Distribution and Transport of Total Mercury and Methylmercury in Mercury-211 Contaminated Sediments in Reservoirs and Wetlands of the Sudbury River, East-211 Central Massachusetts

摘要

Total mercury and methylmercury were measured in 4 reservoir cores and 12 wetland211u001ecores from Sudbury River. The distribution of total mercury and methylmercury in 211u001ethese cores was evaluated to determine the potential for total mercury and 211u001emethylmercury transport from reservoir and wetlands sediments to the water 211u001ecolumn. Corrected methylmercury concentrations correlated with total mercury 211u001econcentrations in bulk sediment from below the top layers of reservoir and 211u001ewetland cores; methylmercury concentrations at the top layers of cores were 211u001erelatively high, however, and were not correlated with total mercury 211u001econcentrations. Concentrations of methylmercury in pore water were positively 211u001ecorrelated with methylmercury concentrations in the bulk sediment. High 211u001econcentrations of total mercury and methylmercury in sediment (73 and 0.047 211u001emicrograms per gram dry-weight basis, respectively) contributed less to the water 211u001ecolumn in the reservoir than in the wetlands probably because of burial by low 211u001econcentration sediment and differences in the processes available to transport 211u001emercury from the sediments to the water in the reservoirs, as compared to the 211u001ewetlands.