Heavy Metal Contamination of Roadside Surficial Soils, Atmospherically Deposited Dusts, and Ornamental Plants from Urban Arteries in Nanjing City

摘要

Surficial soil, atmospherically deposited dusts on windows, and two selected ornamental plants-Begoniaceae and Petunia were sampled at roadside along urban arteries in Nanjing City in China. Concentrations of metals (Pb, Cd, Cu, Zn, Ni, Cr, Co, Mn, Sc, Ti, V, Fe, Ba) were analyzed using inductively coupled plasma atom emission spectrometry and inductively coupled plasma mass spectrometry. Enrichment factor (EF) and geoaccumulation index (Igeo) were used to assess the enrichment and contamination levels of the soils and atmospherically deposited dust. ANOVA analysis shows that significant differences on the metal levels were found between surficial soil samples and atmospherically deposited dusts except for Sc, V and Ti. EF values for Cr, Cu, Ni, Pb, Zn, Mn, Sc, V, Ba, Co, Ti and Fe in the surficial soils were all below 2.0 except for Cd (11.5 for Begoniaceae and 13.2 for Petunia). Igeo values were below 0 for Cr, Cu, Ni, Pb, Mn, V, Ba, Co, Ti and Fe, and between 2 and 3 for Cd in the soil samples. To the atmospherical ly deposited dusts, EF values were below 2.0 for Mn, Sc, V and Ti, between 2.0 and 5.0 for Cr, Ni, Ba and Fe, between 5.0 and 20 for Cu, Pb and Zn, and 49.7 for Cd. Igeo values were below 0 for Mn, Sc, V and Ti, between 0 and 1 for Cr, Ba, Co and Fe, between 1 and 2 for Ni, between 2 and 3 for Cu, Pb and Zn, between 4 and 5 for Cd in the atmospherically deposited dusts. Based on EF and Igeo values, atmospherically deposited dusts were more heavily polluted by heavy metals than soils, and Cd was the most imp ortant contaminants, then Zn, Pb and Cu. Significant differences were found on the tissue distribution of metals between Petunia and Begoniaceae. The order of metal levels in different tissue was leave>root>flower>stem for Petunia, and root>leave>flower>stem for Begoniaceae.