, unfiltered Hg input was 17 ± 11 mol month(-1) in the monsoon season and 3.2 ± 0.70 mol month(-1) in the dry season, while filtered Hg input was 7.1 ± 4.1 mol month(-1) in the monsoon and 1.3 ± 0.26 mol month(-1) in the dry. Consequently, the EASM resulted in an unfiltered Hg input 5.3 times greater than the mean dry month input and a filtered Hg input 5.5 times greater than the mean dry month input, which is mainly attributable to enhanced river water discharge during the monsoon season.
我们研究了东亚夏季风（EASM）对汞在沿海水体中的浓度、颗粒-水分配系数和来源的影响，东亚夏季风在 7 月为韩国带来了大约一半的年降雨量。在季风（2009 年 7 月）和非季风旱季（2009 年 4 月和 11 月）期间，我们从韩国光阳湾的 8 个地点采集了表层海水样本，并测定了悬浮颗粒物、叶绿素-a 和未过滤及过滤的汞浓度。我们发现，与旱季（0.62 ± 0.047 pM）相比，季风季（1.8 ± 0.019 pM）过滤汞的浓度显著增加（p<0.05）。相比之下，汞与颗粒的浓度之间没有显著差异（p>0.05）（季风季：459 ± 141 pmol g(-1)；旱季：346 ± 30 pmol g(-1)），这导致季风季汞的颗粒-水分配系数低于旱季：4 月 5.7 ± 0.1，7 月 5.3 ± 0.1，11 月 5.8 ± 0.1。光阳湾的年汞输入量估计分别为 64 ± 6.6 mol yr(-1)和 27 ± 1.9 mol yr(-1)，用于未过滤和过滤的汞。河流排放的汞是光阳湾汞的主要来源：河流输入对未过滤汞的贡献为 83 ± 13%，对过滤汞的贡献为 73 ± 6.0%。逐月来看，季风季未过滤汞的输入量为 17 ± 11 mol month(-1)，旱季为 3.2 ± 0.70 mol month(-1)，而季风季过滤汞的输入量为 7.1 ± 4.1 mol month(-1)，旱季为 1.3 ± 0.26 mol month(-1)。因此，EASM 导致未过滤汞的输入量是旱月平均输入量的 5.3 倍，过滤汞的输入量是旱月平均输入量的 5.5 倍，这主要归因于季风季河流水排放量的增加。
