Lagging pollution of polycyclic aromatic hydrocarbons in the rebuilt e-waste site: From the perspective of characteristics, sources, and risk assessment

Little information is known regarding how the lagged pollution of polycyclic aromatic hydrocarbon (PAH) influenced the environment and human health after an e-waste dismantling site was rebuilt. This study investigated the characteristics, sources, and risk assessment of PAHs in a rebuilt e-waste site and its surrounding farmland by analyzing the samples of soil, dust, water, and vegetable. Concentrations of PAHs in soil, vegetable and water in the rebuilt site were relatively higher than in its surrounding farmland. The concentrations in surface soils, soil columns, dust, vegetables, and water varied from 55.4 to 3990 ng g- 1, 1.65 to 5060 ng g- 1, 2190 to 2420 ng g-1, 2670 to 10,300 ng g-1, and 46.8 to 110 mu g L-1 in the e-waste site, respectively. On the farmland, PAH concentrations in surface soils, vegetables, and water ranged from 41.5 to 2760 ng g- 1, 506 to 7640 ng g-1, and 56.6 to 89.2 mu g L-1, respectively. A higher proportion of high-molecular-weight PAHs (HMWPAHs) appeared in all multimedia compared with low-molecular-weight PAHs (LMW-PAHs). Diagnostic ratio together with positive matrix factorization (PMF) revealed that vehicle emission was the primary source in this area, and the activity of e-waste disposal was another important source in the rebuilt e-waste site. Based on the deterministic health risks, people working in the reconstructed e-waste site were exposed to low risks, whereas the residents living near the surrounding farmland were exposed to low risk. Sensitivity analyses indicated that exposure frequency and PAH concentrations were the main factors that influenced exposure risk. This study provides valuable insight into the comprehension of the lagging pollution effects of PAH on the environment and human health after the e-waste site was rebuilt.