Geology Commons^™

Past Leaded Gasoline Emissions As A Nonpoint Source Tracer In Riparian Systems: A Study Of River Inputs To San Francisco Bay, Charles E. Dunlap, Robin Bouse, A. Russell Flegal

Charles Dunlap

Variations in the isotopic composition of lead in 1995- 1998 river waters flowing into San Francisco Bay trace the washout of lead deposited in the drainage basin from leaded gasoline combustion. At the confluence of the Sacramento and San Joaquin rivers where they enter the Bay, the isotopic compositions of lead in the waters define a linear trend away from the measured historical compositions of leaded gas in California. The river waters are shifted away from leaded gasoline values and toward an isotopic composition similar to Sierra Nevadan inputs which became the predominant source of sedimentation in San Francisco Bay …