The joint toxicity of Penta-BDE(Pe-BDE)and heavy metals including cadmium and copper on Daphnia magna(D.magna)was evaluated on the basis of determining the 48 h survival,antioxidative enzyme responses,and lipid peroxi...The joint toxicity of Penta-BDE(Pe-BDE)and heavy metals including cadmium and copper on Daphnia magna(D.magna)was evaluated on the basis of determining the 48 h survival,antioxidative enzyme responses,and lipid peroxidation.The response was classified as additive,greater than additive,or less than additive by comparing the measured“toxic units,TU”with one.Based on the survival of D.magna,less-than-additive interactions were found in most of mixtures treatments.This may be attributed to the different toxicity mechanism between Pe-BDE and metals.Cu and Cd played a greater role in toxicity than what Pe-BDE did.As for the superoxide dismutase(SOD)and catalase(CAT)activity,most response was less than additive.For the glutathione S-transferases(GST)activity,most of the greater-thanadditive responses were found in the Cu plus Pe-BDE treatments,but the additive responses occurred in Cd plus Pe-BDE treatments and binary metal treatments.For lipid peroxide levels,which were measured as malondialdehyde(MDA)levels,less-than-additive response occurred in the 50%Cd plus 50%Cu and ternary mixture treatments.Results suggested that Pe-BDE,Cd,and Cu could induce different patterns of antioxidant enzyme responses,such as antioxidant/prooxidant responses,depending on their capability to produce reactive oxygen species and antioxidant enzymes to detoxify them.展开更多
Decabromodiphenyl ether(BDE209) is poorly absorbed by mammals,and little information is available on the toxicokinetics of BDE209 and its metabolites in fish.In the present study,rainbow trout(Oncorhynchus mykiss) wer...Decabromodiphenyl ether(BDE209) is poorly absorbed by mammals,and little information is available on the toxicokinetics of BDE209 and its metabolites in fish.In the present study,rainbow trout(Oncorhynchus mykiss) were administered to 100 ng/g and 500 ng/g body wet weight of BDE209 via a single intraperitoneal injection and parent BDE209 and its metabolites were sequentially monitored for 28 days.The results showed that toxicokinetic profiles of BDE209 could be described by the one-compartment model.In the higher dose group(500 ng/g wet weight),the calculated half-life(t1/2) and elimination rate(ke) were 17.7 d and 0.039/d in the liver,and 100.3 d and 0.007/d in the muscle,respectively.Three major methoxylated brominated diphenyl ethers(MeO-BDEs) were detected with 2,2',4,4'-tetrabromo-5-methoxydiphenyl ether(5-MeO-BDE47) being detected in all tissue samples.There was no significant temporal change of 5-MeO-BDE47 concentration in the muscle,whereas an exponential increase was observed in the liver.Therefore,the metabolism rate of BDE209 depended on the administered dose.BDE209 was hardly accumulated in the muscle of rainbow trout,while the liver was a primary metabolic organ.MeO-BDEs were formed via metabolism of BDE209,which probably played a significant role in fish toxicology as a potential indicator.展开更多
Concentrations of polybrominated diphenyl ethers(PBDEs),hexabromocyclododecane(HBCDD),tetrabromobisphenol-A(TBBPA)and two potential replacements decabromodiphenylethane(DBDPE)and 1,2-bis(2,4,6-tribromophenoxy)ethane(B...Concentrations of polybrominated diphenyl ethers(PBDEs),hexabromocyclododecane(HBCDD),tetrabromobisphenol-A(TBBPA)and two potential replacements decabromodiphenylethane(DBDPE)and 1,2-bis(2,4,6-tribromophenoxy)ethane(BTBPE)were measured in dust samples collected from 14 homes across Birmingham(UK).Concentrations were compared with those from the same city in previous studies to ascertain any temporal changes and to assess the effects of legislative restrictions.The average PHBCDDs concentration(46,000 ng/g;median=280 ng/g)included the highest dust concentration recorded globally(570,000 ng/g).This is despite the listing of HBCDD under the Stockholm Convention in 2013,demonstrating that decreases in indoor contamination will likely be slow as existing sources are gradually discarded.In contrast,concentrations of BDE-47(mean=5.7 ng/g;median=0.93 ng/g)and BDE-99(mean=11 ng/g;median=2.9 ng/g)were significantly lower than in all previous(p<0.01)studies in the same city since 2006,suggesting restrictions on the Penta-BDE formulation have been effective.The average BDE-209 concentration(4800 ng/g;median=1600 ng/g)is lower than the peak average concentration,which was observed in 2007(280,000 ng/g),however this is not a significant decline,probably due to the later imposition of Deca-BDE restrictions compared to those on Penta-BDE.Decreases in PBDE concentrations have coincided with a significant(p<0.01)increase in DBDPE concentrations(average=1500 ng/g;median=660 ng/g)since 2014,suggesting its use as a replacement flame retardant for Deca-BDE.While no significant change was detected for BTBPE(average 11 ng/g;median=0.84 ng/g in this study);concentrations of TBBPA(average=34 ng/g;median=35 ng/g)were significantly lower(p<0.05)than in 2007(average 62 ng/g).The decreases observed in PBDE concentrations,demonstrates that legislation has been effective in reducing the commercial use of PBDEs,however this has coincided with increases of alternative flame retardants such as DBDPE.展开更多
Polybrominated diphenyl ethers(PBDEs)have been used as flame retardants in various building materials,plastic and other polymers,airplanes,electronics,etc.All or some of their congeners have been already banned in man...Polybrominated diphenyl ethers(PBDEs)have been used as flame retardants in various building materials,plastic and other polymers,airplanes,electronics,etc.All or some of their congeners have been already banned in many countries,due to their persistency and adverse health effects.In this study,we are focusing on e-wastes as a source of emission of PBDEs in ambient air during reclamation processes.The ambient air particulate matter(PM)samples were collected at and near an e-waste reclamation site in Bangkok,Thailand.Results showed the presence of various homologues,viz:tri-,tetra-,penta-,hexa-,and hepta-PBDEs in both PM2.5 and total suspended particle(TSP)samples.The comparison of samples as a function of distance from the reclamation site indicated elevated levels of PBDEs in close proximity to the e-waste site.Interestingly,a shift in the congener pattern was observed with lower brominated PBDEs being more prevalent in nearby off-site samples as compared to the PM collected at the e-waste site.The total penta-PBDEs concentration is almost double in the e-waste site PM2.5 compared to the control site samples.For TSP,tetra,penta,and hepta-PBDEs congeners are at higher concentrations at the e-waste sites and its vicinity compared to reference sites.Overall,a clear trend can be observed indicating a debromination of PBDEs to more toxic tri and tetra congeners during the reclamation process and PBDEs are being translocated from treated materials to ambient air PM.BDE 30 is uniquely detected in our studies as a dominant final debromination product,that can be used as a marker of thermal e-waste activity.This work indicates potential hazards related to the reclamation of e-wastes and remediation of sites containing PBDEs.In particular,thermal treatment methods can lead to congener transformation and increased emissions of more toxic lower brominated congeners.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.20777040)the Ministry of Education,People’s Republic of China as a cultivation fund of the Key Scientific and Technical Innovation Project(No.707011)+1 种基金the specialized research fund for doctoral program of higher education(No.20070055031)the program of New Century Excellent Talent.
文摘The joint toxicity of Penta-BDE(Pe-BDE)and heavy metals including cadmium and copper on Daphnia magna(D.magna)was evaluated on the basis of determining the 48 h survival,antioxidative enzyme responses,and lipid peroxidation.The response was classified as additive,greater than additive,or less than additive by comparing the measured“toxic units,TU”with one.Based on the survival of D.magna,less-than-additive interactions were found in most of mixtures treatments.This may be attributed to the different toxicity mechanism between Pe-BDE and metals.Cu and Cd played a greater role in toxicity than what Pe-BDE did.As for the superoxide dismutase(SOD)and catalase(CAT)activity,most response was less than additive.For the glutathione S-transferases(GST)activity,most of the greater-thanadditive responses were found in the Cu plus Pe-BDE treatments,but the additive responses occurred in Cd plus Pe-BDE treatments and binary metal treatments.For lipid peroxide levels,which were measured as malondialdehyde(MDA)levels,less-than-additive response occurred in the 50%Cd plus 50%Cu and ternary mixture treatments.Results suggested that Pe-BDE,Cd,and Cu could induce different patterns of antioxidant enzyme responses,such as antioxidant/prooxidant responses,depending on their capability to produce reactive oxygen species and antioxidant enzymes to detoxify them.
基金supported by the National Basic Research Program of China (2009CB421605)the National Natural Science Foundation of China (20737003 & 20877089)
文摘Decabromodiphenyl ether(BDE209) is poorly absorbed by mammals,and little information is available on the toxicokinetics of BDE209 and its metabolites in fish.In the present study,rainbow trout(Oncorhynchus mykiss) were administered to 100 ng/g and 500 ng/g body wet weight of BDE209 via a single intraperitoneal injection and parent BDE209 and its metabolites were sequentially monitored for 28 days.The results showed that toxicokinetic profiles of BDE209 could be described by the one-compartment model.In the higher dose group(500 ng/g wet weight),the calculated half-life(t1/2) and elimination rate(ke) were 17.7 d and 0.039/d in the liver,and 100.3 d and 0.007/d in the muscle,respectively.Three major methoxylated brominated diphenyl ethers(MeO-BDEs) were detected with 2,2',4,4'-tetrabromo-5-methoxydiphenyl ether(5-MeO-BDE47) being detected in all tissue samples.There was no significant temporal change of 5-MeO-BDE47 concentration in the muscle,whereas an exponential increase was observed in the liver.Therefore,the metabolism rate of BDE209 depended on the administered dose.BDE209 was hardly accumulated in the muscle of rainbow trout,while the liver was a primary metabolic organ.MeO-BDEs were formed via metabolism of BDE209,which probably played a significant role in fish toxicology as a potential indicator.
基金Royal Golden Jubilee Ph.D.Program(RGJ-Ph.D.Program)scholarship of Thailand Research Fund(PHD/0129/2559)to carry out this work.
文摘Concentrations of polybrominated diphenyl ethers(PBDEs),hexabromocyclododecane(HBCDD),tetrabromobisphenol-A(TBBPA)and two potential replacements decabromodiphenylethane(DBDPE)and 1,2-bis(2,4,6-tribromophenoxy)ethane(BTBPE)were measured in dust samples collected from 14 homes across Birmingham(UK).Concentrations were compared with those from the same city in previous studies to ascertain any temporal changes and to assess the effects of legislative restrictions.The average PHBCDDs concentration(46,000 ng/g;median=280 ng/g)included the highest dust concentration recorded globally(570,000 ng/g).This is despite the listing of HBCDD under the Stockholm Convention in 2013,demonstrating that decreases in indoor contamination will likely be slow as existing sources are gradually discarded.In contrast,concentrations of BDE-47(mean=5.7 ng/g;median=0.93 ng/g)and BDE-99(mean=11 ng/g;median=2.9 ng/g)were significantly lower than in all previous(p<0.01)studies in the same city since 2006,suggesting restrictions on the Penta-BDE formulation have been effective.The average BDE-209 concentration(4800 ng/g;median=1600 ng/g)is lower than the peak average concentration,which was observed in 2007(280,000 ng/g),however this is not a significant decline,probably due to the later imposition of Deca-BDE restrictions compared to those on Penta-BDE.Decreases in PBDE concentrations have coincided with a significant(p<0.01)increase in DBDPE concentrations(average=1500 ng/g;median=660 ng/g)since 2014,suggesting its use as a replacement flame retardant for Deca-BDE.While no significant change was detected for BTBPE(average 11 ng/g;median=0.84 ng/g in this study);concentrations of TBBPA(average=34 ng/g;median=35 ng/g)were significantly lower(p<0.05)than in 2007(average 62 ng/g).The decreases observed in PBDE concentrations,demonstrates that legislation has been effective in reducing the commercial use of PBDEs,however this has coincided with increases of alternative flame retardants such as DBDPE.
基金supported by National Institute of Environmental Health Sciences Superfund Research Program,Grant number P42ES013648.
文摘Polybrominated diphenyl ethers(PBDEs)have been used as flame retardants in various building materials,plastic and other polymers,airplanes,electronics,etc.All or some of their congeners have been already banned in many countries,due to their persistency and adverse health effects.In this study,we are focusing on e-wastes as a source of emission of PBDEs in ambient air during reclamation processes.The ambient air particulate matter(PM)samples were collected at and near an e-waste reclamation site in Bangkok,Thailand.Results showed the presence of various homologues,viz:tri-,tetra-,penta-,hexa-,and hepta-PBDEs in both PM2.5 and total suspended particle(TSP)samples.The comparison of samples as a function of distance from the reclamation site indicated elevated levels of PBDEs in close proximity to the e-waste site.Interestingly,a shift in the congener pattern was observed with lower brominated PBDEs being more prevalent in nearby off-site samples as compared to the PM collected at the e-waste site.The total penta-PBDEs concentration is almost double in the e-waste site PM2.5 compared to the control site samples.For TSP,tetra,penta,and hepta-PBDEs congeners are at higher concentrations at the e-waste sites and its vicinity compared to reference sites.Overall,a clear trend can be observed indicating a debromination of PBDEs to more toxic tri and tetra congeners during the reclamation process and PBDEs are being translocated from treated materials to ambient air PM.BDE 30 is uniquely detected in our studies as a dominant final debromination product,that can be used as a marker of thermal e-waste activity.This work indicates potential hazards related to the reclamation of e-wastes and remediation of sites containing PBDEs.In particular,thermal treatment methods can lead to congener transformation and increased emissions of more toxic lower brominated congeners.
