Health implication of heavy metals exposure via multiple pathways for residents living near a former e-waste recycling area in China: A comparative study

摘要

Herein, crop (vegetables and rice, n = 30), soil (n = 14), dust (n = 12), and PM10 (n = 25) samples were collected to assess the environmental quality of a former e-waste recycling area and evaluate the related health risks. In dust and PM10, the concentrations of heavy metals (Cd, Cu, Ni, Pb, and Zn) were lower than previously reported values, although the numbers for soil, vegetables, and rice remained high. The average accumulation factors of heavy metals in crops decreased in the order of Zn Cd Ni Cu Pb, and soil was identified as the largest contributor to crop pollution. Heavy metal ingestion largely occurred via rice consumption, which accounted for a significant fraction of the total average daily dose (ADD; 75.2-86.7% in children and 78.0-91.7% in adults), especially for Cd, Cu, Ni, and Zn. However, in the case of Pb, soil ingestion accounted for 48.9% of the ADD in adults, while in children, vegetable, rice, and dust ingestion accounted for 44.7%, 28.6%, and 23.7% of the ADD, respectively. The combined exposure hazard indices at the fifth, median, and 95th percentiles for all heavy metals were determined as 2.54, 9.40, and 40.1 for adults and as 3.75, 13.7, and 58.4 for children, respectively. In terms of health risk, crop consumption was identified as the major exposure pathway for both children and adults, featuring a contribution of 99.9%. In addition, the 95th percentile carcinogenic risks for Pb exceeded the acceptable level. Thus, this work shows that to reduce the health risk for local residents in the former e-waste area, more attention should be paid to soil repair.