Enrichment Characteristics and Health Risk Assessment of Heavy Metals in Soil-Crop Systems

The effects of heavy metals in soil-crops systems, their enrichment characteristics, and health risks were investigated by analyzing the As, Cr, Cu, Pb, Cd, and Hg in 216 paired soil and crop samples from Yuyao, Zhejiang Province, China. Statistical analyses, enrichment characteristics, and health risks to adults were assessed using the health risk assessment model used by the U. S. Environmental Protection Agency. The results showed that the main sources of heavy metals were atmospheric pollution, water pollution, and pesticide spraying, that caused local pollution in bayberry soil, and that the Pb pollution source may be industrial waste and oil combustion release. They also indicated that the sources polluting bayberry soil with Cu and Hg were probably the same, the mustard-soil system had a relatively lower absorption capacity for heavy metals, and there was a significant correlation between heavy metals in the soil-rice system. The main carcinogenic risk factors associated with bayberry intake were As and Cr, but there were no non-carcinogenic and carcinogenic risks associated with rice intake. The non-carcinogenic and carcinogenic risks associated with bayberry could be reduced by planting on land not exposed to air and industrial pollution and to avoid spraying bayberry with pesticides.