关键词: 土壤, 重金属, 土地利用方式, 累积

Abstract: In order to investigate accumulation of heavy metals (As, Cd, Cr, Co, Cu, Pb, Ni, V, Zn, Hg) in topsoils different in land use in Southeast Tianjin, soil samples were collected from places different in land use, i.e. industrial land, residential land and agricultural land, for analysis of contents of the heavy metals in the topsoils. Accumulations of the heavy metals were characterized with the single factor index method and the Nemerow comprehensive index method. Results show that industrial lands were quite high in accumulation of Cd, As, Co, Ni and Zn; residential lands were inaccumulation of Cd, As, Co, Zn and Pb; and agricultural lands were in accumulation of Cd, As, Co and Zn. In the studied area as a whole, Cd was heavily accumulated, As moderately accumulated, and Co, Cu, Pb, Ni, V and Zn slightly accumulated; and Cr and Hg was quite close to their respective background value. The evaluation using the Nemerow comprehensive index method indicated that the heavy metals in the soils of most parts of the studied area accumulated to a moderate or severe degree, and by means of the evaluation using the Nemerow comprehensive index method, the three types of land use displayed an order of agricultural land > industrial land > residential land. Comparing with other regions of China, the studied area is obviously higher in accumulation of Cd, As and Co in surface soil.

Key words: soil, heavy metal, land use type, accumulation