Urban wastewater contains various pollutants, with heavy metals being common, posing risks to the environment and public health, especially when used for irrigation in agricultural systems. This study aimed to assess ...Urban wastewater contains various pollutants, with heavy metals being common, posing risks to the environment and public health, especially when used for irrigation in agricultural systems. This study aimed to assess the total and bioavailable content of Pb and Cr in agricultural soil irrigated with wastewater and their accumulation in alfalfa crops. Five alfalfa sites were sampled, and ten surface soil samples were collected from the top 30 cm of each plot. Plant samples were also collected at each sampling point. A composite sample of irrigation water from the main channels was also collected and prepared. The concentration of heavy metals was determined using atomic absorption spectrophotometry. The results revealed concentrations of Pb and Cr (VI) in the irrigation water above the maximum permissible limits according to environmental regulations. The soil had high organic matter content, neutral pH, elevated electrical conductivity (EC), and Pb and Cr contents of up to 103 and 89 mg/kg, respectively. In alfalfa tissues, Pb and Cr concentrations were recorded at 26 mg/kg and 4.6 mg/kg, respectively (Cr (VI), with lower concentrations observed in the roots. Cr (VI) was higher at all sites, with ranges from 2.25 to 43.56, while lead (Pb) had an AR ranging from 0.64 to 27.04. The Pb presented a mean of 1.45 of the Bioaccumulation factor values, which can be considered a metal-accumulating plant.展开更多
Intensive use of sulfamethazine(SM_2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on ...Intensive use of sulfamethazine(SM_2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on the bioaccumulation and biodegradation of SM_2 in Chlorella pyrenoidosa. The microalgae were treated with 2, 4, and 8 mg L^(-1) of sulfamethazine for 13 days, respectively, showing that the inhibition effects of sulfamethazine on the growth of Chlorella pyrenoidosa increased progressively as the concentrations of sulfamethazine increasing from 2 to 8 mg L^(-1). The peak concentrations of sulfamethazine accumulated in C. pyrenoidosa were 0.225, 0.325, and 0.596 ng per mg FW on day 13 for three treatment groups, respectively, showing a great ability to deplete sulfamethazine from the culture media. On day 13, the percentages of biotic degradation were 48.45%, 60.21% and 69.93%, respectively. The EC_(50) of 10.05 mg L^(-1) was derived which showed no significant risk for C. pyrenoidosa with a calculated risk quotient < 1. The activities of superoxide dismutase and catalase increased progressively in response to sulfamethazine and showed a positive correlation to the treatment concentrations. The highest superoxide dismutase activity was achieved at the concentration of 8 mg L^(-1) after 2 d of exposure, which was 1.89 folds higher than that of the control. The activity of catalase has a similar pattern to that of superoxide dismutase with the maximum activity achieved at day 2, which was 3.11 folds higher compared to that of the control. In contrast to superoxide dismutase and catalase, the maximum glutathione S-transferase activity was observed at day 6, showing 2.2 folds higher than that of the control.展开更多
Bioaccumulation of heavy metals in tea marketed in Nigeria was investigated. Four major and most consumed brand of tea were selected for the present study. Both aqueous and dry methods were used. Total contents of met...Bioaccumulation of heavy metals in tea marketed in Nigeria was investigated. Four major and most consumed brand of tea were selected for the present study. Both aqueous and dry methods were used. Total contents of metal were determined by digesting 1g of each brand using a mixture (3:1) concentrated nitric acid (NNO3) and hypochlorous acid (HCLO4). The second method involved hot water extract of tea samples. After boiling and filtration, the residue was evaporated to near dryness and digested with concentrated HNO3 and HCLO4 as described above. Results indicate that Zn, Cd, Cu, and Pb were present in lowest concentrations in ascending order for which there were two significant differences between the four sources of samples. The general characteristics of heavy metal concentrations in aqueous extract showed high level of Fe and Mg in a descending order. Going by the correlation study of our result indicates that there is no significant relationship between the two elements of Fe and Mg, though, the numerical values of the two elements varied widely among the samples. These differences may have major impact on human health. However, the beneficial effects of tea are in a fairly narrow concentration range between the essential and the toxic level. In conclusion, the variations in heavy metals content of tea brands may be due to geographical, seasonal changes and the chemical characteristics of the growing regions.展开更多
The studies on bioaccumulation and distribution of the plant growth regulator multi - effect triazole( MET) in the fish (Carassias auratus) and Daphnia (D. magna) showed that the bioaccumulation factor(BCF) was in pos...The studies on bioaccumulation and distribution of the plant growth regulator multi - effect triazole( MET) in the fish (Carassias auratus) and Daphnia (D. magna) showed that the bioaccumulation factor(BCF) was in positive correlation to the lipid content展开更多
This study was aim to determined the levels of some heavy metals in the gills, liver, stomach, kidney, bones and flesh of four fish species (Tilapia zilli, Clarias anguillaris, Synodentis budgetti and Oreochronmis nil...This study was aim to determined the levels of some heavy metals in the gills, liver, stomach, kidney, bones and flesh of four fish species (Tilapia zilli, Clarias anguillaris, Synodentis budgetti and Oreochronmis niloticus) collected at River Benue in Vinikilang, Adamawa State, Nigeria for analysis of Cu, Zn, Co, Mn, Fe, Cr, Cd, Ni and Pb. These metals were chosen because at higher concentrations there might be toxic to the fish and by extension humans that depends on such fish as food. The concentrations of the metals were carried out using Flame Atomic Absorption Spectrophotometer (AAS, Unicam 969). Large differences in trace metal concentrations were observed between different tissues within each fish. The highest concentration of Fe (12.65 μg/g) was recorded in gill of Synodentis budgetti, while the lowest value of 0.68 μg/g was recorded in the flesh of Oreochronmis niloticus. The liver of Synodentis budgetti accumulates significant higher levels of Mn and Cd than other species;Fe and Zn was highest in the stomach of Tilapia zilli, while Clarias angullaris shows more of Cr, Pb, Cd and Co. The stomach of Synodentis budgetti accumulate significant higher levels of Fe than other species;Zn was highest in the stomach of Tilapia zilli, while Clarias angullaris shows more of Mn, Cr, Cu, Cd and Pb. Similarly, the bone of Synodentis budgettiaccumulates significant higher levels of Mn and Cd than other species;Zn and Fe were highest in the bone of Tilapia zilli, while Clarias angullaris shows more of Cr, Pb, Ni, and Co. The highest levels of Fe (12.65 μg/g) observed in this study was recorded in the gill of Synodentis budgetti and it was below the high residue concentrations of Fe (34 - 107 ppm) in fish samples. Based on the above results, it can therefore be concluded that metals bioaccumulation in the entire fish species study did not exceeds the permissible limits set for heavy metals by FAO, FEPA and WHO.展开更多
The prevailing hypothesis, which states that the uptake of HOCs by phytoplankton is controlled by the compound’s lipophilicity (Kow) was tested. The approach taken was to determine the factors that controlled the upt...The prevailing hypothesis, which states that the uptake of HOCs by phytoplankton is controlled by the compound’s lipophilicity (Kow) was tested. The approach taken was to determine the factors that controlled the uptake of PCBs by phytoplankton under controlled laboratory conditions, and to develop a model that would describe bioaccumulation of PCBs in phytoplankton.The results demonstrate a relationship of BAF to Kow and to phytoplankton surface properties, as well as the data presented here, support the hypothesis that the mechanism of HOC uptake is a rapid surface sorption followed by a slower transfer into lipids in the cell matrix. The work on the kinetics of uptake indicates that equilibrium is reached slowly and that the rate of uptake is of similar magnitude as phytoplankton growth under normal field conditions.Thus a critical factor that controls the bioaccumulation of HOCs reach equilibrium in phytoplankton itself.展开更多
Objective:To investigate the level of heavy metals(Cu,Zn,Fe Mn Ni,Pb and Cd) in muscles,gills and liver tissue of Croaker fish from oil spilled rivers of Bonny and Finima,Niger Delta region,Nigeria.Methods:Twenty four...Objective:To investigate the level of heavy metals(Cu,Zn,Fe Mn Ni,Pb and Cd) in muscles,gills and liver tissue of Croaker fish from oil spilled rivers of Bonny and Finima,Niger Delta region,Nigeria.Methods:Twenty four Croacker fishes(Genyonemus lineatus) weighing between 250 and 260 g and 24–26 cm length were collected from each sampling sites(Bonny and finima rivers).The frozen fishes were thawed and dried at 105C until they reach a constant weight.The dried samples were homogenized and digested with 10 ml tri-acid mixture(HNO3:HCl O4:H2SO4),and then the digested samples were diluted to 100 ml with deionized water.Heavy metals(Cu,Ni,Zn,Pb,Mn,Iron Fe,and Cd) concentrations were determined by atomic absorption spectrophotometer.Results:Our results revealed that concentrations and distribution patterns of all heavy metals studied varied significantly(P < 0.05) amongst the fish tissues analyzed and sampling sites.Moreover,liver tissue of fish caught from Finima creek accumulated the highest concentrations of Cu(52.64 ± 3.01 mg/g dry wt),Zn(166.50 ± 6.45 mg/g dry wt)and Fe(801.50 ± 14.15 mg/g dry wt) in comparison to the liver of fish caught from Bonny river in which the levels of Cu,Zn and Fe were(45.00 ± 2.79),(49.90 ± 2.91) and(216 ± 6.11 mg/g dry wt),respectively.In addition,Mn,Ni,Pb and Cd exhibited their highest concentrations in gills from both locations.As expected,muscle tissue contained the least concentrations of all metals investigated from both sampling sites.Furthermore,all the metals investigated exhibited highest concentration in fish collected from Finima creek.These abnormal high level heavy metals accumulation observed in this location could be linked to the frequent crude oil spills as well as industrial activity around the area which might get discharged into Finima creek.In general,the mean concentrations of some toxic heavy metals investigated exceed the recommended maximum permissible limits set by the Joint FAO/WHO committee.However,some metals are within the acceptable limits.Conclusions:In conclusion,our data showed the abnormal higher concentration of these metals and this might be toxic to the fish and other aquatic organisms directly or by extension to humans that frequently consumed such contaminated fishes.展开更多
Etrazine is one of the most widely used herbicides in China and the world.Acute and chronic toxicity tests were carried out to assess the possible toxicity effect of atrazine on crucian carp(Carassius auratus).Results...Etrazine is one of the most widely used herbicides in China and the world.Acute and chronic toxicity tests were carried out to assess the possible toxicity effect of atrazine on crucian carp(Carassius auratus).Results showed that 96 h LC50 of atrazine to Carassius auratus was 105.94 mg L-1.The enzyme activities of superoxide dismutase(SOD),catalase(CAT) and glutathione-S-transferases(GST) in kidney of Carassius auratus were all influenced by atraizine,and CAT was more sensitive to atrazine compared with SOD and GST.Atrazine residues in kidney of Carassius auratus reached the stable state at day 19,and the bioaccumulation factors(BAF) of atrazine in kidney of Carassius auratus treated with 1.0 mg L-1 and 10.0 mg L-1 atrazine were 8.3 and 4.4,respectively.The research demonstrated that atrazine could cause oxidative stress to fish kidney,but atrazine was not easy to accumulate in Carassius auratus kidney,and the antioxidant enzymes could be used as biomarker to the early detection of pollution.展开更多
Concentration of Cadmium, Copper, Lead, Zinc and Mercury were determined in the muscles, gills and liver of ten fish species (Epinephelus areolatus, Epinephelus radiates, Anthias squamipinnis, Plectorhinchus chaetodon...Concentration of Cadmium, Copper, Lead, Zinc and Mercury were determined in the muscles, gills and liver of ten fish species (Epinephelus areolatus, Epinephelus radiates, Anthias squamipinnis, Plectorhinchus chaetodonoides, Snubnose emperor, Dicentrarchus labrax, Acanthopagrus bifasciatus, lutjanus kasmira, lutjanus ehrenbergii and Acanthurus gahhm) as well as three specimens of crustaceans (Metapenaeus dalli, Panulirus penicillatus and Portunus petagicus) and two Specimens of squids (Parateuthis tunicate and Chtenopteryx sicula) collected from Jeddah coastal water during 2014. The obtained results declared that, the average concentrations of heavy metals were as follows: Cd (0.098, 0.20, 0.106), Cu (0.358, 0.327, 1.536), Pb (0.3, 0.257, 0.196), Zn (3.00, 7.390, 4.999) μg/g wet weight in the muscle, gills and liver, respectively. While, the concentration of Hg was invariably undetectable in all samples of different organs of the collected fish species. The average concentration of Cd, Cu, Pb, Zn and Hg in the soft part of the investigated crustaceans (Metapenaeus dalli, Panulirus penicillatus and Portunus petagicus) and squids (Parateuthis tunicate and Chtenopteryx sicula) were relatively higher compared with the muscle tissues in the examined fish species. The results of bioconcentration factor (BCFs) indicated that among examined metals Zn was the most readily absorbed by fish and the highest BAFs for examined fish species were determined in gill of Snubnose emperor.展开更多
The use of biomarkers has become an important tool for modern environmental assessment as they can help to predict pollutants involved in the monitoring program. Here I present data on bioaccumulation, biochemical and...The use of biomarkers has become an important tool for modern environmental assessment as they can help to predict pollutants involved in the monitoring program. Here I present data on bioaccumulation, biochemical and tissues biomarkers in Nile tilapia as early warning indicators of river Nile pollution. Nile tilapia sampled from downstream sites accumulated higher levels of all the detected heavy metals than those collected from upstream sites. Heavy metal residues in the tissues of Nile tilapia exhibited different patterns of accumulation and distribution among the selected tissues. Remarkable alterations in the activities of glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) in the tissues of Nile tilapia were detected. These alterations were followed, in the present study, by the occurrence of histological lesions in liver and gill tissues of fish collected from the same sites. Alterations in bioaccumulation patterns, in enzyme activities and in histology go in parallel with the elevation in the levels of water chemical parameters detected in the downstream sites as a result of pollution stress in these areas. These results provide evidence that bioaccumulation, biochemical and tissues biomarkers can be sensitive indicators of exposure to mixed pollutants in surface waters.展开更多
Several mechanisms are developed by the microorganisms to tolerate few high concentrations of heavy metals. One of these mechanisms dependent upon anabolic and catabolic energy of microorganisms is the bioaccumulation...Several mechanisms are developed by the microorganisms to tolerate few high concentrations of heavy metals. One of these mechanisms dependent upon anabolic and catabolic energy of microorganisms is the bioaccumulation of heavy metals. In present work, approximately four varieties of bacteria have been isolated from the ash dyke sample of four thermal power plants of Chhattisgarh, i.e., Bharat Aluminium Company (BALCO), Chhattisgarh State Electricity Board (CSEB), Korba, Thermal Power Cooperation (NTPC), Bilaspur and KSK Akaltara, Chattisgarh. Out of one hundred fifty isolates, three were capable to grow in varying concentration of heavy metals. The strains were tested for their tolerance against six different types of heavy metals dominant in the ash samples viz. Pb, Hg, Ni, Co, Cu, Mn. Their maximum resistance existed up to 0.6mM/ml of the above mentioned different metals under lab standard conditions. Three isolates are found suitable for the multiple metal resistance ability viz SM2, SM3, and SM12. These are categorized as Bacillus cereus (SM2, SM3), and Bacillus subtilis (SM12) after performing 16S rDNA sequencing.展开更多
In the present study, the two lakes, Vengaiah lake (Lake A-Sewage polluted receiving discharge from storm water drain) and Yellamallappa Chetty lake (Lake B-Industrially polluted) situated near Krishnarajpuram-Hoskote...In the present study, the two lakes, Vengaiah lake (Lake A-Sewage polluted receiving discharge from storm water drain) and Yellamallappa Chetty lake (Lake B-Industrially polluted) situated near Krishnarajpuram-Hoskote taluk, Bangalore, Karnataka were selected for analysis of trace metals viz., arsenic, aluminium, cadmium, lead, mercury, iron, copper and zinc in water samples. Muscle and gill tissues of freshwater fish Labeo rohita reared in these water bodies were analysed for bioaccumulation of trace metals. Hebbal fish farm was considered as a reference site (Control site) for water and fish samples. Trace metals were analysed by atomic absorption spectroscopy and values were compared with those recommended by FAO/WHO in water and fish samples. Trace metals such as Al, As and Hg were detected in the water sampled from lake B which is attributed to the differences in the sources of pollutants. Fish tissues viz., muscle and gills sampled from Lake B exhibited high concentration of Al, Pb and Cd content showing a positive correlation with their concentration in water samples. The remaining metals as Cu, Zn and Fe were detected in water sampled from all water bodies and also in the fish tissues. Gills exhibited higher concentration of metals in fish from lake B. Bioaccumulation of these trace metals in fish tissues may cause potential danger to human health when consumed on regular basis. Thus necessary remedial measures are required to combat water contamination and its management keeping in view the aquatic ecosystem and public health. Values were statistically significant at P < 0.0001.展开更多
The roads in correlation with the traffic linked to their existences are at the origin of the emission of numerous polluting substances likely to induce disturbances of the growth and the behavioral changes in the org...The roads in correlation with the traffic linked to their existences are at the origin of the emission of numerous polluting substances likely to induce disturbances of the growth and the behavioral changes in the organisms living in their vicinities. The purpose of this study is to analyze the growth and capacity accumulation of a common earthworm species (Millsonia omodeoi) in Cu, Cr, Ni, Pb and Zn in soils along a main road called “Autoroute du Nord” in C?te d’Ivoire. Thus, the earthworms were harvested in soils from a distance of 0 m (just after the sidewalk) to a distance of 200 m from the toll highway and in a control soil sampled in Lamto reserve (C?te d’Ivoire). The study was carried out in the soil laboratory at the ecological station of Lamto reserve. The Ford-Walford technique was used to determine the model and parameters most appropriated for describing the growth of earthworms. A pairwise comparison of the growth parameters was carried out using the Kruskal-Wallis test with the STATISTICA 7.1 software. The heavy metals contained in the cultivated soils and earthworms were detected and quantified using a Scanning Electron Micro-scope (MEB FEG Supra 40 VP Zeiss) and an Atomic Absorption Spectrometer SPECTRA 110 (VARIAN). The capacity accumulation of heavy metals in earthworm was determined by the bioaccumulation factor (BAF) calculation. The results of this study showed that Gompertz is the most appropriated model to describe the growth of M. omodeoi. The life cycle of M. omodeoi shows that this earthworm adopts a K type demographic strategy. Cu is the most accumulated heavy metals in M. omodeoi, when Cr is the least accumulated. Concerning heavy metal content in the earthworms, it decreases while moving away from the pavement. These results highlight a possibility of choice of M. omodeoi as 1) indicators of heavy metals pollution and 2) target of biological organisms for environmental impact studies.展开更多
Dietary uptake is the major way that inorganic arsenic(iAs)enters into benthic fish;however,the metabolic process of dietborne i As in fish muscle following chronic exposure remains unclear.This was a 40-day study on ...Dietary uptake is the major way that inorganic arsenic(iAs)enters into benthic fish;however,the metabolic process of dietborne i As in fish muscle following chronic exposure remains unclear.This was a 40-day study on chronic dietborne i As[arsenite(AsⅢ)and arsenate(AsⅤ)]exposure in the benthic freshwater food fish,the crucian carp(Carassius auratus),which determined the temporal profiles of iAs metabolism and toxicokinetics during exposure.We found that an adaptive response occurred in the fish body after iAs dietary exposure,which was associated with decreased As accumulation and increased As transformation into a non-toxic As form(arsenobetaine).The bioavailability of dietary AsⅢwas lower than that of AsⅤ,probably because AsⅢhas a lower ability to pass through fish tissues.Dietary AsⅤexhibited a high potential for transformation into AsⅢspecies,which then accumulated in fish muscle.The largely produced AsⅢconsidered more toxic at the earlier stage of AsⅤexposure should attract sufficient attention to human exposure assessment.Therefore,the pristine As species and exposure duration had significant effects on As bioaccumulation and biotransformation in fish.The behavior determined for dietborne arsenic in food fish is crucial for not only arsenic ecotoxicology but also food safety.展开更多
In this paper,we report the bioaccumulation and transformation of cadmium (Cd) by Phaeodactylum tricornutum in the presence of ethylenediamine tetra acetic acid (EDTA) and cysteine (Cys). Both EDTA and Cys can allevia...In this paper,we report the bioaccumulation and transformation of cadmium (Cd) by Phaeodactylum tricornutum in the presence of ethylenediamine tetra acetic acid (EDTA) and cysteine (Cys). Both EDTA and Cys can alleviate the toxicity of Cd to P. tricornutum. Short term intracellular uptake and extracellular adsorption experiments using ICP-MS indicated that the amounts of Cd accumulated on the cell surface of P. tricornutum and inside the cell decreased along with the increase of EDTA concentration,which conformed to the prediction of the Free Ion Activity Model (FIAM). However,extracellular adsorption of Cd increased at first and then decreased along with the increase in the concentration of Cys,while intracellular uptake increased under Cys concentrations from the blank value to 4.45 μmol/L,and then tended to remain at the same level when the Cys concentration was greater than 4.45 μmol/L,and this deviated remarkably from the FIAM. The interactions of Cd with _Si_OH,_C_OH and NH2(CO) _OH on the cell wall were confirmed using FT-IR and XPS studies. The results obtained using HPLC of the phytochelatins (PCs) produced by P. tricornutum under CdCl2,Cd_EDTA and Cd_Cys stress suggested that the main reason for the different effects of EDTA and Cys on the bioaccumulation and transformation of Cd by P. tricornutum was that Cys is not only a complexing ligand to Cd,as is EDTA,but also it is a precursor of the intracellular synthesizing PCs participating in the cellular defense mechanism against Cd. Furthermore,the discovery of in vivo PCs and oxidized_PCs as well as Cd-PC2 in P. tricornutum using ESI-IT-MS provided the evidence for deactivation of Cd by the PCs,reducing Cd-toxicity to P. tricornutum.展开更多
Trace metal contamination in water and bioaccumulation in aquatic organisms are human health risks of increasing concern. However, the bioaccumulation of trace metals in the organs of the mussel Cristaria plicata in D...Trace metal contamination in water and bioaccumulation in aquatic organisms are human health risks of increasing concern. However, the bioaccumulation of trace metals in the organs of the mussel Cristaria plicata in Dongting Lake, China and the human health risks of mussel consumption are largely unknown. We investigated the concentrations of 15 trace metals and metalloids in surface water, sediments, and C. plicata organs(foot, gill, mantle, and visceral mass) and quantified the bioaccumulation and human health risk of these trace metals in specimens collected from Dongting Lake. The concentrations of most metals in surface water exceeded previously published background values. In contrast, the concentrations of most metals in sediments showed a decreasing trend. Overall, the metal concentrations in the gill and visceral masses of C. plicata were higher than those in the foot and mantle, and higher bioaccumulation capacities were observed for essential metals than for nonessential metals. The mean concentrations of the trace elements Zn, Pb, Cd, As, Cu, and Cr in C. plicata foot samples were lower than the threshold values established by international and Chinese organizations. The estimated daily intake(EDI) values of the essential metal Mn in C. plicata foot was higher than the recommended tolerable daily intake(TDI) values for juveniles. Only Mn for juveniles and As for both juveniles and adults may pose noncarcinogenic health risks through foot consumption. The hazard index(HI) values for adults and juveniles were higher than 1, suggesting significant risks of noncarcinogenic effects to humans by exposure to multiple metals.展开更多
As a global toxic pollutant,mercury(Hg)bioaccumulation within food chain could be influenced by human disturbance.Ten typical fish species were collected from Changshou Lake,an artificial lake used to carry out cage f...As a global toxic pollutant,mercury(Hg)bioaccumulation within food chain could be influenced by human disturbance.Ten typical fish species were collected from Changshou Lake,an artificial lake used to carry out cage fish culture,to investigate the C/N isotopic compositions and Hg bioaccumulation in fish.The results showed that the total Hg(THg)and methylmercury(MeHg)levels in fish muscles((56.03±43.96)and(32.35±29.57)ng/g,wet weight),comparable with those in most studies in China,were significantly lower than the international marketing limit(0.5 mg/kg).Past human input for cage culture in this lake led to abnormal^(15)N enrichment in food chain,as the quantitative trophic levels based onδ^(15)N were different with that classified by feeding behaviors.This phenomenon subsequently demonstrated that it should be considered thoughtfully with respect to the application of the traditional method for understanding Hg bioaccumulation power by the slope of log_(10)[Hg]withδ^(15)N regression in specific water body(i.e.,Changshou Lake).In addition,no significant linear correlation between Hg and body weight or length of some fish species was observed,suggesting that the fish growth in the eutrophic environment was disproportionate with Hg bioaccumulation,and fish length or weight was not the main factor affecting Hg transfer with food web.The occurrence of human disturbance in aquatic system presents a challenge to a better understanding of the Hg bioaccumulation and biomagnification within the food chain.展开更多
Trace metal(Cr, Ni, Cu, Zn, Cd and Pb) exposures, distribution and bioaccumulation were investigated in marine organisms from Guangdong coastal regions, South China. The results showed that all of the selected metals ...Trace metal(Cr, Ni, Cu, Zn, Cd and Pb) exposures, distribution and bioaccumulation were investigated in marine organisms from Guangdong coastal regions, South China. The results showed that all of the selected metals were observed in marine organisms with a predomination of Cu and Zn. The metal exposure levels exhibited obvious variations between species with the decreasing order of crab > shellfish > shrimp > fish. The higher metals enrichment seen in shellfish and crab species primarily attributed to their living habits and the higher sediment background values of trace metals. Endpoint bioaccumulation factor(BAFfd) was used to characterize the bioaccumulation potentials of marine organisms to trace metals, of which Cu and Zn were the most accumulated elements. The exposure of trace metals in the cultured organisms was far lower than those in wild marine organisms, which is probably due to the effect of growth dilution. Comparisons with previous studies demonstrated that the concentration profiles of most trace metals declined over the last one to two decades, except Cu, that increased indistinctively.展开更多
The bioaccumulation of mercury(Hg)in aquatic ecosystem poses a potential health risk to human being and aquatic organism.Bioaccumulations by plankton represent a crucial process of Hg transfer from water to aquatic fo...The bioaccumulation of mercury(Hg)in aquatic ecosystem poses a potential health risk to human being and aquatic organism.Bioaccumulations by plankton represent a crucial process of Hg transfer from water to aquatic food chain.However,the current understanding of major factors affecting Hg accumulation by plankton is inadequate.In this study,a data set of 89 aquatic ecosystems worldwide,including inland water,nearshore water and open sea,was established.Key factors influencing plankton Hg bioaccumulation(i.e.,plankton species,cell sizes and biomasses)were discussed.The results indicated that total Hg(THg)and methylmercury(MeHg)concentrations in plankton in inland waters were significantly higher than those in nearshore waters and open seas.Bioaccumulation factors for the logarithm of THg and MeHg of phytoplankton were 2.4–6.0 and 2.6–6.7 L/kg,respectively,in all aquatic ecosystems.They could be further biomagnified by a factor of 2.1–15.1 and 5.3–28.2 from phytoplankton to zooplankton.Higher MeHg concentrations were observed with the increases of cell size for both phyto-and zooplankton.A contrasting trend was observed between the plankton biomasses and BAF_(MeHg),with a positive relationship for zooplankton and a negative relationship for phytoplankton.Plankton physiologic traits impose constraints on the rates of nutrients and contaminants obtaining process from water.Nowadays,many aquatic ecosystems are facing rapid shifts in nutrient compositions.We suggested that these potential influences on the growth and composition of plankton should be incorporated in future aquatic Hg modeling and ecological risk assessments.展开更多
A 6-week feeding trial was carried out to evaluate the effects of dietary vitamin E(DL-a-tocopheryl acetate, TA) on growth and mercury(Hg) accumulation in juvenile olive flounder(Paralichthys olivaceus)treated with me...A 6-week feeding trial was carried out to evaluate the effects of dietary vitamin E(DL-a-tocopheryl acetate, TA) on growth and mercury(Hg) accumulation in juvenile olive flounder(Paralichthys olivaceus)treated with mercuric chloride(HgCl_2). Vitamin E and HgCl_2 were added to the semi-purified basal diet.Six semi-purified diets in a 2 × 3 factorial design were formulated to contain 2 levels of Hg(0 or 20 mg HgCl_2/kg diet) and 3 levels of vitamin E(0, 100, or 200 mg TA/kg diet). Experimental fish(n = 360,9.99 ± 0.15 g) were randomly allocated into 30-L tanks at a density of 20 fish per tank with 3 replicates in each treatment and were fed twice a day. At the end of the feeding trial, dietary Hg depressed the growth performances in terms of weight gain(WG), specific growth rate(SGR), feed efficiency(FE) and protein efficiency ratio(PER) in fish, while fish fed the diets supplemented with vitamin E showed significant growth improvement in both presence and absence of HgCl_2 in the diets(P < 0.05). Survival rate was not affected in fish fed the experimental diets. Whole body compositions of fish such as lipid and moisture contents were influenced by dietary vitamin E supplementation. Total Hg contents of muscle, liver and kidney tissues were significantly reduced in fish fed diets supplemented with vitamin E(P< 0.05), while the two-way ANOVA showed that increasing Hg concentration has resulted in a reduction in vitamin E.Whole body fatty acids of fish like eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) contents were decreased by dietary Hg. However, supplementation of dietary vitamin E improved the a-linolenic acid(ALA) and EPA contents in fish. Our results suggest that dietary supplementation of vitamin E has potential effects on growth improvement and ameliorating inorganic Hg bioaccumulation in juvenile olive flounder.展开更多
文摘Urban wastewater contains various pollutants, with heavy metals being common, posing risks to the environment and public health, especially when used for irrigation in agricultural systems. This study aimed to assess the total and bioavailable content of Pb and Cr in agricultural soil irrigated with wastewater and their accumulation in alfalfa crops. Five alfalfa sites were sampled, and ten surface soil samples were collected from the top 30 cm of each plot. Plant samples were also collected at each sampling point. A composite sample of irrigation water from the main channels was also collected and prepared. The concentration of heavy metals was determined using atomic absorption spectrophotometry. The results revealed concentrations of Pb and Cr (VI) in the irrigation water above the maximum permissible limits according to environmental regulations. The soil had high organic matter content, neutral pH, elevated electrical conductivity (EC), and Pb and Cr contents of up to 103 and 89 mg/kg, respectively. In alfalfa tissues, Pb and Cr concentrations were recorded at 26 mg/kg and 4.6 mg/kg, respectively (Cr (VI), with lower concentrations observed in the roots. Cr (VI) was higher at all sites, with ranges from 2.25 to 43.56, while lead (Pb) had an AR ranging from 0.64 to 27.04. The Pb presented a mean of 1.45 of the Bioaccumulation factor values, which can be considered a metal-accumulating plant.
基金supported by the earmarked fund for the Modern Agro-Industry Technology Research System (CARS-47)the Program of Shandong Leading Talent (No.LJNY2015002)the AoShan Scientific and Technological Innovation Project which was financially backed by Qingdao National Laboratory for Marine Science and Technology (No.2015ASKJ02)
文摘Intensive use of sulfamethazine(SM_2) in aquaculture has resulted in some detrimental effects to non-targeted organisms. In order to assess its potential ecological risk, it is crucial to have a good understanding on the bioaccumulation and biodegradation of SM_2 in Chlorella pyrenoidosa. The microalgae were treated with 2, 4, and 8 mg L^(-1) of sulfamethazine for 13 days, respectively, showing that the inhibition effects of sulfamethazine on the growth of Chlorella pyrenoidosa increased progressively as the concentrations of sulfamethazine increasing from 2 to 8 mg L^(-1). The peak concentrations of sulfamethazine accumulated in C. pyrenoidosa were 0.225, 0.325, and 0.596 ng per mg FW on day 13 for three treatment groups, respectively, showing a great ability to deplete sulfamethazine from the culture media. On day 13, the percentages of biotic degradation were 48.45%, 60.21% and 69.93%, respectively. The EC_(50) of 10.05 mg L^(-1) was derived which showed no significant risk for C. pyrenoidosa with a calculated risk quotient < 1. The activities of superoxide dismutase and catalase increased progressively in response to sulfamethazine and showed a positive correlation to the treatment concentrations. The highest superoxide dismutase activity was achieved at the concentration of 8 mg L^(-1) after 2 d of exposure, which was 1.89 folds higher than that of the control. The activity of catalase has a similar pattern to that of superoxide dismutase with the maximum activity achieved at day 2, which was 3.11 folds higher compared to that of the control. In contrast to superoxide dismutase and catalase, the maximum glutathione S-transferase activity was observed at day 6, showing 2.2 folds higher than that of the control.
文摘Bioaccumulation of heavy metals in tea marketed in Nigeria was investigated. Four major and most consumed brand of tea were selected for the present study. Both aqueous and dry methods were used. Total contents of metal were determined by digesting 1g of each brand using a mixture (3:1) concentrated nitric acid (NNO3) and hypochlorous acid (HCLO4). The second method involved hot water extract of tea samples. After boiling and filtration, the residue was evaporated to near dryness and digested with concentrated HNO3 and HCLO4 as described above. Results indicate that Zn, Cd, Cu, and Pb were present in lowest concentrations in ascending order for which there were two significant differences between the four sources of samples. The general characteristics of heavy metal concentrations in aqueous extract showed high level of Fe and Mg in a descending order. Going by the correlation study of our result indicates that there is no significant relationship between the two elements of Fe and Mg, though, the numerical values of the two elements varied widely among the samples. These differences may have major impact on human health. However, the beneficial effects of tea are in a fairly narrow concentration range between the essential and the toxic level. In conclusion, the variations in heavy metals content of tea brands may be due to geographical, seasonal changes and the chemical characteristics of the growing regions.
文摘The studies on bioaccumulation and distribution of the plant growth regulator multi - effect triazole( MET) in the fish (Carassias auratus) and Daphnia (D. magna) showed that the bioaccumulation factor(BCF) was in positive correlation to the lipid content
文摘This study was aim to determined the levels of some heavy metals in the gills, liver, stomach, kidney, bones and flesh of four fish species (Tilapia zilli, Clarias anguillaris, Synodentis budgetti and Oreochronmis niloticus) collected at River Benue in Vinikilang, Adamawa State, Nigeria for analysis of Cu, Zn, Co, Mn, Fe, Cr, Cd, Ni and Pb. These metals were chosen because at higher concentrations there might be toxic to the fish and by extension humans that depends on such fish as food. The concentrations of the metals were carried out using Flame Atomic Absorption Spectrophotometer (AAS, Unicam 969). Large differences in trace metal concentrations were observed between different tissues within each fish. The highest concentration of Fe (12.65 μg/g) was recorded in gill of Synodentis budgetti, while the lowest value of 0.68 μg/g was recorded in the flesh of Oreochronmis niloticus. The liver of Synodentis budgetti accumulates significant higher levels of Mn and Cd than other species;Fe and Zn was highest in the stomach of Tilapia zilli, while Clarias angullaris shows more of Cr, Pb, Cd and Co. The stomach of Synodentis budgetti accumulate significant higher levels of Fe than other species;Zn was highest in the stomach of Tilapia zilli, while Clarias angullaris shows more of Mn, Cr, Cu, Cd and Pb. Similarly, the bone of Synodentis budgettiaccumulates significant higher levels of Mn and Cd than other species;Zn and Fe were highest in the bone of Tilapia zilli, while Clarias angullaris shows more of Cr, Pb, Ni, and Co. The highest levels of Fe (12.65 μg/g) observed in this study was recorded in the gill of Synodentis budgetti and it was below the high residue concentrations of Fe (34 - 107 ppm) in fish samples. Based on the above results, it can therefore be concluded that metals bioaccumulation in the entire fish species study did not exceeds the permissible limits set for heavy metals by FAO, FEPA and WHO.
文摘The prevailing hypothesis, which states that the uptake of HOCs by phytoplankton is controlled by the compound’s lipophilicity (Kow) was tested. The approach taken was to determine the factors that controlled the uptake of PCBs by phytoplankton under controlled laboratory conditions, and to develop a model that would describe bioaccumulation of PCBs in phytoplankton.The results demonstrate a relationship of BAF to Kow and to phytoplankton surface properties, as well as the data presented here, support the hypothesis that the mechanism of HOC uptake is a rapid surface sorption followed by a slower transfer into lipids in the cell matrix. The work on the kinetics of uptake indicates that equilibrium is reached slowly and that the rate of uptake is of similar magnitude as phytoplankton growth under normal field conditions.Thus a critical factor that controls the bioaccumulation of HOCs reach equilibrium in phytoplankton itself.
文摘Objective:To investigate the level of heavy metals(Cu,Zn,Fe Mn Ni,Pb and Cd) in muscles,gills and liver tissue of Croaker fish from oil spilled rivers of Bonny and Finima,Niger Delta region,Nigeria.Methods:Twenty four Croacker fishes(Genyonemus lineatus) weighing between 250 and 260 g and 24–26 cm length were collected from each sampling sites(Bonny and finima rivers).The frozen fishes were thawed and dried at 105C until they reach a constant weight.The dried samples were homogenized and digested with 10 ml tri-acid mixture(HNO3:HCl O4:H2SO4),and then the digested samples were diluted to 100 ml with deionized water.Heavy metals(Cu,Ni,Zn,Pb,Mn,Iron Fe,and Cd) concentrations were determined by atomic absorption spectrophotometer.Results:Our results revealed that concentrations and distribution patterns of all heavy metals studied varied significantly(P < 0.05) amongst the fish tissues analyzed and sampling sites.Moreover,liver tissue of fish caught from Finima creek accumulated the highest concentrations of Cu(52.64 ± 3.01 mg/g dry wt),Zn(166.50 ± 6.45 mg/g dry wt)and Fe(801.50 ± 14.15 mg/g dry wt) in comparison to the liver of fish caught from Bonny river in which the levels of Cu,Zn and Fe were(45.00 ± 2.79),(49.90 ± 2.91) and(216 ± 6.11 mg/g dry wt),respectively.In addition,Mn,Ni,Pb and Cd exhibited their highest concentrations in gills from both locations.As expected,muscle tissue contained the least concentrations of all metals investigated from both sampling sites.Furthermore,all the metals investigated exhibited highest concentration in fish collected from Finima creek.These abnormal high level heavy metals accumulation observed in this location could be linked to the frequent crude oil spills as well as industrial activity around the area which might get discharged into Finima creek.In general,the mean concentrations of some toxic heavy metals investigated exceed the recommended maximum permissible limits set by the Joint FAO/WHO committee.However,some metals are within the acceptable limits.Conclusions:In conclusion,our data showed the abnormal higher concentration of these metals and this might be toxic to the fish and other aquatic organisms directly or by extension to humans that frequently consumed such contaminated fishes.
基金Supported by the Natural Science Foundation of China (30170162)Wuxi Science and Technology Bureau Foundation (CL045001)
文摘Etrazine is one of the most widely used herbicides in China and the world.Acute and chronic toxicity tests were carried out to assess the possible toxicity effect of atrazine on crucian carp(Carassius auratus).Results showed that 96 h LC50 of atrazine to Carassius auratus was 105.94 mg L-1.The enzyme activities of superoxide dismutase(SOD),catalase(CAT) and glutathione-S-transferases(GST) in kidney of Carassius auratus were all influenced by atraizine,and CAT was more sensitive to atrazine compared with SOD and GST.Atrazine residues in kidney of Carassius auratus reached the stable state at day 19,and the bioaccumulation factors(BAF) of atrazine in kidney of Carassius auratus treated with 1.0 mg L-1 and 10.0 mg L-1 atrazine were 8.3 and 4.4,respectively.The research demonstrated that atrazine could cause oxidative stress to fish kidney,but atrazine was not easy to accumulate in Carassius auratus kidney,and the antioxidant enzymes could be used as biomarker to the early detection of pollution.
文摘Concentration of Cadmium, Copper, Lead, Zinc and Mercury were determined in the muscles, gills and liver of ten fish species (Epinephelus areolatus, Epinephelus radiates, Anthias squamipinnis, Plectorhinchus chaetodonoides, Snubnose emperor, Dicentrarchus labrax, Acanthopagrus bifasciatus, lutjanus kasmira, lutjanus ehrenbergii and Acanthurus gahhm) as well as three specimens of crustaceans (Metapenaeus dalli, Panulirus penicillatus and Portunus petagicus) and two Specimens of squids (Parateuthis tunicate and Chtenopteryx sicula) collected from Jeddah coastal water during 2014. The obtained results declared that, the average concentrations of heavy metals were as follows: Cd (0.098, 0.20, 0.106), Cu (0.358, 0.327, 1.536), Pb (0.3, 0.257, 0.196), Zn (3.00, 7.390, 4.999) μg/g wet weight in the muscle, gills and liver, respectively. While, the concentration of Hg was invariably undetectable in all samples of different organs of the collected fish species. The average concentration of Cd, Cu, Pb, Zn and Hg in the soft part of the investigated crustaceans (Metapenaeus dalli, Panulirus penicillatus and Portunus petagicus) and squids (Parateuthis tunicate and Chtenopteryx sicula) were relatively higher compared with the muscle tissues in the examined fish species. The results of bioconcentration factor (BCFs) indicated that among examined metals Zn was the most readily absorbed by fish and the highest BAFs for examined fish species were determined in gill of Snubnose emperor.
文摘The use of biomarkers has become an important tool for modern environmental assessment as they can help to predict pollutants involved in the monitoring program. Here I present data on bioaccumulation, biochemical and tissues biomarkers in Nile tilapia as early warning indicators of river Nile pollution. Nile tilapia sampled from downstream sites accumulated higher levels of all the detected heavy metals than those collected from upstream sites. Heavy metal residues in the tissues of Nile tilapia exhibited different patterns of accumulation and distribution among the selected tissues. Remarkable alterations in the activities of glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) in the tissues of Nile tilapia were detected. These alterations were followed, in the present study, by the occurrence of histological lesions in liver and gill tissues of fish collected from the same sites. Alterations in bioaccumulation patterns, in enzyme activities and in histology go in parallel with the elevation in the levels of water chemical parameters detected in the downstream sites as a result of pollution stress in these areas. These results provide evidence that bioaccumulation, biochemical and tissues biomarkers can be sensitive indicators of exposure to mixed pollutants in surface waters.
文摘Several mechanisms are developed by the microorganisms to tolerate few high concentrations of heavy metals. One of these mechanisms dependent upon anabolic and catabolic energy of microorganisms is the bioaccumulation of heavy metals. In present work, approximately four varieties of bacteria have been isolated from the ash dyke sample of four thermal power plants of Chhattisgarh, i.e., Bharat Aluminium Company (BALCO), Chhattisgarh State Electricity Board (CSEB), Korba, Thermal Power Cooperation (NTPC), Bilaspur and KSK Akaltara, Chattisgarh. Out of one hundred fifty isolates, three were capable to grow in varying concentration of heavy metals. The strains were tested for their tolerance against six different types of heavy metals dominant in the ash samples viz. Pb, Hg, Ni, Co, Cu, Mn. Their maximum resistance existed up to 0.6mM/ml of the above mentioned different metals under lab standard conditions. Three isolates are found suitable for the multiple metal resistance ability viz SM2, SM3, and SM12. These are categorized as Bacillus cereus (SM2, SM3), and Bacillus subtilis (SM12) after performing 16S rDNA sequencing.
文摘In the present study, the two lakes, Vengaiah lake (Lake A-Sewage polluted receiving discharge from storm water drain) and Yellamallappa Chetty lake (Lake B-Industrially polluted) situated near Krishnarajpuram-Hoskote taluk, Bangalore, Karnataka were selected for analysis of trace metals viz., arsenic, aluminium, cadmium, lead, mercury, iron, copper and zinc in water samples. Muscle and gill tissues of freshwater fish Labeo rohita reared in these water bodies were analysed for bioaccumulation of trace metals. Hebbal fish farm was considered as a reference site (Control site) for water and fish samples. Trace metals were analysed by atomic absorption spectroscopy and values were compared with those recommended by FAO/WHO in water and fish samples. Trace metals such as Al, As and Hg were detected in the water sampled from lake B which is attributed to the differences in the sources of pollutants. Fish tissues viz., muscle and gills sampled from Lake B exhibited high concentration of Al, Pb and Cd content showing a positive correlation with their concentration in water samples. The remaining metals as Cu, Zn and Fe were detected in water sampled from all water bodies and also in the fish tissues. Gills exhibited higher concentration of metals in fish from lake B. Bioaccumulation of these trace metals in fish tissues may cause potential danger to human health when consumed on regular basis. Thus necessary remedial measures are required to combat water contamination and its management keeping in view the aquatic ecosystem and public health. Values were statistically significant at P < 0.0001.
文摘The roads in correlation with the traffic linked to their existences are at the origin of the emission of numerous polluting substances likely to induce disturbances of the growth and the behavioral changes in the organisms living in their vicinities. The purpose of this study is to analyze the growth and capacity accumulation of a common earthworm species (Millsonia omodeoi) in Cu, Cr, Ni, Pb and Zn in soils along a main road called “Autoroute du Nord” in C?te d’Ivoire. Thus, the earthworms were harvested in soils from a distance of 0 m (just after the sidewalk) to a distance of 200 m from the toll highway and in a control soil sampled in Lamto reserve (C?te d’Ivoire). The study was carried out in the soil laboratory at the ecological station of Lamto reserve. The Ford-Walford technique was used to determine the model and parameters most appropriated for describing the growth of earthworms. A pairwise comparison of the growth parameters was carried out using the Kruskal-Wallis test with the STATISTICA 7.1 software. The heavy metals contained in the cultivated soils and earthworms were detected and quantified using a Scanning Electron Micro-scope (MEB FEG Supra 40 VP Zeiss) and an Atomic Absorption Spectrometer SPECTRA 110 (VARIAN). The capacity accumulation of heavy metals in earthworm was determined by the bioaccumulation factor (BAF) calculation. The results of this study showed that Gompertz is the most appropriated model to describe the growth of M. omodeoi. The life cycle of M. omodeoi shows that this earthworm adopts a K type demographic strategy. Cu is the most accumulated heavy metals in M. omodeoi, when Cr is the least accumulated. Concerning heavy metal content in the earthworms, it decreases while moving away from the pavement. These results highlight a possibility of choice of M. omodeoi as 1) indicators of heavy metals pollution and 2) target of biological organisms for environmental impact studies.
基金the Special Fund for AgroScientific Research in the Public Interest of China(No.201503108)the Science and Technology Project of Hunan Province(No.2017WK2091)。
文摘Dietary uptake is the major way that inorganic arsenic(iAs)enters into benthic fish;however,the metabolic process of dietborne i As in fish muscle following chronic exposure remains unclear.This was a 40-day study on chronic dietborne i As[arsenite(AsⅢ)and arsenate(AsⅤ)]exposure in the benthic freshwater food fish,the crucian carp(Carassius auratus),which determined the temporal profiles of iAs metabolism and toxicokinetics during exposure.We found that an adaptive response occurred in the fish body after iAs dietary exposure,which was associated with decreased As accumulation and increased As transformation into a non-toxic As form(arsenobetaine).The bioavailability of dietary AsⅢwas lower than that of AsⅤ,probably because AsⅢhas a lower ability to pass through fish tissues.Dietary AsⅤexhibited a high potential for transformation into AsⅢspecies,which then accumulated in fish muscle.The largely produced AsⅢconsidered more toxic at the earlier stage of AsⅤexposure should attract sufficient attention to human exposure assessment.Therefore,the pristine As species and exposure duration had significant effects on As bioaccumulation and biotransformation in fish.The behavior determined for dietborne arsenic in food fish is crucial for not only arsenic ecotoxicology but also food safety.
文摘In this paper,we report the bioaccumulation and transformation of cadmium (Cd) by Phaeodactylum tricornutum in the presence of ethylenediamine tetra acetic acid (EDTA) and cysteine (Cys). Both EDTA and Cys can alleviate the toxicity of Cd to P. tricornutum. Short term intracellular uptake and extracellular adsorption experiments using ICP-MS indicated that the amounts of Cd accumulated on the cell surface of P. tricornutum and inside the cell decreased along with the increase of EDTA concentration,which conformed to the prediction of the Free Ion Activity Model (FIAM). However,extracellular adsorption of Cd increased at first and then decreased along with the increase in the concentration of Cys,while intracellular uptake increased under Cys concentrations from the blank value to 4.45 μmol/L,and then tended to remain at the same level when the Cys concentration was greater than 4.45 μmol/L,and this deviated remarkably from the FIAM. The interactions of Cd with _Si_OH,_C_OH and NH2(CO) _OH on the cell wall were confirmed using FT-IR and XPS studies. The results obtained using HPLC of the phytochelatins (PCs) produced by P. tricornutum under CdCl2,Cd_EDTA and Cd_Cys stress suggested that the main reason for the different effects of EDTA and Cys on the bioaccumulation and transformation of Cd by P. tricornutum was that Cys is not only a complexing ligand to Cd,as is EDTA,but also it is a precursor of the intracellular synthesizing PCs participating in the cellular defense mechanism against Cd. Furthermore,the discovery of in vivo PCs and oxidized_PCs as well as Cd-PC2 in P. tricornutum using ESI-IT-MS provided the evidence for deactivation of Cd by the PCs,reducing Cd-toxicity to P. tricornutum.
基金jointly supported by the National Natural Science Foundation of China (Nos. 51622901 , 51709225 )the Young Scientific Research Innovation Team Project of Xi'an University of Technology (No. 104/256051715 )。
文摘Trace metal contamination in water and bioaccumulation in aquatic organisms are human health risks of increasing concern. However, the bioaccumulation of trace metals in the organs of the mussel Cristaria plicata in Dongting Lake, China and the human health risks of mussel consumption are largely unknown. We investigated the concentrations of 15 trace metals and metalloids in surface water, sediments, and C. plicata organs(foot, gill, mantle, and visceral mass) and quantified the bioaccumulation and human health risk of these trace metals in specimens collected from Dongting Lake. The concentrations of most metals in surface water exceeded previously published background values. In contrast, the concentrations of most metals in sediments showed a decreasing trend. Overall, the metal concentrations in the gill and visceral masses of C. plicata were higher than those in the foot and mantle, and higher bioaccumulation capacities were observed for essential metals than for nonessential metals. The mean concentrations of the trace elements Zn, Pb, Cd, As, Cu, and Cr in C. plicata foot samples were lower than the threshold values established by international and Chinese organizations. The estimated daily intake(EDI) values of the essential metal Mn in C. plicata foot was higher than the recommended tolerable daily intake(TDI) values for juveniles. Only Mn for juveniles and As for both juveniles and adults may pose noncarcinogenic health risks through foot consumption. The hazard index(HI) values for adults and juveniles were higher than 1, suggesting significant risks of noncarcinogenic effects to humans by exposure to multiple metals.
基金supported by the National Natural Science Foundation of China (Nos. 41603103 and 41373113)the Fundamental Research Funds for the Central Universities (No. XDJK2017B035)
文摘As a global toxic pollutant,mercury(Hg)bioaccumulation within food chain could be influenced by human disturbance.Ten typical fish species were collected from Changshou Lake,an artificial lake used to carry out cage fish culture,to investigate the C/N isotopic compositions and Hg bioaccumulation in fish.The results showed that the total Hg(THg)and methylmercury(MeHg)levels in fish muscles((56.03±43.96)and(32.35±29.57)ng/g,wet weight),comparable with those in most studies in China,were significantly lower than the international marketing limit(0.5 mg/kg).Past human input for cage culture in this lake led to abnormal^(15)N enrichment in food chain,as the quantitative trophic levels based onδ^(15)N were different with that classified by feeding behaviors.This phenomenon subsequently demonstrated that it should be considered thoughtfully with respect to the application of the traditional method for understanding Hg bioaccumulation power by the slope of log_(10)[Hg]withδ^(15)N regression in specific water body(i.e.,Changshou Lake).In addition,no significant linear correlation between Hg and body weight or length of some fish species was observed,suggesting that the fish growth in the eutrophic environment was disproportionate with Hg bioaccumulation,and fish length or weight was not the main factor affecting Hg transfer with food web.The occurrence of human disturbance in aquatic system presents a challenge to a better understanding of the Hg bioaccumulation and biomagnification within the food chain.
基金supported by the Science and Technology Program of Guangzhou,China (No. 201707010219)the National Natural Science Foundation of China (No. 41877295)the Project of China Geological Survey (No. DD20190627)。
文摘Trace metal(Cr, Ni, Cu, Zn, Cd and Pb) exposures, distribution and bioaccumulation were investigated in marine organisms from Guangdong coastal regions, South China. The results showed that all of the selected metals were observed in marine organisms with a predomination of Cu and Zn. The metal exposure levels exhibited obvious variations between species with the decreasing order of crab > shellfish > shrimp > fish. The higher metals enrichment seen in shellfish and crab species primarily attributed to their living habits and the higher sediment background values of trace metals. Endpoint bioaccumulation factor(BAFfd) was used to characterize the bioaccumulation potentials of marine organisms to trace metals, of which Cu and Zn were the most accumulated elements. The exposure of trace metals in the cultured organisms was far lower than those in wild marine organisms, which is probably due to the effect of growth dilution. Comparisons with previous studies demonstrated that the concentration profiles of most trace metals declined over the last one to two decades, except Cu, that increased indistinctively.
基金funded by National Natural Science Foundation of China(Grant Nos.41977324 and 41630748)the Natural Science Foundation of Tianjin(No.20JCYBJC01080).
文摘The bioaccumulation of mercury(Hg)in aquatic ecosystem poses a potential health risk to human being and aquatic organism.Bioaccumulations by plankton represent a crucial process of Hg transfer from water to aquatic food chain.However,the current understanding of major factors affecting Hg accumulation by plankton is inadequate.In this study,a data set of 89 aquatic ecosystems worldwide,including inland water,nearshore water and open sea,was established.Key factors influencing plankton Hg bioaccumulation(i.e.,plankton species,cell sizes and biomasses)were discussed.The results indicated that total Hg(THg)and methylmercury(MeHg)concentrations in plankton in inland waters were significantly higher than those in nearshore waters and open seas.Bioaccumulation factors for the logarithm of THg and MeHg of phytoplankton were 2.4–6.0 and 2.6–6.7 L/kg,respectively,in all aquatic ecosystems.They could be further biomagnified by a factor of 2.1–15.1 and 5.3–28.2 from phytoplankton to zooplankton.Higher MeHg concentrations were observed with the increases of cell size for both phyto-and zooplankton.A contrasting trend was observed between the plankton biomasses and BAF_(MeHg),with a positive relationship for zooplankton and a negative relationship for phytoplankton.Plankton physiologic traits impose constraints on the rates of nutrients and contaminants obtaining process from water.Nowadays,many aquatic ecosystems are facing rapid shifts in nutrient compositions.We suggested that these potential influences on the growth and composition of plankton should be incorporated in future aquatic Hg modeling and ecological risk assessments.
基金supported by the National Research Foundation (NRF)funded by the Korean government (MOST)(NRF2011-0016221)Feeds and Foods Nutrition Research Center, Pukyong National University, Busan, Republic of Korea
文摘A 6-week feeding trial was carried out to evaluate the effects of dietary vitamin E(DL-a-tocopheryl acetate, TA) on growth and mercury(Hg) accumulation in juvenile olive flounder(Paralichthys olivaceus)treated with mercuric chloride(HgCl_2). Vitamin E and HgCl_2 were added to the semi-purified basal diet.Six semi-purified diets in a 2 × 3 factorial design were formulated to contain 2 levels of Hg(0 or 20 mg HgCl_2/kg diet) and 3 levels of vitamin E(0, 100, or 200 mg TA/kg diet). Experimental fish(n = 360,9.99 ± 0.15 g) were randomly allocated into 30-L tanks at a density of 20 fish per tank with 3 replicates in each treatment and were fed twice a day. At the end of the feeding trial, dietary Hg depressed the growth performances in terms of weight gain(WG), specific growth rate(SGR), feed efficiency(FE) and protein efficiency ratio(PER) in fish, while fish fed the diets supplemented with vitamin E showed significant growth improvement in both presence and absence of HgCl_2 in the diets(P < 0.05). Survival rate was not affected in fish fed the experimental diets. Whole body compositions of fish such as lipid and moisture contents were influenced by dietary vitamin E supplementation. Total Hg contents of muscle, liver and kidney tissues were significantly reduced in fish fed diets supplemented with vitamin E(P< 0.05), while the two-way ANOVA showed that increasing Hg concentration has resulted in a reduction in vitamin E.Whole body fatty acids of fish like eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) contents were decreased by dietary Hg. However, supplementation of dietary vitamin E improved the a-linolenic acid(ALA) and EPA contents in fish. Our results suggest that dietary supplementation of vitamin E has potential effects on growth improvement and ameliorating inorganic Hg bioaccumulation in juvenile olive flounder.
