Heavy metals in Yeniçağa Lake and its potential sources: soil, water, sediment, and plankton

Evaluation of some heavy metals and selenium pollution in Karataş Lake (Burdur/Türkiye) using various pollution indices and statistical analysis

Wetland face environmental problems due to some reasons such as drought, rapid population and rapid developments in technology. Karataş Lake is located within the Lakes Region in Türkiye and has also of great economically, ecologically and ornithologically importance. Unfortunately, it completely dried out in 2021 due to sufficient rainfall, groundwater withdrawal and global climate change. In 2022, the lake started to hold water again. This study is important because it is one of the last studies before the lake dries up and first study to evaluate some heavy metals and selenium pollution using some indices. In this study, which was carried out between October 2019-July 2020, some heavy metals and selenium concentrations were determined in water of Karataş Lake seasonally and evaluated pollution degree of lake water using some indices and statistical analysis. Water temperature, pH, electrical conductivity and dissolved oxygen levels were measured in situ using YSI 556 MPS. For heavy metal analysis, water samples were taken, acidified to a pH of <2, stored at 4 °C and analyzed directly using ICP-OES (Agilent 5110). Pb and Se in all seasons were below detection limit. The analyzed metals sorted as; Cd < Mo < Cr < Cu < Mn < Zn < Ni < Fe. Generally, heavy metals were increased in autumn and decreased in spring. According to some water quality standards for drinking water, Fe levels were higher than the permissible levels for drinking water in all seasons (TSE, 2005; EPA, 2018; EU, 2020), Mn in autumn (TSE, 2005; EPA, 2018; EU, 2020), Ni in autumn and summer (TSE, 2005; EU, 2020). Water Quality Index (WQI), Heavy Metal Pollution Index (HPI) and Heavy Metal Evaluation Index (HEI) values were calculated in Karataş Lake to determine pollution degree. Depend on WQI results, lake water was in good category in autumn, winter and spring while poor category in summer. The lake water samples based on HPI and HEI values are in the low contamination category. The lake is still struggling with environmental problems. If necessary precautions are not taken for the future of the lake, the lake may dry out again. The results of this study will help the authorities in terms of preventing re-drying, sustainability of the lake and management of the region. This study will be also a reference for future studies.

Assessment of potentially hazardous elements in soils of the Boyacá industrial corridor (Colombia) using GIS, multivariate statistical analysis, and geochemical indexes

In the industrial corridor of Boyacá, Colombia, population growth is accompanied by anthropogenic activities such as industrial operations, vehicle exhaust fumes, mining, smelting, atmospheric deposition, and excessive use of chemical products to promote crop growth. These activities are known to have a significant impact on urban and rural soils, contributing significantly to elevated concentrations of potentially hazardous elements in the environment. This industrial corridor is an area of economic and social development that needs to provide reference information that will allow us to know the state of soil quality to preserve and manage the public and geoenvironmental health of this region. Anthropogenic activities have contributed to the accumulation of potentially hazardous elements in the environment, affecting various levels of life and creating risks with economic and social implications. However, igneous activity or detrital deposition also enriches soils and creates geochemical anomalies in specific locations. In these cases, the identification of potentially hazardous elements involves the determination of likely sources of contamination and their relationship to the geological setting. In this study, the concentrations of As, Cd, Pb, Mn, Fe, Zn, Hg, Cu and Ni were determined in eighty-one soil samples from the Boyacá industrial corridor (Colombia). The sequential trend of the concentrations of potentially hazardous elements was as follows: Fe > Mn > Zn > Ni > Cu> Pb > As > Cd > Hg. Furthermore, the application of spatial analysis criteria in GIS software with multivariate statistical tools and geochemical indices allowed the identification of anthropogenic and geogenic sources. Most of the potentially hazardous elements were found in soils exposed to industrial and agricultural activities, except for iron. This element showed low variability in all samples, regardless of the geological formations. Due to the lack of reference values for potentially hazardous elements in Colombia, the concentrations were compared with the environmental standards of the Environmental Protection Agency (EPA) and the Ecuadorian Ministry of Environment, Water and Ecological Transition (MAE). The results demonstrate the complexity of the soil and represent the first exploratory study of potentially hazardous elements in this industrial corridor. These results are the starting point for the establishment of geochemical background lines in Colombia and for inspection policies for areas where productive activities converge.

How phytoplankton biomass controls metal(loid) bioaccumulation in size-fractionated plankton in anthropogenic-impacted subtropical lakes: A comprehensive study in the Yangtze River Delta, China

Phytoplankton biomass can significantly affect metal(loid) bioaccumulation in plankton, but the underlying mechanisms are still controversial. We investigated the bioaccumulation of eight metal(loid)s (As, Co, Cu, Hg, Mn, Pb, Se, and Zn) in three size categories of planktonic organisms - seston (0.7-64 μm), mesozooplankton (200-500 μm), and macrozooplankton (>500 μm) - sampled from six freshwater lakes in two seasons in the Yangtze River Delta, China. Our results highlight phytoplankton biomass is the major driver on metal(loid) bioaccumulation in the studied anthropogenic-impacted subtropical lakes, mainly via affecting site-specific water physiochemical characteristics and plankton communities. However, such impact is highly dependent on chlorophyll a (Chl-a) concentration. The bioaccumulation of metal(loid)s in size-fractionated plankton declined significantly with increasing phytoplankton biomass when Chl-a was below ∼50 μg L^-1, mainly owing to the reduced metal(loid) bioavailability and subsequent bioaccumulation at more productive sites (with elevated pH and dissolved organic carbon), rather than algal bloom dilution. To a lesser extent, phytoplankton growth dilution and the smaller body-size of zooplankton at more productive sites also contributed to the lower metal(loid) bioaccumulation. The bioaccumulation of metal(loid)s was enhanced under severe algal bloom conditions (when Chl-a concentration was higher than ∼50 μg L^-1). Although the underlying mechanisms still require further investigations, the potential risks of metal(loid) bioaccumulation under severe algal bloom conditions deserve special attention.

Assessment of the Anthropogenic Impact and Distribution of Potentially Toxic and Rare Earth Elements in Lake Sediments from North-Eastern Romania

Chemical analysis was performed on sediment samples collected in two sampling sessions (July and October) from Podu Iloaiei Dam Lake, one of the most important water resources used for aquaculture in north-eastern Romania. The concentration of 15 trace elements (TEs), 8 refractory elements (REs), and 15 rare earth elements (REEs)—determined using inductively coupled plasma mass spectrometry—showed variability largely dependent of the sampling points and collection time. Manganese was the most abundant TE, V and Cr were the most abundant REs, while Ce was one of the most abundant REEs. The cerium negative anomaly and Gd positive anomaly were observed in the Chondrite-normalized distributions. In October, the Ce anomaly showed significant negative correlation with Mn, emphasizing the water body oxidation potential. The identified positive Gd anomaly was most likely associated with the use of Gd-chelating agents in magnetic resonance imaging in Iasi, the largest medical hub in north-eastern Romania. Principal component analysis extracted three factors explaining 96.0% of the observed variance, i.e., rock weathering, leaching from soil surface, contributions from urban stormwater and atmospheric deposition (50.9%), pedological contributions (23.7%), and mixed anthropogenic sources (e.g., traffic, waste discharge, agricultural activities; 21.4%). The evaluation of pollution indices highlighted low and moderate degrees of contamination for most of the elements and a considerable degree of contamination for Cd. Assigned Cd sources included fertilizers and pesticides used in the near agricultural areas or the high traffic road located near the lake. Since contamination of aquatic ecosystems with harmful elements is a human health concern, further monitoring of specific vectors in the food chain of the investigated dam lake will be of the utmost importance.

Streptomyces ureilyticus sp. nov. and Streptomyces mesophilus sp. nov., two novel Actinobacteria with antimicrobial activity isolated from lake sediment

Two novel Actinobacteria, designated strains YC419^T and YC504^T, were isolated from a sediment sample collected from Lake Yeniçağa, Bolu Province, Turkey. Chemotaxonomic and morphological characteristics of isolates were found to be typical of members of the genus Streptomyces. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain YC419^T was most closely related to Streptomyces vastus NBRC 13094^T (99.0 %) and 'Streptomyces xiangluensis' NEAU-LA29 (98.6 %), and strain YC504^T was to most closely related to Streptomyces caldifontis NCCP-1331^T (98.6 %) and Streptomyces indicus IH32-1^T (98.0 %). The cell walls of the two strains contained ll-diaminopimelic acid as the diagnostic diamino acid and the whole-cell hydrolysates were glucose, mannose and ribose. The predominant menaquinones were MK-9(H₈) and MK-9(H₆) in both strains. The major polar lipids of strain YC419^T were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol, while strain YC504^T had a similar profile but lacking diphosphatidylglycerol. The G+C contents of the genomic DNAs were 69.6 and 70.3 mol% for strains YC419^T and YC504^T, respectively. The phenotypic and genotypic data indicated that these two strains were readily distinguished from one another and the type strains of the other species classified in the genus Streptomyces. Therefore, the strains are suggested to represent two novel species of the genus Streptomyces, for which the names Streptomyces ureilyticus sp. nov. and Streptomyces mesophilus sp. nov. are proposed. The type strains are YC419^T (=DSM 102299^T=KCTC 39757^T) and YC504^T (=DSM 102300^T=KCTC 39756^T), respectively.

Correlation profile of the heavy metal distribution in the Pontastacus leptodactylus tissues

Arsenic (As), copper (Cu), nickel (Ni), zinc (Zn), manganese (Mn), lead (Pb), iron (Fe), aluminum (Al), cadmium (Cd) and chromium (Cr) accumulations were evaluated in the gills, hepatopancreas, exoskeleton, and muscles of Pontastacus leptodactylus (crayfish) (Eschscholtz, 1823). The highest metal accumulation was observed in the gills and hepatopancreas. It was detected a negative correlation between Cr-Pb, As-Cr in the muscle tissue. All other metals were displayed positive correlations with each other in the gills, hepatopancreas, and exoskeleton. Strong positive correlations were determined between Ni-Cd and As-Pb in the gills, Ni-Cd, As-Pb and Al-Zn in the hepatopancreas, Zn-Mn and Fe-Cu in the exoskeleton, Ni-Cd, As-Pb, Zn-Mn, Al-Mn, Fe-Cu and Al-Zn in the muscle (r= 1.000). PCA and cluster analysis generally were supported the correlations observed. The correlations between divalent metals may be expressed by the role of divalent metal transporter 1 (DMT1) in the gathering of these metals.

Heavy metal concentrations in roadside plants (Achillea wilhelmsii and Cardaria draba) and soils along some highways in Hamedan, west of Iran

The present study was conducted to analyze the effects of traffic volumes on Cd, Cu, Pb, Ni, and Zn contents in roadside soils and in two dominant herbaceous species (Achillea wilhelmsii and Cardaria draba) along highways and to evaluate the dynamic characteristics of these elements and their accumulation by the aerial parts and roots of these herbaceous species. The plant samples were collected along 700 m of a 9-km segment of each of the three major highways in Hamedan Province (West Iran) with different traffic volumes: Hamedan-Goltapeh (HG), Hamedan-Razan (HR), and Hamedan-Kermanshah (HK). The results indicated that the mean contents of Cd, Cu, Pb, Ni, and Zn in the soil samples were 0.26, 18.74, 14.98, 18.21, and 62.25 mg kg^-1, respectively. Furthermore, the mean contents of elements (mg kg^-1) in aerial parts of A. wilhelmsii were 0.16 for Cd, 4.52 for Cu, 1.91 for Pb, 1.70 for Ni, and 44.80 for Zn, while in the aerial part samples of C. draba, the concentrations (mg kg^-1) and the mean contents were 0.16, 2.29, 2.58, 1.60, and 31.29, respectively. This meant that the traffic volume affected the contents of the metals in the soil and the herbaceous species. The metal content in herbaceous tissues varied significantly between plant species. A. wilhelmsii tended to accumulate the metals in the roots while C. draba retained them mostly in the aerial parts. The significant positive correlations of Cd, Cu, Ni, and Zn content in root and aerial parts of the herbaceous plant with those found in the soil samples showed the potential of the studied species for application in biomonitoring studies. Comprehensive analysis (effect of traffic volumes and relationships between the content of elements in plant tissues and soil samples) indicated that Cu in both herbaceous plants was mainly derived from soil, while A. wilhelmsii absorbed Cd and C. draba absorbed Zn mainly through the stomata from atmospheric depositions. Without considering atmospheric depositions due to intense traffic volumes, in A. wilhelmsii, the translocation factor (TF) values of Cu and Zn were 1.06 and 1.44, respectively and in C. draba, the TF values of Cd, Cu, and Pb were 1.06, 1.09, and 1.13, respectively, thus suggesting that both herbaceous species had high potentials for transferring metals from the roots to aerial parts.

Distribution and relationship between antimicrobial resistance genes and heavy metals in surface sediments of Taihu Lake, China

Heavy metals, pharmaceuticals, and other wastes released into the environment can significantly influence environmental antibiotic resistance. We investigated the occurrence of 22 antimicrobial resistance genes (ARGs) and 10 heavy metal concentrations, and the relationship between ARGs and heavy metals in surface sediment from seven sites of Lake Taihu. The results showed significant correlations (p < 0.05) between sediment ARG levels, especially for tetracycline and sulfonamides (e.g., tet(A), tet(D), tet(E), tet(O), sul1, sul2 and int-1) and specific heavy metals (Fe, Mn, Cr, Cu, Zn, among others) in the Lake. In the surface sediments, heavy metals showed an interaction with resistance genes, but the strength of interaction was diminished with increasing depth. For most of the heavy metals, the concentration of elements in the top sediments was higher than that in other depths. Tetracycline resistance genes (tet(A), tet(B), tet(D), tet(E) and tet(O), β-lactam resistance genes (SHV, TEM, CTX, OXA and OXY) and sulfonamide resistance genes (sulA, sul1, sul2, sul3 and int-1) were detected. They showed a trend which inferred a statistically significant increase followed by decreases in the relative abundance of these ARGs (normalized to 16S rRNA genes) with increasing depth. This study revealed that tet(A), tet(O), TEM, OXY, int-1, sul1 and sul3 were widespread in surface sediments with high abundance, indicating that these genes deserve more attention in future work.

Concentrations of Arsenic and Boron in Water, Sediment and the Tissues of Fish in Emet Stream (Turkey)

In this study, the concentrations of arsenic and boron were determined in the water and the sediment, as well as in the muscle tissues of Squalius cephalus, Alburnoides bipunctatus, Barbus plebejus and Capoeta tinca from Emet Stream. The fish samples were caught in May 2011 and September 2012. The metal concentrations in the water samples were as follows: arsenic was 137.1-1002 µg L^-1, and boron was 2421-14490 µg L^-1. The metal concentrations in the sediment samples were as follows: arsenic was 14.51-3317.1 mg kg^-1, and boron was 14.22-1014.01 mg kg^-1. The mean tissue concentration of arsenic was lower than the TFC and WHO limits. Boron has been identified in fish tissues at concentrations between 0.26 and 2.96 mg kg^-1. The bioaccumulation in the muscle tissues of all fish species caught from Emet Stream did not exceed the limit values.

Trace metals content in soils along the state road 51 (northeastern Poland)

The aim of the study was to determine concentrations of some trace elements (lead, cadmium, chromium, and nickel) in soils along State Road 51 leading from Olsztyn to Olsztynek, northeastern Poland. The traffic flow had a significant effect on the content of heavy metals in soils lying along the road. Further away from the road, and under a lower traffic flow intensity, the amounts of contaminants originating from the motor traffic decreased. There was a pine forest growing by the road near Olsztyn, which served as a buffer zone for all the analyzed heavy metals. At all the sampling locations, the content of chromium was approximately the same as its natural concentration. The statistical analysis demonstrated that there was a strong negative correlation between the concentrations of nickel, lead, chromium, and cadmium in soils and the distance from the road. The biggest differences in the content of an individual element were determined for lead and the smallest ones--for cadmium. Emissions of trace elements depended on the differences in the traffic flow intensity, number, type, and speed of vehicles and on the atmospheric conditions as well as the distribution of buildings.

What factors determine trace metal contamination in Lake Tonga (Algeria)?

A study of trace metal (TM) contamination was conducted at Lake Tonga (Algeria), a site surrounded by several indirect contamination point sources such as an abandoned mine and steelworks. Studying two sampling sites over four seasons, we were able to depict the spatial and temporal variability of TM contamination in the lake. Among the seven TM examined (Pb, Cd, Fe, Zn, Ni, Cu, and Cr), only Fe, Pb, and Cd showed concentrations significantly higher than the site's geological background. The contamination index (sediment concentration/background concentration) calculated for these three TM (Cd = 1.9 ± 1.6, Fe = 6.8 ± 1.8, and Pb = 3.3 ± 2.6) clearly indicated anthropogenic contamination. Sediment TM contamination differed both between sampling sites and seasons despite environmental variables (e.g., oxygen and pH) being similar, thus suggesting different TM contamination sources. Fe contamination was high at the two sampling sites and over all studied seasons, possibly indicating general lake-scale Fe contamination, probably related to atmospheric deposition of steelworks emissions both on the lake and within the watershed. Lake tributaries were further suspected of channeling Fe contamination from the watershed into the lake. On the other hand, the sampling site close to the outlet was especially rich in Cd and Pb typically reflecting contamination by mine wastes. The indirect connection between the abandoned mine and the lake indicates that runoff of mine leachates through groundwater was likely a candidate in explaining the specificity of the TM contamination in this part of the lake. This study provides insights for management of TM contamination by addressing both spatial and temporal variability within the lake as well as differences in contamination sources.

Assessment of metal concentrations in two Cyprinid fish species (Leuciscus cephalus and Tinca tinca) captured from Yeniçağa Lake, Turkey

This study was performed to investigate certain major and toxic metal concentrations in muscle, gill and liver tissues of two Cyprinid species (Leuciscus cephalus, Tinca tinca). Generally liver and gill tissue exhibited higher metal concentrations than did muscle. The highest metal concentrations found in tench and chub muscle tissues were determined to be Al (59.01-108 mg kg(-1)), Zn (45.23-57.81 mg kg(-1)), Fe (9.23-16.03 mg kg(-1)) and Ba (3.50-2.69 mg kg(-1)) respectively. The level of metal accumulation is evaluated for potential risk to human health based on international standards. Zinc, lead and arsenic values of muscle tissues of the fishes were found to be above the allowed limits for human consumption.