Table I.
Isotopic compositions and concentrations of lead in San Francisco Bay waters from 1989 to 1998
| Station | Unfiltered lead concentration (μg/kg) | Filtered lead concentration (μg/kg) | 206Pb/ 204Pb | 206Pb/ 207Pb | 208Pb/ 207Pb |
|---|---|---|---|---|---|
| December 1989 | |||||
| BA20 | 3.28 | 0.0370 | 18.415 | 1.1830 | 2.4488 |
| BA30 | 2.40 | 0.0360 | 18.445 | 1.1833 | 2.4482 |
| BA40 | 1.07 | 0.0259 | 18.428 | 1.1845 | 2.4484 |
| BA40 | 1.07 | 0.0259 | 18.440 | 1.1852 | 2.4486 |
| BC10 | 0.44 | 0.0174 | 18.486 | 1.1840 | 2.4521 |
| BC11 | 0.83 | 0.0111 | 18.471 | 1.1842 | 2.4501 |
| BD31 | 1.48 | 0.0169 | 18.491 | 1.1859 | 2.4513 |
| BF35 | 0.58 | 0.0244 | 18.466 | 1.1867 | 2.4493 |
| BG20 | 0.73 | 0.0362 | 18.375 | 1.1837 | 2.4443 |
| April 1992 | |||||
| BA30 | 0.60 | 0.0342 | 18.432 | 1.1857 | 2.4471 |
| BA40 | 0.30 | 0.0302 | 18.421 | 1.1851 | 2.4468 |
| BC10 | 0.10 | 0.0192 | 18.418 | 1.1814 | 2.4473 |
| BC40 | 0.10 | 0.0152 | 18.353 | 1.1810 | 2.4449 |
| BF10 | 1.30 | 0.0108 | 18.451 | 1.1870 | 2.4506 |
| BG10 | 1.00 | 0.0409 | 18.568 | 1.1925 | 2.4546 |
| BG20 | 0.90 | 0.0162 | 18.533 | 1.1932 | 2.4537 |
| March 1993 | |||||
| BA20 | 0.62 | 0.0874 | 18.571 | 1.1925 | 2.4509 |
| BA40 | 0.33 | 0.0275 | 18.473 | 1.1854 | 2.4484 |
| BC40 | 0.47 | 0.0132 | 18.427 | 1.1857 | 2.4486 |
| BD20 | 0.33 | 0.0213 | 18.563 | 1.1937 | 2.4546 |
| BF10 | 2.34 | 0.2120 | 18.731 | 1.2029 | 2.4618 |
| BG20 | 0.92 | 0.0409 | 18.739 | 1.2034 | 2.4619 |
| BG30 | 0.91 | 0.2890 | 18.722 | 1.2020 | 2.4608 |
| September 1993 | |||||
| BA20 | 0.41 | 0.0247 | 18.461 | 1.1852 | 2.4499 |
| BA40 | 0.45 | 0.0059 | 18.370 | 1.1833 | 2.4453 |
| BC41 | 0.89 | 0.0106 | 18.432 | 1.1816 | 2.4487 |
| BD20 | 0.27 | 0.0123 | 18.460 | 1.1867 | 2.4501 |
| BF10 | 1.17 | 0.0088 | 18.482 | 1.1887 | 2.4521 |
| BG20 | 0.69 | 0.0662 | 18.697 | 1.1953 | 2.4611 |
| BG30 | 1.07 | 0.0476 | 18.556 | 1.1909 | 2.4538 |
| February 1995 | |||||
| BA20 | 0.39 | 0.0884 | 18.526 | 1.1896 | 2.4484 |
| BA40 | 0.35 | 0.0287 | 18.441 | 1.1860 | 2.4471 |
| BC41 | 0.17 | 0.0178 | 18.500 | 1.1914 | 2.4521 |
| BD20 | 0.35 | 0.0022 | 18.644 | 1.1984 | 2.4583 |
| BF10 | 1.01 | 0.0095 | 18.663 | 1.1993 | 2.4592 |
| BG20 | 0.62 | 0.0753 | 18.738 | 1.2049 | 2.4621 |
| BG20 | 0.62 | 0.0753 | 18.739 | 1.2045 | 2.4622 |
| BG30 | 0.54 | 0.0109 | 18.687 | 1.2017 | 2.4597 |
| August 1995 | |||||
| BA30 | 2.12 | 0.0463 | 18.453 | 1.1865 | 2.4479 |
| BA40 | 0.75 | 0.0211 | 18.442 | 1.1856 | 2.4475 |
| BC41 | 0.18 | 0.0100 | 18.416 | 1.1843 | 2.4473 |
| BD20 | 0.60 | 0.0079 | 18.541 | 1.1869 | 2.4560 |
| BF10 | 0.53 | 0.0056 | 18.562 | 1.1921 | 2.4547 |
| BG20 | 0.50 | 0.0054 | — | 1.1971 | 2.4667 |
| BG30 | 0.63 | 0.0115 | — | 1.1896 | 2.4561 |
| July 1998 | |||||
| BG20 | 0.50 | 0.1130 | 18.740 | 1.1992 | 2.4654 |
| BG30 | 0.32 | 0.0990 | 18.754 | 1.1996 | 2.4658 |