Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous environmental contaminants of growing concern due to their potential ecological and human health risks.This study presents a comprehensive assessment of PAHs contam...Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous environmental contaminants of growing concern due to their potential ecological and human health risks.This study presents a comprehensive assessment of PAHs contamination in the surface sediments of Burullus Lake,a vital and second largest delta lake in Egypt.The aim was to evaluate the eco-toxicity and potential health risks associated with the presence of these compounds.Surface seven sediment samples were collected from various drains in the southern part of Burullus Lake.Soxhlet extraction method was employed to extract PAHs(16PAHs)from the sediment sample.Analytically,target compounds were located using HPLC.The results showed that samples contained PAHs levels ranging from 0.038×10^(-6)to 0.459×10^(-6),which is considered heavily polluted by the European standard for PAHs pollution.Additionally,there was no apparent source of PAHs in the ElKhashah drain or the Brinbal Canal,as HPLC found none of the compounds.The most prevalent compound in sediment samples along the study area was fluoranthene.The diagnostic indices in the present study indicated that the hydrocarbons in the region originated from pyrolytic and man-made sources along the drains of Burullus Lake.The principal component analysis(PCA)and diagnostic ratios revealed that coal combustion and pyrolytic sources were responsible for the PAHs contamination in the surface sediments.The non-carcinogenic risk(HI),which is the product of the HQs for the adult and child populations,respectively,was calculated.HI values under 1,therefore,demonstrated that they had no carcinogenic effects on human health.TEQs and MEQs in the sediments of Burullus Lake do not have a cancer-causing impact on people.For the safety of nearby wildlife,aquatic life,and people,all activities that raise petroleum hydrocarbon levels in Burullus Lake must be adequately regulated and controlled.According to the ecological risk assessment,there is little chance that PAHs will be found in the sediments of Burullus Lake.This study underscores the urgent need for effective pollution control measures and regular monitoring of PAHs levels in Burullus Lake sediments to protect the aquatic ecosystem and public health.It also highlights the importance of considering eco-toxicity and human health risks in integrated risk assessments of PAHs-contaminated environments.展开更多
This study is concerned with the effects of di (2-ethylhexyl) phthalate (DEHP) on two kinds of duckweeds (Spirodela polyrhiza and Lemna minor).The results indicate that DEHP has aquatic toxicity to Spirodela pol...This study is concerned with the effects of di (2-ethylhexyl) phthalate (DEHP) on two kinds of duckweeds (Spirodela polyrhiza and Lemna minor).The results indicate that DEHP has aquatic toxicity to Spirodela polyrhiza at 0.4 mg/L and to Lemna minor at over 0.1 mg/L by changing their physiologic-biochemical characteristics.The contents of duckweed chlorophyll and soluble protein decrease with increasing DEHP concentration after 7 d of exposure.DEHP shows the stimulating role in catalase (CAT) and superoxide dismutase (SOD) systems at relative low levels.At 0.01 mg/L and 0.005 mg/L,SOD activities of Spirodela polyrhiza and Lemna minor reach their peak values respectively,while CAT activity reaches its maximum value at 0.05 mg/L and 0.01 mg/L.When DEHP levels are too high,the protection enzyme system would be destroyed and plant growth is inhibited.The analysis of malondialdehyde (MDA) and Fourier transform infrared spectroscopy manifest that DEHP could affect the tested duckweeds by destroying its cell membranes,and Spirodela polyrhiza is more resistant to DEHP exposure than Lemna minor.展开更多
In our previous study,we prepared the granules by embedding artemisinin into alginate-chitosan using microcapsule technology.These granules can release artemisinin sustainably and have a strong inhibitory effect on th...In our previous study,we prepared the granules by embedding artemisinin into alginate-chitosan using microcapsule technology.These granules can release artemisinin sustainably and have a strong inhibitory effect on the growth of both single Microcystis aeruginosa and mixed algae.To safely and effectively use artemisinin sustained-release granules to control algal blooms,the ecotoxicity was studied by assessing their acute and chronic toxicity to Daphnia magna(D.magna)and Danio rerio(D.rerio),along with their antioxidant activities.The results showed that the 48-h median effective concentration(EC50)of pure artemisinin to D.magna was 24.54 mg/L and the 96-h median lethal concentration(LC50)of pure artemisinin to D.rerio was 68.08 mg/L.Both values were classified as intermediate toxicity according to the Organization for Economic Co-operation and Development(OECD).The optimal algae inhibitory concentration of artemisinin sustained-release granules(1 g/L)had low acute toxicity to both D.magna and D.rerio.The sustained-release granules had higher chronic toxicity to D.magna than to D.rerio.Partial indices of D.magna were inhibited by granules when the concentrations were larger than 0.1 g/L.Low granule concentration had an inductive effect on antioxidant enzyme activities in D.magna and D.rerio.With the increase of the exposure concentration and time,the enzyme activity presented a trend of first increasing and then decreasing,and the overall changes were significant.The change trend and range of enzyme activity indicated that the granules could cause serious oxidative stress to D.magna and D.rerio,and the changes were consistent with the results of toxicity experimentation.展开更多
Phenylthio-carboxylates were computed at the B3LYP/6-31G* level with DFT method. Based on linear solvation energy theory, the structural parameters were firstly taken as theoretical descriptors, and the correspondin...Phenylthio-carboxylates were computed at the B3LYP/6-31G* level with DFT method. Based on linear solvation energy theory, the structural parameters were firstly taken as theoretical descriptors, and the corresponding linear solvation energy relationship (LSER) equation (r = 0.8989) to the toxicity of photobacterium phosphoreum (–lgEC50) was thus obtained. Then the structural and thermodynamic parameters were taken as theoretical descriptors, and as a result the other corresponding correlation equation (r = 0.9274) relating to –lgEC50 was provided. The two equations achieved in this work by B3LYP/6-31G* are both more advantageous than that from AM1.展开更多
Perfluorobutanesulfonate(PFBS)is an emerging pollutant capable of potently disrupting the sex and thyroid endocrine systems of teleosts.However,the hypoxic and temporal variation in PFBS endocrine disrupting toxicity ...Perfluorobutanesulfonate(PFBS)is an emerging pollutant capable of potently disrupting the sex and thyroid endocrine systems of teleosts.However,the hypoxic and temporal variation in PFBS endocrine disrupting toxicity remain largely unknown.In the present study,adult marine medaka were exposed to environmentally realistic concentrations of PFBS(0 and 10μg/L)under normoxia or hypoxia conditions for 7 days,aiming to explore the interactive behavior between PFBS and hypoxia.In addition,PFBS singular exposure was extended till 21days under normoxia to elucidate the time-course progression in PFBS toxicity.The results showed that hypoxia inhibited the growth and caused the suspension of egg spawn regardless of PFBS exposure.With regard to the sex endocrine system,7-day PFBS exposure led to an acute stimulation of transcriptional profiles in females,which,subsequently,recovered after the 21-day exposure.The potency of hypoxia to disturb the sex hormones was much stronger than PFBS.A remarkable increase in estradiol concentration was noted in medaka blood after hypoxia exposure.Changes in sex endocrinology of coexposed fish were largely determined by hypoxia,which drove the formation of an estrogenic environment.PFBS further enhanced the endocrine disrupting effects of hypoxia.However,the hepatic synthesis of vitellogenin and choriogenin,two commonly used sensitive biomarkers of estrogenic activity,failed to initiate in response to the estrogen stimulus.Compared to sex endocrine system,disturbances in thyroidal axis by PFBS or hypoxia were relatively mild.Overall,the present findings will advance our toxicological understanding about PFBS pollutant under the interference of hypoxia.展开更多
Based on the three-dimensional structures of the compounds,the structures of 48 ester compounds were expressed parametrically.Through multiple linear regression and partial least-squares regression,the relationship mo...Based on the three-dimensional structures of the compounds,the structures of 48 ester compounds were expressed parametrically.Through multiple linear regression and partial least-squares regression,the relationship models between ester compound structures and aquatic toxicity log(1/IGC50)were established.The correlation coefficients(R2)of the models were 0.9974 and 0.9940,and the standard deviations(SD)were 0.0469 and 0.0646,respectively.The stability of the models was evaluated by the leave-one-out internal cross-test.The correlation coefficients(RCV2)of the models of interactive tests were 0.9939 and 0.8952,and the standard deviation(SDCV)was 0.0715 and 0.0925,respectively.The external samples were used to test the predictive ability of the models,and the correlation coefficients(Rtest2)of the external predictions were 0.9955 and 0.9955,and the standard deviations(SDtest)were 0.0720 and 0.0716,respectively.The molecular structure descriptors could successfully represent the structural characteristics of the compounds,and the built models had good fitting effects,strong stability and high prediction accuracy.The present study has a good reference value for the study of the structure-toxicity relationship of toxic compounds in the environment.展开更多
Widespread application of poly-and per-fluoroalkyl substances(PFAS)has resulted in some substances being ubiquitous in environmental matrices.That and their resistance to degradation have allowed them to accumulate in...Widespread application of poly-and per-fluoroalkyl substances(PFAS)has resulted in some substances being ubiquitous in environmental matrices.That and their resistance to degradation have allowed them to accumulate in wildlife and humans with potential for toxic effects.While specific substances of concern have been phased-out or banned,other PFAS that are emerging as alternative substances are still produced and are being released into the environment.This review focuses on describing three emerging,replacement PFAS:perfluoroethylcyclohexane sulphonate(PFECHS),6:2 chlorinated polyfluoroalkyl ether sulfonate(6:2 Cl-PFAES),and hexafluoropropylene oxide dimer acid(HFPO-DA).By summarizing their physicochemical properties,environmental fate and transport,and toxic potencies in comparison to other PFAS compounds,this review offers insight into the viabilities of these chemicals as replacement substances.Using the chemical scoring and ranking assessment model,the relative hazards,uncertainties,and data gaps for each chemical were quantified and related to perfluorooctane sulfonic acid(PFOS)and perfluorooctanoic acid(PFOA)based on their chemical and uncertainty scores.The substances were ranked PFOS>6:2 Cl-PFAES>PFOA>HFPO-DA>PFECHS according to their potential toxicity and PFECHS>HFPO-DA>6:2 Cl-PFAES>PFOS>PFOA according to their need for future research.Since future uses of PFAS remain uncertain in the face of governmental regulations and production bans,replacement PFAS will continue to emerge on the world market and in the environment,raising concerns about their general lack of information on mechanisms and toxic potencies.展开更多
The method of quantitative structure-activity relationships (QSARs) is one of necessa-ry approaches in hazard assessment of organic compounds. As a well-established QSARequation that can be used to predict biological ...The method of quantitative structure-activity relationships (QSARs) is one of necessa-ry approaches in hazard assessment of organic compounds. As a well-established QSARequation that can be used to predict biological activities (toxicity) of organic chemicals, it展开更多
小球藻、大型溞和斑马鱼作为水生生态系统中第一、二和三营养级,是构成简单水生食物链的重要成员,参与了水生生态系统中的物质循环和能量流动。为了阐明灭多威对食物链上处于不同生态位的水生生物的毒性效应,采用半静态水质接触急性试...小球藻、大型溞和斑马鱼作为水生生态系统中第一、二和三营养级,是构成简单水生食物链的重要成员,参与了水生生态系统中的物质循环和能量流动。为了阐明灭多威对食物链上处于不同生态位的水生生物的毒性效应,采用半静态水质接触急性试验法研究了灭多威对小球藻、大型溞、斑马鱼的急性毒性。结果表明,灭多威对小球藻的96 h EC_(50)为6.76 mg/L,对大型溞的24、48、96 h LC_(50)分别为57.37、22.23、12.58μg/L,对斑马鱼的24、48、96 h LC_(50)分别为8.64、5.00、2.12 mg/L。根据农药毒性分级标准,农药灭多威在普通小球藻、大型溞、斑马鱼上分别表现为中毒性、极高毒性和高毒性,在自然环境下极易导致藻、溞、鱼急性中毒死亡。灭多威对小球藻、大型溞、斑马鱼的安全浓度分别为0.676 mg/L、1.26μg/L、0.212 mg/L,其对上述水生生物的毒性大小顺序为:溞类>鱼类>藻类。展开更多
文摘Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous environmental contaminants of growing concern due to their potential ecological and human health risks.This study presents a comprehensive assessment of PAHs contamination in the surface sediments of Burullus Lake,a vital and second largest delta lake in Egypt.The aim was to evaluate the eco-toxicity and potential health risks associated with the presence of these compounds.Surface seven sediment samples were collected from various drains in the southern part of Burullus Lake.Soxhlet extraction method was employed to extract PAHs(16PAHs)from the sediment sample.Analytically,target compounds were located using HPLC.The results showed that samples contained PAHs levels ranging from 0.038×10^(-6)to 0.459×10^(-6),which is considered heavily polluted by the European standard for PAHs pollution.Additionally,there was no apparent source of PAHs in the ElKhashah drain or the Brinbal Canal,as HPLC found none of the compounds.The most prevalent compound in sediment samples along the study area was fluoranthene.The diagnostic indices in the present study indicated that the hydrocarbons in the region originated from pyrolytic and man-made sources along the drains of Burullus Lake.The principal component analysis(PCA)and diagnostic ratios revealed that coal combustion and pyrolytic sources were responsible for the PAHs contamination in the surface sediments.The non-carcinogenic risk(HI),which is the product of the HQs for the adult and child populations,respectively,was calculated.HI values under 1,therefore,demonstrated that they had no carcinogenic effects on human health.TEQs and MEQs in the sediments of Burullus Lake do not have a cancer-causing impact on people.For the safety of nearby wildlife,aquatic life,and people,all activities that raise petroleum hydrocarbon levels in Burullus Lake must be adequately regulated and controlled.According to the ecological risk assessment,there is little chance that PAHs will be found in the sediments of Burullus Lake.This study underscores the urgent need for effective pollution control measures and regular monitoring of PAHs levels in Burullus Lake sediments to protect the aquatic ecosystem and public health.It also highlights the importance of considering eco-toxicity and human health risks in integrated risk assessments of PAHs-contaminated environments.
基金supported by the National Natural Science Foundation of China (Grant Nos.40973073,40830744)the Shanghai Leading Academic Discipline Project (Grant No.S30109)+1 种基金the National Key Technology Research and Development Program in the 11th Five Year Plan of China (Grant Nos.2008BAC32B03,2009BAA24B04)the Natural Science Foundation of the Science and Technology Commission of Shanghai Municipality (Grant No.09ZR1411300)
文摘This study is concerned with the effects of di (2-ethylhexyl) phthalate (DEHP) on two kinds of duckweeds (Spirodela polyrhiza and Lemna minor).The results indicate that DEHP has aquatic toxicity to Spirodela polyrhiza at 0.4 mg/L and to Lemna minor at over 0.1 mg/L by changing their physiologic-biochemical characteristics.The contents of duckweed chlorophyll and soluble protein decrease with increasing DEHP concentration after 7 d of exposure.DEHP shows the stimulating role in catalase (CAT) and superoxide dismutase (SOD) systems at relative low levels.At 0.01 mg/L and 0.005 mg/L,SOD activities of Spirodela polyrhiza and Lemna minor reach their peak values respectively,while CAT activity reaches its maximum value at 0.05 mg/L and 0.01 mg/L.When DEHP levels are too high,the protection enzyme system would be destroyed and plant growth is inhibited.The analysis of malondialdehyde (MDA) and Fourier transform infrared spectroscopy manifest that DEHP could affect the tested duckweeds by destroying its cell membranes,and Spirodela polyrhiza is more resistant to DEHP exposure than Lemna minor.
基金supported by the National Natural Science Foundation of China(Grants No.91647206 and 51779079)the Program for Changjiang Scholars and Innovative Research Team at Hohai University(Grant No.IRT13061)+1 种基金the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP).
文摘In our previous study,we prepared the granules by embedding artemisinin into alginate-chitosan using microcapsule technology.These granules can release artemisinin sustainably and have a strong inhibitory effect on the growth of both single Microcystis aeruginosa and mixed algae.To safely and effectively use artemisinin sustained-release granules to control algal blooms,the ecotoxicity was studied by assessing their acute and chronic toxicity to Daphnia magna(D.magna)and Danio rerio(D.rerio),along with their antioxidant activities.The results showed that the 48-h median effective concentration(EC50)of pure artemisinin to D.magna was 24.54 mg/L and the 96-h median lethal concentration(LC50)of pure artemisinin to D.rerio was 68.08 mg/L.Both values were classified as intermediate toxicity according to the Organization for Economic Co-operation and Development(OECD).The optimal algae inhibitory concentration of artemisinin sustained-release granules(1 g/L)had low acute toxicity to both D.magna and D.rerio.The sustained-release granules had higher chronic toxicity to D.magna than to D.rerio.Partial indices of D.magna were inhibited by granules when the concentrations were larger than 0.1 g/L.Low granule concentration had an inductive effect on antioxidant enzyme activities in D.magna and D.rerio.With the increase of the exposure concentration and time,the enzyme activity presented a trend of first increasing and then decreasing,and the overall changes were significant.The change trend and range of enzyme activity indicated that the granules could cause serious oxidative stress to D.magna and D.rerio,and the changes were consistent with the results of toxicity experimentation.
基金This work was supported by the China Postdoctoral Science Foundation (No. 2003033486) National Natural Science Foundation of China (No. 20177008)
文摘Phenylthio-carboxylates were computed at the B3LYP/6-31G* level with DFT method. Based on linear solvation energy theory, the structural parameters were firstly taken as theoretical descriptors, and the corresponding linear solvation energy relationship (LSER) equation (r = 0.8989) to the toxicity of photobacterium phosphoreum (–lgEC50) was thus obtained. Then the structural and thermodynamic parameters were taken as theoretical descriptors, and as a result the other corresponding correlation equation (r = 0.9274) relating to –lgEC50 was provided. The two equations achieved in this work by B3LYP/6-31G* are both more advantageous than that from AM1.
基金supported by the National Natural Science Foundation of China (Nos.22006159 and 31971236)the Research Grants Council Theme-Based Research Scheme (No.T21-602/16-R)+1 种基金the Natural Science Foundation of Hubei Province,China (No.2021CFA086)the State Key Laboratory of Freshwater Ecology and Biotechnology (No.2022FBZ02)。
文摘Perfluorobutanesulfonate(PFBS)is an emerging pollutant capable of potently disrupting the sex and thyroid endocrine systems of teleosts.However,the hypoxic and temporal variation in PFBS endocrine disrupting toxicity remain largely unknown.In the present study,adult marine medaka were exposed to environmentally realistic concentrations of PFBS(0 and 10μg/L)under normoxia or hypoxia conditions for 7 days,aiming to explore the interactive behavior between PFBS and hypoxia.In addition,PFBS singular exposure was extended till 21days under normoxia to elucidate the time-course progression in PFBS toxicity.The results showed that hypoxia inhibited the growth and caused the suspension of egg spawn regardless of PFBS exposure.With regard to the sex endocrine system,7-day PFBS exposure led to an acute stimulation of transcriptional profiles in females,which,subsequently,recovered after the 21-day exposure.The potency of hypoxia to disturb the sex hormones was much stronger than PFBS.A remarkable increase in estradiol concentration was noted in medaka blood after hypoxia exposure.Changes in sex endocrinology of coexposed fish were largely determined by hypoxia,which drove the formation of an estrogenic environment.PFBS further enhanced the endocrine disrupting effects of hypoxia.However,the hepatic synthesis of vitellogenin and choriogenin,two commonly used sensitive biomarkers of estrogenic activity,failed to initiate in response to the estrogen stimulus.Compared to sex endocrine system,disturbances in thyroidal axis by PFBS or hypoxia were relatively mild.Overall,the present findings will advance our toxicological understanding about PFBS pollutant under the interference of hypoxia.
基金the Youth Foundation of Sichuan Provincial Department of Education(18ZB0323)。
文摘Based on the three-dimensional structures of the compounds,the structures of 48 ester compounds were expressed parametrically.Through multiple linear regression and partial least-squares regression,the relationship models between ester compound structures and aquatic toxicity log(1/IGC50)were established.The correlation coefficients(R2)of the models were 0.9974 and 0.9940,and the standard deviations(SD)were 0.0469 and 0.0646,respectively.The stability of the models was evaluated by the leave-one-out internal cross-test.The correlation coefficients(RCV2)of the models of interactive tests were 0.9939 and 0.8952,and the standard deviation(SDCV)was 0.0715 and 0.0925,respectively.The external samples were used to test the predictive ability of the models,and the correlation coefficients(Rtest2)of the external predictions were 0.9955 and 0.9955,and the standard deviations(SDtest)were 0.0720 and 0.0716,respectively.The molecular structure descriptors could successfully represent the structural characteristics of the compounds,and the built models had good fitting effects,strong stability and high prediction accuracy.The present study has a good reference value for the study of the structure-toxicity relationship of toxic compounds in the environment.
基金was supported by a Discovery Grant(Project#326415-07)from the Natural Sciences and Engineering Research Council of Canada.ProfGiesy was supported by the Canada Research Chair Program,and a Distinguished Visiting Professorship in the Department of Environmental Sciences,Baylor University in Waco,TX,USA.Prof.Brinkmann is currently a faculty member of the Global Water Futures(GWF)program,which was funded in part with financial support from the Canada First Research Excellence Funds(CFREF).
文摘Widespread application of poly-and per-fluoroalkyl substances(PFAS)has resulted in some substances being ubiquitous in environmental matrices.That and their resistance to degradation have allowed them to accumulate in wildlife and humans with potential for toxic effects.While specific substances of concern have been phased-out or banned,other PFAS that are emerging as alternative substances are still produced and are being released into the environment.This review focuses on describing three emerging,replacement PFAS:perfluoroethylcyclohexane sulphonate(PFECHS),6:2 chlorinated polyfluoroalkyl ether sulfonate(6:2 Cl-PFAES),and hexafluoropropylene oxide dimer acid(HFPO-DA).By summarizing their physicochemical properties,environmental fate and transport,and toxic potencies in comparison to other PFAS compounds,this review offers insight into the viabilities of these chemicals as replacement substances.Using the chemical scoring and ranking assessment model,the relative hazards,uncertainties,and data gaps for each chemical were quantified and related to perfluorooctane sulfonic acid(PFOS)and perfluorooctanoic acid(PFOA)based on their chemical and uncertainty scores.The substances were ranked PFOS>6:2 Cl-PFAES>PFOA>HFPO-DA>PFECHS according to their potential toxicity and PFECHS>HFPO-DA>6:2 Cl-PFAES>PFOS>PFOA according to their need for future research.Since future uses of PFAS remain uncertain in the face of governmental regulations and production bans,replacement PFAS will continue to emerge on the world market and in the environment,raising concerns about their general lack of information on mechanisms and toxic potencies.
文摘The method of quantitative structure-activity relationships (QSARs) is one of necessa-ry approaches in hazard assessment of organic compounds. As a well-established QSARequation that can be used to predict biological activities (toxicity) of organic chemicals, it
文摘小球藻、大型溞和斑马鱼作为水生生态系统中第一、二和三营养级,是构成简单水生食物链的重要成员,参与了水生生态系统中的物质循环和能量流动。为了阐明灭多威对食物链上处于不同生态位的水生生物的毒性效应,采用半静态水质接触急性试验法研究了灭多威对小球藻、大型溞、斑马鱼的急性毒性。结果表明,灭多威对小球藻的96 h EC_(50)为6.76 mg/L,对大型溞的24、48、96 h LC_(50)分别为57.37、22.23、12.58μg/L,对斑马鱼的24、48、96 h LC_(50)分别为8.64、5.00、2.12 mg/L。根据农药毒性分级标准,农药灭多威在普通小球藻、大型溞、斑马鱼上分别表现为中毒性、极高毒性和高毒性,在自然环境下极易导致藻、溞、鱼急性中毒死亡。灭多威对小球藻、大型溞、斑马鱼的安全浓度分别为0.676 mg/L、1.26μg/L、0.212 mg/L,其对上述水生生物的毒性大小顺序为:溞类>鱼类>藻类。