Bioconcentration Research Articles

Effect of various phosphorus levels on the extraction of Cd, the transformation of P, and phosphorus-related gene during the phytoremediation of Cd contaminated soil

Phytoremediation has emerged as a common technique for remediating Cd pollution in farmland soil. Moreover, phosphorus, an essential element for plants, can alter the pectin content of plant cell walls and facilitate the accumulation of Cd in plant tissues, thereby enhancing phytoremediation efficiency. Therefore, pot experiments were conducted in order to investigate the effect of phosphorus levels on Cd extraction, phosphorus transformation and phosphorus-related genes during phytoremediation. The results revealed that an optimal application of suitable phosphate fertilizers elevated the soil's pH and electrical conductivity (EC), facilitated the conversion of soil from insoluble phosphorus into available forms, augmented the release of pertinent enzyme activity, and induced the expression of phosphorus cycling-related genes. These enhancements in soil conditions significantly promoted the growth of ryegrass. When applying phosphorus at a rate of 600 mg/kg, ryegrass exhibited plant height, dry weight, and chlorophyll relative content that were 1.27, 1.26, and 1.18 times higher than those in the control group (P0), while the Cd content was 1.12 times greater than that of P0. The potentially toxic elements decline ratio and bioconcentration factor were 42.86% and 1.17 times higher than those of P0, respectively. Consequently, ryegrass demonstrated the highest Cd removal efficiency under these conditions. Results from redundancy analysis (RDA) revealed a significant correlation among pH, total phosphorus, heavy metal content, phosphorus forms, soil enzyme activity, and phosphorus-related genes. In conclusion, this study suggests applying an optimal amount of suitable phosphate fertilizers can enhance restoration efficiency, leading to a reduction in soil Cd content and ultimately improving the safety of crop production in farmlands.

Investigating the correlation between pesticide bioconcentration and human disease through the integration of remote sensing and physical modeling

ABSTRACT 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 R 2 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.

Inventing hyperaccumulator plants: improving practice in phytoextraction research and terminology

Toxic metals and metalloids, especially from anthropogenic sources, now pollute substantial areas of our planet. Phytoextraction is a proven technology with the potential to reduce metal/metalloid pollution, and where financially viable, recover valuable metals (‘phytomining’). Toward these aims, there has been a surge of publications over the last two decades. While important progress is being made, ongoing propagation of poor practice, and the resultant drain from funding sources, is hindering this promising research area. This includes mis-ascribing hyperaccumulator species, hydroponics with extremely high dose levels, misuse of Bioconcentration Factors, use of food or biomass crops with low accumulation for phytoextraction, the phenomenon of ‘template papers’ in which a known hyperaccumulator for element X is dosed with element Y, or a common weed species dosed with any variety of elements to make it ‘hyperaccumulate’. Here we highlight these misconceptions with the hope that this will help to: (i) disseminate accurate definitions for in planta metal accumulation; (ii) quash the propagation of poor practice by limiting the inflation of unnecessary publications via the practice of ‘template paper’ writing; (iii) be used by journal editors and reviewers to validate their reasoning to authors; and (iv) contribute to faster progress in delivering this technology to in-the-field practitioners.

Prediction of the biodegradation of chemicals using OECD QSAR Toolbox software

Introduction. The development of integrated approaches to testing, assessment of the hazard and exposure risk of chemicals on human health and the environment is one of the priorities of preventive toxicology. An integrated approach involves various combinations of methods in silico, in chemico, in vitro, ex vivo, in vivo for hazard assessment. In the Russian Federation, in silico methods are often perceived with skepticism, mainly due to the lack of their legal status, weak methodological base and insufficient training of specialists. In order to expand the methodological base, the possibility of predicting the stability of chemicals in biotic conditions using the OECD QSAR Toolbox software was studied.
 Material and methods. The OECD QSAR Toolbox software version 4.4.1., OECD guidelines on the assessment of biodegradation of chemicals.
 Results. The world community and the OECD have developed and implemented a three-level system for chemicals biodegradation testing, which includes tests for readily biodegradation (OECD Guidelines 301 A, 301 B, 301 C, 301 D, 301 E, 301 F, 306, 310), tests to determine the potential biodegradability (OECD Guidelines 302 A, 302 B, 302 C, 304 A) and model systems tests (OECD Guidelines 303 A, 303 B).
 To test the capabilities of the program, 24 endpoints were selected. They are the determination of biodegradability (%) by BOD, DOC, CO2, CH4 releases in OECD tests 301 A, 301 B, 301 C, 301 D, 
 302 C, 302 B, biodegradability (%) in sediments and soil, bioconcentration factors for more than 100 organic chemicals of various structures.
 The parameters were calculated using the analog method, followed by mandatory interpretation of the data obtained by an expert. When predicting the biodegradability of chemicals, it is necessary to perform a series of calculations using different tests (OECD tests 301 A, 301 B, 301 C, 301 D, 301 E, 302 B are preferred) and grouping methods followed by a comprehensive assessment of the results obtained, taking into account not only the structural similarity of substances and analogues, but also the quality of the experimental data used. When predicting biodegradability by BOD values, it is advisable to use the OECD 301 C test. The proportion of tested substances whose biodegradability could be estimated by BOD values is about 50% in the OECD 301 C test, which is primarily due to the presence of a significant amount of experimental data. The calculation of bioconcentration factors seems to be promising. For about 45% of the tested substances, it was possible to calculate bioconcentration coefficients with good correlation with experimental data. Biodegradation in soil (% and half-life) can be predicted only for a very limited range of compounds (10% of the tested substances), which is due to the difficulty of selecting structurally similar analogues with experimental data. The method is not applicable for predicting the biodegradation of salts, organometallic compounds, polymer molecules and mixed products.
 Conclusion. The Russian Register of Potentially Hazardous Chemical and Biological Substances has developed a methodological guide for predicting the stability of chemicals in biotic conditions using the OECD QSAR Toolbox software. The document presents algorithms for calculating biodegradability (%) according to OECD tests 301, 302, 303; BOD, bioconcentration factors and biodegradability (%) in soil.

Uptake, tissue distribution, and biotransformation pattern of triclosan in tilapia exposed to environmentally-relevant concentrations

Although triclosan has been ubiquitously detected in aquatic environment and is known to have various adverse effects to fish, details on its uptake, bioconcentration, and elimination in fish tissues are still limited. This study investigated the uptake and elimination toxicokinetics, bioconcentration, and biotransformation potential of triclosan in Nile tilapia (Oreochromis niloticus) exposed to environmentally-relevant concentrations under semi-static regimes for 7 days. For toxicokinetics, triclosan reached a plateau concentration within 5-days of exposure, and decreased to stable concentration within 5 days of elimination. Approximately 50 % of triclosan was excreted by fish through feces, and up to 29 % of triclosan was excreted through the biliary excretion. For fish exposed to 200 ng·L−1, 2000 ng·L−1, and 20,000 ng·L−1, the bioconcentration factors (log BCFs) of triclosan in fish tissues obeyed similar order: bile ≈ intestine > gonad ≈ stomach > liver > kidney ≈ gill > skin ≈ plasma > brain > muscle. The log BCFs of triclosan in fish tissues are approximately maintained constants, no matter what triclosan concentrations in exposure water. Seven biotransformation products of triclosan, involved in both phase I and phase II metabolism, were identified in this study, which were produced through hydroxylation, bond cleavages, dichlorination, and sulfation pathways. Metabolite of triclosan-O-sulfate was detected in all tissues of tilapia, and more toxic product of 2,4-dichlorophenol was also found in intestine, gonad, and bile of tilapia. Meanwhile, two metabolites of 2,4-dichlorophenol-O-sulfate and monohydroxy-triclosan-O-sulfate were firstly discovered in the skin, liver, gill, intestine, gonad, and bile of tilapia in this study. These findings highlight the importance of considering triclosan biotransformation products in ecological assessment. They also provide a scientific basis for health risk evaluation of triclosan to humans, who are associated with dietary exposure through ingesting fish.

Antimicrobials in Eisenia fetida earthworms: A comprehensive study from method development to the assessment of uptake and degradation

In this work, an accurate analytical method was developed for the simultaneous analysis of twenty-seven antimicrobials (AMs) in earthworms using liquid chromatography coupled to a triple quadrupole mass spectrometry detector (UHPLC-MS/MS). Adequate apparent recoveries (80–120 %) and limits of quantification (LOQ) (1 μg·kg−1 - 10 μg·kg−1) were obtained, with the exception of norfloxacin (34 μg·kg−1). The method was applied to evaluate the accumulation of sulfamethazine (SMZ) and tetracycline (TC) in earthworms after performing OECD-207 toxicity test, in which Eisenia fetida (E. fetida) organisms were exposed to soils spiked with 10 mg·kg−1, 100 mg·kg−1 or 1000 mg·kg−1 of SMZ and TC, individually. The results confirmed the bioaccumulation of both AMs in the organisms, showing a greater tendency to accumulate SMZ since higher bioconcentration factor values were obtained for this compound at the exposure concentrations tested. In addition, the degradation of both AMs in both matrices, soils and earthworms was studied using liquid chromatography coupled to a q-Orbitrap high resolution mass spectrometry detector. Thirteen transformation products (TPs) were successfully identified, eight of them being identified for the first time in soil/earthworm (such as 4-Amino-3-chloro-n-(4,6-dimethylpyrimidin-2-yl)benzenesulfonamide or 4-(dimethylamino)-1,11,12a-trihydroxy-6,6-dimethyl-3,7,10,12-tetraoxo-3,4,4a,5,5a,6,7,10,12,12a-decahydrotetracene-2-carboxamide, among others) and their formation/degradation trend over time was also studied. Regarding the biological effects, only SMZ caused changes in earthworm growth, evidenced by weight loss in earthworms exposed to concentrations of 100 mg·kg−1 and 1000 mg·kg−1. Riboflavin decreased at all concentrations of SMZ, as well as at the highest concentration of TC. This indicates that these antibiotics can potentially alter the immune system of E. fetida. This research represents a significant advance in improving our knowledge about the contamination of soil by AM over time. It investigates the various ways in which earthworms are exposed to AMs, either by skin contact or ingestion. Furthermore, it explores how these substances accumulate in earthworms, the processes by which earthworms break them down or metabolise them, as well as the resulting TPs. Finally, it examines the potential effects of these substances on the environment.

Exogenous strigolactone improves the cadmium accumulation in Solanum nigrum var. humile

AbstractThe effects of exogenous strigolactone (using strigolactone analog GR24) on the cadmium (Cd) accumulation in Solanum nigrum var. humile were studied by a pot experiment. The Cd treatment (0.1 mg/L) inhibited the growth of S. nigrum var. humile, indicating that 0.1 mg/L produced the stress to S. nigrum var. humile. Spraying GR24 at 1 μmol/L did not change plant dry biomass, increased the photosynthetic pigment content and catalase activity, and decreased the peroxidase activity under Cd stress. By contrast, spraying GR24 at 2 μmol/L had no significant effects on these parameters. The superoxide dismutase activity was decreased by GR24 at 1 μmol/L, but increased by GR24 at 2 μmol/L. Nevertheless, both GR24 at 1 and 2 μmol/L increased the Cd contents, bioconcentration factors, and Cd extractions in various plant organs. Compared to Cd treatment, GR24 at 1 and 2 μmol/L increased the shoot Cd extraction by 20.0% and 14.5%, respectively. So, application of exogenous strigolactone could improve the phytoremediation capacity of S. nigrum var. humile. Correlation and grey relational analyses showed that the root Cd content, shoot Cd content, and root Cd extraction were the top three parameters closely related to the shoot Cd extraction. These findings suggest that exogenous strigolactone can effectively promote the Cd accumulation in S. nigrum var. humile, presenting a promising solution to enhance its phytoremediation capacity.

NH4+-N and Low Ratios of NH4+-N/NO3−-N Promote the Remediation Efficiency of Salix linearistipularis in Cd- and Pb-Contaminated Soil

(1) Background: the utilization of fast-growing trees for phytoremediation in heavy-metal-contaminated soil is increasingly recognized as an effective remediation method. Nitrogen (N) fertilizer enhances plant tolerance to heavy metals, yet the impact of various N levels and ammonium (NH4+-N)/nitrate (NO3−-N) ratios on the remediation of cadmium (Cd) and lead (Pb) by trees remains unclear. (2) Methods: the efficiency of Salix linearistipularis in remediating Cd- and Pb-contaminated soil was investigated using a pot experiment with three N levels (60, 120, 200 kg hm−1 year−1) and five NH4+-N/NO3−-N ratios (6/0, 4/2, 3/3, 2/4, 0/6) employed, resulting in 16 treatments including a control. (3) Results: the levels and ratios of NH4+-N/NO3−-N significantly affected the Cd and Pb uptake by S. linearistipularis. The highest increases in Cd and Pb in S. linearistipularis were observed for the N120-6/0 treatment, which increased by 104.36% and 95.23%, respectively. In addition, in the N120-6/0 treatment, the stem and leaf bioconcentration factors of Cd were significantly enhanced by 28.66% and 40.11%, respectively. Structural equation modeling revealed that the uptake of Cd and Pb was predominantly influenced by plant traits (biomass and root traits) rather than soil properties. (4) Conclusions: Our findings highlight the potential of the NH4+-N/NO3−-N ratio to regulate plant traits, thereby improving the phytoremediation efficiency of heavy-metal-contaminated soil.

Evaluating capability of two halophyte plants for phytoextraction of cadmium from contaminated soils

Selecting an appropriate plant is a key factor for the phytoextraction of heavy metals from contaminated soils. The possibility of using two halophytes for the remediation of cadmium (Cd) from contaminated soils was investigated. Consequently, an experiment with Chenopodium album L. and Chenopodium botrys L. including Cd treatments of 0, 5,10, 20, 40, 60, 80 and 100 ppm was conducted. Designated analyses including fresh weight, dry weight, and Cd concentrations in shoots and roots were performed. Results indicated that for both plants, a logarithmic model performed best to demonstrate the relationship between total soil Cd with shoot Cd and dry matter. Although both halophytes had considerable capability to remediate Cd from soils, C. botrys demonstrated greater potential to accumulate Cd in shoots. The range of bioconcentration factor (BCF) in C. botrys was obtained to be 0.8 to 8.8 and in C. album was 0.4 to 1.73. For C album, BCF in most treatments was lower than 1.0, but for C. botrys, it was mostly larger than 1.0. Although both plants can be used as hyperaccumulators to remediate Cd-polluted soils, the clean-up time of C. album under higher Cd concentrations was shorter than C. botrys L.

Nano-scale and micron-scale plastics amplify the bioaccumulation of benzophenone-3 and ciprofloxacin, as well as their co-exposure effect on disturbing the antioxidant defense system in mussels, Perna viridis

Plastics ranging from nano-scale to micron-scale are frequently ingested by many marine animals. These particles exhibit biotoxicity and additionally perform as vectors that convey and amass adsorbed chemicals within organisms. Meanwhile, the frequency of detection of the benzophenone-3 and ciprofloxacin can be adsorbed on plastic particles, then accumulated in bivalves, causing biotoxicity. To understand their unknown accumulative kinetics in vivo affected by different plastic sizes and toxic effect from co-exposure, several scenarios were set up in which the mode organism were exposed to 0.6 mg/L of polystyrene carrying benzophenone-3 and ciprofloxacin in three sizes (300 nm, 38 μm, and 0.6 mm). The live Asian green mussels were chosen as mode organism for exposure experiments, in which they were exposed to environments with plastics of different sizes laden with benzophenone-3 and ciprofloxacin, then depurated for 7 days. The bioaccumulation and depuration kinetics of benzophenone-3 and ciprofloxacin were measured using HPLC-MS/MS after one week of exposure and depuration. Meanwhile, their toxic effect were investigated by measuring the changes in six biomarkers (condition index, reactive oxygen species, catalase, glutathione, lipid peroxidation, cytochrome P450 and DNA damage). The bioconcentration factors in mussels under different exposure conditions were 41.48–111.75 for benzophenone-3 and 6.45 to 12.35 for ciprofloxacin. The results suggested that microplastics and nanoplastics can act as carriers to increase bioaccumulation and toxicity of adsorbates in mussels in a size-dependent manner. Overproduction of reactive oxygen species caused by microplastics and nanoplastics led to increased DNA damage, lipid peroxidation, and changes in antioxidant enzymes and non-enzymatic antioxidants during exposure. Marked disruption of antioxidant defenses and genotoxic effects in mussels during depuration indicated impaired recovery. Compared to micron-scale plastic with sizes over a hundred micrometers that had little effect on bivalve bioaccumulation and toxicity, nano-scale plastic greatly enhanced the biotoxicity effect.

Phytoremediation of heavy metal and tetracycline co‐contaminated soil by Solanum nigrum L.: Response of tetracycline‐resistant genes

AbstractCo‐contamination with heavy metals (HMs) and tetracyclines (TCs) in soils has been widely reported and has resulted in serious consequences, such as the diffusion of tetracycline‐resistant genes (TRGs). Phytoremediation displays high potential for the remediation of co‐contaminated soils. Here, we chose a Cd hyperaccumulator (Solanum nigrum L.) to explore the accumulation of HMs in plants and the effect of TRG diffusion in HM‐TC‐contaminated soil by conducting a pot experiment. The results showed that the shoot biomass of S. nigrum L. decreased by 28.39%–73.00% in treatments with HM (Cd and Cu) contamination singly caused by the toxicity of a nontarget element (Cu). The Cd concentrations in S. nigrum L. shoots increased by 30 times, while the Cu concentrations increased by less than 3 times. The bioconcentration factors (BCFs) and translocation factors (TFs) of Cd ranged from 1.05 to 7.98 and 0.80 to 2.27, respectively, which decreased with increasing TC concentrations in most treatments. The TC residuals in soils increased greatly with increasing TC and HM concentrations. Their concentrations in S. nigrum L. tissues followed the order chlorotetracycline > tetracycline > oxytetracycline. Phytoremediation stimulated the growth of soil microorganisms and increased the abundance of mobile genetic elements (intI 1) and TRGs, especially efflux pump genes (tet C and tet G, which increased 2.97 and 4.13 logs after phytoremediation, respectively). Our results suggested that phytoremediation had a high potential for HM and TC removal; however, it increased the diffusion risk of TRGs, especially for efflux pump genes that functioned in both HM and TC resistance.

Personal care products: an emerging threat to the marine bivalve Ruditapes philippinarum

In the last few decades, there has been a growing interest in understanding the behavior of personal care products (PCPs) in the aquatic environment. In this regard, the aim of this study is to estimate the accumulation and effects of four PCPs within the clam Ruditapes philippinarum. The PCPs selected were triclosan, OTNE, benzophenone-3, and octocrylene. A progressive uptake was observed and maximum concentrations in tissues were reached at the end of the exposure phase, up to levels of 0.68 µg g−1, 24 µg g−1, 0.81 µg g−1, and 1.52 µg g−1 for OTNE, BP-3, OC, and TCS, respectively. After the PCP post-exposure period, the removal percentages were higher than 65%. The estimated logarithm bioconcentration factor ranged from 3.34 to 2.93, in concordance with the lipophobicity of each substance. No lethal effects were found although significant changes were observed for ethoxyresorufin O-demethylase activity, glutathione S-transferase activity, lipid peroxidation, and DNA damage.

Mechanism of composite passivators to reduce cadmium absorption and accumulation in Chinese cabbage on cadmium-polluted soil

Abstract Background The accumulation of heavy metals, including cadmium (Cd), in soil endangers the quality of agricultural products and can harm human health. At present, the application of passivators is a relatively efficient, quick, and economical way to address this problem. In the experimental site of the present study, the effects of different composite passivators (red mud + lime + phosphorite powder, red mud + lime + biochar, lime + humic acid + seafoam, seafoam + biochar + red mud, seafoam + biochar + phosphorite powder) on the physiology and biochemistry of Chinese cabbage were investigated. Results After passivator application, the soil’s effective state Cd content was reduced, and the Cd content, bioconcentration factor (BCF), transfer coefficient (TF), oxidative stress, and antioxidant enzyme activity levels of Chinese cabbage leaves and stalks were reduced to different degrees. The reduction of reactive oxygen species content was mainly owing to passivator application, which reduced the degree of oxidative stress and increased the content of osmotic substances, the activity of antioxidant enzymes, and the ability to scavenge hydroxyl radicals. The soluble protein content of Chinese cabbage was mainly increased by an increase in the content of osmotic substances and non-enzymatic antioxidant substances and a reduction in the inhibition of protein synthesis. Conclusions Our findings suggest that the reduction of reactive oxygen species was the main cause of the reduction of Cd accumulation, transport, and toxicity in leaves. The increase in soluble protein was the main cause of the reduction of Cd accumulation, transport, and toxicity in petioles. Graphical Abstract

Accumulation and Phytotoxicity of Cypermethrin and Deltamethrin to Aquatic Plants

Synthetic pyrethroid contamination in water is a serious environmental concern as this pesticide is highly toxic to aquatic animals. Phytoremediation using aquatic plants that can tolerate and accumulate pyrethroid pesticides is an interesting alternative. In this study, the phytotoxicity of cypermethrin and deltamethrin, alone or in combination, to three aquatic plants, Azolla microphylla, Salvinia cucullate, and Spirodela polyrrhiza were tested. The results show that S. cucullate was the most sensitive species because the pigment content in the fronds significantly decreased when exposed to pyrethroid in water. Azolla microphylla was the most tolerant species because the pigment content in their fronds significantly increased when exposed to pyrethroid and cypermethrin, which could also significantly increase the plant fresh weight of A. microphylla. Both species could accumulate synthetic pyrethroid pesticides in their tissue. The bioconcentration factors of cypermethrin and deltamethrin in A. microphylla were 3,508.8 and 2,323.5, respectively, while the bioconcentration factors of cypermethrin and deltamethrin in S. cucullate were 453.0 and 381.7, respectively. Azolla microphylla is appropriate for use in pyrethroid phytoremediation in water.

Trace element translocation patterns in the epigeous parts of 15 common Canadian urban plant species grown in a contaminated soil

Green initiatives and phytotechnologies, such as phytoremediation, hold great potential for the sustainable management of contaminated brownfields. One impediment to these initiatives is the lack of alternatives for the produced biomass due to the potential contamination of plants by trace elements. We conducted an experiment to quantify the accumulation and the translocation patterns of trace elements in the aboveground parts of fifteen desirable plants species used for these kinds of initiatives, i.e. urban predominance, ecological relevance, edibility, commercial prospective, and phytoremediation potential. The experiment was set-up in a tunnel-type greenhouse in which plants were grown in pots filled with contaminated urban soil containing Cu, Zn, Se, Ag and spiked with Cd. Our results indicated that different species exhibited differential abilities to accumulate and translocate trace elements in their aboveground biomass and furthermore, exhibited different bioconcentration factors. A clear exclusion of Cd allocation was observed in fruits and flowers. However, Cd content in edible parts was still above the standard recommendations for human consumption. Our results suggest potential candidates for phytoremediation by revealing different accumulation patterns, also highlighting the importance of characterizing trace elements in the soil for selecting the appropriate plant species based on project’s needs.

Phytoextraction potential of Canna indica (L.) for Cd removal from a hydroponic system

ABSTRACT The research explored Canna indica's ability to extract Cd in hydroponic conditions, determining its upper tolerance threshold and assessing Cd's impact on growth and biochemical properties. Plants were grown in 5L tanks containing nutrient solutions with varying Cd concentrations (0, 100, 200, 300, and 400 mg/L) for 18 days. Each treatment was performed in triplicate. Analysis of Cd content across roots, shoot, and leaves revealed high absorption rates of 89.5% to 96.8% efficiency for Cd treatments of 100–400 mg/L. Metrics like bioaccumulation coefficient (BAC), translocation factor (TF), and bio-concentration factor (BCF) were determined, indicating BAC > 1 across treatments, while TF was <1 for 100 mg/L and >1 for higher Cd treatments. Bio-concentration patterns varied with Cd concentration. Optimal Cd uptake occurred at 200–300 mg/L, declining notably at 400 mg/L. The study suggests C. indica's potential for phytoextraction up to 400 mg/L Cd contamination, but adverse effects emerged at ≥300 mg/L: reduced chlorophyll pigments, ascorbic acid, fresh/dry weights, and elevated leaf pH, indicating a Cd tolerance threshold of 300 mg/L for C. indica.

Integrated approaches for heavy metal-contaminated soil remediation: harnessing the potential of Paulownia elongata S. Y. Hu, Oscillatoria sp., arbuscular mycorrhizal fungi (Glomus mosseae and Glomus intraradices), and iron nanoparticles.

In recent years, researchers have extensively investigated the remediation of heavy metal-contaminated soil using plants, microorganisms, and iron nanoparticles. The objective of this study was to investigate and compare the individual and simultaneous effects of Paulownia elongata S. Y. Hu, cyanobacteria (Oscillatoria sp.), arbuscular mycorrhizal fungi (AMF) including Glomus mosseae and Glomus intraradices, and zero-valent iron nanoparticles (nZVI) on the remediation of heavy metal-contaminated soil containing chromium (Cr VI and Cr III) and nickel (Ni). The study found significant variations in parameters such as pH (acidity), electrical conductivity (EC), nitrogen (N), phosphorus (P), potassium (K), and organic carbon (OC) among different treatments. The addition of cyanobacteria, AMF, and nZVI influenced these properties, resulting in both increases and decreases compared to the control treatment. The treatment involving a combination of cyanobacteria, AMF, and nZVI (CCAN25) exhibited the highest increase in growth parameters, such as total dry mass, root length, stem diameter, and leaf area, while other treatments showed varied effects on plant growth. Moreover, the CCAN25 treatment demonstrated the highest increase in chlorophyll a, chlorophyll b, and carotenoid levels, whereas other treatments displayed reductions in these pigments compared to the control. Moderate phytoaccumulation of Cr and Ni in P. elongata samples across all treatments was observed, as indicated by the bioconcentration factor and bioaccumulation coefficient values being less than 1.0 for both metals. The findings provide insights into the potential application of these treatments for soil remediation and plant growth enhancement in contaminated environments.

Glyphosate- and aminomethylphosphonic acid (AMPA)-induced mortality and residues in juvenile brown trout (Salmo trutta f. fario) exposed at different temperatures

BackgroundGlyphosate is a broad-spectrum, non-selective systemic herbicide with a commonly assumed low potential for accumulation in biota. Nevertheless, glyphosate has been shown to bioaccumulate in the tissues of several organisms. To understand the bioconcentration dynamics of glyphosate in fish, brown trout (Salmo trutta forma fario) of different age were exposed to different concentrations of glyphosate, the formulation Roundup® LB Plus, and the major transformation product aminomethylphosphonic acid (AMPA) for two, three, or four weeks at different temperatures in the laboratory. Mortality rates were determined, and tissue samples were collected at the end of the experiment to ascertain concentrations of glyphosate and AMPA residues by liquid chromatography coupled to mass spectrometry (LC–MS/MS).ResultsBrown trout mortality during exposure to glyphosate or AMPA was considerably higher at 15 °C than at 7 °C. Also, a significant increase in glyphosate concentrations in samples containing muscle, head, backbone, and caudal fin tissue with increasing exposure concentrations and temperatures was observed. Six-month-old fish contained more glyphosate per kg wet weight after exposure than ten-month-old fish. The bioconcentration factors (BCFs) for glyphosate and AMPA were much higher at 15 °C than at 7 °C, but in both cases decreased with higher glyphosate concentrations. The BCF for glyphosate formulated in Roundup® was higher than the one for the parent compound. Approximately 30–42% of the organ-absorbed glyphosate and AMPA remained in the tissues even when the fish were kept in clean water lacking the test substances for three weeks after termination of exposure.ConclusionOur study demonstrated that there is an interaction between glyphosate and ambient temperature in terms of toxicity. Further it was shown that increasing concentrations of glyphosate and AMPA in the surrounding media lead to significantly increased concentrations of these substances in brown trout tissues, although neither bioconcentration nor bioaccumulation of glyphosate in animal tissues is expected due to the high water solubility of this chemical. As a consequence, the uptake of glyphosate by humans through the consumption of contaminated edible fish is very likely.

Influence of Biochar on Plant Uptake of Personal Care Products: Caffeine and Triclosan

The use of personal care products (PCPs) extends a person's longevity. Nonetheless, because of its uncontrolled burden on the environment, it is regarded as an emerging contaminant. The goal of this research is to determine the influence of cinnamon wood biochar (CWBC) on plant uptake of caffeine (CFN) and triclosan (TRI) from the soil. Ipomeoa aquatica was cultivated for 4 weeks in soil with a 2.5% CWBC amendment and spiked with 100 mg/kg CFN and 200 mg/kg TRI. Ultra- High-performance liquid chromatography (UHPLC) was used to quantify the CFN and TRI in the plant. The surface morphology of CWBC was investigated by scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) surface area. The gasification of biomass which increased the CWBC's surface area to 589 m2/g, due to the development of a porous structure. The CFN accumulated more in the shoot of the plant whereas TRI accumulated in the root. The addition of 2.5% CWBC significantly (p&lt;0.05) decreased the root and shoot accumulation of CFN by 40.4% and 70.9%, whilst those for TRI by 38.9% and 19.9%, respectively. The relative bioconcentration factors (RBF) of CFN and TRI in shoot and root was calculated by the ratio of bioconcentration factor (BCF) using RBF=〖BCF(CWBC amended soil)⁄〖BCF_soil and the results suggested that the addition of 2.5% CWBC decrease the RBF below the one indicating the effectiveness of CWBC towards mitigating the plant uptake of PCPs. Overall, the present study suggested the application of biochar to soil significantly decreased the plant uptake of PCPs, thus, can reduce the potential risk caused by the unintentional consumption of contaminated vegetables. &#x0D; Keywords: Personal Care Products, Soil amendment, Health risk, Plant uptake

Comparative study of heavy metal content of &lt;i&gt;Manihot esculenta&lt;/i&gt; tubers and soil in Rivers State, Nigeria: Effect on histology of kidney and liver of Wistar rats

There is a concern that Manihot esculenta Crantz (Euphorbiaceae) grown in Rivers State, Nigeria may be contaminated with heavy metals due to industrial activities with likely risk to human health. This study determined the heavy metal contents in the soil and tubers of M. esculenta and potential health risks in Wistar rats. Tubers harvested from different farms in Rumuji, Omoku and Gokhana areas of the state with their corresponding soil samples were combined and analyzed for heavy metals such as Pb, Cd, Hg, Cr, As and Ni. The control group rats received normal feed while test groups were fed with 30g of blended tubers from the locations respectively for 28 days. The liver and the kidneys were harvested for histopathological examination. Nickel, Pb, and Cr were present in the three locations while Cd and As were not found in Rumuji and Omoku but were present in Gokhana with a concentration of (0.01 ± 0.00 and 0.01±0.00 mg/kg) respectively. Bioconcentration factor was &gt;1 for Pb and Cr in Rumuji. Liver histopathology showed fatty degeneration while the kidney tissues exhibited occluded Bowman’s capsule space. Heavy metals concentrations were within permissible limits although histological findings indicated some degree of hepatotoxicity and nephrotoxicity.