Sources and Sinks of Pb, Cu, Zn, and Mn in the Main Basin of Puget Sound

摘要

Municipal, industrial and atmospheric sources contributed 66% of the total Pb added to the main basin of Puget Sound. Advective inputs were the major sources of total Cu and Zn (approximately 40%) while riverine and erosional sources contributed about 30%. The discharge of the particle-bound trace metals from rivers minimized the impacts of particulate anthropogenic sources, which constituted 50%, 23% and 18% of the total particulate Pb, Cu and Zn inputs, respectively. While advective transport was the major source of dissolved Cu and Zn (approximately 60% of all dissolved inputs), industrial, municipal and atmospheric inputs contributed 85%, 30% and 38% of the dissolved Pb, Cu and Zn inputs, respectively. Diffusion of dissolved Mn was the major source of Mn to the main basin. About 75% of the dissolved Pb discharged into the main basin of Puget Sound was lost from the dissolved phase and was balanced by a similar gain in the particulate phase. Because of the effective retention of particles within the main basin, extensive scavenging resulted in about 70% of the total Pb added to the main basin being retained in the underlying sediments.