Mercury and other trace elements in coal in the lower mackenzie basin, Canada

摘要

The Mackenzie River has recently been shown to be the largest known source of mercury (Hg) to the Beaufort Sea of the Arctic Ocean where very high levels of Hg have been observed in marine mammals. As the lower Mackenzie Basin is a major reserve of fossil fuel in Canada and due to the strong affinity of Hg to reduced sulphur, we hypothesize that certain areas of the Lower Mackenzie Basin may be geologically enriched in Hg, which may have contributed to the mercury budget in the Beaufort Sea. To test this hypothesis, coal samples were collected from the Mackenzie basin and analyzed for Hg and other trace elements. Preliminary results show that Fig levels range from 0. 05 to 2. 4mg/kg. Although the lower end of the range is comparable to world av erages (0.01 to 0. 15mg/kg), some highly Hg-enriched coal samples have been detected in the Mackenzie Basin. Concentrations of other trace elements ranged from 3680 to 20290mg/kg for Fe, 0. 8 to 33. 7mg/kg for Pb, 1.2 to 285mg/kg for Ni, 0. 02 to 8. 2mg/kg for Cd, 0. 9 to 276mg/kg for V, 0. 8 to 120mg/kg for As, <0. 1 to 825mg/kg for Zn, amongst many others.