Quality Of Bottom Sediments Research Articles

ORGANOCHLORINE PESTICIDES POLLUTION OF THE BOTTOM SEDIMENTS OF NAKHODKA BAY AND PARTIZANSKAYA RIVER

Link for citation: Mazlova E.A., Blinovskaya Ya.Yu., Sokolova L.I., Tursunova G.Sh. Organochlorine pesticides pollution of the bottom sediments of Nakhodka bay and Partizanskaya river. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 25-35. In Rus. Relevance. The new data on the organochlorine pesticides pollution of the bottom sediments of Nakhodka bay and Partizanskaya river were obtained in 2020–2021. The objective of the article is to report the organochlorine pesticides pollution level of the bottom sediments and to define the possible sources of organochlorine pesticides in the marine environment. Techniques: sample collection of bottom sediments, Gas Chromatography Mass Spectrometry analysis of samples, Gas-liquid Chromatography method with electronic capture detector, statistical processing, assessment of the organochlorine pesticides contamination of sediments. Results. The new data were obtained on the organochlorine pesticides concentrations in Nakhodka bay in 2020–2021. The previous data on the studied area are described. The concentration of HCH pesticides (α- , β- and γ-HCH), DDT and its metabolites was analyzed. It was found that the concentration of α- , β- HCCH and DDT in bottom sediments increased in 2021.To determine the quality of bottom sediments, the average annual values of organochlorine pesticides concentrations in the bottom sediments gathered during the field works were compared with the quality guidelines. There are no approved quality guidelines for maximum permissible concentrations of pollutants in bottom sediments in the Russian Federation. For this reason, we used the quality guidelines applied in foreign countries («Dutch sheets» (Neue Niederlandische Liste. NNL) and Canadian quality standards for marine and estuarine bottom sediments (Canadian Sediment Quality Guidelines, CSQGs). Possible sources of organochlorine pesticides in the marine environment were analyzed. The results of this work showed that despite the ban on the use of these substances, these pesticides are included in the multiple compounds used in different industries and continue to enter and accumulate in the marine environment.

Hydroecological data recovery using artificial intelligence

Artificial neural networks and genetic algorithms have been tested for the restoration of missed hydroecological indicators (hydrological water quality parameters and bottom sediment quality parameters). Algorithms have been developed for recovering missing hydroecological data in the presence and absence of observation data from points upstream and downstream. Neural network models for the restoration of water quality indicators and bottom sediments were tested on the example of the catchment basin of the Bayda and Kidysh rivers in the territory of the Republic of Bashkortostan.

Impacts of Nile tilapia cage culture on water and bottom sediment quality: The ability of an eutrophic lake to absorb and dilute perturbations

AbstractEnvironmentally sustainable aquaculture depends on accurate understanding of the impacts of aquaculture‐derived organic matter (AOM) and the ability of aquaculture systems to absorb and dilute perturbations. To this end, the present study assessed the impacts of AOM from cage culture of Nile tilapia on the ecology of Lake Victoria, Kenya, using fish cages near Anyanga Beach in Siaya County from December 2018 to October 2019. Four locations were surveyed for organic loadings from cage cultures, located 0, 50, 150 and 500 m (as a control site) away from the cages. The cage aquaculture produced increased P and N concentrations near the cages and a decreased N:P molar ratio. These changes stimulated algal growth which, in turn, affected the water quality. The organic material accumulated on the bottom under the cages, increasing the benthic BOD (BOD, >10 mg/g), a sensitive indicator of the ecological footprint of the cage aquaculture. Further, the negative ORP observed in the benthic layer suggested anoxic bacterial metabolism, possibly causing build‐up of sulphides and methane. These changes altered the abundance and composition of both limnetic and benthic communities. At the beginning of the study, 22 zoobenthic taxa existed around the cages and 18 at the reference sites. Only 3 saprophilous taxa, chiefly gastropods (Physellaspp.), bivalves (Sphaeriumspp.) and oligochaetes (Tubifexspp.) were present at the cage site and 17 at the reference site at the end of the culture period. The Shannon diversity index exhibited a declining tendency with the length of culture period at the cage site, signifying a negative impact of aquaculture on biodiversity. The water quality recovery after cage disturbance is rapid (<4 months), noting there was no significant difference in the water quality recorded at the cage site and the other sampling sites after a fallow period of 4 months. However, the recovery of the sediment and meiofauna was far from complete at the end of this period. Moving the cages slightly (50–100 m) away from the former location may allow the benthic communities to recover and alleviate the problem. Further, the fallowing period, particularly for the Anyanga Beach site, should be extended from four to at least 5 months to allow for the environment to recover. With the rapid increase of cage fish farming in the African Great Lakes Region and with the potential for its occurrence in other lakes, there is a need to develop regulations to guide the industry, as well as the need for continuous monitoring of the environment, in order to provide information to guide investments and ensure sustainable cage farming.

DYNAMICS OF CHEMICALS IN RIVER BOTTOM SEDIMENTS ON THE TERRITORIES IMPACTED BY THE OIL INDUSTRY

Background. Two thirds of all oil reserves of the Russian Federation are concentrated on the territory of Western Siberia. Field work, production and distribution of petroleum products at the oil and gas field are the main reasons for the negative impact on the ecosystems of the northern territories.
 Purpose. The purpose of this study is to evaluate the chemical pollution dynamics of the rivers’ bottom sediments in the Middle Ob region, the region of the Samotlor field.
 Materials and methods. Based on the chemical analysis of the sediment samples, concentrations and total values of the following chemical elements were determined: manganese, copper, nickel, lead, chromium, zinc, iron sulfate ions, chloride ions, petroleum products, mercury. Based on the results of long-term studies of the chemical analysis dynamics of the bottom sediments in the Ob, Agan, and Vakh rivers, a correlation and regression analysis of the studied indicators was carried out.
 Results. The results of the correlation analysis suggest the existence of negative and positive correlations in the studied indicators. Regression analysis of the migration of chemical elements in sediment samples during the study period shows significant fluctuations in the total concentration of chemical elements in sediments, but there is a general tendency to decrease their concentration in sediments.
 Conclusion. Analyzing the ecological state of the studied rivers by the quality of bottom sediments, in general, we can conclude that they are in stable condition. During the study period, there has been a positive dynamics in the concentration of chemical elements in bottom sediments.

Metal contamination in sediments of dam reservoirs: A multi-facetted generic risk assessment

The quality of bottom sediments is a key factor for many functions of dam reservoirs, which include water supply, flood control and recreation. The aim of the study was to combine different pollution indices in a critical generic risk assessment of metal contamination of bottom sediments. Both geochemical and ecological indices reflected that sediment contamination was dominated by Zn, Pb and Cd. The ecological risk indices suggested a high riks for all three metals, whereas human health risks were high for Pb and Cd. An occasional local contamination of sediments with Cr and Ni was revealed, although at levels not expected to cause concerns about potential ecological or health risk. Sediments from the Rybnik reservoir for Cu only revealed a high potential ecological risk. EF turned to be as being the most useful, whereas TRI (∑TRI) was the most important ecological index. All multi-element indices suggested similar trends, indicating that Zn, Pb and Cd taken altogether had the greatest impact on the level of sediment contamination and posed the greatest potential ecological and health risks to organisms. The use of sequential BCR extraction and ecotoxicity analyses allowed for a multi-facetted generic risk assessment of metals in sediments of dam reservoirs.

Quality of Bottom Sediments of Sołtmany Lake (Masurian Lake District, Poland) in the Light of Geochemical and Ecotoxicological Criteria—Case Study

The quality of bottom sediment is important for the condition of aquatic environments. High levels of potentially harmful components in sediments negatively affect the quality of surface water environments. Lake bottom sediments are commonly used to control the quality of the environment in terms of both heavy metals and harmful organic compounds. This paper presents new data on the compositions of bottom sediments from Sołtmany Lake, located in the Masurian Lake District (Poland). The aim of this study was to determine the physicochemical properties of bottom sediments and to assess their quality based on geochemical and ecotoxicological criteria. The field study was conducted in July 2021. Thirty sediment samples were collected for analysis from six study sites located in the upper central and lower part of the reservoir. Contamination of the bottom sediments with trace metals was determined on the basis of the geoaccumulation index (Igeo), while an ecological risk assessment was carried out on the basis of calculated values of TEC (Threshold Effect Concentration) and PEC (Probable Effect Concentration) indices. The study shows that the concentration of trace metals in sediments was characterised by slight variation and that the maximum values did not exceed: 1.1 mg·kg−1 for Cd, 8.7 mg·kg−1 for Cr, 10.9 mg·kg−1 for Cu, 7.7 mg·kg−1 for Ni, 12.9 mg·kg−1 for Pb and 52.3 mg·kg−1 for Zn. The analyses further showed that the concentration of trace elements in the sediment surface layer increased in the following order: Zn > Pb > Cu > Ni > Cr > Cd. The maximum pH value of H2O was 7.1, while that of KCl was 7.0. The maximum values of Corg, Ntot, P2O5, K2O and Mg were, respectively: 6.1 g·kg−1, 1.4 g·kg−1, 40.2 mg·100 g−1, 31.2 mg·100 g−1 and 35.1 mg·100 g−1. The assessment of the degree of lake pollution is essential for the conservation of biodiversity and the organisation of environmental management activities.

Monitoring of chemical and biological composition of bottom silt (literature review)

The work is devoted to the study of the formation of bottom sediments and silt, their impact on the state of aquatic ecosystems, effective research methods and their practical application. Due to the continuous anthropogenic load, heavy metals, polycyclic aromatic hydrocarbons and other pollutants constantly accumulate in the silt and bottom formations. They undergo various chemical processes that can produce compounds that are even more toxic. The accumulation of this complex of pollutants subsequently becomes a source of secondary pollution, affecting the quality of water in reservoirs, reducing the species diversity of aquatic organisms and, through migration and movement along food chains, negatively affecting the condition of plants, animals and people, ultimately violating the processes of self-purification. Silt and bottom sediments thus become indicators of water pollution. On secondary deposits, biological processes are inhibited, anaerobic conditions arise, acidity increases, which contributes to the constant release and entry of harmful gases into the atmosphere. One of the main consequences of this process is the greenhouse effect and the violation of the heat balance. One of the ways to monitor bottom sediments is bio testing. In this method, crustaceans are chosen as test organisms because of their sensitivity to pollution, wide distribution. Bio testing can be used as an independent method for assessing the state of aquatic ecosystems, and in their integral assessment. Now in Russia there is no system for assessing the quality of bottom sediments, which greatly complicates the assessment of the state of surface water bodies and the prediction of negative processes. Thus, data on the composition of pollutants in silt and bottom sediments are not applicable for ecological characterization. Therefore, it seems necessary to create a unified methodology and establish interdepartmental communication of specialists in order to fully assess the pollution of water bodies and respond in time to threatening levels.

Utilization of Pollution Indices, Hyperspectral Reflectance Indices, and Data-Driven Multivariate Modelling to Assess the Bottom Sediment Quality of Lake Qaroun, Egypt

Assessing the environmental hazard of potentially toxic elements in bottom sediments has always been based entirely on ground samples and laboratory tests. This approach is remarkably accurate, but it is slow, expensive, damaging, and spatially constrained, making it unsuitable for monitoring these parameters effectively. The main goal of the present study was to assess the quality of sediment samples collected from Lake Qaroun by using different groups of spectral reflectance indices (SRIs), integrating data-driven (Artificial Neural Networks; ANN) and multivariate analysis such as multiple linear regression (MLR) and partial least square regression (PLSR). Jetty cruises were carried out to collect sediment samples at 22 distinct sites over the entire Lake Qaroun, and subsequently 21 metals were analysed. Potential ecological risk index (RI), organic matter (OM), and pollution load index (PLI) of lake’s bottom sediments were subjected to evaluation. The results demonstrated that PLI showed that roughly 59% of lake sediments are polluted (PLI > 1), especially samples of eastern and southern sides of the lake’s central section, while 41% were unpolluted (PLI < 1), which composed samples of the western and western northern regions. The RI’s findings were that all the examined sediments pose a very high ecological risk (RI > 600). It is obvious that the three band spectral indices are more efficient in quantifying different investigated parameters. The results showed the efficiency of the three tested models to predict OM, PLI, and RI, revealing that the ANN is the best model to predict these parameters. For instance, the determination coefficient values of the ANN model of calibration datasets for predicting OM, PLI, and RI were 0.999, 0.999, and 0.999, while they were 0.960, 0.897, and 0.853, respectively, for the validation dataset. The validation dataset of the PLSR produced R2 values higher than with MLR for predicting PLI and RI. Finally, the study’s main conclusion is that combining ANN, PLSR, and MLR with proximal remote sensing could be a very effective tool for the detection of OM and pollution indices. Based on our findings, we suggest the created models are easy tools for forecasting these measured parameters.

The quality of bottom sediments in small water reservoirs located in agricultural watersheds

Silting of water reservoirs by sediments detached through soil erosion is a serious water management problem. One of the solutions is direct application of sediments to the soil. The aim of the paper is to monitor the quality of bottom sediments taken from selected water reservoirs in the eastern Slovakia (Hervartov, Nižný Žipov, Byšta) and to evaluate their quality according to legislation. The results showed that the concentrations of total nitrogen, phosphorus and potassium in sediments are higher than in soils taken from the vicinity of reservoirs.Simultaneously, it was confirmed that the sediment in the evaluated reservoirs meets the physicochemical parameters according to the Act No. 188/2003 Coll. for direct application to the soil.

Effects of Aquacultural Practices on the Sediment Characteristics of Certain Type of Earthen Fishponds

The effect of aquacultural practices on the bottom sediment quality of six selected earthen fishponds in Ife North Local Government Area of Osun State was investigated for a period of two years. The fishponds were grouped with regard to fertilization practice and water flowage regime into three sets comprising two fertilized non-flow-through ponds (FNF); two fertilized flow-through ponds (FF) and two unfertilized flow-through ponds (NFF). The investigated sediment quality parameters include color and textural composition, salinity parameters, major ions, organic parameters and heavy metals using standard methods. The parameters were not statistically different (P > 0.05) for the three sets of fishponds with the exception of calcium which was significantly available in the fertilized flow-through pond. The fertilized ponds were however richer in nutrient and of better drainage quality than the unfertilized ponds. The parameters with higher mean in the fertilized ponds (FNF and FF) were 16% higher on average and flow-affected parameters were 67% higher on average in the flow-through ponds (FF and NFF), of which 7.00-fold higher lead concentration contributed most to this situation. Of these parameters, cations, anions, micronutrients were found to be of highest mean concentration in fertilized flow-through ponds. However, the presence of significant levels of calcium ions as well as minimal accumulation of clay, silt and nutrients in fertilized flow ponds made this fish culture method most suitable.

Assessment of bottom sediment quality in Niterói harbor (Brazil, South America) through ecological indexes concerning nutrients and trace metals.

Bottom sediment quality from the Niterói harbor at Guanabara Bay (Rio de Janeiro, Brazil) was evaluated based on concentrations of organic phosphorus (OP) and inorganic phosphorus (IP) and bioavailability of trace metals through BCR fractionation analysis (Zn, Cu, Pb, Cr, Ni, Cd). The study area revealed elevated concentrations of fine sediments and organic matter (TOC: 2.26-7.31%). OP presented extremely elevated concentrations between 0.57 and 47.04 μmol/g, whereas IP reached a maximum concentration of 4.99 μmol/g. The anoxic bottom at the study area was confirmed by high TOC/OP values in most stations. Phosphorus enrichment index (PEI) varied between 0.07 and 2.57, pointing to ecological risk at some stations. Trace metals were mostly bonded to the bioavailable fractions (exchangeable, reducible, oxidizable), and decreasing order of mobility was Zn > Cu > Pb > Cr > Ni > Cd. The Risk Assessment Code (RAC) suggested a high risk of bioavailability for Zinc and a medium risk for the other metals. Overall, the Niterói harbor revealed poor sediment quality suggesting a strong anthropogenic pressure in the area.

Effect of the Level of Irradiance on Growth and Content of Photosynthetic Pigments of Canadian Elodea (Elodea canadensis) in Model System “Water-Bottom Sediments”

Bioassays based on aquatic plants are a convenient tool for studying the quality of bottom sediments. One of the stages in the development of a bioassay is the selection of optimal growth conditions for indicator plants in a model test system. Response of indicator physiological endpoints of Canadian waterweed (Elodea canadensis) to light flux density was investigated to determine optimal irradiance level in a “water – sediment” model system, proposed previously for contact bioassay of natural bulk bottom sediments. Based on the response of shoot and root growth (length and weight), and concentration and ratio of photosynthetic pigments (chl. a, chl. b, and carotenoids) of Elodea to the change of light flux density, no limitation or inhibition of growth and photosynthesis of Elodea was revealed at light flux density from 56 to 143 μmol quanta ∙ m-2 ∙ s-1. Hence, the level of irradiance within this range can be recommended for use in the experimental system proposed for bioassay of bulk bottom sediments using E. canadensis as an indicator

Investigation of the dependence of small rivers on the state of bottom sediments by mathematical methods

Emergency inflow of contaminants into river waters, construction of various hydraulic engineering structures can have an adverse impact on the river ecosystem. Water quality assessment is necessary for operative water resources management, development of engineering solutions for water streams rehabilitation. In this work, application of genetic algorithms for selection of significant indicators of bottom sediments quality for water quality indicators of small rivers in the Republic of Bashkortostan (Russia) has been tested. Selection of significant parameters for indicators of water quality of small rivers was conducted from input parameters: hydrochemical indicators of water quality, indicators of quality of bottom sediments.

Ecotoxicological characteristics and ecological risk assessment of trace elements in the bottom sediments of the Rożnów reservoir (Poland).

The bottom sediments in catchment areas behind dams play a significant role in water ecosystems. On the other hand, the structure of sediments makes them a natural geosorbent, in which pollutants introduced to the aquatic environment accumulate. The use of biotests is recognised as an important approach for the assessment of the quality of bottom sediments, as the chemical analysis of sediment samples alone does not provide evidence of the impact of contaminants on biota. The aim of the study was to apply the chemical and ecological indices to determine the potential risk posed by trace elements in the bottom sediments and to evaluate sediment toxicity using organisms belonging to two taxonomic groups, i.e., plants (Phytotoxkit) and crustaceans (Rapidtoxkit). The 46 sediment samples were taken from the Rożnów Dam Reservoir in Southern Poland. The mean concentration of the trace elements in the sediments was 5.22 mg As; 0.26 mg Cd; 63.23 mg Cr; 28.65 mg Cu; 37.11 mg Ni; 11.15 mg Pb; 69.69 mg Zn and 0.09 mg Hg ∙ kg-1 d.m. The mean probable effect concentration quotient (PECq) value among different sampling sites ranged between 0.04 and 0.33 suggested moderate potential toxicity to the biological communities in bottom sediments. The Ni was potentially the most toxic element for biota in the Rożnów Reservoir. The sensitivity of organisms formed the following order: Thamnocephalus platyurus >Lepidium sativum >Sinapis alba >Sorghum saccharatum. For the plants, the stimulating effect of bottom sediments on root growth was often indicated, while a toxic effect was demonstrated for T. platyurus in 80% of the samples. However, the correlation analysis and PCA results showed that trace elements that originated from similar sources were associated to the toxicity of sediments towards T. platyurus, while ecotoxicity for plants could not be explained by the content of trace elements in bottom sediments. T. platyurus is a good indicator for predicting the toxicity of bottom sediments from the Rożnów Reservoir. However, our study found that both chemical and ecotoxicological analyses are important for a comprehensive evaluation of the quality of bottom sediments.

Adapted methodology for comprehensive contamination assessment of bottom sediments on the content of various forms of heavy metals

As a result of long-term studies of bottom sediments of lakes, rivers, ponds and reservoirs of the Republic of Tatarstan, considerable factual material has been accumulated, which enabled the translation of quantitative estimates into qualitative characteristics. This necessitated a comprehensive assessment and generalization of the exceedance of the thresholds set for all metals, similarly to the specific combinatorial water pollution index (SCWPI). At the same time, the authors emphasize the features of such a comprehensive assessment of bottom sediments, and also suggest methods and algorithms for solving emerging problems. We use the method of frequency characteristics of data series of metal content (Cd, Pb, Co, Cu, Ni, Zn, Cr, Mn, Fe) in bottom sediments, score the relevant characteristics, generalize the point estimates and bring them to the appropriate classes of purity. As a result, a method for the integrated assessment of contamination of bottom sediments was developed and tested, which solves the problem of the integral assessment of the quality of bottom sediments in terms of a complex of pollutants using the example of heavy metals. The method is based on the approach of the SCWPI. Therefore, its results are comparable to combinatorial assessments of water quality, which will allow deriving a uniform assessment of the water body as a whole.

A METHOD FOR INTEGRATED ASSESSMENT OF SEDIMENT POLLUTION

The system for surface waters monitoring in the Russian Federation lacks criteria for assessing the quality of bottom sediments, which makes it difficult to identify and predict the development of processes affecting water quality, and to handle quite a number of tasks related to state control and surveillance of the use and protection of water bodies. As a result, information on the content of pollutants in sediments appears as a massive body of quantitative data whose practical application for the diagnosis of the ecological state of a water body is extremely difficult. The article analyzes the possibility of applying an algorithm for calculating the specific combinatorial water pollution index (SCWPI) for a comprehensive assessment of sediments pollution, for example, with heavy metals. The proposed system of formalized indicators uses frequency characteristics of data series on the content of total and labile forms of metals in sediments, scoring of these characteristics, synthesis of the scores and their conversion to pollution/cleanliness classes, similarly to the procedure in the guidelines RD 52.24.643–2002, but taking into account sediment-specific patterns and features of pollutant accumulation. The “specific combinatorial sediment pollution index” (SCSPI), the “quality class” and “pollution degree” of sediments are proposed as integral indicators. The scoring scale is formed with regard to the hazard class of heavy metals, as well as the actually observed ranges of their concentrations in sediments. The boundaries of the scale are the averaged frequency characteristics of the variation series of heavy metal content in sediment samples relative to their median. The contamination level of sediments is estimated by a relative characteristic calculated by comparing actual concentrations with the regional background. Corrections by means of special coefficients are introduced to the SCSPI calculation algorithm to account for the heterogeneity of the particle size composition of sediments. The scale for the quality of bottom sediments is divided into 9 classes and orders of pollution/cleanliness, ranging from “unpolluted” (class 1) to “extremely polluted” (class 5).The calculation of SCSPI for lakes of the Republic of Tatarstan with different levels of anthropogenic load showed good convergence of the results with similar approaches based on probabilistic statistics methods. An optimal result when comparing the pollution classes of water and sediments was obtained from determinations of active forms of metals in them. The estimates of gross metal contents in sediments are indicative of the threats and trends in the state of the water body for the future, if the load remains at the current level.

Environmental Soil, Water, and Sediment Quality of Dong Thang Landfill in Can Tho City, Vietnam

This study is a preliminary assessment of water, soil, and bottom sediment quality at and around Dong Thang landfill in Co Do district, Can Tho city, Vietnam. Four canal water samples, one leachate sample, and three soil samples from the surrounding rice fields, two bottom sediment samples from the canals, and one bottom sediment sample from the leachate pond were examined for this purpose. The results revealed that the leachate sample contained six heavy metals (Mn, Fe, Cu, Zn, Cr, and Ni) with high electrical conductivity (EC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), ammonia (NH4+-N), nitrate (NO3--N), and phosphate (PO43--P) (9922.7 μS cm-1, 832.00 mg L-1, 3,729.08 mg L-1, 743.75 mg L-1, 366.27 mg L-1, 6.03 mg L-1, and 0.22 mg L-1, respectively). Further, seven heavy metals (Zn, Cu, Mn, Cr, Ni, Pb, and Fe) were detected in the sediment of the leachate collection pond. COD, TSS, NH4+-N, Mn, and Fe concentrationsfor surface water exceeded the permissible level prescribed by the Vietnam national standard for surface water (QCVN 08-MT:2015/BTNMT). All heavy metals found in the leachate sediments were also detected in canal sediments and rice-field soil, thereby leading to the conclusion that pollutants disperse into the surrounding environment. Further, principal component analysis revealed that 91.3% of the variations in soil and sediment data could be explained by two primary components, PC1 and PC2. These components represent two sources of pollution, agricultural production and landfill activities, besides other pollution sources. The findings of this preliminary study show that water, soil, and bottom sediment in the area surrounding the landfill are contaminated with organic matter, nutrients, and heavy metals. Therefore, monitoring of the environment in the study area should be conducted to detect any pollutants, and alert local authorities and environmental managers.

Assessment of the Quality of Bottom Sediments in the Middle Reaches of the Yenisei River by Allium test

The harmful potential of bulk bottom sediments of the Yenisei River has been assessed by the Allium test. Sediment samples have been taken in ten sites on a plot of about 100 km in length in the middle reaches of the Yenisei River affected by urban activity of the city of Krasnoyarsk and industrial plants. The samples of sediments differ considerably in the content of potentially toxic substances (heavy metals, artificial radionuclides, and organic pollutants) and nutrients and in physical properties. We use the mean length of onion root as an indicator of general toxicity, the mitotic index as an indicator of cytotoxicity, and the percentage of anatelophase cells in the apical root meristem with abnormal chromosomes as an indicator of genotoxicity. Both the stimulation and inhibition of indicator endpoints are revealed in sediment samples of the Yenisei River relative to the control (artificial sediments). An increased genotoxicity is recorded in the sample of sediments contaminated by a mixture of organic and chemical toxicants. A significant positive correlation between the percentage of abnormal cells and the content of copper and petrochemicals in the samples is revealed. No extremely strong reactions of onion endpoints to the quality of sediment samples are revealed, which is probably related to relatively low contamination of the sediments studied. This is in agreement with the data of chemical analyses. Based on the testing results, we can conclude that the endpoints of the Allium test are sensitive enough to the quality of bottom sediments of the Yenisei River and can be used for their biotesting.

Assessment of the quality of bottom sediments of the middle reaches of the Yenisei River with Allium test

Assessment of the quality of bottom sediments of the middle reaches of the Yenisei River with Allium test

Change in Heavy Metals Concentrations in Sediments Deposited in Retention Tanks in a Stream after a Flood

Our paper presents the results of heavy metal (HM) (Zn, Cu, Pb, Cd) content in bottom sediments from retention tanks along Oliwa Stream in Gdansk, Poland, before a flood (BF) and after a flood (AF) 14-15 July 2016. The flood had a huge impact on the quality of bottom sediments and their displacement. The concentrations of HM differed significantly for research series conducted 3 months BF and 8 months AF. The concentration of Cu increased from 3.5 mg/kg to 88.8 mg/kg BF and from 12.1 mg/kg to 1,114.3 mg/kg AF, Zn from 27.4 mg/kg to 129.9 mg/kg BF; and 42.3 mg/kg to 244.8 mg/kg AF, Cd from 0.04 mg/kg to 0.47 mg/kg BF, and 0.08 mg/kg to 0.47 mg/kg AF. Also, the migration of some metals, mostly Cu to retention tanks located downstream, was observed, resulting from the washing away of sediments in the upper part of the stream. Since the stream inflows to the Gulf of Gdansk, urban flooding created a risk of migration of contaminants to the Baltic Sea.