Accumulation of sediments, trace metals (Pb, Cu) and total hydrocarbons in Narragansett Bay, Rhode Island

摘要: Abstract The accumulation of sediments, trace metals and hydrocarbons has been estimated from the analysis sediment six coring sites in Narragansett Bay. Radionuclides ( 234 Th xs , 210 Pb 239,240 Pu) with known input functions (Cu, Pb) were used. We estimate that 6·9 × 10 4 tons 51–90 Pb, 72–100 Cu 400–1000 total accumulate annually under present conditions bay. This represents 64–117% (Pb), 89–123% (Cu) 23–58% (hydrocarbons), respectively, day inputs to Furthermore, close 100% particle-reactive radionuclides Pu Present bay calculated independently as 77–80 81 Cu. Sewage effluents dominant source Cu, whereas atmospheric deposition urban runoff most important for Pb. Dredging activities by U.S. Army Corps Engineers between 1946 1971 removed more sediments than would have accumulated during same time undredged areas Copper smelting coal mining on shores upper 1866–1880 left an imprint which is still evident. Model derived rates 3–4 times present-day inputs.