Metal accumulation and rhizosphere microbial associations in Nymphaea lotus and Limnocharis flava from a natural wetland

Migration patterns and pollution assessment of heavy metals in seawater, sediments, and marine organisms in the Xisha coral reef ecosystem of the South China Sea.

Heavy metal accumulations in tropical seaweed and seagrass species as the basis of an ecological risk assessment.

Ionizable organic compounds (IOCs) represent an important class of environmental chemicals. Though zebrafish embryos are increasingly utilized as alternative vertebrate models in chemical hazard and risk assessment related to human health and the environment, it remains unclear whether life-stage-specific physiology alters toxicokinetics and bioconcentration potential of IOCs. Here, we examined toxicokinetics and bioconcentration factors (BCFs) of eight ionizable pharmaceuticals with diverse physicochemical properties using a mixture exposure design across embryonic and larval stages of zebrafish. Coexposure did not markedly alter toxicokinetic parameters for the IOCs relative to single exposure at similar concentrations. We observed development-dependent and ionization-state-specific toxicokinetic processes and accumulation in zebrafish. Larvae exhibited an enhanced uptake and reduced elimination for cationic compounds. Importantly, the BCF values of cationic amitriptyline and cisapride exceeded the regulatory bioaccumulation threshold in larvae. Conversely, most anionic compounds displayed lower uptake and elimination in larvae, yielding similar BCFs across the stages. Further, we identified higher bioaccumulation for cations than anions in larvae, and IOC bioconcentration was generally elevated in larvae compared with embryos, which is increasingly employed in basic and translational environmental and biomedical studies. These findings highlight the importance of considering life stage and ionization state when using zebrafish as alternative models in risk assessment.

Per- and polyfluoroalkyl substances (PFAS) is persistent global contaminant. As regulations on legacy compounds like perfluorooctanoic acid (PFOA) tighten, hexafluoropropylene oxide trimer acid (HFPO-TA) and dimer acid (HFPO-DA) have emerged as primary alternatives. This study comprehensively evaluated the acute toxicity, tissue bioconcentration, and oxidative stress mechanisms of these two emerging alternatives using the Oryzias melastigma as a model organism. Acute toxicity assays demonstrated that HFPO-TA is significantly more lethal than HFPO-DA. The 96-hr median lethal concentration (96-hr LC50) for HFPO-TA (130 mg/L) was lower than HFPO-DA (2700 mg/L). The predicted no-effect concentration (PNEC) for HFPO-TA and HFPO-DA was 0.13 and 2.7 mg/L, respectively. During the 21-day chronic exposure, both compounds accumulated in visceral tissue and followed a power function growth model relative to exposure concentrations. The bioconcentration factor (BCF) of HFPO-TA was 3.3-33, higher than that of HFPO-DA (0.5-4.2). Both compounds show a decreasing trend with increasing concentration. HFPO-TA exhibited significantly higher bioaccumulation potentials and tissue burdens compared to HFPO-DA at similar exposure levels, indicating superior bioavailability. Regarding toxic mechanisms, both pollutants disrupted the homeostasis of the antioxidant defense system. The responses of key biomarkers, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH), consistently followed a dynamic "inhibition-compensation-decompensation" trajectory. Specifically, initial enzyme inhibition at low concentration was followed by a compensatory recovery at moderate concentration, which eventually failed at high concentrations, leading to decompensatory decline and oxidative damage. These findings indicate that HFPO-TA poses a greater ecological threat than HFPO-DA. Consequently, HFPO-TA is likely not a viable substitute for PFOA and the ecological risks of these fluorinated alternatives require urgent re-evaluation.

Yunnan is a major coffee region in China. This study explores mineral sources and bioavailability to identify geochemical indicators for origin traceability. We analyzed 85 soil, 52 coffee beans, and 4 bedrock samples from Pu'er and Baoshan, Yunnan. Eleven elements (Cr, Cu, Mn, Zn, Ca, K, Mg, Fe, Pb, Mo, As) were measured by coupled plasma mass spectrometry, along with soil pH and organic matter. Enrichment factors, bioconcentration factors, principal component analysis, and partial least squares regression were applied to assess elemental mobility, sources, and traceability. K, Ca, Mg, Cu, and Mo showed high bioavailability with greater uptake in Pu'er. Lead, As, Mn, Zn, Fe, and Cu accumulated more in Pu'er beans, while Cr was enriched in Baoshan. Chromium, Mo, and As derived from human activities, whereas Mg, Ca, and K from weathering rock. Elemental sources in Pu'er involved weathering, industry, and agriculture; in Baoshan, coal combustion, mining, and agriculture dominated. Three latent variables were extracted, with higher explanatory power in Pu'er (Xp = 78.07%, Yp = 38.69%) than Baoshan (Xb = 46.26%, Yb = 29.49%). The LV1 axis clearly distinguished origins, identifying Cr, Cu, Ca, and Mg as key soil indicators for coffee traceability. All toxic elements were below safety limits. Pu'er showed higher Pb and As accumulation, while Baoshan had more Zn and Mn. Natural weathering mainly contributed to Mg, Ca, and K; human activities influenced Cr, Mo, and As. Partial least squares regression effectively distinguished origins, highlighting Cr, Cu, Ca, and Mg as effective markers for distinguishing coffee origins.

The aim of studying the phyto-accumulation of F− by Vallisneria spiralis L. in a hydroponic treatment is to investigate its potential for the phytoremediation technique of F− contaminated water. In each container, we treated three selected mature plants that measured 15–20 cm in root and 30–40 cm in shoot length. This research aims to understand the plant’s ability to absorb, tolerate, and sequester F− from the water bodies, offering a low-cost, sustainable, and eco-friendly process for water purification. A comprehensive methodology was adopted, including Taguchi experimental design, monitoring of plant parameters, chemical analysis of F− content, morphological and biochemical characterization, and statistical optimization. The study found that after 20 days of treatment, the plant showed its highest absorption efficiency when exposed to a 10 mg/L fluoride solution, with root biomass accumulating 1.20 mg/g dry weight and shoot biomass absorbing 0.98 mg/g dry weight. SEM-EDX and FTIR were used to characterize the interaction between F− ions and extract materials of plant root biomass. The treated plants show maximum values of bio-concentration factor and translocation factor for F− were found to be 1.111 and 1.116. This suggests the plant holds potential for use in phytoremediation techniques to extract F− from aquatic environments.

Bioconcentration kinetics and underlying mechanisms of tire additives and their transformation products in the fry stage of rainbow trout (Oncorhynchus mykiss).

Long-term mining has exacerbated heavy metal contamination in regional soils, leading to their accumulation in crops and posing significant health risks to local populations. This study applied an integrated evaluation framework combining field sampling, conventional multi-index methods, and the Influence Index of Comprehensive Quality (IICQ) to assess heavy metal contamination in a mining-affected agroecosystem. Results indicated that 26.4% of soils were contaminated, dominated by Cd, Zn, and Pb, primarily near mining sites. In maize, 55.4% of samples were polluted, mainly due to As and Ni, with 30.4% and 55.4% exceeding their respective safety limits. Low bioconcentration factors and weak soil-crop correlations revealed a contamination disconnect. Critically, theIICQidentified 26.8% of soil-maize systems as "sub-healthy", highlighting the limitation of relying solely on soil data for predicting crop safety. Health risk assessment based on maize consumption revealed distinct and population-specific dietary risks. For children, the non-carcinogenic hazard index (HI) reached 1.31, exceeding the safe threshold of 1, which was driven largely by arsenic neurotoxicity. For adults, although the non-carcinogenic risk was below the threshold (HI = 0.58), the total carcinogenic risk (TCR) was 1.67 × 10⁻4, surpassing the USEPA's acceptable limit (10⁻4). This study demonstrates the applicability of the IICQ as an innovative framework for comprehensively assessing heavy metal contamination status in mining-affected soil-crop systems and informing region-specific risk management.

A tiered secondary poisoning risk assessment approach to prevent unnecessary fish bioaccumulation testing of pharmaceuticals.

Integrative assessment of cadmium stress adaptation in Ocimum spp.: Linking biochemical defense, anatomical plasticity, and essential oil biosynthesis.

Increasing salinity exacerbates the bioaccumulation and toxicity of perfluorooctanoic acid (PFOA) in Manila clams (Ruditapes philippinarum).

BackgroundWild plant species serve as significant models for evaluating the effects of anthropogenic activities on terrestrial ecosystems. In recent years, phytoremediation has garnered significant attention as a sustainable approach to remediate metal-contaminated soils, due to its ability to maintain soil structure while facilitating potential metal recovery. This study assessed the phytoremediation capabilities of seven indigenous wild plant species in soils impacted by phosphate mining operations.MethodsMetal concentrations in soil and plant samples were measured by atomic spectroscopy. Ten biologically distinct rhizosphere soil samples were collected for each of the seven wild plant species; each biological replicate was made up of pooled material from five individual plants. The effectiveness of phytoremediation was evaluated by computing the Biological Accumulation Coefficient (BAC), Bioaccumulation Factor (BF), Element Accumulation Index (EAI), and Translocation Factor (TF) for selected trace metals.Results and discussionMetal bioavailability was significantly associated with soil pH and organic matter content. The concentration of soil macronutrients was low. The bioconcentration factor exceeded one for most tested elements. Mn and Zn in Bidens pilosa and Conyza bonariensis were the sole exceptions. All metals except Mn had biological accumulation coefficients greater than 1. TF values suggested variable translocation potential among the studied plant species.ConclusionThe results indicate that the examined native plant species can tolerate elevated metal concentrations and sequester them, thereby endorsing their potential application in the remediation of phosphate-mining-affected metal-contaminated soils.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12870-026-08832-z.

Microplastics reduce pyrene bioaccumulation and trophic transfer in brine shrimp-marine medaka food chain: the role of sorption versus biotransformation.

Heavy metals are among the most critical pollutants affecting aquatic ecosystems due to their persistence, toxicity, and bioaccumulation potential. Lake Manzala, the largest coastal lake in Egypt, is increasingly exposed to contamination from agricultural, industrial, and domestic discharges. This study evaluated the potential of Pontederia crassipes (water hyacinth) as a bioindicator and phytoremediator of heavy metals in three locations of Lake Manzala. Concentrations of iron (Fe), zinc (Zn), copper (Cu), lead (Pb), nickel (Ni), and cadmium (Cd) were determined in water and plant tissues using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Bioaccumulation was assessed using the Biological Accumulation Coefficient (BAC), Bioconcentration Factor (BF), and Translocation Factor (TF). The results showed that metal concentrations in water followed the order: Fe > Zn > Cu > Pb > Ni > Cd, with significantly higher levels (p < 0.05) recorded at the northeastern site. P. crassipes accumulated all metals predominantly in roots, with significantly higher concentrations than in leaves (p < 0.05). BF values exceeded 1 for all metals, indicating strong accumulation capacity, while TF values remained below 1, suggesting limited translocation to aerial parts. Significant positive correlations (p < 0.05) were observed between metal concentrations in water and plant tissues. These findings demonstrate that P. crassipes is an effective bioindicator and phytostabilizer of heavy metals in freshwater ecosystems. The study highlights its potential application in environmental monitoring and sustainable phytoremediation strategies for polluted aquatic ecosystems such as Lake Manzala.

High cadmium accumulation by common coltsfoot (Tussilago farfara L.), herbal plant growing and collecting in ruderal habitats.

This study investigates the role of rhizospheric bacteria in enhancing the phytoremediation capacity of Parthenium hysterophorus growing on distillery sludge, aiming at the ecorestoration of polluted environments. Physicochemical analysis revealed notable reductions in pollutants, with salts decreasing to 15.74–53.79 mg/kg and metals reduced by 28.69–80.26 mg/kg. GC–MS profiling of fresh and 50-day-old plant tissues indicated bioconversion and disappearance of several distillery-derived organic pollutants, underscoring the plant’s ability to degrade and transform contaminants. Metal analysis showed bioaccumulation in roots, shoots, and leaves, with bioconcentration factors (BCF > 1) for Fe, Zn, Cu, Ni, Pb, and Cr, and translocation factors (TF > 1) for Fe, Zn, Mn, Ni, and Pb, confirming strong phytoextraction potential. Furthermore, phytostabilization of Cu and Cr was observed. Transmission electron microscopy of roots revealed dense metal deposits in the cytoplasm, along with structural adaptations such as multi-vacuoles, mitochondria, and chloroplasts, indicating high tolerance to metal stress. The rhizospheric bacterial community, dominated by Alcaligenes faecalis, Cytobacillus firmus, Bacillus subtilis, and Niallia circulans, exhibited plant growth-promoting traits that support remediation. Overall, the findings highlight P. hysterophorus as an effective candidate for phytoremediation and bacterial-assisted eco-restoration of industrially contaminated sites.

This study investigates the occurrence and transfer of potentially toxic metals in roadside and agricultural soils, Pennisetum glaucum fodder, and cow milk across areas with varying traffic density in Kallar Kahar, Pakistan. Samples were digested using a wet acid digestion method and analyzed using Atomic Absorption Spectrometry (AAS) under strict quality control protocols. The analyzed milk samples exhibited a broad range of metal concentrations, with Zn ranging from 1.99 to 3.16mg/L, Fe from 0.16 to 0.32mg/L, Mn from 0.02 to 0.28mg/L, Cu from 0.001 to 0.008mg/L, Pb from 0.001 to 0.009mg/L, Cd from 0.0001 to 0.009mg/L, Co from 0.0002 to 0.008mg/L, and Mo from 0.001 to 0.004mg/L. Contamination Factor (CF), Bioconcentration Factor (BCF), Daily Intake of Metal (DIM), and Health Risk Index (HRI) computations suggested that all values are below 1, indicating low levels of contamination and no immediate health risk under the studied conditions. However, values approaching threshold limits (e.g., Cd in milk and Mo in soil) suggest the need for cautious interpretation and long-term monitoring. Comparative analysis with international guidelines confirmed that metal levels in the study area are within safe limits. These findings highlight the suitability of the local environment for fodder production and dairy farming while emphasizing the importance of continuous monitoring to mitigate potential long-term risks.

Soil contamination by zinc (Zn) derived from landfill leachate poses significant ecological risks, particularly in regions with limited waste management capacity such as Indonesia. The Jatibarang landfill in Semarang has reported soil Zn concentrations exceeding the Ecological Soil Screening Level, highlighting the need for sustainable remediation strategies. This studyevaluated the stability of vetiver (Chrysopogon zizanioides)-based phytoremediation under varying plant densities and compost amendment in leachate-contaminated soil. A two-month greenhouse experiment was conducted using a 2 × 2 factorial completely randomised design with two planting densities (one and three plants per polybag) and two compost treatments (with and without compost). Parameters observed included soil Zn concentration, removal efficiency, bioconcentration factor (BCF), translocation factor (TF), plant biomass, and soil pH, analysed using two-way ANOVA (? = 0.05). All treatments significantly reduced soil Zn concentrations from 174.41 mg/kg to 49.33-52.17 mg/kg, corresponding to removal efficiencies of 70.09-71.72%, with no statistically significant differences among treatment combinations. Zinc accumulation occurred predominantly in the roots, reflected by higher root BCF values and TF values generally below one, confirming phytostabilisation as the dominant remediation mechanism. These findings indicate that vetiver-based phytoremediation provides a stable and reliable strategy for controlling Zn mobility in landfill leachate-contaminated soils, supporting its application as a sustainable soil management approach.

ABSTRACT Purpose This study assessed the accumulation of heavy metals (Pb, Cd, Cu, Zn, Cr, Fe, and Ni) in six halophytic species and evaluated their phytoremediation potential. Additionally, remote sensing indices, including NDVI (Normalized Difference Vegetation Index), SAVI (Soil Adjusted Vegetation Index), NDSI (Normalized Difference Salinity Index), and land surface temperature, were used to analyze soil salinity patterns and vegetation distribution. Materials and methods Polluted saline soils and plant samples were collected from ten sites along Egypt’s Mediterranean coast. Heavy metals were determined after acid digestion, and bioconcentration (BCF) and translocation (TF) factors were calculated. Remote sensing data were used to assess vegetation health and environmental stress. Results Showed significant spatial variability in salinity and metal concentrations, with the highest salinity recorded at Site 3. Mesembryanthemum cordifolium accumulated high levels of Cu, Fe, Ni, and Cr in shoots, while Suaeda vermiculata showed high Cd and Zn accumulation in roots. Bassia indica roots contained the highest Pb levels. Most BCF values were below 1, except for Cd and Zn in S. vermiculata, while TF values generally exceeded 1. Soil alkalinity likely reduced the mobility of some metals. Conclusion These findings highlight the role of halophytes as bioindicators and their potential in phytoremediation, supporting their use in sustainable restoration of saline, contaminated ecosystems.