Vertical profile of PCDD/Fs in soil and sediment around an abandoned e-waste dismantling site

Purpose Informal electronic waste (e-waste) recycling has been identified as a significant source of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), which pose a health and environmental danger. The impact of PCDD/Fs in the e-waste dismantling sites depends on their concentration in environmental matrices. This study aimed to investigate the vertical distribution characteristic of PCDD/F content collected from an abandoned e-waste dismantling site in Guiyu, China, as well as the nearby paddy field and stream. Material and methods One year after the e-waste dismantle site was abandoned, soil, sediment, and mud cores were taken from the site, the neighboring stream, and the paddy field. The source and distribution characteristics of PCDD/Fs in samples were revealed using a variety of statistical analytic methods. Results and discussion The concentrations of PCDD/Fs steadily decreased with increasing soil depth at all sampling sites. The highest concentration of PCDD/Fs was discovered in the sub-layer (10-20 cm) of the e-waste disposal site, at 263,332.72 ng/kg. PCDD/Fs concentrations in soil, sediment, and mud samples were 314.21-16,037.39, 0.01-0.11, and 6.93-97.44 ng I-TEQ/kg, respectively, according to the International Toxicity Equivalency Quantity (I-TEQ). The health risk assessment revealed the harsh working environment for the workers. The association between the three sampling sites was determined using principal component analysis (PCA) and hierarchical cluster analysis (HCA). The main source of PCDD/Fs was e-waste recycling, and one of the explanations for the similarity of PCDD/Fs distribution between the non-plough layer (0-20 cm) of paddy field and sediments was thought to be water management. Conclusion Decades of informal e-waste recycling have led to PCDD/Fs reaching deep into the soil. The order of pollution levels was as follows: e-waste dismantling site > paddy field > stream. The utilization of the e-waste dismantling site and its neighboring lands necessitates meticulous planning and oversight.

Automated summary

Informal e-waste recycling poses a health and environmental danger due to the presence of PCDD/Fs. This study investigated the vertical distribution characteristic of PCDD/Fs in an abandoned e-waste dismantling site in Guiyu, China, as well as the nearby paddy field and stream. The concentrations of PCDD/Fs decreased with increasing soil depth, and the main source was identified as e-waste recycling. The similarity of PCDD/Fs distribution between the non-plough layer of paddy field and sediments was possibly due to water management.