Determination of Heavy Metals Uptake in Soil and Paddy Plants

Fifteen samples each of paddy soil and rice plants were collected from the paddy field area affected by ultrabasic soil contamination in Ranau Valley, Sabah. Soil and rice plantsamples were analyzed for heavy metals i.e: As, Cd, Co, Cr, Cu, Ni and Zn concentrations. The samples were extracted for their total heavy metals content by wet digestion method and then determined using ICP-MS. Results of soil samples indicated high concentrations of Co, Cr, Cu, Ni and Zn but low concentrations of As and Cd. Concentrations of Co, Ni and Cr exceeded the maximum allowable concentration (MAC) and trigger action value (TAV). Biological absorption coefficient (BAC) analysis showed that the rice plants were categorized as non-accumulator of Cr and Ni, low accumulator of As, Co and Cu and moderate accumulator of Cd and Zn. Bioavailability of heavy metals in Ranau Valley paddy fields was low despite the high concentration of heavy metals in the soil.