Two Centuries of Coral Skeletons from the Northern South China Sea Record Mercury Emissions from Modern Chinese Wars

• DOI: 10.1021/acs.est.5b05965
• Publication Date: 2016-05-13T09:11:25Z
• Authors: Ruoyu Sun; Holger Hintelmann; Yi Liu; Xiaohua Li; Brian Dimock
• Keywords: Mercury; Historical record

The contemporary mercury (Hg) cycle in the world's oceans has been greatly affected by human activities. However, we are still lacking reliable, long-term, and continuous records of Hg seawater. Here, report for first time on using annually banded Porites coral skeletons from northern South China Sea (SCS) as an archive recording changes seawater dissolved spanning past two centuries. We developed a combustion-trapping method to preconcentrate ultratrace concentrations aragonitic highly accurate total measurements. Results show that ranges 0.3 5.1 pmol/g is discriminated against Ca during skeletal calcification. Preindustrial (1798-1832) levels were found be approximately 0.5 pmol/g. highest (3-5 pmol/g) observed WWII period (1933-1942). Other distinct maxima (∼3 periods 1833-1847, 1858-1862, 1918-1927, 1978-1982, 1988-1992, with four coinciding Chinese wars. Our study suggests production use ammunitions those wars likely account primary emission sources SCS before 1950, potentially robust indicator historical, regional contamination events.