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The Shen-Fu region is an important urban area in northeast China. We report on a study of the distribution of polybrominated diphenyl ethers (PBDEs) in representative topsoil from this region. In the summer of 2016, 72 soil samples from three cities (Shenyang, Fushun, and Shen-Fu New City) were collected, which covered four land use types:urban, rural residential, cultivated, and woodland. We report on the concentrations, compositions, and distributions of 14 PBDEs in soil and explore their sources, and additionally undertake human exposure analysis and health risk assessments. The results showed that the concentration of ∑ 14 PBDEs in the topsoil ranged from 0.279-50.719 ng·g -1 (dry weight), with a mean of (10.466±9.246) ng·g -1 . The concentrations of PBDEs was ranked for the cities as:Fushun > Shenyang > Shen-Fu New City > background, and for different land use types as:urban land > rural residential land > cultivated land > forest. Deca-PBDE had the highest proportion of all congeners, accounting for 81.25%-89.23% of all PBDEs. Source analysis indicated that commercial Deca-PBDE was the main source, contributing 66.06% of the total Deca-PBDE according to principal component analysis/multiple linear regression (PCA-MLR). Among five different age groups assessed for exposure, children in Fushun had the highest exposure dose:(20.98±25.01) ng·(kg·d) -1 . In terms of different land types, the highest exposure dose was for children living in urban areas:(18.54±20.27) ng·(kg·d) -1 . The non-oncogenic health risks in the Shen-Fu region are of a relatively low level.

To study the vertical distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) in the soils from different land use types during urbanization, three land use types (urban land, cultivated land, and woodland) were selected in the eastern part of Shenyang, where urbanization is occurring rapidly. In each case, five soil samples were obtained from different depths (0-1 m). Change in the concentrations of PAHs, vertical migration factors, and the distribution and sources of PAHs were analyzed in the vertical soil profiles. Total concentrations of PAHs in the different soil type were ordered as follows:city 1 (513.19-12689.04 μg·kg -1 ); dry field (36.18-7196.10 μg·kg -1 ); paddy field (70.92-747.53 μg·kg -1 ); city 2 (19.39-636.47 μg·kg -1 ); and woodland (4.79-349.24 μg·kg -1 ). PAHs were mainly trapped in shallow soils in urban and forest land, but can migrate deeper into the soil profile in cultivated land. High-ring PAHs were abundant at depths of 0-30 cm, while low-ring PAHs were abundant deeper in the soil profiles. SOM had a significant effect on the vertical distribution of PAHs, and the physical and chemical properties of PAHs had a significant influence on their migration ability. However, combustion sources from industrial activities and transportation in the region are still considered the main sources of PAHs despite the fact that some low-ring PAHs derive from petroleum product inputs.