Distribution of Polybrominated Diphenyl Ethers in Sediments of the Pearl River Delta and Adjacent South China Sea

Abstract

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 differenttypes 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.

Bioaccumulation of Highly Hydrophobic Organohalogen Flame Retardants from Sediments: Application of Toxicokinetics and Passive Sampling Techniques

“…All of the HHOFR concentrations in the spiked sediments were within the range of previously reported values in South China, where as high as 7.3, 1.8, 5.4, and 2.1 μg/g dry weight (dw) of deca-BDE, DBDPE, anti-DP, and syn-DP have been detected, respectively. 8,25 Dissolved oxygen (5.4 ± 0.4 mg/L), pH (7.6 ± 0.2), temperature (23.6 ± 0.8°C), conductivity (316 ± 10 μs/cm), and ammonia (< 0.7 mg/L) were all within tolerance limits for L. variegatus throughout the bioaccumulation tests. 11 The worms in the spiked and field collected sediments behaved similarly to those in the controls.…”

Separation of polybrominated diphenyl ethers in fish for compound-specific stable carbon isotope analysis

“…Generally, deca-BDE (BDE-209) is the most abundant PBDE congener in abiotic matrices such as dust and sediments (Harrad et al, 2008;Mai et al, 2005), which is consistent with industrial PBDE consumption patterns. However, the most frequently detected congeners in biota, and especially in aquatic biota, are the less brominated congeners (tri-to hexa-BDEs) (de Wit, 2002;Watanabe and Sakai, 2003).…”

Short-chain chlorinated paraffins in marine organisms from the Pearl River Estuary in South China: Residue levels and interspecies differences

“…Many studies demonstrate that the Pearl River Delta region have become a hotspot area for persistent halogenated compound contamination due to rapid industrialization and urbanization, and intensive e-waste recycling activities (Fu et al, 2003;Mai et al, 2005aMai et al, , 2005b. High levels of ∑SCCPs were observed in various environmental matrices such as sediment (320-6600 ng·g − 1 dry weight, dw), soil (18 ng·g − 1 dw, average), and air samples (18 ng·m − 3 , average) obtained from this region (Chen et al, 2011;Wang et al, 2013).…”

“…The Pearl River Estuary has been acting as an important reservoir for persistent halogenated compounds derived from the Pearl River Delta, which may pose negative impacts to local coastal ecosystems (Fu et al, 2003;Mai et al, 2005aMai et al, , 2005b. High levels of persistent halogenated compounds, including Dichlorodiphenyltrichloroethane and its metabolites (DDTs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), have been detected in biota from the Pearl River Estuary (Sun et al, 2015a,b).…”