Lead Concentrations Research Articles

Accumulation of heavy metals (Cr, Cu, As, Cd, Pb, Zn, Fe, Ni, Co) in the water, soil, and plants collected from Edayar Region, Ernakulam, Kerala, India

The accumulation of heavy metals in the environment is a significant concern due to their potential toxicity and persistence. This study investigates the levels of heavy metal contamination in the water, soil, and plants of the Edayar region in Ernakulam, Kerala, India. The region has experienced industrialization and urbanization, leading to concerns about heavy metal pollution. The study aims to assess the concentrations of chromium (Cr), copper (Cu), arsenic (As), cadmium (Cd), lead (Pb), zinc (Zn), iron (Fe), nickel (Ni), and cobalt (Co) in water, soil, aquatic and terrestrial plants. Samples were collected from various locations within the Edayar region, and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was conducted to quantify heavy metal concentrations. The findings of this study will contribute to the assessment of heavy metal pollution in the Edayar region. Plants with a high diversity index were taken for analysis from both aquatic and terrestrial habitats. Scoparia dulcis L. seems to specialize in metal accumulation, possibly for protective purposes. Synedrella nodiflora Gaertn demonstrates adaptability to metal-rich environments through robust metal uptake and tolerance mechanisms. Alternanthera philoxeroides (Mart.) Griseb, on the other hand, appears to have developed mechanisms to manage heavy metal exposure. The results indicate significant levels of heavy metal contamination across all samples, with the highest concentrations detected in soil, followed by water and plants. Chromium and lead levels in soil exceeded the permissible limits set by international standards, posing potential risks to human health and the ecosystem. The accumulation patterns in plants varied, with higher bioaccumulation factors observed for zinc and copper, suggesting their preferential uptake. This study highlights the urgent need for remediation strategies and continuous monitoring to mitigate the impact of heavy metal pollution in the Edayar region. The results will help in understanding the environmental impact of human activities.

Exposure to Lead (Pb) influences the outcomes of male-male competition during precopulatory intrasexual selection

Male-male competition is a component of Darwin’s theory of precopulatory intrasexual selection, where males compete for access to resources important for reproduction and successful males pass on traits that endow greater competitive ability to their offspring, thereby exaggerating the trait(s) over evolutionary time. Metals, such as lead (Pb) often occur in urban mangrove forests, where shore crabs reside, and being neurotoxic may cause sub-lethal effects on behaviour. In this study, we asked whether exposure to Pb influences the outcomes of male-male competition in the Semaphore crab, Heloecius cordiformis, thereby altering outcomes of intrasexual selection. Crabs were exposed to an environmentally relevant, and a behaviourally relevant, concentration of lead (i.e. Pb, 10 µg/L and 100 µg/L respectively) under laboratory conditions for 96 h and subsequently allowed to compete for burrow ownership in experimental arenas. Exposed crabs (100 µg/L) were less successful than control crabs in chela size-matched paired competitive interactions, spent less time in burrows and predominantly lost burrow ownership. Further, exposure to Pb contamination (both 10 µg/L and 100 µg/L) negated the chela size advantage in size-asymmetric competitive interactions. This contaminant-induced loss of size-related competitive advantage may result in relaxation in selection pressure on body size and smaller male carapace widths and especially male chela lengths in contaminated locations. Assessment of a range of locations in the wild found a consistent pattern of metal-associated size declines in more contaminated locations for males, but not for females.

Human biomonitoring of essential and toxic trace elements (heavy metals and metalloids) in urine of children, teenagers, and young adults from a Central European Cohort in the Czech Republic.

Exposure to toxic trace elements, which include metals and metalloids, can induce adverse health effects, including life-threatening diseases. Conversely, essential trace elements are vital for bodily functions, yet their excessive (or inadequate) intake may pose health risks. Therefore, identifying levels and determinants of exposure to trace elements is crucial for safeguarding human health. The present study analyzed urinary concentrations of 14 trace elements (arsenic, cadmium, cobalt, chromium, copper, mercury, manganese, molybdenum, nickel, lead, antimony, selenium, thallium, and zinc) and their exposure determinants in 711 individuals, spanningfrom children to young adults from a Central European population from the Czech Republic. Multivariate linear regression and non-parametric Kruskal-Wallis ANOVA were used to investigate exposure determinants. Estimates of 95th percentile concentrations and confidence intervals were carried out to establish reference values(RV95). The study also assessed the percentage of population exceeding health-based guidance values (GVs) to gauge health risks. Young adults showed elevated toxic element concentrations, whereas children exhibited higher concentrations of essential elements. Mercury concentrations were associated with both dental amalgam filling count and seafood intake; arsenic concentrations were associated with seafood, rice, and mushroom consumption. Mushroom consumption also influenced lead concentrations. Sex differences were found for cadmium, zinc, nickel, and cobalt. Between 17.9% and 25% of the participants exceeded recommended GV for arsenic, while 2.4% to 2.8% exceeded GV for cadmium. Only one participant exceeded the GV for mercury, and none exceeded GVs for chromium and thallium. Essential trace elements' GVs were surpassed by 38% to 68.5% participants for zinc, 1.3% to 1.8% for molybdenum, and 0.2% to 0.3% for selenium. The present study examines trace element exposure in a Central European population from the Czech Republic, unveiling elevated exposure levels of toxic elements in young adults and essential elements in children. It elucidates key determinants of trace element exposure, including dietary and lifestyle indicators as well as dental amalgam fillings. Additionally, the study establishes novel reference values and acomparison with established health-based human biomonitoring guidance values, which are crucial for public health decision-making. This comprehensive biomonitoring study provides essential data to inform public health policies and interventions.

Assessing the impact of leachate irrigation on Medicago sativa (alfalfa) growth, enzymatic responses, and heavy metal accumulation.

In light of the increasing water scarcity and the need for sustainable waste management, the use of landfill leachate for irrigation has emerged as both a solution and a concern, posing potential risks to soil health and plant vitality. This study examined the multifaceted impacts of leachate irrigation on the soil characteristics, plant growth, and enzymatic activities of Medicago sativa (M. sativa). By exposing alfalfa to different concentrations of leachate, we assessed the influence on heavy metal accumulation, physiological parameters, and enzyme functions. The physicochemical profile of the leachate indicated that the pH was within acceptable limits, but the chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and concentrations of lead (Pb) and aluminum (Al) exceeded regulatory standards. Morphological parameters exhibited dual effects: stimulation at lower leachate doses and inhibition at higher leachate doses. Our findings show that soil acts as a buffer, reducing heavy metal uptake by plants. Enzymatic activities, including catalase, peroxidase, and succinate dehydrogenase, fluctuated significantly at higher leachate concentrations, indicating stress responses. This research underscores the interplay between leachate irrigation, plant physiology, and soil health, emphasizing sustainable management to optimize plant growth and minimize environmental impacts. It also stresses refining leachate application protocols to preserve soil and ecosystem health.

Determination of concentration and risk assessment of toxic metals in the settled dust from school yards of Mashhad metropolis.

The present study aims to measure the values of metal pollutants in the dust of schools in Mashhad metropolis, determine the source of metal pollution, evaluate the degree of pollution, assess the health risk (carcinogenicity/non-carcinogenicity) and evaluate the potential ecological risk. For this purpose, after measuring the concentration of metals using an inductively coupled plasma-mass spectrometer, from various indices including Geoaccumulation Index (Igeo), Pollution Load Index (PLI), Contamination Factors (CF), Potential Ecological Risk Index (PERI), Enrichment Factor (EF), and Health Risk Indices such as Hazard Quotient (HQ), Hazard Index (HI), Carcinogenic Risk (CR) were used. The average concentrations of iron, arsenic, cadmium, chromium, copper, nickel, lead, vanadium and zinc (Fe, As, Cd, Cr, Cu, Ni, Pb, V and Zn) were 6361.50, 5.96, 0.59, 61.89, 37.13, 61.31, 28.93, 25.64 and 142.00µgg-1, respectively. Based on CF, PLI and Igeo indices, most of the findings for the studied elements were at the low pollution level. The results also showed that the most likely origin of the studied metals was anthropogenic sources. The results of PERI indices showed that potential ecological risk at only one of the collection sites. In contrast, a high ecological risk was obtained for Cd. Hazard Index values were below safe levels for all studied elements. CR levels for elements were also classified as negligible and acceptable or tolerable risk, although the highest CR value for Cr indicated possible harm to humans. The findings showed the need for more attention and continuous monitoring of the concentration of metals, especially chromium, to announce a possible warning and prevent their harmful effects. It should be noted that the present study is the first research with mentioned objectives in Mashhad city and also in Khorasan Razavi province.

Biomonitoring of Mercury and Lead Levels in the Blood of Children Living near a Tropical River Impacted by Artisanal and Small-Scale Gold Mining in Colombia.

(1) Background: Mercury and lead contamination resulting from various anthropogenic activities represents a global environmental problem and a considerable risk to the health of the human population. (2) Methods: The objective of this research was to evaluate the concentrations of mercury (Hg) and Lead (Pb) in the blood of the child population in the municipalities in the Atrato River basin using a direct Hg analyzer and graphite furnace atomic absorption spectrometry. (3) Results: In total, 171 children (5-14 years of age) were taken into account, and 18.71% (32) of the children had concentrations of Hg and Pb above the permissible values established by the WHO. In the municipality of UN, 19 children had blood Hg concentrations between 5.29 and 17.71 μg/L. In CA, two children had concentrations of 5.03 and 8.43 μg/L, separately. In the case of Pb, seven children showed concentrations between 3.60 and 4.83 μg/dL in the municipality of RQ, three in UN (3.59, 3.61, and 4.60 μg/dL), and one in Carmen de Atrato (5.47 μg/dL). (4) Conclusions: The levels of Hg and Pb in the blood of children living in the riparian areas of the Atrato River basin are related to gold mining activities in the basin and the consumption of contaminated fish.

Investigating the Spatial Patterns of Heavy Metals in Topsoil and Asthma in the Western Salt Lake Valley, Utah

Mining activities, particularly in large excavations like the Bingham Canyon Copper Mine in Utah, have been increasingly linked to respiratory conditions due to heavy-metal-enriched waste and dust. Operating continuously since 1906, the Bingham Canyon Copper Mine contributes 4.4% of the Salt Lake Valley PM2.5 pollution. However, the extent of its contributions to larger-sized particulate matter (PM10) dust, soil and water contamination, and human health impacts is largely unknown. Aerosol optical depth data from Sentinel-2 imagery revealed discernible dust clouds downwind of the mine and smelter on non-prevailing-wind days, suggesting potential heavy metal dispersion from this fugitive dust and subsequent deposition to nearby surface soils. Our analysis of topsoils from across the western Salt Lake Valley found mean arsenic, copper, lead, and zinc concentrations to be well above global background concentrations. Also, the minimum values for arsenic and maximum values for lead were well above the US EPA regional screening levels for residential soils. Thus, arsenic is the metal of greatest concern for impacts on human health. Elevated concentrations of all metals were most notable near the mine, smelter, and tailings pond. Our study linked these elevated heavy metal levels to regional asthma outcomes through cluster analysis and distance-related comparison tests. Significant clusters of high asthma rates were observed in regions with elevated topsoil heavy metal concentrations, impacting both low- and high-income neighborhoods. The findings of this preliminary study suggest that the mine, smelter, and recent construction activities, especially on lands reclaimed from former tailings ponds, could be contributing to atmospheric dust containing high levels of heavy metals and exacerbating asthma outcomes for residents. However, the methods used in the study with aggregated health outcome data cannot determine causal links between the heavy metal contents of soil and health outcomes; they can only point to potential links and a need for further investigation. Such further investigation should involve individual-level data and control for potential confounding factors, such as socioeconomic status, access to healthcare, and lifestyle factors, to isolate the effect of metal exposures on asthma outcomes. This study focused on atmospheric deposition as a source of heavy metal enrichment of topsoil. However, future research is also essential to assess levels of heavy metals in subsoil parent materials and local surface and groundwaters to be able to assess the links between the sources or methods of soil contamination and health outcomes.

Impact of ceramic packaging on the quality and safety of Armenian fermented dairy product Matsoun

Background: Packaging is essential for food safety, as it acts as a barrier against contaminants that can cause spoilage and affect human health. The Armenian fermented dairy product, matsoun, is packaged not only in plastic and glass but also in clay pots. However, the impact of traditional packaging on the quality and safety of matsoun, especially heavy metal migration, remains under-researched. Objective: This study aimed to investigate the impact of ceramic packaging material on the quality and safety of matsoun during storage. Specifically, it compared the physicochemical properties (pH, titratable acidity), lactic acid bacteria (LAB) populations, and metal migration during storage. Methods: Six samples of matsoun were prepared and packaged in sterilized glass and ceramic containers. The samples were stored at 4 °C and analyzed on days 1, 7, and 15 of storage. The parameters measured included pH, titratable acidity, and LAB counts (coccus and bacillus). Heavy metal migration (Cd, Pb, Hg, As) was analyzed using atomic absorption spectroscopy. Results: The pH of samples packaged in ceramic and glass containers decreased over 15 days of storage, from 4.61 to 4.24 and 4.6 to 4.27, respectively. Titratable acidity increased in both groups, reaching 1.2 % lactic acid. A decrease in bacilli was observed in ceramic-packaged matsoun. The lead concentration remained constant at 0.0045 ppm across all samples. In ceramic containers, cadmium concentration increased from 0.0015 ppm to 0.0029 ppm by day 15. Conclusion: This study observed a decrease in pH, an increase in titratable acidity, and a relatively constant number of lactic acid bacteria indicating ongoing fermentation. The results showed nondetectable concentrations of arsenic (As) and mercury (Hg). The lead (Pb) concentration in all samples remained within the World Health Organization’s (WHO) allowed limit of 0.02 ppm. However, the concentration of cadmium (Cd) concentration in ceramic-packed increased, exceeding the WHO limit of 0.002 ppm. Further research is necessary to identify the sources of cadmium contamination. Keywords: food packaging, ceramic, matsou​​n​, heavy metal migration, food safety

Evaluation of the water quality of an artificial inter-andean lake in northern Peru

Lake Burlan, a lentic ecosystem artificially created by untreated runoff from adjacent rice fields, is located in the Amazon region within the dry forests of northern Peru. This body of water plays a fundamental role in agriculture and recreational activities in the area, which are fundamental to the local economy. This research aimed to evaluate the water quality of Lake Burlan using the Water Quality Index of Peru (WQI-PE). In addition, both spatial and depth variations of limnological parameters and trace elements were determined. The WQI-PE was calculated at seven sampling stations at two depths (surface level and one meter), using 18 limnological parameters and nine trace elements. The WQI-PE assessment indicated that the lake water quality ranged from poor to fair for both depths. Statistical analysis showed that nine limnological parameters and five trace elements showed spatial differences across seven sampling stations, while three limnological parameters and two trace elements showed depth-dependent variations. Concentrations of arsenic, cadmium, mercury, and lead were in exceedance of the national and international standards on environmental water quality. Therefore, the water quality of Lake Burlan is affected mainly by the impact of the surrounding rice fields and recreational activities. This research establishes a starting point for future monitoring to assist in the implementation of prevention and mitigation.

Assessing the potential ecological and human health risks of trace metal pollution in surface water, sediment, and commercially valuable fish species in the Pashur River, Bangladesh.

This research examines the contamination levels in the Pashur River in Bangladesh stemming from trace metal discharge originating from the Mongla seaport and various industrial outlets. It delves into both ecological risks and potential health hazards for humans consuming fish carrying accumulated trace metals. The research employed atomic absorption spectrometry to measure the concentrations of chromium (Cr), arsenic (As), manganese (Mn), copper (Cu), zinc (Zn), nickel (Ni), lead (Pb), and cadmium (Cd) in surface water, sediment, and fish samples. Target hazard quotient (THQ) and carcinogenic risks were calculated to determine the human health risk caused by the consumption of these targeted fish species. An RI value of 42.89 indicates that the collective presence of trace metals in sediment poses significant ecological risks to the study area. Although the majority of trace metals present in sediment are categorized under class 1 (ranging from unpolluted to moderately polluted) based on the Igeo values, Cd is classified under class 2, signifying a moderate level of pollution. Significantly, THQ values surpass the threshold of 1 for Cr and As, indicating potential health risks associated with the consumption of specific fish species. Among the trace metals analyzed, Ni demonstrates the highest cancer risk (CR) value, at 5.78 × 103, indicating a notable cancer risk associated with the consumption of targeted fish. Recommendations include the strict enforcement of waste disposal policies to mitigate anthropogenic discharge and safeguard the river from further pollution.

Biomarkers of Nicotine and Toxicant Exposure by E-liquid Nicotine Concentration Level among U.S. Adult Exclusive E-cigarette Users.

The current e-cigarette market has been rapidly evolving with an increase in the share of high nicotine concentration vaping products. This study examined urinary biomarkers of exposure (BOEs) by nicotine concentration level among exclusive e-cigarette users. Data were drawn from Wave 5 (December 2018-November 2019) of the Population Assessment of Tobacco and Health (PATH) Study. Between-subject differences in BOEs of nicotine, metal, tobacco-specific nitrosamine (TSNA), and volatile organic compounds (VOC) were examined across e-cigarettes containing nicotine or not (yes [n=300] vs. no [n=31] vs. non-tobacco use [n=3021]) and different nicotine concentration levels (0.1-1.7%, 1.8-4.9%, and 5.0%+). Among 3353 participants, exclusive e-cigarette users exhibited higher mean concentrations of nicotine metabolites than non-tobacco users. Nicotine e-cigarette users had higher concentrations of TNE2 (mean [95% CI]=21.8 [15.2-31.2] vs. 0.2 [0.1-0.6] nmol/mg creatinine, p<.0001) and cotinine (1418.2 [998.0-2015.4] vs. 12.2 [0.1-0.6], p<.0001) ng/mg creatinine, p<.0001) than non-nicotine e-cigarette users. Users of e-cigarette products with nicotine levels of 1.8-4.9% had higher TNE2 and cotinine levels than those using 0.1-1.7%, though differences were insignificant after adjusting for covariates. As compared to non-tobacco users, nicotine vapers had higher concentrations of lead (adjusted p=0.01). Nicotine containing e-cigarette users exhibited elevated levels of nicotine metabolites than non-nicotine containing vapers and non-tobacco users. Future research needs to investigate health effects of e-cigarette use across different nicotine levels Impact: Regulating the nicotine content in e-cigarettes could be crucial in managing nicotine exposure and potentially mitigating associated health risks.

Remediation quantum of organic amendments to immobilize potentially toxic heavy metals in wastewater-contaminated soils through maize cultivation

Wastewater is considered a good reservoir of mineral elements that can be used for agriculture, aquaculture, and some other activities after adopting suitable measures. The gap between supply and demand for water is increasing exponentially because of the abrupt boost to the world’s population. This poses a threat to human life as it has reached alarming levels in some parts of the globe. Normally, wastewater consists of liquid waste produced by commercial or industrial sources for daily use, consumption, and production. It is time to refocus our attention on a kind of circulating water system by reusing municipal wastewater for agricultural purposes, particularly irrigation. The recycled or treated water would be used as an alternative to fresh water. In the current study, the impact of various organic amendments was studied to mitigate the toxic effects of pollutants present in wastewater by cultivating maize as a test crop. The present study comprised five treatments replicated four times with a randomized complete block design under field conditions. In this experiment, the treatments included T1 (treatment 1) = control (wastewater-polluted soil without the application of any amendment), T2 = farmyard manure (FYM) at 2.5 tons ha-1 (hectare-1), T3 = FYM at 5.0 tons ha-1, T4 = compost at 2.5 tons ha-1, and T5 = compost at 5.0 tons ha-1. The application of FYM at 5.0 tons ha-1 (T3) was recorded as being the most effective as the maximum improvement was observed in soil characteristics such as pH, electrical conductivity (EC), sodium adsorption ratio (SAR), and organic matter, and for T3, these were 7.33, 2.22 dS m-1, 8.16, and 0.94%, respectively. T3 remained most superior in reducing the concentration of heavy metals in the soil; for example, lead, cadmium, nickel, and arsenic for T3 were 8.64, 1.34, 10.44, and 2.25 mg kg-1 (milligrams per kg), respectively. Maximum fresh biomass (fodder yield) of 9.98 tons ha-1 was harvested when FYM was applied at 5.0 tons ha-1 to the soil compared to 6.2 tons ha-1 in the control plot. The highest contents of nitrogen (1.20%), phosphorus (0.41%), and potassium (3.97%) were observed in maize plants for T3. In maize plants (T3), the concentration of lead, cadmium, nickel, and arsenic was reduced to levels of 1.92, 0.23, 2.28, and 1.25 mg kg-1, respectively. Therefore, it can be concluded from the findings of the experiment that the application of FYM significantly reduced heavy metal concentrations and improved soil health, along with maize crop growth and productivity.

Health risk assessment of lead and cadmium exposure from food and snuff in Pakistani population

BackgroundSmokeless tobacco (SLT) is a tobacco-based product consumed without burning or smoking. Snuff, commonly known as naswar, is a widely used SLT product in Pakistan. This study is designed to investigate the concentrations of lead (Pb) and cadmium (Cd) in snuff and their associated health risks to consumers. MethodsBlood samples from snuff consumers and non-consumers were analyzed for Pb and Cd concentrations. Additionally, samples of drinking water and wheat flour were also analyzed for Pb and Cd. Health risk assessments were calculated using hazard quotient (HQ) and incremental lifetime cancer risk (ILCR) for Pb and Cd. ResultsSnuff consumers had significantly higher blood-Pb and blood-Cd levels compared to non-consumers. Approximately 38.5 % of snuff consumers were found to exceed blood-Pb levels from the safe limits (10 µg dL⁻¹) of the World Health Organization (WHO), while 48.9 % of snuff consumers were found to exceed blood-Cd levels from the WHO safe range of 0.03–0.12 µg dL⁻¹. Snuff samples contained Pb and Cd concentrations ranging from 5.3 to 22.4 µg g⁻¹ and 0.5–2.2 µg g⁻¹, respectively. Drinking water and wheat flour samples were found within the safe limits for Pb and Cd concentration, suggesting snuff as the primary source of exposure. Health risk assessments indicated elevated HQ values, for Pb (38.9 %) and Cd (14.3 %) detected in snuff, surpassing the safe HQ threshold of 1. Concerning ILCR from snuff, values for Pb were within the acceptable range, but alarmingly 100 % of samples for Cd exceeded the safe limits of USEPA (1.0×10⁻⁴), indicating a significant cancer risk in snuff users. ConclusionThis study highlights the exceeded Pb and Cd concentrations in snuff as well as also reporting significant carcinogenic and non-carcinogenic health risks to consumers. These findings emphasized the urgent need for regulatory bodies to ensure the safety of snuff before selling in the market. Public Health Professionals should also initiate educational campaigns to raise awareness among consumers and manufacturers about various health risks associated with the snuff.

Potentially Toxic Metals Enrichment in Soils of Ishiagu Mining Community, Southeastern Nigeria

This Study was carried out to evaluate potentially toxic metals enrichment, pollution and potential ecological risk in the soils of Ishiagu. The concentrations of Cadmium (Cd), Chromium (Cr), Cobalt (Co), Copper (Cu), Lead (Pb), Manganese (Mn), Nickel (Ni), Zinc (Zn), Aluminum (Al) and Iron (Fe) in soil samples from the area were analyzed by Bureau Veritas Laboratory, Vancouver, Canada, using inductively-coupled plasma optic emission spectrometry (ICP-OES). Descriptive statistics, enrichment factor, pollution load and potential ecological risk indices were employed to analyze the data in order to understand the characteristics of potentially toxic metals in the study area. The potentially toxic metals statistic show the mean values (mg/kg-1 ) of Pb, Zn, Mn, Fe, Al, Cd, Cr, Ni, Co, and Cu to be 205.7, 162, 527, 35892, 11374, 1.3, 21.6, 15, 14.6 and 11.1 respectively. The soil enrichment varied considerably between mining and non-mining areas with mining area being extremely enriched with Pb, Zn and Cd, and significantly enriched with Co, Cu, Ni and Fe. Non- mining areas are minimally enriched with all investigated metals. The soils around the mines are polluted with Pb and Cd, where both metals also pose very high ecological risks.

Element behavior during autoclave oxidation of polymetallic sulfide flotation concentrate containing tungsten and molybdenum

In this paper, we investigate the behavior of associated elements (tungsten, molybdenum, and bismuth) contained in a sulfide gold-bearing concentrate during its autoclave oxidation. The process is studied using a sulfide flotation concentrate, crushed to a particle sieve mesh size of minus 0.045 mm and containing 22.1 g/t of gold, 133.2 g/t of silver, 2.7% of tungsten, 13% of molybdenum, and 0.7% of bismuth. The process was carried out in a 2 dm3 autoclave at a temperature of 220ºC and an oxygen partial pressure of 0.7 MPa. The concentrations of sulfuric acid and iron ions in the solution were determined by titrimetric analysis. Inductively coupled plasma atomic emission spectroscopy was used to determine the concentrations of bismuth, tungsten, molybdenum, copper, silver, and arsenic in the solution, as well as the content of bismuth, tungsten, molybdenum, copper, arsenic, lead, and iron and sulfur forms in the cake. The cake was also examined using diffraction analysis. Experiments on cyanidation of oxidized cake were carried out in the pH range of 10.0–10.5 and a NaCN concentration of 1 g/dm3 with a PuroliteS992 ion exchange resin for 24 h. Autoclave oxidation experiments showed the sulfide oxidation degree to be higher than 99%. Extraction of molybdenum into solution in the form of [MoO2(SO4)n]-(2n-2) and MoO 2+ amounted to 95%. The decrease in the solid mass led to an increase in the concentration of bismuth and tungsten in the cake, with their contents reaching 1.66% and 12.7%, respectively. The main phases in the cake were established to be scheelite, anhydrite, plumboyarosite, and bedantite. The extraction of precious metals at the subsequent cyanidation stage amounted to 97.5% of gold and 91.6% of silver. Therefore, autoclave cyanide processing of sulfide gold-containing concentrates leads to a molybdenum extraction in the autoclave oxidation solution at the level of 95%. During cyanidation, more than 90% of gold and silver are extracted. Due to the significant amount of tungsten (17%), bismuth (0.9%), lead (5.3%), and molybdenum (3.3%), the obtained cake cannot be considered a waste product.

Mycosynthesis of TiO2 nanoparticles using Aspergillus penicillioides for toxic metal removal and photocatalytic applications

Globally, heavy metal pollution, especially lead and nickel, is becoming a problem and is of great concern due to its adverse effects. This study focuses on the eco-friendly biosynthesis of TiO2 nanoparticles using Aspergillus penicillioides metabolites as capping and reducing agents. The myco-synthesized TiO2 nanoparticles were characterized as oblate spherical and applied for photocatalytic removal of lead and nickel from industrial effluent. Optimal conditions for removal included lead and nickel concentrations of 60 μg/mL and 2 μg/mL, 10 μg/mL TiO2 nanoparticle concentration, a pH of 6, and sunlight irradiation. The kinetics and isotherm of adsorption were explained. Effective degradation of lead and nickel by using TiO2 nanoparticles was confirmed by atomic absorption spectroscopy. The nanoparticles demonstrated effective photocatalytic degradation of crystal violet dye achieved a high of 86.9% in 4h and 25% in 2 h, respectively, and showed promising biological activities, including antibacterial, antioxidant, and protein leakage properties. The hemolytic assay confirmed their ecological sustainability for bioremediation. The study highlights the effectiveness of new bio-based TiO2 nanoparticles arbitrated by Aspergillus penicillioides as effective bioremediation agents.

Effect of long-term application of pig slurry and NPK fertilizers on trace metal content in the soil.

One of the goals of sustainable agricultural production is to avoid soil contamination by elements defined as trace metals (TMs). The aim of this study was to assess the long-term impact of the use of pig slurry (PS) and NPK mineral fertilizers on the soil content of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn). In a 9-year crop rotation, PS was used three times only before root crops. The same four levels of NPK doses (N0P0K0, N1P1K1, N3P2K2, N4P2K2) were applied to both plots with and without PS. Soil samples were collected in early spring from topsoil (0-0.3m) and subsoil (0.3-0.6m). Three forms of TMs were determined in the soil: pseudo-total (Aqua regia); bioavailable (Mehlich 3 method) and readily bioavailable (mobile) forms (1M NH4NO3). The tested factors did not have a significant impact on the Cd, Cu and Pb content, regardless of the form analyzed and the soil depth. PS application significantly increased the content of bioavailable forms of Zn regardless of the year, and the content of pseudo-total Zn only in the sugar beet year, i.e. after manure application. Increasing NPK doses increased the content of mobile Zn in the topsoil, especially in PS plots. A tendency to accumulate mobile forms of Cd and Pb was also observed on NPK-fertilized plots. Thus, long-term application of high NPK doses may increase the risk of contamination of the food chain with these metals. The content of mobile Cd and Zn was positively related to the content of total nitrogen in the soil and negatively related to pH.

Ecology of Trifolium elazizense, an endemic alpine meadow species from Türkiye

This study presents some ecological characteristics of Trifolium elazizense, a local endemic alpine meadow plant species in the East Anatolian region of Türkiye. Elemental analyses were carried out in plants and soils. Soil-plant relationships were evaluated. The results obtained from all plant parts of Trifolium elazizense (root, stem and leaves) showed that the elemental concentrations of boron, calcium, copper, potassium, manganese, lead and zinc were within the limit values; cadmium, iron and magnesium were above the limit values. The general concentration of all elements in the soil samples is generally within acceptable limits.

Determination of some heavy metals in some vegetable samples grown around gwaigwaye dam

Consumption of vegetables contaminated with heavy metals poses a serious health risk such as cancer and kidney failure, this highlights the need for monitoring of these metals in vegetables. This study aimed at determining the concentrations of Cadmium, Nickel, Copper, Cobalt, Lead and Zinc in Cabbage, Lettuce and Moringa oleifera leaves grown around Gwaigwaye dams. These vegetables were collected, prepared, digested and analyzed using microwave plasma atomic emission spectroscopy. The results obtained were in the following ranges, 0.018±0.03 to 0.021±0.01 mg/kg for Cd, 0.00±0.00 to 0.19±0.01 mg/kg for Co, 0.00±0.00 to 0.086±0.00 mg/kg for Pb, 0.03±0.00 to0.9±0.00 mg/kg for Ni, 0.21±0.01 to 1.92±0.00 mg/kg for for Cu and 0.00±0.00 to 0.23±0.03 mg/kg for Zinc in cabbage, lettuce and moringa oleifera leaves obtained farmlands around gwaigwaye dam. Fortunately, the levels of these metals fell within the acceptable limits of FAO/WHO. The Analyzed vegetables are free from toxic metals and therefore suitable for human consumption. P- Values obtained from the statistical analysis were greater than 0.05, the differences in the concentrations of the metals observed were therefore not statistically significant.

Metal variability of the shrimp Palaemon elegans across coastal zones: anthropogenic and geological impacts.

This study focused on 120 specimens of the shrimp Palaemon elegans collected in intertidal zones in eight selected areas. This study aimed to assess the suitability of P. elegans as a bioindicator of natural and anthropogenic marine pollution. Metal concentrations of aluminum (Al), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), and zinc (Zn) were measured in shrimp collected from various sites in the Canary Islands, including areas affected by volcanic activity, industrial activity, and control zones. The determination of metal concentrations was conducted using inductively coupled plasma optical emission spectrophotometry (ICP-OES). The results showed significant differences in metal concentrations across the studied sites, with the highest levels of Al, Cu, Fe, Pb, and Zn observed in areas impacted by the Tajogaite volcanic eruption and harbor activity. Sites near old landfills and sewage pipes also exhibited elevated levels of Cd, Cu, and Pb, indicating strong anthropogenic influence. Al was found in the highest concentration in Harbour, reaching 25.7 ± 6.2mg/kg, while the lowest concentration was observed in Control Lp at 11.5 ± 0.69mg/kg. Conversely, lower metal concentrations were detected in control zones and areas with high dinoflagellate presence, suggesting a potential role of bioremediation by marine phytoplankton. The ability of P. elegans to accumulate metals in its tissues, particularly in areas of high pollution, highlights its potential as a bioindicator species. This study underscores the importance of P. elegans in monitoring marine pollution and provides insights into the environmental impact of both natural and human-induced contamination on coastal ecosystems.