Implementation strategy: P rock in Fertiliser > Uranium in Fertiliser > Uranium in our Drinking Water

Phosphorous from Phosphate rock contains Uranium

Fertiliser usually contains phosphorus (P), which comes from phosphate rock. However, this phosphate rock also contains Uranium. Simply said: when you mine phosphate rock, you automatically get Uranium as well.

uranium gehalte(mg/kg Source: Schwermetalle in P-Düngemitteln (2003). Presentation by Sylvia Kratz.)


Fertiliser with P in it contains Uranium

Globally 17,8 Megaton of P is used per year in fertiliser. That’s 17.800.000.000 kilogram of P. We’re not talking small dosages here. Even a small country like the Netherlands (the country I live in) annually uses 21.000.000 kg of P per year (as calculated by Stowa).

However, while processing the phosphate rock, the Uranium contents increase. This differs per type of fertiliser. For Super- or Triplephosphate levels can go up to 85-191 mg/kg (for the end product). For 2-compound fertilisers (NP or PK) levels are reached of 89-96 mg/kg and NPK-fertiliser reaches about 14 mg/kg. Sewage sludge has been measured as well, here levels of Uranium are found between 4-32 mg/kg. [1, 2, 3, 4].

Strangely enough, at this point in time there is NO country that has set a legal limit for Uranium levels in fertiliser.

per fertiliser(Source: Schwermetalle in P-Düngemitteln (2003). Presentation by Sylvia Kratz.)

HY Triple Super Phosphate 32275

Uranium levels accumulate in our agricultural land

Scientists of FAL (or these days: Julius Kuhn Institut)  [4] calculated that a phosphorus fertilization rate of 22 kg/ha annually brings about 10-22 g/ha of uranium on our fields. (Actually, for industrial countries 25 kg/ha of P-fertiliser is the average amount).

If you think these amounts aren’t thát high, please keep in mind that fertiliser is continuously used on our land, year, after year, after year. And as Matthew Taylor and Nick Kim have shown in 2007, Uranium accumulates:

accumulation(Accumulation example by Uranium-containing fertiliser in New Zealand. The natural background of U in NZ soils is estimated between 0.6 and 0.8 mg/kg.)


Contamination of ground leads to contamination of our tap water

Through the usage of fertilizers, the background contamination of Uranium in our tap water accumulates. However, there is no country that has set a legal limit for uranium in drinking water, but Germany (since 2011).


(Uranium in drinking water samples, research by Ewald Schnug & Manfred Birke in 2007 – look at the ‘median’ figures, they are in µg/l)

For Europe the Federal Institute for Risk Assessment of Germany (BfR) has initiated a  limit of 0.01 mg/l (10 µg/l), which has been adopted by the German government in november 2011.

Unfortunately, for babies and small children this legal level still seems to be too high. Foodwatch advises to limit the amount of Uranium to 0.002 mg/l (2 µg/l).


“Oh, but we’re all about organic farming!”
Forget about it.

Crushed rock phosphate is currently permitted as a fertilizer in organic agriculture in at least the European Union (EU, 2007), India (Department of Commerce, 2005) and Australia (Organic Federation of Australia, 2005).


What do we need to do next?

  1. Politics: set a legal limit for Uranium in fertiliser NOW.
  2. Politics: set a legal limit for Uranium in drinking water NOW.
  3. Politics: Set a clearly defined goal (f.e. 2020) to eliminate uranium from fertilizer streams.
  4. Industry: Measurably define your fertilizer inputs.
  5. Industry: Measurably define the uranium content of your fertiliser products.
  6. Industry: Make a plan to phase out usage of P rock, and implement recycled P.


Non-online sources:

[1] Krat z, S. and Schnug, E. (2005): Rock phosphates and P fertilizers as sources of U contamination in agricultural soils. Institute of Plant Nutrition and Soil Science, Federal Agricultural Research Center (Bundesforschungsanstalt für Landwirtschaft [FAL]), p. 1-11, Germany

[2] Saueia, C.H., Mazzilli, B.P., Fa´ varo, D.I.T. (2005). Natural radioactivity in phosphate rock, phosphogypsum and phosphate fertilizers in Brazil. Journal of Radioanalytical and Nuclear Chemistry 264, 445–448.

[3] Kratz, S., Schnug, E. (2006). Rock Phosphates and P Fertilizers as Sources of U Contamination in Agricultural Soils. Institute of Plant Nutrition and Soil Science, Federal Agricultural Research Center, Germany, pp. 57–67; in Uranium in the Environment: Mining Impact and Consequences, Springer Berlin Heidelberg.

[4] Bundesforschungsanstalt für Landwirtschaft (FAL), Institut für Pflanzenernährung und Bodenkunde (2007). Phosphatdünger können große Mengen an Uran enthalten. These days FAL is part of the Julius Kuhn Institut.


Additional reading:



This text is for a large part based on information I’ve received from scientists working at EPEA. There’s many people in this company that have added to the change we need to make in society that we like to call “keeping P in cycles”, but I want to give some special attention to my (former) team members Mark Siegenbeek van Heukelom, Wolfgang Schönknecht, Oliver Lojek (who collected most of the articles that you can now find here), Tanja Scheelhaase, Julia Model, and Sanne van den Dungen. Special thanx also goes to Douglas Mulhall & Katja Hansen who have put years of their professional life into bringing attention to and finding solutions for this specific topic. And, of course, my deepest respect goes out to prof. dr. Michael Braungart, as he opened my eyes to the urgency of the P-topic.

Tip for Dutch partners:
Based on the conversations I’ve had with them about this topic I highly recommend you to contact Willem Schippers (former Thermphos) and/or Leon Korving (former SNB, now Wetsus).

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