Buildup Of Heavy Metals Research Articles

ROLE OF BIOTECHNOLOGY IN ABIOTIC STRESS TOLERANCE IN PLANTS

As population grows, abiotic stresses reduce plant growth and agricultural output, affecting global food security. Heat, cold, drought, salinity, and heavy metals affect crops. Heat stress from climate change disrupts cellular metabolism and lowers productivity. Tropical and subtropical crops suffer physiologically from cold stress. Climate variability affects drought, reducing crop output and germination. Salinity stunts growth and causes nutritional imbalances in big agricultural areas. Heavy metal buildup in soils threatens plant health. To overcome these problems, plants use osmotic adjustment, antioxidant defenses, and stress signaling pathways. CRISPR/Cas9 and other genetic engineering and molecular breeding methods may improve crop stress tolerance. Using omics technologies (genomics, transcriptomic, proteomics, and metabolomics) in breeding programs helps us understand stress tolerance processes and generate resilient crop types. This research is crucial for sustainable agriculture and global food security.

Influence of municipal waste treated sludge on the quality attributes of African marigold (Tagetes erecta)

Using treated sludge to amend soil in agriculture presents opportunities and challenges, particularly concerning the augmentation of heavy metals in cultivated plants. This research looks into how applying treated sludge affects the buildup of heavy metals in African marigold (Tagetes erecta), a popular ornamental plant that could potentially help with phytoremediation. Several treatment combinations were imposed, out of which treated sludge at 2.5 t/ha showed promising results. The effect of incorporating treated sludge was found to be better in terms of using conventional manures like Farm Yard Manure and Vermicompost in quantitative terms. The sludge processed at the treatment plant underwent strict treatment procedures, resulting in odourless material that can be used as an organic amendment with nutrients. Heavy metal concentrations in plant tissues were analyzed using Inductively Coupled Plasma Mass Spectrometry (ICPMS) to assess the uptake and accumulation of heavy metals by African marigolds. Results indicated that treated sludge application did not significantly influence the accumulation and bioavailability of heavy metals in African marigolds. The treated sludge helped plants grow better and absorb nutrients; it did not cause higher levels of harmful heavy metals like cadmium and lead in the plants. The levels of heavy metals found were lower than what is considered unsafe for plants. In addition, treated sludge can serve as a soil conditioner to enhance the physicochemical properties of the soil.

Impact of agricultural inputs on the abundance of heavy metals (Cu, Zn) in soil, water, and plants in the south of Algeria

he aim of our study is to assess the impact of agricultural inputs on the levels of heavy metals, specifically copper (Cu) and zinc (Zn), in soil, water, and plants in the oasis of El Ghrous, Branis, and Sidi Okba in Algeria. The existence of perilous substances in the surroundings is a significant ecological issue, endangering both human well-being and agricultural output. The overuse of fertilizers and pesticides may be causing heavy metals build-up. The aim will be to highlight a better understanding of the concentrations of copper (Cu) and zinc (Zn), considering as detrimental contaminants, after extensive utilization of agricultural inputs. In order to examine the levels of trace metals (TMs), we performed additional tests by comparing field samples using metal analysis techniques that involved ammonium acetate and EDTA, and detection by atomic absorption spectrophotometry. Our findings suggest that in soils affected by fertilizers and phytosanitary agents, the concentrations of Cu++ and Zn++ are below levels that would cause toxicity. Indeed, the levels of Cu++ are measured at 6.14 µg/g and the levels of Zn++ are measured at 4.97 µg/g. Nevertheless, the copper contents in irrigation waters from sites 01 and 02 beyond the levels that are considered dangerous. Similarly, copper levels in plants are categorized as hazardous. The findings emphasize the significance of implementing integrated pest management strategies in order to reduce the negative consequences of excessive use of agricultural inputs. Additionally, our study imposes the need to closely monitoring agricultural practices in order to mitigate environmental and public health hazards. Implementing sustainable farming practices and employing effective resource management strategies is crucial for safeguarding agricultural ecosystems and guaranteeing sustainable food production in the long run. Adopting an all-encompassing strategy is crucial for preserving the well-being of both the ecosystem and the populace.

Http://www.pjaec.pk/index.php/pjaec/article/view/1567

Humans' indiscriminate usage of heavy metals has a negative impact on the world's natural ecosystem. One of the main causes of contaminating the fresh and healthy atmosphere in rural Pakistan is the use of coal and soil in an improper manner by brick kilns. Different heavy metal concentrations and their impact on the surrounding areas of Pakistan's District Lakki Marwat were investigated in this study. Acid digestion methods were used to prepare samples, which were then examined using an Atomic Absorption Spectrophotometer. The concentrations of cadmium, iron, and lead in certain samples exceeded the WHO's permitted level, whereas nickel and zinc concentrations were within the limit. It was also discovered that the supply of raw materials is the key determinant in the buildup of heavy metals in the areas near brick not the age of the kiln.

Assessment of Heavy Metal Contamination in Irrigated Farmland and Associated Health Risks in Kano State, Nigeria: A Review

Study’s Excerpt/Novelty Soil pollution in Kano State is primarily caused by the use of contaminated irrigation water and household/industrial sludge as fertilizers, leading to heavy metal contamination in crops. The buildup of heavy metals in soil and crops poses significant health risks and potential food insecurity, necessitating multiple research projects to assess and address the situation. Implement regular monitoring of heavy metal levels in soils and crops, and establish guidelines for safe cultivation and consumption of vegetables grown on contaminated soils to mitigate health risks. Full Abstract The primary causes of soil pollution in Kano state, which leads to heavy metal contamination in crops grown from such soils, are using contaminated water for irrigation and household and industrial sludge as fertilizers. Along waterways where untreated wastewater flows, vegetables are planted. To determine the existing situation and potential preventative and remediation measures, it has become necessary to conduct multiple research projects on the levels of heavy metals in the soil and plants grown in Kano state, Nigeria. In light of this, this study has focused on the present and potential state of heavy metal buildup in soils and farmed crops and the potential health risks that may arise from this, including food insecurity. The main findings of the conducted research were that regular monitoring of the level of heavy metals in soils and crops should be established, and guidelines for the cultivation and consumption of leafy vegetables grown on contaminated soils should be set equally to avoid health risks.

R-Napropamide Potentially Regulates Cadmium Accumulation in Arabidopsis Shoots through Transport Channel Modulation.

Heavy metal contamination in soils poses a significant environmental threat to human health. This study examines the effects of the chiral herbicide napropamide (NAP) on Arabidopsis thaliana, focusing on growth metrics and cadmium (Cd) accumulation. R-NAP does not adversely affect plant growth compared to the control, whereas S-NAP significantly reduces root length and fresh weight. Notably, R-NAP markedly increases Cd accumulation in the shoots, exceeding levels observed in the control and S-NAP. This increase coincides with reduced photosynthetic efficiency. Noninvasive electrode techniques reveal a higher net Cd absorption flux in the root mature zone under R-NAP than S-NAP, although similar to the control. Transcriptomic analysis highlights significant stereoisomer differences in Cd transporters, predominantly under R-NAP treatment. SEM and molecular docking simulations support that R-NAP primarily upregulates transporters such as HMA4. The results suggest careful management of herbicides like R-NAP in contaminated fields to avoid excessive heavy metal buildup in crops.

Impact of brewery sludge application on heavy metal build-up, translocation, growth and yield of bread wheat (Triticum aestivum L.) crop in Northern Ethiopia

In a field study, the impact of different levels of brewery sludge (BS) enrichment on Triticum aestivum L. (wheat plants) was examined in terms of growth, yield, heavy metal absorption, and potential health risks linked to plant consumption. Using a randomized complete block design with seven treatments and three blocks, the study showed that applying up to 12 t ha−1 brewery sludge significantly improved all agronomic parameters (except harvest index) compared to control and mineral-fertilized soil. Heavy metal translocation was generally low, except for Cu and Pb. The sequence of heavy metal translocation was Cu > Pb > Cd > Ni > Zn > Mn > Cr from soil to spikes and Cu > Zn > Mn > Pb > Ni > Cd > Cr from soil to grain. Heavy metal loads were mostly higher in roots than in the above-ground crop parts. The target hazard quotient (THQ), hazard index (HI), and target cancer risk (TCR) within wheat grain remained within safe limits for all BS treatments. Consequently, consuming this wheat grain is considered safe regarding heavy metals. Thus, utilizing brewery sludge at 12 t ha−1 as a fertilizer for wheat production and as an alternative method for sludge disposal is plausible.

How plants respond to heavy metal contamination: a narrative review of proteomic studies and phytoremediation applications.

Heavy metal pollution caused by human activities is a serious threat to the environment and human health. Plants have evolved sophisticated defence systems to deal with heavy metal stress, with proteins and enzymes serving as critical intercepting agents for heavy metal toxicity reduction. Proteomics continues to be effective in identifying markers associated with stress response and metabolic processes. This review explores the complex interactions between heavy metal pollution and plant physiology, with an emphasis on proteomic and biotechnological perspectives. Over the last century, accelerated industrialization, agriculture activities, energy production, and urbanization have established a constant need for natural resources, resulting in environmental degradation. The widespread buildup of heavy metals in ecosystems as a result of human activity is especially concerning. Although some heavy metals are required by organisms in trace amounts, high concentrations pose serious risks to the ecosystem and human health. As immobile organisms, plants are directly exposed to heavy metal contamination, prompting the development of robust defence mechanisms. Proteomics has been used to understand how plants react to heavy metal stress. The development of proteomic techniques offers promising opportunities to improve plant tolerance to toxicity from heavy metals. Additionally, there is substantial scope for phytoremediation, a sustainable method that uses plants to extract, sequester, or eliminate contaminants in the context of changes in protein expression and total protein behaviour. Changes in proteins and enzymatic activities have been highlighted to illuminate the complex effects of heavy metal pollution on plant metabolism, and how proteomic research has revealed the plant's ability to mitigate heavy metal toxicity by intercepting vital nutrients, organic substances, and/or microorganisms.

Assessment of Heavy Metal Contamination and Health Risks in Road Deposited Sediments: A Study in Owerri, Nigeria

The study aims to conduct an ecological risk assessment and build a pollution model for assessing trace metal concentrations in road dust in Owerri, Nigeria. Key roadways in the urban area were chosen based on traffic volume, population density, and human activity. Data was collected at 500-meter intervals throughout each route, and silt samples were collected by systematic sweeping of a 1 square metre area covering road pavements and curbs. The examination found metallic pollutants such as chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), and lead (Pb) inside the RDS. Nickel (Ni), copper (Cu), cadmium (Cd), and lead (Pb) levels were substantially higher than their respective background values. Carbon monoxide levels along Port Harcourt Road, specifically 670 mg/l, are much higher than the background norm, indicating a considerable influence of human activity. Estimated enrichment values for the metallic elements ranged from insignificant (Mn) to extremely high (Co, Ni, Cu, Zn, Pb). Based on geoaccumulation index data, it can be concluded that the RDS has significant levels of contamination in terms of Ni and Pb, implying a considerable buildup of certain heavy metals, most likely due to anthropogenic acts. The study identified two major sources of heavy metal contamination: natural sources originating in the Earth's crust and transportation-related activities such as air deposition, corrosion, and vehicle degradation.

Sustainability Assessment after Twenty Years of Sewage Sludge Application on Calcareous Soil Following N or P Criterion

Sewage sludge is a valuable source of nutrients when applied to the soil. Research on its agricultural use has been focused on chemical parameters to prevent heavy metal buildup. However, soil quality includes a wider spectrum of indicators. Our aim was to evaluate the impacts of sludge application on the biological and physical soil properties of calcareous soil when sludge is applied in maize monoculture using fertilization dosage criteria determined by N input or soil P thresholds. A control based on mineral fertilization was also included. After 20 years, no differences were found in the biological indicators: earthworm and soil oribatid mite abundances. Five oribatid species were identified, but three predominated: Acrotritia ardua americana, Oribatula (Zygoribatula) excavata and Tectocepheus sarekensis. The latter two showed a maximum number of individuals five months after maize stalks were buried in soil, independent of fertilization treatment. Sludge significantly increased water-stable aggregates (up to 30%), but there was no difference in macroporosity (apparent pore diameter > 30 μm). Under irrigated calcareous soil, sewage sludge applied as fertilizer is a sustainable option, independent of the threshold criterion (N or P) used. Nevertheless, as the P threshold criterion allows for reduced P inputs, it is more sustainable over the long term.

Determination of Residual Presence of Toxic Heavy Metal in the Liver of LABEO BATA (HAMILTON, 1822) Using Rain Water Harvest System

Abstract: Fish are special among vertebrates because they may absorb metal from the water through their gills and from their food through their guts (direct and trophic absorption methods). Since the fish's gills are the primary organ targeted by metal toxicity, the direct uptake route is more significant. Most research on the toxicity and accumulation of metals in fish focuses on individual metals. But in the natural world, fish are exposed to mixes of many metals, whose toxicity levels typically differ from those of individual metals because of their additive, sometimes less than additive (antagonistic) effects, or higher than additive (synergistic) effects. This article discusses the build-up of heavy metals in fish organs and tissues, particularly in relation to the intake of water-borne metals via the trophic pathway. The trophic route is important because it is related with “Biological Magnification”. The fish we eat, usually comes from rivers or pond or bheri, in Kolkata. These are also contaminated with heavy metal toxicity. The rain water is contamination free from heavy metal. We collected live fish from market and kept them in “Rain Water Harvest System” for 24 hours. The accumulated heavy metal was expected to be eliminated from fish liver within 24 hours through the process of detoxification. We found that, even after 24 hours, fish liver contain certain heavy metal as residue. The model fish was Labeo bata (Hamilton,1822). Far more studies on metal interactions should be performed to reach the level of predictability

AMELIORATION OF CADMIUM STRESS ON TOMATO (LYCOPERSICON ESCULENTUM) BY TRIACONTANOL APPLICATION

Lead (Pb), copper (Cu), zinc (Zn), and cadmium (Cd) tend to build up in the roots of tomato plants and are then taken up by the leaves and fruits, resulting in significant removal from the soil. Plant growth and development are at risk due to the soil's buildup and toxicity of heavy metals (HMs). Cadmium, a hazardous element, inhibits the development and yield of tomatoes. Triacontanol (TRIA) enhances plant development when exposed to low concentrations of Cd, hence mitigating its harmful effects. This work used the exogenous triacontanol (TRIA) application to mitigate the adverse physiological impacts of cadmium (Cd) on tomato plants. The current study investigated tomatoes' physical characteristics, functions, and chemical composition to get a deeper understanding of how Triacontanol responds to stress caused by cadmium. Two experiments were laid out under a Completely Randomized Design (CRD), and three replications under a hydroponic system. In the first experiment, the effects of Cd on tomato were grown hydroponically and exposed to cadmium chloride at five concentration levels (control, 1.5, 03, 06 and 12µmol/L). While in the second experiment tomato grown hydroponically, and cadmium used in the form of CdCl2 at five concentration levels (control, 1.5, 03, 06 and 12µmol/L) with one level of TRIA 10µM/L was be applied to facilitate the Cadmium stress on plant. The Hoagland's solution was used to irrigate the plants after the initial 72 hours of pretreatment in both experiments at 35±1℃; 70-75%RH. Data for tomato plants' morphological, physiological, and biochemical characteristics was recorded. Results revealed that mitigation through triacontanol (TRIA) @ 10µmol/L best affects cadmium stress. It was noted that triacontanol (TRIA) @ 10µmol/L significantly affects tomato plants' morphological, enzymatic, and physiological characteristics at 1.5µmol/L of cadmium stress.

Nanoremediation approaches for the mitigation of heavy metal contamination in vegetables: An overview

Abstract Metals with high atomic weights and gravity are considered heavy metals (HMs). Rapid industrialization increases the content of harmful HMs in an ecosystem by affecting soil, water, and living organisms. One growing concern is a buildup of HMs in food crops including vegetables either by irrigation with wastewater containing HMs or from contaminated soil. Consumption of vegetables has potentially serious effects on living organisms. Various physical and chemical strategies are used but such methods have certain limitations. Nanoremediation, a combination of bioremediation and nanotechnology. represents an innovative way for sustainable removal of contaminants such as HMs. Nano-level understanding of cellular and molecular pathways is essential for treating HMs. Although the eco-toxicity of nanotechnology is a recent issue of concern, it is a promising strategy to deal with the pollution of the environment. These strategies can make the vegetables consumable with fewer HMs. Nanoparticles (NPs) are potentially adaptable for both in situ and ex situ HM treatment. This review provides a critical overview of recent nanoremediation technologies and the properties of NPs. Furthermore, considerable valuation of nanoremediation techniques was considered for dealing with contamination with special attention on health and the environment. The review further illustrates the ecological implementation of nanotechnology and provides a strong recommendation for the utilization of nanoremediation to improve the recent situation and justifiable future.

Impact assessment of heavy metals spiked wastewater irrigation on soil health in marigold (Tagetes patula L.)

A pot experiment was conducted to find out the impact assessment of heavymetals spiked wastewater irrigation on soil healthin marigold (Tagetes patula L., cv. Pusa Arpita) under irrigation with metals spiked wastewater at Water Technology Centre of ICAR-Indian Agricultural Research Institute, New Delhi during Rabi season of 2020-21. Sevan treatments were takenas T-1: Sole Groundwater Irrigation without spiking of heavy metal, T-2: Sole Wastewater Irrigation without spiking of heavy metal, T-3: Wastewater Irrigation spiked with Cd (0.005ppm), Cr (0.05ppm), Ni (0.1ppm) and Pb (2.5ppm), T-4:Wastewater Irrigation spiked with Cd (0.01ppm), Cr (0.1ppm), Ni (0.2ppm) and Pb (5.0ppm), T-5: Wastewater Irrigation spiked with Cd (0.1ppm), Cr (0.1ppm), Ni (2ppm) and Pb (10ppm) , T-6: Wastewater Irrigation spiked with Cd (0.25ppm), Cr (2.5ppm),Ni (5ppm) and Pb (30ppm), T-7: Wastewater Irrigation spiked with Cd (0.5ppm), Cr (5.0ppm), Ni (10ppm) and Pb (50ppm). Results indicated that soil health in-terms of pH, organic carbon, phosphorous, potassium and micronutrients (Cu, Fe, Mn, Zn) was significantly not changed where as significantly higher salinity (EC: 0.45 dS/m), nitrogen content (164.17 kg/ha) aswell as significantly higher concentration of Ni (0.76 mg/kg), Cr (1.66 mg/kg), Cd (0.18 mg/kg) and Pb (2.78 mg/kg) in irrigated soils were observed in the treatment T-7 where higher concentration of metals were spiked in wastewater. The present study may be concluded as the application of metals spiked wastewater irrigation may deteoriate the soil health by build-up of heavy metals under cultivation of marigold.

Human exposure to dust and heavy metals in industrial regions and its relationship with the prevalence of multiple sclerosis disease.

In recent decades, multiple sclerosis (MS) diseases have been significantly prevalent in some industrial areas of Iran, such as steel industrial areas in Isfahan province (central Iran). In this study, the environmental impacts of two steel mill factories in Isfahan province and their effects on the spread of MS in the region were investigated. To examine the extent of exposure, seasonal dust samples were collected from 15 sites around the two investigated factories. The annual dust deposition rate (DDR) was then determined and the concentrations of lead (Pb), cadmium (Cd), nickel (Ni), cobalt (Co), and manganese (Mn) in the dust samples were measured. Furthermore, the concentration of the mentioned elements was determined in the nail samples taken from 40 MS patients and 40 healthy people (control) living in the study region. The interpolated map extracted from the DDR values showed the highest dust deposition around the two studied steel factories, which decreases with increasing distance from them. The enrichment factor (EF) of heavy metals was the highest at the distance between the two steel factories, decreasing by moving away from them which indicate that these two steel factories are the source of investigated heavy metals in the region. The statistical analysis also revealed significant differences (P < 0.01) between the concentration of heavy metals measured in nail samples taken from MS patients and healthy people. The mean Pb concentration measured in the nail sample taken from MS patients was more than 18 times that of healthy people (93.45 and 5.02mg/kg, respectively). These results revealed a buildup of heavy metals in the body of MS patients much more than usual, originating from the activities of two investigated steel companies in the region.

Influence of Soil Organic Carbon, Water Holding Capacity, and Moisture Content on Heavy Metals in Rice Paddy Soils of Western Ghats of India

Analysis of soil samples collected from 16 rice paddy fields located in the Western Ghats region was performed to quantify the concentration of Cu, Zn, Mn, Fe, Ni, Cr, Cd, and Pb using atomic absorption spectroscopy. High concentrations of these heavy metals were found in rice paddy fields regularly cultivated using agrochemicals. We compared this concentration with soils of rice paddy field that was not under cultivation. Cu, Zn, Mn, Fe, Cr, Ni, Pb, and Cd showed increases of 1.2, 1.3, 2.3, 2.2, 1.8, 2.8, 1.8, and 8.5 times, respectively, in the rice paddy fields cultivated with synthetic fertilizers such as NPK, urea, potash, diammonium phosphate, etc., and several categories of pesticides belonging to the class organophosphates, carbamates, and acetanilide herbicide. In contaminated sites, the heavy metals exhibited maximum correlation with soil moisture content (SMC) (Zn, Fe, Cr, Ni, and Cd), soil organic content (SOC) (Fe, Cr, Ni, and Cd), and water holding capacity (WHC) (Cu, Pb, and Cd) than those observed for the reference site. The principal component analysis (PCA) revealed a total of 77.944% variance of heavy metals contributed from WHC (40.259%), SMC (20.854%), and SOC (16.832%). This indicates the build-up of heavy metals in rice paddy soils under the strong influence of moisture content, water holding capacity, and organic carbon content of the soil.

HEAVY METALS CONTENT IN CHEESE: A STUDY OF THEIR DIETARY INTAKE AND HEALTH RISK ASSESSMENT

Cheese represents an important source of essential amino acids, vitamins, and trace elements such as copper (Cu), and zinc (Zn). Cheese can be contaminated with toxic heavy metals due to the use of contaminated ingredients, or during the manufacture process, and distribution. This study was taken to estimate the residual contents of some toxic metals including lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg), and trace elements such as zinc (Zn) and copper (Cu) in five of the most consumed cheese types in Egypt including Domiati, Feta, Karish, Mish, and Rumi. Moreover, calculation of the dietary intakes, and health risk assessment among children and adults were conducted. The obtained results revealed that Mish cheese had the highest residual content of Pb, and As. Karish cheese had the highest content of Cd, and Zn. Mercury was not detected in Feta and Domiati cheese. Calculation of the estimated daily intakes, hazard ratio, and hazard index revealed that consumption of cheese among Egyptian adults and children would not pose health risks. However, such data should be handled carefully as consumption of cheese will provide considerable concentrations of the total buildup of heavy metals to the Egyptian consumers. In addition, consumption of cheese will provide part of the human needs of the essential trace elements including Zn, and Cu.

Heavy metals and micronutrients assessment in soil and groundwater using geospatial analyses under agricultural exploitation in dry areas

This study used a geospatial model to evaluate the regional distributions and buildup of various Heavy Metals (HM) and micronutrients as a result of groundwater irrigation used for lengthy periods in Egypt’s El-Kharga and El-Farafra oases, which were formed on western desert terrain, were the subject of the study. To fulfill this aim, field sampling of soil and groundwater was integrated with cartographic modeling. The evaluated HM concentrations in the water samples are below the permitted level for irrigation. The surface soil’s element concentrations were within acceptable limits. However, protracted mobility and a potency risk for soil smearing were not spotted. The apportionment of HM concentricity versus soil profundity showed that the assemblage was primarily in the topsoil. Future management plans should consider ongoing HM level monitoring. The lands are divided into three classes: II, III, and IV, according to their capabilities, while the soils are divided into three classes based on their suitability: moderately suitable class S2, marginally acceptable class S3, and permanently unsuitable class N2. Additionally, soil fertility and quality were categorized into low and moderate categories. Land evaluations indicate that they are promising areas for agricultural investment under the conditions of using modern agricultural techniques. The most important results of the study are that the non-technical use of irrigation water in some areas has exacerbated the problems of salinity, especially in those where the drainage characteristics are poor. Concentrations of HM were found only in agricultural areas adjacent to urban areas and poor drainage, especially in agricultural areas reclaimed for more than 50 years. High concentrations of HM were also found in shallow wells close to the same places, and there were no significant concentrations in blind wells. The main recommendation of the study is the necessity of using modern agricultural and irrigation systems in those places.

The seasonal assessment of heavy metals pollution in water, sediments, and fish of grey mullet, red seabream, and sardine from the Mediterranean coast, Damietta, North Egypt

The current study investigated the deposit of heavy metals, including copper (Cu), zinc (Zn), cadmium (Cd), manganese (Mn), lead (Pb), chromium (Cr), and iron (Fe) in grey mullet (Mugil cephalus), red seabream (Pagrus pagrus), and sardine (Sardinella aruita) over winter and spring seasons 2022 at the Damietta port, a marine port constructed in 1982 on the north coast of Egypt, and the surrounding region. Water, sediment, and fish samples were collected from four sites near Damietta port throughout the spring and winter of 2022 to evaluate the amount of heavy metal in water, sediment, muscles, and fish liver. Heavy metal concentrations significantly differed across organs; however, their levels in liver tissues exceeded those in muscle tissues. It was noted that M. cephalus had the highest concentrations of heavy metals compared with other fish species. Heavy metals accumulation in fish organs was in the following order: Fe > Zn > Mn > Pb >Cu > Ni > Cd > Cr. During winter season, metals levels in water samples were in the following sequence: Fe > Ni > Zn > Cd > Cr > Pb > Cu > Mn, meanwhile in spring season, the order was as follows: Ni > Pb > Fe > Cr > Zn > Cd > Cu > Mn. During the winter time, the order of metals levels in sediment samples was Zn > Fe > Mn > Cu > Pb > Ni > Cd > Cr, but in the springtime, it was Zn > Fe > Mn > Cu > Ni > Pb > Cd > Cr. Finally, the human risk assessment concluded that grey mullet, red seabream, and sardine in Damietta port and neighboring regions are safe for human feeding and that various wastes may be disposed of securely, avoiding the buildup of heavy metals.

Molecular cloning, characterization, and tissue distribution of c-Myc from blood clam Tegillarca granosa and its role in cadmium-induced stress response

Cadmium (Cd) pollution threatens the cultivation of the blood clam Tegillarca granosa (T. granosa) in coastal regions of the East China Sea. The molecular mechanisms regulating Cd stress response and detoxification in blood clams are largely unclear. In the present study, the full-length T. granosa c-Myc (Tgc-Myc) cDNA was cloned for the first time. The 3063-bp cDNA consisted of a 129-bp 5′ untranslated region (UTR), a 1746-bp 3′ UTR, and a 1188-bp open reading frame encoding a predicted protein of 395 amino acid residues. The predicted protein had a calculated molecular weight of 44.9 kDa and an estimated isoelectric point of 6.82. The predicted protein contained an N-terminal transactivation domain and a C-terminal basic helix-loop-helix leucine zipper domain, which are conserved functional domains of c-Myc proteins. Tgc-Myc showed broad tissue distribution in blood clams, with the highest expression detected in the gill and hepatopancreas. Exposure to Cd, a major heavy metal pollutant in coastal regions of the East China Sea, induced Tgc-Myc expression in gill tissues. Tgc-Myc knockdown led to reduced expression of a variety of stress response/detoxification genes in blood clams cultivated in Cd-contaminated seawater. Tgc-Myc knockdown also led to decreased expression of IGF1R, a proto-oncogene that promotes cell proliferation. These findings indicated that Tgc-Myc regulates Cd-induced stress response and detoxification in blood clams. The upregulation of Tgc-Myc may serve as an approach to generate strains with an enhanced detoxification response and consequently a low heavy metal buildup.