Heavy metal contamination, sources, and pollution assessment of surface water in the Tianshan Mountains of China

Abstract

In order to gain insight into heavy metal contamination occurring in the surface water of the Tianshan Mountains in northwest China, we collected surface water samples from there, tested heavy metals Pb, Ni, Cd, Co, Hg, As, Cu, Mn, Zn, and Cr, and then we analyzed the data using typical analysis, multivariate statistical, and pollution index methods. Results showed that (1) the order of the average values of the ten kinds of heavy metals in all the water samples was as follows: Zn > Mn > Cu > Co > Ni > Pb > Cr > As > Hg > Cd. The maximum variation coefficients of Zn and Pb were 138.96 and 145.86 %, respectively, indicating that these heavy metal concentrations varied largely between different sampling locations. (2) Research showed the average concentrations of Pb, Cd, As, Cu, Zn, and Cr were all within the national surface water standard of class IV and those of As, Cu, Mn, and Cr were all within the range of the Drinking Water Guidelines from the WHO, indicating the surface water of the Tianshan Mountains is clean. (3) Multivariate statistical analysis showed that Cu, Cd, Mn, Hg, Zn, and Pb have close correlations, and they mainly came from artificial sources; while Ni, As, Co, Cu, and Cr mainly came from natural sources. The results of correlation analysis, principal component analysis, and cluster analysis are consistent. (4) Pollution evaluation showed the values of comprehensive pollution index (WQI) of ten kinds of heavy metals in three sections were all lower than 2, suggesting the low levels of pollution, while the over-limit ratios of Pb and Zn in water samples of the middle Urumqi-Akesu section, As in the western Zhaosu-Tekesi section, and Pb, Hg, and Zn in the eastern Balikun-Yiwu section were all above 10 %. This research shows that recent economic development of the Tianshan Mountains has negatively influenced the heavy metal concentrations in the surface water, although the concentrations of the ten kinds of tested heavy metals are relatively low.

Lead Levels in the Bones of Small Rodents from Alpine and Subalpine Habitats in the Tian-Shan Mountains, Kyrgyzstan

“…Many studies have shown that Tian-Shan is one of the mountain ranges in central Asia with the largest anthropogenic sources of heavy metals [4][5][6][7][8]. Pb, Cd and Cu concentrations from the Inilchek ice core (central Tian-Shan) reflect declines during the 1980s concurrent with Soviet economic declines, however, due to the rapid industrial and agricultural growth of western China, Pb, Cd and Cu trends increased during the 1990s [4].…”

Lead Levels in the Bones of Small Rodents from Alpine and Subalpine Habitats in the Tian-Shan Mountains, Kyrgyzstan

“…Mountains are amongst the most fragile environments in the world [3]. Many studies have shown that Tian-Shan is one of the mountain ranges in central Asia with the largest anthropogenic sources of heavy metals [4][5][6][7][8]. Pb, Cd and Cu concentrations from the Inilchek ice core (central Tian-Shan) reflect declines during the 1980s concurrent with Soviet economic declines, however, due to the rapid industrial and agricultural growth of western China, Pb, Cd and Cu trends increase during the 1990s [4].…”

Determination of Spatiotemporal Variations in Heavy Metal Concentration through Orontes River

“…Even though there are many studies regarding with heavy metal concentration in surface waters worldwide (Ma et al, 2015;Zhaoyong et al, 2015;O'Neill et al, 2015;Dević et al, 2016), concentration of heavy metals in a surface water depends upon factors specific to that surface water like substrate sediment concentration, water chemistry, self-purification capacity of river system and anthropogenic activities taking place in the area (Förstner and Prosi, 2013;Islam et al, 2015). Therefore, monitoring and evaluating heavy metal concentrations in water bodies is a case-specific issue.…”