Abstract:
To study the quality of the arable soil in peri-urban area of Huangshi City, the present research focused on analyzing heavy metals distribution characteristics, assessed its risk to environment, and subsequently identified its sources by multivariate statistical analysis based on high-density topsoil and subsoil sampling. The results show that the content of heavy metals in the soil isas follows: As (5.2×10
-6~155.9×10
-6), Pb (19.2×10
-6~426.1×10
-6), Hg (0.012×10
-6~1.823×10
-6), Cd (0.03×10
-6~4.59×10
-6), Zn (34.8×10
-6~529.6×10
-6), Ni (8.5×10
-6~86.2×10
-6), Cu (16.52×10
-6~104.39×10
-6) and Cr (51.2×10
-6~145.5×10
-6). The average content of Cd exceeds the regional soil environmental background value, and Cd even exceeds the soil risk screening value of agricultural land. Heavy metal pollutants are mainly concentrated in the topsoil above 40 cm. Among the land use types, paddy lands and dry lands are heavily polluted, and Cd, As and Pb are the main pollutants. In paddy lands, As, Pb, Cu and Zn exhibit slight pollution, Cd and Hg exhibit moderate pollution, whereas Cr and Ni do not exhibit pollution. In dry lands and forest lands, As, Pb and Hg exhibit slight pollution, Cd exhibits moderate pollution and Cr, Cu, Ni and Zn do not exhibit pollution. The multivariate statistical analysis indicates that Cr and Ni in the soil of the study area are of natural origin and related to the parent material of the soil. Cd, Pb, As and Hg are mainly of anthropogenic pollutants, which is related to high-intensity industrial and mining production and sulfide mineral acidification release in Huangshi City.However Cu and Zn constitute mixed sources, partly from soil environmental background, and partly from human activities and industrial production emissions.