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Research on heavy metal pollution in horticultural farms located around lakes in the Central Ethiopian Rift Valley Region has focused on measuring the levels of heavy metals and their health implications. However, the ecological risks of horticultural farms contaminated with heavy metals in this region have not been studied. The current study addresses this gap by providing information on the degree of heavy metal contamination and the ecological risk associated with horticultural farms around Lake Ziway, using various pollution indices. An inductively coupled plasma optical emission spectrometer (ICP‐OES) was used to measure the concentrations of nine heavy metals (As, Cd, Co, Cu, Cr, Ni, Pb, Hg, and Zn) in a total of 30 composite soil and irrigation water samples, each consisting of a mix of six subsamples. The results indicated that the mean concentrations of Hg, Cd, Pb, and Zn in soils collected from all the sampling sites exceeded the FAO/WHO maximum permissible limit (MPL). The values of both the contamination factor (CF) and contamination degree (Cd) of the heavy metals ranged from 0.04 to 2.66 and 2.81 to 6.14, respectively, indicating a low to medium level of contamination for both indices. The pollution load index (PLI) values of 0.451, 0.449, and 0.157 for sites 2, 1, and 3, respectively, indicate "unpolluted" to "moderately polluted" levels of heavy metal pollution. However, the ecological risk indices (ERIs) at sites 2 and 1 (158.92 and 141, respectively) showed a potentially high ecological risk due to soil pollution. Therefore, close monitoring and early intervention mechanisms must be in place to control pollution in the study area. [ABSTRACT FROM AUTHOR]

Health implications for the population due to consuming contaminated crops have been a great concern worldwide. This study aimed to measure the levels of potential toxic elements in lentils and their growing soil in Dawunt Woreda, Ethiopia. Accordingly, 15 soil samples along with the lentil samples were collected to measure the level of potential toxic elements, including chromium (Cr), manganese (Mn), iron (Fe), lead (Pb), cadmium (Cd), copper (Cu), and cobalt (Co), by using an inductively coupled plasma optical emission spectrometer and for assessing the potential ecological and human health risk. The wet digestion method using aqua regia (HCl/HNO3 3 : 1) was employed for soil and lentil sample preparation. The mean concentrations of Fe, Mn, Co, Cu, Cd, Pb, and Cr in the lentil sample were 60.4, 9.68, 0.75, 5.7, 0.25, 0.9, and 1.15 mg/kg, respectively. In soil, the mean concentrations of Fe, Mn, Co, Cu, Cd, Pb, and Cr were 649, 19.9, 3.32, 40.0, 15.2, 1.83, and 69.1 mg/kg, respectively. All of the potential toxic metals in agricultural soil and lentil samples were found to be below the reference level set by the World Health Organization, except Cd, in the soil samples. Five single metal and three cumulative pollution index parameters were employed for the data and results showed that Fe, Cu, and Cr moderately pollute the soil and are highly contaminated by Cd. The cumulative pollution indices also confirmed that the extent of soil pollution varied from highly contaminated to moderate contamination. The possible health risks at various exposure routes have also been estimated. The single-metal and cumulative-metals health risks (cancer and noncancer) of adults and children due to chronic exposure to soil and consumption of lentils were estimated using the health quotient and health index values as per the United States Environmental Protection Agency guidelines. Thus, the results revealed no significant adverse health risks (cancer and noncancer) for adults and children. Therefore, the inhabitants in the study area have no significant health impacts due to either the consumption of lentil crops or exposure to agricultural soil particles. [ABSTRACT FROM AUTHOR]

The contamination of aquatic environments by heavy metals can have detrimental effects on fish, impacting their growth and overall health, including the regulation of antioxidant genes. An investigation was carried out to assess the distribution and habitat of Gymnocypris eckloni in the Yellow River basin. Simultaneously, heavy metal concentrations in its habitat and in selected locations within the upper Yellow River were measured. In an effort to explore the potential roles of specific genes in antioxidant responses, G. eckloni was exposed to low concentrations of copper (Cu2+) and lead (Pb2+) for varying durations (12, 24, and 48 hours). The mRNA levels of GeCu/Zn-SOD, GeMn-SOD, GeHsp90, and GeMT were quantified in the gills, kidneys, and liver through qRT-PCR. The findings suggest that the habitat of G. eckloni is generally safe; however, occasional exceedances of safety standards could pose a potential threat to its growth. Importantly, the expression of GeCu/Zn-SOD, GeMn-SOD, GeHsp90, and GeMT exhibited responses to the low concentrations of copper-induced and lead-induced stress. Notably, GeCu/Zn-SOD, GeMn-SOD, and GeMT demonstrated heightened sensitivity to lead compared to copper. Furthermore, the expression of these genes displayed tissue-specific responses under identical metal stress conditions. These results indicate that GeCu/Zn-SOD, GeMn-SOD, GeHsp90, and GeMT genes have the potential to serve as early, sensitive biomarkers for the detection of metal toxicity induced by Cu2+ and Pb2+. This study also provides valuable insights into the functioning of antioxidant genes under oxidative stress in fish. [ABSTRACT FROM AUTHOR]

In this study, for the first time, the levels of thirteen micro- and macromineral nutrients in the leaves, seeds, and supportive soil of Moringa stenopetala (M. stenopetala) were simultaneously determined using microwave plasma atomic emission spectroscopy (MP-AES). The samples were collected during the arid season, in 2019 from the three main M. stenopetala growing areas in southern Ethiopia (Chano Mile Kebele, Nechisar Kebele, and Konso Special Woreda). A novel digestion method for leaf and seed samples was developed using an optimized acid mixture (2.5 : 0.75 : 0.5 of HNO3, HClO4, and H2O2) at 240°C for 2 hrs and 30 min, resulting in clear and colorless solutions. The method makes the digestion process more efficient by minimizing the reagent volume, reducing digestion temperature and time, and simplifying the overall procedure. The efficiency of the optimized procedure was validated by spiking experiments, and the percentage recovery ranged between 94 and 110%. Under optimized experimental conditions, higher concentrations of essential minerals (K, Na, Ca, and Mg) were observed in the plant leaf and seed samples from the three areas. In addition, significant amounts of trace elements (Fe, Mn, Zn, and Cu) were also found. Importantly, no traces of the toxic elements (Cd and Pb) were detected in any of the analyzed samples, suggesting that the leaves and seeds of M. stenopetala are valuable sources of both micro- and macromineral nutrients and are safe from toxic metals. From a dietary perspective, the seed contains almost comparable concentrations of minerals as the leaves. As a result, the seeds of M. stenopetala can serve as an alternative source of minerals and play a role in overcoming the current global food crisis, particularly in the dry season. Analysis of variance at a 95% confidence level revealed significant differences in the levels of all mineral nutrients between the three sample means except K, Ca, Co, and Cu. Generally, the developed method includes an innovative digestion procedure that minimizes reagent consumption, operates at lower temperatures, and requires shorter digestion times, thereby optimizing resource utilization and maintaining analytical accuracy. Notably, the absence of toxic elements in the MP-AES procedure highlights the safety and reliability of M. stenopetala leaves and seeds as valuable, contamination-free sources of essential nutrients. [ABSTRACT FROM AUTHOR]

Longyan City in Fujian Province is one of China's top-quality tobacco-producing areas and plays an essential role in local economic development. To determine the correlation between heavy metal content in tobacco leaves and soil factors, soil physical and chemical properties and heavy metal contents of lead, cadmium, and copper in tobacco leaves were measured and analyzed by the correlation regression method. The content of lead, cadmium, and copper in soil was determined using hydrochloric acid extraction-AAS and graphite furnace atomic absorption spectrometry. Inductively coupled plasma-mass spectrometry was used to determine heavy metal in tobacco leaf. The findings revealed that the average concentrations of lead, cadmium, and copper in the soil were 12.1, 0.092, and 3.88 mg/kg, respectively. In contrast, the average levels of lead, cadmium, and copper in tobacco leaves were 2.33, 4.89, and 4.35 mg/kg, respectively. The cadmium enrichment coefficient of 54.3 was higher than lead and copper, indicating a greater health risk. Soil pH value was negatively correlated with lead content in tobacco leaf, while potassium and phosphorus nutrient levels were negatively correlated with copper content. In contrast, a positive correlation was established between the presence of organic matter with cadmium content in tobacco leaves. The prediction models of lead, cadmium, and copper in tobacco leaves can be expressed by the regression equation corresponding to each heavy metal as follows: Y Pb = 2.33 − 0.005 ∗ X K + 0.007 ∗ X N − 0.271 ∗ X pH + 0.065 ∗ X Pb ( R 2 = 0.787), Y Cd = 1.55 + 0.012 ∗ X OM − 0.014 ∗ X Cu + 34.6 ∗ X Cd ( R 2 = 0.891), and Y Cu = 4.64 − 0.029 ∗ X P − 0.007 ∗ X K + 0.245 ∗ X Cu ( R 2 = 0.724), respectively. The prediction models above provide an effective predictive tool for assessing heavy metal risk in tobacco leaves using soil properties in the study area. [ABSTRACT FROM AUTHOR]

Contamination of the environmental receptors with heavy metals due to mining is a major topical environmental issue in Ghana. This research investigates the possible ecological and human health risks of heavy metal impacts due to mining in the Amansie West District in Ghana. A total of 18 soil samples were taken from the Bontesso illegal mining site in the district and analyzed for the levels of arsenic (As), cadmium (Cd), copper (Cu), nickel (Ni), and lead (Pb) using atomic absorption spectrometry (AAS). From principal component analysis, cluster analysis, and correlation coefficient analysis, the metals are derived from multiple sources, with substantial levels of correlations. Using geo-accumulation index (Igeo), contamination factor (CF), degree of contamination (Cd), pollution load index (PLI), ecological risk index (Er), and noncarcinogenic and carcinogenic risks, respectively, the impacts of As (12.2 mg/kg) and Cd (1.3 mg/kg) are above the WHO stipulated limit. Findings for pollution indices indicate moderate contamination, while HQ < 1 for inhalation and dermal exposure route, except for ingestion which is HQ > 1. Based on the USEPA standard, the carcinogenic risk of the pollutants for humans is higher than the range of 1 × 10−6 to 1 × 10−4. Furthermore, the ingestion route represents the highest contributor to cancer risk with arsenic posing the greatest risk. The results so far suggest that chemical components gradually accumulate and thus emphasize the importance of implementing the necessary mitigation methods to minimize the impacts of illegal mining activities in the study area. [ABSTRACT FROM AUTHOR]

Hazardous heavy metal ions such as copper, zinc, nickel, chromium, cadmium, and lead engender a potential risk to human health. Among the processes involved in the retention of these contaminants, adsorption is advantageous for removing toxic metals because of its environmentally friendly aspect, efficiency, and low-cost operation. Information on the adsorption of heavy metals in soils from the semiarid region of northeastern Brazil is still scarce. In this study, the adsorption of heavy metals (Cd, Cu, Zn, Ni, and Pb) by a semiarid Brazilian bentonitic soil is investigated. This soil has been used as a bottom liner in an experimental municipal solid waste (MSW) cell located in Campina Grande, State of Paraíba, Brazil. The experimental cell consists of a landfill unit on an experimental scale, with the same constructive elements of a sanitary landfill. Disturbed and undisturbed samples of the investigated soil were collected at a quarry in the rural zone of Boa Vista (state of Paraiba, Northeast Brazil). Sorption attributes were determined via batch tests with a soil-solution ratio of 1 : 12.5 (4 g of dry soil to 50 mL of solution). Linear, Freundlich, and Langmuir isotherms were fitted to the experimental data, using as fitting parameters Pearson correlation coefficient ( R 2 ) and p value with a significance level α = 5 %. The ascending order of maximum adsorption capacity for heavy metals followed the series Ni < Cr < Zn < Cd < Cu < Pb. The maximum adsorbent capacities obtained were similar to those of other Brazilian soils and other adsorbents. Therefore, the studied soil has a high potential to be used in the retention of heavy metals. [ABSTRACT FROM AUTHOR]

Drinking water quality is fundamental to human physiology and health. The aim of this study was to assess the quality of drinking water in Gazer Town and selected kebele, in south Ari district, South Omo zone, Southern Ethiopia. A total of four drinking water samples were collected from densely populated urban areas of the Gazer Town and one rural Kebele. All the collected samples were analyzed for eight heavy metals, (Cd, Co, Cu, Cr, Fe, Mn, Pb, and Zn) using standard procedures. The results were compared with other national and international standards. Among the analyzed samples, drinking water samples collected from selected kebele (Aynalem kebele), show mean concentrations heavy metals in (μg/L), (Mn (973 ± 10), Cu (1068 ± 1.5), Cr (2785 ± 25), Fe (4302 ± 15), Cd (1218 ± 18), Pb (720 ± 12), Co (1478 ± 3), and Zn (1790 ± 5)), and the results revel except, Co and Zn metals, all show concentrations higher than the national and international standards (such as USEPA (2008), WHO (2011), and New Zealand) recommended values. Among the eight heavy metals analyzed from drinking waters in Gazer Town, Cd and Cr were below the method detection than that of all sampling area. However, the concentration of Mn, Pb, Co, Cu, Fe, and Zn were ranged from mean values of 9 μg/L, 17.6 μg/L, 7.6 μg/L, 12 μg/L, 765 μg/L, and 494 μg/L, respectively. Except Pb metals, the analyzed metals in waters were below the currently recommended guidelines for drinking. Therefore, the government should adopt some treatment technologies such as sedimentation and aeration to minimize the concentration of zinc for safe drinking the water to the community of Gazer Town. [ABSTRACT FROM AUTHOR]

Concentrations of heavy metals, namely, chromium, lead, cadmium, and copper, were evaluated in the water samples and selected fish organs (Labeobarbus intermedius) from the Borkena River, Ethiopia. The concentrations of these metals were determined using ELICO's SL-176 double-beam atomic absorption spectrophotometer (AAS). The distribution of heavy metals in water samples analyzed was in the order of magnitude of Cu > Cr > Cd > Pb. The average heavy metal concentrations recorded in the water samples were below the maximum permissible limit established by international and national organizations (WHO, EPA, and USEPA), except for cadmium. Organ specificity was observed for accumulating the selected heavy metals in the order of liver > kidney > muscles. Pearson's correlation results revealed that Cr and Cd originated from similar sources. Hazard quotient (HQ) and total hazard index (THI) results showed that Cu, Cr, Cd, and Pb contents were safe and might not have adverse public health effects. From the point of carcinogenic risk, this study suggests that the observed Cr and Cd concentrations possibly pose a risk of developing cancer in the future. Controlling waste at the source and implementing remediation strategies should be done to reduce heavy metal pollution in the river. [ABSTRACT FROM AUTHOR]

Introduction. Fresh vegetables are of a great value and the most common foods in the human diet around the world. They contain minerals, vitamins, antioxidants, antimetabolites, protein, carbohydrates, and water. However, they are a major source of heavy metals, which contain both essential and toxic heavy metals over a wide range of concentrations. The study sites serve as a regional commercial center, where vegetables such as cabbages, onions, carrots, potatoes, beetroots, lettuce, and tomatoes were irrigated year round and sold to consumers. The aim of the study was to determine the level of cadmium, chromium, copper, and lead and to estimate the health risks associated with their daily intake of vegetables marketed in Bahir Dar town, Northwest Ethiopia. Methods. The concentrations of copper (Cu), chromium (Cr), cadmium (Cd), and lead (Pb) were determined, and their health risks were estimated using estimated daily intake (EDI), target hazard quotient (THQ), hazard index (HI), and target cancer risk (TCR) for selected heavy metals by using flame atomic absorption spectrometry. A total of 5 kg composite samples for each type of vegetable were collected by simple random sampling from an open market in Bahir Dar town, Northwest Ethiopia, and subsamples (1.25 kg) were digested via the wet digestion method. Results. The average concentrations of Cr and Cu in all selected vegetables were lower than the maximum limit of expected values. However, the concentration (mg.kg−1) of Pb in carrots, potatoes, and beetroots exceeded the safe limit of 0.3 mg·kg−1 set by the FAO/WHO and the concentration of Cd (mg·kg−1) in carrots, which is higher than the FAO/WHO limit, 0.2 mg·kg−1, in dry weight. The health index (HI) values (mg·kg−1 day−1) of all vegetables except carrots were lower than one. The TCR values for Pb, Cd, and Cr in all vegetables exceeded the US-EPA recommended threshold risk limit, but the TCR value of carrot was above the moderate risk limit (>1 × 10−3) set by the US-EPA. Conclusion. This study indicated that the concentration level of lead and cadmium in potatoes, onions, carrots, and beetroots marketed in Bahir Dar town is not safe for use by the local community. The consumption of carrots in the study area may cause both noncancerous and cancerous health risks. Therefore, regular monitoring of these toxic metals in vegetables should be carried out to prevent heavy metal toxicity associated with the consumption of those vegetables marketed in Bahir Dar town, Ethiopia. [ABSTRACT FROM AUTHOR]

This study's goal was to learn more about how agrowaste plants tolerate, absorb, and accumulate a number of metals that are of relevance to the environment. Adsorption of lead (Pb), chromium (Cr), selenium (Se), copper (Cu), and zinc (Zn) ions from synthetic aqueous solutions and wastewater using natural waste residues (NWRs) such as moringa, Lupinus, sugarcane straw, and tea residue was evaluated. The adsorbents used for this study were prepared by washing, drying, and grinding. Fourier-transform infrared (FT-IR) spectroscopy and scanning electron microscope (SEM) analysis were used to characterize the adsorbents' waste residues. The effect of different parameters such as pH, dose of adsorbents, and the initial concentration of heavy metals, as well as the adsorption isotherm parameters were studied. Moringa, Lupinus, sugarcane straw, or tea residue results were found to fit the Langmuir and Freundlich adsorption isotherms. The adsorption capacity reached 14.59, 16.10, 12.73, and 15.01 mg/g, respectively. The adsorption study's overall results indicated the removal efficiency pattern as moringa > tea > Lupinus > sugarcane straw. At a dose of 0.5 g/L, the maximum removal percentages for lead, chromium, selenium, copper, and zinc ions were 90.2, 76.55, 70.55, 76.6, and 78.9, respectively. The materials might be regarded as efficient adsorbents for extracting the ions Pb, Cr, Se, Cu, and Zn from wastewater, according to the research. [ABSTRACT FROM AUTHOR]

The presence of heavy metals in wastewater, such as Ni, Pb, Cd, V, Cr, and Cu, is a serious environmental problem. This kind of inorganic pollutant is not biodegradable for several years, and its harmful effect is cumulative. Recently, semiconductor nanomaterials based on metal oxides have gained interest due to their efficiency in the removal of heavy metals from contaminated water, by inducing photocatalytic ion reduction when they absorb light of the appropriate wavelength. The most commonly applied semiconductor oxides for these purposes are titanium oxide (TiO2), zinc oxide (ZnO), and binary nanomaterials composed of both types of oxides. The main purpose of this work is to critically analyse the existent literature concerning this topic focusing specially in the most important factors affecting the adsorption or photocatalytic capacities of this type of nanomaterials. In particular, photocatalytic activity is altered by various factors, such as proportion of polymorphs, synthesis method, surface area, concentration of defects and particle size, among others. After a survey of the actual literature, it was found that, although these metal oxides have low absorption capacity for visible light, it is possible to obtain an acceptable heavy metal reduction performance by sensitization with dyes, doping with metallic or nonmetallic atoms, introduction of defects, or the coupling of two or more semiconductors. [ABSTRACT FROM AUTHOR]

Most galvanic process industries treat their effluents by chemical precipitation methods. Such a method produces an amount of galvanic sludge that is often disposed of inappropriately to the environment, causing major environmental damage. These rejects present high concentrations of toxic metallic ions, such as copper (Cu(II)), lead (Pb(II)), nickel (Ni(II)), and cadmium (Cd(II)). Several alternatives have been proposed to contribute in a cheaper and efficient way to treat these effluents. This study aimed to describe the results obtained in the removal of the concentrations of Cu(II), Ni(II), Cd(II), and Pb(II) ions, present in an aqueous solution, by the use of a hybrid system combining the adsorption and electroflotation processes simultaneously. The adsorbent materials used were two Brazilian soil clays classified as sodium clay (SC) and ferric clay (FC). For the electroflotation process, aluminum, iron, and stainless-steel electrodes were used. The obtained data showed good efficiency in the removal of the four metallic ion concentrations. The best results presented a reduction in the concentration of Cu(II), Ni(II), Cd(II), and Pb(II) ions of 50.11%, 36.71%, 21.59%, and 23.43%, respectively, when it was used the hybrid system formed by the ferrous clay as adsorbent and the aluminum electrode for the electroflotation process. [ABSTRACT FROM AUTHOR]

Background. Heavy metals in excessive levels are hazardous to ecosystems as they can bioaccumulate in organisms, have toxic effects on biota, and even cause mortality in most life forms. Methodology. The present study consists of two studies; initially, different concentrations of copper were biosorbed by using 1 gm powder of various biosorbents such as orange peels (OP), pomegranate peels (POP), and peanut peels (PP). Furthermore, the biosorbed water was used to irrigate soil when the mung beans were cultivated. The growth parameters of plants growing under induced copper stress and treated with different bioabsorbed waters were also evaluated. Results. The results revealed that, among all biosorbents, the copper biosorption capacity of orange peels was maximum (90%), followed by pomegranate peel. The results of the second experiment exhibited that the plants irrigated with biosorbed water did not show metal toxicity. A remarkable increase in shoot length, shoot fresh weight, and shoot dry weight was observed (29.8 cm, 15.4 g, and 14 g, respectively) when exposed to biosorbent water with peanut peels + 200 mg kg−1 (Cu2+). Similarly, pomegranate peel biosorbed water turned out to be an effective treatment to enhance root length, root fresh weight, and root dry weight (6.81 cm, 4.07 g, and 2.66 g, respectively) and resist against induced heavy metal stress conditions at higher concentration (200 mg kg−1). Furthermore, orange peel biosorbed water elevated the total chlorophyll content and soluble sugar content in mung bean (1.56 mg/g and 1.89 mg/g). The highest tolerance index of mung bean plant grown under the stress of Cu2+ metal was induced by orange peel biosorbed water. Conclusion. Biosorption is an environmentally friendly approach to mitigate heavy metals from the water. The studies showed that agricultural wastes have enough bioabsorption potential and should be used to absorb the heavy metal present in water. [ABSTRACT FROM AUTHOR]

This study focused on determining selected proximate compositions, such as moisture content, ash content, crude fibre content, and crude fat content, of kocho and bulla enset products collected from Bechi, Fide, Yeki, Zinki, Addis Alem, and Korcha kebeles of Yeki woreda. Besides, heavy metals such as iron, copper, manganese, zinc, and lead have been analyzed. The result showed that all proximate compositions analyzed agree with other conducted researches, except moisture content because of heavy rainfall in Yeki woreda. On the other hand, the results obtained for iron and zinc were higher than the permissible limit set by international standards, while that of manganese was slightly higher than the standard limit. On the other hand, the results obtained for copper were below the permissible limit set, while lead was not detected in all samples. Therefore, the investigated kocho and bulla products can provide an appreciable amount of analyzed minerals. [ABSTRACT FROM AUTHOR]

Among the water-polluting substances, heavy metals stand out due to their carcinogenic and toxic effects on the creatures and environment. This study aimed to scrutinize the effectiveness of sewage sludge-based activated carbon in the removal of copper and cadmium from aqueous solutions in column study. Detection of breakthrough curves and related parameters was conducted by varying bed depths (3, 6, and 9 cm). The solution with an initial metal concentration (IMC) of 100 ppm was pumped to the column at a flow rate of 2 mL/min. In the process of copper removal, the breakthrough points for depths 3 cm, 6 cm, and 9 cm were achieved at 10 min, 15 min, and 60 min, respectively, whereas breakthrough points of similar depths in cadmium removal process were achieved at 5 min, 10 min, and 30 min, respectively. Adsorption kinetics were analyzed using the Adams–Bohart, Yoon–Nelson, and Thomas kinetics models. The Adams–Bohart model described only the initial part of breakthrough curves. The Thomas model represented the adsorption process with coefficients of determination (R2) ranging between 0.90–0.95 for cadmium removal and 0.89–0.96 for copper removal, while the coefficients of determination of Yoon–Nelson ranged between 0.89–0.94 for cadmium and 0.95–0.97 for copper. Yoon–Nelson was fitted well with copper removal data, while removal of cadmium data was best described by the Thomas model. This study demonstrated that using sewage sludge-based activated carbon to remove heavy metals is an alternative, more cost-effective option to reach the objectives of sustainable development. [ABSTRACT FROM AUTHOR]