Lead Isotopes in North American Coals

Abstract

Lead isotopes in North American coals are equally or much more radiogenic than those in the present continental crust (a mean composition for the continental crust is used). It is practicable to distinguish coal and gasoline lead pollutants by examining their isotopic compositions.

Lead isotopes as particulate contaminant tracers and chronostratigraphic markers in lake sediments in northeastern North America

“…The discrepancy between the 14 C date and the date for the UMV peak from the Bermuda coral record (~1850) will be discussed in Section 4. Crawford Lake dips below the isotopic signature of North American coals and reaches isotope ratios resembling Canadian ores, which are typically less radiogenic than North American coal (Chow and Earl, 1972). This suggests that as UMV ore smelting became less important, the new primary source to Crawford Lake in the early 20 th century was ore smelting rather than coal combustion, unlike Siskiwit Lake.…”

“…As is the case for Crawford Lake, the well-known Pb isotope leaded gasoline peak expected for northeastern North America is overwhelmed in Solitaire Lake. (Brown, 1962;Chow and Earl, 1972;Chow et al, 1975;Dickin et al, 1996;Franklin et al, 1983) Pb peak is likely due to coal combustion to the south of Solitaire Lake, as is the case for Crawford Lake.…”

“…It is most likely that this transition is due to increased input due to coal combustion as ore smelting in the UMV region became a less important atmospheric Pb source (Heyl et al, 1959 (Chow and Earl, 1972;Millen et al, 1995). Coal is the most abundant fossil fuel in the world, and by the second half of the 19 th century, its use in North America expanded from steampowered transportation to electricity and steel production (U.S. Department of Energy, 2013).…”

The graphical presentation of lead isotope data for environmental source apportionment

“…Chow & Earl, 1972;Chow, 1975;Bacon et al, 1992;Sugden et al, 1993) and particularly to demonstrate the anthropogenic input from leaded gasoline (e.g. Chow & Johnstone, 1965) and Pb mining activity (e.g.…”

Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

“…Most San Francisco Bay area gasolines and aerosols from 1972 and later have lead isotopic compositions 207 higher in 206 Pbr Pb Ž Rabinowitz and Wetherill, 1972;Hirao and Patterson, 1974;Smith et al, 1992. than those prior to 1972Ž Chow and Johnstone, 1965Chow and Earl, 1972;Rabinowitz and Wetherill, . 1972 .…”