Elemental Contaminants in Fertilizers and Soil Amendments Used in Organic Production

Summary

Elemental contaminants in fertilizers pose a threat to human health and the environment. Organic agriculture can take measures to protect the public and the environment from the long-term effects of these contaminants, also known as heavy metals. Arsenic (As), cadmium (Cd), and lead (Pb) were identified as the top priority metals that need attention. Fertilizers and soil amendments used in organic production were randomly selected, and the laboratory results for the levels of As, Cd, and Pb compared against six different standards based on different models. Organic farmers are advised to avoid using fertilizers that may degrade the average levels found in soils in the United States. Standard-setting bodies are advised to prohibit the use of fertilizers and soil amendments that have As, Cd, and Pb that will result in the accumulation of those elements in the soil when applied at average loading rates on an annual basis.