Environmental Pollution Research Articles

Lycopene in male infertility.

Male infertility is a major concern around the world, and efforts to find effective therapies to improve reproductive results are continuing. Factors such as genetics, hormonal disorders, lifestyle, and environmental pollutants have been mentioned as the pathoetiology of male infertility. The treatment of male infertility is far from optimal despite the recent signs of progress provided by assisted reproductive technology. Therefore, many efforts are being made to improve the therapeutical approaches to male infertility, which generally target the factors involved in the pathophysiology of the disease. Lycopene is a naturally occurring pigment belonging to the carotenoid family, which imparts a vibrant red color to various fruits and vegetables. It is widely assumed that lycopene may be an optimal option for the improvement of male fertility, however, the verification its therapeutic potential in male infertility has not been comprehensively reviewed. The study discusses the ability of lycopene to improve semen parameters, including sperm morphology, and motility which are important determinants of male reproductive health. Moreover, lycopene's capacity to regulate sex hormones, such as testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which play crucial roles in sperm production and maturation is explained. Additionally, lycopene effects on specific signaling pathways involved in male fertility, including prokineticin-2 (PROK2) and PI3K/Akt pathways, that influence sperm function are clarified. Furthermore, the impacts of lycopene as a potent antioxidant in defending against oxidative stress, a leading cause of male infertility, are presented. Overall, the results indicate that lycopene may have beneficial effects on improving male fertility by increasing sperm parameters, modulating sex hormones and signaling pathways, and providing antioxidant protection. Due to limited reports, additional clinical data is required to confirm the positive effects of lycopene on male fertility in humans.

Titanium Mxene: A Promising Material for Next‐Generation Optical Biosensors and Machine Learning Integration

AbstractNano biosensors based on MXenes have been emerging as a promising tool in the detection of biomarkers, for the discrimination of diseases and in the detection of environmental pollutants. Their potential in sensing applications has also drawn a lot of attention to their unique qualities such as their high conductivity, huge surface area, outstanding hydrophilicity, biocompatibility, and simplicity of surface functionalization. The development of scalable synthesis techniques is essential to the large‐scale manufacturing and broad application of MXene‐based sensors. Furthermore, the stability of the MXene layers in diverse environmental circumstances continues to be a difficulty for their practical application. To increase the dependability and precision of MXene‐based sensors, their selectivity must be increased through functionalization and tuning. With innovative technologies like machine learning, MXene biosensor is now taken advantage of new opportunities. Personalized healthcare solutions, remote data analysis, and real‐time monitoring are all possible when MXene sensors and AI algorithms work together. Herein, the optical properties, synthesis approaches, role of MXene biosensors in machine learning, its significant challenges and future prospects of MXene‐based nano(bio)sensors are deliberated.

Hyperspectral Imaging for Detecting Plastic Debris on Shoreline Sands to Support Recycling

Environmental pollution from plastic debris is raising concerns not only for the vulnerability of marine species to ingestion but also for potential human health hazards posed by small particles, known as microplastics. In this context, marine areas suffer from a lack of constant shoreline cleanups to remove accumulated debris, preventing their degradation and fragmentation. To establish optimal strategies for streamlining plastic recovery and recycling operations, it is important to have a system for recognizing plastic debris on the beach and, more specifically, for identifying the type of polymer and mapping (e.g., topologically assessing) the distribution of plastic debris on shoreline sands. This study aims to provide an operative tool finalized to perform an in situ detection, analysis, and characterization of plastic debris present in the coastal environment (i.e., beaches), adopting a near-infrared (NIR)-based hyperspectral imaging (HSI) approach. In more detail, the possibility of identifying and classifying polymers of plastic debris by NIR-HSI in three different areas along the Pontine coastline of the Lazio region (Latina, Italy) was investigated. The study focused on three distinct beaches (i.e., Foce Verde, Capo Portiere, and Sabaudia), each characterized by a different type of sand. For each location, the adopted approach allowed for the systematic classification of the various types of plastic waste found. Three Partial Least Squares Discriminant Analysis (PLS-DA) classification models were developed using a cascade detection strategy. The first model was designed to distinguish plastics from other materials in sand samples, the second to detect plastic particles in the sand, and the third to classify the type of polymer composing each identified plastic particle. Obtained results showed that, on the one hand, plastics were correctly detected from sand and other materials (i.e., sensitivity = 0.892–1.000 and specificity = 0.909–0.996), and on the other, the recognition of polymer type was satisfactory, according to the performance statistical parameters (i.e., sensitivity = 1.000 and specificity = 0.991–1.000). This research highlights the potential of the NIR-HSI approach as a reliable, non-invasive method for plastic debris monitoring and polymer classification. Its scalability and adaptability suggest possible future integration into mobile systems, enabling large-scale monitoring and efficient debris management.

Natural Low-Melting Mixture Solvents for Green Recovery of Spent All-Solid-State Sodium-Ion Batteries with Superior Efficiency over Lithium-Ion Batteries.

Spent all-solid-state sodium-ion batteries (ASIBs) containing toxic and precious metal would be produced significantly and lead to resource waste and environmental pollution as the wide application of ASIBs in the near future. Therefore, it is necessary to develop green strategy for recovery of ASIBs. Here, we propose a safe, mild and green strategy to recover toxic and precious metals from cathode/solid electrolyte of ASIBs by using natural low-melting mixture solvents (LoMMSs) with high selectivity and high leaching efficiency. Natural LoMMSs are abundant, natural available, cheap, non-flammable, biodegradable and biocompatible. Results show that natural LoMMSs could leach nearly 100% Na and achieve superhigh Na/Zr selectivity of up to 58 from ASIBs at mild temperature, outperforming the recycling efficiency and selectivity of lithium-ion batteries cathode. More importantly, we find that water could be used as a green and low-cost anti-solvent to precipitate the extracted metal from the leachate with low-energy consumption at room temperature. This work provides a cost-effective, energy-saving, mild, green strategy for the recovery of cathode/solid electrolyte from spent ASIBs with high safety and high selectivity.

Synthesis and Characterization of g-C3N4 Modified CoMoO4 Heterojunction with Enhanced Photocatalytic Performance for Levofloxacin Degradation under Visible Light Irradiation

In the current era, environmental pollution, particularly in water bodies, amid the backdrop of dwindling freshwater resources, stands as a pressing concern necessitating attention from both authorities and scientists. To address the issue of pollutant removal from water sources, various methodologies have been proposed, among which advanced oxidation techniques utilizing photocatalysts have garnered widespread interest due to their promising potential. CoMoO4/g-C3N4 photocatalysts can be readily synthesized via the hydrothermal method and subsequent calcination of urea under carefully controlled hydrothermal conditions, ensuring optimal synthesis outcomes. Characterization analyses employing XRD, SEM, EDX, and FT-IR techniques confirm the successful synthesis of CoMoO4/g-C3N4, featuring bandgap energies conducive to photocatalytic activity under visible light irradiation (2.45 – 2.56 eV). In this research, CoMoO4/g-C3N4 catalysts were deployed for Levofloxacin photodegradation under visible light. Thus, the findings highlight the high efficiency of 7% CoMoO4/g-C3N4 photocatalysts in degrading Levofloxacin under optimal conditions, offering a promising approach for the remediation of pharmaceutical pollutants in water.

Nanotechnology for sustainability of agriculture and environment: Green synthesis and application of nanoparticles – A review

Moreover, with the continuous population increase worldwide, there is more demand of food and other daily necessities, which require double agriculture production to provide adequate food for humanity from the same available natural resources. Therefore, looking for new techniques to combat various challenges is instantly needed to sustain crop production and provide enough food for humanity. The use of nano-technology in agriculture field represents an important tool for consistent production of agriculture crops and assists farmers with new practice management systems such as precision agriculture systems, the aim of which is to increase productivity and reduce expenses. Nanotechnology plays an important role in altering agriculture food production. The particles ranging from 1 to 100 nm are accounted as nanoparticles, which usually have high surface energy, big surface area and quantum quarantine. Most notably, nanoparticles increase crop yield by increasing the effectiveness of agricultural inputs to enable site-targeted, controlled nutrient delivery, assuring the least amounts of agro-inputs needed. Additionally, the main aim in agricultural production is to facilitate plants' faster adaptation to the increasingly severe climate change factors, such as high temperatures, low water availability, salinity, alkalinity and environmental pollution with heavy metals, without jeopardizing the delicate ecosystems that are currently in place. This review illustrates the effect of numerous nanoparticles on diverse plants of many concentrations, sizes and shapes. The molecular and genetic response to NPs, their method of action and their interactions with biomolecules should be the main areas of study in the future.

​Quantitative assessment of heavy metal concentrations, pollution levels, and sources apportionment in one of China's top 10 most livable cities.

Urban topsoil is not only an essential part of the urban ecosystem, but also a powerful carrier of pollutants in the urban environment. In this paper, 130 topsoil samples from urban area of Xinyang in central-eastern China were selected, the aim is to quantitatively investigate the concentrations, pollution levels, and sources apportionment of 8 heavy metals (HMs, encompassing arsenic (As), cobalt (Co), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni), vanadium (V), and zinc (Zn)) via geochemical method. The main conclusions are as follows. (1) The eight HMs in the topsoil have been artificially enriched to varying degrees, which are lower than the street dust levels sampled in pairs. (2) Cu, Zn, and Pb were significantly contaminated, and As, Co, Ni, Cr, and V were relatively low levels of contamination. Overall, comprehensive pollution levels were particularly severe, with 30.0%, 39.2%, and 30.8% for slight, moderate, and serious pollution, respectively. (3) Co, Ni, V, and Cr predominantly originated from natural sources, the percentage contribution of which is 6.3%; Pb, As, Cu, and Zn were predominantly derived from traffic-derived sources, with a percentage contribution of 93.7%. Thus, the first-order source of HMs in the topsoil originates from traffic-induced activities, similar to the case of street dust. Our findings can be beneficial in providing local governments with a reference to formulate environmental pollution controls, and also provide a case study for environmental pollution control in the other livable cities in China.

Green Synthesis of Quercetin-Coated Ecofriendly Zirconium Oxide Nanoparticles and Evaluating its in vitro Biological Activities

The development of nanomaterials using green synthesis methods is gaining attention due to their potential to reduce environmental pollution and health risks associated with traditional chemical synthesis methods. Among the various transition metals, zirconia has gained significant interest as filling materials and implants in dentistry due to its excellent mechanical and chemical properties. In this study, we developed ecofriendly zirconium oxide nanoparticles using Biancaea sappan extract as a capping agent and then functionalized them with Quercetin. Further, their anti-inflammatory property and hemocompatibility were evaluated to target their application as filling materials. The biogenic zirconium oxide nanoparticles (B-ZrO2NPs) and quercetin functionalized biogenic zirconium oxide nanoparticles (BQZN) were characterized by UV–Vis Spectroscopy (UV–Vis), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy X-ray analysis (EDX). B-ZrO2NPs showed maximum absorbance at 267[Formula: see text]nm and 383[Formula: see text]nm. FTIR showed characteristic stretching at 3381[Formula: see text]cm[Formula: see text], confirming the O–H group in the extract and Quercetin used for BQZN formation. The FTIR spectra of BQZN displayed the presence of the characteristic peaks observed in the spectra of B-ZrO2NPs and Quercetin. The broad XRD pattern confirmed the amorphous nature of the zirconia. SEM revealed the spherical morphology of B-ZrO2NPs and BQZN with a size range of around 90[Formula: see text]nm and 120[Formula: see text]nm, respectively. EDAX of BQZN revealed the presence of 45.7[Formula: see text]wt.% Zr, 32.9% oxygen and 21.4% of carbon. In vitro bioactivity studies revealed that BQZN exhibited significant anti-inflammatory activity, as evidenced by the inhibition of protein denaturation. The nanoparticles were also demonstrated for their hemocompatibility with erythrocytes. These findings highlight the potential of BQZN as a promising hemocompatible dental filling with significant anti-inflammatory properties. Further in-depth in vivo studies are required to fully understand their efficacy and toxicity.

Outlook for Sustainable Utilization of Agricultural Waste and Biomass Fuel and Materials Production

The reasonable and effective treatment and utilization of agricultural production waste is an effective way to deal with energy depletion and climate change. Agricultural waste, including crop straw, livestock manure, agricultural film, pesticide packaging, the waste if improperly handled, can lead to soil, water and air pollution, like remains in agricultural land contains various chemical elements of crop straw and livestock manure, if improperly handled will cause irreversible of soil erosion and pollution. Through resource utilization, these wastes can be converted into organic fertilizers, bioenergy, feed or other valuable products, thus reducing environmental pollution, improving the efficiency of resource utilization, and promoting the sustainable development of agriculture. This study will discuss the technical progress of the treatment mode of agricultural waste in the current technical field, and find out the shortcomings and challenges of the existing technology. China, India, America, Japan, Thailand and many other countries are stepping up their research on biomass energy. The development and utilization of agricultural biomass have a strong competitiveness in the energy market.

What immunology has to say about pesticide safety

The use of pesticides has enabled the development of contemporary industrial agriculture and significantly increased crop yields. However, they are also considered a source of environmental pollution and a potential hazard to human health. Despite national agencies and the scientific community analyzing pesticide safety, immunotoxicity assays are often not required, poorly designed, or underestimated. Epidemiological evidence indicates that pesticide exposure increases the risk of developing cancer. Therefore, pesticides may not only act as carcinogens per se but also as immunosuppressive agents that create a permissive context for tumor development. Given recent evidence demonstrating the critical role of the immune response in cancer progression, we will highlight the necessity of assessing the potential impacts of pesticides on the immune response, particularly on tumor immunosurveillance. In this Perspective article, we will focus on the need to critically review fundamental aspects of toxicological studies conducted on pesticides to provide a clearer understanding of the risks associated with exposure to these compounds to human health.

China's Low-carbon Energy Transformation: Development of Renewable Energy

In recent years, as the world's population continues to increase, it has brought a series of pollution problems, which causes global warming intensified. In order to solve the problem of climate warming, the development trend of low carbon and environmental protection is gradually becoming the keynote of global social and economic development. At the same time, due to the excessive reliance on energy consumption for the development of China's economy in the past, the problems of energy shortage and environmental degradation have become more and more serious in China in recent years. Therefore, the carbon emission reduction index has become one of the important assessment indicators for the development of China's economic quality and an unavoidable key task for economic development. Energy is the basis of economic and social development, in the process of economic development, China will inevitably encounter energy shortages, environmental pollution problems, the development of renewable energy has become a general trend, the transformation and optimization of the traditional energy structure is an effective way to achieve this goal and an important means. This paper analyzes and puts forward suggestions on the current situation of China's energy transition, factors affecting energy transition and future development trends through the literature review method and comparative analysis method.

Two Birds With One Stone: A Novel Nanocomposite Combining Silicon Nanoparticles and Carbon-Doped Titania as the Fluorescence Probe and Visible Light Photocatalyst for Simultaneous Detection and Removal of Oxytetracycline.

The monitoring and removal of environmental pollutants are vital for the sustainable development of society. Herein, a novel nanocomposite combining silicon nanoparticles and carbon-doped titania, C-TiO2/SiNPs, is designed as a fluorescence probe and visible-light photocatalyst to simultaneously monitor and degrade oxytetracycline (OTC). C-TiO2/SiNPs emit blue fluorescence, which can be quenched by OTC through inner filter effect. Meanwhile, green fluorescence is turned on upon OTC additionby aggregation-induced emission. Thus, C-TiO2/SiNPs successfully act as a fluorescence colorimetric probe for quantitation and semi-quantitation of OTC. Additionally, C-TiO2/SiNPs showadorable visible-light photocatalytic activity toward OTC, achieving a removal rate of 93.3% in 30min. This process is driven by the superoxide radicals, holes and hydroxyl radicals produced by C-TiO2/SiNPs under visible light irradiation. The total toxicities obviously reduce after OTC is degraded by C-TiO2/SiNPs. The concentration during the OTC degradation can be estimated by naked eyes through the change of fluorescence color, but also precisely quantified by a fluorometer. This study innovatively develops a one-stone-two-birds strategy to achieve simultaneous degradation and in situ real-time detection of OTC, paving a promising paradigm for the highly efficient monitoring and removal of residual drugs.

Sustainable colour, sulfate and phosphate removal from vegetable oil refinery wastewater using snail shell waste extracted-chitin-chitosan: Equilibrium studies and toxicity assessment of used adsorbents

Direct discharged of vegetable oil refinery wastewater without treatment can cause severe environmental pollution, corrosion and clogging of pipes. This work is aimed at investigating the use of snail shell extracted chitin and chitosan fortified with alum in removing colour, sulfate and phosphate from vegetable oil refinery waste water, monitoring the pH, and testing the toxicity of the used materials on the growth performance of maize. Chitin and chitosan with good adsorbent properties were produced from snail shells. The spent chitin/alum and chitosan/alum were recycled and their toxicities on the growth performance of maize tested. The studied wastewater had pH of 10.40, sulfate and phosphate concentrations of 3100 and 1561.3 mg/L respectively. Maximum removal capacities for sulfate and phosphate of 842.54 and 728.07 mg/g were respectively obtained for chitin, and respectively 934.97 and 728.00 mg/L for chitosan against colour removal of 0.96 and 0.95 Absorbance/g respectively on chitin and chitosan. Nearly 100% of colour and phosphate were removed by chitin and chitosan systems for all tested parameters against a maximum of 84% for sulfate by chitosan at pH 10 and 80% for chitin at pH 4. From Pseudo-second order kinetics, phosphate and sulfate removal were faster on chitin than chitosan while colour removal was faster on chitosan than chitin. Recycled adsorbents enhanced maize germination and survival than the control where they were absent. Tested adsorbents are effective in improving quality of studied effluent, requiring no electricity and can be used as fertilizers, ensuring clean environment and generation of more revenue

Environmental Pollution and Extraction Methods of Extracellular Antibiotic Resistance Genes in Water

Antibiotics are widely used to treat diseases such as bacterial infections. However, the abuse of antibiotics has led to the spread of antibiotic resistant bacteria and intracellular and extracellular antibiotic resistance genes, making China one of the countries with the highest incidence of antibiotic resistance and thus threatening public health. Extracellular antibiotic resistance genes, as one of the novel environmental pollutants, could exist in water for a long time and could be transmitted between different bacteria through horizontal gene transfer, resulting in the spread of antibiotic resistance. At present, due to the limitation of enrichment and recovery methods, the in-depth studies of extracellular antibiotic resistance genes in water have been rarely reported. Thus, it is impossible to carry out effective supervision and risk assessments. Based on literature analysis and investigation, the pollution sources, current situations, and characteristics of extracellular antibiotic resistance genes in water are expounded. Meanwhile, the advantages and disadvantages of their enrichment and recovery methods are compared and analyzed and the enrichment and recovery methods are verified and discussed through practical cases. These provide theoretical reference for studies such as examining extracellular antibiotic resistance genes in water on their transmission and provide a technical basis for antibiotic resistance control and health risk assessments of extracellular antibiotic resistance genes.

Based on AHP, The Ecological Environment of Fenhe River Basin Is Evaluated

he evaluation of the ecological quality of the Fenhe River Basin is of great significance for the high-quality development of the Yellow River Basin and Shanxi Province. In this paper, the analytic hierarchy process (AHP) is used to evaluate the ecological environment of Fenhe River Basin. Firstly, based on the relevant research literature, the ecological environment evaluation index is determined, and the influencing factors of the evaluation index are determined. Secondly, the weight of different influencing factors is determined based on AHP method, and the weight of evaluation index is obtained. Finally, the ecological environment of Fenhe River Basin in different years was analyzed by weight analysis results and expert scoring method. The results show that the ecological environment evaluation indexes of Fenhe River Basin are : water loss, soil loss, water pollution and vegetation reduction; the influencing factors of the evaluation index are : rainfall factors, soil and water conservation measures, reservoir construction, industrial water use, coal mining, engineering construction, solid waste pollution, urban development, industrial structure change, population change; from 2000 to 2020, the ecological quality of the Fenhe River Basin continued to improve, indicating that the policies and measures adopted for ecological management were effective. The ecological deterioration near the main stream and tributaries of the middle and lower reaches of the Fenhe River is related to the pollution of mine environment and industrial sewage.

Research Advances in Removal Efficiency and Mechanism of Microplastics in Drinking Water Treatment Plants

Microplastics, as a novel type of environmental pollutant, have attracted notable attention in environmental research due to their widespread distribution and potential biological toxicity. Drinking water treatment plants play a crucial role in ensuring the safety of the water supply, with a particular focus on the removal efficiency of microplastics in drinking water treatment plants. Different treatment processes in water plants exhibit various removal efficiencies of microplastics and they operate through distinct removal mechanisms. To comprehensively analyze the removal efficiency and mechanism of microplastics in drinking water treatment plants, this study first examined the abundance and removal efficiency of microplastics of the influent and effluent of drinking water treatment plants. Subsequently, this study reviewed the removal efficiency and mechanism of four commonly used treatment processes： coagulation/flocculation/sedimentation, sand filtration, membrane filtration, and disinfection. The shortcomings and gaps in current studies were also pointed out. Finally, the assessment of microplastics abundance and human exposure in tap water was summarized and the future research direction was prospected from the perspectives of standardized sampling detection methods, nanoplastic detection, microplastics release in water supply systems, and risk assessment.

Copper Ion-Chelated and Polydopamine-Modified Hydroxypropyl Methylcellulose Nanoparticles with Multiple Responses for Intelligent Pesticide Release and Improved Foliar Deposition.

Intelligent controlled-release nanopesticides have been a crucial tactic in advanced precision agriculture during the past few years, which can improve pesticide utilization and reduce environmental pollution. Herein, a novel hydroxypropyl methylcellulose-based nanopesticide carrier (PCH) with pH-/enzyme-/near-infrared multiple responses was constructed by the initial cross-linking with dimethyl diallyl ammonium chloride and the subsequent copper ion chelation and polydopamine coating. Avermectin (Av) was further loaded to create the intelligent pesticide release system (APCH) by antisolvent precipitation. The release of APCH increases under near-infrared light (NIR) conditions, with an accumulative release that is 3.26 times higher than that without NIR. The contact angles of APCH on cabbage leaves are 33 and 29% lower than those of water and technical Av (Av-tech), respectively, verifying that APCH has a good wettability property. Simultaneously, APCH displays better insecticidal activity than Av formulations because of its outstanding ultraviolet (UV) light stability of Av. The degradation rate of Av in APCH is less than 2% in 50 h under UV light, which is considerably lower than that of Av-tech (∼60%). The biosafety assessments manifest that the PCH carrier has remarkable biological safety on the growth of nontarget organisms in a certain range. Overall, the APCH system is bio-friendly with multiple-response release behaviors, excellent UV light stability, and foliar deposition performance, which can offer a new strategy for sustainable agricultural development.

Heavy Metal Pollution Characteristics and Ecological Risk Assessment of Kafang Tin Tailings Pond

To study the pollution characteristics and ecological risks of heavy metals in tailings ponds is an important prerequisite for protecting the surrounding environment and human health. The total amount and morphology of five "toxic" heavy metals （As, Cr, Cd, Pb, and Hg） in Kafang tin tailings pond were determined. Based on the aforementioned, we analyzed the distribution characteristics of heavy metals. The potential ecological risks of heavy metals in tailings ponds were studied from the aspects of total amount and morphology. Sample data were analyzed using the geo-accumulation index method, potential ecological risk assessment method, and risk assessment criteria. The results showed that, from the perspective of the total amount of heavy metals, the spatial distribution of As was different, and the pollution was serious； the spatial distribution of Cd, Hg, Cr, and Pb was relatively uniform； the pollution of Cd and Hg was slight； and the pollution of Cr and Pb was controllable. From the perspective of the morphology of heavy metals, As, Cr, Pb, and Hg in tailings were mainly in the residual state and had low environmental pollution risk, whereas Cd in tailings was mainly in an oxidizable state and had high environmental pollution risks. Therefore, Kafang tin tailings pond should strengthen the control of As in tailings and pay attention to the potential pollution risks of Cd in tailings and the overall pollution risks of Hg, Pb, and Cr in the entire reservoir were controllable.

Evaluation of enzymatic and non-enzymatic biomarkers of sublethal cadmium toxicity in the freshwater mussel (Unio tigridis).

Mussels are filter-feeding animals with a sedentary lifestyle and thus, they were accepted as good bioindicator animals to investigate environmental pollution. In this study, freshwater mussels (Unio tigridis) were exposed to cadmium (0, 30, 90, 270 µg Cd/L) for up to 21 days. Then, the responses of several biomarkers belonging to the antioxidant, osmoregulation and nervous systems, as well as the energy reserves of mussels were investigated. The animals were fed on laboratory-cultured algae (Chlorella vulgaris) during the experiments. Data showed that the exposure conditions did not cause mussel mortality within 21 days, though the levels of all biomarkers altered significantly (p < 0.05) compared to controls. Cadmium exposures significantly altered the activities of antioxidant enzymes in the digestive glands. Similarly, malondialdehyde (MDA) levels in the digestive glands significantly increased after cadmium exposures. Likewise, acetylcholinesterase (AChE) activity and Ca-ATPase activity in the muscle significantly decreased. There were decreases in Na-ATPase and increases in Mg-ATPase activities in the gill. The total energy reserves of mussels significantly decreased, especially at the higher cadmium concentrations. This study showed that environmentally relevant cadmium concentrations could alter the levels of biomarkers belonging to different metabolic systems, emphasizing their possible usage in evaluating metal contamination.

Foreign Direct Investment, Institutional Quality, and Environmental Pollution in Selected African Countries

African countries increasingly attract foreign direct investment as they strive for economic growth and development. However, there have been concerns over the rising effects of FDI on pollution. These concerns are rooted in the potential for industrial activities associated with FDI to have adverse environmental impacts. Hence, the needs to tackle the problem of pollution cannot be overemphasized. One way to do this is by strengthening the quality of African institutions. This study was conducted to examine the effects of institutional quality and FDI on environmental pollution in selected African countries. Environmental pollution was measured using CO2 emission.The result of the PCSE estimator showed that institutional quality had negative effects on environmental pollution, but the effect of FDI was positive and insignificant. Also, the effect of moderating effect showed that institutional quality has the potential to reduce the positive effect of FDI on environmental pollution. It was recommended that African governments should strengthen the quality of their institutions by strengthening environmental governance frameworks.