Increase In Concentration Of Heavy Metals Research Articles

Evaluation of physicochemical parameters and heavy metal concentrations in shrimp (<i>Penaeus monodon</i>), sediment and surrounding water of the Mangrove Swamps, Rivers State, Nigeria

The study focused on the evaluation of the physiochemical and heavy metal concentration in shrimp (P. monodon), sediments and surface water of Ikpukulu, Kalio, and Ogoloma swamps in Okrika Local Government Area, Rivers State, Nigeria. The following parameters were examined: temperature, potential hydrogen, electrical conductivity, salinity, dissolved oxygen, biochemical oxygen demand, total dissolved oxygen, temperature, and the content of heavy metals (Cd, Cu, and Cr) in surface water, sediments, and shrimp. The pH values (p > 0.05) did not significantly differ amongst the stations. The three sampling station readings of pH were below WHO and FEPA (standards). The temperature data from the three stations did not show any significant differences (p > 0.05), but when compared to the standards, all of the readings were much lower. Result from Ogoloma showed that it had lowest electrical conductivity ratings of the three stations, although overall, the values were higher than the norms. At Kalio, the highest Total Dissolved Solids value (9348.6 ± 67 mg/L) was recorded. When compared to the standards, the salinity values of the three stations were noticeably higher. For Biological oxygen demand, there was no significant (p>0.05) difference between the three stations, but comparing the values to the standards they were all significantly (p>0.05) lower. Heavy metal analysis showed that in the sediment, Copper concentration at Ogoloma was significantly (p>0.05) higher among the three metals in the three stations. Copper and chromium concentrations in the three stations were much higher than the standard. Among the three metals found in the water at the three stations, copper had the highest quantities; the content of copper in Ogoloma was noticeably greater than the standard. Of the threelocations, Ogoloma exhibited a noticeably greater concentration of copper for Shrimp. Thefindings highlight the necessity for preventative action by pointing to an increase in heavy metalconcentrations in the Mangrove swamp area.

A research on the effect of plasma spectrum collection device on LIBS spectral intensity

Only a small amount of spectral information is collected because the collection solid angle of the optical fiber probe and lens is very limited when collecting spectral information. To overcome this limitation, this study presents a novel method for acquiring plasma spectral information from various spatial directions. A parabolic-shaped plasma spectral collection device (PSCD) is employed to effectively collect more spectral information into the spectrometer, thereby enhancing the overall spectral intensity. The research objects in this study were soil samples containing different concentrations of heavy metals Pb, Cr, and Cd. The results indicate that the PSCD significantly enhances the spectral signal, with an enhancement rate of up to 45%. Moreover, the signal-to-noise ratio also increases by as much as 36%. Simultaneously, when compared to the absence of a device, it is found that there is no significant variation in plasma temperature when the PSCD is utilized. This observation eliminates the impact of the spatial effect caused by the PSCD on the spectral intensity. Consequently, a concentration-spectral intensity relationship curve is established under the PSCD. The results revealed that the linear fitting R 2 for Pb, Cr, and Cd increased by 0.011, 0.001, and 0.054, respectively. Additionally, the limit of detection (LOD) decreased by 0.361 ppm, 0.901 ppm, and 0.602 ppm, respectively. These findings indicate that the spectral enhancement rate elevates with the increase in heavy metal concentration. Hence, the PSCD can effectively enhance the spectral intensity and reduce the detection limit of heavy metals in soil.

Water Quality Assessment and Heavy Metal Levels in Mudskipper (Periophthalmus Papilio), Sediments and Water of Mangrove Swamps, Rivers State, Nigeria

A study was conducted to determine the physicochemical parameters of surface water and heavy metal concentrations in the mudskipper (Periophthalmus papilio) fish, sediments, and water collected from the Ikpukulu, Kalio, and Ogoloma swamps of Okrika Local Government Area, Rivers State, Nigeria and analysed using standard methods. All samples were collected for six months from three stations in 2023. The results indicate that pH and temperature values were significantly lower across stations in terms of physicochemical properties than standards. However, there was a significant increase in electrical conductivity, total dissolved solids, and salinity. Ikpukulu had the highest EC (1917 uS/cm), while Kalio had the highest salinity (333.3 ppm). All stations had significant decreases in dissolved oxygen (DO) and biological oxygen demand (BOD), with Ogoloma having the lowest values (DO: 3.2 mg/L, BOD: 2.9 mg/L). Copper and chromium levels were significantly higher than the standards in all stations, while cadmium levels were not significantly different from those in the standards. As compared with the standards, copper levels in water samples were considerably higher, especially in Ogoloma (2.03 mg/kg). Ogoloma had a higher concentration of chromium. Cadmium levels decreased significantly at all stations for the mudskipper (P. papilio). The copper levels in Ogoloma and the chromium levels in Ikpukulu were significantly higher than those in standards. The results of the study suggest an increase in heavy metal concentrations in the mangrove swamp region, emphasising the need for proactive measures to mitigate activities that may adversely affect the aquatic ecosystem and the communities that depend on it.

Assessment of metals (Ni, Ba) deposition in plant types and their organs at Mersin City, Türkiye.

The increase in heavy metal concentrations in the air, especially after the Industrial Revolution, is notable for the scientific world because of the adverse effects that threaten environmental and human health. Among the trace elements, nickel (Ni) is carcinogenic, and all barium (Ba) compounds are toxic. Trace elements are critical for human and environmental health. Their threat further increases, especially in the urban areas and surroundings with a high population. In urban areas, the trace element contamination in the airborne can be reduced using plants. However, which plant and plant organs absorb trace elements could not be determined. In the present study, Ni and Ba concentrations in the branch, wood, and leaf samples of 14 species collected from the city center of Mersin province were determined. As a result, broad-leaved species' Ni and Ba concentrations in their leaf sample were generally higher than other species. Almost all species had the lowest Ni and Ba concentrations in their wood samples. Among these 14 species, it was found that Ni concentration was very high, especially in non-washed leaves of Platanus orientalis, Photinia serrulata, and Citrus reticulate, and Ba concentration was very high in Citrus reticulata, Chamaecyparis lawsoniana, Laurus nobilis, and Acer hyrcanum. Using broad-leaved species in urban areas where pollution is at high levels will significantly contribute to reducing Ni and Ba pollution. It is recommended that these points be considered in future urban landscaping projects.

Assessment of heavy metals in sediments and water accumulated by effects shipwrecks in Shatt Al-Arab River, southern Iraq

In this study, the total concentration of seven heavy metals (Cd, Cu, Fe, Pb, Mn, Ni, and Zn) in sediment and water was taken to determine how much the environment is impacted by rising levels of heavy metals that are not naturally occurring in five stations representing the large shipwrecks in Shatt Al-Arab River in Basra South Iraq by using atomic absorption. The heavy metals concentration in the five sediment stations is ordered as follows: Fe>Mn>Ni>Zn>Cu>Cd> Pb. While, the heavy metals concentration in the five water stations is ordered as follows: Fe>Ni>Mn>Cu>Pb>Zn>Cd. The current results of the study indicate that the concentrations of Cd, Fe, and Pb (slightly contaminated) metals in water are higher than the Iraqi standards (Iraqi standards for drinking water) and international standards (WHO, U.S. EPA, E.U.). An increase in heavy metal concentrations is attributed to the raw materials from which sunken ships are made near stations and these ships being exposed to military bombardment. The level of pollution in the sediment was assessed by employing the Geo accumulation index (I-geo), Contamination factor (CF), and Enrichment factor (EF). The calculated results of I-geo indicate that Cd can be considered to be moderate – strongly polluted except S5 considered strong to extremely polluted. However, Cu, Fe, Pb, Mn, Ni, and Zn showed almost unpolluted levels across all stations. The CF values indicate that this environment is very highly contaminated with Cd, while CF values for Cu, Fe, Pb, and Mn display low contamination. while CF values for Ni are moderate contamination except for S1 is low contamination. The pollution level for Zn is S1and S5 is low contamination and S2,3,4 is moderate contamination. The EF values refer to Cd at S5 indicating extremely severe enrichment and other stations refer to severe enrichment and minor enrichment for Fe, Mn, Ni, and Zn. Copper (Cu) has minor enrichment at S2 but no enrichment at the other stations. Conversely, Lead (Pb) shows no enrichment at any of the stations.

Plant Growth-Promoting Bacteria (PGPB): A Potent Source of Heavy Metal Stress Management in Plants

Heavy metals or metalloids are toxic elements found throughout the crust of the earth’s surface. The gradual increase of heavy metal concentration in soil and water due to some natural and anthropogenic activities like application of agrochemicals, waste disposal, industrial activities, mining, smelting, lead-based paints, etc cause stress to the local vegetation. Soil microorganisms play a critical part in the remediation of heavy metal contaminated soil and thereby exert direct or indirect promotion to plant growth. Plant growth-promoting bacteria (PGPB), specially the Plant growth-promoting rhizobacteria (PGPR), are a natural, sustainable, and eco-friendly solution for mitigating stress challenges. They can boost plant growth by alleviating heavy metal toxicity through various mechanisms such as metal sequestration, metal immobilization, and production of metal chelating compounds, which reduce metal toxicity and enhance plant growth. This review summarizes the effect of heavy metal stress on plants, the response of plants to heavy metal stress, mechanisms involved in metal stress tolerance by soil bacteria, and their application in managing heavy metal stress in plants.

Heavy metal transport with adsorption for instantaneous and exponential attenuation of concentration

Heavy metal pollutant is a serious problem in environmental pollution, and it is very difficult to eradicate once it enters the soil. As heavy metal adsorption has been proven to occur, the heavy metal’s behaviour can be modeled as a transport equation with adsorption. Previous adsorption term mostly due to the concentration alone, while in here, the desorption effect given by the rate of change of the concentration is also included. Also, the heavy metals are frequently considered to enter the soil after being dumped into the soil for a certain period of time. But, quick dumping onto the soil can introduce heavy metal instantaneously. Heavy metals entering the soil through leaching or when their concentration in the soil is influenced by chemical reactions, can all lead to the exponential decay of heavy metals entering the soil. Based on two-dimensional advection diffusion equation (ADE) with the new adsorption term, analytical solutions are obtained for the cases of instantaneous and exponential attenuation of heavy metals emission to soil by the method of Laplace transform. The results highlight the significant influence of emission type on the peak concentrations. If heavy metals are instantaneously enter the soil, the peak occurs in the range of 1–3 m radius from the point of emission on the first day, while for exponential attenuation the peak occurs close to the point of emission. Furthermore, there exists a correlation between retardation factors and heavy metal concentrations, where a decrease in retardation factors leads to an increase in heavy metal concentration. It is essential to investigate both types of heavy metals emission to provide valuable information for proper pollution management, effective environmental regulations and enforcement.

Purification of runoff pollution using porous asphalt concrete incorporating zeolite powder

Purification of urban runoff is of great significance for reducing the pollution of receiving water bodies and protecting the urban water environment. Zeolite powder is added to porous asphalt mixture in this study to improve the purification effect. The influence of zeolite powder on the road performance was evaluated to determine its optimal content. The effects of air void content, suspended solid (SS) concentration, heavy metal concentration, and rainfall intensity on the purification effect were studied and the purification durability was also analyzed. The experimental results show that the addition of zeolite powder has no obvious impact on road performance of porous concrete and can increase the removal rates of SS, chemical oxygen demand (COD), Zn2+, and Pb2+ by 6.4%, 25.2%, 20.6%, and 23.5%. The removal rates of SS, COD, Zn2+, and Pb2+ increase with the increase in SS concentration while the removal rate of heavy metals decreased with the increase in heavy metal concentration. Large air void content and rainfall intensity result in a decrease in the adsorption and purification effect. The removal rate shows a rapid decline since the sixth year, especially for SS, indicating that maintenance should be conducted at this time.

Two-Dimensional Heavy Metal Migration in Soil with Adsorption and Instantaneous Injection

This paper studies a two-dimensional transport model to investigate the behavior of heavy metal migration in porous media, specifically considering their transport in soil. The model takes into consideration the combination of adsorption term as well as instantaneous injection at the boundary. Also, the model accounts for both longitudinal and transverse movements, providing a comprehensive understanding of heavy metal transport phenomena. In order to obtain the analytical solution Laplace transform has been implemented. It is found that the peak concentration of heavy metals is found to be greatly affected by the changes in the instantaneous injection value. Additionally, a correlation is observed between retardation factors and heavy metal concentrations, with a decrease in retardation factors resulting in an increase in heavy metal concentration.

Study on the migration behaviour of heavy metals at the improved mine soil-plant rhizosphere interface

ABSTRACT With the increasing shortage of land resources and the aggravation of soil pollution in mining areas, the remediation of soil in abandoned mining areas has gradually attracted people's attention. The remediation of heavy metal contaminated soil in mining areas is the key to reduce the harm of heavy metals to the environment and human health. In this study, municipal sludge and phytoremediation technology were combined to investigate the migration and transformation of heavy metals at the soil-plant interface in improved mining areas through indoor pot experiments. The results showed that heavy metals in non-rhizosphere soil entered the rhizosphere environment with the growth of plants, leading to the increase of heavy metal content in rhizosphere soil. The cumulative amounts of Cu, Zn, Pb and Cd were 1299.32, 832.10, 347.89 and 71.34 mg/kg, respectively. The content of oxidized Cu and Zn decreased with increasing planting days, while the oxidized Pb and Cd showed an increasing trend. Under acidic conditions, H+ is easy to compete with heavy metal ions for exchangeable positions in the clay mineral layer, so that the reducible heavy metals are easy to be converted into exchangeable states. In this paper, the effects of various factors on the distribution of heavy metals were discussed by adjusting soil pH, adding humic acid and root exudates, so as to analyse the migration and transformation mechanism of heavy metals at the soil-plant interface, and provide a reliable theoretical basis for soil remediation in mining areas.

Anthropogenic increase of heavy metals in soil from a heavily contaminated area of China

ABSTRACT Evaluating the variation in heavy metal concentrations in soil caused by anthropogenic activities in heavily contaminated areas is of great significance. The degree of heavy metal pollution in soil is primarily assessed by different indices with different standards and reference elements. However, these methods cannot be used to evaluate the degree of heavy metal pollution caused by anthropogenic activities. In this study, Zhuzhou, China was selected as the contaminated area, and Yueyang, China was selected as the background area, where geological and climatic conditions are similar to those of Zhuzhou, China. The concentrations of As (6.6–23.6 mg/kg), Cd (0.125–0.757 mg/kg), Cu (33–75 mg/kg), Hg (0.032–0.202 mg/kg), Pb (17–108 mg/kg), and Zn (74–122 mg/kg) in the vertical soil profiles in the contaminated area were higher than those in the background area (ranging 1.7–20.7, 0.085–0.210, 21–47, 0.030–0.105, 17–38 and 32–88 mg/kg, respectively). K2O/Al2O3, SiO2/Al2O3, and the weathering leaching coefficient (ba) showed little difference, suggesting that the weathering degree of soil in these two areas was similar. The weathering degree of soil governs the geochemical behavior of heavy metals and reference elements. According to the prediction models for heavy metal concentrations and organic carbon, K2O/Al2O3, and SiO2/Al2O3 in the soil profiles from the background area, the increase in heavy metal concentrations in the topsoil in the contaminated area was depicted. The heavy metal concentrations in topsoil were obviously affected by anthropogenic activities. This study provides a case study for evaluating the impact of anthropogenic activities on heavy metals in soil.

Effect of heavy metals on germination, biochemical, antioxidant and withanolide content in Withania somnifera (L.) Dunal

Withania somnifera (L.) Dunal., commonly referred to as Ashwagandha, is a medicinal plant from the solanaceae family with a wide range of pharmacological properties. W. somnifera is a rich source of withanolides, such as withanolide A, withanolide B, withanolide D, withaferin A, etc. and these molecules are attributed for large number of pharmacological activities. In the present study, the impact of heavy metals such as cadmium (Cd), mercury (Hg), and lead (Pb) has been assessed on the growth, biochemical parameters, antioxidant activity and withanolide A and withaferin A content of W. somnifera. The seeds of W. somnifera were germinated in cocopeat treated with different concentrations of Cd (0–200 ppm), Hg (10–100 ppm), and Pb (0–2000 ppm) for 21 days. There have been substantial differences between the heavy metal-treated plants and the control plants with the lowest germination of 20% has been observed in the plants treated with 2000 ppm Pb. The selected metals inhibited vegetative growth with lowest length of 3.07 cm and lowest biomass of 0.74 g in 180 ppm Cd and 200 ppm Cd treated plants respectively. With the addition of heavy metals, biochemical parameters like protein, carbohydrate, chlorophyll, total phenol, flavonoid, and proline content varied significantly and showed metal tolerance by exhibiting antioxidant activity at lower concentrations. The metal accumulation occurred in a dose-dependent manner with highest Cd accumulation of 14.30 mg kg?1, Hg accumulation of 42.45 mg kg?1, and Pb accumulation of 217.46 mg kg?1 of dry biomass of the plants. The withanolide content increased up to a specific metal concentration and decreased with a further increase in heavy metal concentration. The seeds treated with 1200 ppm of Pb showed the highest withanolide A content of 1.7 mg g?1 DW, and the seeds treated with 80 ppm of Cd showed the highest withaferin A content of 3.2 mg g?1 DW.

The association between multi-heavy metals exposure and lung function in a typical rural population of Northwest China

Heavy metal exposure is acknowledged to be associated with decrease oflung function, but the relationship between metals co-exposure and lung function in rural areas of Northwest China remains unclear, particularly in an area famous for heavy metal pollution and solid fuel use. Therefore, the purpose of this study is to explore the effects of heavy metal exposure on lung function and the potential impacts of living habit in a rural cohort of Northwest China. The study area included five villages of two regions in Northwestern China-Gansu province. All participants were recruited from the Dongdagou-Xinglong (DDG-XL) rural cohort in the study area. Urine levels of 10 common and representative heavy metals were detected by ICP-MS, including Cobalt (Co), Nickel (Ni), Molybdenum (Mo), Cadmium (Cd), Stibium (Sb), Copper (Cu), Zinc (Zn), Mercury (Hg), Lead (Pb), and Manganese (Mn). The lung function was detected by measuring percentages of predicted forced vital capacity (FVC%) and predictedforced expiratory volume in one second (FEV1%) as well as the ratio of FEV1/FVC. We also analyzed the association between heavy metals and pulmonary ventilation dysfunction (PVD). Restricted cubic spline, logistic regression, linear regression, and bayesian kernel machine regression (BKMR) model were used to analyze the relationship between heavy metal exposure and lung function. Finally, a total of 382 participants were included in this study with an average age of 56.69 ± 7.32years, and 82.46% of them used solid fuels for heating and cooking. Single metal exposure analysis showed that the higher concentration of Hg, Mn, Sb, and lower Mo may be risk factors for PVD. We also found that FEV1% and FVC% were negatively correlated with Sb, Hg, and Mn, but positively correlated with Mo. The effect of mixed heavy metals exposure could be observed through BKMR model, through which we found the lung function decreased with the increase of heavy metal concentration. Furthermore, the males, BMI ≥ 24kg/m2 and who used solid fuels showed a higher risk of PVD when exposed to Co, Zn, and Hg. Our results suggested that heavy metal exposure was associated with decrease of lung function regardless of single exposure or mixed exposure, particularly for Sb, Hg, Mn and those who use solid fuels.

Three gorges dam shifts estuarine heavy metal risk through suspended sediment gradation

Damming alters downstream sediment supply relationships and erosion in the estuarine delta. Given that sediment grainsize serves as a key parameter for the ability to adsorb heavy metals from water, the assessment of estuarine heavy metal risk needs to get connected initially. Hence, fine suspended sediment (<63 μm) in the Yangtze River estuary (YRE) was divided into four grainsize fractions to simulate the surface suspended sediment concentration (SSC) and grainsize composition before and after the completion of the Three Gorges Dam (TGD). Representative months were selected for flood peak reduction (October) and runoff compensation in the dry season (March) to maximize the scheduling impact of the TGD on runoff and riverine sediment input to the YRE. An improved Water Quality Index (WQI) approach was proposed to assess the combined risk alteration of five heavy metals in six estuarine sensitive targets due to TGD-induced sediment characteristics. The results demonstrated that TGD significantly but tardily reduced the SSC and the proportion of fine sediment in the YRE, decreasing the risk of heavy metals resuspension. Seasonally, the total SSC became higher in the flood season than in the dry season during post-TGD period. However, the fine SSC in the flood season was averaged only 59.7% of that in the dry season due to the pronounced grainsize coarsening effect. As the significant reduction in fine SSC overcomes the increase in heavy metal content per unit of SS, the integrated resuspension risk declined significantly, particularly for Pb and Cr. Spatially, the risk reduction for sensitive targets near the turbidity maximum zone (TMZ) is 8.4 times greater than for inner river channel. However, undiminished anthropogenic metal inputs to the YRE signified greater pressures on the depositional environment.

High volume waste foundry sand self-compacting concrete – Transitioning industrial symbiosis

In light of massive industrialization, Industrial symbiosis has gained traction by most countries to employ wastes of one industry as a resource to another. Waste foundry sand obtained from the metal casting industry is a threat to the environment and the health of living beings due to the presence of organic and inorganic materials. However, this waste can be a resource for the construction industry. Despite its broad application scope, usage of waste foundry sand is highly limited due to inadequate understating of its performance in concrete. It becomes essential to understand the behaviour of waste foundry sand in concrete, more importantly, for accessing a strength-efficient and durable structure. The concrete samples were examined by conducting a number of experiments to investigate ties between strength, durability and microscopic insights. It has been observed that the inclusion of waste foundry sand can improve strength properties at later ages. Particular attention is paid to study the detailed microstructural investigations conducted on the concretes having up to 50% waste foundry sand. In addition, a leaching analysis was performed that revealed an increase in heavy metal concentration with the increasing WFS content. However, its concentration was below the acceptable limit, as evidenced by USEPA. Mineral and compositional characteristics monitored the effect of calcium aluminosilicate in the concrete matrix from early to later ages by X-ray diffraction and energy dispersive spectrometer analysis for the solid constituents of the concrete specimen, respectively. In light of the above, this study reveals that the strength properties of blended SCC were improving at later ages; significant improvement was discovered after 91 days of curing time. The compressive strength results were observed to increase by 16.6% for the specimens containing 40% waste foundry sand relative to control concrete at 91 days. The highest strength properties were achieved at 365 days, with 50% replacement ratios of waste foundry sand. The values for UPV were observed to improve as the curing age increases with the reduction in the rate of carbonation resistance of concrete. The carbonation depth was observed to be less than 1 mm for specimens containing 40% and 50% waste foundry sand for accelerated and atmospheric carbonation at 56 days and 2 years, respectively. The originality of the study relies on the possibility of developing waste foundry sand-self compacting concrete with the maximum utilization of waste foundry sand, achieving the targeted results. The study showed a good agreement between the waste foundry sand and concrete that creates a ground for the enhanced application of industrial symbiosis.

Simultaneous removal of multiple heavy metals using single chamber microbial electrolysis cells with biocathode in the micro-aerobic environment

The simultaneous and efficient removal of various heavy metals from wastewater to satisfy the requirements of zero discharge has been a research hotspot and difficult point. In the laboratory scale (0.5 L), the biocathode microbial electrolytic cells (BCMECs) were constructed with the pre-screened heavy metal-tolerant electroactive bacterial, mainly of the Sphingomonas, Azospira and Cupriavidus. The BCMECs system showed a more satisfactory removal effect for multiple heavy metals and organic pollutants. At the auxiliary voltage of 0.9 V and initial concentration of 20 mg L−1, the removal efficiency of Cu, Pb, Zn, Cd and COD were 98.76 ± 0.32%, 98.01 ± 0.76%, 73.58 ± 4.83%, 84.39 ± 5.95%, 77.55 ± 1.51%, respectively. It was found by various characterization techniques (CV, EIS, XPS et al.) that the constructed biocathode has the function of electrocatalytic reduction of heavy metal ions in a micro-aerobic, film-free environment. The positive shift (0.030–0.229 V) of the initial potential for heavy metal reduction and the absence of a significant increase (＜ 10 Ω) in the interfacial resistance indicated a reduction in the total free energy of the reduction reaction, which promotes the reaction and improves the efficiency of heavy metal removal. Bacterial community analysis revealed that the Proteobacteria has been dominant in different heavy metal environments. With the increase of heavy metal concentration, Sphingomonas, Azospira and Cupriavidus showed stronger tolerance and became the dominant genus. This study emphasized the important performance of biocathodes and the effective treatment of heavy metal wastewaters by BCMECs and provided a reasonable way for industrial and mining enterprises to innovate the water treatment process.

Detoxification of Selenium Yeast on Mycotoxins and Heavy Metals: a Review.

Mycotoxins are secondary metabolites produced by specific fungi. More than 400 different mycotoxins are known in the world, and the concentration of these toxins in food and feed often exceeds the acceptable limit, thus causing serious harm to animals and human body. At the same time, modern industrial agriculture will also bring a lot of environmental pollution in the development process, including the increase of heavy metal content, and often the clinical symptoms of low/medium level chronic heavy metal poisoning are not obvious, thus delaying the best treatment opportunity. However, the traditional ways of detoxification cannot completely eliminate the adverse effects of these toxins on the body, and sometimes bring some side effects, so it is essential to find a new type of safe antidote. Trace element selenium is among the essential mineral nutrient elements of human and animal bodies, which can effectively remove excessive free radicals and reactive oxygen species in the body, and has the effects of antioxidant, resisting stress, and improving body immunity. Selenium is common in nature in inorganic selenium and organic selenium. In previous studies, it was found that the use of inorganic selenium (sodium selenite) can play a certain protective role against mycotoxins and heavy metal poisoning. However, while it plays the role of antioxidant, it will also have adverse effects on the body. Therefore, it was found in the latest study that selenium yeast could not only replace the protective effect of sodium selenite on mycotoxins and heavy metal poisoning, but also improve the immunity of the body. Selenium yeast is an organic selenium source with high activity and low toxicity, which is produced by selenium relying on the cell protein structure of growing yeast. It not only has high absorption rate, but also can be stored in the body after meeting the physiological needs of the body for selenium, so as to avoid selenium deficiency again in the short term. However, few of these studies can clearly reveal the protective mechanism of yeast selenium. In this paper, the detoxification mechanism of selenium yeast on mycotoxins and heavy metal poisoning was reviewed, which provided some theoretical support for further understanding of the biological function of selenium yeast and its replacement for inorganic selenium. The conclusions suggest that selenium yeast can effectively alleviate the oxidative damage by regulating different signaling pathways, improving the activity of antioxidant enzymes, reversing the content of inflammatory factors, regulating the protein expression of apoptosis-related genes, and reducing the accumulation of mycotoxins and heavy metals in the body.

Linking Measure of the Tropical Stingless Bee (Apidae, Meliponini, and Heterotrigona itama) Honey Quality with Hives Distance to the Source of Heavy Metal Pollution in Urban and Industrial Areas in Sabah, Borneo.

Honey is a natural product of bees, and its chemical composition depends on the nectar sources of the surrounding flora as well as environmental factors. However, keeping hives in areas polluted with heavy metals can affect the quality of bee products such as honey. To date, there have been very few studies on the health risks of consuming honey at various locations in the Malaysian state of Sabah, Borneo, in relation to food standards and heavy metal contamination of honey from the stingless bee, Heterotrigona itama in association with pollutant sources. A total of 63 samples of raw and unprocessed honey were collected directly from beekeepers producing honey at five sites in the industrial areas. All selected heavy metals were measured using an inductively coupled plasma optical emission spectrophotometer (ICP-OES). Overall, the most frequently detected element was Zn (0.090 mg/kg), followed by Pb (0.012 mg/kg), As (0.004 mg/kg), and Cr (0.003 mg/kg), while Cd (0.001 mg/kg) was the lowest element in honey from all areas. With the exception of Cr and Zn, a significant correlation was found between PCA factor score 1 and heavy metal concentration in honey for Pb, Cd, and As, suggesting that the source of pollution for these metal elements was from hives closer to major roads, cities/town, petrochemical hub, and power plants. Although the heavy metal concentrations in the honey samples did not exceed the food standard limits and therefore do not pose a health risk, the observed increase in heavy metal concentrations in honey in industrial areas could pose a potential risk in the future due to the growing interest in rearing of stingless bees for honey production in these areas of Sabah.

Occurrence and Uptake of Heavy Metals in Soil and Plant (Tomato) Associated with Crude Oil Contamination

The general increase of heavy metal content in the soil has been largely caused by crude oil spillage. This study investigates the possibility of tomato (Lycopersicon esculentum Miller) to sorb heavy metals present in crude oil. Crude oil of 0 mL (control), 75 and 150 mL were mixed thoroughly with 15 kg of loamy soil (dry weight) in perforated plastic buckets, as the experimental pots and left for 4 days before transplanting tomato seedlings. After 12 weeks of transplanting, heavy metals analysis was carried out on plant’s fruits, leaves, stems and roots. Physicochemical analyses show that control soil had the lowest organic carbon (3.07 %) while 150 mL had the highest mean organic carbon content (8.24 %). The silt, clay and sand constituents were not significantly different (p &gt; 0.05) in both treated and untreated soil. The control had the least pH value (6.1) while the lead (Pb) content in soil was highest in 150 mL (0.33 mg/kg) but was not significantly different (p &gt; 0.05) from control (0.26 ) and 75 mL (0.30 mg/kg). Lead (Pb) and Cadmium (Cd) were not detected in leaves and fruits. However, bioaccumulation factor (BAF) of Cd and Ni in stem were greater than 1. Although, the concentrations of these heavy metals falls below toxic levels, its consumption could lead to adverse health effects in both man and animals through bioaccumulation or biomagnification.&#x0D; HIGHLIGHTS&#x0D; &#x0D; Countries with poor hydrocarbon pollution regulation are more challenging with oil spills, either through accidental discharges or indiscriminate disposal of hydrocarbon waste&#x0D; Plants essentially need some metals such as iron, copper among others, for their growth and other metabolic activities. However, at excess of specific limits, these metals adversely affect plant growth&#x0D; In this study, bioaccumulation factors (BAF) of Cd and Ni in the stem were greater than 1, this shows that the tomato plant is a hyperaccumulator of Cd and Ni from the soil&#x0D; &#x0D; GRAPHICAL ABSTRACT

Leaching of chromium and lead from the cement mortar lining into the flowing drinking water shortly after pipeline rehabilitation

Internal cement lining protection is used for both new and renovation of old cast iron water pipes. However, under unfavorable conditions, contaminants may be released from the cement lining into the drinking water shortly after the rehabilitation of old or installation of new water pipes. This paper proposes a mathematical model for the leaching of heavy metals from the inner cement lining of the pipe into the flowing water, taking sorption into account. Previously, mathematical models described in the literature for the leaching of contaminants from a cement coating into water only addressed static conditions or did not consider sorption. Experimental verification of the mathematical model under dynamic conditions showed very good agreement between calculated and measured results and confirmed the necessity of taking into account the sorption phenomenon. It also demonstrated the need for periodic water changes during laboratory experiments to describe the release of contaminants from the cement coating into the flowing water. Based on the results of laboratory experiments and the developed mathematical model, the concentrations of heavy metals at the ends of different lengths of drinking water supply pipeline sections after their eventual rehabilitation by cementation were calculated. Maximum lead concentrations at the end of 30, 23 and 13-km cemented sections of the pipeline were 2.0; 1.5 and 1.0 mg/m 3 , respectively. In contrast, chromium concentrations were 2.5; 1.6 and 0.9 mg/m 3 , respectively. Although all of these values are below the drinking limits, they can reach them if there is another additional source of contaminants or if the water stagnates periodically. The developed methodology and mathematical model allow to select the maximum length of the water main section that can be renovated or replaced at one time without significant impact on drinking water quality. • Modeling the leaching of heavy metals from an internal cement coating into flowing drinking water. • Significant effect of concentration gradient at the water-cement interface on metal leaching intensity. • Slight increase in heavy metal concentrations in drinking water flowing through newly cement-lined pipeline.