Metal Concentrations In Tissues Research Articles

Modified diatomite for soil remediation and its implications for heavy metal absorption in Calendula officinalis

BackgroundAmong different adsorbents, natural and inorganic compounds such as diatomite are important and advantageous in terms of high efficiency and cost-effectiveness, and function in stabilizing heavy metals in the environment. Calendula officinalis, a plant known as a high accumulator of heavy metals, was cultivated in soil treated with varying concentrations of modified diatomite to demonstrate the efficiency of modified diatomite in stabilizating of heavy metals in soils,ResultsThe modification of diatomite aimed to enhance Calendula officinalis adsorptive properties, particularly towards heavy metals such as lead (Pb), Zinc (Zn), Chromium (Cr), Nickle (Ni), and Copper (Cu), common contaminants in industrial soils. The experimental design included both control and treated soil samples, with assessments at regular intervals. Modified diatomite significantly decreased the bioaccumulation of heavy metals in contaminated soils except Zn, evidenced by decreased DTPA extractable heavy metals in soil and also heavy metal concentrations in plant tissues. Using 10% modified diatomite decreased 91% Pb and Cu, 78% Cr, and 79% Ni concentration of plants compared to the control treatment. The highest concentration of Zn in plant tissue was observed in 2.5% modified diatomite treatment. Remarkably, the application of modified diatomite also appeared to improve the nutrient profile of the soil, leading to enhanced uptake of key nutrients like phosphorus (P) 1.18%, and potassium (K) 79.6% in shoots and 82.3% in roots in Calendula officinalis. Consequently, treated plants exhibited improved growth characteristics, including shoots and roots height of 16.98% and 12.8% respectively, and shoots fresh and dry weight of 48.5% and 50.2% respectively., compared to those in untreated, contaminated soil.ConclusionThe findings suggest promising implications for using such amendments in ecological restoration and sustainable agriculture, particularly in areas impacted by industrial pollution.

Olfactory tract/bulb metal concentration in Manganese-exposed mineworkers

BackgroundManganese (Mn) is an essential micronutrient as well as a well-established neurotoxicant. Occupational and environmental exposures may bypass homeostatic regulation and lead to increased systemic Mn levels. Translocation of ultrafine ambient airborne particles via nasal neuronal pathway to olfactory bulb and tract may be an important pathway by which Mn enters the central nervous system. ObjectiveTo measure olfactory tract/bulb tissue metal concentrations in Mn-exposed and non-exposed mineworkers. MethodsUsing inductively coupled plasma-mass spectrometry (ICP-MS), we measured and compared tissue metal concentrations in unilateral olfactory tracts/bulbs of 24 Mn-exposed and 17 non-exposed South African mineworkers. We used linear regression to investigate the association between cumulative Mn exposures and olfactory tract/bulb Mn concentration. ResultsThe difference in mean olfactory tract/bulb Mn concentrations between Mn-exposed and non-Mn exposed mineworkers was 0.16 µg/g (95% CI −0.11, 0.42); but decreased to 0.09 µg/g (95% CI 0.004, 0.18) after exclusion of one influential observation. Olfactory tract/bulb metal concentration and cumulative Mn exposure suggested there may be a positive association; for each mg Mn/m3-year there was a 0.05 µg/g (95% CI 0.01, 0.08) greater olfactory tract/bulb Mn concentration overall, but −0.003 (95% CI −0.02, 0.02) when excluding the three influential observations. Recency of Mn exposure was not associated with olfactory tract/bulb Mn concentration. ConclusionsOur findings suggest that Mn-exposed mineworkers might have higher olfactory tract/bulb tissue Mn concentrations than non-Mn exposed mineworkers, and that concentrations might depend more on cumulative dose than recency of exposure.

Metal concentrations in fish tissues from Kara, Bolshoi Patok, and Maly Patok River basins, Northeastern European Russia

Fish and fish tissue are effective bioindicators due to their sensitivity to pollution and are frequently used for assessing aquatic ecosystem health. Establishing baseline metal concentrations in freshwater fish tissues within aquatic ecosystems is important prior to establishing industrial activities to help determine potential future industrial impacts. Historically, North-Eastern European Russia has been an area with relatively low levels of industrial development and is still in pristine condition. In this region, the noise-to-background ratio for industrial contaminants may be disproportionately high. This study measured baseline metal concentrations in freshwater fish tissues collected from three study sites (the Bolshoi Patok, Maly Patok and Kara Rivers) in northeastern European Russia as bioindicators of overall aquatic ecosystem health. Seven fish species, namely, European Grayling, Arctic Char, Whitefish, Perch, Pike, Roach, and Peled, were studied over a three-year period between 2000 and 2003. The copper (Cu), lead (Pb), cadmium (Cd), and zinc (Zn) concentrations were analysed in fish tissue samples. Metal concentrations measured in fish tissues in this study were comparable to those measured at remote sites in Alaska, the United States and Slovenia. Despite the small variation between the sampling sites, the metal concentrations were relatively low and considered to be in pristine condition. Metal concentrations measured in fish tissues in this study represent baseline conditions, which will be important for comparison against monitoring programmes should the region experience future industrial development.

Ecotoxicology of heavy metal contamination of Neotropical bats.

Although bats are responsible for many ecosystem services on which humans depend, they are frequently exposed to multiple anthropogenic stressors. Heavy metal (HM) exposure is an emerging threat of great significance to bats, yet the toxicity threshold for most metallic elements remains unknown. The greatest diversity of bats worldwide is in the Neotropical region, where ecotoxicological studies are scarce. Thus, this review provides a current overview of the knowledge available on HMs contamination of Neotropical bats. Analysis of the results of 17 articles published between 2000 and 2023 documented a trend of increasing interest in the topic, although it is incipient and in few countries. Of the 226 species known for the Neotropics, 95 have been investigated for metal concentrations. Seven different matrices were used to assess concentrations of heavy metals in tissues, with fur being the subject of eight studies, highlighting the search for non-invasive analysis. Twenty-one HMs were detected in bats, with mercury being the most common. The highest concentrations of this HM were detected in insectivorous/omnivorous bats, highlighting its magnification in this trophic guild compared to frugivorous bats. Copper, lead, and cadmium did not differ significantly among the other trophic guilds. This review shows that there is knowledge about concentrations of heavy metals in several Neotropical species, but knowledge about the impact of these concentrations on bat health is limited, which highlights the need for research to determine critical concentrations that cause damage to bat health, and that guide conservation actions for their populations, as well as environmental monitoring actions for these pollutants.

Threat of heavy metal pollutants and parasites to freshwater fish with special reference to their risk of cancer to humans in Egypt

Understanding how pollution and parasite infection work together to stress their hosts' health raises the possibility of a danger to aquatic life and humans. This study examined two freshwater fish species, Clarias gariepinus, and Oreochromis niloticus, at El-Abbasa Fish farm in Sharkia Governorate of Egypt. to determine their heavy metal content, parasite frequency, and potential health risks. Parasitological investigations revealed higher parasite prevalence in C. gariepinus, with trematodes being the most prevalent. Histopathological examinations displayed severe alterations in infected fish, including gill necrosis, intestinal damage, liver degeneration, and muscle necrosis. Moreover, heavy metal analysis. Heavy metals levels in water, Fe, Zn, Pb, Cu, As, and Cd levels were 0.95 ± 0.04, 0.75 ± 0.03, 0.14 ± 0.02, 0.09 ± 0.01, 0.07 ± 0.01, and 0.03 ± 0.01 mg/L, respectively. Sediment samples showed Cd as the lowest (2.38 ± 0.94 μg/g dry wt. basis) and Fe as the highest (241.01 ± 6.39 mg/kg dry wt. basis). The sequence of heavy metal concentrations in both water and sediment was Fe > Zn > Pb > Cu > As > Cd. Significant differences were found among metals in water and sediment (p < 0.05). Heavy metal concentrations in fish tissues followed the order liver > muscles > gills > intestine Iron was the most abundant, while cadmium was the lowest is the order in which bio-accumulation factors (BAF) between water and fish tissues followed a descending order: BAF-Liver < BAF-Gills < BAF-Intestine < BAF-Muscles. The sequence of heavy metal accumulation in tissues was BAF-Fe > BAF-Pb > BAF-Cd > BAF-As > BAF-Cu > BAF-Zn, indicating varying degrees of accumulation across different metals and tissues and bio-sedimentation (BSF) of metals in fish tissues are the order of heavy metal concentration within tissues was BSF-Cd > BSF-As > BSF-Fe > BSF-Zn > BSF-Cu > BSF-Pb. Additionally, data were recoded to reflect histological changes in several fish organs. The estimated daily intake of heavy metals (EDI-HMs) was far lower than the permissible tolerated daily intake (PTDI) limits, which were set by international authorities at 70 kg of body weight. As the hazard index value is below 1, the THQ and HI associated with the consumption muscle of fish demonstrate negligible non-carcinogenic harm to residents' health. Contrarily, As, and Cd pose a cancer threat for kids and adults who eat muscular fish, and it needs to be viewed as a warning sign from the perspective of data indices and human health.

Bycatch and pollution are the main threats for Burmeister's porpoises inhabiting a high-industrialized bay in the Humboldt Current System

Pollution and bycatch are two of the main threats for cetaceans worldwide. These threats are exacerbated for nearshore species particularly for those in regions with intense industrial and fishing activities. Burmeister's porpoise is endemic to South America, has a Near Threatened conservation status because of long-term mortality in fisheries. Burmeister's porpoise occur in Mejillones Bay, northern Chile, a hot spot for heavy metals pollution from the mining industry and an intense industrial and artisanal purse-seine fishing area. From 2018 to 2021, we conducted systematic marine surveys to assess the abundance, distribution and habitat use of Burmeister's porpoises. We responded to stranding reports from 2018 to 2022, and necropsied nine individuals. From five of these, we analyzed the metal concentrations (As, Cd, Cr, Cu, Pb, Hg, Se and Zn) in muscle and skin tissues. Results showed an abundance of 76.17 individuals (CV = 25.9%) and an average density of 0.45 individuals/km2 (CV = 26%). Burmeister's porpoises were observed year round, 22.2% were mother-calf pairs present in austral summer at an average of 90.6 m depth in the southwestern bound of the bay. Two-thirds of stranded specimens died due to bycatch and one died due to bottlenose dolphin (Tursiops truncatus) attack. We report a dead Burmeister's porpoise positive for avian flu virus A (H5N1). Metals analyzed were found in muscle and skin tissues of stranded Burmeister's porpoises in the following order (Zn > Cu > Cr > As > Hg > Pb > Cd). Although we could not assess pollution as a cause of mortality, Cr, As and Pb concentrations exceeded the concentrations found in other porpoises species worldwide. We conclude that bycatch and pollution as the main threats for Burmeister's porpoise survival in northern Chile. Future studies should investigate the use of acoustic deterrent alarms to mitigate the bycatch in the bay and consider the Burmeister's porpoise as a sentinel species of pollution in northern Chilean coast.

Mechanism and ecological environmental risk assessment of peroxymonosulfate for the treatment of heavy metals in soil

Oxidation technologies based on peroxymonosulfate (PMS) have been effectively used for the remediation of soil organic pollutants due to their high efficiency. However, the effects of advanced PMS-based oxidation technologies on other soil pollutants, such as heavy metals, remain unknown. In this study, changes in the form of heavy metals in soil after using PMS and the risk of pollution to the ecological environment were investigated. Furthermore, two risk assessment methods, the mung bean germination toxicity test and groundwater leaching soil column test, were employed to evaluate the soil before and after PMS treatment. The results showed that PMS has a strong ability to degrade complex compounds, enabling the transformation of heavy metals, such as Cd, Pb, and Zn, from stable to active states in the soil. The risk assessments showed that PMS treatment activated heavy metals in the soil, which delayed the growth of plants, increased heavy metal content in plant tissues and the risk of groundwater pollution. These findings provide a new perspective for understanding the effects of PMS on soil, thus facilitating the sustained and reliable development of future research in the field of advanced oxidation applied to soil treatment.

Determination of Heavy Metals in Etroplus suratensis from Koggala Lagoon in Southern, Sri Lanka

Fish is one of the best organisms in many scientific studies to evaluate heavy metal pollution and human health hazards as they are well-understood organisms in the aquatic environment. The present study was carried out to examine the level of heavy metals in different tissues of Etroplus suratensis (Green chromide) in Koggala lagoon, Sri Lanka. Atomic absorption spectrophotometer (AAS) was used to determine the levels of copper (Cu2+), cadmium (Cd+3), lead (Pb+2) and Chromium (Cr+3) ions in the different tissues (skin, liver, gill, and flesh) of fish belonging to three different sizes; small (7.8-10.2) cm, medium (14.1-16.6) cm, and large (19.8-25.2) cm. The number of thirty-six fish were collected from the lagoon randomly. According to available sizes, 12 fish for each size class were used for the analysis. Furthermore, the histological analysis was carried out to identify the changes at the tissue levelling the gill and liver of fish in three different size classes. Heavy metal concentration in fish samples were compared with the standard levels of heavy metals. Heavy metal concentrations in body tissues of three different body sizes of fish were found to be mainly in the order of Cu&gt;Pb&gt;Cr&gt; Cd. The highest concentrations (P&lt;0.05) of heavy metals were found in the fish flesh and skin, while the lowest concentrations were found in the gills. The range of heavy metal concentrations (g g-1 dry weight) in body tissue of small size, E. suratensis fish were, Cu: 0.0443-0.6210, Cd: 0.0110–0.0214, Pb: Below Detection Level (BDL)- 0.46 and Cr: BDL-39.633, Medium size fish were, Cu: 0.0713–0.6210, Cd: 0.0134-0.0170, Pb: BDL-40.906, Cr: 0.0014–0.0500 and large fish were, Cu: 0.0553–0.345, Cd: 0.0110–0.0256, Pb: 0.0204–0.2103 and Cr: 0.0194–0.0773. However, Cd, Cr and Pb concentrations of flesh tissues were under the standard recommended limits referred by the FAO. Through the Cu concentration in flesh, tissues exceeded the standard limits of FAO. It is not considered as a toxic heavy metal. Histological analysis revealed that the deviation of shape of hepatic cells in the liver may due to the exposure to heavy metals in the lagoon. According to the overall result, biomagnification nature of heavy metals, and the consumption of E. suratensis in the Koggala the bioaccumulation and lagoon may create health hazards to consumers. &#x0D; Keywords: Green chromide, Koggala Lagoon, Heavy metals, Histology

The association between trace metals in both cancerous and non-cancerous tissues with the risk of liver and gastric cancer progression in northwest China

Liver cancer and gastric cancer have extremely high morbidity and mortality rates worldwide. It is well known that an increase or decrease in trace metals may be associated with the formation and development of a variety of diseases, including cancer. Therefore, this study aimed to evaluate the contents of aluminium (Al), arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se), and zinc (Zn) in cancerous liver and gastric tissues, compared to adjacent healthy tissues, and to investigate the relationship between trace metals and cancer progression. During surgery, multiple samples were taken from the cancerous and adjacent healthy tissues of patients with liver and gastric cancer, and trace metal levels within these samples were analysed using inductively coupled plasma mass spectrometry (ICP-MS). We found that concentrations of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn in tissues from patients with liver cancer were significantly lower than those in healthy controls (P < 0.05). Similarly, patients with gastric cancer also showed lower levels of Cd, Co, Cr, Mn, Ni, and Zn—but higher levels of Cu and Se—compared to the controls (P < 0.05). In addition, patients with liver and gastric cancers who had poorly differentiated tumours and positive lymph node metastases showed lower levels of trace metals (P < 0.05), although no significant changes in their concentrations were observed to correlate with sex, age, or body mass index (BMI). Logistic regression, principal component analysis (PCA), Bayesian kernel regression (BKMR), weighted quantile sum (WQS) regression, and quantile-based g computing (qgcomp) models were used to analyse the relationships between trace metal concentrations in liver and gastric cancer tissues and the progression of these cancers. We found that single or mixed trace metal levels were negatively associated with poor differentiation and lymph node metastasis in both liver and gastric cancer, and the posterior inclusion probability (PIP) of each metal showed that Cd contributed the most to poor differentiation and lymph node metastasis in both liver and gastric cancer (all PIP = 1.000). These data help to clarify the relationship between changes in trace metal levels in cancerous liver and gastric tissues and the progression of these cancers. Further research is warranted, however, to fully elucidate the mechanisms and causations underlying these findings.

Trace Metals in the Mussel Mytilus californianus from the West Coast of Baja California, Mexico.

This study assessed the concentrations of trace metals in tissues of Mytilus californianus from the west coast of Baja California, Mexico, during the cold and warm seasons. The concentrations of silver, cadmium, copper and zinc in mussel tissues were measured using Atomic Absorption Spectrophotometry. Silver concentrations ranged from 0.03 to 0.48µg/g dry weight (d.w.) with significantly higher values registered at sites close to densely populated areas. Cadmium, copper, and zinc concentrations ranged from 0.57 to 7.83µg/g d.w., 3.71 to 621µg/g d.w., and 57.54 to 124.55µg/g d.w., respectively. According to the WHO, values of copper and zinc were within acceptable limits. The maximum values of cadmium, however, exceeded the recommended limits set by the European Commission (2014). The human health risk of the metals analyzed was low (THQ and HI < 1). The regular monitoring of trace metals in M. californianus is recommended for a more definitive evaluation of contaminants.

Heavy metal concentration in soft tissues of freshwater clam (Galatea paradoxa Born 1778) from Diebu Creek, Bayelsa State, Nigeria

Heavy metal concentration in soft-tissues of freshwater clam (Galatea paradoxa) from Diebu Creek, Bayelsa State, Nigeria, was investigated. Clam samples were obtained from the creek for three consecutive months from February to April 2022 and categorized into three class sizes: big (&gt;50 mm), medium (36 - 50 mm) and small (20-35mm). Samples were analysed for cupper (Cu), lead (Pb), iron (Fe) and zinc (Zn). The results show that the big-size clams (17.37±0.01 mg/kg) had the highest copper concentration and small-size clams the lowest concentration (0.00±0.00 mg/kg). For lead, the big-size clams (1.48±2.52 mg/kg) also recorded the highest concentration and small-size clams (0.32±0.02 mg/kg) the lowest concentration. For iron, the highest concentration was established in big-size clams (21.81±0.17 mg/kg) and lowest concentration in small-size clams (3.55±0.10 mg/kg). In the case of zinc, the highest concentration was likewise noticed in big-size clams (30.00±0.16 mg/kg) and lowest concentration in small-size clams (0.14±0.00 mg/kg). Heavy metal concentration mean values recorded from the different sizes of clams portrayed a significant difference (P&lt;0.05) between the mean values of big-size clams from the medium and small size clams. The concentration level of metals in the clams from Diebu Creek were within the acceptable limits therefore, meets the acceptable standards and are safe for human consumption. Heavy metals generally have relatively high density and are poisonous even at low concentrations therefore should be curtailed to the barest minimum level to reduce seafood contamination in water bodies particularly in Diebu Creek and its environs in Bayelsa State.

Placental cellular composition and umbilical cord tissue metal(loid) concentrations: A descriptive molecular epidemiology study leveraging DNA methylation

The placenta is a mixture of cell types, which may regulate maternal-fetal transfer of exogenous chemicals or become altered in response to exposures. We leveraged placental DNA methylation to characterize major constituent cell types and applied compositional data analysis to test associations with non-essential metal(loid)s measured in paired umbilical cord tissue (N = 158). Higher proportions of syncytiotrophoblasts were associated with lower arsenic, whereas higher proportions of Hofbauer cells were associated with higher cadmium concentrations in umbilical cords. These findings suggest that placental cellular composition influences amounts of metal(loid)s transferred to the fetus or that prenatal exposures alter the placental cellular makeup.

Metals and arsenic distribution in stray dogs' tissues around a lead-zinc mine in Kabwe, Zambia.

Metal contamination poses a threat to human, animal, and environmental health. The purpose of the current study was to assess the accumulation of toxic and trace metal concentrations in tissues of stray dogs in Kabwe, a town known for lead pollution due to a long history of lead and zinc mining. Brain, spleen, heart, stomach, stomach content, small intestine, kidney, liver, and bone samples were collected from 29 stray dogs (14 from locations within 3km of the mine and 15 from sites 7km away from the mine) after necropsy. Inductively coupled plasma mass spectrometry was used to analyze toxic metals, arsenic (As), cadmium (Cd), and lead (Pb), and trace elements, copper (Cu) and zinc (Zn). The lungs (0.117 ± 0.114mg/kg dry weight), kidney (7.515 ± 8.830mg/kg dry weight), and bone (41.68 ± 66.83mg/kg dry weight) were found to have the highest concentrations of As, Cd, and Pb, respectively. In contrast, higher Cu and Zn concentrations were measured in the liver than in other tissues. In all tissues analyzed, tissues sampled from dogs near the mine had significantly higher mean concentrations of Cd and Pb than dogs far away. Neither sex nor age-related differences were observed in the distribution of metals in most tissues. There were significant associations among toxic (Pb and Cd) and trace metals (Cu and Zn). In the kidney, Cd positively correlated with Pb (ρ = 0.534) and Zn (ρ = 0.600), whereas in the liver, Cu correlated with Zn (ρ = 0.565). The current study's findings suggest that environmental pollution is still a problem in Kabwe, and environmental remediation is needed to address the pollution.

Influence of mother’s genotype on the concentration and variability of triiodothyro- nine in landrace pigs

One of the leading roles in the hormonal system of the body of pigs in terms of functional significance is played by the thyroid gland, which, through the hormone triiodothyronine, has a complex effect on all systems, organs and physiological processes while controlling the metabolism and energy in the animal’s body. The impact of maternal genotype on the concentration and variability of triiodothyronine in complete siblings of Landrace pigs was studied. For the study, blood serum samples were taken from 33 pigs using the vacuum method from the jugular vein. Blood samples were taken according to generally accepted practices. The studies were carried out in the laboratory of the biochemistry of the Novosibirsk State Agrarian University using the technique of competitive enzyme immunoassay with a set of reagents “Steroid ELISA-triiodothyronine” to quantify the concentration of triiodothyronine in blood serum. Enzyme immunoassay was performed on a Thermo Scientific Multiskan FC analyser. In pig breeding, the content of heavy metals in water, soil, feed, organs and tissues was constantly monitored. The concentration of chemical elements did not exceed the MPC level. Statistical processing of experimental data was carried out using standard methods of descriptive statistics and the statistical programming language or data analysis environment RStudio (using the functions: descrstats, summary, sd, read.table, write. table, aes). The strength of the influence of the genotype of mothers of the Landrace breed on the triiodothyronine content in complete siblings in the conditions of Western Siberia was established, which amounted to 4.6 %. In some mothers’ offspring, the triiodothyronine level was 1.9 and 1.8 times higher than in others. Two clusters of mothers were identified according to the concentration of triiodothyronine in complete siblings, which included three groups of mothers with an average level of 2.26 nmol/l and five groups with the attention of 1.30 nmol/l. The reference limits of the triiodothyronine level in Landrace pigs in the conditions of Western Siberia were established.

Human health risk assessment of heavy metals accumulation in different genders and tissues of whiting fish (Merlangius merlangus euxinus Nordmann, 1840) from Rize, Turkey

The contamination of fish resulting from marine pollution is a major concern, as it poses potential adverse effects on human health. Therefore, heavy metal concentrations (Cr, Fe, Ni, Cu, Zn, and Pb) in different genders and tissues (muscle, liver, gonads and gills) of whiting fish collected from fish markets in Rize province were determined by Inductively–coupled plasma optic emission spectrometry (ICP–OES). The concentration ranges of heavy metals in all tissue samples, based on the overall average, were as follows (mg/kg wet weight): Cr: 0.081–0.25, Fe: 2.3–40, Ni: 0.070–0.095, Cu: 0.33–1.01, Zn: 3.0–20, and Pb: 0.015–0.043. The results indicated that the liver and gills exhibited a higher metal accumulation capacity compared to other tissues, whereas the muscle consistently displayed the lowest metal concentrations. The metal concentrations in the muscle were found to be below the maximum permissible levels set by international organizations for seafood. Additionally, calculated estimated daily intake (EDI), metal pollution index (MPI), target hazard quotient (THQ), total exposure hazard index (HI), and target carcinogenic risk (TR) indicate no potential risk to humans from whiting fish consumption.

A new hyperaccumulator plant (Spergularia rubra) for the decontamination of mine tailings through electrokinetic-assisted phytoextraction

The screening of new effective metal hyperaccumulators is essential for the development of profitable phytoremediation projects in highly degraded environments such as mining areas. The goal of this research was to analyze the phytoextraction potential of the native plant Spergularia rubra to decontaminate and eventually recover metals (phytomining) from the mine tailings (belonging to an abandoned Pb/Zn Spanish mine) in which it grows spontaneously. To do so, the ability of this plant species to accumulate metals was evaluated both under natural conditions and through simple and electrokinetically assisted phytoextraction tests using alternating current and different combinations of voltage gradient (1/2 V cm−1) and application time (6/12 h per day). The complete duration of the greenhouse trial was 64 days, although alternating current was applied only during the last 14 days. The results obtained demonstrated the exceptional effectiveness of S. rubra for metal hyperaccumulation and growth without affecting toxicity in highly contaminated mining waste. Zn was the metal accumulated to a higher extent in the shoots, reaching concentrations up to 17,800 mg kg−1; Pb was mainly accumulated in the roots reaching a maximum concentration of 8709 mg kg−1. Cu and Cd were accumulated to a lesser extent but the bioconcentration factors were much >1. It has been proved that S. rubra is a hyperaccumulator species for Zn and Cd both in natural and greenhouse conditions and, very probably, Pb in wild conditions. The application of AC current did not significantly increase metal concentrations in plant tissues but it was able to increase the aerial biomass of S. rubra by 49.8 %. As a result, the phytoextraction yields of all metals were significantly improved as compared to wild conditions (up to 86 % for Zn). It could open new expectations about the economic viability of recovering high-value metals from mine tailings.

Heavy Metals Assessment and Health Risk to Consumers of Two Commercial Fish Species from Polyculture Fishponds in El-Sharkia and Kafr El-Sheikh, Egypt: Physiological and Biochemical Study.

Metal pollution is a major environmental concern worldwide, especially in Egypt. The aquaculture industry uses widespread artificial feeds to stimulate fish production, leading to metal accumulation in the aquatic environment. Heavy metal concentrations (HMCs) in sediments, water, and tissues were studied to study the effect of pollution levels on heamatological, and biochemical, immunological aspects of farmed fish as well as on human health. Results declared that the HMC levels in the water and sediment were significantly different between El-Sharkia and Kafr El-Sheikh fishponds (T-test, p < 0.05). This was supported by the metal pollution index in the water and sediment, indicating that El-Sharkia fishponds (ES fishponds) were more contaminated than Kafr El-Sheikh fishponds (KES fishponds). Also, HMCs in fish tissues were significantly increased in fish cultivated in ES fishponds than in KES fishponds. Haematological, immunological, and biochemical alterations of Bolti (Oreochromis niloticus) and Topara (Chelon ramada) fish were significantly different within the different fish species as well as the different fishponds. From the human health perspective, the THQ-HMC and HI-HMC associated with the consumption of muscle suggest a safe non-carcinogenic risk to human health. In contrast, cadmium poses a cancer risk to children who consume the muscular tissue of Bolti fish from ES fishponds, which should be regarded as a warning sign based on data indices and a human health perspective.In order to minimise HMC pollution in the aquaculture sector, it is advisable to take possible assessments and carry out continuous monitoring considering international WHO/FAO assessments.

Phytoextraction potential of herbaceous plant species and the influence of environmental factors – A meta-analytical approach

Heavy metals account for a notable share of soil and water body contaminations. For restoring contaminated soils, phytoremediation is considered an eco-friendly and sustainable practice. However, the implementation in the field requires a well-thought-out plant selection and comprehensive knowledge of the influence of various environmental factors. Therefore, a quantitative evaluation of 330 studies was done using a meta-analytical approach. The systematic assessment included the calculation of bioconcentration factors for roots and shoots (BCFROOT, BCFSHOOT) and translocation factors (TF) of 48 herbaceous species, as well as the identification of the most important soil and plant factors that regulate the heavy metal uptake into plant tissues. The results showed substantial variations in roots' and shoots' heavy metal uptake capacity among the diverse plant species. The uptake also varied depending on the type of heavy metal. Most species revealed a higher accumulation of heavy metals in roots than shoots, indicating a limited heavy metal transport from below-ground into above-ground plant parts. Among the different heavy metals, Cd showed the highest median BCFSHOOT and BCFROOT, followed by Zn, Cu, Ni, Cr, and Pb, which can partly be explained by the solubility and plant availability of the elements. The strongest significant and positive correlations of heavy metal contents in plant tissues were found with the total and available soil content. Clay and silt content showed a weak negative, and sand content a slight positive correlation. Further, root, shoot and total biomass revealed weak negative correlations to the plants' heavy metal contents. Overall, this study forms a basis for the minimum accumulation capacities of various species and thus makes an essential contribution to the planning and practical application of phytoremediation projects.

Evaluating metal phytorremediation and biondication potential of Spartina alterniflora in a South American estuary

Soil metal pollution has been widely studied in salt marshes but mainly regarding non-essential metals. The aim of this study was to assess the levels of two essential metals (Fe and Mn) and one non-essential one (Cd) in Spartina alterniflora salt marshes in a South American estuary in order to evaluate the potential of this species as a phytoremediator and/or bioindicator of Fe, Mn and Cd and to analyze the distribution of these metals according to the edaphic conditions. The metals present in the soils varied among the three sites studied according to the content of organic matter and fine sediments. In comparison with other Spartina-dominated salt marshes worldwide, in this study Fe and Mn were approximately in the same range, whereas Cd levels were always lower, with a high number of samples below the method detection limit (MDL). All metals were highly correlated with each other suggesting an association of Cd with Mn and Fe oxides/hydroxides or sulfides and/or a common anthropogenic source. Metals in plant tissues also varied from site to site and between the aboveground and belowground tissues. Compared to the metal levels in Spartina tissues in other salt marshes, our levels of Fe and Mn were in the same range, whereas the Cd levels were lower, among most samples, especially those from aboveground tissues that were below the MDL. The bioconcentration factor (metal in belowground tissues/metal in soil) was always lower than one for Fe and Mn meaning that there is no accumulation of these metals in belowground tissues, but this factor for Cd was sometimes higher than one, even as high as 3.45, implying that S. alterniflora can accumulate this metal in its tissues, pointing to a potential role of this species in Cd phytoremediation. Translocation factors (metal in aboveground tissues/metal in belowground tissues) were always lower than one for Fe and could not be calculated for Cd but were usually higher than one for Mn, showing the role of this element in photosynthetic tissues and a possible function of this species for phytoextraction of Mn. In most samples the Fe levels in plant tissues were higher than the permissible levels reported in the literature, suggesting a potential role of S. alterniflora in Fe phytoremediation. No correlation was observed between metal concentrations in soils and aboveground tissues; therefore, S.alterniflora is not a good bioindicator for the metals studied. Although our results are not conclusive, they reinforce the importance of local edaphic conditions on the behavior of metals in salt marshes and shed light on the potential role of S. alterniflora in the phytoremediation of highly toxic metals such as Cd or poorly studied metals such as Fe and Mn.

Bioaccumulation of some Heavy Metals (Cadmium, Copper and Zinc) in Three Tissues of the Common Carp Cyprinus carpio L. Collected from a Mud Culture

The current study was conducted to find out the bioaccumulation of the three elements cadmium, copper and zinc, in tissues of the common carp Cyprinus carpio L., they were gills, muscles and viscera. Cultivated in three mud ponds in Thi Qar Governorate - Nasiriyah city, Shatrah district, in the village of Al-Ajjah Al-Buhan, near Al-Ghamouqa Valley, it is 55 km away from the center of Al-Nasiriyah. The fish were distributed to the lakes with uniform densities for the period from 5/11/2022 to 5/4/2023, by 1000 fish/m3 were used, it was divided into three lakes equally, with an average weight of 20 gm. A standard local diet was used to feed the fish, standard methods were used to estimate the concentrations of heavy metals in tissues, by a flame atomic absorption spectrometer. Results were recorded in tissues for cadmium in gills, muscles and viscera. The highest values were in the autumn season for gills and muscles, respectively (12.13-12.77 μg/gm dry weight). The highest concentration recorded in spring for tissues was (8.3 μg/gm dry weight). Copper recorded the highest value in gills, muscles and viscera, in the spring season (222.14, 334.77 and 110.65μg/gm dry weight), respectively. Zinc recorded high concentrations in the gills, viscera, and muscles, i In autumn (350.34, 259.17 and 303.34 μg/g dry weight), respectively. The results showed that the accumulation of elements; Heavy was in the following order: Zinc > copper > cadmium. Cadmium: gills > viscera > muscles. Copper: gills > muscles > viscera. Zinc: gills > viscera > muscles.