Total As and As Speciation in Italian Rice as Related to Producing Areas and Paddy Soils Properties

Rice and rice-based foodstuffs are important pathways for inorganic As dietary intake. This work shows a detailed picture of As content and speciation in Italian rice, which contributes to more than one-half of the European production, and addresses the role of soil chemistry and agronomic management on As concentration in rice grain, in view of ameliorative strategies. The mean total As content in Italian white rice was 155 ± 65 μg kg-1 with significant differences among producing areas, while the mean inorganic As was 102 ± 26 μg kg-1, largely below the E.U. limit of 200 μg kg-1 for white rice, although part of the production would not be suitable for baby food production, which requires less than 100 μg kg-1 of inorganic As. The differences in As content and speciation in rice among the studied areas resulted from the complex interactions of soil, plant, and anthropic factors. Among others, Si nutrition seemed to play a key role in regulating As transfer from soil to plant.