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Indole-3-acetic acid (IAA) can regulate plant growth and thus modulate the accumulation of polycyclic aromatic hydrocarbons (PAHs). However, the effect of endogenous IAA on PAHs accumulation and its influencing factors remains unclear. To unravel this, two different IAA expression genotypes of Arabidopsis thaliana, i.e., IAA-underproducing yucca1D [YUC1] mutant and wild type [WT]) were selected and treated with different fluoranthene (Flu) concentrations (0 mg/L [CK], 5 mg/L [Flu5], and 20 mg/L [Flu20]) to reveal the impact mechanism of endogenous IAA on Flu uptake by plants. The results indicated that under Flu5 treatment, the bioconcentration factors (BCF) and translocation factors (TF) of Flu in WT were 41.4 % and 14.3 % higher than those in YUC1. Similarly, under Flu20 treatment, the BCF and TF of Flu in WT were also 42.2 % and 8.2 % higher than those in YUC1. In addition, the BCF and TF were 72.5 % and 35.8 % higher under Flu5 treatment compared to Flu20 treatment for WT, and 73.4 % and 28.6 % higher respectively for YUC1. Moreover, WT exhibited higher plant growth (biomass, root morphology indicators [root length, root area and number of tips]) and IAA content compared to YUC1 under identical Flu treatments. Plant growth and IAA content declined with the increase of Flu concentration in both YUC1 and WT leaves compared with CK treatment. Conversely, in WT roots, root biomass and morphology indicators promoted followed by a decrease as the concentration of Flu increased. Additionally, the antioxidant enzyme activities (SOD, POD, and CAT) of WT were 11.1 %, 16.7 %, and 28.9 % higher than those of YUC1 under Flu5 treatment, and 13.6 %, 12.9 %, and 26.5 % higher under Flu20 treatment. Compared with CK treatment, SOD and POD activities promoted with increasing Flu concentration, whereas CAT activities decreased. Variability separation analysis revealed that level of IAA primarily influenced Flu accumulation in WT or under Flu5 treatments, whereas antioxidant enzyme activity primarily affected Flu accumulation in YUC1 or under Flu20 treatments. Exploring the relationship between the IAA synthesis gene YUCCA and IAA levels, alongside Flu accumulation, could yield novel insights into the regulation of PAH accumulation in plants.

Nowadays, the risk of pesticides to the environment and human health arises with its increasing applications. Bioconcentration Factor (BCF) is utilized to evaluate the potential plant contamination by pesticides from the soil. Large-scale BCF mapping is significant to urban planning, yet it remains challenging. To address this issue, this study integrates the plant uptake model with remote sensing techniques to map BCF considering various land surface properties. Two simplified approaches were developed: the first involves relative humidity and air temperature (RA-model), while the second uses plant transpiration (PT-model). To evaluate these models, BCF mappings generated by each approach were compared and found to be consistent in space and time, with R2 at 0.68 over the continental U.S. Both approaches showed that the eastern part of the U.S. had higher BCF values than the west throughout the year, with an annual cycle of BCF where the highest values occurred in summer and the lowest in winter. To further analyze the impact of BCF on human health, spatial heterogeneity detection was used to examine seven diseases at the county scale. The results suggest that BCF may explain the incidence of spatial heterogeneity of most diseases, specifically high blood pressure (q-value >0.3). Overall, this study demonstrates the potential of integrating plant uptake modeling with remote sensing to map BCF and provides insight into the impact of BCF on human health.

Tetrabromobisphenol A bis (allyl ether) (TBBPA-BAE) is an extensively used brominated flame retardant, which has raised considerable concern because of its neurotoxic and endocrine disruption effects on aquatic organisms. However, previous studies mainly focused on the parent compound before modification, tetrabromobisphenol A (TBBPA), and little information is available about the bioconcentration and biotransformation of TBBPA derivatives in fish. In this study, we investigated the tissue-specific uptake, elimination kinetic, and biotransformation of TBBPA-BAE in common carp (Cyprinus carpio). The fish were exposed to TBBPA-BAE at environmentally relevant concentrations (20 μg·L−1) for 28 days, followed by 14 days of depuration. The results showed TBBPA-BAE could rapidly accumulate in common carp. Among the seven tissues studied, the highest concentrations of TBBPA-BAE were observed in the liver (6.00 μg·g−1 wet weight [ww]) on day 24, while the longest residence time was observed in the kidney (t1/2 values of 18.7 days). Biotransformation of TBBPA-BAE was documented in the in vivo experiments, and 14 different phase I and phase II metabolites were identified in the liver. These findings suggest the biotransformation products of TBBPA-BAE should be considered for a comprehensive risk evaluation. [ABSTRACT FROM AUTHOR]

Antibiotics reach agricultural soils via fertilization with manure and biosolids as well as irrigation withwastewater and have the potential to be taken up by growing crops. The fate of antibiotics in terms of uptakefrom soil to plants, as well as translocation from root to leaves, is determined by a combination of antibiotic’sphysio-chemical (e.g. speciation, lipophilicity), soil (e.g. organic carbon content, pH) and plant (e.g.transpiration rates) characteristics. In this meta-analysis, a literature search was executed to obtain an overview of antibiotic uptake to plants, with an aim to identify uptake and translocation patterns of different antibiotic classes. Overall, we found that higher uptake of tetracyclines to plant leaves was observed compared to sulfonamides. Differences were also observed in translocation within the plants, where tetracyclines were found in roots and leaves with close to equal concentrations, while the sulfonamides represented a tendency to accumulate to the root fraction. The antibiotic’s characteristics have a high influence on their fate, for example, the high water-solubility and uncharged speciation in typical agricultural soil pH ranges likely induces tetracycline uptake from soil and translocation in plant. Despite the advances in knowledge over the past decade, our meta-analysis indicated that the available research is focused on a limited number of analytes and antibiotic classes. Furthermore, fastgrowing plant species (e.g. spinach, lettuce, and radish) are overly represented in studies compared to crop species with higher significance for human food sources (e.g. corn, wheat, and potato), requiring more attention in future research.

Globally, urbanization, industrialization, and transportation have worsened urban air quality in recent decades. Using sustainable, cost-effective methods to monitor and reduce air pollution is crucial. The best Nature-based Solution (NbS) for urban environmental cleanup is plants. Roadside plants are key carriers of air pollution and have various tolerances. Ziziphus spina-christi's air pollution tolerance was assessed using the Air Pollution Tolerance Index (APTI). The Bioconcentration Factor (BCF) examined the heavy metal accumulation capacity of Ziziphus spina-Christi's fruits and leaves. Two sampling sites were studied: a reference location remote from human activity and a densely populated metropolitan region. Ziziphus spina-christi is considered a tolerant species in Qatar, based on its calculated value of APTI in this study. Both total chlorophyll and ascorbic acid influence APTI levels and have a strong positive correlation with APTI. BCF values in leaves were higher than fruits indicating that the leaves of Ziziphus spina-christi have a greater potential for metal absorption than its fruits. Moreover, the leaves of Ziziphus spina-christi showed a potential for mercury accumulation (BCF > 1), thus it is a good candidate to be used for phytoremediation in areas of mercury contamination. The integration of both APTI and BCF methods is significant and beneficial in advising policymakers and urban planners regarding suitable tree species for sustainable urban development. [ABSTRACT FROM AUTHOR]

Phenolic benzotriazoles (BTZs) are used globally as light stabilizers in various plastic products to protect them from photooxidative degradation. The same physical–chemical properties that confer their functionality, like a sufficient photostability and a high octanol–water partition coefficient, also raise concerns on their potential for environmental persistence and bioaccumulation based on in silico predictive tools. To evaluate their bioaccumulation potential in aquatic organisms, standardized fish bioaccumulation studies according to OECD TG 305 were conducted with four of the most commonly used BTZs: UV 234, UV 329, UV P, and UV 326. The resulting growth‐ and lipid‐corrected BCF values revealed that UV 234, UV 329, and UV P were below the bioaccumulation threshold (BCF ≤ 2000), but UV 326 is considered very bioaccumulative (BCF ≥ 5000) with respect to the bioaccumulation criteria under REACH. Comparing these experimentally derived data with quantitative structure activity related or other calculated values using a logarithmic partitioning coefficient octanol–water (log Pow) driven mathematical formula revealed significant discrepancies demonstrating the weakness of current in silico approaches for this group of substances. Furthermore, available environmental monitoring data demonstrate that these rudimentary in silico approaches can lead to unreliable bioaccumulation estimates for this chemical class due to considerable uncertainties in underlying assumptions (e.g., concentration and route of exposure). However, using more sophisticated in silico methods (i.e., CATALOGIC base‐line model), the derived BCF values were better aligned with the experimentally derived ones. This paper studies the routing algorithms in the low earth orbit satellite network. Considering that the evaluation of inter‐satellite links in previous studies is relatively simple and the security of data transmission paths is poor, a linear programming routing algorithm based on a mathematical model and a multi‐object optimization Dijkstra algorithm are proposed. The simulation results show that they perform well in many respects. [ABSTRACT FROM AUTHOR]

Chinese brake fern (Pteris vittata) can increase tolerance to arsenic (As) and cadmium (Cd) toxicity by regulating rhizosphere microbial diversity. However, effects of combined As–Cd stress on microbial diversity and plant uptake and transport remain poorly understood. Therefore, effects of different concentrations of As and Cd on Pteris vittata (P. vittata) metal uptake and translocation and rhizosphere microbial diversity were examined in a pot experiment. The results indicated that As primarily accumulated aboveground in P. vittata (bioconcentration factor (BCF) ≤ 51.3; translocation factor (TF) ≈ 4), whereas Cd primarily accumulated belowground (BCF ≤ 39.1; TF < 1). Under single As, single Cd, and As–Cd combined stress, the most dominant bacteria and fungi were Burkholderia-Caballeronia-P (6.62–27.92%) and Boeremia (4.61–30.42%), Massilia (8.07–11.51%) and Trichoderma (4.47–22.20%), and Bradyrhizobium (2.24–10.38%) and Boeremia (3.16–45.69%), respectively, and their abundance ratios had a significant impact on the efficiency of P. vittata for As and Cd accumulation. However, with increasing As and Cd concentrations, abundances of plant pathogenic bacteria such as Fusarium and Chaetomium (the highest abundances were 18.08% and 23.72%, respectively) increased, indicating that As and Cd concentrations reduced P. vittata resistance to pathogens. At high soil concentrations of As–Cd, although plant As and Cd contents increased and microbial diversity was highest, enrichment efficiency and transportability of As and Cd decreased substantially. Therefore, pollution intensity should be considered when evaluating P. vittata suitability for phytoremediation of combined As–Cd contaminated soils. [ABSTRACT FROM AUTHOR]

Mercury contamination from human activities is a severe environmental problem. The low cost of rhizofiltration of heavy metal-contaminated environments is causing an increasing interest in these technologies. The present study demonstrates the effectiveness of mercury removal from water by phytoremediation using S. natans. Plants cultured and collected from the environment were used. The study used Hoagland's liquid medium contaminated with mercury: 0.15, 0.20, and 0.30. The bioconcentration factor obtained was 275–780. The relative growth rate was up to 0.12 g/gd and was much better for cultured plants than those collected from the environment. The removal rate of toxic metal was up to 94%. Total protein increased for cultures plants by up to 84%, while it decreased by up to 30% for those taken from the environment. Total chlorophyll for cultured plants decreased by up to 54%, which could be due to the toxic effect of the metal. [ABSTRACT FROM AUTHOR]

Landfill sites open and close frequently throughout the world, taking over a significant amount of land and leaving it contaminated and unavailable to the surrounding population for use. Different forms of remediation methods have been employed to rehabilitate contaminated land to a state that poses less of a threat to the environment. Phytoremediation is one of the remediation techniques that has proven to be effective, economical and easier to implement compared to other methods. The main aim of this study was to explore the potential use of Lolium perenne L. to remediate and restore metal-contaminated landfill soil and determine its stress tolerance mechanism(s). The metal uptake, determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and inductively coupled plasma-mass spectroscopy (ICP-MS), revealed that Lolium perenne accumulate a higher amount of metals in the roots than in leaves, which was further confirmed by the translocation factor (TF) values of all of the metals that were below 1, ranging between 0.2 and 0.8, while Cu, Cr and Pb had a bioaccumulation factor (BCF) > 1. This confirms that L. perenne is capable of absorbing metals into the root matrix but might restrict further movement into other parts of the plant as a defense mechanism against metal toxicity. In response to metal-induced stress, L. perenne displayed an increase in enzyme activity of superoxide dismutase, glutathione S-transferase, peroxidase and amylases in plants grown in landfill soil. Peroxidases displayed the highest level of enzyme activity, while total amylolytic activity had the most significant increase in activity over time. Although not a hyperaccumulator, L. perenne is a potential candidate for the phytoremediation of landfill soil and the phytostabilization of Cu, Cr and Pb. [ABSTRACT FROM AUTHOR]

Synthetic pyrethroid insecticides (SPIs) are frequently detected in water bodies and sediments, and they show high toxicity to aquatic organisms, but their toxicity kinetics remain unknown. In this work, the kinetics of uptake and depuration of three SPIs, fenpropathrin (FP), cypermethrin (CM) and deltamethrin (DM) were evaluated in manila clams (Ruditapes philippinarum) for the first time through a bioconcentration-semi-static test. Clams were exposed to three SPIs of different concentrations (2 ng/mL and 20 ng/mL) for 4 days, followed by a 10-day depuration stage. The results indicated that adult manila clams could absorb SPIs rapidly, and the bioconcentration factor (BCF) values of SPIs were different at high and low concentrations of contaminants. The depuration rate constants (k2) of SPIs in adult manila clams ranged from 0.024 h-1 to 0.037 h-1. The bioaccumulation factors ranged from 319.41 to 574.38. And the half-lives (t1/2) were in the range of 18.49 to 29.22 h. These results showed that manila clams have a high bioconcentration capacity, and SPIs have a high cumulative risk for bivalves. Moreover, after 10 days of elimination, SPIs can still be detected in manila clams at all concentrations, indicating that the complete elimination of SPIs required a longer time. [ABSTRACT FROM AUTHOR]

Organophosphorus compounds have toxic effects on organisms and the ecosystem. Therefore, it is vital to monitor and control the effluent organophosphorus levels of wastewater treatment plants (WWTPs). This study analyzed the composition and concentration of organophosphorus compounds from the upstream enterprises of a WWTP and conducted ecological risk and toxicity assessments using ECOSAR (ecological structure activity relationship model), T.E.S.T (Toxicity Estimation Software Tool), and risk quotient (RQ) methods. A total of 14 organic phosphorus pollutants were detected in the effluent of the upstream enterprises and WWTP. The concentration of influent total organic phosphorus from the WWTP was 39.5 mg/L, and the effluent total organic phosphorus was merely 0.301 mg/L, indicating that good phosphorus removal was achieved in the WWTP. According to the acute and chronic toxicity analysis, the ECOSAR ecotoxicity assessment showed that 11 kinds of organophosphorus compounds were hazardous to fish, daphnia, and algae in different degrees. Among them, triphenyl phosphine (TPP) had a 96 hr LC50 of 1.00 mg/L for fish and is a substance with high acute toxicity. T.E.S.T evaluates the acute toxicity of each organophosphorus component and the bioconcentration factor (BCF). The evaluation results showed that the LC50 of TPP and octicizer were 0.39 and 0.098 mg/L, respectively, and the concentrations of these two organophosphorus compounds from the effluent of an environmental protection enterprise were as high as 30.4 mg/L and 0.735 mg/L, which exceeded the acute toxicity values and has led to serious hazards to aquatic organisms. The BCF values of each organophosphorus component in the upstream enterprises and the effluent of the WWTP were less than 2000, implying that there was no bioaccumulation effect on aquatic organisms. The developmental toxicity assessment demonstrated that there were nine types of organophosphorus compounds belonging to developmental toxicants, that the presence of developmental toxicants was found in the effluent of each upstream enterprise, and that triethyl phosphate (TEP) was the most common organophosphorus compound. Comparing the RQ of the effluent from various enterprises, it was found that the effluent from the environmental protection enterprise presented the highest degree of environmental hazard, mainly due to the higher toxicity of TEP and octicizer. [ABSTRACT FROM AUTHOR]

Indole-3-acetic acid (IAA) can regulate plant growth and thus modulate the accumulation of polycyclic aromatic hydrocarbons (PAHs). However, the effect of endogenous IAA on PAHs accumulation and its influencing factors remains unclear. To unravel this, two different IAA expression genotypes of Arabidopsis thaliana , i.e. , IAA-underproducing yucca1D [YUC1] mutant and wild type [WT]) were selected and treated with different fluoranthene (Flu) concentrations (0 mg/L [CK], 5 mg/L [Flu5], and 20 mg/L [Flu20]) to reveal the impact mechanism of endogenous IAA on Flu uptake by plants. The results indicated that under Flu5 treatment, the bioconcentration factors (BCF) and translocation factors (TF) of Flu in WT were 41.4 % and 14.3 % higher than those in YUC1. Similarly, under Flu20 treatment, the BCF and TF of Flu in WT were also 42.2 % and 8.2 % higher than those in YUC1. In addition, the BCF and TF were 72.5 % and 35.8 % higher under Flu5 treatment compared to Flu20 treatment for WT, and 73.4 % and 28.6 % higher respectively for YUC1. Moreover, WT exhibited higher plant growth (biomass, root morphology indicators [root length, root area and number of tips]) and IAA content compared to YUC1 under identical Flu treatments. Plant growth and IAA content declined with the increase of Flu concentration in both YUC1 and WT leaves compared with CK treatment. Conversely, in WT roots, root biomass and morphology indicators promoted followed by a decrease as the concentration of Flu increased. Additionally, the antioxidant enzyme activities (SOD, POD, and CAT) of WT were 11.1 %, 16.7 %, and 28.9 % higher than those of YUC1 under Flu5 treatment, and 13.6 %, 12.9 %, and 26.5 % higher under Flu20 treatment. Compared with CK treatment, SOD and POD activities promoted with increasing Flu concentration, whereas CAT activities decreased. Variability separation analysis revealed that level of IAA primarily influenced Flu accumulation in WT or under Flu5 treatments, whereas antioxidant enzyme activity primarily affected Flu accumulation in YUC1 or under Flu20 treatments. Exploring the relationship between the IAA synthesis gene YUCCA and IAA levels, alongside Flu accumulation, could yield novel insights into the regulation of PAH accumulation in plants. [Display omitted] • Bioconcentration factor (BCF) of WT was higher than that of YUC1 under identical Flu treatments. • BCF was higher under Flu5 treatment than under Flu20 treatment in the same genotypes. • Transpiration rate can influence Flu transport in Arabidopsis thaliana. • IAA was the key factor for Flu accumulation in WT or under Flu5 treatment. • Antioxidant enzyme activity was important for Flu accumulation in YUC1 or under Flu20 treatment. [ABSTRACT FROM AUTHOR]

Landfill sites open and close frequently throughout the world, taking over a significant amount of land and leaving it contaminated and unavailable to the surrounding population for use. Different forms of remediation methods have been employed to rehabilitate contaminated land to a state that poses less of a threat to the environment. Phytoremediation is one of the remediation techniques that has proven to be effective, economical and easier to implement compared to other methods. The main aim of this study was to explore the potential use of Lolium perenne L. to remediate and restore metal-contaminated landfill soil and determine its stress tolerance mechanism(s). The metal uptake, determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and inductively coupled plasma-mass spectroscopy (ICP-MS), revealed that Lolium perenne accumulate a higher amount of metals in the roots than in leaves, which was further confirmed by the translocation factor (TF) values of all of the metals that were below 1, ranging between 0.2 and 0.8, while Cu, Cr and Pb had a bioaccumulation factor (BCF) > 1. This confirms that L. perenne is capable of absorbing metals into the root matrix but might restrict further movement into other parts of the plant as a defense mechanism against metal toxicity. In response to metal-induced stress, L. perenne displayed an increase in enzyme activity of superoxide dismutase, glutathione S-transferase, peroxidase and amylases in plants grown in landfill soil. Peroxidases displayed the highest level of enzyme activity, while total amylolytic activity had the most significant increase in activity over time. Although not a hyperaccumulator, L. perenne is a potential candidate for the phytoremediation of landfill soil and the phytostabilization of Cu, Cr and Pb.

Chromium (Cr) is a dangerous industrial pollutant that harms surface water resources and is associated with serious adverse health effects that eventually lead to mortality. In present study Cr concentrations were detected spectrophotometrically by atomic absorption spectrophotometer from October 2018 to October 2020 (in the month of October, January, April, and July) in abiotic (water and sediment) and biotic [plant (Eichhornia crassipes (Mart.) Solms) and fish (Labeo rohita)] components of Yamuna River ecosystem. Samples were collected from Vihar Ghat (Vrindavan), Mathura -- 27.58387, 77.69317 (i.e., M2 site), 100 m upstream (M1 site) and downstream (M3 site) and from Renuka Ghat, Agra -- 27.25190, 77.87535, India (i.e., N2 site), 100 m upstream (N1 site) and downstream (N3 site). Root, stem and leave of studied plant while gill, muscle, liver, and kidney samples of fish were used for determination of Cr toxicity. Results revealed higher concentration of Cr in water throughout the study when compared with permissible limits by WHO and BIS (0.05 mg/L). While sediment sample had the highest metal content with a mean concentration of 51.3 ± 2.34 mg/L in summer 2019. The Heavy Metal Pollution Index for water, sediment, plant and fish samples at Mathura sampling site were shown to be extremely high, that is, 2,555; 31,254; 269 and 2,600 respectively, when compared to the samples from Agra sampling site. The bioconcentration factor in fish tissues was highest in gills (6.4167 in post-monsoon 2018 at Agra), and lowest in kidney (1.0417 in winters 2020 at Mathura). Such studies pave the path for future to establish the highest risk in term of time and components in the river ecosystem for their utility. Besides, such approaches and findings will help policy makers to ensure a safe and sustainable environment in terms of socioeconomics and human health aspects. [ABSTRACT FROM AUTHOR]

Pyrethroids pesticides (PPs) are the widely adopted synthetic pesticides for agriculture and fishery. The frequent use of these pesticides leads to the accumulation of residues in the freshwater environments in China, subsequently affecting aquatic organisms and ecosystems. However, there are few reports on the toxicological and risk assessment of aquaculture aquatic products. In this study, the uptake, depuration kinetics and potential risk to human health and ecology of fenpropathrin, cypermethrin, fenvalerate, and deltamethrin were assessed using tilapia. The results indicated that four PPs were readily accumulated by tilapia. The bioconcentration factors (BCF) of the PPs in plasma and muscle were between 71.3 and 2112.1 L/kg and 23.9–295.3 L/kg, respectively. The half-lives (t1/2) of muscle and plasma were 2.90–9.20 d and 2.57–8.15 d. The risks of PPs residues in the muscle of tilapia and exposed water were evaluated by hazard quotient (HQ) and risk quotient (RQ). Although PPs residues in tilapia had a low dietary risk to human health, the residues in the exposed water had a high ecological risk to fish, daphnia, and green algae. Therefore, assessing the PPs content in freshwater aquaculture and monitoring their dosages and frequencies are highly necessitated to avoid their adverse effect on the aquaculture environment.

In the European Medicines Agency (EMA) "Guideline for Environmental Risk Assessment of Medicinal Products for Human Use," a fish bioconcentration factor (BCF) study is triggered in Phase I for pharmaceuticals having log Kow >4.5, to support Persistence, Bioaccumulation and Toxicity (PBT) screening, and in Phase II to assess secondary poisoning and bioaccumulation ('B') potential when log Kow ≥3. The standard sampling schedule outlined in OECD Test Guideline 305 (TG305) may require assessment of approximately 200 fish following exposure to low- and high-test concentrations and a negative control. We report experimental log Kow and BCF values for 64 human pharmaceuticals that were used to evaluate the current BCF testing trigger of log Kow ≥3, and whether a single BCF exposure concentration allows accurate classification of bioaccumulation potential. Our data support raising the BCF testing trigger to log Kow ≥4, and use of a single test concentration. The resulting reduction in the use of fish is consistent with the 3 R s principle and did not adversely affect classification accuracy. An assessment of potential risk of secondary poisoning was also conducted for three drugs classified as either B or vB, and no risks were identified. • Log Kow and BCF data are evaluated for 64 human pharmaceuticals. • The data support raising the trigger for BCF testing to log Kow ≥4. • No meaningful difference between BCF values determined in OECD 305 studies at high and low exposure concentrations. • Analysis of the data support 3 R s efforts to revise BCF testing criteria to reduce the use of fish. • The presence of halogens in an API is not a good predictor of bioaccumulation potential. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a heavy metal that is very dangerous and toxic. Melawi River, a river with a length of 471 m, passes through four districts namely Menukung, Ella Hulu, Ella Hilir, and Nanga Pinoh which are the main water transportation routes in Melawi regency. This research was aimed to determine the concentration of mercury in water, sediments and Lais (Kryptopterus) fish of mercury bioconcentration factors, and the safety level of consumption the contaminated Lais (Kryptopterus) fish. The mercury measurement using Atomic Absorption Spectroscopy (AAS) showed that the average concentration of mercury found in the water was 1.80×10-4 ppm, sediments 1.33×10-2 ppm, and Lais fish 0.291 ppm. Meanwhile, the average bioconcentration factor (BCF) of mercury in Lais fish was 1.677 ppm. The maximum daily consumption of Lais fish that were safe for the community consumption at the Melawi watershed was 0,026 kg /day for adults and 0.006 kg/day for the children

Organophosphorus compounds have toxic effects on organisms and the ecosystem. Therefore, it is vital to monitor and control the effluent organophosphorus levels of wastewater treatment plants (WWTPs). This study analyzed the composition and concentration of organophosphorus compounds from the upstream enterprises of a WWTP and conducted ecological risk and toxicity assessments using ECOSAR (ecological structure activity relationship model), T.E.S.T (Toxicity Estimation Software Tool), and risk quotient (RQ) methods. A total of 14 organic phosphorus pollutants were detected in the effluent of the upstream enterprises and WWTP. The concentration of influent total organic phosphorus from the WWTP was 39.5 mg/L, and the effluent total organic phosphorus was merely 0.301 mg/L, indicating that good phosphorus removal was achieved in the WWTP. According to the acute and chronic toxicity analysis, the ECOSAR ecotoxicity assessment showed that 11 kinds of organophosphorus compounds were hazardous to fish, daphnia, and algae in different degrees. Among them, triphenyl phosphine (TPP) had a 96 hr LC50 of 1.00 mg/L for fish and is a substance with high acute toxicity. T.E.S.T evaluates the acute toxicity of each organophosphorus component and the bioconcentration factor (BCF). The evaluation results showed that the LC50 of TPP and octicizer were 0.39 and 0.098 mg/L, respectively, and the concentrations of these two organophosphorus compounds from the effluent of an environmental protection enterprise were as high as 30.4 mg/L and 0.735 mg/L, which exceeded the acute toxicity values and has led to serious hazards to aquatic organisms. The BCF values of each organophosphorus component in the upstream enterprises and the effluent of the WWTP were less than 2000, implying that there was no bioaccumulation effect on aquatic organisms. The developmental toxicity assessment demonstrated that there were nine types of organophosphorus compounds belonging to developmental toxicants, that the presence of developmental toxicants was found in the effluent of each upstream enterprise, and that triethyl phosphate (TEP) was the most common organophosphorus compound. Comparing the RQ of the effluent from various enterprises, it was found that the effluent from the environmental protection enterprise presented the highest degree of environmental hazard, mainly due to the higher toxicity of TEP and octicizer.

The management of phosphogypsum (PG) heap, located south of the Sfax city in Tunisia, has been going on for decades. But dumping this solid waste still poses environmental problems. Even though valorized as amendment to agriculture soils, the sanitary impact of this practice is not seriously considered. To assess the risk of the transference of contaminants from PG to agricultural soil-plants food chain, a wild plant species Salicornia arabica grown in PG-contaminated field and tomato (Lycopersicon esculentum) and oat (Avena sativa) grown in laboratory using different rates (10, 20 and 30%) of PG amendment, were tested. The cadmium, lead, chromium, nickel, copper and zinc concentrations in soils and plants were determined by atomic absorption spectrometry and by inductively coupled plasma-mass spectrometry, respectively. Measurements showed that Ni, Cu and Pb levels in the amended soils were below international standards except for Cd and Cr which exceeded Chinese, FAO/WHO and European allowable standard limits. Gathered results showed that the more the PG rate increases, the more the bioconcentration factors of heavy metals increased in plants, particularly in the roots. This is a prospective study assuming direct or indirect exposure scenario of different human cohorts by consuming varied common food stuffs. The Human Exposure to Soil Pollutants evaluation and United State Environment Protection Agency models were adopted for the hazard quotient calculation to assess the acceptability of sanitary risk related to each metal. The direct and indirect health risk assessments varied in the decreasing order: children, adolescents and then adults. Therefore, the PG amendment must not exceed the rate of 10%. [ABSTRACT FROM AUTHOR]

Antibiotics reach agricultural soils via fertilization with manure and biosolids as well as irrigation withwastewater and have the potential to be taken up by growing crops. The fate of antibiotics in terms of uptakefrom soil to plants, as well as translocation from root to leaves, is determined by a combination of antibiotic'sphysio-chemical (e.g. speciation, lipophilicity), soil (e.g. organic carbon content, pH) and plant (e.g.transpiration rates) characteristics. In this meta-analysis, a literature search was executed to obtain an overview of antibiotic uptake to plants, with an aim to identify uptake and translocation patterns of different antibiotic classes. Overall, we found that higher uptake of tetracyclines to plant leaves was observed compared to sulfonamides. Differences were also observed in translocation within the plants, where tetracyclines were found in roots and leaves with close to equal concentrations, while the sulfonamides represented a tendency to accumulate to the root fraction. The antibiotic's characteristics have a high influence on their fate, for example, the high water-solubility and uncharged speciation in typical agricultural soil pH ranges likely induces tetracycline uptake from soil and translocation in plant. Despite the advances in knowledge over the past decade, our meta-analysis indicated that the available research is focused on a limited number of analytes and antibiotic classes. Furthermore, fastgrowing plant species (e.g. spinach, lettuce, and radish) are overly represented in studies compared to crop species with higher significance for human food sources (e.g. corn, wheat, and potato), requiring more attention in future research., (Copyright 2024 Inna Nybom, Thomas D. Bucheli , Gina Garland. License: This work is licensed under a Creative Commons Attribution 4.0 International License.)

Immobilized Artificial Membrane (IAM) chromatography constitutes a valuable tool for medicinal chemists to prioritize drug candidates in early drug development. The retention on IAM stationary phases encodes lipophilicity, electrostatic and other secondary interactions contrary to traditional octanol-water partitioning. An increasing number of publications in recent years have suggested that IAM indices, including isocratic log k(IAM) or extrapolated log kw(IAM) retention factors, chromatographic hydrophobicity index CHI(IAM) or the polarity parameter Δlog kw(IAM) can successfully model the passage of xeniobiotics through biological membranes and barriers and predict pharmacokinetic properties, often in combination with additional descriptors. Examples referring to the modeling of human oral absorption, blood-brain penetration and skin partition are described. More recently, IAM chromatography has been applied to estimate toxicological endpoints in regard to drug safety, such as phospholipidosis potential, or in regard to chemical risk hazards including the bioconcentration factor and aquatic organisms’ toxicity. The promising results in both medicinal chemistry and in environmental science in combination with the speed, reproducibility and low analyte consumption suggest that a broader application of IAM chromatography in the early drug discovery process and in ecotoxicity may save time and money in initial drug candidate selection and will contribute to a reduced risk hazard of chemicals.

Mercury (Hg) is a heavy metal that is very dangerous and toxic. Melawi River, a river with a length of 471 m, passes through four districts namely Menukung, Ella Hulu, Ella Hilir, and Nanga Pinoh which are the main water transportation routes in Melawi regency. This research was aimed to determine the concentration of mercury in water, sediments and Lais (Kryptopterus) fish of mercury bioconcentration factors, and the safety level of consumption the contaminated Lais (Kryptopterus) fish. The mercury measurement using Atomic Absorption Spectroscopy (AAS) showed that the average concentration of mercury found in the water was 1.80x10-4 ppm, sediments 1.33x10-2 ppm, and Lais fish 0.291 ppm. Meanwhile, the average bioconcentration factor (BCF) of mercury in Lais fish was 1.677 ppm. The maximum daily consumption of Lais fish that were safe for the community consumption at the Melawi watershed was 0,026 kg /day for adults and 0.006 kg/day for the children. [ABSTRACT FROM AUTHOR]

Arsenic (As) can be transferred from soil and accumulated in food plants. So far, we have a knowledge gap about transference of As from agricultural soils to wheat plant in the natural polluted environment. The aim of present study was to investigate As transfer from soil to different tissues of wheat at a highly As polluted area. In this regard, the mobility indices were used to explain As transfer and accumulation from soil to wheat plant. Moreover, the relationships between soil properties including soil As content, pH, cation‐exchange capacity (CEC), electrical conductivity (EC), organic matter (OM), Fe, and Al percentage with As concentrations in wheat root, straw, and grain were investigated. Finally, the potential health risks of As exposure to humans through consumption of the local wheat crops were assessed. According to the results, harmful degree of As was accumulated in different parts of wheat plant. The impact of different soil properties on As accumulation in wheat was found to be as follows: soil As content > Al% > Fe% > OM > pH > CEC > EC. High carcinogenic and noncarcinogenic risks in all age groups of consumers were found. The minimum and maximum values for target hazard quotient and excess lifetime cancer risk were found to be 1.22, 102.97 and 0.000061, 0.33, respectively. These findings strongly support the notion that As can be entered to food chain through agricultural products cultivated in polluted soils. [ABSTRACT FROM AUTHOR]

Phytoremediation potential of duckweeds (Lemna minuta, Lemna minor) to remove nutrients from simulated wastewater was analyzed. In two separate experiments, the two species were grown for 28 days in waters enriched with nitrate and phosphate to simulate nutrient concentrations of domestic wastewater. Water physical and chemical measurements (temperature, pH, conductivity, oxygen) and plant physiological and biochemical analysis (biomass, relative growth rate–RGR, nutrient and chlorophyll contents, peroxidative damage, bioconcentration factor–BCF) were made to test and compare the phytoremediation capacity of the two Lemna species. L. minuta biomass increased almost tenfold during the time-course of the treatment resulting in a doubling of the mat thickness and a RGR of 0.083 ± 0.001 g/g day. Maximum frond content of phosphate was reached by day 21 (increase over 165%) and nitrate by day 7 (10%). According to the BCF results (BCF > 1000), L. minuta was a hyperaccumulator for both nutrients. On the other hand, L. minor biomass and mat thickness decreased continuously during incubation (RGR = − 0.039 ± 0.004 g/g day). In L. minor fronds, phosphate content increased until day 14, after which there was a decrease until the end of the incubation. Frond nitrate content significantly decreased by day 7, but then remained relatively constant until the end of the experiment. L. minor proved to be hyperaccumulator for phosphates, but not for nitrates. Results indicated L. minuta has a greater potential than L. minor to remove both nutrients by bioaccumulation, especially phosphates, demonstrated also by better physiological and biochemical responses. However, during the incubation, the chlorophyll content of L. minuta mat did continuously decrease and peroxidative damage had increased until day 14, indicating that the system was under some kind of stress. Strategies to avoid this stress were discussed. [ABSTRACT FROM AUTHOR]

Pot experiments were conducted to study the effects of different cadmium (Cd) levels (0, 75, 150, 300 and 600 mg kg−1) on the growth, cadmium concentration and cadmium accumulation of two varieties of ryegrass, and the correlation between plant cadmium concentration and soil cadmium chemical forms. The results showed that root dry weight of the two varieties of ryegrass, dry weight of shoot and plant in Aubade increased first and then decreased with the increase of soil cadmium. When the soil cadmium level was 75 mg kg−1, shoot dry weight and plant dry weight in Aubade reached the maximum (10.92 g pot−1 and 12.03 g pot−1), which was 11.13% and 10.67% higher than that of the control respectively. The cadmium form in shoot of the two ryegrass varieties was dominated by was sodium chloride extraction (F-NaCl), followed by deionized water extracted (F-W) and acetic acid extracted (F-HAC). The cadmium forms in soils were mainly exchangeable (EXC-Cd), and cadmium concentrations of leaf, stem and root were significantly positively correlated with exchangeable cadmium content in the rhizosphere soil (P < 0.01). The EXC-Cd content in Abbott soil was higher than that in Bond, which was consistent with Abbott's Cd absorption above Bond. The cadmium transport factor of the two ryegrass varieties were less than 1, and cadmium bioconcentration factor were all greater than 1. In comparison of the two ryegrass varieties, the dry weight of shoot and plant of Abbott were higher than that of Bond under the stress of 75–600 mg kg−1 Cd. The cadmium concentration and cadmium accumulation of shoot and root in Abbott were also higher than that of Bond. There was a genotypic difference in ryegrass tolerance to cadmium and cadmium absorption. Abbott was more suitable as a phytoremediation material for soil cadmium pollution. [ABSTRACT FROM AUTHOR]

Canadian goldenrod (Solidago canadensis L.) is a plant that grows in a variety of environmental conditions. It shows high capability to spread in various habitats, including fallow lands and brownfield land. The research aimed at analyzing the content of Pb and Zn in the underground (roots, rhizomes) and aboveground parts (stems, leaves, inflorences) of Solidago canadensis (SC) originating from two locations that are clearly different in terms of metal content in soil. Statistically significant differences were determined in the content of Pb and Zn in soil and particular morphological parts of the plant, depending on the sampling location. It has been shown that in the conditions of increased (compared with natural) Pb and Zn content in the soil, SC may serve as a bioaccumulator of these metals. It was determined that SC can be used as a phytostabilizer of Pb and Zn in soils heavily contaminated with these elements. The content of Zn in the aboveground parts of SC indicates that this plant can also be used for phytoextraction of soils contaminated with this metal. [ABSTRACT FROM AUTHOR]

The study discusses changes in lead contents in soil and crops after application of compost and fly ash. A three-year experiment was conducted on narrow-leaved lupine (Lupinus angustifolius L.), camelina (Camelina sativa L.) and oat (Avena sativa L.), which were grown on medium soil fertilised with compost or fly ash (FA). The lead amounts in various combinations were evaluated using sequential (BCR analysis) and single (DTPA solution) methods. The total contents of lead and amounts of selected macronutrients were assessed in the biomass of plants. The Pb contents in the soil and plants were used to calculate the risk assessment code (RAC), individual contamination factor (ICF), bioconcentration factor (BCF) and contamination coefficient level (CCL). Lower amounts of bioavailable Pb in the soil were observed as a result of compost and FA application. Fly ash immobilised Pb more effectively, as evidenced by the BCF and CCL values. The increase in the Pb contents in the sequentially separated fractions and in plant biomass were caused by applied compost or FA. The Pb contents in exchangeable forms decreased, whereas its contents in residual forms increased.

Present study deals with the effects of glyphosate-based herbicide, Excel Mera 71 on Anabas testudineus, Heteropnestes fossilis and Oreochromis niloticus in field conditions (1.85 kg/ha) based on anti-oxidative, metabolic and digestive responses. For this study following biomarkers viz., acetylcholinesterase (AChE), lipid peroxidation (LPO), catalase (CAT), glutathione-S-transferase (GST), alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), amylase, lipase and protease were investigated in gill, stomach, intestine, liver, kidney, brain, muscle and spinal cord of the concerned fish species. Enzyme activities were significantly altered by glyphosate exposure after 30 days, these activities were tissue as well as species specific. The results suggested that these biomarkers could be used to assess the ecological risks of glyphosate on fish. Bioaccumulation factor (BAF) studied in different aquatic natural macrophytes showed order of Alternanthera philoxeroides > Azolla pinnata > Lemna sp. (Minor) > Lemna sp. (Major) > Pistia stratiotes, while transfer factor (TF) showed the order of Pistia stratiotes > Alternanthera philoxeroides > Lemna sp. Bioconcentration factor (BCF) study showed maximum accumulation of glyphosate in liver, kidney or intestine, and minimum either in bone or stomach irrespective of fish species. An integrated biomarker response (IBR), which uses a battery of biomarkers to calculate the standardized scores for each biomarker responses ranging from physiological to biochemical/molecular responses, was evaluated by combining the multiple biomarkers into a single value to evaluate quantitatively the toxicological effects of glyphosate. In general, the multiple indices exhibited variations and A. testudineus was more affected than other fish species; maximum IBR value was observed for LPO and minimum in case of ALT. The order of integrated biomarkers caused by glyphosate treatment was recorded as follows: LPO > Amylase > CAT > AST > Protease > Lipase > ALP > GST > AChE > ALT for A. testudineus, LPO > AChE > AST > Protease > CAT > Amylase > Lipase > GST > ALP > ALT for H. fossilis and AChE > CAT > LPO > AST > Amylase > GST > Protease > ALP > Lipase > ALT for O. niloticus. Finally, IBR analysis is able to distinguish the variations between different parameters and might be a useful tool for the quantification of integrated responses induced by glyphosate toward fish.

Tapak River pollution that occurred for the last few years will lead to contamination of heavy metals in milkfish ponds located in Tapak area. This finding potentially causes the accumulation of heavy metals (lead and copper) in the water, sediments and organs (gills, liver and muscle) of milkfish and will affect fish productivity and food safety. This study related to the assessment of 2 (two) heavy metal accumulation in aquatic pond environment and the maximum limit of fish consumption based on Provisional Tolerable Weekly Intake (PTWI) and Estimated Weekly Intake (EWI) adopted from Turkmen (2009) and Elnabris (2013). The objectives of this study were to : (1) analyze the concentration factor of heavy metal in sediment and bioconcentration factor (BCF) of heavy metals in milkfish organ and (2) determine maximum tolerance limits for milkfish to be consumed. The concentration factor of heavy metal distribution in the sediments showed that the range of heavy metal content in the sediments was 1001.793± 143.573 – 6679.003±825.832 times compared to the heavy metal content in the column water. The calculation result of the average bioconcentration factor (BCF) of heavy metal (water) in each fish organ exhibited that Pb metal tended to be highly accumulative in all fish organs while Cu was low to high in accumulative. The BCF value of heavy metals (sediments) towards milkfish organ showed that Pb and Cu were slightly accumulative. The assessment results of EWI showed that the fish muscle was still suitable for adult consumption with a limit of 0.624 kg/week while the liver of milkfish was not suitable for consumption. Meanwhile, children were not allowed to consume milkfish from Tapak ponds.

The contamination of soils with metals applies, in particular, to areas related to industry, the mining of raw materials and ores, transport, and agriculture. Unlike organic materials, metals cannot degrade over time and need to be reduced, removed, or immobilized in soil. One of the remediation methods for soils contaminated with metals is phytoextraction, which uses plants’ ability to accumulate metals in their own tissues. Metals enter the plant organism through the roots and are transported to the aboveground parts, where they are accumulated. In this study, we evaluated the phytoaccumulative abilities of two plant species tested on soils from industrial areas contaminated with metals to different extents (Zn, Cd, Ni, Pb, Cr, and Cu). The research was conducted for three years under the conditions of a pot experiment. In order to obtain four soils with varying degrees of metal contamination, two soils from industrial areas, G1 (contaminated) and G2 (uncontaminated), were mixed in the following ratios: 1:1, 1:3, 1:7, and 1:9. In the phytoremediation process, Festuca rubra L. and Alyssum saxatile L. were tested. After analyzing the results of the bioconcentration factor (BCF) for the tested plants, it was noted that both of the tested plants accumulated Cd and Zn more easily, followed by Cu, Ni, and Cr, and then Pb to a lesser extent. The values of factors for Cd and Zn were correlated with the high mobility of these elements compared to other metals and their relatively easy uptake by plants. Alyssum saxatile L. has an ability to accumulate Cd compared to Festuca rubra L., which is confirmed by the BCF (0.764) and transfer factor (TF) (3.5) (for 1:7 combination) values. The calculated results for the BCFs for Alyssum saxatile L. are less than one for all tested metals, which allows us to state that Alyssum saxatile L. is not an accumulator.

Abstract Tannery effluents are rich source of chromium (Cr) and organic carbon (C), however, hexavalent Cr (Cr6+) is many-fold more toxic than trivalent Cr (Cr3+). We examined the extent of total Cr, Cr3+ and Cr6+ pollution of agricultural soils under long-term tannery effluent irrigation in Kasur, Pakistan. Effects of Cr species on morphological and physiological responses of wheat including patterns of Cr3+ and Cr6+ uptake, their translocation factor (TF) and bioconcentration factor (BCF) were studied. Nine soil samples had significantly variable total organic C and total Cr, Cr3+ and Cr6+ contents. Pot study showed that morphological characteristics of wheat were largely unaffected by total Cr, Cr3+ and Cr6+ contents, however, physiological responses including contents of chlorophyll a, chlorophyll b, total chlorophyll, carotenoids and total proteins; and chlorophyll a:b ratio were significantly affected by contents of Cr species. Results further suggested that the relationships between total Cr and physiological attributes of wheat were controlled by Cr6+ rather than Cr3+ contents and, hence, Cr3+:Cr6+ ratios determined the effects of Cr on wheat growth and development. Uptake, TF and BCF values for Cr3+ and Cr6+ showed significant variations and BCF values showed negative correlation with total organic C contents. Results of our study highlight the significance of understanding the effects of Cr species and Cr3+:Cr6+ ratios rather than the total Cr contents when assessing the Cr behavior in soils and its effects on plant growth, especially phytotoxicity of tannery-based organic fertilizers before its application in the field. Graphical abstract Image 1 Highlights • Contrasting effects of Cr3+ and Cr6+ on wheat morphology and physiology. • Cr3+ and Cr6+ concentrations in plant tissues varies with Cr3+:Cr6+ ratio. • Bioconcentration factor (BCF) of Cr species correlated negatively with total organic C. • Soil organic C regulated the dynamics of Cr3+:Cr6+ ratio. • Cr3+:Cr6+ ratio was more important to assess the effects of Cr on wheat. [ABSTRACT FROM AUTHOR]

There have been several studies on heavy metals in Lake Naivasha. However, none of them has reported the levels of mercury (Hg), arsenic (As), and chromium (Cr). Moreover, there are no studies on the heavy metals' concentrations in the straightfin barb (Enteromius paludinosus, Peters 1852), a fish species that hosts a parasite (Ligula intestinalis), the latter having been reported to have a high ability to absorb heavy metals from its host. This paper therefore addresses the accumulation of heavy metals, namely arsenic (As), chromium (Cr), lead (Pb), and mercury (Hg) in the tissues of straightfin barb, Enteromius paludinosus (Peters 1852) from the mouth of River Malewa in Lake Naivasha, Kenya. A total of 1307 fish were collected during the month of November 2017. Water samples, sediment samples, 25 fish muscle tissues, and its endoparasite, the cestode Ligula intestinalis, were isolated, and heavy metal concentrations were determined using the thermal-electron atomic absorption spectrophotometer at the Lake Nakuru Water Quality Testing Laboratory. The concentrations of heavy metals in the sediment were below the lowest effect level in sediment, threshold effect concentration in sediment, severe effect concentration in sediment, and the shale values of sedimentary rocks thus showing no sign of pollution. In the muscle tissues of the fish, As, Cr, Pb, and Hg showed high levels with mean concentrations of 5.0696, 22.0854, 45.2108, and 1.5458 mg/kg ww, respectively. Bioconcentration factors further supported the observation that trace element accumulation was higher in fish compared with sediment and water. The target hazard quotients of As, Cr, Pb, and Hg obtained for both the female and male were > 1 indicating a possible health risk associated with the consumption of E. paludinosus. The bioaccumulation factors (BAFs) for L. intestinalis were 2.4093, 2.1873, 5.8601, and 5.1395 for As, Cr, Pb, and Hg, respectively, indicating the potential of the cestode in the accumulation of heavy metals from the host; hence, it can be used as an accumulation bioindicator. [ABSTRACT FROM AUTHOR]

In this study the transfer characteristics of mercury (Hg) from a wide range of Chinese soils to corn grain (cultivar Zhengdan 958) were investigated. Prediction models were developed for determining the Hg bioconcentration factor (BCF) of Zhengdan 958 from soil, including the soil properties, such as pH, organic matter (OM) concentration, cation exchange capacity (CEC), total nitrogen concentration (TN), total phosphorus concentration (TP), total potassium concentration (TK), and total Hg concentration (THg), using multiple stepwise regression analysis. These prediction models were applied to other non-model corn cultivars using a cross-species extrapolation approach. The results indicated that the soil pH was the most important factor associated with the transfer of Hg from soil to corn grain. Hg bioaccumulation in corn grain increased with the decreasing pH. No significant differences were found between two prediction models derived from different rates of Hg applied to the soil as HgCl2. The prediction models established in this study can be applied to other non-model corn cultivars and are useful for predicting Hg bioconcentration in corn grain and assessing the ecological risk of Hg in different soils.

This study investigated the distribution of Pb, Cd, Cr, Fe, Cu and Zn in the whole tissues of oysters (Saccostrea cucullata) and mussels (Perna viridis) collected from the three river basins of the coastal area in Chanthaburi Province, Thailand. The heavy metal concentrations in oysters followed the order: Zn>Fe>Cu>Cd>Cr>Pb, whereas in the mussels it was: Fe>Zn>Cu>Cr>Cd>Pb. The concentrations of Cu and Zn in the oysters were higher than the permission standard, and the bioconcentration factor (BCF) study revealed the ability of the oysters to accumulate the heavy metals. The results of depuration found that Cu and Zn levels in both oysters and mussels were below the permission standard after the end of the process. The time of depuration was related to the levels of Cu and Zn with the higher r values and the relationship of the depuration study obtained from the results of multiple regression analysis.

Nickel (Ni) uptake pattern may be influenced in the presence of lead (Pb) metal ions in the soil and may mediate the Ni dynamics in root and shoot part of spinach. A pot culture experiment was carried out with four levels of each Pb (0, 100, 150, and 300 mg kg−1soil) and Ni (0, 100, 150, and 300 mg kg−1 soil) in spinach to assess the Pb and Ni contamination interactive effect on Ni dynamics in soil. Study revealed that increasing the concentration of Pb and Ni enhanced the concentration of the respective metals in the spinach root and shoot parts. Increasing the levels of Pb (0-300 mg kg−1) had significantly (p = 0.05) reduced the Ni uptake in shoot and root from 0.195 to 0.033 mg pot−1 and from 0.026 to 0.008 mg pot−1, respectively. The metal dynamics ratios, i.e., bioconcentration factor (BCF), translocation factor (TF), transfer efficiency (TE), and crop removal of Ni were also negatively affected by application of Pb. Increasing the Pb levels in soil from 100 to 300 mg kg−1 significantly (p = 0.05) decreases BCF value from 0.113 to 0.108. Under multi-metal toxicity conditions, high level of Pb in the effluent reduced the Ni uptake by spinach and affects the soil health. The findings are very much useful for planning effective effluent management strategies and guidelines to reduce the metal contamination in food crops under peri-urban areas. [ABSTRACT FROM AUTHOR]

The aim of the study was to compare accumulation capacity of selected biogenic and toxic metals (As, Cd, Cu, Pb, Sb, and Zn) in the leaves of 3 tree species (Alnus glutinosa, Salix sp., and Sambucus nigra) from 5 locations in the Malé Karpaty Mountains in the Slovak Republic near Trniansky, Stoličný, and Gidra streams. These observed locations (with accentuation to upper flows of mentioned streams) are characterized by mainly high occurrences of arsenic and antimony as a result of geological bedding and abandoned Sb mining deposits in the Pezinok area. Obtained results confirmed that each tree species in view varied in accumulation capacity for individual metals. While Salix sp. indicated in the leaves high levels of As, Cd, and Zn, Sambucus nigra accumulated from all spotted trees in the highest amounts mainly lead and antimony. The lowest cadmium accumulation was confirmed for Alnus glutinosa. Regression analysis confirmed significantly positive correlations between Pb--Cu (p<0.001), Cd--Cu (p<0.01), and Pb--Cd (p<0.01) concentrations in Alnus glutinosa leaves. However, for Sambucus nigra there was significantly positive correlation confirmed between As--Sb (p < 0.001). [ABSTRACT FROM AUTHOR]

Salvinia minima was assessed for its ability to accumulate lead (Pb) by exposing it to concentrations of 40 µM Pb(NO 3 ) 2 during 24 h. At the same time, the expression levels were quantified, of four genes coding for transporters: SmABCC (ABCC-MRP), SmATPase (ATPase-P3A), SmNhaD (Type-Na + /H + ) and SmABCG (ABCG-WBC). In the absence of lead, S. minima had very low expression of those genes, when plants were exposed to the metal however, those genes showed a rapid (in just three hours or less) and sharp increase (up to 60 times) in their expression, particularly the SmNhaD (Type-Na + /H + ) gene. This sharp increase in expression levels of the genes studied, occurred at the same time that the plant accumulated the highest content of lead in its tissues. The first two genes, are apparently implicated in detoxification and lead accumulation mechanisms, while the other two genes are apparently involved in maintaining cell balance (homeostatic control) and membrane integrity. Our results confirmed that S. minima is efficient for phytoremediation of water bodies contaminated by lead, as it is efficient in accumulating this metal in its tissues (bioconcentration factor; BCF) values greater than 1000, in short times of exposure. More importantly, our data on the expression profiles of four genes coding for transporters, represent a first sight scenario of the molecular basis for understanding the different mechanism of detoxification, apparently present in this aquatic fern. [ABSTRACT FROM AUTHOR]

With the aim to refine water analysis in fish bioconcentration studies, automated solid-phase microextraction (SPME) was used as an alternative approach to conventional solvent extraction (liquid-liquid extraction [LLE]) for the extraction of 3 hydrophobic organic chemicals (HOCs; log KOW 5.5-7.8) from flow-through studies with rainbow trout ( Oncorhynchus mykiss). The results showed that total concentrations extracted by SPME combined with internal standards and LLE are equal. The results further verify the possibility of simultaneous extraction of total and freely dissolved HOC concentrations by SPME. Freely dissolved concentrations allow the assessment of sorption and bioavailability of HOCs in bioconcentration studies and their potential impact on resulting bioconcentration factors (BCFs). Reduction in freely dissolved water concentrations can result in an underestimation of BCFs if they are calculated based on total water concentrations. For polychlorinated biphenyl (PCB) 153, a significant increase in BCF value was observed when freely dissolved concentrations were taken into account. However, log BCF values calculated based on freely dissolved concentrations did not correlate linearly with log KOW values above 5 to 6. This pointed to further influences besides a reduction in freely dissolved water concentrations by sorption to organic matter. The results can aid in assessment of the factors that influence bioconcentration systems and also give important information regarding the possible replacement of LLE by SPME for water analysis of highly HOCs in fish bioconcentration studies. Environ Toxicol Chem 2017;36:2887-2894. © 2017 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The ANTARES dataset is a large collection of known and verified experimental bioconcentration factor data, involving 851 highly heterogeneous compounds from which 159 are pesticides. The BCF ANTARES data were used to derive a conformation-independent QSPR model. A large set of 27,017 molecular descriptors was explored, with the main intention of capturing the most relevant structural characteristics affecting the studied property. The structural descriptors were derived with different freeware tools, such as PaDEL, Epi Suite, CORAL, Mold2, RECON, and QuBiLs-MAS, and so it was interesting to find out the way that the different descriptor tools complemented each other in order to improve the statistical quality of the established QSPR. The best multivariable linear regression models were found with the Replacement Method variable sub-set selection technique. The proposed QSPR model improves previous reported models of the bioconcentration factor in the present dataset. [ABSTRACT FROM PUBLISHER]

The performance of aqueous exposure bioconcentration fish tests according to Organisation for Economic Co-operation and Development (OECD) guideline 305 requires the possibility of preparing stable aqueous concentrations of the test substances. For highly hydrophobic organic chemicals (HOCs; octanol-water partition coefficient [log KOW] > 5), testing via aqueous exposure may become increasingly difficult. A solid-phase desorption dosing system was developed to generate stable concentrations of HOCs without using solubilizing agents. The system was tested with hexachlorobenzene (HCB), o-terphenyl (oTP), polychlorinated biphenyl (PCB) 153, and dibenz[a,h]anthracene (DBA) (log KOW 5.5-7.8) in 2 flow-through fish tests with rainbow trout ( Oncorhynchus mykiss). The analysis of the test media applied during the bioconcentration factor (BCF) studies showed that stable analyte concentrations of the 4 HOCs were maintained in the test system over an uptake period of 8 wk. Bioconcentration factors (L kg−1 wet wt) were estimated for HCB (BCF 35 589), oTP (BCF 12 040), and PCB 153 (BCF 18 539) based on total water concentrations. No bioconcentration could be determined for DBA, probably because of the rapid metabolism of the test item. The solid-phase desorption dosing system is suitable to provide stable aqueous concentrations of HOCs required to determine the bioconcentration in fish and represents a viable alternative to the use of solubilizing agents for the preparation of test solutions. Environ Toxicol Chem 2017;36:906-916. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC. [ABSTRACT FROM AUTHOR]