Concentration, Distribution, and Influencing Factors on Soil Selenium in Guangzhou

The concentration and distribution of Selenium (Se) in the soils in the city of Guangzhou, as well as the factors affecting them were investigated. Se content in soil samples collected from areas in the city was determined by the hydride generation atomic absorption spectrometry. The results indicated that Se was higher in the surface layer of the soil. The total Se in soil ranged from 0.02 mgkg-1 to 2.87 mgkg-1 with a GM of 0.314mgkg-1, and the available Se from 1.01 gkg-1 to 115.01 gkg-1 with a GM of 19.879gkg-1. A significant variation on the levels of Se contamination in the municipal areas was observed. The more highly contaminated regions included the eastern part of south Nansha District, Panyu District, and Zengcheng District. The soil Se concentration and distribution appeared to be affected greatly by the type and properties of the soil. Under the acidic condition, the sandy clay and granite soil rich in organic matters tended to have high concentrations of Se. It appeared that pH, organic matters, and CEC all contributed to the variation on the concentration and distribution of Se in the soil throughout the city.