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

Historical trends of metals in the sediments of San Francisco Bay, California

“…After 1952, Ai concentrations are greater than would be expectec from the Ag/Pb relationship in sediments depositec when the Pb smelter was most influential in S a Pablo Bay ( Fig. 8; see also Ritson et al, 1999). Tht relatively recent maxima in Ag concentrations in thc Central and Richardson Bay sediments thus ma!…”

“…Thus, the high sedimentation rates in North San Francisco Bay may have diluted substantial local Pb inputs. The isotopic signature of Pb in SP90-8, clearly shows a signal consistent with large inputs from the Selby Pb smelter (Ritson et al, 1999). Documented Pb releases from the smelter were --16 T/yr of Pb between 1900 and 1970 (Rabinowitz and Wetherill, 1972), compared to Pb releases of 18 T/yr from the 50 known industrial and municipal discharges in 1990 (Gunther et al, 1987).…”

“…Documented Pb releases from the smelter were --16 T/yr of Pb between 1900 and 1970 (Rabinowitz and Wetherill, 1972), compared to Pb releases of 18 T/yr from the 50 known industrial and municipal discharges in 1990 (Gunther et al, 1987). Isotope signatures also suggest the effects of the smelter could have been highly influential over a broad area of San Francisco Bay (Ritson et al, 1999). Widespread recovery from Pb contamination is reported in sediments from systems dominated by atmospheric inputs (Smith and Flegal, 1995;Callendar and Van Metre, 1997).…”

Heavy metal and Pb isotopic compositions of aquatic organisms in the Pearl River Estuary, South China

“…Stable Pb isotopic studies have been commonly applied to assess the sources of Pb in various ecosystems, including sediments (Farmer et al, 1996;Ritson et al, 1999;Liu et al, 2003), soils (Sugden et al, 1993;Semlali et al, 2001;Wong et al, 2002), suspended matters (Hinrichs et al, 2002), and atmospheric depositions Rosman, 2000 andWong et al, 2003). However, only a few studies have focused on stable Pb isotopes in biological samples to trace the anthropogenic origins of Pb (Kurkjian and Flegal, 2003).…”

The use of Pb isotope ratios determined by magnetic sector ICP-MS for tracing Pb pollution in marine sediments near Casey Station, East Antarctica

“…Pb isotope ratios with 204 Pb as the ratio basis (e.g., 208 Pb/ 204 Pb, 206 Pb/ 204 Pb) are often presented for studies with a geological bias or focus, 18,[21][22][23][24][25] while for many environmental applications, ratios based on the 206 Pb and 207 Pb pair are more often reported. 13,[26][27][28][29] This difference can be attributed to: (i) The need for geologists to determine very accurate ratios of radiogenic to non-radiogenic lead which, in turn, can be related to geological process and age.…”