Bioconcentration Factor Values Research Articles

Assessment of trace element occurrence in Nile Tilapia from the Rosetta branch of the River Nile, Egypt: Implications for human health risk via lifetime consumption

River pollution can harm human health through direct contact, drinking water, and the consumption of contaminated fish and irrigated agricultural products. Surface water and Nile tilapia (Oreochromis niloticus) samples were collected monthly from July 2022 to June 2023 at three sites (El-Rahawy, Sabal, and Tala) along the Rosetta Nile branch in Egypt to monitor the presence of eight trace elements. The potential human health risks from consuming contaminated fish were also assessed. Iron and manganese were consistently detected in all water samples across most seasons and locations, with concentrations generally below the WHO permissible levels. All 72 analyzed fish muscle samples were found to contain trace elements. The mean concentrations of metals in the fish muscle samples, in descending order, were: iron > zinc > copper > manganese > tin > antimony > lead > mercury. Significant spatial and seasonal variations were observed in both water and fish samples. El-Rahawy was identified as the most contaminated site, with summer exhibiting the highest contamination rate compared to other seasons. Fish samples collected from El-Rahawy demonstrated the highest bioconcentration factor (BCF) values for most elements, particularly mercury, lead, iron, manganese, and antimony. Target hazard quotient (THQ) calculations for the trace elements in Nile tilapia muscles revealed that all trace elements, except antimony, had THQ values below 1, suggesting that consuming Nile tilapia from these sites is unlikely to cause adverse health effects. However, THQ values for antimony exceeded the threshold of 1, indicating a potential health risk for consumers. Although the detected trace elements in the fish were below the permissible toxicity limits, some could pose a future threat to human health, necessitating further studies, ongoing monitoring, and preventive measures.

ACCUMULATION OF HEAVY METALS IN APPLES AND PEARS FROM THE SUBURBS OF MITROVICA, KOSOVO

Intake of heavy metals through the food is a food safety problem that seriously affects consumer health. Therefore, information is needed on the intake of food contaminated with heavy metals and their concentrations, to assess the potential risk for human health. This paper aims to determine the accumulation of metals in apples and pears grown in the surroundings of Kosovska Mitrovica (Republic of Kosovo) and the bioconcentration factor (BF). With the help of the ICP-MS technique, were determined the amounts of Cu, Fe, Co, Mn, Ni, and Cr in apples and pears grown in three regions - Zvečan , Frashër, and Polski. From the conducted tests, the highest concentrations in apples and pears were determined for iron (on average 100.67 mg/kg for apples and 107.4 mg/kg for pears) and the lowest concentrations for cobalt (on average 0.13 mg/kg for apples and 0.18 mg/kg for pears). The lowest bioconcentration factor in apples is 0.01 (for Fe, Co, and Mn in all three regions), and the highest is 0.32 (for Cr in Zvečan). When determining the bioconcentration factor in pears, the lowest (0.01) was determined for iron (in all three regions) and manganese (in Zvečan and Frashër regions), and the highest bioconcentration factor was determined for copper – 0.46 (Polski region). There is a very high correlation between the values obtained for the analyzed metals in apples and pears. According to BF values, pears extract twice as much Cu and Co from the soil compared to apples, and the extraction of other metals from the soil is the same for both types of fruit.

Micronutrient and heavy metal bioaccumulation in Bermuda grass (Cynodon dactylon L. Pers) grown in calcareous soil using stabilized and dried sewage sludge

This study examines the micronutrients and heavy metal bioaccumulation in Bermuda grass (Cynodon dactylon L. Pers), grown in two different types of calcareous soil (CS) with the application of stabilized and dried sewage sludge (SS). At the end of the growth period, the Fe, Zn, Mn and Cu (micronutrients) concentrations in the substrate have increased. Furthermore, it was determined that the total Fe, Zn, Mn and Cu concentrations were higher in CS1 compared to CS2. For the heavy metals the concentrations of Ni and Cr have increased, and the concentration of total Cd has slightly but significantly decreased. The total Pb concentration was below the detection limit (DL for Pb <0.03 mg kg-1). It was determined that the total Ni, Cr and Cd concentrations were higher in CS1 than in CS2. In the aerial biomass of the Bermuda grass, the Fe and Zn concentrations have increased with increasing SS applications, whereas Mn concentrations have decreased. Ni, Cr, Cd and Pb concentrations were unaffected by SS applications for both types of CS. The bioconcentration factor (BCF) values for the shoot of the plant (BCFFe, BCFZn, BCFMn, BCFCu, BCFNi, BCFCr, BCFCd) were determined to be below the critical limit of 1. The application of sewage sludge has not resulted in bioaccumulation above critical limits in the shoot of the plant. However, considering Bermuda grass substrate, it can be suggested to add sewage sludge to the calcareous soil in amounts between 20–40 t ha-1, considering its long-term remanence.

The Potential of Helichsryum splendidum (Thunb.) Less. for the Restoration of Sites Polluted with Coal Fly Ash.

The disposal of coal fly ash (CFA) generated from coal-fired power stations has serious impact on the ecosystem, by converting large pieces of land to barren ash dams with the potential to contaminate groundwater, surface water, air and soil. The aim of this study was to clarify the potential of phytoremediation using Helichrysum splendidum (Thunb.) Less. in areas polluted by CFA through conduction of pot trial experiments for 14 weeks. Plants of the same age were cultivated in CFA to assess their growth, photosynthetic rate and tolerance towards metal toxicity. This study revealed that the CFA was moderately polluted with heavy metals, and a lower photosynthetic rate was recorded for the CFA plants in comparison to the controls (plants grown in soil). Although the CO2 assimilation rate was lower for the CFA plants, increased growth was recorded for all the plants tested. Inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify the amount of trace elements in samples and parameters including translocation factor (TF) and bioconcentration factor (BCF) were used to evaluate the phytoremediation potential of H. splendidum (Thunb.) Less. The results revealed that higher concentrations of Cd, Co, Cr, Cu, Mn and Pb were accumulated in the roots, while As, Ni and Zn were found in the shoots. Elements including As, Cr and Zn reported TF values above 1, indicating the plants' phytoextraction potential. The BCF values for As, Cu and Zn were 1.22, 1.19 and 1.03, indicating effectiveness in the phytostabilization processes. A removal rate efficiency ranging from 18.0 to 56.7% was recorded confirming that, H. splendidum (Thunb.) Less. can be employed for restoration of CFA dams.

Machine learning-based q-RASAR predictions of the bioconcentration factor of organic molecules estimated following the organisation for economic co-operation and development guideline 305

In this study, we utilized an innovative quantitative read-across (RA) structure-activity relationship (q-RASAR) approach to predict the bioconcentration factor (BCF) values of a diverse range of organic compounds, based on a dataset of 575 compounds tested using Organisation for Economic Co-operation and Development Test Guideline 305 for bioaccumulation in fish. Initially, we constructed the q-RASAR model using the partial least squares regression method, yielding promising statistical results for the training set (R2 =0.71, Q2LOO=0.68, mean absolute error [MAE]training=0.54). The model was further validated using the test set (Q2F1=0.77, Q2F2=0.75, MAEtest=0.51). Subsequently, we explored the q-RASAR method using other regression-based supervised machine-learning algorithms, demonstrating favourable results for the training and test sets. All models exhibited R2 and Q2F1 values exceeding 0.7, Q2LOO values greater than 0.6, and low MAE values, indicating high model quality and predictive capability for new, unidentified chemical substances. These findings represent the significance of the RASAR method in enhancing predictivity for new unknown chemicals due to the incorporation of similarity functions in the RASAR descriptors, independent of a specific algorithm.

The Potential of Talisay-Dagat (Terminalia catappa L.) for Phytoremediation in Langihan Lagoon, Butuan City, Agusan del Norte, Philippines

The study aims to determine the potential of Talisay-dagat (Terminalia catappa L.) for phytoremediation and to examine its influence on reducing concentrations of heavy metals in the soil of Langihan Lagoon, Butuan City. Soil, roots, and leaves were collected and brought to the Regional Soils Laboratory using microwave-assisted aqua-regia digestion and determination through Inductively Coupled Plasma Optical Emission Spectrometer. The study made use of mathematical computations such as translocation factor (TF), bioconcentration factor (BCF), and enrichment factor (EF) to determine whether the tree is a hyperaccumulator, excluder, or indicator. In the TF results, T. catappa was a hyperaccumulator for Ni and Cu, considering that the concentration exceeds one (1) while demonstrating as a possible excluder for Cr. There was also an emphasis on limited absorption of heavy metals, as evidenced by the BCF and EF value of less than 1. The results show that based on TF, BCF, and EF values, only TF shows the effectivity of restricting the root-shoot ratio translocation of Ni and Cu (TF > 1). Regression analysis found that the absorption of T. catappa was not influenced by the amount of heavy metal in the soil within the studied condition. This insight was crucial in understanding the plant’s absorption and could guide further research or practical applications in environmental management and phytoremediation. Keywords: bioconcentration factor, hyperaccumulator, phytoremediation, Terminalia catappa, translocation factor

Synchrotron induced X-ray fluorescence spectroscopy reveals heavy metal translocation in sludge amended soil-plant systems: assessment of ecological and health risks.

The use of composted sludge from sewage treatment plants as a soil amendment is a common practice of recycling nutrients like organic carbon, nitrogen, and phosphorus. The sewage generated in larger cities of developing countries is often contaminated with various heavy metals (HMs) that ultimately end up in composted sludge. Thus, using such composted sludge is likely to pose ecological and human health risks. Hence, the knowledge of HM translocation in sludge-soil-plant systems is of vital importance. The present study was aimed at investigating the HM translocation in sludge-soil-plant system. The HM translocation was measured using synchrotron radiation-induced x-ray fluorescence spectrometry and atomic absorption spectroscopic techniques. The results indicated high HM mobility (up to 2628.5mgkg-1) from sludge to spinach plant. The metal accumulation (mgkg-1) ranged in the order-Fe (950.55-2628.5) > Zn (20.11-172.13) > Cu (13.86-136.17) > Mn (2.13-34.67) > Cd (0.11-31.17) > Pb (1.50-30.16) > Co (0.18-9.85) As (0.02-7.80) > Cr (0.01-5.69). This observed accumulation depended on the volume of sewage being treated in the sewage treatment plant (STP) and varied in the order control < (8 MLD Bhagwanpur, STP 1) < (80 MLD Dinapur, STP2) < (140 MLD Dinapur, STP3) hence the HM load coming into STPs. The metal transfer factor, bioconcentration factor, and translocation factor values also correlated with the abundance of Fe, Cu, Pb, Cd, and Zn in spinach root and shoot compartments. The carcinogenic risk for heavy metal carcinogens like As, Cd, Cr, and Pb revealed children being more prone to cancer upon spinach consumption. Hence, it is necessary to assess the heavy metals present in the sludge prior to its application in agricultural fields.

Occurrence, distribution, and correlation of antibiotics in the aquatic ecosystem of Poyang Lake Basin, China

The widespread existence and persistence of antibiotics in the aquatic environment, and their extensive ecological risks, have attracted considerable attention. The objective of this study was to evaluate the occurrence and distribution of 25 antibiotics in environmental and biological samples from Poyang Lake Basin in China. SPE–HPLC–MS/MS was used to quantify the concentrations in different matrices. The total concentrations ranged from 144 to 933 ng/L in the water and 346 to 1154 ng/g in the sediment. In the spatial distribution analysis of this basin, the concentrations in the Ganjiang River were generally higher than those in Poyang Lake. The seasonal distribution in the wet and dry seasons showed comparatively higher concentrations during the dry season than the wet season. Additionally, antibiotics were found in various hydrophytes and animals, and the bioconcentration factor values followed the order: emergent plants > floating plants > submerged plants and benthic organisms > ducks > fish. Moreover, correlations among different matrices showed that antibiotics in viviparid snails were significantly positively correlated with those in ducks, and negatively correlated with those in carps, indicating the transmission relationship through the food chain. The results showed the trophic transfer of antibiotics in the food web and their potential environmental impacts on Poyang Lake Basin need constant attention.

Characteristics of Soil Selenium-cadmium Migration and Accumulation and Its Bioeffectiveness in Typical Geological High Background Area

The prevalence of selenium-cadmium （Se-Cd） symbiosis in soils of geologically high background areas directly affects the safe utilization of Se-rich land resources. To investigate the migration and accumulation characteristics and bio-effectiveness of Se-Cd in the soil-crop system in typical geological high background areas of Southwest China and to realize the safe use of natural Se-rich land resources in geological high background areas, we collected 84 samples of agricultural crops （maize） and their supporting root systems and analyzed the Se-Cd content and physicochemical properties. Se-Cd accumulation characteristics, influencing factors, and bio-effectiveness of the soil-crop system were evaluated using geostatistics, bioenrichment factors, and geographic detectors. The results showed that the Se-Cd content in the study area was significantly higher than the background value of the soil in the whole country and in Yunnan Province. Influenced by the geological background, secondary enrichment in the process of soil formation, and agricultural activities, the accumulation and enrichment characteristics of Se in the root soil varied from no enrichment to slightly enriched, and the occurrence form was dominated by the residue state. The accumulation index of soil Cd was mainly in the medium pollution level, and the occurrence form was mainly in the residual state and the combined state of iron and manganese. The Se-enrichment rate of crop seeds reached 98.8% （DB 50/T 524-2013 standard）, and the average value of bioconcentration factor was 5.8%. The exceeding rate of Cd content in crop seeds was only 1.19% （GB 2762-2022 standard）, and the average value of Cd bioconcentration factor was 2.11%, so the ecological risk of heavy metal Cd in crop seeds was relatively low. In the Se-Cd symbiosis area under geological background, the weak alkaline environment of the soil could effectively reduce the bioavailability of Cd in crop seeds, and the Se-rich soil could inhibit the uptake of Cd by the crops to a certain extent. Correlation analysis showed that the migration and accumulation of Se and Cd from soil to crop seeds in the soil-crop system were affected by the elemental accumulation pattern and the physical and chemical properties （pH） of the soil, and at the same time, there was a certain synergistic-antagonistic effect between Se and Cd in the soil-crop system. Correlation analysis showed that the migration and accumulation of Se and Cd from soil to crop seeds in the soil-crop system was influenced by the occurrence of elements, soil physicochemical properties （pH）, and other factors, and there was also a certain synergistic-antagonistic interaction between Se and Cd in the soil-crop system.

Evaluating phytoremediation potential and nutrients status of Bassia indica (Wight) A. J. Scott (Indian Bassia) in a cadmium-contaminated saline soil.

Bassia indica (Wight) A. J. Scott is a fast-growing halophyte suitable for the remediation of saline lands on a large scale. However, no information is available regarding its phytoremediation potential for cadmium (Cd) alone or in combination with salinity. Besides evaluating phytoremediation, assessing micronutrient hemostasis as a crucial physiological insight into the mechanism involved in the tolerance of B. indica under saline soil contaminated with Cd was subjected. Under salinity stress, a considerable amount of sodium accumulates in the plant. Moreover, the accumulation of sodium increased by Cd stress levels. The increase in the exchangeable form of Cd in the rhizosphere in the presence of NaCl ions further elevated the Cd content in the plant tissues. For instance, compared to non-saline conditions, applying 2.5 and 5 g NaCl kg-1 to soil treated with 60 mg Cd kg-1 increased exchangeable Cd by 28.4 and 49.5% in rhizosphere soil, which led to increased cadmium content by 16.1 and 29.6% in the root (as amainpart of Cd accumulation), respectively. Under most stress conditions, potassium homeostasis in the shoot remained undisturbed. It was observed that this plant could transfer an optimal level of potassium from the roots to the shoots at a moderate salinity level. Changes and the distribution of Cu and Zn levels followed a similar pattern in the plant, indicating a common regulation mechanism for these nutrients. Generally, the plant could maintain an appropriate level of Fe, Zn, and Cu ions under most stressed conditions. However, the level of Mn decreased significantly under severe stress levels. Growth parameters, tolerance index, and the values of translocation factor < 1 and shoot bioconcentration factor > 1 under 5 mg Cd kg-1 soil treatment at different salinity levels indicated that B. indica could mitigate the detrimental effect of Cd toxicity and tolerate the NaCl stress via a phytostabilizer mechanism. However, the shoot bioconcentration factor values were very close to one at other Cd levels. Therefore, considering the obtained evidence and the innate ability of B. indica to remediation salinity, this plant is still recommended, even for higher Cd levels (even until 30 mg kg-1), in the presence of salinity.

Phytoremediation Potentiality of Bottle Gourd Plant (Lagenaria siceraria)

A pot experiment of bottle gourd plant with Pb, Zn, NPK and Vermicompost (VC) was carried out at the Department of Soil, Water and Environment, University of Dhaka. The aim of the study was to introduce a phytoremedial technique. The bottle gourd (Lagenaria siceraria) plant was used in the trial for evaluating its potentiality to accumulate Pb and Zn from soil and translocate these elements to different parts of the plant. Twelve treatments (T) were utilized in the experiment including control (T1). The remaining treatment groups were composed of different ratios of VC and recommended dose of NPK- with and without lead and Zinc. Tolerance to metal stress by the bottle gourd plant was evident in terms of higher biomass and yield production with the Pb and Zn. The maximum total biomass (leaf + stem + root) of fresh (67.49 g) and dry yield (8.41g) was achieved with Pb addition to T11. Bioconcentration factor (BCF) and Translocation Factor (TF) greater than one (BCF&gt;1 and TF&gt;1) were considered indicators of heavy metal accumulators and translocators, respectively. Among the Pb treatments, highest BCF achieved in leaf (1.67) with T12, in stem (1.82) with T8, in root (4.67) with T11 and maximum TF (2.87) found with T11. The Zn treatments exerted the highest BCF value in leaf (1.80), and in stem (1.64) with T10, in root (2.70) with T12, lowest value of BCF and TF were displayed in control (T1). Research exposed that bottle gourd plants had transferred both the heavy metals from soil significantly. The highest Pb accumulation in leaf was found to be 0.0023% (dry weight) in T10 and the lowest (0%) in T1. The highest translocation factor was found in T5 for Pb and in T11 for Zn. Moreover, bioconcentration factor (Pb) in shoots exhibited a significant, strong, and negative correlation (r = -0.804, p = 0.002) with the soil organic carbon content. There was also a strong, significantly negative correlation between total Pb content in soil and BCF (leaf) (r = -0.717, p = 0.009), as well as BCF (stem) (r = -0.692, p = 0.013). Similar relationship was found in case of Zn. The study revealed that bottle gourd plants possess phytoremedial potentiality which will be beneficial for the pollution context of Bangladesh. Further investigation is needed for greater research interest. Biodivers. Conserv. Bioresour. Manag. 2024, 10(1): 59-74

Influencing Factors and Prediction Models of Mercury Phytoavailability and Transference in a Soil–Lettuce System under Chinese Agricultural Soils

Mercury (Hg) is a highly toxic contaminant posing serious ecological and human health risks. This study investigates the Hg transfer characteristics and prediction models in a soil–lettuce system, employing bioconcentration factors (BCF), path analysis (PA), and Freundlich-type functions. A pot experiment was conducted in a greenhouse, where lettuce was grown in a range of Chinese agricultural soils (n = 21) and deliberately spiked with Hg using Hg(NO3)2 solution. The results indicated that lettuce grown in Hg-spiked acidic soils (pH &lt; 6.5) accumulated total Hg (THg) levels up to 14.01 µg kg−1, surpassing the safe consumption limit of 10 µg kg−1. The BCF for lettuce THg was less than 1.0, suggesting a low transfer of Hg from soil to lettuce. Notably, BCF values were significantly higher in acidic soils (0.02) compared to alkaline soils (0.005). Path analysis accounted for 82% of the variation in lettuce THg content, identifying soil THg, pH, and amorphous (Amo) Al and Fe oxides as primary direct factors. Additionally, soil-available Hg (AvHg), exchangeable Hg (ExHg), clay, and organic matter (OM) were significant indirect factors affecting lettuce THg content. To validate the findings of the path analysis, an extended Freundlich-type equation was developed using stepwise multiple linear regression (SMLR). This model exhibited high predictive accuracy (R2 = 0.82, p ≤ 0.001), with soil pH, THg, and amorphous Al and Fe oxides being the key variables for predicting Hg transfer in the soil–lettuce system. The insights from this study can guide the management of safe lettuce production in Hg-contaminated soils, ensuring the mitigation of Hg exposure through agricultural produce.

Quantifying heavy metal and radionuclide contamination in fish and water proximal to a uranium tailings facility: A Linshui River basin investigation, China

BackgroundThe objective of this study is to evaluate the concentrations of heavy metals and radionuclides in water and fish samples collected from six designated sampling stations along the Linshui River, in close proximity to a Uranium Tailing Pond situated in China. Additionally, it seeks to estimate the bioaccumulation of heavy metals and conduct risk assessments, both carcinogenic and non-carcinogenic, for consumers. MethodsWater and fish samples (yellowhead catfish and common carp) were systematically collected from six stations along the river from January to June 2023, adhering to ethical standards and standard protocols for assessing water quality. Samples underwent chemical preparation and analysis for heavy metals using Graphite Furnace Atomic Absorption Spectrophotometry and Cold Vapor Atomic Absorption Spectroscopy, and for radionuclides using gamma spectrometry, with all methods validated for accuracy. ResultsThe water samples showed metal and radionuclide concentrations within acceptable limits, except for higher levels of U and Th compared to background values. Heavy metal concentrations were higher in common carp compared to yellowhead catfish, with both species exhibiting a similar trend. While non-carcinogenic health risk, as indicated by target hazard quotients, was low for consumers, the health risk data emphasized the carcinogenic threats posed by U238 and Th234. ConclusionsThe study highlights the importance of implementing comprehensive river restoration measures. Additionally, the bioconcentration factor values indicate minimal accumulation of heavy metals in the muscle tissue of fish.

Are Ecological Risk Indices for Trace Metals Relevant for Characterizing Polluted Substrates in the Katangese Copperbelt (DR Congo) and for Assessment of the Performance of Remediation Trials?

This study aims to contribute to the characterization of Katangese Copperbelt’s (DR Congo) mining wastes and soils polluted with trace metals, using pollution indices and direct concentration measurements. This study also evaluated the use of these indices in assessing the success of remediation projects. Data from previous studies and samples collected from six types of discharge and one polluted soil were used to address the first objective. Soil and plant samples were collected at Kipushi and Penga Penga for the second objective. The results reveal very high concentrations of As, Cd, Co, Cu, Mn, Pb, and Zn in all mine tailings and polluted soils, compared with local references. The degree of contamination (DC) values (from 72 to 5440) and potential ecological risk (RI) values (from 549 to 162,091) indicate very high-risk situations associated with polluted discharges and soils. Regarding revegetation trials, the results show lower concentrations and RIs in tree rhizospheres compared with unamended areas at both sites. However, trace metal concentrations are higher in tree rhizospheres compared with local references, and RI values are in the considerable risk range for Penga Penga (RI = 533) and in the very high range (&gt;1500) for Kipushi. Bioconcentration factor values are below 1, indicating low accumulation in roots, wood, and leaves, and low risk of contamination of the trophic chain. In this context, it seems that the pollution indices used are suitable for characterizing pollution and prioritization for remediation. However, their seems unsuitable for assessing the effectiveness of phytotechnology processes based on metal stabilization. Direct plant performance measurements combined with direct measurements of metals in substrates and plants to assess transfer and efficiency are more appropriate.

Interrelation between environmental conditions, acanthocephalan infection and metal(loid) accumulation in fish intestine: an in-depth study

Metal(loid) bioaccumulation in acanthocephalans (Dentitruncus truttae) and intestines of fish (Salmo trutta) from the Krka River, influenced by industrial and municipal wastewaters, was investigated in relation to exposure to metal(loid)s from fish gut content (GC), water, and sediment to estimate potentially available metal (loid)s responsible for toxic effects and cellular disturbances in biota. Sampling was performed in two seasons (spring and autumn) at the reference site (river source, KRS), downstream of the wastewater outlets (Town of Knin, KRK), and in the national park (KNP). Metal(loid) concentrations were measured by ICP-MS. The highest accumulation of As, Ba, Ca, Cu, Fe, Pb, Se and Zn was observed mainly in organisms from KRK, of Cd, Cs, Rb and Tl at KRS, and of Hg, Mn, Mo, Sr and V at KNP. Acanthocephalans showed significantly higher bioaccumulation than fish intestine, especially of toxic metals (Pb, Cd and Tl). Metal(loid) bioaccumulation in organisms partially coincided to exposure from water, sediments and food, while in GC almost all elements were elevated at KNP, reflecting the metal(loid) exposure from sediments. Seasonal differences in organisms and GC indicated higher metal (loid) accumulation in spring, which follows enhanced fish feeding rates. Higher number of acanthocephalans in the intestine influenced biodilution process and lower concentrations of metal(loid)s in fish, indicating positive effects of parasites to their host, as supported by high values of bioconcentration factors. Fish intestine and acanthocephalan D. truttae were confirmed as sensitive indicators of available metal fraction in conditions of generally low environmental exposure in karst ecosystem. Since metal(loid) accumulation depended on ecological, chemical and biological conditions, but also on the dietary habits, physiology of organisms and parasite infection, continuous monitoring is recommended to distinguish between the effects of these factors and environmental exposure when assessing dietary associated metal(loid) exposure in aquatic organisms.

Understanding the spread of antibiotic resistance in vegetables cultivated with sewage sludge: implications for food safety and human health

The conventional practice of using sewage treatment plant (STP) derived sludge as a fertilizer poses significant negative impacts on agroecosystems. Since sludge has diverse contaminants, including heavy metals (HMs), antibiotics (ABs) and antibiotic resistance genes (ARGs), its application in the agricultural fields contaminates the food and hence causes human health risks via the food chain. The transfer of ABs and ARGs from sludge to soil and then to plants can influence the development of antibiotic resistance (AR) in plant endophytes, and leads to variations in their characteristics. In a pot experiment, vegetable carrot (Daucus carota) and spinach (Spinacia oleracea) were amended with sludge samples from three sewage treatment plants (STPs) with varying treatment capacities and both above and below-ground parts of the plants were analysed for the presence of specific ABs (amoxicillin, azithromycin, chloramphenicol, ciprofloxacin, tetracycline), ARGs (blaCTX-M, blaGES, blaNDM, ermF, qnrS, Sul1), and mobile genetic elements (MGEs) (intl1, IS26). Among the characterized culturable endophytic bacteria (EB), 22 exhibited resistance to various antibiotics (highest against ampicillin, ciprofloxacin, chloramphenicol) and heavy metals (highest against lead, nickel, and chromium). Most importantly, seven multiple antibiotic-resistant endophytic bacteria (MAREB) exhibited resistance to all tested heavy metals (HMs). Additionally, all MAREB tested positive for biofilm production, and a notable proportion (72.72%) of these endophytes displayed mobility, with strong auto-aggregation ranging from 16.67 to 92.61%. The biofilm formation dynamics among these MAREB exhibited a Gaussian distribution pattern, increasing with higher antibiotic concentrations. Notably, five MAREB demonstrated survival at clarithromycin concentrations up to 150 µg ml−1. The study revealed the presence of ABs (µg kg−1) and ARGs (copies kg−1) in all parts of both vegetables, ranging from 2.87 to 314.88 and 1 × 105 to 3.2 × 1010, respectively. MAREB displayed various advantageous features to support plant growth under different stress conditions. Moreover, 51.09% of the identified EBs were reported as both plant and human-associated pathogens, and 9.09% were solely human pathogens. Transfer factor (TF), translocation factor (TLF), and bioconcentration factor (BCF) values were correlated with higher ABs and ARGs abundance in the root and shoot compartments of both vegetables. The risk assessment for ABs and ARGs highlighted children are particularly vulnerable to prolonged adverse health risks from consuming these vegetables. Therefore, this research is imperative for understanding the co-selection mechanisms, the need for improvement of the existing treatment systems in contaminants removal, and the evaluation of the presence of ABs and ARGs in sludge before its application in agricultural fields.

Evaluation of the EMA log kow trigger for fish BCF testing based on data for several human pharmaceuticals

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.

Pistia Stratiotes based heavy metals phytoremediation of a Himalayan river impacted by hydroelectric plant in an Indo Burma hotspot region

ABSTRACT Present study attempts to study the impact of Serlui-B hydroelectric dam on water quality (‘water-energy nexus’) of a Himalayan river and to devise possible phytotechnology for heavy metals remediation. Physico-chemical characteristics of water were analyzed using ‘American Public Health Association (APHA)’ methods while Atomic Absorption Spectrophotometer (AAS) was used for estimation of heavy metals. To this end, concentrations of Fe and Ni were recorded above permissible limit which can impose public health risks. Therefore, phytoremediation experiments were performed by using Pistia stratiotes L. (water lettuce) and effects of Fe and Ni concentrations (1.0, 2.0, and 5.0 mg/L) on photosynthetic pigments were observed. Phytoremediation investigations using 24 aquaria (of 40.5 L) revealed that P. stratiotes was an effective hyperaccumulator of Fe and Ni with maximum removal efficiency of 96.2% and 92%, respectively. In relation to bioaccumulation indices, the bioconcentration factor (BCF) values decreased with increase in Fe and Ni concentrations, whereas the translocation factor (TF) was noted higher at low concentrations and vice versa. Furthermore, the total chlorophyll content and carotenoid levels in P. stratiotes demonstrated negative significant correlation with the rise in Fe/Ni concentrations that may be considered as an adaptive biochemical strategy to mitigate metals induced oxidative stress. The present study can further be extrapolated to field phytoremediation for ameliorating both physico-chemical and metallic contaminants. Last, the role of microbial biodiversity associated with P. stratiotes should be elucidated in future to help achieve SDG 6 and environmental sustainability.

The effect of heavy metal lead (Pb) removal by Hydrilla verticillata, Hygrophila polysperma, and Rotala rotundifolia plants on the height and dry weight of plants

Heavy metal lead is widely used in the industrial world, such as in the manufacture of batteries and cable coatings. Behind its benefits, heavy metal lead has become a pollutant waste that is dangerous for the survival of organisms because it is accumulative and difficult to degrade. This study aims to analyze the effect of aquascape plants removing lead heavy metal concentrations on plant height and dry weight. The experimental design used in this study was a factorial complete randomized design with two factors. The results showed that the plants in all types of treatment had a bioconcentration factor (BCF) value > 1 so the three aquascape plants were categorized as accumulators. This study’s removal of lead and heavy metals influenced aquascape plants’ height and dry weight. The highest increase in height occurred in Hygrophila polysperma (A2B0), while the smallest increase in height occurred in Rotala rotundifolia (A3B0). Measurement of plant dry weight at the end of the study showed that Hydrilla verticillata had the highest dry weight of 1.26 g while the lowest dry weight was owned by Rotala rotundifolia plants at 0.34 g.

Physio-biochemical Behavior and Health Effects of Pepper Plants Subjected to Lead Stress and Their Responses to Remediating Agents as Microbial Activity and Phosphorus

This work assessed the alleviating effects of bacteria (Bacillus subtilis) and phosphorus as environmentally friendly materials on the cultivation of pepper plants in polluted soil with lead (Pb) in forms of PbSO4, and Pb(NO3)2 at rates of 0, 1000, 2000 and 3000 µg Pb/g soil. Pot experiments were conducted to study the growth parameters, some physiological factors, biochemical constituents, and yield attributes, as well as the tolerance index (TI), translocation factor (TF), bioconcentration factor (BCF), and health effects [daily intake of heavy metals (DIM), health risk index (HRI), and carcinogenic risk (CR)]. Increasing the Pb concentration of all Pb salt used in soil severely affected the plant vegetative growth parameters. In comparison with other Pb salt forms, Pb(NO3)2 salt had a strong inhibitory impact. Additionally, the photosynthetic pigments in leaves were negatively impacted by all Pb salt forms. The application of Pb in all salt forms led to changes in the leaf water deficit (LWD), osmotic pressure, and membrane integrity and decreased the total water content, relative water content (RWC), transpiration rate, and leaf succulence. Pollution with Pb salts considerably decreased the yield constituents and various chemical properties of pepper, more so in the presence of Pb nitrate than in the presence of Pb sulfate type. A comparison of the concentration of Pb presence of Pb nitrate was greatly increased than the Pb sulfate in the whole plants. The safe limit of 0.3 mg/kg was exceeded by the Pb concentration in pepper fruits (6.3 and 4.3 mg/kg) cultivated in Pb-contaminated soil [with Pb(NO3)2 and PbSO4, respectively]. Additionally, Pb sulfate had a greater detrimental effect on Pb uptake in several plant organs than other Pb salt forms. The TI of pepper plants treated with salt types was &gt;60% with PbSO4 (75.6%), whereas it was &lt;60% with Pb(NO3)2 (35.2%). The BCF values of pepper plants in the polluted Pb soils varied from 0.10 to 0.41, indicating a moderate accumulator plant. At every level of Pb contamination with all Pb salt types, the sequence of Pb TF values was as follows: roots (TFr) &gt; shoots (TFsh) &gt; fruits (TFf), with TF values &lt; 1. When compared with TFr and TFsh, TFs for shoot to fruits (TFf) had the lowest values (range, 0.07–0.22). The DIM, HRI, and CR values of pepper plants revealed that the Pb of fruit of stressed pepper plants is within safe limits. In addition to reducing the detrimental effects of intolerable Pb levels (2000 and 3000 µg Pb/g soil) on the majority of the aforementioned characters, adding Bacillus bacteria as a bio-agent and phosphorus as a chemo-agent to Pb-polluted soils also stimulated growth, increased yield, controlled plant water relations, protected photosynthetic pigments, and sharply decreased the Pb accumulation in plant organs. The Bacillus bacteria application resulted in some superior characteristics, such as root length, leaf number, leaf length, leaf area, leaf area index, fresh biomass, dry biomass, photosynthetic pigments, quantity yield attributes, reduction Pb accumulation in all plant organs, TI, TFr, TFf, BCF, in health effects trials, whereas phosphorus application improved plant height, leaf width, RWC, LWD, osmotic pressure, total soluble solids, acidity, total carbohydrates, total protein, and TFsh.