Pb Bioconcentration Research Articles

Pb Pollution Stress in Alnus cremastogyne Monitored by Antioxidant Enzymes

Lead (Pb) is a common toxic heavy metal element that can be absorbed by plant roots and enter the food chain, damaging human health. Alnus cremastogyne has a wide native range, is fast growing, has a wide range of timber uses, and has rhizomatous roots that can improve planted soils. In this study, we evaluated whether Alnus cremastogyne has the potential to remediate Pb-contaminated soils through a 6-month pot experiment in soils with different Pb concentrations (0, 50, 100, 200, and 400 mg/kg). Our results indicate that Alnus cremastogyne plant height, basal diameter, and organ biomass decreased, H2O2 and MDA content increased, and the activities of antioxidant enzymes and osmotic regulators increased and then decreased with increasing lead concentrations. The Pb bioconcentration factor of Alnus cremastogyne was less than 1 at all Pb concentrations, and Pb accumulated mainly in the root system. This indicates that Alnus cremastogyne is not a Pb-enriched plant and does not have outstanding Pb transport capacity. The growth of Alnus cremastogyne was not significantly affected at low Pb concentrations, and its plant height, basal diameter, and biomass were significantly suppressed under high Pb stress. Therefore, Alnus cremastogyne is not a suitable species for the remediation of lead-contaminated soils but can be used as a silvicultural species in environments with low lead levels.

Comparison among native floating aquatic macrophytes for bioconcentration of heavy metals

This work was aimed to show the development of a comparative study of the capability of bioindicators to reveal the presence of heavy metals among species of floating aquatic macrophytes such as Spirodela sp (giant duckweed), Pistia stratiotes (water lettuce), Salvinia sp used as a parameter for bioconcentration factors plant / sediment. We performed a simple sampling at six sites in the region of Pelotas, southern Brazil, in which it was collected sediments and plants. The plants experienced the nitric perchloric acid digestion method, while the sediment suffered pseudo total acid digestion method. The determination of Cr, Cu, Pb and Zn in the extracts was conducted by atomic absorption spectrophotometry in flame. In general, the floating aquatic macrophytes studied showed better bioconcentration factor for metals from the sediment in the following order: Cu>Zn>Pb>Cr. For copper, the figures obtained with Pistia stratiots ranged from 5.7 to 82.8. The BCF for Zn ranged from 3.0 to 11.6 and Salvinia sp. For the Pb bioconcentration factor, it ranged from 5.4 to 0.6 in Spirodela sp. The in situ study showed that all species had high bioaccumulation potential, especially Pistia stratiotes that was employed to remove copper.

Effect and Mechanism of Bicarbonate Ion on Lead Absorption in Pontederia crassipes from Karst Water

Bicarbonate ions (HCO3−) are abundant in karst water with poor lead (Pb) utilization and biodegradation. This study aimed to investigate the mechanism of HCO3− on the Pb removal efficiency and uptake ability of Pontederia crassipes (a widespread hydrophyte in the karst area) from karst water. The Pb concentration, Pontederia crassipes morphology, and functional group were detected. As the HCO3− molarity in karst water increased (3, 4, and 5 mmol/L), the removal of Pb increased (85.31%, 93.28%, and 95.16%), whereas the bioconcentration amount of Pb decreased (573, 501, and 301 mg/kg), mainly due to the insoluble PbCO3 and Pb (OH)2. The Pb bioconcentration factor was the highest (15,564) at 4 mmol/L HCO3− due to the maximum strength of cation exchange and cell wall protein C=O. High HCO3− molarities changed the variety of positive ions of cation exchange (HCO3− ≤ 4 mmol/L: Na, K, and Mg; HCO3− > 4 mmol/L: Mg and K), and relieved the breaking of roots, stomatal closure, and vascular system shrinking. Moreover, high HCO3− molarities diminished the C≡C oxidation, enlarged the displacement of SO42− and C-O, and stimulated the methyl transfer reaction and the bonding between -CH3 and Pb.

Study of content and bioconcentration of heavy metal (Pb,Hg, and Cd) in green mussels (Perna viridis) based on different sizes and ages

Green mussel (Perna viridis) has filter-feeding habits and a sessile way of life, with the main food components of plankton and organic matter in the waters. These food components can contaminate green mussels when it accumulates heavy metals. Therefore, this study aims to evaluate heavy metals content and the bioconcentration of lead (Pb), mercury (Hg), and cadmium (Cd) in green mussels based on different sizes and ages. The study was conducted on Pasaran Island, Lampung, Indonesia, and used green mussels aged 3, 5, 7 to 9 months as samples, with 2 replications. The AAS (Atomic Absorption Spectrophotometry) method was used in the analysis of Pb, Hg, and Cd, sampling technique used purposive sampling. The result showed that green mussels at different ages and sizes has impact on Pb content, while an increase of one unit of age and size of green mussels has no effect on the metal content of Hg and Cd. Furthermore, the highest bioconcentration of Pb and Hg was obtained at 9 months, while Cd was observed at 3 months. Based on the results of this study it can be concluded that the simple linear regression appropriate a functional relationship between Pb and the different ages and sizes green mussels cultivated on Pasaran Island , while heavy metals Hg and Cd appropriate with a polynomial quadratic approach and almost do not exist in the form of a functional relationship between Hg and Cd with the different ages and sizes green mussels. Even though it contains heavy metals in below the maximum limit, but care needs to be taken in addressing this phenomenon due to its nature heavy metals that can accumulate in living tissue, thus consuming green mussels containing heavy metals even in relatively small amounts is not recommended.Keywords:Filter feederSessileAccumulateOrganic matterContaminate

Distribution, speciation, and bioaccumulation of potentially toxic elements in the grey mangroves at Indian Sundarbans, in relation to vessel movements

Sundarban is the world's largest mangrove wetland and home of 4.6 million people (Indian part), whose principal mode of communication is motorized boats (ferries). This study shed light on the role played by ferry movement in the speciation (following the BCR three-step sequential extraction method), ecological impact and bioaccumulation of potentially toxic elements (PTEs) in plant tissues (root and lamina) of grey mangrove (Avicennia marina) found near the five ferry ghats (ports). One-way ANOVA showed variation in major soil parameters (silt, clay, organic carbon, pH, Electrical conductivity) and PTEs (As, Cd, Cr, Cu, Hg, and Pb) between sites. Sequential extraction revealed that Cd was present in the ‘exchangeable’ form across the sites, Pb was in the ‘reducible’ form, and the rest of the PTEs were majorly found in ‘residual’ phase. Pollution indices revealed moderate to heavy contamination and considerable potential ecological risk due to Cd. Pearson correlation statistics and concentration variations indicate a relation between Pb and ferry movement frequency in the sites. Higher bioconcentration of Pb in the roots of A. marina, indicates phytostabilization action. Translocation factor for Cd in the leaves, indicates phytoextraction by A. marina. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) showed a close association between vehicle movement and Hg, Pb, Silt fraction, electrical conductivity, Cr, and As. This study recommends regular pollution monitoring across Sundarbans, as the PTEs in sediment-plant matrix can impact the higher trophic levels, human health through possible biomagnification in the detritus food chain, and can adversely impact the existing conservation initiatives.

Intercropping of Pennisetum sinese with Lolium perenne improved phytoextraction of heavy metal from soil

In order to find the optimum planting pattern for phytoremediation of metal‐accumulating plants in heavy metal‐contaminated soils, Pennisetum sinese and Lolium perenne were intercropped or monocultured, and the plant leaf physiological indexes as well as the heavy metal contents and accumulation of the two plants were determined. The contents, accumulation, and bioconcentration of Pb, Cd, Cu, and Zn in different parts of the two plants under the intercropping method were significantly (p < 0.05) higher than those under the monoculture method. The average accumulation amounts of Pb, Cd, Cu, and Zn in P. sinese under the intercropping method are 29.51, 19.60, 182.8, and 178.2 μg/plant in leaves; 8.89, 17.99, 61.68, and 205.4 μg/plant in stems; and 8.45, 2.18, 36.35, and 47.94 μg/plant in roots, respectively. The average accumulation amounts of Pb, Cd, Cu, and Zn in L. perenne under the intercropping method are 2.30, 1.40, 23.29, and 33.34 μg/plant in shoots and 1.43, 0.42, 3.21, and 6.98 μg/plant in roots, respectively. Thus, P. sinese has higher heavy metal accumulation. Compared with the monocultured plants, the average accumulation amounts of Pb, Cd, Cu, and Zn increased in both two plants. Therefore, intercropping P. sinese and L. perenne was the optimum planting pattern for heavy metal‐contaminated soil phytoremediation, and P. sinese was more suitable for heavy metal phytoextraction from soil.

Assessing the bioconcentration of heavy metals in Nypa Palm (Nypa fruticans (Wurmb) from selected mangrove forests in Rivers State, Nigeria

The bioconcentration of Pb, Zn, Cd, Cr and Ni in tissues of Nypa palm (Nypa fruticans) was investigated during wet and dry seasons from selected mangrove forests, using the randomized complete block design. Soil and plant samples were randomly collected from plant dominated growth stations and analyzed for heavy metal content using the Perkin Elmer Analysts 200 Atomic Absorption Spectrophotometer (AAS). The results obtained showed the bio-transfer factors of heavy metals at wet season as Pb (1.08mg/kg), Zn (1.42 mg/kg), Cd (6.14 mg/kg), Cr (0.56 mg/kg) Ni (0.90 mg/kg) and dry season as Pb (0.86 mg/kg), Zn (1.15 mg/kg), Cd (5.44 mg/kg), Cr (0.66 mg/kg), Ni (1.12 mg/kg). The result further showed the bio-translocation factors of the metals at wet seasons as Pb (0.59 mg/kg), Zn (0.76 mg/kg), Cd (3.25 mg/kg), Cr (0.22 mg/kg), Ni (0.54 mg/kg) and dry season as Pb (0.64 mg/kg), Zn (1.03 mg/kg) Cd (3.07 mg/kg), Cr (0.24 mg/kg), Ni (0.61 mg/kg) respectively. Findings indicate the study plant as a hyper accumulator of Ni, Cd and Zn, and non-hyper accumulator of Cr and Pb. It is thus recommended that N. fruticans be utilized for phytoremediation of Ni, Cd and Zn in polluted mangrove ecosystem.

Heavy metal content of Pb and Cd in bandik grouper (Cephalopholis boenak) in Banten Bay, Indonesia

Banten Bay is a developing area that is used by various activities such as fishing ports, industry and hotels. Many activities in the coastal areas of Serang City and Cilegon Regency have a serious impact on the quality of waters and fishery resources along Banten Bay. This study aims to analyze and determine maximum tolerance limit for bandik grouper (C. boenak) meat and gills which are safe for consumption by adults and children. The study was conducted at six stations, namely Panjang Island and Pamujaan Besar Island during the period of May, June and July 2019. Measurement of heavy metal content on meat and gills carried out using Atomic Absorption Spectrophotometric (AAS). The content of Pb and Cd in water fluctuates. The metal content of Pb and Cd in the meat and gills of bandik grouper has exceeded the quality standards set by BPOM and FAO/WHO, and is classified as polluted mild to moderate Pb bioconcentration factor values in grouper meat ranged from 6.78-72.00 and Pb bioconcentration in grouper gills 32.86-762.61. The maximum weight of grouper meat that can be tolerated for consumption for adults is 3,5 kg/week and children 1.0 kg/week.

Biofilm-overproducing Bacillus amyloliquefaciens P29ΔsinR decreases Pb availability and uptake in lettuce in Pb-polluted soil

In this study, one mutant strain P29ΔsinR with increased biofilm production was constructed from a biofilm-producing Bacillus amyloliquefaciens strain P29. Then, the effect of strain P29 and its biofilm-overproducing mutant strain P29ΔsinR on Pb availability and accumulation in lettuce and the associated mechanisms were characterized in the Pb-contaminated soil. The live strains P29 and P29ΔsinR increased the dry masses of roots and edible tissues by 31–74% compared to the controls. The live strains P29 and P29ΔsinR reduced the Pb uptake in the roots by 36–52% and edible tissues by 24–43%, Pb bioconcentration factor by 36–52%, and rhizosphere soil available Pb content by 12–25%, respectively, compared to the controls. The live strains P29 and P29ΔsinR increased the pH, proportion of biofilm-producing bacteria by 46–154%, contents of polysaccharides by 99–139% and proteins by 32–57%, and gene relative abundances of epsC by 7.1–10.2-fold, tasA by 10.3–10.8-fold, and sipW by 6.5–26.1-fold, which were associated with biofilm formation and Pb adsorption in the rhizosphere soils, respectively, compared to the controls. Furthermore, the mutant strain P29ΔsinR showed higher ability to reduce Pb availability and uptake in lettuce and increase the pH, proportion of biofilm-producing bacteria, polysaccharide and protein contents, and relative abundances of these genes. These results showed that the biofilm-overproducing strain P29ΔsinR induced lower Pb availability and accumulation in the vegetable and more biofilm-producing bacteria, polysaccharide and protein production, and Pb-immobilizing related gene abundances in the Pb-contaminated soil.

Cadmium and lead differentially affect growth, physiology, and metal accumulation in guar (Cyamopsis tetragonoloba L.) genotypes.

Phytoremediation is a strategy to employ plants to recover high quantities of metals in the soil into the harvestable parts such as shoots and roots. High levels of Cd and lead (Pb) in the soil cause several stress symptoms in plants including a decrease in growth, reduced root growth, and carbohydrate metabolism. In this study, Saravan and HGS-867 as local landrace and Indian guar variety were selected to investigate the effect of the application of Pb (0, 40, 150, and 200 mg/l) and the cadmium (0, 25, 50, and 100 mg/l) on phonological, yield parameters, and phytoremediation assessment. The results showed that Pb translocation factor (TF) was significant in Pb×Cd and Pb×Cd×G (genotype) at p<0.01 and in Pb×G at p<0.05. Pb bioconcentration factor (BCF) was significant (p<0.01) in all treatments except Cd and Cd×G treatments. Mean comparison of the data showed that the number of flowers, leaves, and clusters in plant decreased significantly with increasing Pb content. With increasing Cd concentration, the number of branches, height, the number of seeds, clusters, and leaves for each plant decreased significantly at the level of 1%. The maximum TF was observed in Pb at 40 mg/l in the HG-867 variety. Moreover, the Saravan landrace exposed to Cd (100 mg/l) showed the highest value of BCF (Cd). The gum percentage significantly decreased with increasing concentrations of Pb and Cd. Pearson's correlation analysis indicated that plant height, number of pods/plant, root length, biomass, and pod length had a positive correlation with seed yield and a negative correlation with TF (Pb) and BCF (Pb). The results suggest that according to TF, BCF, and BAC, C. tetragonoloba L. can be effectively used as a good accumulator of toxic metals in contaminated soils.

Multivariate correlation analysis of bio-accumulation with soil properties and potential health risks of cadmium and lead in rice seeds and cabbage in pollution zones, China.

A total of 475 representative cultivated land and 435 crop samples from 11 provinces of China were collected, and lead and cadmium in 6 polluted areas by wastewater irrigation and metallurgy industry were analyzed. Rice is the major cash crop and staple food of Chinese residents. Cabbage is also a common food in Chinese daily life. Pollution levels and spatial distribution of soil, rice, and cabbage samples were illustrated on the map. In individual or multiple areas, the multivariate correlation of heavy metal's (cadmium and lead) bio-accumulation in two kinds of plants (rice seed and cabbage) and soil properties (pH, cation exchange capacity, and organic matter) was also investigated. Spearman correlation analysis showed that soil pH values and organic matter (OM) had significant effects on the uptake of Cd and Pb in rice seed: the correlation between lg Cd BCF and pH values is -0.148* (p = 0.026), and the correlation between lg Pb BCF and pH values is -0.339** (p = 0.000). The cation exchange capacity (CEC) and pH significantly impact the Cd and Pb uptake in cabbage: the correlation between lg Cd EF and pH values is -0.199* (p = 0.040), and the correlation between lg Pb EF and pH values is -0.203** (p = 0.009). The Cd and Pb bio-concentration factor BCFs of rice and cabbage decreased with the increase of pH, CEC, and OM, except that Pb BCFs increased with the increase of OM in certain areas. The BCF of Cd varied positively from Pb in cabbage, but inversely with Pb in rice significantly at the 0.01 level (two-tailed Spearman correlation analysis). For the first time, the health quotient (HQ) of Cd and Pb in different regions was also calculated and illustrated on the map. In the soil samples of different areas, average HQ values of Cd and Pb in maturity varied from 0.0003-0.0023 to 0.0051-0.0460; average HQ values of immaturity were 0.0011-0.0103 and 0.0222-0.2014. In the rice samples of different areas, average HQ values of Cd and Pb in maturity varied from 0.305-1.360 to 0.027-0.321; average HQ values of immaturity were 0.601-2.678 and 0.053-0.633. Average HQ values orders of magnitude in the cabbage samples of different areas are the same as that of rice samples, and it is 2-4 orders higher than those in soil. Average HQ values of Cd and Pb in maturity varied from 0.152-1.354 to 0.006-0.506; average HQ values of immaturity were 0.510-4.192 and 0.022-0.207. The total HQ values ingested by children were all higher than those in adults. After investigation, it was found that the total HQ value of mature plants was also higher than that of immature plants. The results of this study would be of great help to future soil remediation with similar types.

Lead transfer in the soil-root-plant system in a highly contaminated Andean area.

Lead (Pb) is highly toxic heavy metal that is detrimental to the food system. There are large mining and metallurgical companies in the central highlands of Peru that have been active for almost a century and contribute to air, water, and soil pollution, affecting food quality and causing damage to the environment and human health. Our study, conducted in 2018, assessed the content and transfer of lead in the soil-root-plant system in the high Andean grasslands in a geographical area near the metallurgical complex of La Oroya. Lead levels were measured in 120 samples of top soil (0–20 cm), roots, and grass shoots by flame atomic absorption spectroscopy. No significant differences were found between the soil pH, organic matter content, and lead among the samples evaluated (P > 0.05). Mean Pb concentrations decreased in the order of soil > root > shoot (P < 0.01) (212.36 ± 38.40, 154.65 ± 52.85 and 19.71 ± 2.81 mg/kg, respectively). The soil-to-root Pb bioconcentration factor, root-to-shoot translocation factor, and soil-to-shoot bioaccumulation factor values were 0.74 ± 0.26, 0.14 ± 0.06 and 0.10 ± 0.03, respectively. Lead in the soil was 3.03 times higher than the maximum limit for agricultural soil, and was 1.97 times higher than the value limit for fodder. Our findings are important and show that soils and pasture in this geographical area have high Pb levels due to metallurgical emissions that have been occurring since 1922. Such pollution negatively impacts health and the socio-economic status of the exposed populations.

Recuperación de plomo en suelo agrícola contaminado artificialmente como estrategia de remediación mediante girasol y vermicompost

Lead (Pb) contamination is an environmental problem that deteriorates the quality of agricultural soils; therefore, it is a priority to evaluate remediation strategies for its recovery. The aim of this research was to evaluate the effect of sunflower (Helianthus annuus) and vermicompost in the remediation of agricultural soils artificially contaminated with Pb. The treatments studied were: T1 (soil with Pb, vermicompost and sunflower), T2 (soil with Pb and vermicompost), T3 (soil with Pb and sunflower) and T4 (soil with Pb). The initial Pb value in the soil was 16.05 ppm, and 105 ppm Pb were added by dissolving Pb(NO3)2, reaching a concentration of 121.05 ppm as the initial level, higher than the national environmental quality standard (EQS) for agricultural soils (70 ppm Pb). All treatments reduced the Pb concentration in the soil below the EQS. T2 stood out by achieving a Pb recovery of 81.21 %. The Pb bioconcentration factor (BF) in the aerial part and roots of sunflower plants (T1 and T3) registered values of less than one, acting as an exclusive plant species. According to the Pb translocation factor (TF), sunflower in the presence of vermicompost (T1) behaved as a Pb phytostabilizing plant (TF &lt; 1), and in the absence of vermicompost (T3) it proved to be a Pb phytoextractor (TF &gt; 1).

Biochar and metal-immobilizing Serratia liquefaciens CL-1 synergistically reduced metal accumulation in wheat grains in a metal-contaminated soil

Biochar and metal-immobilizing bacteria play an important role in reducing the metal uptake of plants. However, little research has characterized the synergistic effects of biochar and metal-immobilizing bacteria on reducing metal accumulation in wheat grains and the underlying mechanisms. In this study, the effects of biochar, metal-immobilizing Serratia liquefaciens CL-1, and biochar + CL-1 on grain Cd and Pb uptake in wheat (Triticum aestivum L. Sumai-188) and the mechanisms involved under field conditions were characterized. Biochar, CL-1, and biochar + CL-1 reduced wheat grain Cd and Pb contents by 17–25%, 24–27%, and 45–55% and reduced the available Cd and Pb contents in the rhizosphere soils by 14–33%, 13–38%, and 27–57%, respectively, compared with the controls. Biochar, CL-1, and biochar + CL-1 increased soil pH values. CL-1 and biochar + CL-1 increased putrescine contents by 93% and 150% and bacterial aguA gene copy numbers by 30% and 44%, respectively, in the rhizosphere soils compared to the controls based on qPCR analysis. Furthermore, biochar + CL-1 reduced the Cd and Pb bioconcentration and translocation factors by 23–33% compared to the controls. CL-1 significantly increased the pH and reduced water-soluble Cd and Pb concentrations (18–44%) in the metal-contaminated soil solution compared to the controls. The results showed a synergistic effect of biochar and CL-1 on the reduction of Cd and Pb accumulation in wheat grains. These findings suggested that biochar plus CL-1 reduced wheat grain metal uptake by reducing metal availability and translocation from the roots to grains and increasing pH levels, putrescine production, and aguA gene abundance, and they highlight the possibility of developing an effective technique for reducing the metal uptake of wheat grains using biochar plus metal-immobilizing bacteria in metal-contaminated soils.

Distribution of Heavy Metal Lead (Pb) in Water and Plankton on Floating Net Cage Area with Different Density at Cirata Reservoir, West Java

Cirata Reservoir mostly functions as a Hydroelectric Power Plant (PLTA) and the location of fish farming with the floating cage system (KJA). Utilization of reservoirs for fish culture in Cirata Reservoir has exceeded the capacity determined by the government. This causes changes in water quality in the waters of the Cirata Reservoir and affects the concentration of heavy metal lead in the waters. The purpose of this study was to determine the distribution of heavy metal lead (Pb) that exist in the KJA with different densities in the Cirata Reservoir. This research was conducted on 3 November-8 December 2019 at Cirata Reservoir with sampling stations in Jangari, Maleber and Patokbeusi. The method used in this research is purposive sampling. The results of the physical-chemical parameter research show that the water temperature at the three stations ranges from 31.9oC-34.5oC, air temperature 27oC-32oC, transparency 53.5-76 cm, pH 6.87-7.67, CO2 8,4-16.8 mg/L, BOD 1.1-20.5 mg/L and DO 5.83-9.72 mg/L. The results of Pb measurements in water ranges from 0,001 to 0,029 mg/L. Pb measurements in plankton ranges from 0.001 to 0.039 mg/L. Pb bioconcentration factor values ​​range from 1.27 - 2.40. These results indicate that aquatic organisms in the Cirata Reservoir can accumulate metals in their bodies.

Effects and Mechanisms of Calcium Ion Addition on Lead Removal from Water by Eichhornia crassipes.

Karst water is rich in calcium ions (Ca2+) and exhibits poor metal availability and low biodegradation efficiency. This study sought to analyze the effects and mechanisms of Ca2+ on lead (Pb) removal and absorption by Eichhornia crassipes (a floating plant common in karst areas). Moreover, the morphology and functional groups of E. crassipes in water were characterized via SEM, and FTIR. The results demonstrated that the removal rate of Pb in karst water (85.31%) was higher than that in non-karst water (77.04%); however, the Pb bioconcentration amount (BCA) in E. crassipes roots in karst water (1763 mg/kg) was lower than that in non-karst water (2143 mg/kg). With increased Ca2+ concentrations (60, 80, and 100 mg/L) in karst water, the Pb removal rate increased (85.31%, 88.87%, and 92.44%), the Pb BCA decreased (1763, 1317, and 1095 mg/kg), and the Ca BCA increased (6801, 6955, and 9368 mg/kg), which was attributed to PbCO3 and PbSO4 precipitation and competitive Ca and Pb absorption. High Ca2+ concentrations increased the strength of cation exchange, alleviated the fracture degree of fibrous roots, reduced the atrophy of vascular bundles, protected the cell wall, promoted C–O combined with Pb, enhanced the strength of O‒H, SO42−, C=O, and reduced the oxidization of alkynyl acetylene bonds.

Bioconcentration, depuration and toxicity of Pb in the presence of titanium dioxide nanoparticles in zebrafish larvae

The interactions between nanoparticles (NPs) and metals in aquatic environments may modify the bioavailability and toxicity of metals to organisms. In this study, we investigated the effects of titanium dioxide NPs (n-TiO2) on the bioconcentration, depuration, and neurotoxic effects of lead (Pb) in zebrafish larvae. Transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy showed that Pb2+ was adsorbed by n-TiO2 to form NP–Pb complexes in suspension, and these complexes were observed in larval tissues. The bioconcentration of Pb in larvae along with the depuration rates of Pb were higher in the presence of n-TiO2 compared to when n-TiO2 was absent. Exposure to Pb alone induced the expression of the biomarker metallothionein, downregulated neurodevelopment-related genes, and reduced swimming activity of larvae. However, the addition of n-TiO2 to the exposure solution alleviated these effects. The results suggest that n-TiO2 can act as a carrier of Pb to increase its bioconcentration; however, the formation of NP–Pb complexes likely reduces the amount of free Pb2+, thereby reducing toxicity to larvae.

Impact of co-exposure to titanium dioxide nanoparticles and Pb on zebrafish embryos

Complex interactions have been established between nanoparticles (NPs) and heavy metals in real environments. Herein we used zebrafish embryos to investigate the influence of titanium dioxide NPs (n-TiO2) on the uptake, bioconcentration, and depuration, and toxicity of Pb. The formation of n-TiO2–Pb complexes was confirmed in an exposure suspension. An increase in Pb bioconcentration was observed in zebrafish embryos upon co-exposure to n-TiO2 and Pb; moreover, n-TiO2–Pb complexes could be found in the embryos, indicating the bioavailability of NPs. However, there was no difference in the depuration rates of Pb in the presence of n-TiO2. Metallothionein (MT) content was significantly increased upon exposure to Pb alone, and the content significantly increased even further upon co-exposure. A downregulation in the expression levels of the neurodevelopment-related genes gfap, syn2α, and elavl3 was observed in the embryos, and we also noted a reduction in the swimming speed of and the total distance traveled by the larvae. To summarize, our results indicate that n-TiO2 can act as an effective carrier of Pb to enhance its uptake, bioavailability, and toxicity in zebrafish embryos.

The Environmentally Sound Aquaculture Strategies Based on Bioaccumulation of Heavy Metal of Lead (Pb) on Seaweed of Gracilaria verrucosa on Aquaculture Areas of MuararejaVillage, Tegal City

Community activities such as industry, trade, animal husbandry and agriculture and ssettlements resulting in heavy metals of lead (Pb) can be accumulated in water, sediment and seaweed Gracillaria verrucosa. It can contaminate ponds and affect aquaculture activities in Tegal. Seaweed Gracilaria verrucosa is afisheries commodity that has economical value and cultivated in the area of aquaculture MuararejaTegal. It can serve as fitoremedian that will help reduce the impact of heavy metal pollution due to its ability to accumulate pollutants. The objective of this study was to analyze bioaccumulation of heavy metals of lead (Pb) and its relationship with water quality management in order to develop seaweed cultivation of Gracillaria verrucosa in ponds in the area of aquaculture MuararejaTegal. The method used in this study is a survey, analysis of heavy metals of lead (Pb) in pond water, sediment and seaweed using Atomic Absorption Spectrophotometer (AAS) and the data were analyzed by descriptive quantitative. Bioconcentration of lead (Pb) during the dry season in pond water, sediment and seaweed Gracillaria verrucosa was measured from 0.003 to 0.025 ppm,5.543 to 23.699 ppm and 0.209 to 0.326 ppm respectively. While in the rainy season bioconcentration of lead (Pb) are from 0.003 to 0.015 ppm, sediment from 6.377 to 9.858 ppm and 0.209 to 0.326 ppm respectively. Bioconcentration of Pb in dry season was higher than in the rainy season and the biggest bioconcentration was found in the sediment pond waters. Pb bioaccumulation low and still below the quality standards of the Ministry of Environment decision 51 of 2004 so that the product is safe for consumption.

TINGKAT BIOKONSENTRASI LOGAM BERAT DAN GAMBARAN HISTOPATOLOGI IKAN MUJAIR (Oreochromis Mossambicus) YANG HIDUP DI PERAIRAN TUKAD BADUNG KOTA DENPASAR

Tukad Badung River is one of the potential contamination of heavy metal sare very highin the city of Denpasar. Tilapia (Oreochromis mossambicus) isa commonspecies of fish found in the river and became the object of fishing by the public. The fish is usually consume das a food ingredient forever yangler. Fish can be used as bio-indicators of chemical contamination in the aquatic environment. Determination of heavy metal bioconcentration and analysis of liver histopathology gills organs and muscles is performed to determine the content of heavy metals Pb, Cd, and Cr+6, and the influence of heavy metal exposure to changes in organ histopathology Tilapia that live in Tukad Badung. In this observational study examined the levels of heavy metal contamination include Pb, Cd and Cr+6 in Tilapia meat with AAS method (Atomic Absorption Spectrofotometric), and observe the histopathological changes in organ preparations gills, liver, and muscle were stained with HE staining (hematoxylin eosin). Low Pb content of the fish that live in Tukad Badung 0.8385 mg/kg and high of 20.2600 mg/kg. The content of heavy metals Pb is above the quality standards specified in ISO 7378 : 2009 in the amount of 0.3 mg / kg. The content of Cr+6 low of 1.1402 mg / kg and the highest Cr+6 is 6.2214 mg / kg. The content of Cr+6 is above the quality standards established in the FAO Fish Circular 764 is equal to 1.0 mg / kg. In fish with Pb bioconcentration of 0.8385 mg / kg and Cr+6 of 1.1402 mg / kg was found that histopathological changes gill hyperplasia and fusion, the liver was found degeneration, necrosis, and fibrosis, and in muscle atrophy found. Histopathologicalchangessuch asedema and necrosis ofthe liveris foundin fishwith Pb bioconcentration of 4.5225mg/kg and Cr+6 amounted to2.5163mg/kg. Bio concentration of heavy metal contamination of lead (Pb) and hexavalent chromium (Cr+6) on Tilapia ( Oreochromis mossambicus ) who lives in Tukad Badung river waters exceed the applicable standard. Histopathological changes occur in organs gills, liver, and muscle as a result of exposure to heavy metals lead and hexavalent chromium. Advised the people not to eat Tilapia that live in Tukad Badung