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【聚焦关键】Mercury in polar environments

2017-11-10 179

时间:2017年11月17日(星期五)15:30-16:30
地点:卫津路校区第16教学楼221报告厅
主讲人:Holger Hintelmann教授,加拿大特伦特大学(Trent University)理学院院长,精于利用新发展的汞同位素技术研究汞的环境地球化学,是高精度甲基汞测试技术以及稳定汞同位素测试技术的早期开发者。发表论文150余篇,总引次数7400余次,h-index=53。

报告摘要:

The polar regions are recognized as being geopolitically and economically important and extremely vulnerable to current and projected climate change. This presentation will summarize the use of glaciers and ice cores as an archive of past accumulation, storage and release of mercury. Long term total Hg and methylmercury records of glacier samples from the Canadian Arctic show that Hg levels increased from < 0.2 ng/L in pre-industrial times to 0.8 - 1.2 ng/L during the last 200 years. Concurrent measurements of Hg isotope ratios suggest that historical variations in the Hg isotope composition recorded in snow and firn on Canadian High Arctic ice caps over the past ~200 years compare remarkably well with those modeled for total atmospheric Hg emissions.
Methylmercury (MMHg) has serious implications for human health, especially for northern Inuit communities, whose diet is predominantly composed of marine fish and mammals. Potential sources of MMHg in the high Arctic were investigated using isotope enriched Hg tracers. We show that methylation of mercury is significant in the polar ocean itself, contributing approximately 50% to the standing pool of the MMHg present in polar marine waters. An alternative source is possibly the formation of dimethylmercury (DMHg) in the ocean. Concentrations of atmospheric MMHg and DMHg were measured during two arctic cruises.