Determination of mono-methyl mercury concentrations in air and atmospheric waters to investigate on factors influencing their variations

• Project/Area Number: 24710026
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Environmental dynamic analysis
• Research Institution: National Institute for Minamata Disease
• Principal Investigator: MARUMOTO Kohji 国立水俣病総合研究センター, 環境・疫学研究部, 主任研究員 (90371369)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2014: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2013: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: メチル水銀 / 大気 / 降水 / 光化学反応 / 経年変動 / 水銀 / 分割採水 / 大気粒子 / 大気液相

Outline of Final Research Achievements

Monitoring of mono-methyl mercury (MMHg) in air and atmospheric waters such as rainwater and experimental studies on chemical reactions of MMHg using simulated rainwater were carried out to obtain the knowledge on behaviors of atmospheric MMHg. The results of this study revealed that the MMHg concentrations in rainwater taken in cold season at Minamata became lower from year to year and MMHg concentrations in the first stage of a rain event were higher than those in the following stages. In simulated rainwater adjusted at pH4 using hydrochloric acid and nitric acid, MMHg was photochemically produced from acetaldehyde and inorganic Hg. This is because methyl radical which is produced from the photochemical reaction between acetaldehyde and nitric acid can be related to the MMHg production.

Research Products

• [Journal Article] Mercury speciation in wet deposition samples collected from a coastal area of Minamata Bay. (2014)
  • Author(s): Marumoto, K., Matsuyama, A.
  • Journal Title: Atmospheric Environment Volume: 86 Pages: 220-227
  • DOI: 10.1016/j.atmosenv.2013.12.011
  • Peer Reviewed
• [Journal Article] 揮散損失を低減した溶存揮発性水銀捕集用海水サンプラーの開発と揮散損失が水銀放出フラックスの見積もりに与える影響 (2012)
  • Author(s): 丸本幸治
  • Journal Title: 分析化学 Volume: 61 Pages: 1063-1072
  • NAID: 10031131691
  • Peer Reviewed
• [Presentation] 水俣市の降水中における総水銀濃度およびメチル水銀濃度の経年変動 (2014)
  • Author(s): 丸本幸治
  • Organizer: 第55回大気環境学会年会
  • Place of Presentation: 愛媛県松山市
  • Year and Date: 2014-09-17 – 2014-09-19
• [Presentation] 九州地方における大気中のガス状水銀と粒子状水銀の多地点同時観測（2012年春季） (2013)
  • Author(s): 12. 丸本幸治、伊礼聡、高見昭憲、兼保直樹、林 政彦
  • Organizer: 大気環境学会
  • Place of Presentation: 朱鷺メッセ:新潟コンベンションセンター
• [Presentation] Factors influencing seasonal variations in atmospheric concentrations of gaseous elemental Hg, gaseous oxidized Hg and particulate-bound Hg at a site in Minamata Bay area, Japan (2013)
  • Author(s): Kohji Marumoto
  • Organizer: International conference on mercury as a global pollutant, 2013
  • Place of Presentation: エジンバラ、イギリス
• [Presentation] 水俣市における大気中のガス状酸化態水銀および粒子状水銀の通年観測 (2012)
  • Author(s): 丸本幸治
  • Organizer: 大気環境学会
  • Place of Presentation: 神奈川大学
• [Remarks] 水俣市における大気中水銀の観測
  • URL: http://www.nimd.go.jp/kenkyu/Mercury_in_the_atmosphere/Mercury_in_the_atmosphere1.html