1a. Objectives (from AD-416):
This cooperative study includes characterizing soil and plant factors which affect accumulation of Cd, Pb, and As by crops, including rice, and identifying how to use this technical information in risk assessment for these elements in foods. The goal is to supply information needed for understanding options for growers to comply with food trace element limits under consideration.
1b. Approach (from AD-416):
1) Develop or validate methods of analysis for inorganic As, Cd, and Pb in rice and rice products, and other foods such as lettuce, durum wheat, sunflower kernels, and carrot; 2) Identify soil and plants factors which influence accumulation of these elements in the edible part of crops; and 3) Identify management practices which can reduce levels of As, Cd, and Pb in edible parts of crops.
3. Progress Report:
Research was conducted to assist rice researchers and managers to better understand the joint potential for accumulation of inorganic arsenic (As) and cadmium (Cd) in rice grain with variation of irrigation or soil management to reduce accumulation of As in rice. Also advised other ARS researchers and rice industry on many aspects of rice accumulation of As and Cd. By analysis of samples from existing field trials in Arkansas, showed that growing rice under more aerobic conditions could substantially reduce grain accumulation of As although strong reductions required strong aerobic soil management to obtain. Similarly, growing rice under more aerobic conditions caused significant increase in grain Cd with any increase in aerobic status causing increase in grain Cd. Analyzed rice grain samples from other experiments in cooperation with ARS Rice Research Lab scientists to evaluate production methods effect on grain As, Cd, and other elements. Conducted research to evaluate a new simple method developed at the Eastern Regional Research Center to measure inorganic As in rice grain samples. Purchased equipment and supplies to conduct various methods to evaluate the use of rice with known variations in total and inorganic As. Verified methods for analysis of total As, Cd, zinc, iron, manganese, calcium, and phosphorus in rice grain samples and analyzed over 600 samples from AR experiments.