TABLE II

Residency Periods for Chemicals in Ocean

Solution (in years)

Lithium 2.0 x 10^7 Silver 2.1 x 10^6

Beryllium 150 Gadolinium 5.0 x 10^5

Sodium 2.6 x 10^8 Tin 1.0 x 10^5

Magnesium 4.5 x 10^7 Antimony 3.5 x 10^5

Aluminum 100 Cesium 4.0 x 10^4

Silicon 8.0 x 10^3 Barium 8.4 x 10^4

Potassium 1.1 x 10^7 Lanthanum 440

Calcium 8.0 x 10^6 Cerium 80

Scandium 5.6 x 10^3 Praeseodymium 320

Titanium 160 Neodymium 270

Vanadium 1.0 x 10^4 Samarium 180

Chromium 350 Europium 300

Manganese 1400 Gladolinium 260

Iron 140 Dysprosium 460

Cobalt 1.8 x 10^4 Holmium 530

Nickel 1.8 x 10^4 Erbium 690

Copper 5.0 x 10^4 Thulium 1800

Zinc 1.8 x 10^5 Ytterbium 530

Gallium 1.4 x 10^3 Lutetium 450

Germanium 7.0 x 10^3 Tungsten 10^3

Rubidium 2.7 x 10^5 Gold 5.6 x 10^5

Strontium 1.9 x 10^7 Mercury 4.2 x 10^4

Yttrium 7.5 x 10^3 Lead 2.0 x 10^3

Niobium 300 Bismuth 4.5 x 10^4

Molybdenum 5.0 x 10^5 Uranium 5.0 x 10^5

Thorium 350