“Fertilizers are indispensable for ensuring [agricultural] sustainability...nitrogen, sulfur, and potassium fertilizers are relatively free of impurities, but phosphorus (P) fertilizers...contain several contaminants...” states an article, dated 2008, titled, “Pasture Soils Contaminated with Fertilizer-Derived Cadmium and Fluorine: Livestock Effects" (Reviews of Environmental Contamination and Toxicology, v. 192).
The article is about a fertilizer study by the Fertilizer and Lime Research Center, Institute of Natural Resources, Massey University, Palmerston North, New Zealand. The authors are Loganathan P, Hedley MJ, and Grace ND.
Fertilizers & Food Safety
According to the fertilizer study phosphorus fertilizers are used mainly for commercial bean and pea pasture production. The two contaminants from phosphorus fertilizers of most concern, according to the study, are cadmium (Cd) and fluorine (F).
According to the Farlex Medical Dictionary online Cd is poisonous, and can cause “violent gastrointestinal symptoms.” The Farlex Medical Dictionary states that F in “excessive amounts” is corrosive, toxic, and can “mottle tooth enamel and cause osteosclerosis [bone and bone marrow hardening]."
The Massey University fertilizer study expresses concern about fluorine and cadmium stating “...they have potentially harmful effects on soil quality, livestock health, and food safety.” The study article states that the majority of Cd and F in pastures accumulates in topsoil.
Groundwater Pollution From Phosphorus Fertilizers
Fluorine and cadmium could pose a shallow groundwater risk, according to the Massey University article. Cadmium contamination in “very acidic soils containing low organic matter” can pollute shallow groundwater. Fluorine contamination in “very acidic low-P fixing soils” can pollute shallow groundwater. The article states that there is insufficient research to determine the effects of permanent low levels of Cd and F on “soil microbial activity.”
Causes of Water Pollution
Groundwater or surface water can be polluted by “point-source or non-point-source pollution,” according to an (author unknown) article, dated 3/10/2009, titled “Fertilizer/Pesticide Contamination.” The article is by the U.S. Environmental Protection Agency (EPA), and published on their web site. Pollution of water from a point source occurs where the fertilizer and pesticide, or other types of land pollution, exists in soil. Non point source pollution is caused “...such as the movement of fertilizers into streams...runoff.”
The EPA article states that fertilizers and pesticides can travel through water systems or leach straight down from the soil surface. The EPA says about non point source pollution “...pesticides and fertilizers can be carried great distances off-site.”
The Massey University fertilizer study concludes that additional study is needed to find solutions to phosphorous fertilizer soil contamination. The study recommends computer models be developed to assess farms at high risk for cadmium and fluorine pollution from fertilizer. The EPA article states that fertilizer and pesticide contamination can leach down to groundwater, or be carried by ditches, streams, and other water systems, to pollute land at remote areas from the source.
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