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 heavy metal bioaccumulation levels of 13 species of mushrooms were studied. 13 different species of wild mush-rooms growing in China were analyzed for Cu, Zn, Pb, Cd, and As. Contents of Cu, Zn, Cd and Pb in mushr...The heavy metal bioaccumulation levels of 13 species of mushrooms were studied. 13 different species of wild mush-rooms growing in China were analyzed for Cu, Zn, Pb, Cd, and As. Contents of Cu, Zn, Cd and Pb in mushroom and Cu, Zn in soil were tested by atomic absorption spectrometer (AAS), and As in samples by atomic fluorescent light (AFL). Contents of Cd and Pb in soil were analyzed by graphite furnace AAS. The results showed that contents of Cu, Pb, Cd, and As in Termitomyces microcarpus were the highest in the tested mushroom samples, which were 135.00, 13.28, 65.30, and 1.60 mg·kg-1 (dry biomass) respectively, and the corresponding bioconcentration factor (BCF) for Cu and Cd was 57 and 1 674 separately, which was the highest data in 13 mushroom species. The capability of Boletus griseus for Cd accumulation was very strong with BCF of 300. when people consume the wild edible mushrooms, contents of Cd and Pb should be greatly considered.展开更多
To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (c...To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (control, 5, 40, and 160 μg/L Hg) for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, bone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation (LPO), which was also tissue-specific and dosedependent. As Hg concentration increased, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly, whereas glutathione S-transferase (GST) activity and glutathione (GSH) levels decreased significantly in the gills. SOD and glutathione peroxidase (GPx) activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder.展开更多
The bioaccumulation and toxicity of heavy metals were reviewed with special reference to microalgae, the key compo- nent of the food web in aquatic ecosystems. Heavy metals enter algal cells either by means of active ...The bioaccumulation and toxicity of heavy metals were reviewed with special reference to microalgae, the key compo- nent of the food web in aquatic ecosystems. Heavy metals enter algal cells either by means of active transport or by endocytosis through chelating proteins and affect various physiological and biochemical processes of the algae. The toxicity primarily results from their binding to the sulphydryl groups in proteins or disrupting protein structure or displacing essential elements. Metals can break the oxidative balance of the algae, inducing antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX). The amount of oxidized proteins and lipids in the algal cells thus indicates the severity of the stress. Algal tolerance to heavy metal is highly dependent upon the defense response against the probable oxidative damages. Pro- duction of binding factors and proteins, exclusion of metals from cells by ion-selective transporters and excretion or compartmen- talization have been suggested with regard to reducing heavy metal toxicity. However, a comprehensive description on the mecha- nisms underlining metal toxicity of microalgae and gaining tolerance is yet to be elaborated.展开更多
Contamination of aquatic ecosystems with heavy metals has been receiving increased worldwide attention due to their harmful effects on human health and other organisms in the environment.Most of the studies dealing wi...Contamination of aquatic ecosystems with heavy metals has been receiving increased worldwide attention due to their harmful effects on human health and other organisms in the environment.Most of the studies dealing with toxic effects of metals deal with single metal species,while the aquatic organisms are typically exposed to mixtures of metals.Hence,in order to provide data supporting the usefulness of freshwater fish as indicators of heavy metal pollution,it has been proposed in the present study to investigate the bioaccumulation and depuration of chromium in the selected organs of freshwater fingerlings Cirrhinus mrigala,individually and in binary solutions with nickel.The results show that the kidney is a target organ for chromium accumulation,which implies that it is also the "critical" organ for toxic symptoms.The results further show that accumulation of nickel in all the tissues of C.mrigala is higher than that of chromium.In addition,the metal accumulations of the binary mixtures of chromium and nickel are substantially higher than those of the individual metals,indicating synergistic interactions between the two metals.Theoretically the simplest explanation for an additive joint action of toxicants in a mixture is that they act in a qualitatively similar way.The observed data suggest that C.mrigala could be suitable monitoring organisms to study the bioavailability of water-bound metals in freshwater habitats.展开更多
Accumulation of heavy metals from various oxides with adsorbed cadmium by wetland plant Phragmites australis was studied to evaluate the fate of heavy metals in the sediment of constructed wetlands. Hoagland solution ...Accumulation of heavy metals from various oxides with adsorbed cadmium by wetland plant Phragmites australis was studied to evaluate the fate of heavy metals in the sediment of constructed wetlands. Hoagland solution was used as nutrition supply, and single metal oxide with adsorbed cadmium was applied as contaminant to study the accumulation characteristics of cadmium and the substrate metals by P. australis. After 45-d treatment, the bioaccumulation degree in root followed the order: Al(OH)3 > Al2O3 > Fe3O4 > MnO2 > FeOOH. Heavy metals absorbed by P. australis were largely immobilized by the roots with little translocation to aboveground parts.展开更多
Mercury (Hg) concentrations in the tissues (muscle, stomach, liver, gills, skin, and gonads) of five fish species (mullet Liza haematocheilus, flathead fish Platycephalus indicus, sea bass Lateolabrax japonicus, macke...Mercury (Hg) concentrations in the tissues (muscle, stomach, liver, gills, skin, and gonads) of five fish species (mullet Liza haematocheilus, flathead fish Platycephalus indicus, sea bass Lateolabrax japonicus, mackerel Scomberomorus niphonius and silver pomfret Pampus argenteus) collected from Laizhou Bay in the Bohai Sea of China were investigated. The results indicate that Hg bioaccumulation in the five fish was tissue- specific, with the highest levels in the muscle and liver, followed by the stomach and gonads. The lowest levels were found in the gills and skin. Fish at higher trophic levels (flathead fish and sea bass) exhibited higher Hg concentrations than consumers at lower trophic levels. Mercury bioaccumulation tended to be positively correlated with fish length in mullet, silver pomfret, mackerel, and flathead fish, but was negatively correlated with fish length in sea bass. The Hg concentrations in the muscles of all fish species in Laizhou Bay were within the permissible limits of food safety set by national and international criteria. However, the suggesting maximum consumption of sea bass is 263g per week for human health.展开更多
Through a pot culture lanthanum nitrate was applied to maize seedlings grown in a red loamy soil to investigate the physiological and toxic effects of added La on the growth of crop seedlings and La bioaccumulation to...Through a pot culture lanthanum nitrate was applied to maize seedlings grown in a red loamy soil to investigate the physiological and toxic effects of added La on the growth of crop seedlings and La bioaccumulation to help understand the environmental chemistry behaviors of rare earth element as fertilizers in soils. Compared to the control, La concentrations in shoots and especially in roots of maize seedlings increased with an increase of La in the soil. Also, with added concentrations of La≥0.75 g La kg-1 soil and≥0.05 g La kg-1 soil, the dry weight of shoots and roots of maize seedlings was significantly reduced (P≤0.05), respectively, compared with the control. Additionally, La≥0.5 g kg-1 in the soil significantly inhibited (P≤0.05) primary root elongation. Roots were more sensitive to La stress than shoots and thus could be used as a biomarker to La stress. Overall, in the red loamy soil studied, La had no significant beneficial effects on the growth of maize at the added La levels above 0.1 g kg-1 soil.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.
基金the National Natural Science Foundation of China(40741004)Program of Sichuan Bureau of Science and Technology (04SG023-006-05)Post Doctorial Program of Institute of Mountain Haz-ards and Environment, Chinese Academy of Sciences
文摘The heavy metal bioaccumulation levels of 13 species of mushrooms were studied. 13 different species of wild mush-rooms growing in China were analyzed for Cu, Zn, Pb, Cd, and As. Contents of Cu, Zn, Cd and Pb in mushroom and Cu, Zn in soil were tested by atomic absorption spectrometer (AAS), and As in samples by atomic fluorescent light (AFL). Contents of Cd and Pb in soil were analyzed by graphite furnace AAS. The results showed that contents of Cu, Pb, Cd, and As in Termitomyces microcarpus were the highest in the tested mushroom samples, which were 135.00, 13.28, 65.30, and 1.60 mg·kg-1 (dry biomass) respectively, and the corresponding bioconcentration factor (BCF) for Cu and Cd was 57 and 1 674 separately, which was the highest data in 13 mushroom species. The capability of Boletus griseus for Cd accumulation was very strong with BCF of 300. when people consume the wild edible mushrooms, contents of Cd and Pb should be greatly considered.
基金Supported by the National Natural Science Foundation of China for Creative Research Groups (No. 41121064)the National High Technology Research and Development Program of China (863 Program) (No.2009AA09Z401)+1 种基金the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q07-02)the Public Interest Research Program in Marine Industry from the State Oceanic Administration of China (No. 200905019)
文摘To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (control, 5, 40, and 160 μg/L Hg) for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, bone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation (LPO), which was also tissue-specific and dosedependent. As Hg concentration increased, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly, whereas glutathione S-transferase (GST) activity and glutathione (GSH) levels decreased significantly in the gills. SOD and glutathione peroxidase (GPx) activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder.
文摘The bioaccumulation and toxicity of heavy metals were reviewed with special reference to microalgae, the key compo- nent of the food web in aquatic ecosystems. Heavy metals enter algal cells either by means of active transport or by endocytosis through chelating proteins and affect various physiological and biochemical processes of the algae. The toxicity primarily results from their binding to the sulphydryl groups in proteins or disrupting protein structure or displacing essential elements. Metals can break the oxidative balance of the algae, inducing antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX). The amount of oxidized proteins and lipids in the algal cells thus indicates the severity of the stress. Algal tolerance to heavy metal is highly dependent upon the defense response against the probable oxidative damages. Pro- duction of binding factors and proteins, exclusion of metals from cells by ion-selective transporters and excretion or compartmen- talization have been suggested with regard to reducing heavy metal toxicity. However, a comprehensive description on the mecha- nisms underlining metal toxicity of microalgae and gaining tolerance is yet to be elaborated.
文摘Contamination of aquatic ecosystems with heavy metals has been receiving increased worldwide attention due to their harmful effects on human health and other organisms in the environment.Most of the studies dealing with toxic effects of metals deal with single metal species,while the aquatic organisms are typically exposed to mixtures of metals.Hence,in order to provide data supporting the usefulness of freshwater fish as indicators of heavy metal pollution,it has been proposed in the present study to investigate the bioaccumulation and depuration of chromium in the selected organs of freshwater fingerlings Cirrhinus mrigala,individually and in binary solutions with nickel.The results show that the kidney is a target organ for chromium accumulation,which implies that it is also the "critical" organ for toxic symptoms.The results further show that accumulation of nickel in all the tissues of C.mrigala is higher than that of chromium.In addition,the metal accumulations of the binary mixtures of chromium and nickel are substantially higher than those of the individual metals,indicating synergistic interactions between the two metals.Theoretically the simplest explanation for an additive joint action of toxicants in a mixture is that they act in a qualitatively similar way.The observed data suggest that C.mrigala could be suitable monitoring organisms to study the bioavailability of water-bound metals in freshwater habitats.
基金supported by the National Natural Sci-ence Foundation of China (No 40773076)the Ministry of Science and Technology of China through the National Basic Research Program of China (No 2009CB426301)
文摘Accumulation of heavy metals from various oxides with adsorbed cadmium by wetland plant Phragmites australis was studied to evaluate the fate of heavy metals in the sediment of constructed wetlands. Hoagland solution was used as nutrition supply, and single metal oxide with adsorbed cadmium was applied as contaminant to study the accumulation characteristics of cadmium and the substrate metals by P. australis. After 45-d treatment, the bioaccumulation degree in root followed the order: Al(OH)3 > Al2O3 > Fe3O4 > MnO2 > FeOOH. Heavy metals absorbed by P. australis were largely immobilized by the roots with little translocation to aboveground parts.
基金Supported by the National Natural Science Foundation of China for International or Regional Research Cooperation and Exchange Project(No.31061160187)the National Natural Science Foundation of China for Creative Research Group(No.41121064)
文摘Mercury (Hg) concentrations in the tissues (muscle, stomach, liver, gills, skin, and gonads) of five fish species (mullet Liza haematocheilus, flathead fish Platycephalus indicus, sea bass Lateolabrax japonicus, mackerel Scomberomorus niphonius and silver pomfret Pampus argenteus) collected from Laizhou Bay in the Bohai Sea of China were investigated. The results indicate that Hg bioaccumulation in the five fish was tissue- specific, with the highest levels in the muscle and liver, followed by the stomach and gonads. The lowest levels were found in the gills and skin. Fish at higher trophic levels (flathead fish and sea bass) exhibited higher Hg concentrations than consumers at lower trophic levels. Mercury bioaccumulation tended to be positively correlated with fish length in mullet, silver pomfret, mackerel, and flathead fish, but was negatively correlated with fish length in sea bass. The Hg concentrations in the muscles of all fish species in Laizhou Bay were within the permissible limits of food safety set by national and international criteria. However, the suggesting maximum consumption of sea bass is 263g per week for human health.
基金Project supported by the Jiangsu Provincial Natural Science Foundation of China (No.BK99034) the National Natural Science Foundation of China (No. 29890280-1)
文摘Through a pot culture lanthanum nitrate was applied to maize seedlings grown in a red loamy soil to investigate the physiological and toxic effects of added La on the growth of crop seedlings and La bioaccumulation to help understand the environmental chemistry behaviors of rare earth element as fertilizers in soils. Compared to the control, La concentrations in shoots and especially in roots of maize seedlings increased with an increase of La in the soil. Also, with added concentrations of La≥0.75 g La kg-1 soil and≥0.05 g La kg-1 soil, the dry weight of shoots and roots of maize seedlings was significantly reduced (P≤0.05), respectively, compared with the control. Additionally, La≥0.5 g kg-1 in the soil significantly inhibited (P≤0.05) primary root elongation. Roots were more sensitive to La stress than shoots and thus could be used as a biomarker to La stress. Overall, in the red loamy soil studied, La had no significant beneficial effects on the growth of maize at the added La levels above 0.1 g kg-1 soil.
