Regional Lead Isotope Study of a Polluted River Catchment
1 Regional lead isotope study of a polluted river 2 catchment: River Wear, Northern England, UK 3 4 Thomas J. Shepherd a*, Simon R.N.Chenery b, Vanessa Pashley c, Richard 5 A. Lord d, Louise E. Ander b, Neil Breward b, Susan F. Hobbs b, Matthew 6 Horstwood c, Benjamin A. Klinck b, Fred Worralla 7 8 a Department of Earth Sciences, University of Durham, Science Laboratories, Durham DH1 3LE, UK 9 b British Geological Survey, Nicker Hill, Keyworth, Nottingham NG12 5GG, UK 10 c NERC Isotope Geosciences Laboratory, Kingsley Dunham Centre, Keyworth, Nottingham NG12 11 5GG, UK 12 d School of Science and Technology, University of Teesside, Middlesbrough, Tees Valley TS1 3BA, UK 13 _________________________________________________________ 14 Abstract 15 16 High precision, lead isotope analyses of archived stream sediments from the River Wear catchment, 17 northeast England (1986-88), provide evidence for three main sources of anthropogenic lead pollution; 18 lead mining, industrial lead emissions and leaded petrol. In the upper catchment, pollution is totally 19 controlled and dominated by large lead discharges from historic mining centres in the North Pennine 20 Orefield (208Pb/206Pb, 207Pb/206Pb ratios range from 2.0744 - 2.0954 and 0.8413 - 0.8554 respectively). 21 In the lower catchment, co-extensive with the Durham Coalfield and areas of high population density, 22 pollution levels are lower and regionally more uniform. Isotope ratios are systematically higher than in 23 the upper catchment (208Pb/206Pb, 207Pb/206Pb ratios range from 2.0856 -2.1397 and 0.8554 - 0.8896 24 respectively) and far exceed values determined for the geogenic regional background.
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