Contamination and risk of heavy metals in soils and sediments from a typical plastic waste recycling area in North China

• Surface soils and sediments have suffered from moderate to high metal pollution.
• High Cd and Hg pollution presented in both soils and sediments.
• The non-carcinogenic risk from soil metals to local children is unacceptable.
• Crude plastic waste recycling is a significant metal source to the environment.

Plastic wastes are increasingly being recycled in many countries. However, available information on the metals released into the environment during recycling processes is rare. In this study, the contamination features and risks of eight heavy metals in soils and sediments were investigated in Wen'an, a typical plastic recycling area in North China. The surface soils and sediments have suffered from moderate to high metal pollution and in particular, high Cd and Hg pollution. The mean concentrations of Cd and Hg were 0.355 and 0.408 mg kg−1, respectively, in the soils and 1.53 and 2.10 mg kg−1, respectively, in the sediments. The findings suggested that there is considerable to high potential ecological risks in more than half of the soils and high potential ecological risk in almost all sediments. Although the health risk levels from exposure to soil metals were acceptable for adults, the non-carcinogenic risks to local children exceeded the acceptable level. Source assessment indicated that heavy metals in soils and sediments were mainly derived from inputs from poorly controlled plastic waste recycling operations in this area. The results suggested that the risks associated with heavy metal pollution from plastic waste recycling should be of great concern.