Lead in rice: Analysis of baseline lead levels in market and field collected rice grains

• DOI: 10.1016/j.scitotenv.2014.03.090
• Publication Date: 2014-04-16T00:45:43Z
• Authors: Gareth J. Norton; Paul N. Williams; Eureka E. Adomako; Adam H. Price; Yongguan Zhu; Fang-Jie Zhao; Steve McGrath; Claire M. Deacon; Antia Villada; Alessia Sommella; Ying Lu; Lei Ming; P. Mangala C.S. D...; Hugh Brammer; Tapash Dasgupta; M. Rafiqul Islam; Andrew A. Meharg
• Keywords: 2. Zero hunger; 0301 basic medicine; Market survey; Data Collection; Food Contamination; Oryza; 630; SOILS; TRANSLOCATION; CULTIVARS; SOUTHEAST CHINA; CADMIUM; 03 medical and health sciences; HEAVY-METALS; Lead; PADDY RICE; Soil Pollutants; Rice; Genetic variation; HEALTH; CROPS; Risk assessment; ACCUMULATION

In a large scale survey of rice grains from markets (13 countries) and fields (6 countries), a total of 1578 rice grain samples were analysed for lead. From the market collected samples, only 0.6% of the samples exceeded the Chinese and EU limit of 0.2 μg g(-1) lead in rice (when excluding samples collected from known contaminated/mine impacted regions). When evaluating the rice grain samples against the Food and Drug Administration's (FDA) provisional total tolerable intake (PTTI) values for children and pregnant women, it was found that only people consuming large quantities of rice were at risk of exceeding the PTTI from rice alone. Furthermore, 6 field experiments were conducted to evaluate the proportion of the variation in lead concentration in rice grains due to genetics. A total of 4 of the 6 field experiments had significant differences between genotypes, but when the genotypes common across all six field sites were assessed, only 4% of the variation was explained by genotype, with 9.5% and 11% of the variation explained by the environment and genotype by environment interaction respectively. Further work is needed to identify the sources of lead contamination in rice, with detailed information obtained on the locations and environments where the rice is sampled, so that specific risk assessments can be performed.