Ma Xiaoxuan, Ran Yong, Gong Jian, Zou Mengyao
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, People's Republic of China.
Environ Monit Assess. 2008 Oct;145(1-3):453-64. doi: 10.1007/s10661-007-0054-z. Epub 2007 Nov 30.
The concentration levels, source, and inventories of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in 55 surface vegetable soils in the watershed of the Pearl River Delta (PRD) were analyzed and compared with those of the surface sediments in the Pearl River Estuary (PRE) and northern South China Sea (SCS). The 16 priority PAHs on US EPA list range from 58 to 3,077 microg/kg (average: 315 microg/kg). The concentrations of DDTs and HCHs range from 3.58 to 831 microg/kg (average: 82.1 microg/kg) and from 0.19 to 42.3 microg/kg (average: 4.42 microg/kg). The ratios of DDT/ (DDD+DDE) are higher than 2 in majority of the soil samples, suggesting that DDT contamination still exists. The PAH ratios suggest that the source of PAHs is petroleum, and combustion of fossil fuel, biomass, and coal. The average concentrations of PAHs and the linear regression slope between PAHs and TOC for the soils and the sediments are quite similar. It was estimated that the soil mass inventories at 0-20 cm depth are 1,292 metric tons for PAHs and 356 metric tons for OCPs in the studied region. The average PAHs inventory per unit area for the soil samples investigated in PRD is about 0.86 time that of surface sediments in the Pearl River Estuary, and about 2.43 times that of surface sediments in the northern South China Sea. PAHs in the soils in PRD have similar source to those of the surface sediments in PRE. All of those may suggest that PAHs in PRE and SCS are probably mainly inputted from the soils in PRD via soil erosion and river transport.
分析了珠江三角洲（PRD）流域55个表层蔬菜土壤中多环芳烃（PAHs）和有机氯农药（OCPs）的浓度水平、来源及存量，并与珠江口（PRE）和南海北部（SCS）的表层沉积物进行了比较。美国环保署列出的16种优先PAHs的含量范围为58至3077微克/千克（平均：315微克/千克）。滴滴涕（DDTs）和六氯环己烷（HCHs）的浓度范围分别为3.58至831微克/千克（平均：82.1微克/千克）和0.19至42.3微克/千克（平均：4.42微克/千克）。大多数土壤样品中DDT/（滴滴滴+滴滴伊）的比值高于2，表明仍存在DDT污染。PAH比值表明PAHs的来源是石油、化石燃料、生物质和煤炭的燃烧。土壤和沉积物中PAHs的平均浓度以及PAHs与总有机碳（TOC）之间的线性回归斜率相当相似。据估计，研究区域内0至20厘米深度的土壤质量存量中，PAHs为1292公吨，OCPs为356公吨。珠江三角洲所调查土壤样品的单位面积PAHs平均存量约为珠江口表层沉积物的0.86倍，约为南海北部表层沉积物的2.43倍。珠江三角洲土壤中的PAHs与珠江口表层沉积物的来源相似。所有这些可能表明，珠江口和南海的PAHs可能主要通过土壤侵蚀和河流输送从珠江三角洲的土壤中输入。
