Elemental Composition of Rice and Lentils from Various Countries: A Probabilistic Risk Assessment of Multiple Life Stages

Cereals such as rice and lentils can accumulate toxic elements including arsenic (As), cadmium (Cd), and lead (Pb), which could lead to adverse health effects through diet. Cereals simultaneously contain essential elements including Magnesium (Mg), Calcium (Ca), Iron (Fe), Zinc (Zn), and Selenium (Se), which are vital for human health. We purchased a total of 63 rice and 19 lentils samples from retail stores and determined elemental composition using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Our results showed mean concentrations (in µg/kg) of 177 ± 79, 16 ± 18 and 24 ± 42 in brown rice, 117 ± 76, 49 ± 27, and 4 ± 4 for wild rice, 172 ± 65, 14 ± 14, and 10.4 ± 11 for black rice and 144 ± 53, 21 ± 24, and 22 ± 42 in white rice for As, Cd, and Pb, respectively. Lentils had mean concentrations of 8.5 ± 4.5, 2.8 ± 3.4, and 24 ± 40 in similar elements, respectively. Mean concentrations (in mg/kg) of Mg, Ca, Fe, Zn, and Se were 797 ± 370, 207 ± 220, 25 ± 25, 24 ± 13 and 0.199 ± 0.330, respectively in all samples. However, lentils had higher concentrations of essential elements as compared to rice. Pollution index calculations indicated a level of pollution greater than 1 in brown rice. Median lifetime cancer risks were above the acceptable level for age groups 6 to < 12 months to 11 < 16 years in all rice samples except brown rice. Data in this study highlights the health risks associated with dietary exposure to toxic metals in cereals and the nutritional components in these food groups.