Accumulation of heavy metals in different parts of wheat plant from the Yangtze River Delta, China

Abstract

With the rapid economic development and increased human activities, the soil heavy metal pollution has become a serious environmental problem in the world. This study investigated the heavy metal accumulation in soil and bioaccumulation in wheat in the Yangtze River Delta, particularly in Suzhou-Kunshan, to provide theoretical guidance for economic development and pollution control. Wheat plants were collected and divided into four parts: root, stem, leaf, and grain. The concentrations of eight heavy metals (Hg, As, Cr, Cu, Ni, Pb, Zn and Cd, As is a metalloid) in each wheat plant part were evaluated, and the accumulation and relationship of these heavy metals (HMs) were analyzed. Results indicated that the roots had the greatest accumulating capability among the four plant parts, also the roots are the main channel of heavy metal accumulation in wheat plant. The most and least accumulated HMs were Cd and Cr, respectively. Correlation analysis revealed a relationship between heavy metal concentration in the grains and other plant parts of wheat. However, no consistent pattern was found. This result could be attributed in part to the atmosphere-derived HMs in wheat; thus, outer contaminants and reactions might exist in the plants.