Identification of the spatial distributions, pollution levels, sources, and health risk of heavy metals in surface dusts from Korla, NW China

Abstract

A total of 54 surface dust samples were gathered from Korla in NW China, and the concentrations of six heavy metal elements, such as Hg, Cd, As, Pb, Cr, and Cu, were determined by standard methods. The geostatistical analysis, multivariate statistical analysis, pollution load index (PLI), and the US EPA health risk assessment model were used to analyze the spatial distribution, pollution, and its potential health risk of heavy metals in surface dusts, and the main sources of heavy metals were also identified. The obtained results indicate that the average concentrations of As in surface dust of Korla is lower than the background values determined in Xinjiang soil, whereas the average concentrations of Hg, Cd, Pb, Cr, and Cu elements exceeded the corresponding background values by factors of 3.71, 1.87, 1.96, 1.14, and 1.29, respectively. The higher concentration of analyzed heavy metals is observed in the northeastern and northern parts in the study area. The pollution level of heavy metals decreased in the following order: Hg > Pb > Cd > Cu > Cr > As. Based on the identified concentrations, the collected dust samples are found to be heavily polluted by Hg and slightly polluted by As, and the remaining elements, Pb, Cd, Cu, and Cr, are found to be low polluted. Furthermore, the PLI values of heavy metals in surface dust vary between 0.74 and 2.74, with an average value of 1.40, at the low pollution level. In addition, As in surface dust in the study area is mainly natural source, while Hg, Cd, Cr, Cu, and Pb are mainly anthropogenic sources. Overall, the carcinogenic and noncarcinogenic health risks of the analyzed elements, instigated mainly by oral ingestion of surface dust, are found to be within the acceptable range for both children and adults. As and Cr are the main noncarcinogenic elements, whereas Cr is the major carcinogenic element among the investigated dust-bound heavy metals in Korla.

Heavy Metal Pollution and Risk Assessment of Surface Dust in the Arid NW China

“…HMs in USD are influenced by natural and anthropogenic sources such as soil parent material, industrial emissions, transportation, and domestic activities [ 19 , 20 ]. Correlation analysis and cluster analysis are often widely used to identify the pollution sources of HMs [ 121 ].…”

“…In addition, dust suspended in the atmosphere continuously enters urban ecosystems under the influence of both gravity and precipitation [ 16 , 17 , 18 ]. Moreover, USD can enter urban water bodies through the surface runoff formed by precipitation and municipal road cleaning, thus leading to the continuous enrichment of many toxic pollutants in water bodies and eventually threatening the growth and reproduction of aquatic plants and animals [ 19 , 20 , 21 ]. In addition, many HMs accumulate in the human body over long periods of time through accidental ingestion, inhalation, and dermal contact, thus causing irreversible damage to human health [ 22 , 23 , 24 ].…”

Characteristics and Risk Assessment of 16 Metals in Street Dust Collected from a Highway in a Densely Populated Metropolitan Area of Vietnam

“…Kamani et al [63] calculated the values of Pi for heavy metals in street dust in Tehran, Iran, obtaining values for Cd (P Cd = 4.77), Pb (P Pb = 4.78), Cu (P Cu = 10.22), and Zn (P Zn = 10.37), that indicated heavy pollution. Hayrat and Eziz [41] also revealed that dust samples from Korla, China were heavily polluted by Cr (P Cr = 3.33), Cu (P Cu = 5.81), Pb (P Pb = 7.32), and Cd (P Cd = 35.0), with the degree of pollution associated with anthropogenic activity. Another study conducted by Wahab et al [21] in Malaysia presented the Pi values of metals in street dust in the Tunku Abdul Rahman road, Kuala Lumpur, where Zn (P Zn = 3.94), Pb (P Pb = 4.20), Cr (P Cr = 5.78), and Cu (P Cu = 8.43) showed high levels of pollution.…”

“…where P i is the pollution index for element i, C i and C b are the concentrations of element i and the background for element i, PLI is the pollution load index, and n is the number of metals analyzed in this study. The five categories of P i and the four categories of PLI [41] are shown in Table S2.…”

“…The CV values of Cu, Pb, Sb, Mo, Se, As, Ni, Cr, Mn, B, V, and Ti showed moderate variability, while the CV value of Co showed low variability. The high CV values of some of the elements showed a strong anthropogenic influence [4,41,46,47]. Detailed information on the mean, standard deviation, min, max, CV, and background concentrations of the 16 metals studied can be found in Table S4 in the Supplementary Materials.…”