Project Number: 1265-12000-037-10
Project Type: Reimbursable

Start Date: Sep 15, 2003
End Date: Mar 30, 2008

Objective:
Summarize literature on potential risk to consumers of cadmium applied to land as part of phosphate fertilizers. Includes availability to plants over time, transfer to edible plant parts over time, and bioavailability to animals of Cd in crops grown on fertilized soils, and the exclusion of cadmium from livestock products. Consider wide literature on cadmium in the agricultural environment, and nature of phosphate products in the marketplace. Characterize levels of Cd or Cd:Zn which provide protection against adverse effects of cadmium in fertilizers. Interpret information in relation to proposed limits on cadmium in fertilizer products in the EU to support needs of The Fertilizer Institute.

Approach:
Conduct literature review to identify appropriate and inappropriate methods to assess potential food-chain transfer and risk from cadmium in phosphate fertilizer products. Studies which tested cadmium salts are likely to over-predict risk because phosphate reactions with iron in soils increases specific adsorption of cadmium, and zinc which accompanies cadmium in phosphate fertilizers can inhibit cadmium uptake and bioavailability. Interpret potential risks from cadmium in phosphates with respect to new paradigm for cadmium risk due to zinc, iron and calcium deficiency in subsistence rice consumers. Contrast soil cadmium potential risks from different cadmium sources including fertilizers, cadmium aerosol emissions, manures, biosolids, limestone, etc. Evaluate proposed scientific basis for EU limits on cadmium in phosphates and the database for the draft regulations. Summarize information which could improve the EU risk assessment.