Pollution records from sediments of three lakes in New York State |
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| Authors: | M Wahlen RC Thompson |
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| Institution: | Division of Laboratories and Research, New York State Department of Health, Albany, NY 12201, U.S.A. |
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| Abstract: | Sediment core segments from Sylvan Lake, Lake Champlain and Lake Canadarago were dated radiometrically with 210Pb and 137Cs. Their respective sedimentation rates were determined to be 0.11, 0.14 and 0.52 g cm?2 yr?1. For the two lakes of lower sedimentation the variations of selected elemental abundances as function of depth were analyzed. Two groupings were found: Al, K, Ti, Rb and Zr were correlated among themselves but reflected different variations in the input of terrigenous erosion material to the lakes. The Cu, Zn and Pb correlated among themselves showed similar depth dependence with increasing concentrations toward the top which can be attributed to cultural pollution. Recent ‘excess’ fluxes to the sediments above the natural contribution by clastic material were derived for the location of the cores, which for Cu, Zn and Pb amounted to 3.8, 24 and 16 μg cm?2 yr?1 respectively for Sylvan Lake and 4.9, 20 and 16 μg cm?2 yr?1 for Lake Champlain. The corresponding 210Pb flux was 3.3 and 2.3 dpm cm?2 yr?1, respectively for the two lakes.Approximate residence times in the water column were obtained for trace metals at the Lake Champlain location. Short residence times estimated for Pb (< 0.15 yr) and Cu (< 0.4 yr) indicate fast removal, whereas those for Zn (1.0 ± 0.3 yr) and Cr (2.0 ± 0.5 yr) appeared to be dominated by the water residence time. |
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