Distribution characteristics and correlation of heavy metals in soil and total suspended particles of Urumqi City

Abstract

In this study, soil and total suspended particles samples (TSP) were collected from different soil layers in four functional areas of Urumqi City, Northwest China, and electric heating plate digestion and inductively coupled plasma-optical emission spectrometry (ICP-OES) were used to determine the mass fractions and spatial distribution of six heavy metals. The aim was to determine the effects of human activities on the urban soil and atmosphere and provide a theoretical basis for environmental protection and management in Urumqi. The results showed that: (1) The average mass fractions of Cr, Cu, Mn, Ni, Pb, and Zn were 129.24, 42.445, 691.70, 48.705, 31.36, and 126.5 mg kg−1, respectively; the average mass fractions of Cr, Zn, Ni, and Cu exceeded the limit of the national soil standard; the pollution indexes were 1.44, 1.27, 1.22, and 1.21, respectively. (2) The heavy metal contents of surface soils are higher in the industrial, traffic, and cultural and educational areas than in the clean park area; in the vertical section, the heavy metals in the industrial, traffic, and culture and education areas show a weak epimerism, and the soil in the park area shows a good primitivity. (3) The ratios of the highest to lowest concentration of heavy metals in TSP can be ranked as follows: Pb (9.75) > Mn (2) > Ni (1.48) > Cr (1.36) > Cu (1.32) > Zn (1.17). (4) The correlations of heavy metals between the soil and TSP are significant, indicating that dry and wet deposition significantly affect the heavy metal content of the soil.