Toxic and Essential Elements in Rice and Other Grains from the United States and Other Countries

Abstract

We determined the concentrations of toxic and essential elements in rice and other grains (lentils, barleys, beans, oats, wheat, and peas) grown in the United States (US) and other countries using Inductively Coupled Plasma Mass Spectrometry (ICPMS). Results showed that median concentrations (in µg/kg) for toxic elements in white rice from the US were 131, 2.8, and 6.5 for arsenic (As), lead (Pb), and cadmium (Cd), respectively. White rice from Thailand, India, and Italy showed higher median toxic elements concentrations (in µg/kg) of 155 for As, 3.6 for Pb, and 8.4 for Cd, than for white rice from the US. Brown rice from the US showed median concentrations (in µg/kg) of 217 (As), 4.5 (Pb), and 17.4 (Cd) while other grains showed median concentrations (in µg/kg) of 5.4, 4.6, and 6.7 for these elements, respectively. None of the samples exceeded the codex standards set for Pb (200 μg/kg in cereals and pulses) and Cd (100 μg/kg in cereals/pulses and 400 μg/kg in polished rice). However, brown rice and one white rice sample did exceed the codex standard for As (200 μg/kg). Essential elements were higher in other grains than in white and brown rice. These findings suggest that alternating or coupling rice with other grains in one’s diet could reduce exposure to toxic metals while providing more essential elements to rice diet.