Heavy Metals Research Articles

A Critical Review of Recent Advances in Maize Stress Molecular Biology

With the intensification of global climate change and environmental stress, research on abiotic and biotic stress resistance in maize is particularly important. High temperatures and drought, low temperatures, heavy metals, salinization, and diseases are widespread stress factors that can reduce maize yields and are a focus of maize-breeding research. Molecular biology provides new opportunities for the study of maize and other plants. This article reviews the physiological and biochemical responses of maize to high temperatures and drought, low temperatures, heavy metals, salinization, and diseases, as well as the molecular mechanisms associated with them. Special attention is given to key transcription factors in signal transduction pathways and their roles in regulating maize stress adaptability. In addition, the application of transcriptomics, genome-wide association studies (GWAS), and QTL technology provides new strategies for the identification of molecular markers and genes for maize-stress-resistance traits. Crop genetic improvements through gene editing technologies such as the CRISPR/Cas system provide a new avenue for the development of new stress-resistant varieties. These studies not only help to understand the molecular basis of maize stress responses but also provide important scientific evidence for improving crop tolerance through molecular biological methods.

New Water Treatment Plant Removes Eight Heavy Metals

New Water Treatment Plant Removes Eight Heavy Metals

Microalgae-Assisted Treatment of Wastewater Originating from Varied Sources, Particularly in the Context of Heavy Metals and Antibiotic-Resistant Bacteria

The increasing prevalence of heavy metals and antibiotic-resistant bacteria in wastewater (WW) raises serious environmental and public health concerns. This study investigates the efficiency of the microalgal strain Chlorella vulgaris EV-465 in treating wastewater and evaluates the antibiotic resistance profile of bacterial strains obtained from WW samples. Chlorella vulgaris EV-465 was used to treat four types of wastewater—domestic, municipal, hospital, and industrial wastewater—through 21 days of incubation. The findings demonstrated pH stabilization and significant decreases in nutrients (total nitrogen—TN, total phosphorus—TP), biological oxygen demand (BOD), chemical oxygen demand (COD), heavy metal (HM) concentrations, and bacterial count. Copper (Cu) showed the highest reduction, decreasing by 80% in industrial wastewater within 14 days, while lead (Pb) proved more resistant to removal, with only a 50% decrease by day 21. Additionally, the algae decreased bacterial counts, lowering colony-forming units (Log CFU/mL) from 9.04 to 4.65 in municipal wastewater over the 21-day period. Antibiotic susceptibility tests for isolated bacterial strains revealed high levels of resistance, with seven out of nine bacterial strains exhibiting multidrug resistance. Notably, Enterococcus faecium (PBI08), Acinetobacter baumannii (YBH19), and Pseudomonas aeruginosa (NBH16) displayed resistance to all nine antibiotics tested. Among the tested antibiotics, Ciprofloxacin showed the highest efficacy, with 66% susceptibility of tested bacterial strains. Cluster and phylogenetic analyses showed that the majority of the isolated bacterial strains belonged to the genera Pseudomonas and Escherichia, highlighting their genetic diversity and varied resistance mechanisms.

A Comprehensive Review of Advanced Treatment Technologies for the Enhanced Reuse of Produced Water

Produced water (PW) is considered to be the largest source of industrial wastewater associated with oil and gas extraction operations for industrial production. It is a mixture of organic and inorganic compounds that has high complexity in terms of various characteristics. Globally, the volume of PW is increasing along with the expansion of gas and oil fields, leading to major impacts on the environment. Existing treatment technologies involve partially treating the PW through removing the suspended solids, heavy metals, without removing organic components and re-injecting the water underground using water disposal injection wells. The treatment process consists of a primary treatment unit to remove the particles, followed a secondary biological or chemical processing treatment, while the final treatment stage involves the use of a tertiary treatment unit to improve the water quality and remove the remainder of the undesired components. Moreover, while PW is considered one of the available options to be utilized as a water source, no alternate advanced treatment options on a commercial scale are available at present due to the limitations of existing PW treatment technologies, associated with their maintainability, sustainability, cost, and level of quality improvement. As such, research focused on finding an optimal treatment approach to improve the overall process continues to be conducted, with the aim of reusing the water instead of injecting it underground. This literature review discusses the latest advanced technologies for PW treatment aimed at reusing the full stream capacity of PW and eliminating the need for wastewater disposal via injection. It is concluded that researchers should focus on hybrid treatment technologies in order to remove the pollutants from PW, effectively allowing for its reuse.

Adsorption Properties of Fishbone and Fishbone-Derived Biochar for Cadmium in Aqueous Solution

Cadmium (Cd) contamination in aquatic ecosystems is a serious global environmental issue. Biochar derived from agricultural wastes has recently attracted remarkable attention as it is used as an absorbent in combating heavy metal contamination of water bodies. In the present study, the absorption efficacy of fish bone (FBM) and fishbone-derived biochar prepared at 200 °C, 400 °C, 600 °C, and 800 °C (referred to as B200, B400, B600, and B800, respectively) for the Cd ion (Cd2+) in aqueous solution was investigated. The results showed that high-temperature pyrolysis could optimize the pore structure and specific surface area of FBM, and Cd2+ successfully adsorbed onto FBM and fishbone-derived biochar. High-temperature pyrolysis significantly increased the FBM adsorption capacity for Cd2+ by 49.5–135.1%, with the optimal pyrolysis temperature being 600 °C. Furthermore, the kinetic data of FBM and fishbone-derived biochar for Cd2+ were in better alignment with the pseudo-second-order model, their adsorption isotherms were better in accordance with the Langmuir models, and the thermodynamic analysis showed that the adsorption process was monolayer and favorable adsorption. Moreover, the potential adsorption mechanisms of Cd2+ on FBM and fishbone-derived biochar might be related to pore filling, ion exchange, complexation with oxygen functional groups, and precipitation with the minerals on the biochar surface. Fishbone-derived biochar has significant potential for wastewater treatment and agricultural waste applications.

Chlorella vulgaris as a food substitute: Applications and benefits in the food industry

AbstractChlorella vulgaris, a freshwater microalga, is gaining attention for its potential as a nutritious food source and dietary supplement. This review aims to provide a comprehensive discussion on C. vulgaris, evaluating its viability as a food substitute in the industry by exploring the nutritional value and application of C. vulgaris in the food industry. Rich in protein, lipids, carbohydrates, vitamins, and minerals, Chlorella offers substantial nutritional benefits, positioning it as a valuable food substitute. Its applications in the food industry include incorporation into smoothies, snacks, and supplements, enhancing the nutritional profile of various food products. The health benefits of Chlorella encompass antioxidant activity, immune system support, and detoxification, contributing to overall well‐being. Despite these advantages, the commercialization of Chlorella faces significant challenges. These include variability in antibacterial activity due to strain and growth conditions, high production costs, contamination risks, and sensory issues such as unpleasant taste and smell. Additionally, Chlorella can accumulate heavy metals from its environment, necessitating stringent quality control measures. Future prospects involve improving Chlorella strains through genetic manipulation to enhance nutrient content, developing cost‐effective culture systems, and exploring advanced processing techniques like pulsed electric fields for better digestibility. Addressing sensory issues through flavor‐masking strategies and employing environmental management practices will further support Chlorella's integration into the food industry. Although C. vulgaris shows great potential as a nutritious food ingredient, overcoming existing challenges and optimizing production methods would be crucial for its successful adoption and widespread use.

Assessment of heavy metals contamination/pollution of phosphogypsum waste of the Mdhilla region (Gafsa, southern Tunisia).

Tunisia is currently faced with the extremely delicate problem of managing the millions of tons of phosphogypsum (PG) discharges which is already causing considerable environmental damage. The research carried out in this work is part of a geochemical assessment of the level of heavy metal contamination in phosphogypsum waste from the Mdhilla region (Gafsa, southern Tunisia). The assessment of ETM contamination/pollution is based on the relatively simple principles of measuring concentrations, calculating indices, and comparing them with established standards, which vary according to the nature of the element, its toxicity, and the receiving environment. Six PG samples are taken from the storage heaps right next to the chemical group's plant. Our investigations to assess the level of heavy metals contamination focused on: zinc (Zn), chromium (Cr), copper (Cu), nickel (Ni), and cadmium (Cd). These metallic elements are measured by atomic absorption spectrometry. To achieve our objectives, we calculated several indices, such as the geo-accumulation index (Igeo), the contamination factor (FC), the degree of contamination (DC), and the sediment pollution index (IPS). The index approach enables us to predict the extent of heavy metal pollution in these PG discharges from the Mdhilla region. The Mdhilla region's PG heavy metals contents show the following order of abundance: Zn > Ni > Cr > Cd > Cu. Calculation of contamination/pollution indices reveals in principle polymetallic contamination dominated by three elements: cadmium, nickel, and copper.

Cadmium (Cd) Tolerance and Phytoremediation Potential in Fiber Crops: Research Updates and Future Breeding Efforts

Heavy metal pollution is one of the most devastating abiotic factors, significantly damaging crops and human health. One of the serious problems it causes is a rise in cadmium (Cd) toxicity. Cd is a highly toxic metal with a negative biological role, and it enters plants via the soil–plant system. Cd stress induces a series of disorders in plants’ morphological, physiological, and biochemical processes and initiates the inhibition of seed germination, ultimately resulting in reduced growth. Fiber crops such as kenaf, jute, hemp, cotton, and flax have high industrial importance and often face the issue of Cd toxicity. Various techniques have been introduced to counter the rising threats of Cd toxicity, including reducing Cd content in the soil, mitigating the effects of Cd stress, and genetic improvements in plant tolerance against this stress. For decades, plant breeders have been trying to develop Cd-tolerant fiber crops through the identification and transformation of novel genes. Still, the complex mechanism of Cd tolerance has hindered the progress of genetic breeding. These crops are ideal candidates for the phytoremediation of heavy metals in contaminated soils. Hence, increased Cd uptake, accumulation, and translocation in below-ground parts (roots) and above-ground parts (shoots, leaves, and stems) can help clean agricultural lands for safe use for food crops. Earlier studies indicated that reducing Cd uptake, detoxification, reducing the effects of Cd stress, and developing plant tolerance to these stresses through the identification of novel genes are fruitful approaches. This review aims to highlight the role of some conventional and molecular techniques in reducing the threats of Cd stress in some key fiber crops. Molecular techniques mainly involve QTL mapping and GWAS. However, more focus has been given to the use of transcriptome and TFs analysis to explore the potential genomic regions involved in Cd tolerance in these crops. This review will serve as a source of valuable genetic information on key fiber crops, allowing for further in-depth analyses of Cd tolerance to identify the critical genes for molecular breeding, like genetic engineering and CRISPR/Cas9.

Contrasting pathogen prevalence between tick and dog populations at Chornobyl

Abstract Background The 1986 disaster at the Chornobyl Nuclear Power Plant released massive amounts of radioactive material into the local environment. In addition to radiation, remediation efforts and abandonment of military-industrial complexes contributed to contamination with heavy metals, organics, pesticides and other toxic chemicals. Numerous studies have evaluated the effects of this contamination on the local ecology. However, few studies have reported the effect of this contamination on vector-borne pathogens and their hosts. In this manuscript, we characterize tick-borne pathogen presence at two sample locations within the Chornobyl Exclusion Zone, one at the Nuclear Power Plant (NPP) and another 16 km away in Chornobyl City (CC). Methods Ticks and whole-blood samples were collected from free-breeding dogs captured at the NPP and CC. Endpoint PCR and quantitative PCR were used to identify tick species and to assess the presence of specific tick-borne pathogens, including Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, Babesia spp., Bartonella spp., Francisella tularensis and general Anaplasmataceae. A droplet digital PCR assay was developed for Babesia canis and A. phagocytophilum to evaluate their presence in dogs from the two populations. Pathogen prevalences between the two sample populations were compared by calculating Z-scores. Results Ticks were identified as Ixodes ricinus (n = 102) and Dermacentor reticulatus (n = 4). Overall, 56.9% of I. ricinus ticks were positive for at least one pathogen. A significantly higher prevalence of A. phagocytophilum and B. burgdorferi was found in ticks at the NPP (44.0% and 42.0%, respectively) compared to CC (23.1% and 19.2%, respectively). Babesia spp. (including B. canis and B. caballi) were detected in 8.8% ticks at similar proportions for both populations. Interestingly, we found a significantly lower level of A. phagocytophilum in dogs at the NPP (1.8%) than in dogs at CC (11.7%). In total, 24.3% of dogs were positive for B. canis, evenly distributed across the two populations. Conclusions The results of this study show contrasting pathogen prevalence in both ticks and dogs at the NPP and CC, which may reflect the differential exposures at the two locations. This work adds an important new component to our understanding of the consequences of prolonged exposure to environmental contamination on the wildlife and ecology within the Chornobyl Exclusion Zone. Graphical Abstract

The Bioaccumulation of Potentially Toxic Elements in the Organs of Phragmites australis and Their Application as Indicators of Pollution (Bug River, Poland)

The bioaccumulation of potentially toxic elements (PTEs) in aquatic plants is critical in assessing the quality of aquatic environments and the risks associated with anthropogenic activities. This research involved using Phragmites australis as a bioindicator in a comprehensive assessment of the spatial variation in pollution within the Bug River catchment, employing advanced statistical methods to identify pollution sources. The study aimed to investigate the bioaccumulation of PTEs in different parts of the P. australis plant and to evaluate their suitability as bioindicators of contamination. Plant samples were collected from 32 locations in the Bug River catchment, and the concentrations of metals such as Cd, Pb, Cr, Ni, Zn, Cu, Fe, and Mn were determined by atomic absorption spectrometry. The results indicated that PTE accumulation was highest in the roots, underscoring their crucial role in monitoring metal concentrations. Metal concentrations differed based on land use within the catchment area, with the highest levels observed in urbanized regions, highlighting the significant impact of human activities like wastewater discharge and transport emissions. The highest concentrations were observed for Fe, Mn, and Zn, while Cd concentrations were notably elevated in agricultural areas. The analyses confirmed that P. australis serves as an effective bioindicator of heavy metal contamination and can be employed in long-term biomonitoring programs.

Genome-wide identification and characterization of bZIP gene family explore the responses of PsebZIP44 and PsebZIP46 in Pseudoroegneria libanotica under drought stress.

The fundamental leucine zipper (bZIP) genes play a crucial role as transcriptional coactivators in plants. Pseudoroegneria libanotica served as the maternal contributor to several species within the tribe Triticeae (Poaceae), exhibiting commendable resilience to various stressors. Consequently, bZIP genes of Pseudoroegneria libanotica response to abiotic stresses was important for further understanding of stress tolerance studies in Triticeae. A total of 108 PsebZIPs were identified in this study, and they were divided into 10 subgroups. PsebZIPs were found to be extensively involved in the biological activities within P. libanotica. The RNA-seq results revealed differential responses of PsebZIPs to drought stress in both aerial and root tissues. PsebZIP44 and PsebZIP46 were regarded as potential genes capable of responding to abiotic stress, and their varying degrees of responsiveness to drought, salinity, heavy metals, heat, and oxidative stress have been demonstrated in yeast. Homologous proteins with intact bZIP gene structures of PsebZIP44 or PsebZIP46 have not been identified in wheat. The current investigation not only provides a fundamental basis for further probing into the biological functions of PsebZIPs within P. libanotica but also reveals previously undiscovered potential genes with the ability to respond to abiotic stress. They could contribute to improving the genetic constitution of Triticeae crops, including wheat.

Food Safety in Developing Countries: Common Foodborne and Waterborne Illnesses, Regulations, Organizational Structure, and Challenges of Food Safety in the Context of Nepal

ABSTRACTFood safety presents a global challenge, contributing to 600 million cases of foodborne diseases and 420,000 fatalities annually worldwide. In developing countries, such as Nepal, addressing food safety is particularly intricate and arduous because of the prevalent issues of food insecurity, poverty, illiteracy, and regulatory hurdles. The objectives of this comprehensive review are to evaluate the prevalent foodborne and waterborne illnesses, examine the existing regulations and institutional frameworks, and identify the challenges associated with food safety in Nepal. Additionally, this review aims to propose strategies to enhance food safety measures in the country. An electronic search was conducted using relevant keywords to include articles and literature pertinent to the topic. Common foodborne illnesses in Nepal include cholera, typhoid fever, hepatitis, worm infections, and poisoning from mushrooms, heavy metals, and pesticides. While existing rules, regulations, and government infrastructure exist, they often face limitations in effectively addressing these multifaceted challenges. Food safety in developing countries, such as Nepal, faces several challenges, including inadequate regulatory frameworks, limited surveillance and monitoring, rural–urban disparities, and high incidences of foodborne illness. Additional issues stem from weak law enforcement, poor food safety practices, limited infrastructure, informal sector challenges, cross‐border trade, limited access to clean water, and the impacts of climate change. A multisectoral One Health approach involving collaboration among government agencies, food industry stakeholders, consumers, and civil society organizations is imperative to enhance food safety in developing countries such as Nepal.

To the Studies on Pollution of Under Ground Water Mau City

The study focuses on the environmental evaluation and classification of the Mau City area, located in the eastern part of Uttar Pradesh, India. The investigation covers an area of approximately 20 km2 and includes a diverse population in terms of socio- economic, cultural, and geographical characteristics. The population data reveals significant growth, with a population increase from 168,716 in 1991 to 2,205,968 in 2011. Animal populations, including cattle and poultry, have also shown an increasing trend from 2018 to 2020. Fertilizer usage data between 2017 and 2020 indicates fluctuations in the consumption of nitrogen, phosphorus, and potassium, demonstrating potential agricultural impacts on the environment. Water quality analysis is a major part of this study, employing various methods to determine salinity, dissolved oxygen, biological oxygen demand (BOD), and chemical oxygen demand (COD). Salinity was measured through titration with silver nitrate, while oxygen levels were analyzed using different methods, including dissolved oxygen (DO) analysis. Results indicate variations in water quality across different sampling sites (S1-S6), with key parameters such as pH, turbidity, temperature, and bacterial contamination being recorded monthly for the years 2019 and 2020.The research also involves the collection and analysis of water samples using various devices, including water samplers, bottom samplers, and biological samplers. Methods such as the EDTA method for water hardness, the gravimetric method for sulfate determination, and the colorimetric analysis for iron and chromium concentrations were utilized to evaluate the pollutants in the water. The study provides critical insights into water quality degradation, highlighting the presence of various pollutants, including nitrates, sulfates, and heavy metals like chromium, copper, and iron.

Sustainable Combination of Waste with Waste: Utilization of Biomass to Recover Critical Metals from Spent Lithium ion Batteries

The generation of e‐waste from lithium ion batteries (LIBs) is rapidly increasing due to the rising utilization of LIBs in portable electronics, and electric vehicles, with an average life span of 3‐5 years. The disposal of spent LIBs is a major environmental concern due to the presence of high percentages of toxic heavy metals and corrosive electrolytes. Efficient and sustainable recycling of spent LIBs has become immensely important, both environmentally and from a circular economy perspective, as LIBs serve as secondary sources of critical metals needed for renewable energy conversion and storage systems. We provide a concise review of metal recovery from spent LIBs using waste biomass in a green and sustainable approach for resource generation, in addition to the valorization of waste biomass. Biomass is used to recover metals from spent LIBs, acting as lixivient, reductant, and as absorbent. We have also discussed a reverse strategy utilizing ‘black mass’ from spent LIBs as catalyst for biomass conversion to value‐added products. The concept of “circular economy” is highlighted in a “killing two birds with one stone” approach through the utilization of biomass for the recovery of metals from spent LIBs and vice versa.

Physicochemical Investigations of Textile Wastewater and Process Parameter Optimization for Bio-decolorization of Congo Red Dye by Pseudomonas aeruginosa MT-2 Strain

Pollution caused by dyes is a major environmental threat, posing adverse impacts on humans, animals, and plants. Therefore, the remediation of such pollutants is essential to protect the environment. This study aimed to conduct physicochemical and bacteriological analyses of textile wastewater to isolate and identify potential native bacterial strains for the decolorization of Congo red dye. Physical and nutritional process parameters were optimized to achieve maximum decolorization. The biological and chemical oxygen demands of the analyzed textile waste water were found to be above the recommended limits. In this study, 19 Congo red -decolorizing bacteria were isolated, with one bacterial culture capable of growing at a higher dye concentration of 300 mg/L. This bacterium was characterized biochemically and genetically (using 16S rRNA sequencing) and identified as the Pseudomonas aeruginosa MT-2 strain. A maximum decolorization of 94.0% was achieved at an initial dye concentration of 150 mg/L, 35°C, and pH 8.0 under static conditions. The bacterial culture also showed resistance to heavy metals such as arsenic, lead, and chromium. The biodegradation of Congo red dye was confirmed through UV-vis spectral analysis and Fourier transform infrared spectrophotometry. The findings of this study demonstrate the high remediation potential of the MT-2 strain, making it suitable for possible use in dye biodecolorization at contaminated sites.

Assessing natural radioactivity risks and heavy metals pollution in Al-Lisi volcanic mountain, Dhamar city, Yemen

Assessing natural radioactivity risks and heavy metals pollution in Al-Lisi volcanic mountain, Dhamar city, Yemen

A review of hydroxyapatite synthesis for heavy metal adsorption assisted by machine learning.

Heavy metals (HMs) represent a persistent and significant threat to aquatic ecosystems. Hydroxyapatite (HAp) has emerged as a utilized material in the remediation of environmental HMs, owing to its exceptionally high porosity, expansive surface area, and the presence of three-dimensional ordered channels. An in-depth study of the synthesis strategy of HAp and its adsorption properties can help reduce the cost of remediating HMs in aquatic environments and alleviate the water shortage. In this paper, we reviewed 466 works of literature on the adsorption of heavy metals by HAp based on the Web of Science database between 2013 and 2023 that focused on the adsorption of heavy metals by HAp. We meticulously synthesized the findings related to the synthesis conditions-namely precipitation, hydrothermal, and calcination-as well as the characterization parameters and the adsorption capacity of HAp for heavy metals such as Pb2+, Cd2+, Cu2+, Zn2+, and Ni2+. Synthesizing advanced materials by reducing the number of experiments is essential to accelerate material development. Machine learning (ML) holds significant promise in material discovery and performance enhancement. We have consolidated the qualitative and quantitative relationships between HAp synthesis conditions, characterization parameters, and heavy metal adsorption capacity across previous studies, utilizing both the Statistical Package for Social Sciences (SPSS) and ML techniques. Building on the most recognized heavy metal adsorption mechanisms, we have evaluated the influence of characterization parameters on adsorption performance. We have outlined the optimal synthetic conditions for enhancing the adsorption of Pb2+, Cd2+, Cu2+, Zn2+, and Ni2+ through precipitation, hydrothermal, and calcination methods, offering a practical guide for the targeted synthesis of HAp tailored to specific heavy metal adsorption capacities.

Heavy Metal Toxicity and its Treatment

Abstract Heavy metals are ubiquitous environmental contaminants that are capable of inducing a broad range of physiological, biochemical and behavioural dysfunctions. Heavy metal poisoning remains a persistent public health problem in Malaysia and throughout the world. Exposure to toxic metals and compounds containing them through inhalation, ingestion or skin contact may cause various pathophysiological conditions, and the nervous system is the most susceptible organ system to this exposure causing a condition known as heavy metal-mediated neurotoxicity. This review summarises the current understanding of the mechanisms by which arsenic, lead and mercury induce heavy metal-mediated neurotoxicity. These heavy metals cause toxic manifestations in the nervous system primarily through the presence of excessive pro-oxidants and depletion of antioxidants, causing an imbalance homeostasis also described as oxidative stress. In addition, this article also reviews previous common chelation treatments and emerging antioxidant treatments since antioxidants have become the current interest in the prevention and treatment of these heavy metal-mediated toxicities.

Distribution of heavy metals in the sediments of Ganga River basin: source identification and risk assessment.

Sediment serves as a heavy metal store in the riverine system and provides information about the river's health. To understand the distribution of heavy metal content in the Ganga River basin (GRB), a total of 25-bed sediment and suspended particulate matter (SPM) samples were collected from 25 locations in December 2019. Bed sediment samples were analyzed for different physio-chemical parameters, along with heavy metals. Due to insufficient quantity of SPM, the samples were not analyzed for any physio-chemical parameter. The metal concentrations in bed sediments were found to be as follows: Co (6-20mg/kg), Cr (34-108mg/kg), Ni (6-46mg/kg), Cu (14-210mg/kg), and Zn (30-264mg/kg) and in SPM, the concentrations were Co (BDL-50mg/kg), Cr (10-168mg/kg), Ni (BDL-88mg/kg), Cu (26-80mg/kg), and Zn (44-1186mg/kg). In bed sediment, a strong correlation of 0.86 and 0.93 was found between Ni and Cr, and Cu and Zn respectively and no significant correlation exists between organic carbon and metals except Co. In SPM, a low to moderate correlation was found between all the metals except Zn. The risk indices show adverse effects at Pragayraj, Fulhar, and Banshberia. Two major clusters were formed in Hierarchal Cluster Analysis (HCA) among the sample points in SPM and bed sediment. This study concludes that the Ganga River at Prayagraj, Banshberia, and Fulhar River is predominately polluted with Cu and Zn, possibly posing an ecological risk. These results can help policymakers in implementing measures to control metal pollution in the Ganga River and its tributaries.

Evaluating the Effects of Heavy Metals on Seminal Fluid Anti Oxidants Status and Semen Parameters among Males with Infertility at Tertiary Health Centre in Nigeria

Abstract Introduction: There are evidences of a reduction in male fertility potential globally. This, coupled with the limitation of the gold standard investigative tool of male infertility, has become necessary that focus should be on elucidating the aetiopathogenic causes of male fertility. This includes the impact of environmental toxic products such as levels of heavy metals that have been proposed to impact both the sperm quality and seminal antioxidant status. The study assessed how the seminal concentrations of specific heavy metals such as cadmium, lead and Iron affect the seminal fluid analysis (SFA) parameters and seminal antioxidant status of males exhibiting abnormal parameters of sperm, analysing infertile male patients consecutively in a cross-sectional manner, with at least one abnormal SFA parameter, at a tertiary health centre. Materials and Methods: One hundred and thirty consenting males who have one or several anomalies with sperm characteristics were selected as subjects. Semen samples were collected, processed and centrifuged. The supernatants were analysed for the heavy metals using Buck Scientific 210/211VGP Flame Atomic Absorption Spectrophotometers 220GF Graphite Furnace and 220AS Autosampler and seminal Vitamins C and E, using spectrophotometric method and glutathione peroxidase, whereas catalase was analysed using ELISA method. Results: Subjects’ seminal levels of Cd, Fe and Pb were notably greater than those of controls, respectively. In addition, individuals’ levels of seminal antioxidants were noticeably lower than controls. Seminal antioxidant status and Seminal Cd, Fe and Pb were positive and negative significantly correlated with sperm count and active motility, respectively. Conclusion: Laboratory quantification of the seminal concentrations of these heavy metals in the evaluation of males with infertility, especially those still regarded as idiopathic, because of limitations of investigative tools and biomarkers, will be of clinical utility, in both the management and prevention of sperm quality deterioration.