| Halogenated flame retardants(HFRs) are used extensively in domestic and industrial products as addictives to prevent fire. HFRs are detected in various environmental media because of the widespread use. Meanwhile, the residues of HFRs in the environmental media may cause severe environmental and ecological risks as some BFRs have been listed as persistent organic pollutants. Hence, the bans and restrictions of some BFRs have been implemented around the world. The Yellow Sea and Bohai Sea are two important shelf seas which sustain China’s marine economy and coastal urbanization and industrialization. Meanwhile, they are suffering heavily pollution and eutrophication due to the large amount of industrial, domestic, and municipal waste water together with nutrients and pollutants from air deposition pouring in them. Besides, the Laizhou Bay area around Bohai Sea is the largest manufacturing base for BFRs in northern China. However, studies of a BFRs in this region are scarce.In this study, seventeen BFRs were investigated in 51 marine surface sediment samples and 3 river surface sediment samples from the Yellow Sea and nineteen HFRs were determinate in 108 marine surface sediment samples and 35 riverine surface sediment samples from rivers empting into the Bohai Sea and northern Yellow Sea. All the samples were analyzed by gas chromatography- mass spectrometry(GC-MS). The results of this paper are shown as follows:1) Nine PBDEs and eight aBFRs were detected in four bays(Dalian Bay, Sishili Bay, Taozi Bay, Jiaozhou Bay, and two rivers discharging into Jiaohzou Bay) of Yellow Sea. DBDPE a nd BDE209 are two dominant BFRs with the highest detection frequencies and concentrations. The concentrations of DBDPE were ranged from 130 to 49940 pg/g dw and 160 to 39650 pg/g dw in river and marine samples, respectively, and ha ve exceeded those of BDE209(50.0 to 7820 pg/g dw and nd to 1020 pg/g dw in river and marine samples, respectively) in the four bay areas. The concentrations of DBDPE and BDE209 are higher in the sites around the sewage outlets and river estuaries than other stations, and thus WWTPs and river might be the sources of Dalian Bay and Jiaozhou Bay. Furthermore, transport from Laizhou Bay around the BFR manufacturing base by coastal currents is the major source of BFRs in Taozi Bay and Sishili Bay. TBE, TBB and TBPH are not detected in bay sediments, whereas ∑PBDEs and ∑a BFR4 are detected at low concentrations in all sediments. They are probably attributable to a combination of factors such as low regional usage of these products, atmospheric deposition, coastal currents transportation, and degradation processes for higher BDE congeners.2) The detection of DBDPE, BDE209, ∑PBDEs, ∑aBFR4 and DPs in the sediments of the Bohai Sea are all more than 69.0%, which means that HFRs are widely existed in this area. DBDPE and BDE209 are both the main HFRs in the rivers and marine sediments from the Bohai Sea, which is consisted with those in the bays of the Yellow Sea. Mean concentrations of DBDPE, BDE209, ∑PBDEs, ∑a BFR7 and DPs in marine samples are 2560 pg/g dw, 250 pg/g dw, 16.6 pg/g dw, 33.4 pg/g dw and 19.7 pg/g dw, respectively. This paper divided Bohai Sea into 5 parts, including the Dalian Bay, the Bohai Sea, the Laizhou Bay, the Central Bohai Sea and the Bohai Strait. The detection frequencies and concentrations of HFRs in rivers(around the Bohai Sea) are higher than those in marine samples, and the highest concentrations of DBDPE and BDE209 are found in the Mi river which is closed to the BFRs manufacturing area. High levels of DBDPE and BDE209 have been found both in the riverine and marine sediment samples of Laizhou Bay. This indicates that BFRs factories influence the concentrations of BFRs in marine and rivers samples. However, DBDPE and BDE209 are both at low concentrations in the Bohai Bay and Dalian Bay, as well as low concentrations of those two BFRs are determined in rivers around this bay. These results show that rivers are the significant source of DBDPE and BDE209. The good correlation between DBDPE and BDE209 indicates that these two BFRs shares common sources. Good correlations between DBDPE with TOC and MD in marine are found, but poor correlations were found in rivers, which is the same for BDE209. Meanwhile, poor correlations were found between TOC and MD with the other HFRs in all sediments. These results show that HFRs of rivers are ascribed to the input of point source or no-point source. The distributions of DPs are contrary to those of DBDPE, so the source of DPs may not be from rivers. The major sources of ∑PBDEs, ∑aBFR7 and DPs are probably attributable to a combination of factors. |
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