Freshwater Pollution Research Articles

Toxicity assessment of TiO2-conjugated Carbon-based nanohybrid material on a freshwater bioindicator cladoceran, Daphnia magna.

The application of nanocomposite materials fabricated from titanium dioxide nanoparticles (TiO2 NPs) and different carbon (C) allotropes have gained popularity in water treatment applications due to their synergistic properties. Studies to date have focused on simple forms of nanomaterials (NMs), however, with the technology development, there is a dramatic increase in production and application of these complex NMs which could result in toxicological impacts on organisms when released into aquatic environments. This raises serious concerns about their safety and the need to ascertain their potential adverse effects on aquatic organisms. While conjugated TiO2 NPs/carbon-based nanohybrids (TiO2/C-NHs) may exhibit enhanced photocatalytic activity, there is no research in the scientific community regarding their toxicological effects on D. magna, which are indicators of freshwater pollution. In this study, two under-represented TiO2/C-NHs (i.e., TiO2- conjugated carbon nanofiber (CNF), and TiO2-conjugated multi-walled carbon nanotube (CNT)) were investigated for their toxic effects on D. magna, through a series of acute toxicity tests with a set of sublethal biochemical biomarkers of oxidative stress. The lethal toxicity and oxidative stress formation of TiO2/C-NHs over 48h revealed a concentration-dependant increase in D. magna mortality. The primary mechanism identified was the generation of ROS, which was in line with toxicity results. Light microscopy and CytoViva® images visualized D. magna interaction with the NPs, which accumulated and appeared as dark materials in the lines of the gut tract. The collective results indicate that TiO2/C-NHs have the potential to cause an effect on freshwater organisms when released into the environment. However, the relevance of TiO2/C-NHs effects needs further chronic toxicity studies since they show promise to be used in nano-bioremediation materials to treat wastewaters.

Recent advancements in hydrocarbon bioremediation and future challenges: a review.

Petrochemicals are important hydrocarbons, which are one of the major concerns when accidently escaped into the environment. On one hand, these cause soil and fresh water pollution on land due to their seepage and leakage from automobile and petrochemical industries. On the other hand, oil spills occur during the transport of crude oil or refined petroleum products in the oceans around the world.These hydrocarbon and petrochemical spills have not only posed a hazard to the environment and marine life, but also linked to numerous ailments like cancers and neural disorders. Therefore, it is very important to remove or degrade these pollutants before their hazardous effects deteriorate the environment. There are varieties of mechanical and chemical methods for removing hydrocarbons from polluted areas, but they are all ineffective and expensive. Bioremediation techniques provide an economical and eco-friendly mechanism for removing petrochemical and hydrocarbon residues from the affected sites. Bioremediation refers to the complete mineralization or transformation of complex organic pollutants into the simplest compounds by biological agents such as bacteria, fungi, etc. Many indigenous microbes present in nature are capable of detoxification of various hydrocarbons and their contaminants. This review presents an updated overview of recent advancements in various technologies used in the degradation and bioremediation of petroleum hydrocarbons, providing useful insights to manage such problems in an eco-friendly manner.

Acanthocephalan parasites reflect ecological status of freshwater ecosystem

Acanthocephalans' position in food webs, in close interaction with free-living species, could provide valuable information about freshwater ecosystem health through the viability of the parasites' host populations. We explored Pomphorhynchus laevis cystacanths' and adults' intensities of infection, and the prevalence of infected hosts respectively in their Gammarus pulex intermediate hosts and Squalius cephalus definitive hosts in a Mediterranean river. First, we analysed the relationship between P. laevis intensity of infection, its two hosts populations and the other acanthocephalan species found (Pomphorhynchus tereticollis and Polymorphus minutus). Second, we characterised the influence of bacteriological, physicochemical and biological water parameters on these acanthocephalans, and their intermediate and definitive hosts. This research highlights that P. laevis infection was closely related to their two preferential hosts population in the river. Moreover, P. laevis intensity of infection was positively correlated with organic pollution in the river but negatively correlated with biodiversity and with ecological indexes of quality. Pomphorhynchus laevis could thus benefit from moderate freshwater pollution, which promotes their tolerant intermediate and definitive hosts.

Role of Mine Tailings in the Spatio-Temporal Distribution of Phosphorus in River Water: The Case of B1 Dam Break in Brumadinho

Human actions in the drainage network of hydrographic basins interfere with the functioning of ecosystems, causing negative impacts on the environment. Among these impacts, mass loads with a high concentration of phosphorus (P) have a significant potential for point and diffuse pollution of freshwater. The objective of this work was to model P spatially in the Paraopeba River basin, namely in the main water course and 67 sub-basins, and temporally in the years of 2019, 2020, and 2021, after the rupture of B1 tailings dam of Vale, SA company in Brumadinho (Minas Gerais Brazil). The distribution of total phosphorus concentrations (Pt) in relation to environmental attributes (terrain slope, soil class, and land use) and stream flow was assessed with the help of SWAT, the well-known Soil and Water Assessment Tool, coupled with box-plot and cluster analyses. The Pt were obtained from 33 sampling points monitored on a weekly basis. Mean values varied from 0.02 to 1.1 mg/L and maximum from 0.2 to 15.9 mg/L across the basin. The modeling results exposed an impact on the quality of Paraopeba River water in a stretch extending 8.8–155.3 km from the B1 dam, related with the rupture. In this sector, if the contribution from the rupture could be isolated from the other sources, the average Pt would be 0.1 mg/L. The highest Pt (15.9 mg/L) was directly proportional to the urban area of a sub-basin intersecting the limits of Betim town and Belo Horizonte Metropolitan Region. In general, urban sprawl as well as forest-agriculture and forest-mining conversions showed a close relationship with increased Pt, as did sub-basins with a predominance of argisols and an accentuated slope (>20%). There were various moments presenting Pt above legal thresholds (e.g., >0.15 mg/L), mainly in the rainy season.

Nanofiltration membranes fabricated through ultra-thin α-Co(OH)2 nanosheets with high chlorine resistance and long-term stability for efficient dye removal

At present, freshwater resources are scarce, and printing and dyeing wastewater are the main freshwater pollution sources. To purify dye wastewater, nanofiltration membrane technology was developed. This study developed a new nanofiltration membrane by mixing an ultra-thin α-Co(OH)2 nanosheets with sodium alginate (SA) and papermaking by-products calcium lignosulfonate (CaLS). X-ray diffraction (XRD), Fourier Infrared Spectroscopy (FITR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Contact angle (CA) were used to analyze ultra-thin α-Co(OH)2 nanosheets and α-Co(OH)2@CaLS/SA membrane, confirming the successful synthesis and sheet morphology of the α-Co(OH)2 nanosheets, and finding the hydrophilicity increases of the α-Co(OH)2@CaLS/SA membrane and its morphology change. Dye separation experiments showed that the α-Co(OH)2@CaLS/SA membrane has a good separation effect on Rose Bengal sodium salt, Coomassie brilliant blue and Congo red dyes, with a retention rate is above 99%. Moreover, the membrane showed high flux for Rose Bengal sodium salt 48.5 L m−2 h−1, Coomassie Brilliant Blue 60.4 L m−2 h−1, Congo Red 74.8 L m−2 h−1. In addition, the α-Co(OH)2@CaLS/SA membrane has superior chlorine resistance and long-term operation stability, which provides advantages in industrial applications.

Microplastics in intertidal water of South Australia and the mussel Mytilus spp.; the contrasting effect of population on concentration

Microplastics, plastic particles <5 mm in size, are of global concern as human-caused pollutants in marine and fresh waters, and yet little is known of their distribution, behaviour and ecological impact in the intertidal environment of South Australia. This study confirms for the first time, the presence of microplastic in the South Australian intertidal ecosystem by quantifying the abundance of particles in intertidal water and in the keystone species, the blue mussel, Mytilus spp., an important fisheries species, at ten and six locations respectively, along the South Australian coastline. For a remote region known for its pristine environment, microplastic concentration in intertidal water was found to be low to moderate (mean = 8.21 particles l−1 ± 4.91) relative to global levels and microplastic abundance in mussels (mean = 3.58 ± 8.18 particles individual−1) was within the range also reported globally. Microplastic particles were ubiquitous across sites and bioavailable by size in water (mean = 906.36 μm) and in mussel (mean = 983.29 μm) raising concerns for the health of South Australia's unique coastal ecosystems and for the human food chain. Furthermore, a positive correlation was found between human coastal population size and microplastic concentration in intertidal water, irrespective of influences from industry - tourism, fishing and shipping ports. FTIR analysis determined plastic type to include polyamide (PA), polyethylene (PE), polypropylene (PP), acrylic resin, polyethyleneterephthalate (PET) and cellulose, suggesting synthetic and semi-synthetic particles from single-use, short-life cycle products, fabrics, ropes and cordage. Our findings shed light on the urgent need to establish the local sources of microplastic pollution in order to assist the community, industry and government to reduce the impact of microplastic on the fragile marine systems within South Australian intertidal waters and on the organisms associated with the human food chain.

Trophic transfer of microplastics in a model freshwater microcosm; lack of a consumer avoidance response

Microplastics are considered freshwater pollutants of emerging concern. Although microplastics have been identified in a range of taxa, only a limited number of studies have focussed on the trophic transfer of microplastics. The duckweed Lemna minor can act as a microplastic vector in a model freshwater food chain. Here we show for the first time scanning electron microscopy images of 1 μm polystyrene (PS) and 10–45 μm polyethylene (PE) microplastics adsorbed on L. minor surfaces. A feeding test and a novel feeding-choice test were designed to investigate microplastic transfer from freshwater plants to invertebrates. Both tests show that the freshwater amphipod Gammarus duebeni feeds on plant biomass irrespective of the presence of microplastics, indicating lack of avoidance of microplastics. A number of G. duebeni that were fed L. minor with adsorbed PE microplastics had accumulated microplastics in their digestive tracts at the end of the tests. Fragmentation of microplastics transferred via plant feed and using low concentrations was noted for the first time. PE fragments, including particles in the nanosized range, were observed in G. duebeni digestive tracts. Yet, there was no apparent acute negative effect on G. duebeni weight or survival. These findings demonstrate microplastic trophic transfer and fragmentation in a freshwater organism. The finding that novel nanoplastics are found in the gut does show that biological processes are co-determinants of the fate of plastics in the environment and emphasise the importance of nanoplastic impact studies.

Antioxidant response to heavy metal pollution of Regi Lagni freshwater in Conocephalum conicum L. (Dum.)

Conocephalum conicum L. is a cosmopolitan liverwort species able to respond to local environmental pollution by changing its biological features. In the present study, we assessed the different biological responses in C. conicum to heavy metal contamination of Regi Lagni channels, a highly polluted freshwater body. As for the in field experiment, we set up moss bags containing collected samples of the local wild growing C. conicum, from the upstream site (non-polluted area), and we exposed them in the three selected sites characterized by different and extreme conditions of heavy metal pollution. In addition, to better understand the contribution of heavy metals to the alterations and response of the liverwort, we performed in vitro tests, using the same concentration of heavy metals measured in the sites at the moment of the exposition. In both experimental settings, bioaccumulation, ultrastructural damage, reactive oxygen species production and localization, antioxidant enzymes activity (superoxide dismutase, catalase and glutathione S-transferases), glutathione (reduced and oxidized) levels, localization of compounds presenting thiol groups and phenolic content were investigated. The results showed that the samples from different sites and conditions (for in vitro tests) showed significant differences. In particular, the ultrastructural alterations show a trend correlated to the different exposure situations; ROS contents, glutathione, antioxidant enzyme activities, and phenolic contents were increased showing an enhancement of the antioxidant defense both by the enzymatic way and by using the synthesis of antioxidant phenolic compounds. This study confirms the ability of C. conicum to respond to heavy metal pollution and the responses studied are, at least partially, correlated to the presence of heavy metals. All the responses considered respond consistently with the pollution trend and they can be proposed as pollution biomarkers. Therefore, we suggest the use of C. conicum to identify local hot spots of pollution in further investigation.

Separation and identification of nanoplastics in tap water.

Microplastics pollution in freshwater has attracted global attentions, but when microplastics are broken into nanoplastics, they may present higher toxicity mainly due to their greater potential to cross biological membranes. So far almost no work has been done on the separation and identification of nanoplastics in tap water. Herein we removed large particles from tap water by 0.45μm filter and then sequentially screened nanoparticles in filtrate by Anopore with pore size of 200, 100, and 20nm, the most frequent particle sizes of which concentrate at 255nm, 148nm, and 58nm, respectively. Based on characterization of FTIR, AFM-IR and Pyr-GC/MS, the polymers were identified to be polyolefins, polystyrene, polyvinyl chloride, polyamide, and some plastic additives. The abundance of nanoplastics with the most frequent particle sizes in range of 58-255nm was 1.67-2.08μg/L in tap water. This work provides a feasible method for separation and identification of nanoplastics in tap water, and manifests the existence of nanoplastics, which poses a potential threat to the health of residents.

Agrobiodiversity as Necessary Standard for the Design and Management of Sustainable Farming Systems

Agriculture constitutes the major planetary force, which over the course of the past century has been changing forever the connotations of terrestrial ecosystems, due to its dependence on resources and impacts (e.g.: global climate change, biodiversity loss, pollution, and eutrophication of fresh and coastal waters). The purpose of this work aimed at demonstrating the compelling need to design and manage modern farms in a way that these may conserve, and even foster biodiversity because its restoration offers resilience, longevity, and productivity to 21st century farms. Therefore, special emphasis in this work was given to the management of agricultural soils and agroforestry. These approaches enhance biological diversity, while strengthening the health of plants, animals, and human communities thus, contributing to the health of planet Earth. Agroecology is the science, practice and social movement that effectively, can assist with a conversion of farming systems toward sustainability and a restoration of agrobiodiversity.

Microbial pollution in inland recreational freshwaters of Quetta, Pakistan: an initial report.

Parasitic contamination of surface waters, especially recreational waters, is a serious problem for under-developed nations like Pakistan, where numerous outbreaks of parasitic diseases are reported each year. In the current study, parasitic presence in two surface waters (Hanna Lake and Wali-Tangi Dam) of Quetta was monitored quarterly for 1 year. The methodology involved the pre-concentration of the water samples and the subsequent preparation for the microscopic search of parasites. Physico-chemical and bacteriological variables were also studied. Wet staining, modified Trichrome staining, and modified acid-fast staining methods were used to identify various parasitic forms (cysts, oocysts, eggs, trophozoites). Collectively 11 parasitic elements (10 in Lake and 8 in Dam) belonging to 10 species were recorded, many of which are potential human pathogens. The species identified include Trichomonas sp., Isospora sp., Balantidium coli, Cryptosporidium sp., Entamoeba spp., amoebas, Microsporidium sp., Endolimax nana, Ascaris lumbricoides, and Giardia spp. Parasitic contamination remained persistent in both locations throughout the year independent of physico-chemical parameters (temperature, EC, pH, turbidity, and DO) and bacterial concentration of water. Reliance on bacterial presence for monitoring of recreational waters can be a risk for tourists. Entamoeba spp. and A. lumbricoides may be used for surface water monitoring in these waters.

Predicting Optimum Dilution Factors for BOD Sampling and Desired Dissolved Oxygen for Controlling Organic Contamination in Various Wastewaters

High biochemical oxygen demand (BOD) concentrations in water minimize oxygen availability, damage ecosystem biodiversity, impair water quality, and spoil freshwater. The increased level of BOD is an indication of severe organic pollution of freshwater. Thus, this study aims to establish empirical correlations between the 5-day biochemical oxygen demand (BOD5) and organic decomposition time to control organic pollution in various wastewater effluents. Ultimate biochemical oxygen demand (UBOD) and minimum and average BODt data sets along with their reaction rates were collected from earlier sampling analyses in the plants used for industrial, domestic (sanitary), and storm (surface) wastewater treatment. Average BOD5/COD ratios were then utilized to calculate existing 5-day dissolved oxygen (DO5) concentration for the estimation of experimental dilution factors (dfs) as a good start in sampling analysis to reach an optimum DO5 concentration. Moreover, the relationships between average BOD5 vs. COD, and BOD5 vs. DO5, were obtained based on the literature with 60–70% oxygen consumption rates required for organic decomposition. Results showed that such BOD5 relationships with time (power equations) or with COD (linear correlations) are helpful for wastewater engineers to generate valuable and accurate results for quality control, without the need to conduct laboratory experiments. The proposed regression equations would facilitate effluent quality assessment, allowing selection of optimal processes to control microbiological contamination or organic constituents in wastewaters.

Improving the proteome coverage of Daphnia magna - implications for future ecotoxicoproteomics studies.

Aquatic pollution is an increasing problem and requires extensive research efforts to understand associated consequences and to find suitable solutions. The crustacean Daphnia is a keystone species in lacustrine ecosystems by connecting primary producers with higher trophic levels. Therefore, Daphnia is perfectly suitable to investigate biological effects of freshwater pollution and is frequently used as an important model organism in ecotoxicology. The field of ecotoxicoproteomics has become increasingly prevalent, as proteins are important for an organism's physiology and respond rapidly to changing environmental conditions. However, one obstacle in proteome analysis of Daphnia is highly abundant proteins like vitellogenin, decreasing the analytical depth of proteome analysis. To improve proteome coverage in Daphnia, we established an easy-to-use procedure based on the LC-MS/MS of whole daphnids and the dissected Daphnia gut, which is the main tissue getting in contact with soluble and particulate pollutants, separately. Using a comprehensive spectral library, generated by gas-phase fractionation and a data-independent acquisition method, we identified 4621 and 5233 protein groups at high confidence (false discovery rate<0.01) in Daphnia and Daphnia gut samples, respectively. By combining both datasets, a proteome coverage of 6027 proteins was achieved, demonstrating the effectiveness of our approach.

Pollutant co-attenuation via in-stream interactions between mine drainage and municipal wastewater

Municipal wastewater (MWW) and mine drainage (MD) are common co-occurring sources of freshwater pollution in mining regions. The physicochemical interactions that occur after mixing MWW and MD in a waterway may improve downstream water quality of an impaired reach by reducing downstream concentrations of nutrients and metals (i.e., “co-attenuation”). A first-order stream (Bradley Run in central Pennsylvania), with coal MD and secondarily treated MWW entering the stream in the same location, was systematically monitored to determine in-stream water-quality dynamics. Monitored constituents included pH, nutrients (i.e., phosphorus and nitrogen), and metals (e.g., iron, aluminum, manganese). Mixing of the MWW, MD, and upstream water decreased concentrations of phosphate, aluminum, and iron by 94%, 91%, and 98%, respectively, relative to conservative mixtures at the 1400-m-downstream site. The pollutant co-attenuation resulted in water quality equivalent to that upstream of the pollutant sources and improved the phosphorus-based trophic status of the stream. Geochemical models indicate the primary mechanisms for P attenuation in the studied stream were precipitation as variscite (AlPO4:2H2O) or amorphous AlPO4 plus adsorption to hydrous ferric oxide, despite a much greater abundance of hydrous aluminum oxide. The results presented in this study suggest that in-stream mixing of MD with untreated or secondarily treated MWW may be an important, overlooked factor affecting downstream transport of common pollutants in mining regions. Decreased metals loading and increased pH resulting from natural attenuation and remediation of MD could affect the potential for retention of phosphate by stream sediment and could lead to the release of nutrients from legacy accumulations, highlighting the potential need to address high-nutrient discharges (e.g., improved MWW treatment) in concert with MD remediation.

Water Law in Circular Economy: Ultra Vires Actions in Environmental Sector, or when Union Ambition Far Exceed its Abilities

Water management has an important role to play in the circular economy transition, through the water treatment and reuse. Its optimal and coherent regulation is also of vital common interest, since water knows no borders or lines artificially set out by the States and the dramatic overconsumption and pollution of freshwater are threatening irreparable damage to the world's ecosystems. However, States are reluctant to common regulations, which would have important economic impacts. International and regional organizations face with the fundamental principle of permanent sovereignty of States over natural resources. By analysing the European environmental competence, this study examines the role of Union water law in green economic transition. By investigating the interdependent relationships between the several elements of the water management, the essay suggests that territory use and economic town and country planning would be drawn into the scope of Treaties because of the integrated nature of water services. The case of water reuse illustrates limits and perspectives of the European objective to promote rational utilization of natural resources and combat climate change, introducing the idea according to which freshwater is a European res communis on which the sovereign right of European Union Member States over their own natural resources could be lawfully limited.

Assessing Occurrence and Biological Consequences of Contaminants of Emerging Concern on Oceanic Islands

Freshwater streams on oceanic islands serve critical ecological and economic functions. However, these are underrepresented in assessments of pollution from contaminants of emerging concern (CEC). Furthermore, freshwater streams and their endemic fauna often have characteristics that are distinct from those of continental streams and model species, calling extrapolations from studies of such systems into question for island streams. In the current study, we assessed the presence of CEC across three sampling events and five freshwater streams on the Island of Hawai’i. We also exposed juveniles of the native fish species Sicyopterus stimpsoni to a mixture of commonly co-occurring CEC for 96 h in static renewal experiments, testing for impacts of CEC in two ecologically relevant assays of functional performance. CEC from multiple sources were ubiquitous in Hawaiian streams, including human-use pharmaceuticals, agricultural herbicides, and industrial runoff. Concentrations of CEC were comparable to published studies from continental streams, exceeding total concentrations of 1000 ng/L for the eight quantified CEC in four samples, and approaching 2500 ng/L in one sample. Effects on exposed fish were subtle and limited to treatments with higher CEC concentrations but indicated potential impacts of CEC on locomotor performance. These results indicate that Hawaiian streams follow a global trend of widespread freshwater pollution by CEC that are accompanied by subtle effects on native fish species and highlight the need for the inclusion of endemic species and ecologically relevant assays when assessing the effects of contaminants in island habitats.

Anthropogenic Drivers of Variation in Concentrations of Perfluoroalkyl Substances in Otters (Lutra lutra) from England and Wales.

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous environmental contaminants that have been linked to adverse health effects in wildlife and humans. Here, we report the presence of PFASs in Eurasian otters (Lutra lutra) in England and Wales and their association with anthropogenic sources. The following 15 compounds were analyzed: 10 perfluoroalkyl carboxylic acids (PFCAs), 4 perfluoroalkyl sulfonic acids (PFSAs), and perfluorooctane sulfonamide, in livers of 50 otters which died between 2007 and 2009. PFASs were detected in all otters analyzed, with 12/15 compounds detected in ≥80% of otters. Perfluorooctane sulfonate (PFOS) accounted for 75% of the ΣPFAS profile, with a maximum concentration of 6800 μg/kg wet weight (ww). Long-chain (≥C8) PFCAs accounted for 99.9% of the ΣPFCA profile, with perfluorodecanoic acid and perfluorononanoic acid having the highest maxima (369 μg/kg ww and 170 μg/kg ww, respectively). Perfluorooctanoic acid (PFOA) concentrations were negatively associated with the distance from a factory that used PFOA in polytetrafluoroethylene manufacture. Most PFAS concentrations in otters were positively associated with load entering wastewater treatment works (WWTW) and with arable land, suggesting that WWTW effluent and sewage sludge-amended soils are significant pathways of PFASs into freshwaters. Our results reveal the widespread pollution of British freshwaters with PFASs and demonstrate the utility of otters as effective sentinels for spatial variation in PFAS concentrations.

СУЧАСНІ АСПЕКТИ АУДИТУ ЕФЕКТИВНОСТІ ДЕРЖАВНИХ ЗАКУПІВЕЛЬ

The article presents an overview of current aspects of public procurement audit. It is proved that today the scientists have mostly practical recommendations for such an audit and monitoring. It is established that there are no significant, thorough theoretical and methodological developments of scientists on the audit of public procurement in a circular economy, sustainable development. It is proved that special attention at the current stage of formation of the audit of public procurement should be paid to such an area as monitoring their "sustainability". The article identifies economic, environmental and social criteria in the audit of public procurement. Economic factors affect the state of the markets on which trade depends now and in the future. Environmental factors affect the natural systems on which life depends now and in the future. Social factors affect the social systems on which the community depends now and in the future. Among the economic criteria are: fair agreements, innovative research, investment, open competition, open information, use of different suppliers, use of HUB zones, use of local suppliers, conflicts of interest, zoning, dumping, exclusive agreement, seller's conspiracy, buyer's conspiracy, abuse patent, pricing, product typing, refusal of the agreement, corruption (bribery, extortion). Among the ecological criteria are the following: biodiversity conservation, climate adaptation, resource optimization, soil fertility concern, acidification, desertification, eutrophication (waterlogging), fresh water pollution, greenhouse gas emissions, environmental depletion, human health impact, land use change, marine pollution, pollution layer, radiation pollution, depletion of resources, smog, waste. To the social criteria it was included: anti-discrimination, community involvement, equal opportunities, employee involvement, equal pay, fair agreement, freedom of association, grievance and redress processes, human rights, indigenous rights, labour protection and safety, the right to bargain collectively, education and training, workers' rights, child labour, forced labour, trafficking in human beings, choice of suppliers. It is substantiated that among the criteria of sustainability (economic, environmental and social) the red ribbon is the assessment of possible abuses, corruption, bribery, dishonesty of the administration. So, also it has been investigated the relationship between administrative dishonesty and leadership style and reporting distortions.

Accumulation of microplastics in the bivalve mollusc Unio tumidus under experimental and field exposures

Background. An increased production and widespread use of plastics have made microplastic (MP) pollution a serious environmental problem. Most of MP found in the marine environment comes from rivers, however, the freshwater pollution by MP is less studied. Filter-feeding organisms, like bivalve molluscs, are the primary target orga­nisms for MP. Nevertheless, the studies of MP accumulation in the bivalves mainly focus on the marine species and depend on expensive equipment. The goal of this study was to detect the presence of MP in the body of freshwater bivalve mollusc Unio tumidus from a typical field site in Western Ukraine and under laboratory sub-chronic exposure to microplastic at a typical concentration for freshwater. Materials and Methods. For the study, we exposed molluscs to waterborne MP (0.1–0.5 mm) in the concentration of 1.0 mg L-1 corresponding to ~850 items L-1 for 14 days and analysed the concentration of MP in the soft tissues and water every two days. The molluscs and water from the field site, confirmed as polluted one, were also analysed. To estimate the number of MP particles, we used a modified method based on the cleavage of biological materials with potassium hydroxide and hydrogen peroxide and microscopic analysis of MP after the staining with fluorescent Nile Red dye. Results. The MP concentration in the soft tissues of the specimens from the refe­rence site was 9.5 items per soft body and demonstrated a bell-shaped response curve throughout the 14-days exposure with maximum of 327.0 items per body on the 10th day and a negative correlation with the concentration of MP in the experimental tank that changed within the range of 590–790 items L-1. The level of MP in the field specimens from the polluted area was 76.5 items per body, and in the water, it was about 103 items L-1. The maximum MP abundance factor, calculated as CFi = Ci/C0 (utilising the value 9.5 as C0), was 83.18 and 8.05 for 10 days of exposure and field specimens, correspondingly. Conclusion. These data indicate the high accumulative ability of U. tumidus towards microplastics and draw attention to the utilizing of this species for the biomonitoring of microplastics pollution and depuration of surface waters from it.

Effects of Aluminium Contamination on the Nervous System of Freshwater Aquatic Vertebrates: A Review.

Aluminium (Al) is the most common natural metallic element in the Earth’s crust. It is released into the environment through natural processes and human activities and accumulates in aquatic environments. This review compiles scientific data on the neurotoxicity of aluminium contamination on the nervous system of aquatic organisms. More precisely, it helps identify biomarkers of aluminium exposure for aquatic environment biomonitoring in freshwater aquatic vertebrates. Al is neurotoxic and accumulates in the nervous system of aquatic vertebrates, which is why it could be responsible for oxidative stress. In addition, it activates and inhibits antioxidant enzymes and leads to changes in acetylcholinesterase activity, neurotransmitter levels, and in the expression of several neural genes and nerve cell components. It also causes histological changes in nerve tissue, modifications of organism behaviour, and cognitive deficit. However, impacts of aluminium exposure on the early stages of aquatic vertebrate development are poorly described. Lastly, this review also poses the question of how accurate aquatic vertebrates (fishes and amphibians) could be used as model organisms to complement biological data relating to the developmental aspect. This “challenge” is very relevant since freshwater pollution with heavy metals has increased in the last few decades.