| 其他摘要 | Brominated flame retardants (BFRs) are bromine-containing organic compounds that prevent or suppress the spread of fires and are widely used in products such as textiles, furniture, building materials, and electronic appliances. With the acceleration of urbanization and industrialization, China has become the world's largest producer and user of BFRs. Jiangsu Province is an important BFRs production base in China, and the adjacent South Yellow Sea has received a large amount of land-based pollutants, posing a certain threat to the health of marine ecosystems. However, little attention has been paid to the pollution level of BFRs in coastal water, especially for the contamination of BFRs in the China Yellow Sea. In this study, BFRs had been selected as the target substance, and both surface and bottom seawater samples had been collected from the South Yellow Sea region in 2019-2020 to investigate the concentration levels, monomer composition, and spatial distribution of BFRs. The current BFRs pollution status and ecological risks in the South Yellow Sea were assessed. The inter-annual variation trend of BFRs in the water had been explored, and the possible sources and influencing factors of BFRs concentration in different regions had been analyzed. The results of this study have important scientific significance for the geochemical cycle of emerging contaminants in the region.
Surface and bottom seawater samples were collected in the spring and summer (June), summer (August), and autumn (October 2019 and and November 2020) in the southern Yellow Sea in 2019 and 2020. Fifteen types of BFRs in the seawater were analyzed using a gas chromatography-mass spectrometry (GC-MS) instrument. The results showed that: (1) BFRs were widely detected in the South Yellow Sea in 2019 and 2020. The concentration ranges of total PBDEs (∑8PBDEs) were n.d. - 91.86 pg L-1 (mean: 6.32 ± 12.99 pg L-1) and 2.35 - 672.91 pg L-1 (mean: 114.07 ± 155.29 pg L-1), respectively. The concentration ranges of total new brominated flame retardants (∑7NBFRs) were 0.13 - 93.85 pg L-1 (mean: 14.03 ± 17.90 pg L-1) and 4.22 - 450.97 pg L-1 (mean: 37.15 ± 68.58 pg L-1), respectively. (2) From the perspective of phase distribution, more than 90% of BFRs in seawater were enriched in the particulate phase. In terms of compound composition, decabromodiphenyl ether (BDE209) and decabromodiphenyl ethane (DBDPE) were the dominant compounds. (3) The seasonal variation of BFRs in the South Yellow Sea was significant. In 2019 and 2020, the concentration of BDE209 showed a characteristic trend of June > August > October and November, while the concentration of DBDPE showed a characteristic trend of June > August. The horizontal distribution generally showed a pattern of high concentration near the coast and low concentration far from the coast. River inputs were the main source of BFRs in the South Yellow Sea, and the southern Yellow Sea was significantly affected by the Yangtze River input. Rapid growth of phytoplankton in summer can lower the concentration of BFRs in surface water in some areas of the South Yellow Sea, while the presence of the Yellow Sea cold water mass results in lower BFRs levels in the central Yellow Sea. (4) Ecological risk of PBDEs in the water was estimated using the risk entropy method. The results showed that the risk of PBDEs in the South Yellow Sea was mainly due to BDE209, and overall, the ecological risk to aquatic organisms was low.
Through comparative analysis of the BFRs content in the South Yellow Sea seawater from 2016 to 2020, the results showed that the inter-annual variation of BFRs content in the South Yellow Sea seawater was large, and the variation trend of BFRs in the surface and bottom water was consistent. The fluctuation range of BFRs content from 2017 to 2019 was small, while the change from 2019 to 2020 was significant, which may be related to extreme weather events. The concentration of BDE209 decreased year by year in the northern part of the South Yellow Sea, while it increased year by year in the southern part, mainly due to the changes in BFRs production patterns in the north and the expansion of the Yangtze River diluted water influenced by the Yangtze River runoff and wind field. Compared with BDE209, the content of DBDPE in the northern seawaters of the South Yellow Sea (north of 34°N) remained relatively stable, indicating that besides river inputs, DBDPE also entered the South Yellow Sea water through other important pathways, such as atmospheric deposition. |
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