State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China; College of Nature Conservation, Beijing Forestry University, Beijing 100083, PR China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, PR China.
Chemosphere. 2014 Sep;110:8-16. doi: 10.1016/j.chemosphere.2014.03.001. Epub 2014 Apr 4.
The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the soils from industrial, wharf, cropland, milldam and natural wetland sites to characterize their distributions, toxic levels and possible sources in the Pearl River Estuary and identify their relationships with soil organic matter (SOM) and water-stable aggregates (WSAs). Our results indicate that the average concentration of total PAHs in this region reached a moderate pollution level, which was higher than that in other larger estuaries in Asia. The average level of total PAHs in industrial soils was 1.2, 1.5, 1.6 and 2.3 times higher than those in soils from wharf, cropland, milldam and natural wetland sites, respectively. Greater accumulation of PAHs occurred in the middle and/or bottom soil layers where 3-ring PAHs were dominant. Industrial soils also exhibited the highest toxic levels with the highest toxic equivalent concentrations of PAHs, followed by wharf and milldam soils, and the cropland and wetland soils had the lowest toxicity. The diagnostic ratios suggested that PAHs primarily originated from biomass and coal combustion at industrial and milldam sites, and petroleum combustion was determined to be the primary source of PAHs at the wharf, cropland and wetland sites. Both 3-ring and 4-ring PAHs in the milldam and wharf soils were significantly positively correlated with the SOM, whereas the 4,5,6-ring PAHs and total PAHs in industrial soils and the 2-ring PAHs in cropland soils were significantly negatively correlated with the SOM. In addition, large WSAs also exhibited a significant positive correlation with PAHs.
研究采集了珠江口工业、码头、农田、水坝和自然湿地等不同土地利用类型土壤中的 16 种多环芳烃（PAHs），分析其含量、组成特征、毒性水平及来源，探讨其与土壤有机质（SOM）和水稳性团聚体（WSAs）的关系。结果表明，该区域土壤中多环芳烃总浓度处于中等污染水平，高于亚洲其他大型河口。工业土壤中总多环芳烃平均浓度分别是码头、农田、水坝和自然湿地土壤的 1.2、1.5、1.6 和 2.3 倍。多环芳烃在中、底层土壤中具有更高的含量，三环多环芳烃占主导地位。工业土壤中多环芳烃毒性水平最高，毒性当量浓度最大，码头和水坝土壤次之，农田和湿地土壤毒性水平最低。特征比值分析表明，工业和水坝土壤中多环芳烃主要来源于生物质和煤炭燃烧，码头、农田和湿地土壤中多环芳烃主要来源于石油燃烧。水坝和码头土壤中的三环和四环多环芳烃与 SOM 呈显著正相关，而工业土壤中的四环和六环多环芳烃以及总多环芳烃，以及农田土壤中的二环多环芳烃与 SOM 呈显著负相关。大粒径 WSAs 与多环芳烃也呈显著正相关。
