Trace Elements and Arsenic Speciation of Field and Market Rice Samples in contrasting Agro-climatic Zones in Sri Lanka

Abstract

Rice is a major source for micro-elements for the Sri Lankan population, across all agro-climatic zones. This current study was conducted to investigate the variation of the metal(loid)s and As speciation in rice grains collected from wet, intermediate and dry zones of Sri Lanka. Field rice (brown rice) and market rice (polished rice) samples were analysed for total elemental profile and As speciation using ICP-MS and IC-ICP-MS, respectively. As, Cd, Co, Fe, Mn, Mo, Rb, Se, Sr and Zn in field grain samples varied across climatic zones. Highest median Cd, Cu, Mo, P, Rb, Se and Zn from wet zone; Co, Fe, Mn from intermediate zone; and As and Sr from dry zone were reported. Field rice (As, 0.3%; Cd, 1%) and market rice (As, 0%; Cd, 3%) samples exceeded maximum permissible levels of As and Cd. However, higher concentrations of both fields, 18% samples for As and 21% samples for Cd, and market, 7% samples for As and 38% samples for Cd, rice exceeded the recommended permissible levels of As and Cd in infant food according to EU regulations. The high per capita consumption and the chronic exposure to As and Cd through rice may cause adverse effects on Sri Lankan children and adults.