Metal Concentrations In Sediments Research Articles

Mangrove forests provide critical ecosystem services, including carbon sequestration, shoreline protection, and serving as a food resource for coastal communities. However, these ecosystems face increasing environmental risks due to industrial and urban pollution, particularly contamination by heavy metals. This study assessed environmental quality in mangrove areas of Babitonga Bay, southern Brazil, using biomonitoring with the oyster Crassostrea rhizophorae and the mangrove tree Laguncularia racemosa. Sediment analyses revealed significantly elevated concentrations of copper, nickel, aluminum, and iron in Vila da Glória compared to Espinheiros, exceeding Brazilian environmental guidelines for copper and zinc. Biomonitoring results indicated high accumulation of arsenic and zinc in L. racemosa leaves, while oysters from Espinheiros exhibited higher concentrations of multiple heavy metals and smaller anatomical dimensions compared to those from Vila da Glória. Strong negative correlations were found between metal concentrations in oyster tissues and sediments, suggesting complex bioavailability dynamics. The study demonstrates the applicability of C. rhizophorae and L. racemosa as possible bioindicators of metal contamination in mangrove ecosystems. These findings underscore the importance of integrating biomonitoring approaches into coastal environmental health assessments to inform public health policies and conservation strategies aimed at promoting balanced ecosystem and human health.

Glacial-origin lakes in southern South America are increasingly exposed to anthropogenic pressures, but early signs of contamination often remain undetected in apparently pristine systems. In this study, we assessed the bioaccumulation of trace metals (Cu, Mn, Zn, Cr) in the tissues of the native freshwater mussel Diplodon chilensis and their relationship with sediment metal concentrations across 15 sites in six temperate lakes. Sediment quality was largely classified as unpolluted according to the geoaccumulation index (87% of values ≤ 0), yet high metal loads were found in mussel tissues, with Mn and Zn reaching 3325 mg·kg−1 and 350 mg·kg−1 respectively. Bioaccumulation factors were especially high for Mn (42.2) and Zn (32.1), reflecting efficient uptake from the environment. Multivariate analyses revealed spatial patterns driven by sediment composition and gradients of human influence, while regression models highlighted a significant role of fine sediment fractions in Mn bioaccumulation. These results demonstrate that D. chilensis can detect bioavailable metal fractions even in low-impact systems, underscoring its potential as a sentinel species. The integrative approach combining sediment chemistry, tissue analyses, and quantitative indices provides a replicable, cost-effective framework for the early detection of metal contamination in temperate lakes worldwide.

Mining liabilities as a source of toxic metals and physicochemical contaminants in tropical rivers.

This study provides a comprehensive assessment of polycyclic aromatic hydrocarbons (PAHs) and heavy metal concentrations in the surface sediments of the Pars Special Economic Energy Zone (PSEEZ), aiming to identify potential contamination sources and evaluate their ecological impacts. Sediment samples were collected from 14 stations during winter 2023 and analyzed for 16 priority PAHs and a suite of heavy metals. PAH concentrations ranged from below detection limits to 25.21 ng/g, with localized hotspots near industrial discharge zones. Heavy metals, including cadmium (Cd), lead (Pb), and arsenic (As), were detected at varying levels, with some exceeding sediment quality thresholds such as the Effects Range Low (ERL). Statistical source identification revealed petrogenic inputs from oil spills. The predominance of coarse-grained sediments in the PSEEZ, with minimal fine silt and clay content, suggests a lower overall retention capacity for PAHs and heavy metals. While fine particles were present only in limited areas, their potential for adsorbing contaminants remains a concern. Although most PAH and heavy metal concentration indicate below harmful thresholds, the detection of carcinogenic PAHs and elevated metal levels at specific stations indicates localized ecological risks, particularly for benthic organisms and potential trophic transfer within the marine food web.

Ecological risk assessment of hydrocarbons and metals in coastal sediments and bioindicator mussels in Buenos Aires, Argentina.

Estimating the bioaccessibility of trace elements in sediment to fish: a review of in vitro experimental approaches.

Environmental contaminants from mining activities are becoming problematic in the developing world, necessitating greater attention to their fate and transportation. In particular, gold mining activities that utilize strong lixiviants may result in heavy metal dissolution and distribution to environmental compartments. This study aimed to determine the status of some selected heavy metals in stream water, sediment and agricultural soil near a large-scale cyanidation gold mining operation, Laga Dambi. Ethiopia. The stream water, sediment and soil samples were digested under optimal digestion conditions. Inductively coupled plasma-optical emission spectrometer was used to determine the concentrations of Zn, Mn, Cu, Fe, Sn, Co, Ni, Cr, Pb, Cd, As, and Hg in samples collected from potentially contaminated sites associated with the Laga Dambi gold mine and control sites. The mine is notable because it is disposed of tailings in an impoundment created in a stream zone, where the stream flows over the tailings facility before exiting the mine site. The mean concentrations of the heavy metals in stream water and sediment were generally higher than the recommended levels reported by international agencies. The mean concentrations of Sn, Cr, Cd, and Hg were also high in agricultural soil that received irrigation water from the mine down gradient rivers. In general, stream water, sediment and agricultural soils were found to contain high concentrations of heavy metals, particularly Hg and As, which are typically associated with gold mining. The findings show that the heavy metal concentrations of stream water, stream bank sediment, and agricultural soil were high, indicating an increased risk for community exposure during consumption under the current conditions. On the basis of these findings, we strongly recommend strict monitoring and regulatory control of the study area to protect the environment and health of exposed populations.

The grain sizes and heavy metal contents of surface sediments in coastal ecosystems of Vietnam, including estuaries, seagrasses, coastal lagoons, embayments, and coral reefs, were analysed from 43 samples. Heavy metal pollution indices such as geoaccumulation (Igeo), the contamination factor (CF), the enrichment factor (EF), the ecological risk potential (ER), the degree of contamination (CD), and the ecological risk (RI) were used to evaluate sediment quality. The surface sediments were distributed into 9 types: very fine gravel, very coarse sand, coarse sand, medium sand, fine sand, very fine sand, very coarse silt, coarse silt, and medium silt. The average concentrations of Fe, Mn, Zn, Pb, Cu, Cr, V, As, Co, Cd, and Mo were 1,0015.45, 252.83, 67.91, 14.17, 12.27, 13.98, 17.28, 4.00, 5.63, 0.09, and 0.17 mg/kg, respectively, heavy. The Igeo was unpolluted. The CF had low contamination, except for Zn, which had moderate contamination. The EF were moderate (Pb and As) and moderate (Cd and Zn). The ER, CD, and RI indices were low. Although the average pollution indices were low, some areas in estuaries and coastal lagoon ecosystems presented high values. The negative correlation between Md and heavy metals revealed that grain size impacts heavy metal accumulation. The positive correlation between heavy metals revealed that they had a source origin. Factor analysis also revealed that natural sources of heavy metals accounted for 67.99% of the total heavy metals. In addition, heavy metals were also supplied from anthropogenic sources, with Cd and Zn accounting for 13.31% of the total heavy metals. Some areas in estuaries and coastal lagoon ecosystems where Cu, Pb, As, and Zn in sediment exceed the ISQG need to be monitored to monitor the impact and risk to coastal ecosystems.

Although effects of heavy metals in sediments on macrobenthic organisms have been extensively studied, few investigations have simultaneously assessed the influence of heavy metals in seawater and sediments on macrobenthic communities. This study investigated subtidal macrobenthic communities of Asan Bay, a coastal area in South Korea subject to extensive anthropogenic disturbances. It aimed to assess sources of heavy metals in seawater and sediments and evaluate their influence on the structure and composition of macrobenthic communities. Our findings suggest that cadmium (Cd), chromium (Cr), arsenic (As), and mercury (Hg) in seawater mainly originate from terrestrial inputs. Although the concentrations of heavy metals in seawater and sediments at most sampling stations complied with the Korean Environmental Quality Standards, the results of redundancy analysis (RDA), Spearman correlation, distance-based linear models (DistLM), and distance-based redundancy analysis (dbRDA) indicated that these heavy metals still influenced the structure of macrobenthic communities. Heavy metals in seawater were found to have a greater impact than metals in sediments, with Cr in seawater exerting the most decisive influence on macrobenthos (RDA showed that Cr explained 47.6% of the constrained species-environment relationship). Thus, Cr concentrations in bay seawaters should receive attention. Existing seawater quality standards may need to be reconsidered to reflect their effects on macrobenthic communities better.

This study aimed to investigate the seasonal variations in the concentrations of some heavy metals (cadmium, lead, copper, manganese, nickel, and zinc) in the surface sediments of Fatwa lagoon. Six different stations were selected as sampling points. Samples were taken over three seasons, and seasonal and annual average element concentrations were determined. It was observed that the seasonal concentrations of heavy metals (lead, copper, manganese, nickel, and zinc) during summer, autumn, and winter were within the normal range in the surface sediments and that the lagoon was not contaminated with these metals. However, cadmium concentrations in the surface lagoon sediments were found to exceed the permissible limits during the rainy season.

The 2015 Gold King Mine spill released 11.3 million liters of metal-laden water into the Animas River. To determine its impact downstream, we monitored Al, As, Cr, Fe, Mn, Pb, Zn, Ca, and Cu concentrations in irrigation ditch sediments fed by the Animas River during the 2017-2020 growing seasons. The elements, chosen for their presence in the original contaminant plume, were compared to regulatory risk assessment guidelines for soil. Sediments were collected from the mid-point and one side (at the high-water level mark) of fifteen irrigation ditch transects. Mixed models assessed for sampling time, sampling point (center or side), and their interaction for repeated measures in time and location in the ditch. Total concentrations collected from ditch sides were higher than the center concentrations for all elements except Mn. Only As exceeded the New Mexico Environment Department soil screening level of 7.07 mg kg⁻¹, increasing from 6.38 ± 0.47 mg kg⁻¹ (2017 pre-growing season) to 12.24 ± 2.67 mg kg⁻¹ (2019 post-growing season), a net increase of 5.86 ± 2.72 mg kg⁻¹. The Pb concentrations in ditch center sediments also increased over time, rising from 30.29 ± 6.90 mg kg⁻¹ to 49.87 ± 10.63 mg kg⁻¹, but remained below the U.S. EPA Residential Soil Screening Level of 400 mg kg⁻¹. In contrast, Mn and Zn fluctuated over the sampling period, while the other metal(loid) concentrations did not vary significantly. Monitoring sediment metal(loid) concentrations in irrigation ditches is essential not only for tracking the legacy impacts of upstream mining activities, but also for protecting downstream agricultural systems that depend on diverted river water, particularly in regions where irrigation infrastructure directly influences soil health, crop safety, and community resilience.

To evaluate the genotoxicity in the Loukkos River estuary, chemical and toxicological analyses were performed on water and sediments collected from six wadis. Heavy metal contents (Cr, Cu, Ni, Zn, Cd, Fe, and Pb), germination tests in lettuce, turnip, and alfalfa as well as micronucleus assay of Vicia faba were performed to assess phytotoxicity and genotoxicity. This study revealed that the Souani wadi had the highest concentration of Pb and Fe, and the highest concentrations of Zn, Cu, and Cd were recorded at the Aliane wadi. The heavy metal content in surface sediments is characterised by a high abundance of Fe followed by Zn and a low abundance of Cd in all river sediments studied. The germination index in water and sediment samples overreaches 80% in some cases. The highest mitotic index reaches 8.29% in the Souani wadi with a minimal value noted in the Oued el Maleh wadi (3.47%). The lowest micronucleus frequency is observed in the Martil wadi (1‰) and the highest value was noted in the Oued el Maleh (16.86‰), which reveals the genotoxic effect related to high levels of metals and salinity. These results support the use of micronucleus in V. faba as a tool in effectively monitoring genotoxicity in estuary.

This study investigates the impact of crude oil contamination on the physicochemical properties and heavy metal concentrations in surface water, sediment, and benthic organisms (Callinectesamnicola) at Bille Creek, Rivers State, Nigeria. Samples were collected bi-monthly from March 2023 to January 2024 from three stations in the creek. The study assessed the presence of Total Petroleum Hydrocarbons (TPH), Polycyclic Aromatic Hydrocarbons (PAH), heavy metals (Cobalt, Zinc, Nickel, Cadmium, Iron, Chromium), and physicochemical parameters including pH, turbidity, dissolved oxygen (DO), total dissolved solids (TDS), and chloride concentrations. The results revealed fluctuating TPH and PAH concentrations, with elevated levels in certain months, indicating crude oil spill events. Heavy metals such as Cobalt, Zinc, Nickel, and Cadmium showed significant variations across stations, with higher concentrations at Station 3, suggesting localized pollution. TPH and PAH levels in benthic organisms showed a similar trend, indicating bioaccumulation of contaminants. Elevated heavy metal concentrations in the benthic community pose risks to aquatic life and human health. The study highlights the need for continuous monitoring and remediation efforts to mitigate the long-term impacts of crude oil contamination in the ecosystem.

The remediation of Comprehensive Environmental Response, Compensation, and Liability Act or Superfund sites is limited to cleanup to levels no lower than background concentrations. However, both anthropogenically induced and naturally occurring metal concentrations in soil and sediments often complicate this cleanup process. To support informed decisions on heavy metal cleanup and the development of soil heavy metal-related policies in North Carolina, a statewide dataset of background heavy metal data from Superfund site investigations was compiled. The dataset represents background concentrations at 326 Superfund sites found in North Carolina, USA from 1985 to 2015. This 30-year dataset comprises site location data and analytical measurement results for 18 heavy metals in 624 soil and 228 sediment samples, obtained using standard methods. The data are presented in an interactive dashboard, offering summary statistics and graphical representations that can be customized to support specific decision-making needs. The data and Dashboard serve two main goals: 1) to inform and support cleanup decisions and policy development regarding soil heavy metals, and 2) to increase public awareness of the levels of naturally occurring and anthropogenic background heavy metals in soil and sediments across the state. The publicly accessible and interactive dashboard offers a deeper understanding of background environmental conditions in relation to evolving anthropogenic contamination within a broader context.

Environmental conditions in aquatic ecosystems could change due to the entry of additional materials, such as heavy metals and magnetic minerals. These materials, referred to as anthropogenic materials, could be derived from human activities. The presence of the materials could affect the magnetic properties and heavy metals content of river water and sediments. We have analyzed magnetic susceptibility and heavy metal concentration in sediments collected from Cisanti Lake. Cisanti Lake is known as “zero kilometers” of the Citarum River. Using the level of heavy metals in sediments, we calculated and evaluated pollution indices in the form of Contamination Factor (CF), Geoaccumulation Index (Igeo), and Pollution Load Index (PLI). The results showed that the magnetic susceptibility of sediments (𝜒𝐿𝐹) was in the range of 317.2 - 2274.9 (× 10-8) m3kg-1, inferring the dominance of ferrimagnetic minerals in sediments. Based on bivariate analysis of 𝜒𝐿𝐹 and the calculated frequency-dependent magnetic susceptibility or cFD (%), domain states of magnetic minerals are clustered at stable single domain (SSD)/multidomain (MD). Pollution indices of CF and Igeo showed that all sample points were contaminated by Cu at a considerable level. Moderate to significant contamination occurred in the studied area according to the PLI analysis. The positive strong correlation between 𝜒𝐿𝐹 and PLI suggests that magnetic susceptibility serves as a proxy indicator of contamination.

This study investigates the influence of pH and organic matter (OM) on the concentrations of potential toxic elements, that is, Fe, Mn, Cd, Cu, Cr, Ni, Pb, and Zn metals in the surface sediments of the Ganga River. The research explores the interaction between sediment properties and metal contamination in a 225-km stretch of the river in Uttar Pradesh, India, where industrial, agricultural, and domestic pollution contribute to heavy metal accumulation. Surface sediments act as reservoirs for these metals, influencing their mobility, bioavailability, and toxicity. Sediment samples from 10 sites were analyzed using Atomic Absorption Spectroscopy (AAS), revealing metal concentrations in the decreasing order: Fe > Mn > Cr > Zn > Ni > Pb > Cu > Cd. OM content ranged from 4.73% to 6.57% (mean: 5.79% ± 0.60%), whereas pH values (7.31-7.63) indicated slightly alkaline conditions. Correlation analysis identified significant relationships between metals and sediment properties. Strong positive correlations were observed for Mn-Pb and Fe-Cr, suggesting similar sources or geochemical behavior. Mn, Pb, Ni, and Cd correlated positively with OM, indicating its role in metal binding, whereas Fe, Cr, Zn, and Cu showed negative correlations. Furthermore, Mn, Zn, Pb, Ni, Cu, and Cd correlated positively with pH, suggesting reduced mobility in alkaline conditions, whereas Fe and Cr exhibited increased solubility. These findings underscore the importance of sediment characteristics in assessing heavy metal contamination and ecological risks. Understanding these interactions is vital for targeted pollution mitigation and sustainable river health management.

Heavy metal contamination and ecological risk assessment in drainage channel sediments from urban and agricultural areas.

Unveiling the prevalence of metal resistance genes and their associations with antibiotic resistance genes in heavy metal-contaminated rivers.

ABSTRACT Tanguar Haor is one of the best internationally significant freshwater wetlands in Bangladesh and was designated as a Ramsar Site in 2000. This study investigates metal contamination (Fe, Cu, Pb, Ni, Cr, and Cd) in surface sediment and ecological risks in Rowa Beel and Rupaboi Beel of Tanguar Haor through various pollution indices and Sediment Quality Guidelines (SQGs). The findings revealed that Fe and Pb concentrations exceeded shale values. The decreasing trend of the mean concentration of the studied heavy metals is Fe > Ni > Cu > Cr > Pb > Cd. The Enrichment factor (EF) and the Geo-accumulation Index (Igeo) values of Pb in Rowa Beel station indicate minor enrichment and uncontaminated to moderately contaminated by Pb. The decreasing trend for both average EF and Igeo of the heavy metals in the study area was Pb > Cu > Ni > Cr > Cd. According to SQGs, Cu, Pb, Ni, and Cr concentrations were within the Threshold Effect Level (TEL) values, suggesting no immediate effects on sediment-dwelling organisms, with a 21% probability of heavy metal toxicity to benthic biota. Multivariate statistical analysis found relation between Cu, Pb, Ni, and Cr which may indicate that they derive from similar origin. Overall, there is no significant contamination in Tanguar Haor from the tested heavy metals with a minor exception in case of Pb levels.

Essential metals such as Cu and Cr are needed in trace amounts, and their absence may cause serious problems, while non-essential metals such as Cd and Pb have no biological function, and their presence, even in very small quantities, may be toxic. This study aims to assess the level of some heavy metals in sediments of some intertidal creeks around Port Harcourt in the upper Bonny Estuary. The concentrations of heavy metals (Cr, Cd, Pb and Cu) in the sediments of five (5) intertidal creeks (Elelenwo, Choba, Eagle Island, Ogbunabali and Amadi-ama) around Port Harcourt metropolis, Nigeria, for a period of six (6) months, were investigated. Heavy metal concentrations were determined using Atomic Absorption Spectrophotometry. A General linear model of ANOVA was used to test for significant variations in space and time between study areas. The software packages – MS Excel and Minitab R16 were used. There were notable spatial and temporal variations of heavy metal concentrations in sediment across the study areas. Maximum concentrations (mg/kg) of Cr, Cd, Pb and Cu in sediments were 9.75, 3.56, 72.80 and 11.50, respectively. Heavy metal concentrations were discovered to exceed threshold effect values at several stations, with cadmium (0.44-3.56 mg/kg) and lead (72.80 mg/kg) being of particular concern. The study confirmed that areas like Ogbunabali and Choba were hotspots of contamination with regard to heavy metals due to solid waste disposal and discharges in those areas. The study, therefore, concluded that there was heavy metal pollution in the sediments of the intertidal areas studied.