Geochemical fractions and risk assessment of trace elements in soils around Jiaojia gold mine in Shandong Province, China

Abstract

Soils located adjacent to the Jiaojia gold mine were sampled and analyzed to determine the degree of which they were contaminated by trace elements (Hg, As, Cd, Pb, Cu, and Zn) in Shandong Province, China. All 18 samples exhibited mean Hg, As, Cd, and Pb concentrations in excess of local background values, while the mean concentrations of Cu and Zn were below the background values. In addition, the concentrations of trace elements in gold smelter (GS) soils were higher than in the gold mine (GM) soils. The result from a modified Tessier sequential extraction procedure was that with the exception of Cu in soils near the smelter, the trace elements were predominantly associated with the residual fraction. After residual fraction, most Hg was mainly humic acid and strong organic fraction, while most As was the humic acid. Cd was associated with the water soluble, ion exchange, and carbonate fractions compared with the other trace elements. Furthermore, Cu, Pb, and Zn were more concentrated in the humic acid and Fe/Mn oxide fraction. The fractions of trace elements were affected by soil pH and Ec (Electrical conductivity). The humic acid fraction of Hg as well as the ion exchange fraction of Cd and Zn displayed negative correlations with soil pH. The strong organic fraction of Hg, the Fe/Mn oxide fraction of Cd, and the carbonate fraction of Zn were positively related to the soil Ec. The strong organic fraction and ion exchange fraction of Zn were negatively related to soil Ec. However, the ion exchange and carbonate fractions of As showed significant positive correlations with soil pH. A calculated individual availability factor (A f (i) ) is used; the values of each trace element in the soils are in the following order: Cu > Cd > Pb > Zn > As > Hg. When combined with a risk assessment code, data suggest that Hg, As, Pb, and Zn levels showed low risk for the environment, whereas Cd levels in soils adjacent to the GM and Cu levels in soils adjacent to the GS showed medium risk to the environment, and Cd levels in soils adjacent to the GS exhibited higher environment risk.

Environmental Pollution by Heavy Metals in the Gold Mining Region of East Cameroon

“…Although toxicity of lead from industrial settings has been relatively controlled, it remains a pervasive toxicant worldwide (Arif et al, 2015;Azizi and Azizi, 2010). In comparison with other similar studies, the mean concentration of Pb in soil of study area was significantly higher than the concentrations reported in Sudan, Ghana and South Africa, respectively by Mushtaha et al (2017), Crentsil and Anthony (2016) and Caspah et al (2016), in addition, this concentration was also higher than obtained in the studies carried out by Feifei et al (2015) and Sijin et al (2015), respectively around a gold mine and Zinc-Lead mining area in China (Table 4). Concentrations of Arsenic (As) range from 0.0 to 16.2 ppm with a mean value of 4.6±4 ppm (Table 2) at Bétaré Oya and from 0.0 to 5.6 ppm with a mean value of 3±2.4 at Batouri (Table 3).…”

“…When the quantities of Cu and Zn in the body increase they become toxic, which can result in damaged and malfunctioning human organs (USEPA, 2013;Bost et al, 2016;Fraga, 2005;Tobias et al, 2013). The level of Zn in this study area was higher than the concentrations found in studies on soils around gold mine in China (Feifei et al, 2015) and Sudan (Mushtaha et al, 2017) but lower than Zn concentration (112.3 ppm) reported in Zinc-Lead mining area in China (Sijin et al, 2015).…”

“…The Pollution Load Index (PLI) is used to comprehensively evaluate the pollution effect of study metals and for each site, it is defined as follows (Caeiro et al, 2015;Feifei et al, 2015):…”

Pollution Assessment of Potentially Toxic Elements (PTEs) in Soils around the Yanzhuang Gold Mine Tailings Pond, Pinggu County, Beijing, China

“…Due to the above facts, soil environmental sampling has become a crucial means to evaluate the anthropogenic pollution with PTEs. Over the past few years, several studies to determine the contamination of PTEs in the soils of neighboring gold mines have been conducted in many countries [ 14 , 15 , 16 , 17 , 18 ].…”

“…The waste of ASGM was discharged to land without any treatment, which will pollute the surrounding soil. In China, it was found that the concentration of Hg in tailings was relatively higher than background concentrations [ 14 ]. Moreover, in Indonesia, ASGM activities in Central Java caused a great deal of Hg pollution to local streams [ 23 ].…”