Assessment of Spatial Distribution and Pollution With Heavy Metals in Roadside Soils Along Xi'an-Baoji Highway in Northwest China

Abstract

Xi'an-Baoji Highway is one of the oldest and most important highways in northwest China. In this study, the concentrations (0-20 cm) of Pb, Zn, Cu and Cr at 5-1000 m distances in the roadside soils along Xi'an-Baoji Highway were experimentally determined to analyze their spatial distribution and evaluate their contamination levels. The spatial distribution (mg·kg -1 ) of Pb, Zn, Cu and Cr at 5-1000 m distances from the both roadsides (North/South) is, respectively, 23. 81-38.45/24.54-36.90, 72.79-121.98/ 76.91-130.60, 24.58-41.60/23.82-37.31, and 63.83-85.26/64.30-85.94 at Chencang District section, while it is 23. 41-45.76/20.95-42.50, 74.62-135.54/75.15-127.25, 23.94-35.71/22.04-36.91, and 63.82-85.84/64.33-88.53, respectively, at Caijiapo section. Regarding the Pb, Zn, Cu and Cr at Mei County section, it is 25. 47-40.89/23.56-32.72, 74.15-131.24/72.67-118.15, 24.00-37.61/25.68-44.99, and 64.00-89.22/61.90-85.58, respectively. Integrated evaluation via the contamination factor (C f ), contamination degree (C d ) and pollution level index (PLI) showed the moderate pollution level. While geoaccumulation index (I geo ) revealed that all evaluated metals were almost unpolluted (0＜I geo ), only part heavy metal of individual sampled sites were unpolluted to moderately polluted (0≤I geo ＜1). The correlation analysis shown these metals are significantly associated with each other. Interelement correlation is as follows: Pb-Cr＞Pd-Cu＞Zn-Cu＞Pd-Zn＞Zn-Cr＞Cu-Cr. Moreover, the hierarchical cluster analysis suggested that Pb and Zn might be from the identical anthropogenic and natural source while Zn and Cr might have the same original source in the roadside soils along Xi'an-Baoji Highway in Northwest China.

Spatial Dissemination of Some Heavy Metals in Soil Adjacent to <i>Bhaluka</i> Industrial Area, Mymensingh, Bangladesh

“…Out of 10 sampling sites, 8 sites at 0 m and only 1 site at 30 m distance from waste canal had PLI values >1.0, indicates contaminated. Fan [35] also observed moderate pollution level of soils at 5-1000 m distances from the both roadsides of Xi'an-Baoji Highway, China, as per PLI values. The PLI can provide some understanding to the public of the area about the quality of soils of their environment and it can indicate the trends over time and area.…”

“…Four samples at 0 m and 3 samples at 60 m distance for Pb were exhibited moderately polluted soil quality. Soils at 5-1000 m distances from the both roadsides of Xi'an-Baoji Highway, China also revealed unpolluted to moderately polluted soil quality for Pb, Cu and Zn [35]. Table 3.…”