Aquatic toxicity of di (2-eihylhexyl) phthalate to duckweeds

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.

Occurrence of microcystins in water,sediment,and aquatic animals in Dau Tieng Reservoir,Vietnam

This study investigates the variations of microcystins(MCs)in water,cyanobacterial blooms,sediment,and aquatic organisms collected from the Dau Tieng Reservoir(DTR).Vietnam.Highperformance liquid chromatography(HPLC)was employed to measure MC concentrations in various target samples.Results indicate that Microcystis spp.dominates as the primary MC producer in the DTR.The average concentrations of analyzed MCs in surface water ranged from 1.10 to 5.54μg/L,temporally and spatially.In sediment,average concentrations varied from 0.15 to 1.13μg/g wet weight(WW)temporally and from 0.41 to 0.72μg/g WW spatially.MCs were detected in different organs of fish species(Oreochromis sp.and Labiobarbus sp.)and in the entire soft tissues of bivalve(Corbicula sp.)and gastropod(Assiminea sp.).The highest observed MC concentration in July was 0.83±0.22μg/g WW in the intestines of fish Oreochromis sp.The presence of MCs in grass shrimp Palaemonetes sp.was observed solely in June,reaching a concentration of 0.28±0.19μg/g WW.This is the first report of MC accumulation in the grass shrimp Palaemonetes sp.during field collection.For the bivalve Corbicula sp.,the presence of analyzed MCs was consistent throughout the study period,except for March and September,with the highest concentrations in July at 0.77±0.1μg/g WW.Pearson correlation analysis revealed significant positive correlations between MCs in water and sediment with MC concentrations in aquatic animals,indicating the potential transfer of MCs across different trophic levels.The estimated daily intake values for analyzed MCs indicate that fish collected from the DTR are considered safe for consumption,as long as only the edible organs,such as the muscle,are consumed.However,bivalves or gastropods collected from the DTR are not safe for human consumption.This study underscored the importance of monitoring MC accumulation in aquatic animals used as food to mitigate adverse effects on human health.

Eco-toxicity and health risk assessment of polycyclic aromatic hydrocarbons in surface sediments of Burullus Lake in Egypt

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.

Toxic response of aquatic organisms to guide application of artemisinin sustained-release granule algaecide

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.

Quantitative Correlation of the Acute Toxicity of Phenylthio-carboxylates with Their Structural and Thermodynamic Parameters by DFT Calculation

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.

AquaticTox:A Web-Based Tool for Aquatic Toxicity Evaluation Based on Ensemble Learning to Facilitate the Screening of Green Chemicals

The widespread use of chemical products inevitably brings many side effects as environmental pollutants.Toxicological assessment of compounds to aquatic life plays an important role in protecting the environment from their hazards.However,in vivo animal testing approaches for aquatic toxicity evaluation are timeconsuming,expensive,and ethically limited,especially when there are a great number of compounds.In silico modeling methods can effectively improve the toxicity evaluation efficiency and save costs.Here,we present a web-based server,AquaticTox,which incorporates a series of ensemble models to predict acute toxicity of organic compounds in aquatic organisms,covering Oncorhynchus mykiss,Pimephales promelas,Daphnia magna,Pseudokirchneriella subcapitata,and Tetrahymena pyriformis.The predictive models are built through ensemble learning algorithms based on six base learners.These ensemble models outperform all corresponding single models,achieving area under the curve(AUC)scores of 0.75−0.92.Compared to the best single models,the average precisions of the ensemble models have been increased by 12−22%.Additionally,a self-built knowledge base of the structure-aquatic toxic mode of action(MOA)relationship was integrated into AquaticTox for toxicity mechanism analysis.Hopefully,the user-friendly tool(https://chemyang.ccnu.edu.cn/ccb/server/AquaticTox);could facilitate the identification of aquatic toxic chemicals and the design of green molecules.

Structural Characterization and Aquatic Toxicity Prediction of Esters

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.

Next generation per-and poly-fluoroalkyl substances:Status and trends,aquatic toxicity,and risk assessment

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.

Using theoretical solvatochromic parameters in prediction of acute toxicity of substituted aromatic compounds to aquatic organisms

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

Prediction of metal toxicity in aquatic organisms

Metal pollution has been a major environmental problem in China with the increasing industrialization.The prediction of metal toxicity is extremely challenging due to the complex metal handling and sequestration strategies of different aquatic organisms.In this review,the recent progress made in this area is discussed.In particular,the subcellular partitioning model which has gained recognition in recent years is highlighted.The subcellular partitioning model appears to be dependable for predicting the toxicity in unicellular phytoplankton.It is important to understand the differential ways that metals bind to different subcellular pools and their ecotoxicological significance in aquatic organisms under different exposure regimes.It is also critical to appreciate that every metal is unique to each aquatic species.Despite the huge progress made over the past 30 years,much remains to be done to fully understand metal toxicity in aquatic organisms.

磺胺类药物水环境行为及水生生物毒性研究进展

磺胺类药物(SAs)在水环境中普遍存在,大部分SAs以母体分子或代谢产物形式排放到环境中,地表水、地下水、海水甚至饮用水中都能检测到低浓度的SAs。因SAs排放量大、环境假性持久性强等特点,其对水生态环境和人类健康构成潜在风险。针对SAs在水环境中的归趋问题,总结了SAs在水环境中吸附、迁移、转化、降解、生物富集等典型行为规律,进一步分析SAs对水生植物、水生动物及水生微生物产生的毒性效应。结果表明:SAs在水环境中行为的研究多集中在环境介质表面的吸附特性与规律,而对SAs依赖水动力条件的迁移转化和生物富集规律研究较少;SAs在环境介质表面的吸附主要以阳离子交换和分子结合的形式发生,吸附质表面的电荷密度是决定吸附量的重要因素;SAs在水环境中广泛存在,虽然浓度水平较低,但对水生生物造成的负面影响会产生潜在的生态风险,主要表现为干预水生植物的生长发育过程,造成水生动物的特征性畸形,干扰水中微生物的群落结构与功能,最终会对整个水环境及其循环造成宏观的影响。未来应加强SAs在水环境中衰减过程的浓度和贡献率研究以及对水生生物毒性标准化测试,以期深入研究SAs生态毒理学、解决SAs污染问题。

淮河流域土霉素水质基准及生态风险评估

土霉素是最常见的四环素类药物之一,在畜牧业中应用广泛。规模化养殖企业废水达标排放,抗生素浓度不是必测指标,可能危害地表水生态系统。目前我国抗生素水质标准制定存在缺失,淮河流域土霉素标准限值、土霉素浓度、生态风险评估相关研究少,尚未以保护该流域水生生物为目标开展水质基准相关研究。本研究采用物种敏感度分布法,基于大型溞、鲤鱼、普通水螅等6门9科11种急性毒性数据,推导出土霉素淡水生物短期水质基准为92.52μg/L,基于模糊网纹溞、臂尾轮虫、大型溞、四尾栅藻、普通水螅等6门10科10种慢性毒性数据,推导出土霉素淡水生物长期水质基准为75.85μg/L,建议土霉素长期水质基准75.85μg/L作为淮河流域土霉素标准值。生态风险评估结果显示淮河流域层面土霉素不对河流生物完整性构成威胁,但畜牧业发达地区水环境土霉素均值显著偏高,需加大对养殖企业排口附近水域或河流枯水季等稀释比较小季节土霉素的检测与控制,减少对水生生物完整性冲击。

砷在水生生物中的生物累积、转化及在其他生物体内的代谢毒理学研究进展

砷作为全球水生生态系统的重要污染物,普遍存在于淡水和海洋环境中,具有一定的生物累积性与生物毒性.水生生物作为生态系统的重要组成部分,砷在全球生物化学循环的过程中通过迁移、累积、转化、富集在水生生物体内,产生毒性作用,而砷对水生生物的毒性与其在水生生物中的赋存形态有关.目前关于砷在水生生物中的生物累积、生物转化及其代谢毒理的基础科学研究受到国内外研究者的广泛关注,而少有对该领域内的研究进展、研究热点、趋势方向的系统整合,本文针对这一领域文献进行梳理,系统阐述了砷在水生生物中的生物累积和生物转化情况;概述了砷在水生生物、小鼠/大鼠、人体、微生物等生物中的毒性作用及代谢机制;并提出了未来有关砷研究可关注的重点及方向.本文可为进一步阐明砷在水生生物中的生物累积转化规律及砷的代谢毒性作用,为研究者进一步深入探索该领域内科学问题提供参考资料,同时对水产品安全、环境生态、医学等相关领域的研究具有一定的借鉴意义.

化学农药对稻渔综合种养中非靶标生物毒性影响研究进展

稻渔综合种养是一种将水稻与水产养殖动物协调共作的复合型生态农业模式,化学农药广泛用于水稻病虫害防治,其对稻田环境以及稻田综合种养田中水生生物/水禽的毒性影响逐渐受到广泛关注.介绍了常见稻渔综合种养模式中常用化学农药对非靶标生物的毒性的影响研究进展.

Hypoxic and temporal variation in the endocrine disrupting toxicity of perfluorobutanesulfonate in marine medaka(Oryzias melastigma)

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.

全氟/多氟烷基化合物淡水生物水质基准研究现状与展望

全氟/多氟烷基化合物(PFASs)是指一个或多个碳链上的氢原子被氟原子部分或完全取代的一类化合物。已有大量研究表明PFASs在水环境中污染严重,并会对水生生物造成发育毒性、神经毒性、生殖毒性、内分泌干扰效应等危害。目前美国、澳大利亚、加拿大、欧盟等国家或地区针对全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)两种传统的PFASs已经发布了淡水生物水质基准,为深入了解PFASs淡水生物水质基准的研究现状以及在基准制定过程中面临的挑战,本研究系统总结了各国家或地区PFOA和PFOS的淡水生物水质基准阈值,对比分析了不同国家或地区在物种选择、数据来源、基准推导方法等方面的差异。结果表明,各国家或地区水质基准阈值存在较大差异,在2~6个数量级之间,究其原因主要是:①不同国家或地区选择的受试物种差异较大,涵盖的分类群不同。②PFASs毒性效应繁多、实验设计缺乏统一标准,导致不同研究结果之间存在较大差异,且各国家或地区对是否采用某一实验毒性数据的标准不同。③使用急慢性比率外推得到的慢性毒性数据具有较高的不确定性。④各国家或地区推导PFASs水质基准的方法不同。研究显示,目前PFASs淡水生物水质基准仍然面临管控物质单一、基础毒性数据不足、生物累积性影响不明、混合效应影响不明、基准推导方法不确定等挑战。为了更好地保护水生态系统,需要通过多学科交叉合作、全球数据共享、毒性预测等方法深入了解PFASs的环境行为、毒性效应、生物累积特征等,以支撑更多PFASs水质基准的科学制定。

稀土元素在水环境中的生物有效性和毒性研究进展

稀土元素(rare earth elements,REEs)已广泛应用于高科技和清洁生产等领域,并可能通过生产和使用等环节进入水生生态系统。水环境中的REEs可以是自由离子态,或与配体形成络合物,也可以作为胶体留在水相中。REEs可以被水生生物吸收,或吸附在其表面,并通过食物链进行传递,对水生生物或人体造成潜在风险。本文概述了国内外部分水环境中REEs的环境浓度、赋存形态和分布,及其影响因素,总结了目前水环境中REEs在不同营养水平的生物累积和食物链传递规律,阐述了REEs在分子、细胞、器官和个体水平下所产生的毒性和致毒机理,及影响其毒性的生物和非生物因素,并对今后REEs的生物有效性和毒性研究进行展望。

水生生物毒性测试用于沉积物评价的研究进展

针对沉积物污染问题的研究目前已建立了不同的评价方法与体系,目前常用的结合生物毒性测试的有效应导向分析(EDA)、沉积物毒性鉴别评价(TIE)、证据权重法(WOE)、物种敏感性分布法(SSD)和沉积物质量基准(SQG)等,这些方法在河流、湖泊等水体沉积物中污染物毒性效应表征及沉积物质量评价方面有重要应用.本文指出水生生物毒性测试应用的重要性,根据不同学者的研究内容归纳了水生生物毒性测试的方法学,对沉积物进行水生生物毒性测试的基质处理包括直接采用污染沉积物、洁净沉积物加标以及人工配置沉积物,受试生物主要包括浮游植物、浮游动物、底栖动物和鱼类,毒性试验终点包括急性毒性终点和慢性毒性终点;最后指出水生生物测试存在的问题,并对沉积物质量评价未来发展方向进行展望,以期为我国沉积物生物毒性测试标准方法的建立提供参考.

微塑料和抗生素对水生生物联合毒性效应研究进展

微塑料作为一种新型污染物已引起全球性的环境问题,由于粒径小、分布广、疏水性强、难降解等特性,受到越来越多研究人员的关注。水环境中微塑料与其他污染物往往会发生相互作用,产生更严重的环境效应,对水生生物造成不同程度的危害,还会严重威胁人类健康。本文综述了水环境中微塑料与抗生素的来源、污染现状,阐述了微塑料和抗生素的相互作用,重点讨论了微塑料和抗生素对水生生物(动物、植物和微生物)的联合毒性效应,并对未来微塑料与抗生素复合污染方面的研究进行了展望。为进一步研究复合污染对水生生物的生态毒性效应和水体复合污染的环境治理提供参考,同时为水体中复合污染的风险评估提供重要理论依据。

水环境优控污染物筛选研究进展

随着社会经济的快速发展,大量污染物排放到水环境中,使得水环境污染和治理问题备受关注.明确水环境优控污染物是科学有序开展水污染治理的前提.本文综述了水环境优控污染物筛选的原则和常用技术方法,并分析了不同方法的优缺点.通过比较不同水环境体系优控污染物的筛选结果,发现不同系统的优控污染物名单具有较大差异,因此应根据各地不同的污染特征,制定因地制宜的优控污染物名单.此外,在传统污染物筛选工作的基础上,未来应加强对新污染物的监测和评估,及时更新优控污染物名单,为水环境的保护和治理提供更全面的决策依据.