The Effect of Highway on Heavy Metal Accumulation in Soil in Turfy Swamps, Northeastern China
2017
Wang, Hong | Nie, Lei | Xu, Yan | Lv, Yan
A detailed investigation was conducted to study the effect of highway on the accumulation of heavy metals in soils of turfy swamps. The concentrations of Cr, Zn, Cu, and Cd showed a decreasing trend with increasing distance from the road, while such trend was not identified in Pb, Ni, Co, and As. The results of factor analysis and cluster analysis indicated that Cr, Zn, Cu, and Cd were in a closer relationship than other metals and might be derived from common sources. The soil samples from JY and LQ sites with the highest traffic volume had the highest heavy metal concentrations of the three highways, while the concentrations of Cr and Cu were significantly positively correlated with traffic volumes (p < 0.05). Contamination levels of traffic-related metals were evaluated using the geo-accumulation index (I gₑₒ) and enrichment factor (EF) in turfy soil. The I gₑₒ index for Cr, Zn, Cu, and Cd varied from unpolluted to the heavily polluted, and the enrichment factor (EF) ranged from 0.44 (no enrichment) to 8.38 (significant enrichment) at JY and LQ site. For HSD site, the I gₑₒ index and EFs of Cr, Zn, and Cd in turfy soils were lower than that in JY and LQ, ranged from uncontaminated to moderate contamination and no enrichment to moderate enrichment, respectively. The I gₑₒ index and EFs of Cd were higher than 1 among all three sites. Therefore, Cd should be paid more attention to avoid potential risk to the flora and fauna in turfy swamps. The affected area of traffic-related metals was <30 m from the highway; this may be due to the abundant precipitation and long cold winter in Changbai Mountain area. The heavy metals could move with rainfall runoff and snowmelt in both particulate and dissolved forms.
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