Bioaccessibility and provenance of heavy metals in the park dust in a coastal city of southeast China

摘要

Bioaccessibility and provenance of heavy metals (V, Cr, Co, Ni, Cu, Zn, As, Cd, Ba, Pb) in the park dusts were investigated. The enrichment factors (EFs) indicated that Cd, Cu, and Zn were substantially higher enriched than the other heavy metals. An in vitro test of Solubility Bioaccessibility Research Consortium method (SBRC) and a modified sequential extraction method recommended by the European Community Bureau of Reference (BCR) were used to determine heavy metals bioaccessibility. The average bioaccessibility index (K) of most heavy metals was above 0.2, excluding Ba and Cr. In particular, extremely high bioaccessibilities of Zn (K = 0.83), Cd (K = 0.74), Pb (K = 0.62), and Cu (K = 0.59) were observed in the park dusts. Based on the Pb isotope technique, coal dust, soil parent materials and fertilizers, and traffic sources were accounting for 58%, 35%, and 7% of Pb in the park dust, respectively. The principle component analysis and multiple linear regression (PCA-MLR) results of the additive log-ratio transformation (coal combustion: 56.6%; soil parent materials and fertilizers: 36.8%; traffic sources: 6.6%) were more in good agreement with the Pb isotope technique results. Compared with the original data and the direct logarithmic transformation, the contributions were all positive values in the results of the additive log-ratio transformation, suggesting an effective method to open geochemical component data. Thus, the additive log-ratio transformation has strong interpretability in source appointment as well as better dimension reduction. This study provides an example to explore bioaccessibility in view of binding state and identify sources of multiple heavy metals in the park dust using properly transformed data in conjunction with Pb isotopes technique.