Hexabromocyclododecane （HBCD） and tetrabromobisphenol A （TBBPA） are two kinds of brominated flame retardants and widely present in the environment and biota. The levels, spatial distributions and mass inventories ...Hexabromocyclododecane （HBCD） and tetrabromobisphenol A （TBBPA） are two kinds of brominated flame retardants and widely present in the environment and biota. The levels, spatial distributions and mass inventories of HBCD and TBBPA were investigated in sediments and paddy soils from the Liaohe River Basin in northeast China. The concentrations of ∑HBCD and TBBPA were in the range of not detected （nd） to 4.02 ng/g dry weight （dw） and 0.03 to 4.06 ng/g dw, respectively, y-HBCD was dominated in sediments, while the abundance of a-HBCD was relatively high in paddy soils. The spatial distributions of HBCD and TBBPA in surface sediments and paddy soils indicated that the local point-input was their major source. The significant correlation between total organic carbon （TOC） contents and the HBCD levels suggested that TOC content also exerted an influence on the distribution of HBCD in sediments. Meanwhile, it was found that the irrigation with fiver water was not the major transportation pathway of HBCD and TBBPA in paddy soils. Based on the study, it was estimated that there were about 1.67 tons HBCD and 2.20 tons TBBPA deposited into sediments of the Liaohe River system every year. The total mass inventories of HBCD and TBBPA in sediments were far higher than that in paddy soils.展开更多
To investigate the accumulation and phytotoxicity of technical hexabromocyclododecane（HBCD）in maize,young seedlings were exposed to solutions of technical HBCD at different concentrations.The uptake kinetics showed ...To investigate the accumulation and phytotoxicity of technical hexabromocyclododecane（HBCD）in maize,young seedlings were exposed to solutions of technical HBCD at different concentrations.The uptake kinetics showed that the HBCD concentration reached an apparent equilibrium within 96 hr,and the accumulation was much higher in roots than in shoots.HBCD accumulation in maize had a positive linear correlation with the exposure concentration.The accumulation of different diastereoisomers followed the orderγ-HBCD〉β-HBCD〉α-HBCD.Compared with their proportions in the technical HBCD exposure solution,the diastereoisomer contribution increased forβ-HBCD and decreased forγ-HBCD in both maize roots and shoots with exposure time,whereas the contribution ofα-HBCD increased in roots and decreased in shoots throughout the experimental period.These results suggest the diastereomer-specific accumulation and translocation of HBCD in maize.Inhibitory effects of HBCD on the early development of maize followed the order of germination rate〉root biomass≥root elongation〉shoot biomass≥shoot elongation.Hydroxyl radical（OH）and histone H2AX phosphorylation（γ-H2AX）were induced in maize by HBCD exposure,indicative of the generation of oxidative stress and DNA double-strand breaks in maize.An OH scavenger inhibited the expression ofγ-H2AX foci in both maize roots and shoots,which suggests the involvement of OH generation in the HBCD-induced DNA damage.The results of this study will offer useful information for a more comprehensive assessment of the environmental behavior and toxicity of technical HBCD.展开更多
Hexabromocyclododecanes（HBCDs）,a new type of persistent organic pollutants widely used as brominated flame retardants,have attracted wide attention due to their increasing level and toxicity. A method based on high-...Hexabromocyclododecanes（HBCDs）,a new type of persistent organic pollutants widely used as brominated flame retardants,have attracted wide attention due to their increasing level and toxicity. A method based on high-performance liquid chromatography mass spectrometry（HPLC–MS–MS）in electrospray ionization mode has been developed by optimization of various parameters,which effectively improved the separation degree and responsive intensity of α-,β-and γ-HBCD isomers. The concentrations and distribution profiles of three HBCD isomers were investigated in sediments from the Haihe River in China.It was observed that the concentrations of HBCDs varied in the range of 0.4–58.82 ng/g,showing a decreasing trend along the flow direction,possibly due to attenuation and biodegradation along the flow direction of the Haihe River. The distribution profile of α-,β-,γ-HBCD was 7.91%–88.6%,0–91.47%,and 0.62%–42.83%,respectively. Interestingly,α-HBCD dominated in most sample sites. This was different from the distribution profile in commercial industrial products,which might be attributed to the inter-transformation and different degradation rates of the three HBCD isomers. The potential ecological risk of HBCDs in sediment was characterized under the two-tiered procedure of the European Medicines Evaluation Agency for environmental risk assessment. Although the HBCDs in the selected section of the Haihe River presented ＂no risk＂ in the sediment compartment,its risk in sediment cannot be neglected since sediment is one of the important sinks and reservoirs of pollutants.展开更多
基金supported by the National Natural Science Foundation of China (nos. 21205117, 21277139)the Special Fund for Agro-scientific Research in the Public Interest (no. 201503108)+1 种基金the Hi-Tech Research and Development Program (863) of China (no. 2013AA065203)the National Basic Research Program (973) of China (no. 2015CB453100)
文摘Hexabromocyclododecane （HBCD） and tetrabromobisphenol A （TBBPA） are two kinds of brominated flame retardants and widely present in the environment and biota. The levels, spatial distributions and mass inventories of HBCD and TBBPA were investigated in sediments and paddy soils from the Liaohe River Basin in northeast China. The concentrations of ∑HBCD and TBBPA were in the range of not detected （nd） to 4.02 ng/g dry weight （dw） and 0.03 to 4.06 ng/g dw, respectively, y-HBCD was dominated in sediments, while the abundance of a-HBCD was relatively high in paddy soils. The spatial distributions of HBCD and TBBPA in surface sediments and paddy soils indicated that the local point-input was their major source. The significant correlation between total organic carbon （TOC） contents and the HBCD levels suggested that TOC content also exerted an influence on the distribution of HBCD in sediments. Meanwhile, it was found that the irrigation with fiver water was not the major transportation pathway of HBCD and TBBPA in paddy soils. Based on the study, it was estimated that there were about 1.67 tons HBCD and 2.20 tons TBBPA deposited into sediments of the Liaohe River system every year. The total mass inventories of HBCD and TBBPA in sediments were far higher than that in paddy soils.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB14020202)the National Natural Science Foundation of China(Nos.21321004 and 21407041)
文摘To investigate the accumulation and phytotoxicity of technical hexabromocyclododecane（HBCD）in maize,young seedlings were exposed to solutions of technical HBCD at different concentrations.The uptake kinetics showed that the HBCD concentration reached an apparent equilibrium within 96 hr,and the accumulation was much higher in roots than in shoots.HBCD accumulation in maize had a positive linear correlation with the exposure concentration.The accumulation of different diastereoisomers followed the orderγ-HBCD〉β-HBCD〉α-HBCD.Compared with their proportions in the technical HBCD exposure solution,the diastereoisomer contribution increased forβ-HBCD and decreased forγ-HBCD in both maize roots and shoots with exposure time,whereas the contribution ofα-HBCD increased in roots and decreased in shoots throughout the experimental period.These results suggest the diastereomer-specific accumulation and translocation of HBCD in maize.Inhibitory effects of HBCD on the early development of maize followed the order of germination rate〉root biomass≥root elongation〉shoot biomass≥shoot elongation.Hydroxyl radical（OH）and histone H2AX phosphorylation（γ-H2AX）were induced in maize by HBCD exposure,indicative of the generation of oxidative stress and DNA double-strand breaks in maize.An OH scavenger inhibited the expression ofγ-H2AX foci in both maize roots and shoots,which suggests the involvement of OH generation in the HBCD-induced DNA damage.The results of this study will offer useful information for a more comprehensive assessment of the environmental behavior and toxicity of technical HBCD.
基金supported by the National Basic Research Program(973) of China(No.2015CB453103)National Key Research and Development Plan(No.2016YFC0202500)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB14020102)the National Natural Science Foundation of China(Nos.21677163,21377147,and 21321004)
文摘Hexabromocyclododecanes（HBCDs）,a new type of persistent organic pollutants widely used as brominated flame retardants,have attracted wide attention due to their increasing level and toxicity. A method based on high-performance liquid chromatography mass spectrometry（HPLC–MS–MS）in electrospray ionization mode has been developed by optimization of various parameters,which effectively improved the separation degree and responsive intensity of α-,β-and γ-HBCD isomers. The concentrations and distribution profiles of three HBCD isomers were investigated in sediments from the Haihe River in China.It was observed that the concentrations of HBCDs varied in the range of 0.4–58.82 ng/g,showing a decreasing trend along the flow direction,possibly due to attenuation and biodegradation along the flow direction of the Haihe River. The distribution profile of α-,β-,γ-HBCD was 7.91%–88.6%,0–91.47%,and 0.62%–42.83%,respectively. Interestingly,α-HBCD dominated in most sample sites. This was different from the distribution profile in commercial industrial products,which might be attributed to the inter-transformation and different degradation rates of the three HBCD isomers. The potential ecological risk of HBCDs in sediment was characterized under the two-tiered procedure of the European Medicines Evaluation Agency for environmental risk assessment. Although the HBCDs in the selected section of the Haihe River presented ＂no risk＂ in the sediment compartment,its risk in sediment cannot be neglected since sediment is one of the important sinks and reservoirs of pollutants.
