Abundances, Depositional Fluxes, and Homologue Patterns of Polychlorinated Biphenyls in Dated Sediment Cores from the Pearl River Delta, China

• Published in: Environmental science & technology Vol. 39; no. 1; pp. 49 - 56
• Main Authors: Mai, Zeng, Eddy Y, Luo, Yang, Zhang, Gan, Li, Sheng, Fu
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.01.2005
• Subjects: Analysis methods; Applied sciences; Atmospheric pollution; China; Environmental Monitoring; Environmental Pollutants - analysis; Environmental Pollutants - history; Exact sciences and technology; Freshwater; Geologic Sediments - chemistry; History, 20th Century; Organic contaminants; PCB; Pollution; Polychlorinated biphenyls; Polychlorinated Biphenyls - analysis; Polychlorinated Biphenyls - chemistry; Power Plants; Rivers; Sediments; Time Factors; Tropical Climate; Water Movements; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - history; Asia; China; Pearl River; ISEW, China, People's Rep., Hong Kong; China, People's Rep., Zhu R; ISEW, Macao; China, People's Rep., Hong Kong; Macao; China, People's Rep; Historical reconstruction; Atmospheric fallout; Pollutant behavior; Troposphere; Mobility; Isotope dating; Sediments; Polychlorobiphenyl; Time variation; Persistent organic pollutant; Cores; Century 20th; Delta; Chlorine Organic compounds; Pollution source inventory; Homologous series; Air pollution; Qualitative analysis; Water pollution; Organic compounds; Quantitative analysis
• DOI: 10.1021/es049015d
• ISSN: 0013-936X

Despite the recent efforts to investigate the distribution and fate of persistent organic pollutants in the tropical and subtropical regions of Asia, very little was known about the temporal change of polychlorinated biphenyls (PCBs) in the environmental ecosystem of China. In this study, three dated sediment cores collected from the Pearl River Delta of southern China were analyzed for a large suite of PCB congeners, from which the temporal profiles of PCB abundances, fluxes, and homologue patterns were constructed. The sedimentary inventories of total PCBs at the sampling sites ranged from 480 to 1310 ng/cm2, at the low end of the worldwide figures. Although production and use of PCBs have been banned or highly restricted in China since the early 1980s, the fluxes of total PCBs continued to increase in the Pearl River Delta sediments. There was a concurrent increase of PCB fluxes and gross domestic product per capita in the region from 1980 to 1997, and a decline of agricultural land use was evident at the same time. Apparently, large-scale land transform since the early 1980s as well as emissions from the PCB-containing electrical equipments were responsible for the sharp rise of PCB fluxes in the recent sediments. The difference in the PCB homologue patterns from 1940 to the mid-1970s was probably indicative of the different timelines of PCB usage in Macao/Hong Kong and mainland China and the different types of technical PCBs commercially used. PCBs were detectable in sediments deposited well before the time frame when production of PCBs began (before 1930) and were relatively enriched in the less chlorinated homologue groups (3Cl and 4Cl PCBs), suggesting the downward mobility of lightly chlorinated PCB congeners in the sediment column.