Heavy Metals Cadmium Research Articles

Presence of Heavy Metals in Irrigation Water, Soils, Fruits, and Vegetables: Health Risk Assessment in Peri-Urban Boumerdes City, Algeria.

This study investigates heavy metal contamination in soils, irrigation water, and agricultural produce (fruits: Vitis vinifera (grape), Cucumis melo var. saccharimus (melon), and Citrullus vulgaris. Schrade (watermelon); vegetables: Lycopersicum esculentum L. (tomato), Cucurbita pepo (zucchini), Daucus carota (carrot), Lactuca sativa (lettuce), Convolvulus Batatas (potato), and Capsicum annuum L. (green pepper)) in the Boumerdes region of Algeria. The concentrations of seven heavy metals (cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), and zinc (Zn)) in soil and food samples were analyzed using atomic absorption spectrometry. Health risks associated with these metals were evaluated through the estimated daily intake (EDI), non-carcinogenic risks (using target hazard quotient (THQ), total target hazard quotient (TTHQ), and hazard index (HI)), and carcinogenic risks (cancer risk factor (CR)). Statistical analyses, including cluster analysis (CA) and Pearson correlation, were conducted to interpret the data. The results revealed the highest metal transfer as follows: Cd was most significantly transferred to tomatoes and watermelons; Cr to carrots; Cu to tomatoes; and Fe, Ni, Pb, and Zn to lettuce. Among fruits, the highest EDI values were for Zn (2.54·10-3 mg/day) and Cu (1.17·10-3 mg/day), with melons showing the highest Zn levels. For vegetables, the highest EDI values were for Fe (1.68·10-2 mg/day) and Zn (8.37·10-3 mg/day), with potatoes showing the highest Fe levels. Although all heavy metal concentrations were within the World Health Organization's permissible limits, the HI and TTHQ values indicated potential health risks, particularly from vegetable consumption. These findings suggest the need for ongoing monitoring to ensure food safety and mitigate health risks associated with heavy metal contamination.

Enhanced phytoremediation of cadmium-contaminated soil using chelating agents and plant growth regulators: effect and mechanism.

The heavy metal cadmium (Cd) is a major threat to food safety and human health. Phytoremediation is the most widely used remediation technology, and how to improve the remediation efficiency of phytoremediation has become a key issue. In this study, we constructed an intensive phytoremediation technology for remediation of Cd-contaminated soil with biodegradable chelating agent and plant growth regulator combined with maize and investigated the mechanism of this technology. The results showed that the best remediation effect was achieved in the treatment with 10-6 mol l-1 gibberellic acid (GA3) and 6 mmol kg-1 aspartate diethoxysuccinic acid (AES) combined with maize. In this treatment, the total biomass and extraction efficiency of maize were 3.6 and 8.67 times higher than those of the control, respectively, and the antioxidant enzyme activities of maize were also increased. The soil was enriched with dominant bacterial genera that promote plant growth and metabolism and tolerance to heavy metal stress, which in turn promoted maize growth and Cd accumulation. Structural equation modelling results indicated a large effect of plant Cd concentration and plant antioxidant enzyme activity on plant Cd extraction. The enhanced phytoremediation technology showed good potential for safe use of Cd-contaminated soil.

Evaluating Household Hazardous Waste Generation, Composition, and Health Risks in an Urban Municipality

This study aimed to assess the generation rate and composition of household hazardous waste (HHW) in Nakhon Si Thammarat Municipality, Thailand. A questionnaire survey was conducted to collect data on HHW generation and disposal practices from households in the municipality. Soil samples were collected and analyzed for heavy metals (cadmium, chromium, mercury, nickel, and lead) and PCBs contamination. The potential health risks from ingestion exposure associated with heavy metals and polychlorinated biphenyls (PCBs) contamination in the soil were evaluated. The result revealed that in 2023, the HHW generation rate was 11.95 kg/household/year, with the highest percentages occurring of electronic waste (17.40%), fluorescent lamps (16.98%), spray cans (12.38%), cleaning products (11.30%), and engine oil and lubricant oil products (9.87%). The majority of residents (92.90%) disposed of hazardous waste and general waste together in public waste containers. However, the health risk assessment indicated that the levels of heavy metals and PCBs in the soil were within the safe acceptable range for residents, with a total lifetime cancer risk from ingestion exposure of less than 1E-06 for both adults and children. The findings highlight the need for improved waste separation practices and the implementation of effective hazardous waste management strategies to minimize potential health risks and environmental impacts. This study serves as a basis for developing targeted interventions and policies to enhance household hazardous waste management in the municipalities and similar urban areas in Thailand. Doi: 10.28991/HEF-2024-05-03-011 Full Text: PDF

OsPLDα1 mediates cadmium stress response in rice by regulating reactive oxygen species accumulation and lipid remodeling

Lipid remodeling is crucial for various cellular activities and the stress tolerance of plants; however, little is known about the lipid dynamics induced by the heavy metal cadmium (Cd). In this study, we investigated the phospholipid profiles in rice (Oryza sativa) under Cd exposure. We observed a significant decline in the total amounts of phosphatidylcholine and phosphatidylserine, contrasted with an elevation in phosphatidic acid (PA) due to Cd stress. Additionally, Cd stress prompted the activation of phospholipase D (PLD) and induced the expression of PLDα1. OsPLDα1 knockout mutants (Ospldα1) showed increased sensitivity to Cd, characterized by a heightened accumulation of hydrogen peroxide in roots and diminished PA production following Cd treatment. Conversely, PLDα1-overexpressing (OsPLDα1-OE) lines demonstrated enhanced tolerance to Cd, with suppressed transcription of the respiratory burst oxidase homolog (Rboh) genes. The transcription levels of genes associated with Cd uptake and transport were accordingly modulated in Ospldα1 and OsPLDα1-OE plants relative to the wild-type. Taken together, our findings underscore the pivotal role of OsPLDα1 in conferring tolerance to Cd by modulating reactive oxygen species homeostasis and lipid remodeling in rice.

Research on the aging mechanism of polypropylene nonwoven geotextiles under simulated heavy metal aging scenarios

We conducted accelerated aging experiments on two types of polypropylene (PP) nonwoven geotextiles (filament geotextile and staple fiber geotextile), immersing them in five different simulated liquids at temperatures of 25 °C, 55 °C, and 85 °C for 200 days. At 85 °C and a pH of 1, the tensile strength and elongation at break of PP filament materials decreased by 95% and 86%, respectively. The presence of heavy metals(arsenic and cadmium), speeds up the aging process in both types of PP geotextiles. Under identical conditions, these heavy metals can increase the loss of tensile strength in geotextiles by more than 7% in 200 days. Increases in temperature, acidic environment, and heavy metal concentration all contribute to faster aging of these geotextiles. Although filament geotextiles exhibit higher tensile strength and elongation at break, staple fiber geotextiles show a lower rate of tensile strength loss during aging and better maintain their tensile strength in high-temperature acidic conditions. During the aging process, cross-linking and recrystallization occur, both of which control the aging rate and the formation of microplastics.

Quality Parameters of Plum Orchard Subjected to Conventional and Ecological Management Systems in Temperate Production Area

Environmental protection, global food security, and nutritional quality are critical issues for worldwide sustainable development. Plums (Prunus domestica L.), well-known for their rich nutritional content and distinct phytochemical profile, have received increased attention due to their potential health benefits. The present study evaluates the ecological and conventional management systems of quality parameters in three plum varieties—Tuleu Gras, Record, and Centenar—and establishes suitable practices to improve fruit quality and yields. The fruit morphometric features (color, firmness, soluble solid content, titratable acidity, and total sugar) were analyzed during their raw fruit state, while different fruit-sample extracts were assessed for phytochemical compounds and heavy metal concentrations, specifically, zinc, copper, nickel, and cadmium. The results show a wide variability in the examined characteristics among management practices that differentially accumulated throughout the ripening phase and significantly influenced the nutritional value of the plum fruit. The application of an ecological management practice yielded small plum fruits (38 g) and maintained a more consistent and vigorous fruit color compared with the conventional system (83 g). Moreover, ecological plums have higher antioxidant activities, total polyphenols, and flavonoids (21.70–25.54 µM Trolox/g of dw, 3.89–7.76 mg GAE/ g of dw, and 1.45–3.65 mg CE/g of dw, respectively). Among the content of metals in the plum fruit, copper exhibited the highest concentrations (0.83–1.21 mg/kg), while cadmium was detected at the lowest levels (0.006–0.009 mg/kg). The potential health implications of heavy metals, by calculating their estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI), for both adults and children were also analyzed. The EDI values of accumulated elements in the plum fruits followed the order of Cu > Zn > Ni > Cd with no concern for human health (THQ and HI < 1). According to this study’s findings, fruit quality parameters are significantly higher in ecological plums, providing a compelling argument for adopting sustainable agricultural practices. These results highlight the importance of selecting sustainable agricultural practices, not only to safeguard the environment but also to ensure high-quality products suitable for human consumption.

Synergistic mechanisms of lignin-based novel materials and leaf-surface selenium fertilizer in alleviating drought and heavy metal stress

Drought and heavy metal stress threaten sustainable crop production and ecosystems, highlighting the urgent need for resilient agricultural practices. The synthesis of lignin-based hydrogel (L-GH) and foliar selenium (Se) offers a potential solution to mitigate these adverse effects. However, comprehensive research on their applications in alleviating drought stress, remediating heavy metals, and enhancing crop production is limited. To address these gaps, the optimal ratio for L-GH synthesis using sodium lignosulfonate (L) and γ-polyglutamic acid (γ-PGA) as raw materials was determined through the response surface method (RSM). The synthesis mechanism and possible functional groups and structures of L-GH were identified by Fourier infrared spectroscopy (FTIR) and other characterization techniques. A pot experiment assessed the effects of L-GH (L0=0; L1=0.2 %; and L2=0.5 %) and foliar Se (L0=0; Se=3 mg.L−1) under drought (H=75 % control; HA=45 % field water capacity) on Chinese broccoli growth and the uptake of heavy metals cadmium, copper, zinc (Cd, Cu, Zn). Results indicated that L-GH hydrogel, with a layered porous structure and hydrophilic functional groups, achieved a water absorption rate of 389.17 g.g−1. Under drought and heavy metal stress, L-GH combined with Se effectively reduced the absorption of Cd and Cu. In the L2+Se treatment (0.5 % L-GH + 3 mg.L−1 Se), Cd and Cu contents decreased by 31.06 % and 72.14 %, respectively. Simultaneously, the photosynthetic activity of the plant increased, stress resistance was enhanced, and both growth and biomass accumulation were promoted. Malondialdehyde (MDA) content decreased by 78.82 %, and chlorophyll fluorescence parameters (PSII potential activity Fv/F0 and maximum photochemical efficiency Fv/Fm) increased by 49.92 % and 11.97 %, respectively. Redundancy analysis (RDA) revealed that L-GH could potentially decrease the absorption of heavy metals by enhancing soil moisture (SWC) and pH levels, increasing aggregate stability (WAS) and organic carbon (SOC) content, enhancing plant stress resistance, and promoting growth. In this study, a novel material (L-GH) capable of retaining water and immobilizing heavy metals in soil was successfully developed. The concurrent application of L-GH with Se has been shown to effectively mitigate the combined stresses of drought and heavy metals on the growth of Chinese broccoli. These findings offer valuable insights for the remediation of soil contaminated by both drought and heavy metals.

Data on vermicompost effect on the uptake of cadmium from soil by the roots of radish (Raphanus sativus)

Cadmium is a common environmental heavy metal that is very toxic and carcinogenic for human and other flora and fauna. Therefore, this study is aimed to evaluate the fisibility of vermicompost fertilizer for cadmium uptake from soil by the root of radish (Raphanus sativus). For the purpose of the study, four different ratios of one case control, 1 per 1, 1 per 4, 2 per 4, 3 per 4 vermicompost fertilizer per soil with 0, 50000 and 100000 µg/L cadmium concentrations was evaluated. Cadmium in the samples was measured using an Atomic Absorption Spectroscopy (AAS). The results showed that the minimum uptake of cadmium by the plant was observed for 3 per 4 ratio of fertilizer per soil. In addition, results revealed that highest growth rate of Raphanus sativus roots occurred in maximum ratio of fertilizer per soil usage (3 per 4). This study showed that vermicompost as a organic fertilizer has a good ability to adsorb cadmium metal from soil. Therfore, vermicompost application can be considered as an inexpensive natural adsorbent in arable land contaminated with cadmium.•Heavy metals are very toxic and carcinogenic to human and animals.•Adding organic fertilizer to the soil increases the absorption of heavy metal (cadmium) in the soil and prevents it from entering the food chain.•The relationship between the concentration of cadmium absorbed by the tuber of radish plant and the percentage of vermicompost added to the soil is presented.

Association between heavy metals exposure and risk of attention deficit hyperactivity disorder (ADHD) in children: a systematic review and meta-analysis.

Heavy metals can negatively affect children's neurodevelopment, yet the relationship between heavy metals exposure and attention deficit hyperactivity disorder (ADHD) in children remains unclear. We aimed to examine associations between exposure to five common heavy metals (lead, arsenic, mercury, cadmium, and manganese) with neurodevelopmental toxicity and the risk of ADHD in children. Online databases of PubMed, Web of Science, and Embase were searched before February 29, 2024. A total of 31 studies involving 25,258 children were included in the final analysis. Our findings revealed that lead exposure was positively associated with ADHD risk in children (OR = 1.95, 95% CI: 1.57-2.41) overall, while the associations varied among different WHO regions, with the strongest in the Americas. Sensitivity analyses revealed significant associations between arsenic (OR = 1.53, 95% CI: 1.01-2.32) and manganese (OR = 1.79, 95% CI: 1.28-2.49) exposure and ADHD risk after omitting one study. Arsenic exposure was positively associated with ADHD risk in studies conducted in the Americas and adjusted for environmental smoke exposure. Positive associations between manganese exposure and ADHD risk were also found in several subgroup analyses. No significant associations were found for mercury and cadmium exposure. Dose-response meta-analysis suggested that children with higher blood lead levels exhibited a higher probability of ADHD diagnosis. Lead exposure consistently increases the risk of ADHD in children, while arsenic and manganese exposure may be associated with ADHD under different occasions. More research is required to understand heavy metals' impact on ADHD across varying exposure levels, particularly in less contaminated regions.

In situ deposition of bismuth on pre-anodized screen-printed electrode for sensitive determination of Cd2+ in water and rice with a portable device

Electrochemical detection is favorable for the rapid and sensitive determination of heavy metal cadmium. However, the detection sensitivity needs to be further improved, and a portable, low-cost device is needed for on-site detection. Herein, an in-situ bismuth modified pre-anodized screen-printed carbon electrode (SPCE) was developed for Cd2+ determination by square wave anodic stripping voltammetry (SWASV). The in-situ bismuth modification enhances the enrichment of Cd2+, and together with pre-anodization improve the electron transfer rate of electrode, thus enhancing the detection sensitivity. The electrode modification method combines pre-anodization and in-situ bismuth deposition, which is very easy and effective. Furthermore, a self-made PSoC Stat potentiostat coupled with a stirring device was fabricated for portable and low-cost electrochemical detection. After comprehensive optimization, the developed method can reach a testing time of 3 min, a detection limit of 3.55 μg/L, a linear range of 5–100 μg/L, and a recovery rate of 91.7–107.1% in water and rice samples for Cd2+ determination. Therefore, our method holds great promise for the rapid, sensitive and on-site determination of Cd2+ in food samples.

Toxic effects of cadmium on the growth and predation capacity of the predator Orius sauteri

The heavy metal cadmium (Cd) leads to significant bottom-up effects on food chains of plants, herbivores, and predators in agroecosystems. Through the transfer and accumulation of Cd. In addition to the indirect effects of this cascading effects, predators Orius sauteri fed with artificial diets containing Cd also have a direct effect. We found that O. sauteri fed with sucrose solutions containing Cd at high concentrations of 125 mg/L and 625 mg/L significantly decreased the survival of the 3rd and 5th instar, female, and male adults (except 125 mg/L) of O. sauteri. However, the survival of O. sauteri nymphs was significantly increased when they fed with low concentrations of 1 mg/L, 5 mg/L and 25 mg/L Cd sucrose solutions. Cd stress has differing effects on the LC50 of each age of O. sauteri, the lowest LC50 for male adults (153 mg/L), followed by 3rd instar nymphs (192 mg/L), 5th instar nymphs (289 mg/L) and female adults (383 mg/L). It is interesting that 1 mg/L, 5 mg/L, and 25 mg/L of sucrose solutions containing Cd significantly improved the predation capacity of the nymphs of O. sauteri to the Bemisia tabaci pupa. The predation ability of the male adults of O. sauteri on B. tabaci pupa were significantly improved, but significantly decreased in the female adults when they fed with 125 mg/L and 625 mg/L sucrose solutions containing Cd. This difference needs to be studied in depth in the future, controlling Cd contamination and protecting natural enemies to enhance the biological control of pests.Graphical

Copper leaching from ultrasonically treated milled waste printed circuit boards: investigation of parameters optimization and kinetics.

Waste printed circuit boards (WPCBs) encompass abundant metals (gold, silver, and copper), along with other harmful materials including brominated epoxy resins, plastics, and heavy metals (lead, mercury, and cadmium). Direct burning and landfilling of WPCBs may cause severe health issues and impair the environment. Therefore, sustainable treatment of WPCBs is necessary to recover valuable metals and remove hazardous materials before disposal. The present work investigates the separation of copper-rich metallic fractions from the WPCBs by the combination of hammer milling and ultrasonic irradiation. Initially, discarded mobile phone PCBs are pre-processed and shortened into 1 × 1 cm2. Downscaled WPCBs are fed into the hammer mill to obtain the fine ground powder. The Powdered WPCBs are further processed through ultrasonic treatment to acquire metal-rich fraction. XRD, SEM-EDS, and ICP/AAS analysis revealed that the current technique can efficiently separate the metal-rich fraction without using toxic solvents. Results show the enhancement of copper fraction from 42.73 to 87 wt. % after ultrasonic treatment of WPCBs ground powder. Further, nitric acid leaching has been implemented to metal-rich fractions, and the parameters have been optimized for copper leaching with the assistance of response surface methodology (RSM) of the design of experiments (DOE). Quantitative dissolution (98.96%) of copper occurred using 3.5M nitric acid within 3h at 30°C with 50 GPL pulp density and 500rpm agitation speed. Finally, the kinetics of the leaching process were studied to conform the kinetics model. Moreover, the activation energy for diffusion (19.075kJ/mole) and reaction kinetics model (13.29kJ/mole) has also been calculated. The low energy consumption due to room temperature pre-treatment and effective leaching ensures the industrial feasibility of the proposed process.

Investigation of the Relationship Between Heavy Metals (Cadmium, Arsenic, and Lead) and Metallothionein in Multiple Sclerosis.

Multiple sclerosis (MS) is one of the most common neurological disorders. Metals are important for the maintenance and preservation of homeostasis and dysregulated metal homeostasis has an impact on neurodegeneration. Environmental factors are considered to contribute to MS risk and progression. Heavy metals such as arsenic (As), cadmium (Cd), and lead (Pb) are widely found in the environment and because of their toxic nature, they pose a great danger to human health. Metallothioneins (MTs) play important roles in metal homeostasis and detoxification of heavy metals. The aim of this study was to investigate the relationship between levels of heavy metals (As, Cd, and Pb) andMT levels in MS patients and also to assess the oxidative stress status of patients. Fifty subjects (20 healthy subjects and 30 MS patients) were included. Demographic characteristics of the patients, plasma MT levels, blood Cd, As, and Pb levels, as well as iron (Fe), copper (Cu), and zinc (Zn) levels, were determined. Malondialdehyde (MDA) levels were investigated as a marker of oxidative stress. MT levels were slightly higher in the MS group (p > 0.05). As Cd and Pb levels were significantly higher in the control subjects. MDA levels were significantly higher in MS patients. Our results support the relevance of MT and MDA levels in MS. Further clinical studies with larger cohorts will provide more insights into these factors.

Single and joint bioaccumulation and toxicity of isoproturon and cadmium in green algae (Chlamydomonas reinhardtii)

BackgroundXenobiotics like pesticide isoproturon (IPU) and heavy metal cadmium (Cd) are environmental contaminants posing serious impacts on ecosystem. Understanding their toxic and accumulative processes is crucial to uncover insightful mechanisms and minimize health risks. However, the joint effect of IPU and Cd on microorganisms in aquatic ecosystems remains elusive. In this study, Chlamydomonas reinhardtii was selected as a model unicellular organism to evaluate the ecotoxicological effects of IPU and Cd, focusing on biological responses, bioaccumulation capacity, and environmental adaptation.ResultsThe combined treatment with IPU (0.24 μmol L−1) and/or Cd (20 μmol L−1) for 60 h can induce acute toxicity to C. reinhardtii, reducing chlorophyll and photosynthetic fluorescence, while increasing oxidative damage manifested by lipid membrane peroxides and electrical conductivity. IPU and Cd were accumulated in C. reinhardtii. Interestingly, IPU accumulation in algae was significantly repressed in the presence of Cd, showing a remarkable decrease of 116.7% compared to the IPU treatment alone. Similarly, the Cd concentration in the cells exposed to IPU was reduced by 23.5% compared to Cd treatment alone. Calculation of the bioconcentration factors revealed lower accumulation values of IPU or Cd in algae under Cd+IPU exposure compared to IPU or Cd stress, suggesting an antagonistic interaction between IPU and Cd during absorption by the algae. Furthermore, the activities and transcriptional expression of enzymatic antioxidants such as SOD and APX were significantly induced by Cd stress, whereas the activities of CAT, APX, and PPO significantly increased elevated by IPU.ConclusionsThis study provides compelling evidence of the ecotoxicological effects of combined IPU and cadmium contamination on algae, highlighting the potential of algae for bioremediation of environments contaminated with IPU and cadmium.Graphical

Assessment of the Impact of Heavy Metals on Clarias gariepinus Burchell and Heterobranchus longifilis Fish Species of Omambala River Basin of Anambra State Nigeria

Heavy metals are natural occurring minerals that are found in nature, as deposits in pure and mostly ore form. They are referred to as transition metals due their variable oxidation state, which as a result have made them to develop special properties among other elements in the periodic table. This study aimed to assess the levels of heavy metals (Lead, Chromium, Mercury, Cadmium, Iron, Zinc, Copper and Magnesium) in Clarias gariepinus and Hetrobrancus longifilis collected from the Omambala River. The fish samples were collected by fishermen at the fish landing site. The heavy metal analysis in the two fish species was studied using Atomic Absorbtion Spectrophotometer (AAS) and the instrument was calibrated with standard solutions. The result of this work showed that the highest compositions of heavy metals were: lead (Pb) content in C. gariepinus was 2.69±1.417 mg/l while in H. longifilis was 3.14±1.395 mg/l. However, Chromium content in C. gariepinus was 3.11±0.826 mg/l and in H. longifilis was 4.04±1.073 mg/l. Mercury in C. gariepinus was 3.98±1.903 mg/l and H. longifilis was 4.77±2.283 mg/l. Cadmium in C. gariepinus was 4.90±2.100 mg/l while H. longifilis was 4.83±2.019 mg/l. Moreover, Iron in C. gariepinus was 3.94±1.414 mg/l and H. longifilis was 4.31±2.077 mg/l. Zinc in C. gariepinus was 4.02±1.917 mg/l and H. longifilis was 5.47±2.607 mg/l. Copper in C. gariepinus was 2.62±0.720 mg/l while in H. longifilis was 3.01±0.828 mg/l. Magnesium in C. gariepinus shows 4.66±2.774 mg/l and H.longifilis shows 3.72±1.466 mg/l. The most prevalent heavy metals from the study were Zn, Cd, Hg, Mg, Fe, Cr, Pb, and Cu. It is therefore recommended that further research be made, and awareness created on the high health risk associated with frequent ingestion of these harmful mineral elements found in trace deposits in the Omambala River by the appropriate authority to ascertain their concentrations.

Detection and Distribution of Residues and Additives in Meat and Meat Products in Zenica-Doboj Canton, Bosnia and Herzegovina

Objectives: Many additives are of essential importance for the taste and quality of products, however, many of them pose a danger to human health, and are subject to daily routine quality control of products intended for human consumption. In addition to additives, residues represent a major challenge as possible contaminants of products from the field to the dining table. Methods: Through the research, 85 samples of meat products (salami, sausages, dried meat products) were processed and all were analyzed for the presence of aflatoxin B1 (AFL B1), as well as for chlorides, nitrites and heavy metals (cadmium and lead). Results: The average content of AFL B1 in the meat samples was 0.048 µg/kg (0.019 to 0.105 µg/kg). Chloride content was detected in the range from 0.000 to 9.955 %m/m (average concentration 2.377 %m/m). The average nitrite content was 8.330 mg/kg (min. 0.550 – max. 45.705 mg/kg). Among the 85 processed samples, lead and cadmium were detected in 79 and 29 products (92.94% and 34.11%), with an average of 0.136 and 0.042 mg/kg, respectively. Lead was detected in the range from 0.000 to 3.474 mg/kg, and cadmium from 0.000 to 2.544 mg/kg. Conclusions: The results show the need for continuous monitoring of the amount of additives in meet products on the market, and regular monitoring of residues in products intended for human consumption. It is necessary to stick to proper hygienic practices during the preparation of the product at all stages from the field to the dining table. Keywords: residues, additives, lead, cadmium, public health

Deep-sea microorganisms-driven V5+ and Cd2+ removal from vanadium smelting wastewater: Bacterial screening, performance and mechanism

The disorderly discharge of industrial wastewater containing heavy metals has caused serious water pollution and ecological environmental risks, ultimately threatening human life and health. Biological treatment methods have obvious advantages, but the existing microorganisms exhibit issues such as poor resistance, adaptability, colonization ability, and low activity. However, a wide variety of microorganisms in deep-sea hydrothermal vent areas are tolerant to heavy metals, possessing the potential for efficient treatment of heavy metal wastewater. Based on this, the study obtained a group of deep-sea microbial communities dominated by Burkholderia-Caballeronia-Paraburkholderia through shake flask experiments from the sediments of deep-sea hydrothermal vents, which can simultaneously achieve the synchronous removal of vanadium and cadmium heavy metals through bioreduction, biosorption, and biomineralization. Through SEM-EDS, XRD, XPS, and FT-IR analyses, it was found that V(V) was reduced to V(IV) through a reduction process and subsequently precipitated. Glucose oxidation accelerated this process. Cd(II) underwent biomineralization to form precipitates such as cadmium hydroxide and cadmium carbonate. Functional groups on the microbial cell surface, such as -CH2, C=O, N-H, -COOH, phosphate groups, amino groups, and M-O moieties, participated in the bioadsorption processes of V(V) and Cd(II) heavy metals. Under optimal conditions, namely a temperature of 40 °C, pH value of 7.5, inoculation amount of 10%, salinity of 4%, COD concentration of 600 mg/L, V5+ concentration of 300 mg/L, and Cd2+ concentration of 40 mg/L, the OD600 can reach its highest at 72 h, with the removal efficiency of V5+, Cd2+, and COD in simulated vanadium smelting wastewater reaching 86.32%, 59.13%, and 61.63%, respectively. This study provides theoretical insights and practical evidence for understanding the dynamic changes in microbial community structure under heavy metal stress, as well as the resistance mechanisms of microbial treatment of industrial heavy metal wastewater.

Risk Assessment of Toxic Heavy Metal Exposure through Medicinal Herbs in the Indian State of West Bengal

Background: More than 80% of the world's population uses herbal remedies in some form. Heavy metal contamination and the attendant health risks of Indian herbal medicines are not adequately documented. Objective: This study aimed to investigate the health risks associated with four common heavy metal contaminants, namely lead, arsenic, cadmium, and mercury, present in raw medicinal herbs cultivated or growing wild in the West Bengal state of India. Method: A total of 197 raw herbs obtained from herbal medicine practitioners or wild plant col-lectors from 16 districts spread across 3 geographical zones (south, central, north) of West Bengal were analyzed. In accordance with AOAC specifications, all samples were dried in a hot air oven, ground into a coarse powder, and then processed and analyzed for heavy metals through atomic absorption spectrometry. The mean concentrations were estimated along with standard devia-tions, overall, zone-wise, and according to the botanical part tested. The standardized human health risk indices were calculated from the results. Results: Significant amounts of heavy metals were found in the herb samples analyzed in the order: lead in 150 samples (76.1%), arsenic in 84 (42.6%), cadmium in 77 (39%), and mercury in 47 (23.8%). Central zone samples had the highest concentrations of lead (10.06 μg/g), arsenic (0.62 μg/g), and cadmium (0.54 μg/g), while the greatest amount of mercury (0.08 μg/g) was obtained in herbs from South zone. There were also considerable variations with respect to the source of the botanical part. Lead and cadmium concentrations showed a significant positive cor-relation (r = 0.588). Although risk assessment using standardized measures indicated some risk, the human Hazard Index (HI) was less than 1 for all metals, indicating that it was mostly safe to use the herbs in the short-term. However, the risk of health issues from prolonged use still re-mains. Conclusion: Significant contaminations were identified, but exposure would mostly be within acceptable risk levels at present. However, since risk would be cumulative over time, programs need to be in place to monitor pharmaceutical herb safety, identify local sources of pollution, and take appropriate remedial action.

Geotechnical performance of black cotton clay in the presence of lead and cadmium solutions for geoenvironmental application

ABSTRACT The usage of bentonites and sand–bentonite mixtures as liners has become prevalent due to their low permeability. However, these materials are scarce and prohibitively expensive in India. Black cotton clay (BCC) was chosen as an alternative clay liner for this research due to its abundance in India and its mineralogical composition. Since heavy metals accumulation in municipal landfills is a rising issue with devastating effects on the ecosystem and human health, in this investigation, two heavy metals (lead and cadmium) were intended as permeants at three different concentrations (100, 500, and 1000 ppm) to imitate the impact of heavy metal leachate on BCC. The essential index and engineering properties of BCC were evaluated and compared under these two permeants from the liner perspective. Experimental results revealed that the free swell index, Atterberg limits, swelling and swelling pressures were reduced for a rise in concentration irrespective of metal type. However, this reduction was more with cadmium permeants compared to lead. The measured swelling data was compared with predicted swelling data using a rectangular hyperbola model, and a good correlation was achieved. The hydraulic conductivity (k) and unconfined compressive strength (UCS) values were increased for a rise in concentration with both metal permeants. At 1000 ppm concentration, the k values were raised to 3.5 and 6.7 times, and UCS values were enhanced by 8.3 and 5.5% for lead and cadmium permeants, respectively. At high concentrations, field emission scanning electron microscopy (FESEM) results showed the formation of huge voids and aggregation.

The influence of heavy metals on cytotoxicity in Tilapia zillii

The present study was designed to investigate the cytotoxic effects and bioaccumulation of heavy metals iron (Fe), zinc (Zn), copper (Cu), cadmium (Cd), lead (Pb), manganese (Mn), nickel (Ni), and chromium (Cr) in different parts (muscle, gills, and liver) of Tilapia zillii occurring in polluted drainage canal and fish farm, which is located in Abiece region in front of village number 10, Alexandria governorate, Egypt. Results of water analysis revealed the concentration of Cd, Pb, Mn, Ni, and Cr exceeded the limits defined by the American Public Health Association (APHA) in the polluted drainage canal. In addition, the concentration of Ni elevated to the standard limits of APHA and Cu was not detected in the fish farm. Different types of chromosomal aberrations were recorded (e.g., stickiness, fragmented chromosomes, centromeric gaps, chromatid break, chromatid deletion, and tetraploid). Micronucleus frequency was found to be 5.58 in the polluted drainage canal group and 0.32 in the fish farm group. Other nuclear abnormalities such as blebbed nucleus, segmented nucleus, enucleated erythrocyte, kidney-shaped nucleus, heart-shaped nucleus, polymorphic irregular nuclei, binucleated cell, nuclear fragmented erythrocyte, long nucleus, putative fragmented notched nucleus, lobed nuclei, fused erythrocytes, necrotic erythrocyte, and vacuolated nucleus were recorded. The total of erythrocytes nuclear morphological abnormalities was 70.33% in the polluted drainage canal and 1.78% in the fish farm.