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In order to expound the present situation and the potential risk of soil cadmium (Cd) in Guangxi, the paper collected and analyzed literatures about soil Cd in Guangxi which were published in recent 20 years. Based on the uniform criteria, 60 references were selected involving more than 30 areas in Guangxi, 7 090 samples. The paper summarized the distribution of soil Cd content distribution and the situation of soil Cd content exceeding the standard in Guangxi, so as to provide reference for relevant research, environmental policy making and environmental management. Results show that the soil Cd content in Guanxi ranges 0.040-244.1 mg·kg-1, with arithmetic mean and geometric mean 12.23 and 1.884 mg·kg-1, respectively. There were great differences in soil Cd concentration distribution between different functional areas. The average background soil Cd content in the research area is 0.153 mg·kg-1. The geometric mean of Cd content in agricultural soils and urban soils of non-mining areas were 0.467 and 0.320 mg·kg-1, respectively. The geometric mean of Cd content in the soil of mining area and in agricultural soil of mining area were 7.147 and 6.643 mg·kg-1, which were 46.71 and 43.42 times of the background soil Cd content. The majority of farmland soils are maintained at moderate pollution levels. Soils in several counties such as Nandan, Huanjiang, Jinchengjiang and Daxin were greatly affected by the pollution in mining area. There are areas not involved in the collected literatures. We recommend that control measures should be taken in Nandan, Jinchengjiang, Big Huanjiang, Yangshuo and Diaojiang areas, major investigations should be made in Baise Debao, Pingguo, Tiandong and Tianyang aluminum ore producing areas, and monitors on agricultural soil surrounding the mining area should be done. [ABSTRACT FROM AUTHOR]

In order to understand copper concentration and distribution in soil of Xijiang River Basin of Guangxi and evaluate the ecological risk, this paper collected 1 381 dryland soil samples, 729 paddy soil samples, 129 mining soil samples and 293 background soil samples during 2012-2015, and measured the content of copper in soils. According to statistical analysis, the influence of copper accumulation in different types of soil was explored, the spatial distribution of copper content was interpolated through geostatistical analysis and the risk was assessed. The results showed that the geometric mean of copper concentrations was 27.60 mg/ kg. The copper concentrations in dryland, paddy, mining and background soil ranged from 0.3 to 317.91, 3 to 495.81, 7.5 to 2 287.66 and 0.68 to 284.27 mg/kg, and the geometric means were 27.75, 25.19, 79.38 and 21.21 mg/kg, respectively. The copper concentration in mining soil was significantly higher than in other soils. Compared to baseline value, the corresponding exceeding rate of mining, dryland and paddy soil were 33.25%, 3.76% and 0.68%, respectively. The spatial pattern of copper content in Xijiang River Basin showed medium autocorrelation with strong structural variability. Clean soil occupied 61% in Xijiang River Basin, while 36% of soil belongs to light pollution soil which mainly distributed in Nandan, Du’an, Wuxuan and Guiping counties where lead-zinc ores are concentrated. Generally speaking, copper content in soil of Xijiang River Basin had some accumulation but the pollution was not serious and it was assessed to be safe. Besides, the risk should be prevented in the areas of Nandan, Du’an, Wuxuan and Guiping counties. [ABSTRACT FROM AUTHOR]

Guangxi was known as “the hometown of nonferrous metals”, and the problem of heavy metal pollution in soil was very prominent. Based on the published papers about arsenic(As) in Guangxi since 1989 and our previous work in Guilin, Nandan and Huanjiang, this study explored the concentration and pollution distribution of As in soils and sediments in Guangxi. Totally, 3 045 soil samples and 477 sediment samples were collected. Results showed that: 1) In Guangxi, the As polluted soil mainly distributed in the northwest of Guangxi, especially in the Diaojiang and Jinchengjiang River basins. 2) Mining activity affected the accumulation of As in soil significantly. The soils with concentrations of As from high to low in order were non-agricultural soil in industrial and mining areas (140.5 mg/kg), agricultural soil in industrial and mining areas (80.68 mg/kg), agricultural soil in non-industrial and mining areas (19.11 mg/kg) and urban soil (18.35 mg/kg). Compared with the standard of soil environment quality in China (GB15618-1995), 89.4%, 69.0%, 18.7% and 12.1% of the above four types of soil samples exceeded the standard limit. The most seriously polluted samples in agricultural soil were all in Nandan. 3) The accumulation of As in marine sediments (8.76 mg/kg) and river sediments in non-industrial and mining areas (16.11 mg/kg) were not remarkable. As for river sediments, the pollution levels of As in industrial and mining areas (283.5 mg/kg) were much higher than those in non-industrial and mining areas. The affected areas mainly distributed in the Diaojiang and Dahuanjiang basins. In order to control the environmental risk, it is recommended to carry out the survey of As pollution in the surface sediments of the main river systems in Guangxi, especially in the river of Diaojiang, Dahuanjiang and Jinchengjiang, and the pollution in Nandan areas should be controlled and prevented and the contaminated soil should be repaired. [ABSTRACT FROM AUTHOR]