Pollution, Risk and Transfer of Heavy Metals in Soil and Rice: A Case Study in a Typical Industrialized Region in South China

Abstract

Rice paddies in industrialized areas are particularly impacted by heavy metal contaminations. Based on 205 pairs of soil and rice samples collected from Yingtan, a typical industrialized region in southern China, the work was carried out to investigate the characteristics of heavy metals in soils and rice, evaluate their corresponding health risks to local residents and elucidate the migration and enrichment patterns of the trace elements from soil to rice. Approximately 98.5%, 77.6% and 70.2% of the soil samples were polluted by Cd, Pb and Cu, while 34.6%, 23.4% and 15.6% of the rice grain samples had contents of Cd, As and Pb exceeding the standard limitations, respectively. Consuming locally produced rice posed serious risks to local residents. The non-carcinogenic risks were primarily due to dietary intake of i-As and Cd, and carcinogenic risks were mainly caused by i-As in rice grains. Cd is most likely to be migrated and enriched. The bioaccumulation process is influenced by a combination of environmental factors, such as soil pH, TOC, heavy metal contents in bioavailable fractions and mineral elements, such as Al, Mn and Fe. The findings help in making effective pollution prevention and control regulations for guaranteeing the health of local residents.