The Periodic Table of Scarcity and Abundance Cd Cadmium
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Cadmium: How much there is

How much of it exists, and how much of that can we reach?

Cadmium is scarce in the crust, about 0.15 parts per million, but it occurs with zinc. USGS stopped publishing estimates of its reserves in 2015. Supply depends on how much zinc is refined, not on how much cadmium is in the ground.

Last updated 3 October 2026.

In nature

How much of it there is, by mass, on a log scale
Universe 2 ppb 1
Earth's crust 150 ppb 1
Seawater 70 ppt 2
Human body 180 ppb 3

The Earth’s crust holds about 0.15 parts per million of cadmium by mass1. In a 2002 profile, USGS ranks it 63rd among the elements in the crust, about as common as antimony and bismuth4. The universe as a whole holds about 0.002 parts per million1.

The mean for the whole ocean is about 70 nanograms per kilogram of seawater, or 0.00007 parts per million2. The concentration changes steeply with depth. Open-ocean surface water holds less than 5 nanograms per litre3. Plankton take up cadmium at the surface, and it is released at depth when their remains break down3.

A 50-year-old in an area without cadmium pollution carries 5 to 20 milligrams of cadmium in total3. For a body of 70 kilograms, that is about 0.07 to 0.3 parts per million. Food is the main source, and smokers also take it in from tobacco3. Cadmium stays in the kidneys with a biological half-life of 10 to 35 years5.

Cadmium is never found as a native metal, and none of its own minerals is mined alone4. In sphalerite, the main zinc mineral, cadmium often takes the place of zinc6. Wherever zinc ore is mined, the cadmium in it comes out of the ground too.

Reserves and resources

Reserves

500thousand tonnes7

2013. Cadmium content of zinc reserves, as estimated by USGS

The last figure USGS published. From the 2015 edition USGS says quantitative estimates are not available.

Resources

~ 6million tonnes8

2008. Identified resources, from 1.9 billion t of identified zinc resources at about 0.3% cadmium

The last figure USGS published. From the 2010 edition USGS gives no number for world cadmium resources.

USGS estimated world cadmium reserves until its 2014 edition. The last figure was 500,000 tonnes for 20137. Since the 2015 edition, USGS says that quantitative estimates are not available. It gives instead a rule of thumb: typical zinc ores hold about 0.03% cadmium6. World zinc reserves were 240 million tonnes in 20259.

Identified resources were put at about 6 million tonnes, based on 1.9 billion tonnes of identified zinc resources at about 0.3% cadmium. USGS last gave this figure in its 2009 edition8. Coals that contain zinc, in the central United States and elsewhere, also hold cadmium that is not economic to recover8.

Reserves divided by production gave about 23 years in 2013 (500,000 tonnes over 21,800 tonnes)7. A 2002 USGS profile put the ratio at about 30 years for 20004, and the world kept producing. The ratio changes as zinc deposits are found and mined, so it does not count down to a date.

Is it running out?

No. Cadmium supply is set by zinc refining. A refinery recovers anything from none to about 90% of the cadmium in its feed. How much depends on demand for cadmium and on the rules for disposing of cadmium waste4.

The limit on supply comes from demand. Governments, mainly in Western Europe, have cut many uses because cadmium is toxic4. In its 2007 yearbook, USGS warned about laws that cut demand. If they cut it far enough, surplus cadmium might have to be stored for good, as has happened with mercury10.

In 1999 and 2000 the cadmium price was below one third of the zinc price. At that price, USGS said, recovery paid only where it cost less than the disposal of cadmium in smelter wastes4.

A shortage would come from zinc. Cadmium’s exploration and mining costs are part of the costs of zinc4. So the cadmium price can change how much cadmium a refinery recovers, but it has little effect on how much zinc ore is mined.

Sources

  1. 1

    Theodore Gray, periodictable.com (data from Wolfram ElementData), 2026. Technical data for Cadmium (from Wolfram ElementData) , Abundances.

    Abundance in the universe, crust, oceans and human body, as mass fractions.

    • % in Universe 2×10⁻⁷%
    • % in Earth's Crust 0.000015%
    • % in Earth’s Crust 0.000015%
  2. 2

    Monterey Bay Aquarium Research Institute (MBARI), 2026. Periodic Table of Elements in the Ocean: Summary Table , Row 48, Cd.

    Mean ocean concentrations, mostly from Nozaki (1997). Cadmium: 70 ng/kg, 620 pmol/kg.

    • 48 Cd 7.00E+01 112.4100 6.23E-01 620 pmol/kg
  3. 3

    International Programme on Chemical Safety (UNEP, ILO, WHO), 1992. Cadmium (Environmental Health Criteria 134) , Sections 3.1 (oceans) and 6.4 (body burden).

    Open-ocean surface water below 5 ng per litre; total body burden 5 to 20 mg at age 50.

    • the average total body burden of a person of 50 years of age, living in an area not subject to pollution, varies within the range 5-20 mg
    • surface waters of the open oceans give values of … 5 ng/litre
    • absorption of cadmium by phytoplankton in surface waters, its transport to the depths incorporated in biological debris, and its subsequent release
    • the major route of exposure to cadmium for the non-smoking general population is via food … tobacco is an important source of cadmium uptake in smokers
  4. 4

    W.C. Butterman and J. Plachy, U.S. Geological Survey, 2002. Mineral Commodity Profiles: Cadmium (Open-File Report 02-238) , pp. 3-24.

    History, minerals, refining process, uses by period, environment and price history to 2000.

    • similar in abundance to antimony and bismuth and is the 63d element in order of crustal abundance
    • cadmium is never found as a native metal, and only three cadmium minerals are known, none of which is found in sufficient concentration to be mined alone as an ore
    • World reserves would be adequate for about 30 years
    • actual recovery is often dictated by the demand for cadmium and by environmental restrictions on the disposal of cadmium-containing wastes, and ranges from no recovery at all (in some countries) to as much as 90 percent
    • governments, principally in Western Europe have imposed restrictions on the use of cadmium for some purposes
    • zinc producers do not find cadmium extraction to be profitable except insofar as the extraction costs are outweighed by the environmental disposal costs
    • its exploration and mining costs are embedded in those of the two base metals, especially zinc
  5. 5

    World Health Organization, 2019. Exposure to cadmium: a major public health concern .

    Sources of exposure, health effects, WHO guideline values and the IARC classification.

    • its biological half-life in humans is 10-35 years
  6. 6

    U.S. Geological Survey, 2026. Cadmium, in Mineral Commodity Summaries 2026 , pp. 52-53.

    World refinery production, price, US trade, substitutes and events for 2025.

    • often substitutes for zinc in the sphalerite crystal lattice
    • Quantitative estimates of reserves were not available. The cadmium content of typical zinc ores averages about 0.03%
  7. 7

    U.S. Geological Survey, 2014. Cadmium, in Mineral Commodity Summaries 2014 , World Refinery Production and Reserves table.

    Last USGS estimate of cadmium reserves, by country, for 2013.

    • World total (rounded) ... 500,000
    • World total (rounded) … 500,000
    • World total (rounded) … 20,900 21,800
  8. 8

    U.S. Geological Survey, 2009. Cadmium, in Mineral Commodity Summaries 2009 , World Resources.

    Identified world resources of about 6 million t; the last edition that gives a number.

    • estimated world identified resources of cadmium were about 6 million tons, based on identified zinc resources of 1.9 billion tons containing about 0.3% cadmium
    • about 6 million tons
    • Zinc-bearing coals of the central United States and Carboniferous age coals of other countries also contain large subeconomic resources of cadmium
  9. 9

    U.S. Geological Survey, 2026. Zinc, in Mineral Commodity Summaries 2026 , World Mine Production and Reserves table.

    World zinc mine production and reserves, 2025.

    • World total (rounded) … 240,000
  10. 10

    A.C. Tolcin, U.S. Geological Survey, 2010. Cadmium, in 2007 Minerals Yearbook , pp. 15.1-15.3.

    The 2007 price rise, producers by country, Belgium's compound makers and the EU battery directive.

    • a situation could arise, such as has been seen with mercury, where an accumulating oversupply of byproduct cadmium will need to be permanently stockpiled