台灣平地大氣汞濃度之監測

Monitoring of Atmospheric Mercury Concentration at Surface Sites in Taiwan

許桂榮(Guey-Rong Sheu) ； 林建志(Chien-Chih Lin) ； 林能暉(Neng-Huei Lin)

《環境保護》 30卷1期 (2007/06) Pp. 1-10

https://doi.org/10.30017/EP.200706.0001

摘要

汞是一個全球性污染物，可以氣態元素汞形式經大氣之長程輸送而到達全球各角落，造成環境污染並危害人體健康，美國與歐盟都將汞列為具持久性及生物累積性的毒性污染物。對多數人而言，攝食含甲基汞的魚類，是汞進入人體之最主要途徑，但水體的汞及魚體的甲基汞則主要是源自於大氣汞的沈降。由大氣沈降的無機汞在水中經微生物之轉化而形成劇毒之甲基汞，再經由食物鏈之生物累積與生物放大作用，在魚體內累積至高濃度，經食用後進入人體。在台灣關於大氣汞濃度與時空分佈的研究尚不多見，因此本研究是針對台灣平地大氣汞濃度進行監測，以瞭解其在空間及時間之分布特性。大氣汞採樣在三個採樣點進行，分別位於桃園縣新屋鄉、中壢市以及復興鄉。結果顯示，在此研究期間新屋鄉的大氣總汞平均濃度為最高，中壢市次之，復興鄉為最低，分別為3.78(±1.44)，3.62(±1.35)，2.90(±0.70) ng m^(-3)。此外，新屋鄉與中壢市的大氣總汞濃度間的相關係數為0.85，顯示兩地大氣汞濃度的時間變動有著相同的趨勢；復興鄉大氣汞濃度與新屋鄉或與中壢市的測值之間則較不具相關性。就季節性變化而言，三個採樣點的大氣總汞濃度皆以夏季較低。研究結果也顯示，都會區與工業區的大氣汞濃度較鄉村與非工業區高。

關鍵字

氣態元素汞 ； 時空分佈 ； 人為排放

並列摘要

Mercury (Hg) is a global pollutant. It is transported worldwide in its gaseous elemental form via long-range atmospheric transport to cause environmental pollution and to damage human health. Both USA and Europe Union (EU) have listed Hg as a ”Persistent Bioaccumulative and Toxic Pollutants (PBTs).” The most common way people are exposed to Hg is by eating fish containing methylmercury (MeHg). Nevertheless, the Hg in water and the MeHg in fish are mainly originated from atmospheric Hg deposition. The deposited inorganic Hg is converted to highly toxic MeHg in aquatic environments by microorganisms. Via food web bioaccumulation and biomagnification, MeHg is accumulated to high concentration in fish and entered human body through consumption. In Taiwan, studies concerning concentrations of atmospheric Hg and its temporal and spatial distribution are rare. Hence, we report here the atmospheric Hg concentrations measured at various sites in Taiwan to discuss its temporal and spatial distribution. Atmospheric Hg samples were manually collected at Chungli, Fusing, and Sinwu in Taoyuan County in 2005 and 2006. The average atmospheric Hg concentrations for Sinwu, Chungli, and Fusing were 3.78(±1.44), 3.62(±1.35), and 2.90(±0.70) ng m^(-3), respectively. The correlation coefficient between atmospheric Hg concentrations measured at Sinwu and Chungli was 0.85, indicating similar temporal trends in atmospheric Hg at both sites. On the other hand, atmospheric Hg measured in Fusing did not show any correlation with those measured either in Chungli or Sinwu. Similar seasonal trend was observed at all sites, with lower atmospheric Hg concentration in summer. Moreover, results of this study indicated that, in Taiwan, atmospheric Hg concentrations were higher in urban and industrial areas than in rural and non-industrial areas.

並列關鍵字

Gaseous Elemental Mercury ； Temporal and Spatial Distribution ； Anthropogenic Emission