Geographical distribution and risk assessment of persistent organic pollutants in golden threads (Nemipterus virgatus) from the northern South China Sea

Abstract

Fish are often used as good bioindicators to monitor the occurrence of persistent organic pollutants (POPs) on different scales in recent years. Forty-five golden threads (Nemipterus virgatus) were collected from six sampling sites in the northern South China Sea (SCS) to investigate the geographical distribution of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PBDEs, PCBs, and DDTs ranged from 1.3-36.0, 2.3-76.5, 8.3-228 ng/g lipid weight, respectively. The highest PBDEs and DDTs concentrations were found in golden threads from Shantou, owing to the intensive electronic waste recycling activities and rapid development of agriculture. Samples from Haikou had the highest levels of PCBs, probably due to the existence of many shipbuilding yards in the past years. The concentrations of PBDEs and PCBs were found in a decreasing trend from east to west and from north to south, while DDTs concentrations had no obvious trend in the distribution. PCBs were the most prevalent contaminants in Xiamen and Yangjiang, while DDTs were the dominant compounds at the other four sampling sites. Different profiles of POPs at each sampling site may attribute to different pollution sources in the northern SCS. Ratios of (DDD + DDE)/DDTs in golden threads suggested the probability of fresh input of DDT in the northern SCS. The estimated daily intakes of PBDEs, PCBs and DDTs were 0.030-0.069, 0.167-0.258 and 0.105-1.88 ng/kg/day, respectively, which were significantly lower than the acceptable daily intake, suggesting that consumption of golden threads from the northern SCS would not subject the residents in the coastal areas of SCS to significant health risk.

Persistent Halogenated Organic Pollutants in Deep-Water-Deposited Particulates from South China Sea

“…Mai et al (2005) [ 77 ] evaluated the spatial and temporal distributions of PBDEs in 66 surface sediment samples from the Pearl River Delta (PRD) and the adjacent SCS and observed BDE-209 and PBDE (nine congeners excluding BDE-209) concentrations ranging from 0.4 to 7340 and from 0.04 to 94.7 ng/g d.w., respectively. Bioaccumulation of POPs such as PCBs, PBDEs, and PCDD/Fs has already been observed in SCS marine organisms such as fish [ 67 , 102 , 103 , 104 ]; marine mammals, such as dolphins and porpoises [ 105 , 106 ]; crabs [ 107 ]; whales [ 15 ]; octopuses [ 107 ]; and striated cones [ 107 ]. The POPs in the SCS oceanic atmosphere and sediments and PRD sediments indirectly reflect the POPs in SCS deep-ocean-deposited particulates detected in the present study, which further explains their source.…”