Bioaccumulation Factor Values Research Articles

Heavy metals and potential health risk assessment of Lactuca sativa and Daucus carrota from soil treated with organic manures and chemical fertilizer

The large-scale production of food crops with heavy application of chemical fertilizers in the effort to meet the astronomical increase in food demands may be counterproductive to the goal of food security. This study investigated the effect of different soil treatments on the levels of heavy metals (Cr, Cu, Fe, Ni, Pb, and Zn) in two types of vegetables Lactuca sativa (lettuce) and Daucus carrota (carrot). The potential carcinogenic and non-carcinogenic health risks from their consumption were also evaluated. Planting experiment was set up in a randomized block design, with different soil treatments of soil + cow dung (CD), soil + sewage sludge (SS), soil + chemical fertilizer (nitrogen-phosphorus-potassium (NPK)), and untreated soil (UNTRD). The vegetables were harvested at maturity, washed with distilled water, and subjected to an acid digestion process before the levels of heavy metals were measured by inductively coupled plasma spectrometry (ICP-MS). The mean concentrations of the metals in the vegetables across all treatments were below the maximum permissible limits. The pattern of heavy metal accumulation by the vegetables suggested that the lettuce from SS treatment accumulated higher concentrations of heavy metals like Cr (0.20 mg/kg), Cu (3.91 mg/kg), Ni (0.33 mg/kg), and Zn (20.44 mg/kg) than carrot, with highest concentrations of Fe (90.89 mg/kg) and Pb (0.16 mg/kg) recorded in lettuce from NPK treatment. The bioaccumulation factor (BAF) showed that lettuce, a leafy vegetable, has bioaccumulated more heavy metals than carrot, a root vegetable. The BAF was generally below the threshold value of 1 in both vegetables, except in lettuce from NPK and CD treatments and carrot from NPK treatments, with BAF values of 1.6, 1.69, and 1.39, respectively. The cancer risk assessment factors were well below the unacceptable maximum range of 10−4 suggesting that consuming these vegetables might not expose an individual to potential risk of cancer development. The hazard quotient estimations were below the threshold values of 1 for all heavy metals; however, the hazard index (HI) values of 1.27 and 1.58 for lettuce from NPK and SS treatments indicate a potential non-carcinogenic health risk to consumers from intake of all the heavy metals.

Screening of low-Cd-accumulating and Cd-remediating oilseed rape varieties using a newly indicator system for risk management of Cd-contaminated agricultural land

Although oilseed rape is frequently used as an alternative planting crop in the phytoremediation of cadmium (Cd)-contaminated agricultural land, methods for screening excellent oilseed rape varieties in this regard are inadequate. Herein, we developed a screening method that incorporates Cd accumulation, distribution, and removal, economic output, adaptability to Cd-contaminated agricultural land, and trace element variation. A Cd-adaptability index (Cd-AI) based on 10 agronomic traits was used to measure the adaptability of varieties to Cd-contaminated agricultural land. Moreover, to simplify the evaluation of adaptability, yield, biomass, and pod number with high weightings were selected to construct a discriminant function for Cd-contaminated agricultural land adaptability (correctly classified 94.20%). In a 2 year field trial, we evaluated 225 oilseed rape varieties, among which we identified two promising low-Cd-accumulating and two Cd-remediating varieties. For the low-Cd-accumulating varieties (HuYou17 and DeXingYou558), we obtained grain bioaccumulation factor (BAF) values of 0.07 and 0.08, BAFsoil-stalk values of <1, and economic outputs of RMB 25,054 and 32,292 yuan hm−2, respectively. Similarly, the Cd-remediating varieties (ZaoZa8 and YuYou61) were characterized by BAFsoil-stalk values of 4.65 and 3.61, BAFsoil-grain values of 0.16 and 0.16, Cd removals of 69.02 and 58.25 g hm−2, and economic outputs of RMB 31,189 and 24,962 yuan hm−2, respectively. Compared with the control variety, we detected lower uptakes of multiple trace elements (3–43%) in the low-Cd-accumulating varieties, whereas the Cd-remediating varieties were characterized by 15.40% and 8.30% increases in the accumulation of magnesium and zinc, respectively. Our findings augment the evaluation indices used for evaluating oilseed rape varieties and provide valuable insights from the perspectives of varietal screening and promotional application. The effective varieties identified have application potential for safe production and the remediation of agricultural land without interrupting annual agricultural production, and provide an economically sustainable approach for the utilization of Cd-contaminated agricultural land.

Heavy Metal Accumulation in Three Varieties of Mustard Grown under Five Soil Management Practices

Heavy metal pollution represents a global health issue. Different methods and technologies are adopted to mitigate the problem of heavy metal pollution. Phytoremediation has been gaining attention as an environmentally friendly method to remediate this problem. The purpose of this research is to explore the effectiveness of phytoremediation in agricultural settings to assess the effect of five soil management practices (chicken manure, sewage sludge, leaf compost, cow manure, and vermicompost) on Cd, Cu, Mo, Ni, Pb, and Zn accumulation in the mustard (leaves and pods) of three mustard Brassica juncea varieties (black mustard, yellow mustard, and mighty mustard). The accumulation in mustard was quantified using the Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES). The results showed that the bioaccumulation factor (BAF) of the three mustard varieties exceeded one (BAF &gt; 1) for Cd and Mo. It indicates that mustard is a good accumulator of Cd and Mo, whereas BAF values for Cu, Pb, Ni, and Zn were less than one (BAF &lt; 1). The accumulated Cu, Mo, Ni, and Zn levels were below the allowable limit, whereas the Cd and Pb levels were beyond the limit. This result indicates that the investigated mustard varieties can be grown on heavy metal polluted sites for Cd and Mo phytoremediation purposes, but care is needed with regard to Cd and Mo toxicity.

Sediment-seawater partitioning, bioaccumulation, and biomagnification of perfluorobutane sulfonamide in marine environment

Environmental occurrence of perfluorobutane sulfonamide (PFBSA) has only been recently discovered. The current knowledge regarding the occurrence and environmental behaviors of PFBSA in the marine environment is still relatively limited. In this study, PFBSA and other 37 poly- and perfluoroalkyl substances were analyzed in seawater (n = 43), sediment (n = 43), and marine fish (n = 176) samples collected from East China Sea and Antarctic Ocean. PFBSA was detected in > 90% of seawater from East China Sea and Antarctic Ocean, with the concentrations of 1.0 − 19 ng/L and < LOD−228 pg/L, respectively. The field-based mean log-transformed sediment-seawater partitioning coefficients of PFBSA were 1.6 ± 0.19 L/kg dw and 1.1 ± 0.19 L/kg dw in East China Sea and Antarctic Ocean, respectively, which are lower than that of perfluorooctanoate and perfluorooctane sulfonate. This indicates its long-range transport potential in global oceans with ocean currents. The mean log-transformed bioaccumulation factor values of PFBSA determined in the multiple species of whole-body marine fishes from East China Sea and Antarctic Ocean were 2.3 L/kg ww and 2.4 L/kg ww, respectively, which are comparable to that of perfluoroheptanoate (2.3 L/kg ww) in marine fishes from East China Sea. We did not observe an obvious biomagnification or biodilution of PFBSA along the marine food chain in East China Sea or Antarctic Ocean. This study provides the first data on the environmental behaviors of PFBSA in the marine environment.

Evaluation of the tolerance and accumulation potential of selected sunflower hybrids grown in soil contaminated with cadmium

Common sunflower (Helianthus annuus L.) belongs to the group of crops with high biomass and high capacity for the accumulation of various metals. Previous studies have suggested that remedial potential is strongly determined by genotype. In our study, we evaluated the tolerance of six sunflower hybrids (P64HE118, P64LE136, P62LE122, P64HE133, P64HE144 and P63LP25) to cadmium ions (Cd 100 mg kg−1 soil), and we also evaluated their remediation potential. All tested hybrids showed high tolerance to Cd, no significant changes were noted with regard to growth, content of photosynthetic pigments, leaf area, water content, proline content, or accumulation of superoxide dismutase (SOD) isoforms. We noted an increased rate of membrane lipid peroxidation for P64HE118, P64LE136 and P64HE144 hybrids. The increased content of glutathione in the leaves of P64HE118 and P64LE136 hybrids indicates this molecule's involvement in the Cd detoxification process. All hybrids accumulated Cd preferentially in the roots. The most Cd was accumulated in the roots and shoots of hybrid P64HE118. Values of bioaccumulation factor and translocation factor were hybrid-dependent, being generally higher for standard/control soil (Cd 1.2 mg kg−1 soil). Better phytoremediation potential of these hybrids can hence be expected at lower Cd doses in the soil. The high tolerance of tested hybrids to a higher dose and the non-negligible accumulation of Cd in roots also supports using these hybrids in soil phytostabilisation.

Global environmental and toxicological impacts of polybrominated diphenyl ethers versus organophosphate esters: A comparative analysis and regrettable substitution dilemma

The prevalence of organophosphate esters (OPEs) in the global environment is increasing, which aligns with the decline in the usage of polybrominated diphenyl ethers (PBDEs). PBDEs, a category of flame retardants, were banned and classified as persistent organic pollutants (POPs) through the Stockholm Convention due to their toxic and persistent properties. Despite a lack of comprehensive understanding of their ecological and health consequences, OPEs were adopted as replacements for PBDEs. This research aims to offer a comparative assessment of PBDEs and OPEs in various domains, specifically focusing on their persistence, bioaccumulation, and toxicity (PBT) properties. This study explored physicochemical properties (such as molecular weight, octanol-water partition coefficient, octanol-air partition coefficient, Henry's law constant, and vapor pressures), environmental behaviors, global concentrations in environmental matrices (air, water, and soil), toxicities, bioaccumulation, and trophic transfer mechanisms of both groups of compounds. Based on the comparison and analysis of environmental and toxicological data, we evaluate whether OPEs represent another instance of regrettable substitution and global contamination as much as PBDEs. Our findings indicate that the physical and chemical characteristics, environmental behaviors, and global concentrations of PBDEs and OPEs, are similar and overlap in many instances. Notably, OPE concentrations have even surged by orders of several magnitude compared to PBDEs in certain pristine regions like the Arctic and Antarctic, implying long-range transport. In many instances, air and water concentrations of OPEs have been increased than PBDEs. While the bioaccumulation factors (BAFs) of PBDEs (ranging from 4.8 to 7.5) are slightly elevated compared to OPEs (−0.5 to 5.36) in aquatic environments, both groups of compounds exhibit BAF values beyond the threshold of 5000 L/kg (log10 BAF > 3.7). Similarly, the trophic magnification factors (TMFs) for PBDEs (ranging from 0.39 to 4.44) slightly surpass those for OPEs (ranging from 1.06 to 3.5) in all cases. Metabolic biotransformation rates (LogKM) and hydrophobicity are potentially major factors deciding their trophic magnification potential. However, many compounds of PBDEs and OPEs show TMF values higher than 1, indicating biomagnification potential. Collectively, all data suggest that PBDEs and OPEs have the potential to bioaccumulate and transfer through the food chain. OPEs and PBDEs present a myriad of toxicity endpoints, with notable overlaps encompassing reproductive issues, oxidative stress, developmental defects, liver dysfunction, DNA damage, neurological toxicity, reproductive anomalies, carcinogenic effects, and behavior changes. Based on our investigation and comparative analysis, we conclude that substituting PBDEs with OPEs is regrettable based on PBT properties, underscoring the urgency for policy reforms and effective management strategies. Addressing this predicament before an exacerbation of global contamination is imperative.

Study of controlling the content heavy metals Pb, Cu, Cd, and Cr in land using hyperaccumulator plants

This study aimed to determine the types of hyperaccumulator plants that can absorb the heavy metal content of Pb, Cu, Cd, Cr based on the values of bioaccumulation factors (BAF) and translocation factors (TF). Results of the analysis showed that BAF value of the hanjuang plant (Cordyline fruicosa), for heavy metal Pb was 0.369; Cu 0.442; Cd 0.055; Cr 0.078 and TF value for heavy metal Pb 1.572; Cu 0.964; Cd 0.108; Cr 1.358. Croton plant (Codiaeum variegatum), had a BAF value of Pb 0.021; Cu 0.060; Cd 0.000; Cr 0.003 and TF value of Pb 3.638; Cu 0.000; Cd 0.000; Cr 1.399. Sansevieria plant (Sansevieria trifasciata) had a BAF value of Pb 0.090; Cu 0.036; Cd 0.015; Cr 0.002 and TF value of Pb 0.410; Cu 0.334; Cd 0.222; Cr 0.726. Sunflower plant (Helianthus annuus) had a BAF value of Pb 0.022; Cu 0.094; Cd 0.308; Cr 0.001 and TF value of Pb 1.930; Cu 0.399; Cd 1.383; Cr 1.361. Based on a comparison of BAF values, hanjuang plant was the best hyperaccumulator plant capable of accumulating Pb, Cu, Cr with a phytoextraction mechanism and accumulating Cd with a phytostabilization mechanism. At the same time, sunflower a hyperaccumulator plant with the best translocation factor where the roots of sunflower plants absorbed Pb, Cu, Cd, Cr, which were then translocated to the stems and leaves optimally through a phytoextraction mechanism.

Determination of Some Selected Heavy Metals in Wheat and Pepper Samples Collected from Gaziantep (Türkiye)

It is very important for the environment and human health to determine the level of accumulation of pollutants in the soil and in the edible parts of plants, especially as a result of the intensive use of chemicals in agricultural activities. For this reason, this study was carried out to determine the heavy metal levels (Cd, Pb, Cr, Ni, Cu, Zn, Mn, Fe and Co) of wheat grain, red pepper and samples of soil from Nurdağı and Islahiye districts where intensive agricultural activities are carried out in Gaziantep (Türkiye). Sampling of agricultural products and their cultivated soils was made at harvest time. The Cd and Pb levels of red pepper and the Cd, Pb and Cr levels of the soil collected from Nurdağı were generally higher than those of FAO/WHO limits. Lead content of wheat grain collected from Nurdağı and Cd and Pb contents of soil samples were also higher than the permissible limits. On the other hand, Cd levels of red pepper and soil samples from Islahiye were higher than those of the FAO/WHO limits. In addition, it was determined that Pb and Cr levels of wheat and Cd and Pb levels of soil samples from Islahiye were generally above permissible limits. On the other hand, in the samples collected from Nurdağı, the highest bioaccumulation factor (BAF) values were calculated for Cd, Cu and Zn in red pepper and for Cu, Zn and Pb in wheat grains. Considering the samples collected from Islahiye, the highest BAF values were calculated in Zn, Cr and Pb for red pepper, and Zn, Cd and Cu for wheat grains. As a result, the concentrations of some heavy metals such as Cd, Pb and Cr were found to be higher than the recommended limits. It was concluded that the reason for this is the intense application of agricultural activities, especially pesticides and inorganic fertilizers, in both districts.

Phytoremediation efficacy of Nerium oleander L. for removal of Cd, Ni, and Pb- contaminated soil

A pot experiment was conducted to assess the effectiveness of Nerium oleander L. in phytoremediation of cadmium (Cd), nickel (Ni), and lead (Pb)- contaminated soil. This evaluation included the application of ethylene diamine tetra-acetic acid (EDTA) and a nutrient solution containing NPK. The results revealed that the inclusion of EDTA and NPK, in combination with varying metal concentrations, significantly increased the dry weight of the plants. The results demonstrated that oleander, when aided by EDTA and NPK, exhibited a high capacity to efficiently absorb and accumulate Pb without any amendments. The addition of EDTA increased Pb concentrations in both aerial parts and roots (84.9 mg kg-1 and 80.2 mg kg-1, respectively). For Nickel, in the presence of NPK, the concentration in roots was 80,2 mg kg-1. Cd accumulation was highest in the treatment with 100 mg kg-1 EDTA, reaching 72.9 mg kg-1 in the aerial parts. Particularly, NPK reduced Ni levels in aerial parts, while EDTA enhanced root metal uptake. The Translocation Factor (TF) was greater than 1 for Cd and Ni treatments, indicating oleander's remarkable ability to absorb and accumulate these heavy elements. The treatment involving Pb50+EDTA displayed the highest Bioaccumulation Factor (BAF) value at 1.7. Furthermore, for Pb50, Ni50 and Cd50, the NPK treatment exhibited the highest Bioconcentration Factor (BCF) values, ranging from 0.3 to 1.69. Nerium oleander L. exhibits promise for both Ni phytoextraction and Cd and Pb phytostabilization, suggesting its potential as an effective phytoremediation agent. Future research should focus on optimizing metal uptake conditions and investigating long-term plant health and soil impacts to refine sustainable strategies for mitigating metal pollution in contaminated environments.

Bioaccumulation of zinc in rice (oryza sativa l.) from River Swat, Panjkora, And Kabul Pakistan

Ecosystem contamination with heavy metals lead to the bioaccumulation of these elements in crops. Rice, a significant component of the human diet, can bioaccumulate heavy metals and is of public health concerns. Therefore, the current research aimed to investigate the bioaccumulation of the heavy metal zinc in several rice varieties from three rivers in Pakistan's Malakand Division. The Highest Zn concentration of 91.58± 6.25 mg kg−1 dry weight was observed in rice roots of China Basmati variety grown across River Swat, while the highest Zn concentration of 60.06 ± 4.41 mg kg−1 dry weight was observed in the stem of Mota Chawal on River Kabul. In a site-wise comparison of both River Swat and Kabul, the Zn concentrations in the stem of Sara Sela rice on River Panjkora were 55.5±4.37, showing significant differences among different sites on the rivers. Similarly, comparing metal concentrations in different rice varieties generally did not show significant differences between the varieties. Zn concentrations in rice were higher in the Swat River than in the rest in all cases. Bioaccumulation factor (BAF) values for Zn were in the order of soil &gt; roots &gt; stem &gt; leaves &gt; grains for River Swat and Kabul. In contrast, for River Panjkora Zn concentration, the order was soil &gt; stem &gt; root &gt; grains&gt; leaves, respectively. Zn absorption by rice in the form of ions or particles generally affects plant phenotypic, physiological, and molecular development; hence, it must be considered in present varieties for the future.

Accumulation of livestock manure–derived heavy metals in the Hexi Corridor oasis agricultural alkaline soil and bioavailability to Chinese cabbage (Brassica pekinensis L.) after 4-year continuous application

Hexi Corridor is one of the most important base of vegetable producing areas in China. Livestock manure (LM) applied to agricultural field could lead to soil heavy metal (HM) pollution. Previous studies have focused on HM pollution following LM application in acidic polluted soils; however, fewer studies have been conducted in alkaline unpolluted soils. A 4–year field vegetable production experiment was conducted using pig manure (PM) and chicken manure (CM) at five application rates (0, 15, 30, 45, and 60 t ha−1) to elucidate potential risks of HMs in an alkaline unpolluted soil in the Hexi Corridor oasis agricultural area and HM uptake by Chinese cabbage. The results showed that LM application caused a significant build–up of Cu, Zn, Pb, Cd, and Ni content in topsoil by 30.6–99.7%, 11.4–51.7%, 1.4–31.3%, 5.6–44.9%, 14%–40.8%, respectively. The Cd, Cu, Zn could potentially exceed the soil threshold in next 8–65 years after 15–60 t ha−1 LM application. Under LM treatment, the soil DTPA–extractable Cu, Zn, Fe, the acid–extractable fraction of Cu, Zn, Fe, Cd, Ni, and the Oxidable fraction of Cu, Zn, Fe, Mn, Cd, Ni significantly increased, but the DTPA–extractable Pb, Cd, the acid–extractable fraction of Pb, and the reducible fraction of Cd significantly decreased. Cu and Zn could migrate to the deeper soil and relatively increase in DTPA–extracted Cu, Zn were found in 20–40 cm soil depth after LM application. The pH and SOM could influence the bioavailability of HMs in soil. The bioaccumulation factor and transfer factor (TF) values were <1 except Mn (TF > 1). HMs in leaf did not approach the threshold for HM toxicity due to the “dilution effect”. Recommend the type of manure was the PM and the annual PM application rate was 30 t ha−1 to ensure a 20–year period of clean production in alkaline unpolluted Fluvo–aqiuc vegetable soils.

Trophic transfer and their impact of microplastics on estuarine food chain model

Microplastic contamination in marine ecosystems, and its negative effects through trophic transfer among marine organisms, remains a growing concern. Our study investigates the trophic transfer and individual impacts of polystyrene microplastics (MPs) in an estuarine food chain model, comprising Artemia salina as primary organism, Litopenaeus vanamei as secondary organism, and Oreochromis niloticus as tertiary organism. A. salina were exposed to 1 µm polystyrene microplastics (106 particles/ml), further it was fed to L.vannamei, which, in turn, were fed to O.niloticus. MPs transfer was studied over 24 and 48 h. Fluorescence microscopy confirmed MPs presence in the gut and fecal matter of all the test organisms. Histopathology revealed MPs in the gut epithelium, but did not translocate to other tissues of the test species. MPs exposed A.salina had a bioconcentration factor of 0.0029 ± 0.0008 (24 h) and 0.0000941 ± 0.0000721 (48 h). Whereas, the bioaccumulation factor values for L. vanamei were 0.00012143 ± 0.000009 (24 h) and 0.0025899 ± 0.0024101 (48 h), and for O.niloticus were 0.154992 ± 0.007695 (24 h) and 0.00972577 ± 0.00589923 (48 h). Despite low MPs transfer among trophic levels, the induced stress was evident through biochemical responses in all the test species. This implies the potential risk of MPs ultimately reaching humans via the food chain.

Competitive adsorption and bioaccumulation of sulfamethoxazole and roxithromycin by sediment and zebrafish (Danio rerio) during individual and combined exposure in water

Antibiotics are extensively used for health protection and food production, causing antibiotic pollution in the aquatic environment. This study aims to determine the bioavailability and bioaccumulation of typical antibiotics sulfamethoxazole (SMX) and roxithromycin (RTM) in zebrafish under environmentally realistic conditions. Four different microcosms, i.e. water, water-sediment, water-zebrafish, and water-sediment-zebrafish were constructed, with three replicates in parallel. The concentrations of SMX and RTM in water, sediment and zebrafish were extracted and analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) to assess their kinetic behavior and bioavailability. In the water-sediment system, the dissolved concentration of both SMX and RTM decreased with time following the first-order kinetic while their adsorption by sediment increased with time. In the water-zebrafish system, SMX and RTM bioaccumulation was increasing with time following the pseudo second-order kinetics. RTM bioaccumulation in zebrafish (up to 16.4 ng/g) was an order of magnitude higher than SMX (up to 5.2 ng/g), likely due to RTM being more hydrophobic than SMX. In addition, the bioaccumulation factor (BAF) value of SMX in zebrafish was greater than its sediment partition coefficient, while the opposite trend was observed for RTM, demonstrating the importance of antibiotics properties in affecting their bioavailability. Furthermore, increasing dissolved organic carbon concentration in water reduced SMX bioaccumulation, but increased RTM bioaccumulation at the same time. The findings are important in future studies of environmental fate and bioavailability of toxic chemicals with different pollution sources and physicochemical properties.

Assessment of herbaceous ornamental plant species as potential remediation agents for cadmium contaminated environments

Industrial development has led to the pollution of lands with Cadmium (Cd), resulting in the contamination of edible crops and posing significant health risks to humans and animals. To address this issue, the selection of non-edible ornamental plants has been considered. In this study, a lab-scale experiment was conducted using five different ornamental plant species: Tabermaeontana divaricata L., Syngonium podophyllum Schott, Asparagus setaceus (Kunth) Jessop, Catharanthus roseus (L.) G. Don. and Portulaca grandiflora Hook. These plant species were treated 100 mL of 5 mg L−1 CdSO4 solution, continuing for 30 days in hydroponic medium with replenishment with same solution on every 3rd day. The main objective was to identify ornamental plant species with high tolerance and remarkable Cd translocation and accumulation power. The plants were evaluated based on their Tolerance Index (TI), Translocation factor (TF) and Bioaccumulation Factor (BAF) toward Cd in the hydroponic medium. P. grandiflora exhibited high tolerance to Cd with 95 % TI and S. podophyllum (TI – 85 %) and T. divaricata (TI – 62 %) showed limited tolerance while C. roseus and A. setaceus were found to be more sensitive. Moreover, Cd presence was also found to induce a hormetic response in P. grandiflora, T. divaricata, and S. podophyllum. Based on their TF and BAF values, P. grandiflora (TF-5.45; BAF-0.86) and S. podophyllum (TF-4.49; BAF-0.85) were identified as potential candidates for phytoextraction, while T. divaricata (TF-0.007; BAF-4.34) showed potential as a phytostabilizer of Cd. These findings propose for the utilization of these ornamental plants for the remediation of the Cd-contaminated soil and water, with the harvested biomass potentially serving as bio-ore for recovery of Cd.

Occurrence and bioaccumulation of parabens and their metabolites in the biota from a subtropical freshwater river ecosystem: Implications for human exposure

Widespread occurrence of parabens in the environment has been documented, whereas little information is available about the occurrence and bioaccumulation of parabens in the aquatic biota. In this study, plants (n = 14), plankton (n = 20), and fish muscle (n = 89) samples were collected from Dongjiang River Basin and analyzed for nine parabens and two of their metabolites using ultra-high performance liquid chromatogram-tandem mass spectrometry. All the samples contained notable concentrations of parabens and the metabolites, and the total concentrations of parabens (Σp-PBs; sum of nine parent compounds) ranged from 0.40 to 776 ng/g dry wt. MeP, EtP, and PrP were the predominant parent compounds in both plankton and fish, while in plants, MeP, BzP and EtP were the top three abundant chemicals. As the predominant metabolite, 4-HB was detected in 99% aquatic biota samples analyzed with the highest concentration (24800 ng/g, dry wt) detected in an alga. Significantly positively correlations among the concentrations of MeP, BzP, EtP and 4-HB in the fish muscle were found. Based on dry weight, bioaccumulation potentials of these chemical substances were estimated with bioaccumulation factor (BAF) values greater than 2000 L/kg, suggestive of bioaccumulative in aquatic biota. Based on the concentrations measured, the estimated daily intakes (EDIs) of parabens through fish consumption were estimated with the mean EDIs being 4.20, 2.41, and 1.93 ng/kg bw/day for toddlers, children, and adults in urban, respectively. This study provides baseline information about the occurrence and fate of parabens in the aquatic environment.

Stereoselective bioaccumulation and dissipation of four stereoisomers of cyproconazole in earthworm-soil microcosm

Cyproconazole is a representative and widely used triazole fungicide with four stereoisomers, which will bring some risks to non-target organisms. A fast analytical method on supercritical fluid chromatography-tandem mass spectrometry was established in 4 min, and the environmental hazards of chiral cyproconazole were studied in earthworm-soil microcosm, including stereoselective bioaccumulation and dissipation. In the process of bioaccumulation, the concentrations of cyproconazole stereoisomers in earthworms showed a trend of increasing first and then reaching a stable state at 6 mg/kg treatment, which was different from those at 0.6 mg/kg treatment (decease-increase-equilibrium). The concentration order was (2S,3R)- > (2S,3S)- > (2R,3R)- > (2R,3S)-cyproconazole and (2S,3S)- ≈ (2S,3R)- > (2R,3R)- > (2R,3S)-cyproconazole at 6 and 0.6 mg/kg treatments, respectively. The bioaccumulation factor (BAF) values were in the range of 0.018–0.55, showing weakly relative accumulation capacity. The dissipation of cyproconazole stereoisomers in artificial soil accorded with the first-order kinetics equation, and the half-lives were 20.1–23.6 and 7.66–8.28 days at 6 and 0.6 mg/kg treatments, respectively, without stereoselectivity and diastereoselectivity. In earthworms, the dissipation half-lives were 5.81–6.01 days with the preferential dissipation of (2R,3R)-cyproconazole. The study would help with the rational uses and risk assessments of cyproconazole.

Seasonal variations of some heavy metals in common reed (Phragmites australis (Cav.) Trin. Ex. Steudel) and narrow-leaved cattail (Typha angustifolia L.) in Eğirdir Lake (Turkey) and the possibility of using for phytoremediation of these macrophytes.

This study which was carried out between July 2019 and April 2020 aimed to determine the seasonal changes of heavy metals (Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, and Zn) in plant organs of Phragmites australis and Typha angustifolia grown in Eğirdir Lake and to research the usability of the these plants for phytoremediation with the calculation of bioaccumulation factor (BF). Plant samples were brought to the laboratory, and then washed, cleaned with distilled water, dried in an oven at 70°C and acidified with 10ml HNO3. The samples were heated at 120°C on a hot plate until completely mineralized. After mineralization, heavy metal concentrations were determined by using ICP-AES (Vista model). Only Mo was the highest in leaf, while other metals were highest in root in P. australis. In T. angustifolia, Mn and Mo were highest in the leaf, the accumulation of other metals was observed to be higher in the plant's roots than the other organs. It was discovered that the metal concentrations in root, in stem, and in leaf for both macrophytes generally increased in summer and decreased in root in autumn and winter and in stem and in leaf in spring for P. australis and in all organs in spring for T. angustifolia. Bioaccumulation factor (BF) values were calculated to determine the phytoremediation potential of P. australis and T. angustifolia. Both macrophytes are not excluder for all metals. Plants revealed potential for phytoremediation for the removal of heavy metals especially Mo and Zn. As a result of our study, it was determined that both macrophytes had accumulation abilities especially for Mo and Zn. It should be taken into consideration that these macrophytes can be used for improving the current situation of Eğirdir Lake due to their advantages such as being economical and not causing any harm to the environment.

Bioaccumulation of novel brominated flame retardants in crucian carp (Carassius auratus): Implications for electronic waste recycling area monitoring

Bioaccumulation factor (BAF) of pollutants is an important parameter for evaluating their bioaccumulation potential and an important indicator for evaluating their environmental risks. However, little study exits on the BAF of novel brominated flame retardants (NBFRs). The present study determined 17 NBFRs in 24 water samples in dissolved phase and 93 crucian carp samples collected from an electronic waste recycling site in northern China, in order to examine their contamination, distribution and bioaccumulation. The results showed that the targeted NBFRs were widely detectable in the dissolved phase and crucian carps. In dissolved phase, allyl 2,4,6-tribromophenyl ether (ATE) had the highest detectable rate (100%) and concentration (mean: 1.3 ± 0.62 ng/L), but in crucian carp, hexachlorocyclopentenyl-dibromocyclooctane (HCDBCO) was the one with the highest detectable rate (89%) and concentration (mean: 16 ± 9.2 ng/g wet weight (ww)) among all 17 NBFRs. The discharge and water solubility of NBFRs determined their concentration in the dissolved phase, while the concentration of NBFRs in crucian carp was the results of their discharge and food exposure. The estimated BAFs exceeded 5000 L/kg for petabromoethylbenzene (PBEB), pentabromotoluene (PBT), HCDBCO, pentabromobenzyl acrylate (PBBA), 1,2,3,4,5-pentabromobenzene (PBBZ), 2,3-dibromopropyl-2,4,6-tribromophenyl ether (DPTE), hexabromobenzene (HBBZ), and α-1,2,5,6-tetrabromocyclooctane (α-TBCO), suggesting that these compounds were above the hazard standard of bioaccumulation. Although the BAFs of 2,3,5,6-tetrabromo-p-xylene (p-TBX), 1,2-bis(2,4,6-tribromophenoxy)-ethane (BTBPE), α-/β-tetrabromoethylcyclohexane (α-/β-TBECH) and ATE were less than 5000, the potential of bioaccumulation cannot be ignored. The log BAF of tested NBFRs showed a pattern of first increasing and then decreasing with the increase of log KOW, the water solubility of NBFRs, the exposure to fish, the uptake and depuration of fish were the key factor to this pattern. To our knowledge, the BAF values of the most of NBFRs calculated in this study were not reported in the published work previously.

A comprehensive health risk assessment associated with bioaccumulation of heavy metals and nutrients in selected macrophytes of Loktak Lake, Manipur, India.

The Loktak Lake, a Ramsar site in Northeast India, is known for its rich biodiversity that includes a variety of macrophyte species, most of which have not been studied for their phytoremediation capacities and potential toxicity via consumption of the edible species. Therefore, a comprehensive assessment was conducted to evaluate the accumulation of selected heavy metals and nutrients in 10 dominant macrophyte species growing in Loktak Lake and to assess the potential health risks associated with consumption of the edible plants. The concentrations of nutrients such as total phosphorus (TP), total nitrogen (TN), potassium (K), calcium (Ca), magnesium (Mg), and heavy metals such as copper (Cu), manganese (Mn), zinc (Zn), and iron (Fe) were found to be in the order of plant > sediment > water. The bioaccumulation factors (BAFs) revealed high efficiency of most plants to accumulate heavy metals and nutrients in their tissues from the lake water and sediments, indicating their potential to be used as phytoremediators. Translocation factors (TFs) were also estimated to determine the efficiency of the plants to translocate elements from root to shoot. Colocasia esculenta and Polygonum perfoliatum exhibited the highest BAF values, whereas Colocasia esculenta, Hedychium flavum, Phragmites karka, and Oenanthe javanica exhibited the highest TF values for most elements. Target hazard quotients (THQs) revealed potential health risks associated with one or more heavy metals in the plants, except for Zn, whose THQ values were below the level of concern in all the edible plant species. The hazard index (HI) signifying potential non-carcinogenic health risk from the combined effects of all the heavy metals was highest for Polygonum perfoliatum, indicating a potentially higher risk to health if this edible macrophyte is regularly consumed in higher quantities and may pose long-term health effects to the exposed population.

Transfer of lead through different trophic levels: Microalgae (Nannochloropsis oculata), rotifer (Brachionus plicatilis), and prawn (Macrobrachium rosenbergii)

Aquatic ecosystems suffer alterations by the input of several pollutants as potentially toxic elements which interact with the planktonic community with likelihood of bioconcentration, bioaccumulation, and biomagnification through the trophic chains despite the fact of being in low concentrations. The goal of this study involves assessing the toxicity, bioaccumulation, and transfer of the lead under controlled laboratory conditions by estimating the bioconcentration factor (BCF) and bioaccumulation factor (BAF) in organisms usually used in aquaculture, as Nannochloropsis oculata microalgae, Brachionus plicatilis rotifer, and the Malaysian prawn Macrobrachium rosenbergii. We assessed toxicity, bioconcentration, and transfer of the lead from the microalgae to higher trophic levels, the rotifer, and the prawn larvae. We performed three bioassays: (1) lead-exposed microalgae, (2) rotifer fed with lead-exposed microalgae, and (3) prawn larvae fed with either lead-exposed microalgae or rotifers fed with these microalgae. The toxicity endpoints were obtained for microalgae. The concentration of the lead in all organisms was analyzed by atomic absorption spectrophotometry for estimating BCF and BAF values. The endpoints No Observed Effect Concentration (NOEC) and Effective Concentration 50 (EC50) are 1 and 5.42 mg/L, respectively, for N. oculata. The BCF in the microalgae decreases as lead concentration increases. A BAF of 2948 in rotifers, and a BAF of 42.1 in prawns were obtained. In conclusion, lead can concentrate in microalgae, transfer, and accumulate through consumption toward the consecutive trophic levels, but not among invertebrates due to their detoxification mechanisms.