Indicator Of Metal Contamination Research Articles

Spatial distribution of heavy metal contamination and risk indices of surface sediments in high-altitude lakes.

Lake ecosystems in northern Pakistan are the most critical resources that maintain and regulate water flow for downstream agricultural, domestic, industrial, and ecological processes. One consequence of these processes is that ecosystems deposit heavy metals (HMs), where lake stagnant conditions result in high vulnerability of water resources. For this purpose, the present study examined HMs such as cadmium (Cd), chromium (Cr), cobalt (Co), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) concentrations in high-altitude lakes (HAL) sediments of Mansehra district, northern Pakistan. Sediment samples were collected from the five HAL. This study used HM concentrations in lake sediments for the pollution factors such as contamination factor (Cf), pollution load index (PLI), sediment pollution index (SPI), ecological risk assessment (ERA), and risk index (RI). Among HMs, Fe showed the uppermost levels of 1410mg/kg in lake sediment, while Cd with lowermost levels of 1.05mg/kg. Results revealed that most HM concentrations in HAL sediments were within the threshold of sediments quality guidelines (SQGs), except for Cd. Among lakes, the sediments of Siri Lake showed higher contamination of HMs than others. Siri Lake sediments also showed higher Cf, PLI, ERA, and RI values than others. The majority of HMs in HAL sediments showed no contamination, except for Cd (considerable) and Pb (moderate) levels to the exposed aquatic ecosystem. This study revealed that 95% of sediment samples in HAL were noted low to medium-level risks to the exposed aquatic communities. Statistical and geospatial analyses revealed that geogenic sources of contamination are a significant contributor to HM contamination of HAL sediments compared to others.

Spatial analysis and soft computational modeling for hazard assessment of potential toxic elements in potable groundwater

Swiftly increasing population and industrial developments of urban areas has accelerated the worsening of the water quality in recent years. Groundwater samples from different locations of the Doon valley, Garhwal Himalaya were analyzed to measure concentrations of six potential toxic elements (PTEs) viz. chromium (Cr), nickel (Ni), arsenic (As), molybdenum (Mo), cadmium (Cd), and lead (Pb) using Inductively Coupled Plasma Mass Spectrometer (ICP-MS) with the aim to study the spatial distribution and associated hazards. In addition, machine learning algorithms have been used for prediction of water quality and identification of influencing PTEs. The results inferred that the mean values (in the units of µg L−1) of analyzed PTEs were observed in the order of Mo (1.066) > Ni (0.744) > Pb (0.337) > As (0.186) > Cr (0.180) > Cd (0.026). The levels and computed risks of PTEs were found below the safe limits. The radial basis function neural network (RBF-NN) algorithms showed high level of accuracy in the predictions of heavy metal pollution index (HPI), heavy metal evaluation index (HEI), non-carcinogenic (N-CR) and carcinogenic (CR) parameters with determination coefficient values ranged from 0.912 to 0.976. However, the modified heavy metal pollution index (m-HPI) and contamination index (CI) predictions showed comparatively lower coefficient values as 0.753 and 0.657, respectively. The multilayer perceptron neural network (MLP-NN) demonstrated fluctuation in precision with determination coefficient between 0.167 and 0.954 for the prediction of computed indices (HPI, HEI, CI, m-HPI). In contrast, the proficiency in forecasting of non-carcinogenic and carcinogenic hazards for both sub-groups showcased coefficient values ranged from 0.887 to 0.995. As compared to each other, the radial basis function (RBF) model indicated closer alignments between predicted and actual values for pollution indices, while multilayer perceptron (MLP) model portrayed greater precision in prediction of health risk indices.

Tire and road wear particles in infiltration pond sediments: Occurrence, spatial distribution, size fractionation and correlation with metals

Stormwater systems, such as infiltration ponds or basins, play a critical role in managing runoff water and reducing particulate pollution loads in downstream environments through decantation. Road runoff carries several pollutants, including trace metals and tire and road wear particles (TRWP). To improve our understanding of infiltration ponds as regards TRWP and their capacity to reduce TRWP loads, we have studied the occurrence, spatial distribution and size distribution of TRWP, as well as their relationship with metals, in considering the input of metals as tire additives, in the sediments of an infiltration pond located along the Nantes urban ring road (Western France), which happens to be a high-traffic roadway site. The sediment was analyzed using pyrolysis coupled with gas chromatography–mass spectrometry to determine the polymeric content of tires, specifically in quantifying the styrene-butadiene rubber (SBR) and butadiene rubber (BR) pyrolytic markers. By applying an SBR + BR-to-TRWP conversion factor, the results showed significant TRWP contamination, up to 65 mg/g, with a spatial enrichment from the entrance to the overflow section of the pond. Size fractionation revealed a bimodal distribution, indicating two distinct types of TRWP. The first type is characterized by small diameters (63–160 μm), suggesting the presence of TRWP less integrated with mineral and organic particles. The second type, characterized by larger diameters (200–500 μm), suggests a more pronounced integration with these same mineral and organic particles. A significant positive correlation between TRWP and metals (As, Cd, Cr, Cu, Li, Mo, Ni, Sb, V, Zn) was found (r > 0.739, p < 0.05). This correlation implies that TRWP and/or their associated phases may act as an indicator of metal contamination in the pond sediments. Lastly, a mass balance between TRWP inputs and the amount retained in the sediments underscores the role of infiltration ponds as “sinks” for TRWP.

Microbiodiversity Landscape Present in the Mine-Tailings of the “Sierra de Huautla” Biosphere Reserve, Mexico

Large-scale mining activities generate significant amounts of waste that accumulates in the environment. These wastes, known as mine tailings, contain high levels of heavy metals, posing risks to human health and causing severe damage to ecosystems. In this study, we determined the heavy metal content of mine tailings in the Sierra de Huautla Biosphere Reserve (REBIOSH), Mexico, and investigated their effect on microbial composition. One of the sites historically contaminated with metals was sampled in three different locations, labeled S1, S2, and S3. A fourth site free of heavy metals (S4) was also used as a control. Our results showed high levels of As, Pb, Cd, and Ag, potentially dangerous metals that exceed thresholds set by international regulatory agencies. Metal contamination indices indicated moderate to extreme enrichment for As, Cd, and Pb, posing potential ecological risks. A metagenomic study of mine tailings showed a core specie-specific microbiome covered by Sinimarinibacterium flocculans, Jiangella anatolica, Thiobacillus denitrificans, Fontimonas thermophile, Sphingomonas koreensis. These may be associated with the processing of heavy metals. A comparative study using the ALDEx2 revealed that less represented species like Variovorax paradoxus, Usitatibacter rugosus, Usitatibacter palustris, Sphingosinicella microcystinivorans, Sphingobium yanoikuyae, and Stella humosa may serve as microbial markers in metal-contaminated environments. In addition, we detected rare or low-abundance species belonging to the phylum Armatimonadota, Candidatus Melainobacteriota, Candidatus Saccharimonadota, Chlamydiota, Deinococcota, Elusimicrobiota, Bacillota, Rhodothermota and Verrucomicrobiota, which could play an important role in ecosystems contaminated with heavy metals. Also, we found site-specific taxonomic representatives such as Nitrososphaera gargensis and Nitrospira nitrificans dominating the S3 ecosystem; Ensifer aridi (S2 and S1), N. nitrificans (S2), while Reyranella soli dominate the S1 soil. These organisms could be crucial for nitrogen access in oligotrophic environments and underscore the adaptability of microbial life to extreme conditions. This is the first comprehensive study of the microbial composition in this important ecological site of the Mexican geography and can provide future guidance for the management and biological treatment of mining wastes.

Distribution of trace metals and metalloids in tissues of Eurasian Woodcock (Scolopax rusticola) from Southern Italy

Heavy metals and metalloids in the environment are recognised as a threat to the health of organism. Terrestrial birds are ideal subjects for the examination of these pollutants because of their high mobility and high intra- and interspecific variation in trophic levels. We examined the contents of 6 trace metals (Cd, Pb, Cr, Sb and V) and metalloids (As) in the liver, kidney, muscle, and feathers of woodcocks (Scolopax rusticola) from Southern Italy by a validated ICP-MS method. Significant differences in trace elements were found in all the tissues examined (p < 0.05). The highest Sb and Cr levels were found in feathers samples with mean values of 0.019 mg/Kg and 0.085 mg/Kg, respectively. High Pb levels were found in muscle, with 23 % of the samples exceeding the limits set by the European Union. Cd was predominantly found in the kidney samples (0.76 mg/Kg). Vanadium was the less abundant trace metal, showing the highest concentrations in the liver (0.028 ± 0.011 mg/Kg). Higher As levels were found in muscle (0.02 ± 0.015 mg/Kg). No significant differences between sex and age classes (juveniles vs. adults) were found, nor were there correlations between morphometric parameters and trace metal/metalloid contents. Principal Component Analysis determined differences in metal accumulation between tissues. Feathers were confirmed as useful indicators of metal contamination. The results of this work confirmed that the accumulation of toxic elements in the tissues of woodcocks is primarily influenced by ecological traits such as feeding habits and migration status. Statistical analysis of the tissues would seem to exclude important accumulation phenomena of Pb. The high levels found in the muscle could be due to lead ammunition. This work provides the first data on the accumulation of As, Cr, Sb, and V in woodcocks tissue, providing a more comprehensive insight into the potential impact of these pollutants on birds.

Spatial distribution, bioaccessibility, and human health implications of potentially toxic elements in mining-impacted topsoils in Obuasi Municipality of Ghana.

Potential toxic elements emanating from extracted ores during gold processing present occupational and unintentional health hazards in communities, the general populace, and the environment. This study investigated the concentrations and potential health effects of metal content in the topsoils of Obuasi municipality, which has been mined for gold over the past century. Surface topsoil samples, sieved to 250µm, were initially scanned for metals using x-ray fluorescence techniques, followed by confirmation via ICP-MS. In vitro bioaccessibility assays were conducted using standard methods. The geoaccumulation indices (Igeo) indicate high enrichment of As (Igeo = 6.28) and Cd (Igeo = 3.80) in the soils, especially in the eastern part of the municipality where illegal artisanal mining is prevalent. Additionally, the southern corridor, situated near a gold mine, exhibited significant levels of As and Mn. Results obtained for the total metal concentrations and contamination indices confirmed the elevation of the studied potential toxic elements in the Obuasi community. A hazard index value of 4.42 and 3.30 among children and adults, respectively, indicates that indigens, especially children, are susceptible to non-cancer health effects.

Heavy metal distribution and ecological pollution assessments in water bodies and sediments in rural areas of Bangladesh

Pollution in rural waterbodies, sediments, and aquatic species due to long-range transportation and mobilization of heavy and toxic metals contaminants is a growing concern in many developing countries nowadays. Environmental components in rural areas are usually considered as safe and information on metals toxicities in rural natural resources are very limited. Herein, accumulation, mobilization, and distribution of eight different elements (Fe, Ni, Mn, Pb, Cr, Cu, Cd, As) in water bodies and sediments in rural areas of Bangladesh have been investigated successfully. Different metals contents found in water and sediment were compared with standard threshold levels reported by WHO, USEPA, China, and the results revealed the occurrence of pollution in respective environmental resources with the excessive presence of some heavy metals. Pollution characteristics analyses with trace metal pollution index (TPI), heavy metal evaluation index (HEI), contamination index (Cd), and comprehensive pollution index (CPI) indicated that water bodies in rural areas are contaminated with Pb, Mn, Fe, and different metals contents were varied in the order of Fe > Mn > Cu > Pb > Cr > As > Cd > Ni (mg/L). Contamination analyses in sediments with potential ecological risk index (PERI), pollution load index (PLI), metal enrichment (EF), and geo-accumulation index (Igeo) assessments revealed the occurrence of pollution in sediments with Ni, Cr, Cu, and the translocations of different heavy metals in rural sediments were varied in the order Fe > Mn > Cr > Ni > Cu > Cr > Cu > Pb > As > Cd (mg/Kg). PLI data of metals showed higher than one and the magnitudes of Igeo were greater than zero which indicated inordinate accumulation of Ni, Cr, and Cu in sediments. The present research findings offer significant information on how the pollutants from point sources impact the environmental ecosystems in rural areas of Bangladesh due to the long-range pollution with flood and other natural disasters that occur frequently in the region. These results may be useful for making necessary environmental policies in developing countries regarding long-range pollution.

GIS-based assessment of groundwater vulnerability to heavy metal contamination via water quality pollution indices in urban Aligarh, India

Abstract The study presents an assessment of groundwater vulnerability due to heavy-metal contamination using Heavy Metal Pollution and Contamination Index of Urban Aligarh. Globally, hazardous compounds in industrially contaminated sites are pressing and high-priority issue. A detailed risk assessment was carried out to determine the potential health hazards linked to locations that were recently polluted. A total of 17 groundwater samples were taken from hand-pump and 20 industrial drainage samples were collected from selected areas of Aligarh. The concentration of heavy-metals in the collected samples analyzed were shown on maps using ArcGIS software and interpreted for Heavy Metal Pollution Index (HPIx) and Contamination Index (CDx). These analyzed values were subsequently compared with the permissible limits established by the agencies like EPA, WHO, and BIS. The mean concentration of heavy-metals in groundwater of different locations was observed as follows particular sequence: Ni (1.40), Cu (0.58), Zn (0.06), Fe (0.08), Mn (0.04), Cr (0.001), Pb (0.00025) mg/l. Additionally in industrial effluent, Cr (18.3), Ni (13.34), Mn (1.16), Cu (1.99), Pb (1.2), Fe (6.3), Zn (0.51) mg/l. According to HPIx, the analysis reveals 64.7%, of visited areas belonged to have safe groundwater. Conversely, a smaller proportion, 35.3%, was found falling into heavy metal-polluted group.

Determination of heavy metal contamination and pollution indices of atmospheric dust in Dushanbe and Ayvaj, Tajikistan

In this paper was studied the content of heavy metals in atmospheric dust of Dushanbe and Ayvaj. Dust samples were taken and analyzed to determine the content of heavy metals (HM): Zn, Pb, Cu, Cr, V, Ni, Co, As, Sr, MnO, TiO2 and Fe2O3 using X-ray fluorescence spectrometry. The pollution levels and environmental risks of HMs were assessed using the geoaccumulation index, contamination factor, pollution load index and potential ecological risk index. The results revealed severe contamination of atmospheric dust from Ayvaj and Dushanbe with particularly hazardous HMs such as As and Pb, the proportion of As is higher in the dust of Dushanbe, and the contribution of Pb is significant in the samples of Ayvaj. The concentrations of As, Pb, Zn, MnO, Sr, TiO2, V, Co in the dust of Dushanbe and As, Pb, Zn, Sr, TiO2, Cu in the dust of Ayvaj showed high variability (CV&gt; 35%), which indicates an intense influence of anthropogenic activity. The results of the pollution factor analysis show that As, Co, V in Ayvaj atmospheric dust samples and Pb, Cr, Ni, V, MnO in Dushanbe samples were assigned to the class of very high pollution (CF&gt;3). According to the results of the geoaccumulation index Ayvaj is heavily polluted with the following elements: V, Pb, Cr (3&lt; Igeo ≤4). Based on the ecological risk index method, As and Pb were found to be priority pollutants in the study areas.

Assessment of Heavy Metal Contamination and Pollution Indices in Avicennia marina of Nabq Mangrove Forest, the Red Sea, Egypt

Assessment of Heavy Metal Contamination and Pollution Indices in Avicennia marina of Nabq Mangrove Forest, the Red Sea, Egypt

Urbanization-driven soil degradation; ecological risks and human health implications.

Urban soils contaminated with heavy metals and pesticide residues are of great concern because of their adverse impact on human health. A total of 66 agricultural topsoil samples (15cm) were collected to represent the study area and determine how anthropogenic activities adversely affect soil quality and human health. Sampling was conducted in the summer, when it was dry and hot, and in the winter, after atmospheric deposition. Seventeen potentially hazardous metals/metalloids (Ag, As, Al, B, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Mo, Pb, Se, Zn, and V) were measured in the soils. The mean concentrations of metals ranged between 0.05 and 8080mg/kg, and their distribution was site-specific, with high pollution at the sampling sites owing to proximity to human activities. In agricultural areas, the greatest arsenic concentration was recorded at 48mg/kg. The potential ecological risk index (PERI) and health hazard index (HI) were calculated, as well as metal contamination indices including contamination factor (Cf), geo-accumulation index (Igeo), and pollution load index (PLI). The mean PLI was calculated to be 4.89, indicating that the area is highly polluted. The potential ecological risk index showed remarkably high risks for As, Cd, and Hg, and moderate risks for Ni and Pb. The arsenic hazard index (HI) was greater than one (2.41) in children, indicating a risk of exposure through ingestion. Pesticide residue analyses were performed in areas where the metal intensity was high. Banned or restricted organochlorine pesticide (OCPs) residues, including, dieldrin, endrin ketone, endosulfan I, II, heptachlor, heptachlor epoxide, lindane (γ-HCH), PP-DDD, and methoxychlor, were detected between 0.002 and 1.45mg/kg in the soil samples.

Characterization of sargassum accumulated on Dominican beaches in 2021: Analysis of heavy, alkaline and alkaline-earth metals, proteins and fats

This paper presents the characterization of sargassum that reached the shores of eight Dominican beaches in 2021. The analysis of heavy, alkaline and alkaline-earth metals was performed by ICP-OES. Twelve heavy metals were studied, with the highest concentrations corresponding to Fe, As, and Zn. Regarding the alkaline and alkaline-earth metals, the highest concentrations were detected for Ca, K, Na and Mg. The high values of arsenic and alkali and alkaline-earth metal salts do not suggest using these algae in agriculture. It is recommended to carry out arsenic speciation studies to assess whether the form in which it is found is bioavailable for plants and animals. The heavy metal contamination index was determined, which ranged between 0.318 and 3.279. Finally, for the first time in the country, the organic fraction of sargassum was analyzed.

Appraisal of trace metals pollution, sources and associated health risks using the geochemical and multivariate statistical approach

Trace metals pollution in the freshwater system is an emerging concern. Thus, a systematic study was performed in the Wadi Fatimah basin to appraise the trace metals pollution status, sources and associated health risks using integrated tools, namely indices, international standards, multivariate statistical techniques and health risk assessment models. The groundwater salinity shows a wide range (TDS = 391 to 11,240 mg/l). The heavy metal pollution index and contamination index justify that most of the samples are unfit for drinking due to high metal pollution. Severe pollution is noticed by the Li (100%), Ni (98%), Pb (86%) and B (78%), and it is in the decreasing order of Mo > Cr > Al > Fe = Mn > V > Sr > Ag > Cu. Pearson correlation matrix suggests that most of the metals have a significant strong positive correlation with Al, Fe and Mn and originated from geogenic sources. Principal components analysis and R-mode HCA indicate that trace metals are mostly derived from weathering of aluminium silicates, oxides/hydroxides of Fe and Mn followed by evaporation, evaporite dissolution and restricted flow. Q-mode HCA resulted in 4 clusters, and the water chemistry of WG1 and WG4 is governed by mineral weathering. In addition, evaporation also enriched the metal load and salinity in WG4 wells. In WG2, the water chemistry is predominantly affected by long storage, evaporation and mineral weathering. In WG3, the water chemistry is influenced by evaporation, irrigation return flow and evaporite dissolution. The hazard quotient and hazard index suggest that groundwater in this basin causes potential non-carcinogenic health risks to the consumer. This study strongly recommends treatment for groundwater before supply to the local inhabitants.

Metrologically sound comparison of trace-metal levels in sea cucumber tissues from different species and habitats

Sea cucumbers are indicators of metal contamination in sea bottoms due to their low mobility and feeding behaviour. Comparing contaminations of specimens from different locations, habitats, and/or organs allows understanding of contamination processes and differences. However, the interpretation of these data is affected by the variability of contamination levels in specimens, the uncertainty of tissue analyses, and the complex correlation of mass fractions estimated by using the same calibration of the used instrumental method of analysis. This work presents a novel tool for the sound comparison of contamination levels of biota where all mentioned factors are considered to produce reliable and undisputable information on the studied system. The Monte Carlo simulation of uncertainty components, affecting the determination of mean contamination levels observed in selected types of tissues, allowed simulating mean contamination differences and determining if these are meaningful. This tool was used to assess the levels of Cd, Cu, Ni and Pb of animals collected in different locations of Sesimbra-Portugal. It was concluded that specimens that selectively consume macroalgae have larger contamination levels than animals feeding on sediment. The gut is the most contaminated organ suggesting intake from feeding is dominant. Three of the analysed animals have Pb mass fractions larger than a maximum admissible value for human consumption of 3 mg kg−1 with a probability larger than 2.5%.

Assessment of As, Cr, Cd, and Pb in urban surface water from a subtropical river: contamination, sources, and human health risk

ABSTRACT This work aimed to determine the level of some toxic elements (As, Cr, Cd, and Pb) in the water of the Rupsha River, Bangladesh, concerning their potential dangers to human exposure. The elemental concentrations (mg/L) were determined using Atomic Absorption Spectrometer and found to decrease in the order of Cr (0.041) > Pb (0.029) > As (0.004) > Cd (0.002). The level of elements in this river water surpasses various international limits, making it unfit for human consumption. Furthermore, the metal pollution index and contamination index indicated that the water was also unsuitable for this purpose. The elements chosen were persuasive to discern the hazard quotient of non-carcinogenic risk. Moreover, total targeted hazard quotient (TTHQ) values were found for adults and children within acceptable limits (TTHQ <1). The value of carcinogenic risk did not surpass the range (10−6 to 10−4) of the threshold limit. Due to their high-water consumption per unit of body-weight and physiological development, children were found to be more sensitive than adults. Multivariate analyses demonstrated that human activities were the primary origin of toxic elements in river water. According to the findings, urban and industrial effluents should be treated before being released into rivers. Development along the river bank must be carefully controlled to safeguard the river environment. In the end, this will improve the quality of the water and lower the chance that people will be exposed to metals.

Heavy Metal Contamination Index, Metal Index and Polycyclic Aromatic Hydrocarbon Content of Ochani River in Ogoni, Rivers State, Nigeria

The Heavy metal Pollution Index (HPI), Metal Index (MI) and the Polycyclic Aromatic Hydrocarbon (PAH) contents of crude oil-polluted Ochani River in Ejamah-Ebubu community were investigated using physicochemical properties, Heavy Metal Analytic Method (AAS), GC-MS method and heavy metal pollution model. The results showed that Ochani River sampling station 2 (ORPS 2) had highest values of temperature, conductivity, turbidity, total solid (TS), total dissolved solid (TDS), Total Suspended Solid (TSS), Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and nitrates with values as (32oC, 260 µScm-1, 42NTU, 460 mg/L, 526 mg/L, 400 mg/L, 15 mg/L, 10 mg/L, 25 mg/L and 7.5 mg/L respectively) compared to Ochani River sampling station 1 (ORPS 1) with values as (30oC, 200 µScm-1, 38NTU, 400 mg/L, 500 mg/L, 380 mg/L, 13 mg/L, 9.0 mg/L, 22 mg/L and 6.8mg/L respectively). However, these values of ORPS 1and 2 were higher than the unpolluted water sample (UWS) and WHO standard limits. Heavy metals obtained in Ochani River were rankedas Fe &gt; Cu &gt;Pb&gt; Zn &gt; Cr &gt; Cd &gt;As. The values obtained from crude oil polluted water samples were highest when compared with the values obtained of the UWS and WHO standard limit. The heavy metal pollution index of Ochani River was calculated as 402.32 mg/L which was higher compared with the critical pollution index value of 100. The metal index obtained was 49.88mg/L showing that the water quality classified to be seriously polluted. The Polycyclic Aromatic Hydrocarbon (PAH) components present in Ochani River include fluorene, naphthalene, dibenzyl(a,h)anthracene, benzo(k)fluoranthene and benzo(a)pyrene. However, these values of PAH components obtained were highest in ORPS 2 compared to ORPS 1. No PAH content was detected in UWS. However, the values of PAH obtained in both ORPS 1 and 2 were higher compared with WHO standard limit. In conclusion, Ochani River which is an important river used for irrigation and domestic activities by the populace in that community, is highly polluted with heavy metals and carcinogenic PAHs. We therefore recommend that Ochani River is unsafe for drinking, domestic and agricultural activities of the community where it is sited.

Cadmium (Cd) and Copper (Cu) Exposure and Bioaccumulation Arrays in Farm Ruminants: Impact of Forage Ecotypes, Ecological Sites and Body Organs

Copper (Cu) and cadmium (Cd) metal distribution in soil–plant ecosystems and their public health risk impact on ruminants (cows, buffalo, and sheep) are explored in the present investigation. Five different forage crops were selected, and the foraging responses of three types of ruminants (cows, buffalo, and sheep) at three ecological sites were evaluated. The soil of these three ecological sites was metal polluted (due to wastewater irrigation) and was studied to evaluate the metal contamination and pollution load index. For the assessment of Cd and Cu, soil, vegetation, blood, hair, and feces samples were collected and analysed using an atomic absorption spectrophotometer. High consumption of fodder crops (Sorghum bicolor Kuntze, Sesbania bispinosa (Jacq.) W. Wight, Cynodon dactylon (L.) Pers., Suaeda fruticosa (L.) Forssk., and Tribulus terrestris L.) by cows and buffalo at site-III resulted in an increase in daily Cu and Cd intake. The pollution load index was higher at site-II and site-III, indicating a severe health risk scenario for local inhabitants. Cd and Cu were at their maximum levels in fodder crops. A significant increase in the concentrations of Cd and Cu was found in the blood, hair, and feces of cows and buffalo at site-III. Ecological indicators such as the bioaccumulation factor, the pollution load index, and the enrichment factor were found to be higher in buffalo than cows. The Cd level in forages was highest at the site-III Cd level and in the order of S. bispinosa &gt; S. fruticosa &gt; T. terresteris &gt; C. dactylon &gt; S. bicolor. Although these levels were lower than the permissible maximum limit, they were generally higher in the forage crops. Exposure of local inhabitants to the consumption of milk and meat from these cattle showed the serious health risks consequences. This situation can be properly managed by general monitoring of soil and vegetation pollution, avoiding metal contamination in the soil and food chain components, and using treated waste water and other alternate water sources for forage irrigation.

Heavy Metal Content of Water in Ikwu River (Umuahia, Nigeria): Pollution Indices and Health Risk Assessment Approach

The heavy metal content of a local drinking water source in Southeast Nigeria was studied between January 2021 and June 2021 in 3 stations. Pollution indices (heavy metal pollution index and contamination index) and health risk assessment for non-carcinogenic were used to check the water’s suitability for human consumption. Eight heavy metals were assessed with standard methods and compared with The Nigerian Drinking Water Quality Standard. Some metals (Mn, Pb, Fe, Cd, and Cr) exceeded acceptable limits. The heavy metal pollution index exceeded the threshold value (100), ranging between 503.56 and 746.80. The contamination index ranged between 10.74 and 17.12 indicating high contamination potential and all the hazard indices exceeded unity (1). The heavy metal content, pollution indices, and health risk assessment has shown that the water from the Ikwu River was not fit for human consumption. The main metals that influenced the results were Mn, Pb, Fe, Cd, and Cr, because they exceeded limits while Cd and Cr were responsible for the observed adverse health risk. The children were more vulnerable. The geogenic influence was a major factor exacerbated by season and anthropogenic activities in the river.

Silica geothermometry and multi indices approach to characterize groundwater from Midyan region in Northwestern Saudi Arabia

This research was performed in the northwestern part of Saudi Arabia, where physico-chemical parameters obtained from 81 groundwater samples were interpreted. High heat flow granites underlie the study area, and their weathering and erosion cause the accumulation of radioactive elements in sediments surrounding these granites, resulting in a high temperature of the circulating water. The chalcedony (no steam loss) temperature of the circulating groundwater was determined using the dissolved silica values in the samples. Based on the obtained chalcedony temperature, the samples were categorized into two groups. The first group contained 63 samples with chalcedony temperatures less than 50 °C, and the second group contained 18 samples with temperatures above 50 °C. The Cl–SO4–HCO3 ternary diagram showed that the samples with higher temperatures were chloride type and plotted close to the mature water. The silica concentration showed a strong correlation with chloride, indicating that Cl was mostly obtained from mineral dissolution, although the wide variation in Cl and TDS for a narrow range of silica values indicated groundwater mixing or anthropogenic influence. According to the Piper plot, the (Ca + Mg)-(SO4+Cl), (Ca + Mg)-(HCO3+CO3), and (Na + K)–(SO4–Cl) types are the three key groundwater facies in the area. The TDS levels in water with chalcedony temperatures above 50 °C were high (over 5000 mg/L), with chloride dominating the composition. Pollution indices of the samples in terms of heavy metals and major ions were also calculated to determine the suitability of the groundwater for human consumption. The heavy metal pollution index, heavy metal evaluation index, and heavy metal contamination index indicated no HM pollution. However, the water quality index, which uses major ions to determine drinking water quality, showed that approximately 50% of the examined samples were unfit for consumption without any primary treatment.

Variability in mentum deformities of Tanytarsus larvae (Diptera, Chironomidae) in a metal rich basin in Northern Mexico

Mentum deformities in chironomids have been commonly used as indicators of metal contamination in freshwater ecosystems. Incidence of these deformities suggests sublethal effects and can provide early signals of environmental deterioration. While anthropogenic metal pollution is known to lead to an increase in deformities in chironomids, natural background deformity incidence information is key to their effective use as biomonitoring tools. Here we explore the incidence of deformities from 5000 Tanytarsus (Diptera, Chironomidae) menta in relation to water physicochemical, and sediment metal (Al, As, Cu, Fe, Mn, Pb, Zn) concentration data from numerous sites in the naturally metal-rich Sonora River (NW Mexico) obtained over a two-year period. Higher metal concentrations were found in the upper basin. Higher salinity, total suspended solids and conductivity were found in the lower basin. Only As and Cu were occasionally found above published threshold effect levels (TEL). The proportion of deformities (% D) was low (2.1%) and a generalized linear model only explained 25.36% of % D variability among samples; this model included several physicochemical parameters. The only metal significantly related to deformities was Cu. Despite significant spatial and temporal variability in all metal concentrations and other physicochemical parameters in the basin, we were unable to explain a strong relationship between metal concentration and deformity incidence. Our results, based on consistent % D quantification from 5000 samples from a single taxon, suggest that natural variation in metal concentrations, even when statistically significant, is not associated with notable variations in the incidence of deformities.