Heavy metals in lake surface sediments in protected areas in Poland: concentration, pollution, ecological risk, sources and spatial distribution

Organic matter is a predominant control on total mercury concentration of near-surface lake sediments across a boreal to low Arctic tundra transect in northern Canada

Mercury (Hg) is a bioavailable and toxic element with concentrations that are persistently high or rising in some Arctic and subarctic lakes despite reduced atmospheric emissions in North America. This is due to rising Hg emissions to the atmosphere outside of North America, enhanced sequestration of Hg to sediments by climate-mediated increases in primary production, and ongoing release of Hg from terrestrial reservoirs. To evaluate the influence of organic matter and other parameters on Hg accumulation in northern lakes, near-surface sediments were sampled from 60 lakes across a boreal to shrub tundra gradient in the central Northwest Territories, Canada. The organic matter of the lake sediments, assessed using programmed pyrolysis and petrology, is composed of a mixture of terrestrial, aquatic, and inert organic matter. The proportion of algal-derived organic matter is higher in sediments of lakes below treeline relative to shrub tundra sites. Total sedimentary Hg concentration is correlated to all organic matter constituents but is unrelated to latitude or lake position below or above treeline. The concentrations of Ag, Ca, P, S, U, Ti, Y, Cd, and Zn are also strong predictors of total sedimentary Hg concentration, indicating input from a common geogenic source and/or common sequestration pathways associated with organic matter. Catchment area is a strong negative predictor of total sedimentary Hg concentration, particularly in lakes above treeline, possibly due to retention capacity of Hg and other elements in local sinks. This research highlights the complexity of controls on Hg sequestration in sediment and shows that while organic matter is a strong predictor of total sedimentary Hg concentration on a landscape scale and across extreme gradients in climate and associated vegetation and permafrost, other factors such as catchment area and sources from mineralized bedrock are also important.

Appraisal of metallic accumulation in the surface sediment of a fish breeding dam in Türkiye: A stochastical approach to ecotoxicological risk assessment

This study examines the levels and patterns of potentially toxic elements (PTEs) in surface sediment of Almus Dam Lake (ADL), a key fish breeding site in Türkiye. PTE concentrations in sediment were ranked: Hg (0.05 ± 0.01) < Cd (0.16 ± 0.01) < Pb (9.34 ± 1.42) < As (18.75 ± 15.65) < Cu (63.30 ± 15.17) < Ni (72.64 ± 20.54) < Zn (86.66 ± 11.95) < Cr (108.35 ± 36.40) < Mn (1008 ± 151) < Fe (53,998 ± 6468), with no significant seasonal or spatial differences. Ecological risk indices (mHQ, EF, Igeo, CF, PLI, Eri, mCd, NPI, PERI, MPI, and TRI) showed low contamination levels. Health risk assessments, including LCR, HQ, and THI, indicated minimal risks to humans from sediment PTEs. Statistical analyses (PCA, HCA, SCC) identified natural, transportation, and anthropogenic PTE sources, with slight impacts from agriculture and fish farming. This research underlines contamination status of ADL and emphasizes the need for targeted management strategies, offering critical insights for environmental safeguarding.

Spatiotemporal ecological risk evaluation and source identification of heavy metals and nutrients in the water and lake surface sediment in a protected catchment area of a volcanic lake

Indonesia has numerous lakes; however, research on the spatiotemporal sediment quality and source identification in lakes remains limited. The overaccumulation of heavy metals and nutrients in lakes severely threatens aquatic ecosystems. This study aims to identify potential sources of metallic deposits (Cu, Pb, Cr, Fe, Al, and Cd) and nutrients (TN and TP) in lake-surface sediment, utilizing enrichment factors (EF), geoaccumulation indices (Igeo), potential ecological risk indices (Er), and risk indices (RI). Multivariate statistical analyses, including principal component analysis (PCA) and Pearson's correlation analysis, were conducted to pinpoint pollution sources linked to land use. Eight sampling sites for surface sediment and water were examined in both wet and dry seasons at Menjer Lake, chosen for its diverse applications in tourism, hydropower, floating net cages, and extensive agriculture in its catchment. Correlation and PCA results indicated that Pb, Fe, and Al mainly originate from tourism, while Al, Fe, TN, and TP are associated with agriculture. The highest average loading from land use was observed in agriculture (> 0.8), floating net cages (> 0.76), and tourism (> 0.68). Furthermore, the highest loading from nutrients and all metals were TP (> 0.71) and all metals (> 0.35), respectively. Ecological risk assessment revealed low to moderately polluted EFs and Igeo in the dry season. However, Menjer Lake's Er and RI for heavy metals were generally classified as unpolluted.

Impacts of the steel industry on sediment pollution by heavy metals in urban water system

The impact of the steel industry on sediment heavy metal (HM) pollution in urban aquatic environments was investigated in a major iron ore-producing area (Ma'anshan) in China. The concentrations of Cd, Cr, Cu, Ni, Pb, and Zn were 9.68 ± 3.56, 170.31 ± 82.40, 90.62 ± 19.54, 30.61 ± 6.72, 125.43 ± 63.60, and 1276.59 ± 701.90 mg/kg in the steel industry intruded upon sediments and 4.63 ± 1.41, 87.60 ± 10.96, 52.67 ± 19.99, 37.49 ± 6.17, 35.84 ± 11.41, and 189.02 ± 95.57 mg/kg in the control area, respectively. Comparing with the local soil background (0.08 mg/kg for Cd, 62.6 mg/kg for Cr, 19.3 mg/kg for Cu, 28.1 mg/kg for Ni, 26.0 mg/kg for Pb, and 58.0 mg/kg for Zn), significantly higher levels of Cd, Cr, Cu, Pb, and Zn were detected in the steel industry affected sediments. The enrichment factor and principal component analysis indicated that the heavy metals (HMs), except for Ni, were primarily derived from anthropogenic inputs, particularly from steel industrial activities. Multiple risk assessment models suggested that the sediments affected by industrial activities showed significant toxic effects for Cd, Cr, Pb, and Zn, with Cd being the main contributor to sediment toxicity. However, the alkaline nature of the sediments (pH = 7.85 ± 0.57) and the high proportion of residual fraction Cd (61.09% ± 26.64%) may help to reduce the toxic risks in the sediments. Effective measures to eliminate tinuous thethe continous input of Cd and Zn via surface runoff are crucial.

Pollution patterns and their effects on biota within lotic and lentic freshwater ecosystems: How well contamination and response indicators correspond?

Aquatic environments are often severely polluted with chemical substances of anthropogenic origin, which can pose a potential threat to aquatic organisms and human health. In this study, patterns and sources of heavy metals (HMs, 6 metals) and polycyclic aromatic hydrocarbons (PAHs, 16 hydrocarbons), contamination indicators, environmental genotoxicity measures and metrics of ecological status in lotic and lentic ecosystems were collated for the first time. Chemical analysis has confirmed previously reported long-term contamination at certain study sites. The sediments of Lake Talkša, located in a city and characterized by exclusive anthropogenic pressure, exhibited the highest levels of contamination by both HMs and PAHs. Through positive matrix factorization (PMF) analysis, vehicle and industrial emissions were identified as the primary sources of HMs and PAHs. Our results revealed that frequencies of genotoxic aberrations were higher in river sites compared to lakes, with the highest genotoxic risk observed in the Nemunas River below industrial cities Alytus and Kaunas. Surprisingly, even the severely contaminated Lake Talkša showed only a "moderate" grade of genotoxic risk, highlighting the potential for adaptation of biota to long-term contamination especially in lentic ecosystems. The ecological quality status assessed by macroinvertebrate metrics, which may be sensitive to observed high biological contamination, appeared to be unrelated to contamination patterns. Consequently, to obtain the robust information on anthropogenic contamination and its effects, a combination of various assessment methods and metrics should be employed.

Investigation and comparative analysis of ecological risk for heavy metals in sediment and surface water in east coast estuaries of India

The sediments and surface water from 8 stations each from Dhamara and Paradeep estuarine areas were sampled for investigation of heavy metals, Cd, Cu, Pb, Mn, Ni, Zn, Fe, and Cr contamination. The objective of the sediment and surface water characterization is to find the existing spatial and temporal intercorrelation. The sediment accumulation index (I_sed), enrichment index (I_En), ecological risk index (I_EcR) and probability heavy metals (p-HMI) reveal the contamination status with Mn, Ni, Zn, Cr, and Cu showing permissible (0 ≤ I_sed ≤ 1, I_En ˂ 2, I_EcR ≤ 150) to moderate (1 ≤ I_sed ≤ 2, 40 ≤ R_f ≤ 80) contamination. The p-HMI reflects the range from excellent (p-HMI = 14.89-14.54) to fair (p-HMI = 22.31-26.56) in off shore stations of the estuary. The spatial patterns of the heavy metals load index (I_HMc) along the coast lines indicate that the pollution hotspots are progressively divulged to trace metals pollution over time. Heavy metal source analysis coupled with correlation analysis and principal component analysis (PCA) was used as a data reduction technique, which reveals that the heavy metal pollution in marine coastline might originate from redox reactions (FeMn coupling) and anthropogenic sources.

Snapshot of the pollution-driven metabolic and microbiota changes in Carassius gibelio from Bucharest leisure lakes

In the last decades, increased intakes of contaminants and the habitats' destruction have produced drastic changes in the aquatic ecosystems. The environmental contaminants can accumulate in aquatic organisms, leading to the disturbance of the antioxidant/prooxidant balance in fish. In this context, we evaluated the level of organic, inorganic and microbiological pollutants in four leisure lakes (Chitila, Floreasca, Tei and Vacaresti) from Bucharest, the largest city of Romania, in order to compare their effects on hepatopancreas and gills metabolism and antioxidant defense mechanisms in Carassius gibelio, the most known and widespread freshwater fish in this country. The lowest level of oxidative stress was recorded in the case of fish collected from the Vacaresti lake, a protected wetland area where aquatic organisms live in wild environmental conditions. In contrast, significant oxidative changes were observed in the hepatopancreas and gills of fish from the Chitila, Floreasca and Tei lakes, such as reduced glutathione S-transferase activity and glutathione level, and increased degree of lipid peroxidation, being correlated with elevated levels of pesticides (such as 2,4'-methoxychlor) and Escherichia coli load in these organs. Although different patterns of pollutants' accumulation were observed, no important interindividual variations in cytosine methylation degree were determined. In conclusion, the presence and concentrations of metals, pesticides and antibiotics varied with the analyzed tissue and sampling site, and were correlated with changes in the cellular redox homeostasis, but without significantly affecting the epigenetic mechanisms.

Phytoremediation capability of Typha latifolia L. to uptake sediment toxic elements in the largest coastal wetland of the Persian Gulf

The present study evaluated the status of sediment toxicity and pollution, and the phytoremediation capability of Typha latifolia L. (TlL) within the largest coastal wetland in the southwest of Iran, the Shadegan International Wetland. In eight sampling sites, covering the entire wetland, the concentration of six toxic elements (As, Cr, Cu, Ni, Pb, and Zn) in the surface sediment, root, and stem of TlL were measured. The results indicated that mean concentrations of Cr, Cu, Pb, and Zn were found to be higher than those in the local background, which likely indicates anthropogenic sources of these elements. Due to the presence of a nearby landfill, the results of modified pollution index (MPI) and aggregate toxicity index (ATI) indicated a moderately-heavily polluted level and moderate to high toxic degree, respectively. However, the medium-low level of toxicity toward living of organisms (21 % probability) was detected based on the assessment of the Sediment Quality Guidelines (SGQ). The results of our study indicate that the root and stem tissues of TlL are capable of acting as an indicator of Cu/Pb/Zn and Zn pollution in sediment, respectively. Considering the potential of phytoremediation, TlL represented both phytostabilization and phytoextraction capabilities for Pb and Zn and a significant increase was observed in the phytoremediation capability by increasing the distance from the landfill area. According to the results of the metal accumulation index (MAI) and comprehensive bioconcentration index (CBCI), TlL grown in the study area showed an acceptable performance in the accumulation of multiple toxic elements compared to that in Turkey, India, and Poland. Overall, TlL is a good candidate for the phytoremediation of sediments contaminated by Pb and Zn.

Potentially hazardous elements in sediments and Ceratophyllum demersum: an ecotoxicological risk assessment in Miliç Wetland, Samsun, Türkiye

Potentially hazardous elements (PHEs) are non-biodegradable and accumulate in places like water, soil, and plants where they endanger environmental health. There are a considerable number of wetlands having both national and worldwide importance in Türkiye. Regarding PHE accumulation, sediments and Ceratophyllum demersum were examined in the Miliç Wetland (MW), situated in a basin with intense hazelnut and rice farming, which is next to the international highway on the Central Black Sea Coast of Türkiye. The quantification of PHEs in the study subjects was undertaken using a validated inductively coupled plasma-mass spectrometry (ICP-MS) method, and mean concentrations (mg/kg) of PHEs in the sediments were in the order of Al (13,133) > Fe (10,790) > Mn (205.84) > Cu (17.95) > Cr (16.40) > Zn (15.55) > Ni (11.74) > Pb (9.17) > Co (6.30) > As (2.07) > Cd (0.19). The ecotoxicological risk was assessed using sediment quality guidelines (SQGs) and certain geological indices, indicating mostly low ecological risk, low pollution, and no hazardous risk. Based on the modified hazard quotient (mHQ) classification of values, Ni showed low contamination, while Cd, Pb, As, and Cu displayed very low contamination, and Zn presented minor contamination. The findings of total lifetime cancer risk (LCR), hazard quotient (HQ), and hazard index (HI) identified that exposure of adults or children to sediments containing PHEs would not represent a major health risk. As a recommendation, it is necessary to avoid the direct entrance of agricultural pesticides and fertilizers to enhance the sediment quality of the MW. Since the highway was constructed close to MW, this is considered a significant source of human-caused pollution. Consequently, all PHEs analyzed, except for Cd, displayed a bioconcentration factor (BCF) value of more than 1000, indicating that Ceratophyllum demersum is a promising plant for phytoremediation in PHE-polluted ecological systems involving wetlands, and it can efficiently be employed as an indicator species in biological screening investigations.

Ecological and Health Risk Assessments of Heavy Metals Contained in Sediments of Polish Dam Reservoirs

This study aimed at investigating the distribution of heavy metals (HMs: Zn, Pb, Cd, Ni, Cr, and Cu) in the bottom sediments of 28 reservoirs covered area of Poland. The paper evaluates the pollution of sediments with HMs and their potential toxic effects on aquatic organisms and human health on the basis of results provided by the Chief Inspectorate of Environmental Protection in Poland. The average concentrations of HMs in the bottom sediments of the reservoirs were as follows: Cd < Ni < Cr < Cu < Pb < Zn. (0.187, 7.30, 7.74, 10.62, 12.47, and 52.67 mg∙dm−3). The pollution load index values were from 0.05 to 2.45. They indicate contamination of the bottom sediments in seven reservoirs. The contamination-factor values suggest pollution with individual HMs in 19 reservoirs, primarily Cr, Ni, Cu, and Pb. The analysis showed that only two reservoirs had the potential for toxic effects on aquatic organisms due to high concentrations of Cd and Pb. The hazard index values for all the analyzed HMs were less than one. Therefore, there was no non-carcinogenic risk for dredging workers. The reservoirs were divided into two groups in terms of composition and concentration values. Reservoirs with higher concentrations of HMs in bottom sediments are dispersed, suggesting local pollution sources. For the second group of reservoirs, HMs’ concentrations may be determined by regional pollution sources. The analysis showed that Pb, Zn, and Cd concentrations are higher in older reservoirs and those with higher proportions of artificial areas in their catchments. Concentrations of Ni, Cu, and Cr are higher in reservoirs in south Poland and those with higher Schindler’s ratios.