Chlorinated and Polycyclic Aromatic Hydrocarbons in Riverine and Estuarine Sediments from Pearl River Delta, China

Environmental Pollution 117 (2002) 457–474 www.elsevier.com/locate/envpol Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China Bi-Xian Maia,*, Jia-Mo Fua, Guo-Ying Shenga, Yue-Hui Kanga, Zheng Lina, Gan Zhanga, Yu-Shuan Mina, Eddy Y. Zengb aState Key Lab Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, PO Box 1130, Guangzhou, Guangdong 510640, People’s Republic of China bSouthern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, CA 92683, USA Received 5 January 2001; accepted 3 July 2001 ‘‘Capsule’’: Sediments of the Zhujiang River and Macao Harbor have the potential to be detrimental to biological systems. Abstract Spatial distribution of chlorinated hydrocarbons [chlorinated pesticides (CPs) and polychlorinated biphenyls (PCBs)] and polycyclic aromatic hydrocarbons (PAHs) was measured in riverine and estuarine sediment samples from Pearl River Delta, China, collected in 1997. Concentrations of CPs of the riverine sediment samples range from 12 to 158 ng/g, dry weight, while those of PCBs range from 11 to 486 ng/g. The CPs concentrations of the estuarine sediment samples are in the range 6–1658 ng/g, while concentrations of PCBs are in the range 10–339 ng/g. Total PAH concentration ranges from 1168 to 21,329 ng/g in the riverine sediment samples, whereas the PAH concentration ranges from 323 to 14,812ng/g in the sediment samples of the Estuary. Sediment samples of the Zhujiang River and Macao harbor around the Estuary show the highest concentrations of CPs, PCBs, and PAHs. Possible factors affecting the distribution patterns are also discussed based on the usage history of the chemicals, hydrologic con- dition, and land erosion due to urbanization processes. The composition of PAHs is investigated and used to assess petrogenic, combustion and naturally derived PAHs of the sediment samples of the Pearl River Delta. In addition, the concentrations of a number of organic compounds of the Pearl River Delta samples indicate that sediments of the Zhujiang river and Macao harbor are most likely to pose biological impairment. # 2002 Elsevier Science Ltd. All rights reserved. Keywords: Chlorinated hydrocarbons; Polycyclic aromatic hydrocarbons; Sediments; Distribution; Pearl River Delta 1. Introduction water lagoon, connects the continent with the South China Sea (Fig. 1). Aquatic resources associated with The Pearl River is one of the largest rivers in China, the Pearl River have been a main source for a variety of its deltaic region is characterized by a great number of anthropogenic activities for decades, such as irrigation, tributaries and streams, forming a complicated water- waste disposal, transportation, and seafood harvest- shed called Pearl River Delta within Guangdong Pro- ing, etc. Beneficial uses of the resources are further vince (Fig. 1). Approximately 3.13Â1011 m3 of fresh stimulated by the mild temperature and rich rainfall water annually flow into the South China Sea via eight throughout the year around the region. major outlets (GPA/GTPA, 1994): Humen (5.78Â1010 The economy growth and urbanization have acceler- m3/year), Jiaomen (5.42Â1010 m3/year), Hongqilimen ated in the last two decades around Pearl River Delta, (2.00Â1010 m3/year), Hengmen (3.51Â1010 m3/year), as a result of the drastic economic reform initiated in Modaomen (8.84Â1010 m3/year), Jitimen (1.89Â1010 early 1980s. The population increased from 50.6 mil- m3/year), Hutiaomen (1.94Â1010 m3/year), and Yamen lions in 1979 to 69.0 millions in 1996, while the gross (1.88Â1010 m3/year). The Estuary, a V-shaped, shallow- domestic production in 1997 experienced a 13.5% annual increase in the region compared to an average * Corresponding author. Tel.: +1-86-20-8529-0179; fax: +1-86-20- increase of 7.8% nationwide (GSB, 1998). Explosive 8529-0706. increases in industrial and agricultural productivities E-mail address: [email protected] (B.-X. Mai). and growing population have led to serious concerns 0269-7491/02/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved. PII: S0269-7491(01)00193-2 458 B.-X. Mai et al. / Environmental Pollution 117 (2002) 457–474 Fig. 1. Map showing sampling locations and surrounding areas in the Pearl River Delta and Estuary. The numbers indicate the eight major outlets to the South China Sea: 1, Humen; 2, Jiaomen; 3, Honqilimen; 4, Hengmen; 5, Modaomen; 6, Jitimen; 7, Hutiaomen; 8, Yamen; 9, Huangbu harbor; 10, Guangzhou Petrochemical Coporation; and 11, Fangchun. about whether the aquatic environment is adequately impact of anthropogenic activities on aquatic systems. protected and the natural resources are properly utilized The riverine and estuarine sediment samples of the Pearl (GPA/GTPA, 1994). Recent studies indicated that River Delta and Estuary have been previously analyzed chlorinated and non-chlorinated hydrocarbons were for trace metals (Ke, 1991; Chen and Zhou, 1992), and present in water samples from various locations around organic compounds were basically measured in the Pearl River Delta (Yang et al., 1997) and in aerosols estuarine sediment samples (European Commission, sampled in various cities of Guangzhou, Hong Kong, 1998; Wu et al., 1999). and Macao (Fu et al., 1997). Since sediments are the In order to understand and assess the impact of dras- ultimate sinks and reservoirs of contaminants, analyses tically increased anthropogenic activities on the aquatic of sediment samples are an important tool for assessing ecosystem of Pearl River Delta, initial efforts are much B.-X. Mai et al. / Environmental Pollution 117 (2002) 457–474 459 needed to determine the current sediment contamina- numerous industrial and agricultural settings in tion status. We attempted to fulfill this objective by Guangzhou, sediments of the Zhujiang River are measuring chlorinated pestides (CPs), including hexa- expected to be heavily contaminated with pollutants of chlorocyclohexanes (BHCs), DDTs and other non-DDT industrial and domestic wastes. Shiziyang river, which is chlorinated pesticides and PCBs, as well as polycyclic about 50 km long and on average 2200 m wide, with an aromatic hydrocarbons (PAHs) of the sediment samples average water depth of 6.6 m, is situted downstream to collected from rivers and estuary around the Delta. The Zhujiang river. The Shiziyang River receives inflows chosen target analytes are all potentially carcinogenic from Zhujiang River and Dongjiang river, and drains and have not been measured in the riverine sediment into the Lingding Bay through the Humen Outlet samples of the Delta. The data were used to evaluate the (Fig. 1). Another tributary selected for sampling is the distribution pattern of organic contaminants and to Xijiang River, located on the southwest side of the identify possible input sources. Delta (Fig. 1). It is approximately 150 km long and on average 1235 m wide, with an average water depth of 15 m. Historically, areas drained by Xijiang river have 2. Materials and methods been less developed than the area drained by Zhujiang and Shiziyang rivers. The Xijiang river flows out the 2.1. Study site and sample collection southwestern region of the Estuary through the Mod- aomen, Jitimen, and Hutiaomen outlets (Fig. 1). Two major tributaries within Pearl River Delta were Lingding Bay is located at the northern part of the chosen for sampling. The first tributary consists of two Estuary and receives runoff from four outlets, i.e. waterways: Zhujiang River and Shiziyang River (Fig. 1). Humen, Jiaomen, Hongqilimen, and Hengmen (Fig. 1). The Zhujiang River, on the northeast side of the Delta, In addition, the estuary is also greatly impacted by is approximately 78 km long, with an average width of inputs from Macao and Hong Kong, one of the most 430 m, and an average water depth of 4.8 m. It runs populated regions in the world. across the City of Guangzhou, the most urbanized and A total of 17 stations were selected for sampling heavily populated district in Guangdong Province. With (Table 1), for which six stations were located along an official population of 6 million inhabitants and Zhujiang and Shiziyang Rivers , four along Xijiang River, Table 1 List of sampling stations and the sediment characteristics Station Latitude/longitude Water depth (m) Sediment type TOCa (%) Zhujiang River ZB01 2306.210 N/11314.240 E 8 Silty clay, black gray 1.98 ZB02 2306.770 N/11322.660 E 4 Sandy silt, black gray 1.52 ZB03 2305.050 N/11323.460 E 9 Clay, black gray 2.10 Shiziyang River ZB04 2259.960 N/11330.910 E 4 Clay, yellow gray 1.49 ZB05 2259.960 N/11330.940 E 4 Clay, yellow gray 1.42 ZB06 2254.220 N/11334.660 E 6 Clay, yellow gray 1.07 Xijiang River ZB07 2246.440 N/11304.030 E 7 Silty clay, khaki gray 1.10 ZB08 2236.560 N/11308.020 E 6 Clay, yellow gray/gray 0.54 ZB09 2230.920 N/11310.220 E 3 Silty clay, khaki gray 1.17 ZB10 2216.870 N/11320.890 E 7 Sandy silt, yellow gray/black gray 1.10 Lingding Bay (estuary) ZB11 2235.750 N/113400 E 2 Clay, yellow gray/gray 1.16 ZB12 2228.040 N/11356.350 E 5 Silty clay, yellow gray/gray 0.64 ZB13 2223.200 N/11347.430 E 5 Sandy silt, yellow gray 1.28 ZB14 2223.160 N/11337.960 E 3 Clay, khaki 1.15 ZB15 2214.220 N/11336.170 E 8 Sandy silt, yellow gray/gray 0.96 ZB16 2210.890 N/11333.290 E 3 Sandy silt, khaki/black gray 0.80 Macao Harbor (estuary) ZB17 2210.8912.170 N/11333.292.030 E 3 Sandy silt, khaki/black gray 1.66 a TOC, total organic carbon. 460 B.-X. Mai et al. / Environmental Pollution 117 (2002) 457–474 and seven around the estuary (Fig.

Load more