Search Results (763)

The species sensitivity distribution (SSD) analysis for aquatic ecosystems has been increasingly used in risk assessment. However, existing analyses of the impact of trace metals in lake sediments on aquatic organisms often neglect the spatiotemporal variability of trace metal release. This oversight can result in ecological risk assessments that lack specificity. To address this gap, we collected 32 core sediment samples from Lake Chaohu to systematically investigate the ecological toxicological risks posed by the release of eight trace metal indicators into the overlying water column under four hydrological scenarios throughout the year. Results indicated that only Cu, Pb, and Zn exhibit persistent toxicological risks. The comprehensive ecological toxicological risk of sediment trace metals showed spatial differences, increasing from the western region to the eastern region, i.e., western region < central region < eastern region. Seasonally, the risk levels are ordered as follows: May < September < November to April of the following year < June to August. The eastern region in summer (June to August) was identified as the high-risk area and period for trace metal pollution in sediments. Based on these conclusions, it is recommended to implement pollution control and environmental monitoring measures in the eastern region during the summer to effectively control the pollution and ecological risks of trace metals. Full article

Biological wastewater treatment plants could serve as an important alternative to renewable biological nitrogen mines, which are locally available and have a low carbon footprint. Recent progress in Fenton processes has revealed their potential use for sludge treatment to decrease organic contamination and pathogens. The aim of this study was to determine the optimal concentrations of metal catalyst Fe(II) and hydrogen peroxide H₂O₂ for activated sludge (AS) disinfection using the Fenton process at near-neutral pH, alone and in combination with thermal treatment and UV radiation. The efficiency of the 48 h treatment was evaluated by log reduction, fluorescein diacetate (FDA) hydrolysis activity, concentration of pharmaceuticals, changes in antimicrobial resistance, and ecotoxicity. Using the desirability function approach, a combination of 239 mM H₂O₂ and 8.6 mM Fe(II) was found to be optimal in frames of the chosen concentrations of reagents. The FDA hydrolysis activity correlated with log reduction at 287 mM H₂O₂ and different Fe(II) concentrations. Sludge treatment resulted in the removal of ciprofloxacin by 65.5%. The sets with the highest log reduction, i.e., additionally treated by heating and UV, were accompanied by increasing ecotoxic effects on crustaceans, Thamnocephalus platyurus. The Fenton process shows prospective ways on sludge stabilization for its application as a fertilizer. Full article

Life cycle assessment (LCA) has been used to evaluate wastewater treatment technologies, processes, and scenarios. The outcomes of LCA are affected by various uncertainties, including those from input data and those from the LCA model set-up (i.e., structural uncertainty). The impacts of structural uncertainty have not received adequate attention in research. The objective of this study was to quantify how the subjective choices embedded in the LCA model set-up affect the LCA outcomes of three wastewater sludge treatment processes. The subjective choices were based on LCA’s cultural theory that considers the three different human perspectives: egalitarian, hierarchist, and individualist. The three processes are multiple hearth incineration (MHI), fluid bed incineration (FBI), and anaerobic digestion (AD) for wastewater sludge treatment. This study revealed that for MHI, lower impacts are in the categories of human toxicity and marine ecotoxicity under the individualist perspective when compared to the other two perspectives, but higher impacts are in the categories of terrestrial acidification, terrestrial ecotoxicity, fresh water ecotoxicity, and marine ecotoxicity under the egalitarian perspective. Among the three subjective perspectives and the three studied wastewater sludge treatment processes, AD has the lowest and MHI has the highest environmental impacts. The results from this study revealed that the differences from subjective choices created large differences in LCA outcomes in climate change, human toxicity, ionizing radiation, terrestrial acidification, terrestrial ecotoxicity, and marine ecotoxicity. Findings from this study can benefit stake holders to understand the impacts of subjective choices and the limitation of LCA outcomes for making informed and sound decisions. Full article

Composite materials based on diatomite (DT) with the addition of biochar (BC), dolomite (DL), and bentonite (BN) were developed. The effect of chemical modification on the chemical structure of the resulting composites was investigated, and their influence on heavy metal immobilization and the ecotoxicity of post-flotation sediments was evaluated. It was demonstrated that the chemical modifications resulted in notable alterations to the chemical properties of the composites compared to pure DT and mixtures of DT with BC, DL, and BN. An increase in negative charge was observed in all variants. The addition of BC introduced valuable chemically and thermally resistant organic components into the composite. Among the chemical modifications, composites with the addition of perlite exhibited the lowest values of negative surface charge, which was attributed to the dissolution and transformation of silicon compounds and traces of kaolinite during their initial etching with sodium hydroxide. The materials exhibited varying efficiencies in metal immobilization, which is determined by both the type of DT additive and the type of chemical modification applied. The greatest efficacy in reducing the mobility of heavy metals was observed in the PFS with the addition of DT and BC without modification and with the addition of DT and BC after the modification of H₂SO₄ and H₂O₂: Cd 8% and 6%; Cr 71% and 69%; Cu 12% and 14%; Ni 10% and Zn 15%; and 4% and 5%. In addition, for Zn and Pb, good efficacy in reducing the content of mobile forms of these elements was observed for DT and DL without appropriate modification: 4% and 20%. The highest reduction in ecotoxicity was observed in the PFS with the addition of DT and BC, followed by BN and DL, which demonstrated comparable efficacy to materials with DT and BN. Full article

Straw return and plastic film mulching are two critical management measures that not only maintain high and stable crop yields, but also have a significant impact on the ecological environment. However, there is still a lack of research on the comprehensive effects of straw return and different film mulching treatments on the ecological environment. Thus, a 2-year field experiment was conducted and six treatments, which included two main treatments, namely straw return (SR) and non-straw return (NR), and three sub-treatments, namely no film mulching (CK), plastic film mulching (PM) and fully biodegradable film mulching (BM), were applied in a garlic cropping system. Based on the life cycle assessment method, six endpoint damage categories, resource consumption, global warming potential, environmental acidification, eutrophication, human health, and ecotoxicity, were assessed. Furthermore, we also evaluated the costs and economic benefits of the six treatments and optimized the treatment of used mulch and straw off-farm. The results indicated that the environmental impacts of the six endpoint damages in the garlic cropping system were ranked as ecotoxicity, eutrophication, environmental acidification, global warming potential, human health, and resource consumption. The SR-BM treatment had the lowest life cycle environmental impact composite index at 27.68 per unit area, followed by SR-PM at 27.75. All six endpoint damage categories for the PM and BM treatments were lower than the CK treatment per t of yield, with the SR-BM treatment being the most economically efficient, yielding at 3691.03 CNY·t⁻¹ and exceeding that of the SR-CK treatment by 7.26%. Fertilizer inputs were the primary contributor to resource consumption, global warming potential, environmental acidification, eutrophication, and ecotoxicity, accounting for about 72.80% of these five environmental impacts. Crop protection significantly affected human health, and garlic mulching helped minimize pesticide use, thereby reducing potential health impacts. Compared to straw incineration and waste mulch power generation, straw power generation and waste mulch recycling granulation offered positive environmental benefits and were more effective offset strategies. In conclusion, straw return with biodegradable mulch is a synergistic cultivation measure that offers both environmental and economic benefits. For straw return with plastic film mulch, environmental impacts can be reduced by waste mulch recycling granulation. Full article

The pervasiveness of microplastics (MPs) in terrestrial and aquatic ecosystems has become a significant environmental concern in recent years. Because of their slow rate of disposal, MPs are ubiquitous in the environment. As a consequence of indiscriminate use, landfill deposits, and inadequate recycling methods, MP production and environmental accumulation are expanding at an alarming rate, resulting in a range of economic, social, and environmental repercussions. Aquatic organisms, including fish and various crustaceans, consume MPs, which are ultimately consumed by humans at the tertiary level of the food chain. Blocking the digestive tracts, disrupting digestive behavior, and ultimately reducing the reproductive growth of entire living organisms are all consequences of this phenomenon. In order to assess the potential environmental impacts and the resources required for the life of a plastic product, the importance of life cycle assessment (LCA) and circularity is underscored. MPs-related ecosystem degradation has not yet been adequately incorporated into LCA, a tool for evaluating the environmental performance of product and technology life cycles. It is a technique that is designed to quantify the environmental effects of a product from its inception to its demise, and it is frequently employed in the context of plastics. The control of MPs is necessary due to the growing concern that MPs pose as a newly emergent potential threat. This is due to the consequences of their use. This paper provides a critical analysis of the formation, distribution, and methods used for detecting MPs. The effects of MPs on ecosystems and human health are also discussed, which posed a great challenge to conduct an LCA related to MPs. The socio-economic impacts of MPs and their management are also discussed. This paper paves the way for understanding the ecotoxicological impacts of the emerging MP threat and their associated issues to LCA and limits the environmental impact of plastic. Full article

The Sri Lankan transport sector still depends predominantly on petroleum fuels, mainly diesel and gasoline. Gasoline holds the second highest market share, and with the increasing number of gasoline-fueled vehicles, its proportion in the transport fuel mix is continuously expanding. The main objective of this study is to assess the ecological burden associated with the gasoline supply chain in Sri Lanka by conducting a life cycle assessment from a ‘well-to-tank’ perspective. In the scenario analysis, the environmental impacts of four potential gasoline distribution scenarios were assessed and compared with the existing distribution model. According to the results, the refining process was predominant, contributing more than 50% to climate change, terrestrial acidification, marine and freshwater eutrophication, human toxicity, and terrestrial and marine ecotoxicities. Meanwhile, crude oil extraction dominates in its contribution to ozone depletion, photochemical oxidant formation, freshwater ecotoxicity, and fossil depletion. The results of the scenario analysis show a remarkable reduction in the environmental load when rail transport is solely used to transfer gasoline from bulk terminals to regional depots. The reduction is over 65% in most impact categories compared to the existing distribution method, which involves a combination of both road and rail transport. This study identifies the key areas that need to be further analyzed to lower the environmental impacts while also establishing a foundation for conducting comparative environmental assessments of alternative fuel options in the Sri Lankan context. Full article

Lincomycin belongs to the antibiotics commonly used in veterinary medicine. Its residues are easily spread in the environment because of its physicochemical properties, including resistance to biodegradation and good solubility in water. One of the effective methods for the removal of lincomycin from wastewater is the photocatalytic process, but it is not widely used due to the price of photocatalysts. The aim of this work was to compare the photocatalytic efficiency and the mechanism of lincomycin degradation initiated by UVa radiation in the presence of TiO₂-P25 and ZnO, as well as in the presence of industrial pigments commonly used in construction and containing TiO₂. Lincomycin was found to undergo efficient photocatalytic degradation in the presence of a commercial TiO₂-P25 photocatalyst, industrial pigments containing only anatase, and in the presence of ZnO. On the contrary, industrial pigments containing only rutile or a mixture of rutile and anatase practically did not show any photocatalytic activity. The composition of the solutions after the degradation of lincomycin in the presence of TiO₂-P25 and ZnO differed significantly. Most of the identified organic degradation products contained conserved pharmacophores, and some of them could have been highly ecotoxic. Full article

This review provides a comprehensive Life Cycle Assessment (LCA) of a cosmetic cream to assess the environmental impacts throughout its entire life cycle, from raw material extraction to disposal, using the methodology according to international standards. The LCA was performed using the OpenLCA 2.0.1 software, with data from the Ecoinvent 3.8 database and relevant literature. The assessment focused on multiple impact categories, including climate change, acidification, eutrophication (freshwater, marine and terrestrial), ecotoxicity (freshwater), human toxicity (cancer and non-cancer), ionizing radiation, land use, ozone depletion, photochemical ozone formation, resource use (fossils, minerals and metals), and water use. The LCA of a cosmetic cream containing gold nanoparticles revealed significant environmental impacts across critical categories. The total climate change potential was 2596.95 kg CO₂ eq., driven primarily by nanoparticle synthesis (60.7%) and electricity use (31.9%). Eutrophication of freshwater had the highest normalized result (3.000), with nanoparticle synthesis contributing heavily, indicating the need for improved wastewater treatment. The resource use (minerals and metals) scored 1.856, while the freshwater ecotoxicity reached 80,317.23 CTUe, both driven by the nanoparticle production. The human toxicity potentials were 1.39 × 10⁻⁶ CTUh (cancer) and 7.45 × 10⁻⁵ CTUh (non-cancer), linked to emissions from synthesis and energy use. The LCA of the cosmetic cream revealed several critical areas of environmental impact. The most significant impacts are associated with gold nanoparticle synthesis and electricity use. Addressing these impacts through optimized synthesis processes, improved energy efficiency, and alternative materials can enhance the product’s sustainability profile significantly. Full article

Rare earth elements (REEs) are considered as emerging contaminants due to their use in the fabrication process of current technologies. As such, their aquatic toxicity, especially as a mixture, is not well understood, as it has been scarcely investigated. The purpose of this study was to shed light on the sublethal and lethal toxicity of a realistic mixture of five REE in Hydra vulgaris. The REE mixture was composed of five elements (Gd, Ce, Nd, Y and Dy, with a total REE concentration of 0.137 µg/L = 1× concentration) that were found in six municipal effluents in Canada at the same concentration ratios. The organisms were exposed to increasing concentrations (0.5, 1, 5, 10, 25, 50 and 100×) of the mixture for 96 h at 20 °C. The lethal and sublethal toxicities were evaluated by morphological changes and the gene expression (mRNA) involved in oxidative stress, damaged protein salvaging (autophagy for the reabsorption of damaged proteins), regeneration, neural activity and DNA repair of oxidatively damaged DNA. The data revealed that the total REE concentration of the environmental mixture was well below the lethal concentrations of the individual REEs, which occur generally at concentrations > 200 µg/L. This study proposes a novel gene transcription set to investigate the mode of action where gene expression changes occurred at concentrations below those reported in municipal effluents, suggesting long-term toxic effects in hydras close to municipal effluent discharges. This suggests that the release of REEs by municipal/hospital (for Gd) effluents should be more closely monitored. Full article

Agriculture and food production use very large amounts of plant protection products. These include insecticides, including pyrethroids, which belong to the third generation of pesticides. Although the ecotoxicity of these compounds is well known, their effect on environmental bacteria is still undefined. The aim of the presented research was to determine how permethrin can change the metabolism and surface properties of bacterial cells isolated from surface waters. Bacteria from water from a protected area (Snowy Ponds, Karkonosze National Park, Poland, 50°46′58″ N 15°33′47″ E) and a relatively polluted Kierskie Lake (52°27′10″ N 16°47′35″ E) next to the Poznań (Poland) agglomeration were compared. The obtained results showed that for the tested microorganisms, the toxic effect of permethrin is observed at 1000 ppm for water consortia and pure strains as well, except Bacillus thuringiensis KlaKry, which appeared to be resistant to the insecticide. What is more, the bacteria consortium from Kierskie Lake appeared to be more sensitive to insecticide, from the perspective of compound toxicity. At the same time, the metabolism assessed using EcoPlate™ showed that permethrin is not a factor determining the lower assimilation of various carbon sources, excluding carboxylic acids. Permethrin exposure also resulted in the decreased hydrophobicity of bacterial cells and increased permeability of their cell membrane. As a result, the obtained results show that if permethrin itself is not highly toxic, it can affect the properties of the cell wall and membrane. Consequently, it can potentially change the susceptibility of environmental bacteria to other xenobiotics. Full article

In recent years, the environmental impacts of plastic production and consumption have become increasingly significant, particularly due to their petroleum-based origins and the substantial waste management challenges they pose. Currently, global plastic waste production has reached 413.8 million metric tons across 192 countries, contributing notably to greenhouse gas emissions. Bioplastics have emerged as eco-friendly alternatives, with bioplastic carrier bags composed of 20% starch, 10% additives, and 70% polybutylene adipate terephthalate (PBAT) being the focus of this research. This study aimed to evaluate the biodegradation of these bioplastic bags under industrial composting conditions, addressing the gap in the existing literature that often lacks real-world applicability. A large-scale composting experiment was conducted using 37.5 tons of manure/wood and 50 tons of biopolymer bags over 12 weeks. Results showed that compost temperatures peaked at 70 °C and remained above 50 °C, pH levels stabilized at 8.16, and electrical conductivity was recorded at 1251 μs cm⁻¹. Significant changes were observed in key metrics, such as the carbon-to-nitrogen ratio and organic matter content. Disintegration tests revealed that 95% of the bags disintegrated by the 12th week, though ecotoxicity tests indicated varying germination inhibition rates. Advanced analytical methods (Fourier transform infrared spectroscopy, gas chromatography coupled with mass spectrometry) highlighted morphological and chemical transformations in the bags. This research enhances understanding of bioplastic degradation in real-world composting environments and suggests potential improvements to existing standards, promoting sustainable waste management solutions. Full article

Penconazole (C₁₂H₁₅Cl₂N₃) is widely used to prevent fungal infection of fruits. Since this toxic fungicide is recalcitrant to biological degradation, it has harmful impacts on aquatic ecosystems. TiO₂-based heterogeneous photocatalysis proved to be an efficient method for its mineralization. To monitor the processes occurring under the influence of illumination, the light absorbance, the pH, and the TOC of the samples were measured. The concentration of the model compound and the degradation products were determined by HPLC and IC. Penconazole did not decompose under UV light (λ_max = 371 nm) without a catalyst. In the presence of TiO₂, mineralization took place. The initial degradation rate in air (7.7 × 10⁻⁴ mM s⁻¹) was 5 times higher than under argon. The formation rate of hydrochloric acid (1.04 × 10⁻³ mM s⁻¹) in the former case significantly contributed to the acidification of the liquid phase. NH₄⁺ also formed, at the rate of 5.9 × 10⁻⁴ mM s⁻¹, and very slightly transformed to NO₃⁻. Due to the intermediates identified by HPLC-MS, hydroxylation, H abstraction, and Cl elimination are involved in the degradation mechanism, in which photogenerated HO^● radicals, conduction-band electrons, and (under air) superoxide radical anions (O₂^●−) play considerable roles. The intermediates proved to be much less toxic than penconazole. Full article

Nanoplastics are known to represent a threat to marine ecosystems. Their combination with other contaminants of emerging concerns (CECs) may amplify ecotoxic effects, with unknown impacts on marine biodiversity. This study investigates the effects, single and combined, of bisphenol A (BPA)—one of the most hazardous CECs—and polystyrene nanoparticles (PS NPs)—as a proxy for nanoplastics, being among the most commonly found asmarine debris—on cholinesterase (ChE) activities of the ascidian Ciona robusta. ChE activity was first measured in the siphons, tunic, and viscera of wild-caught adult specimens and exposed in vitro to BPA (0.01, 0.21, 0.69 mM) and PS NPs (0.0096–0.096 mM; 8.096 × 10⁹–10¹⁰ particles, respectively) alone and combined for 15 min of incubation. PS NPs’ behavior in milliQ water and in the ChE assay reaction buffer was characterized alone, combined with BPA, and analyzed through ζ-potential measurements via Dynamic Light Scattering. The results revealed that ChE activity was predominant in the viscera and siphons of C. robusta; PS NPs did not affect the ChE activity alone or combined, while BPA caused a concentration-dependent inhibition of ChE activity in the viscera. No changes in ζ-potential were observed for PS NPs alone or combined with BPA in the ChE buffer, suggesting no interaction. Further investigations are needed to understand the potential neurotoxic consequences for C. robusta and ecological risk scenarios due to exposure to BPA and nanoplastics in marine coastal waters. Full article

Anticoagulant rodenticides (ARs) have been used for eradication of mammals such as rats and mice on islands for more than three decades. Baits containing 25 to 50 parts per million of an AR (usually the second-generation anticoagulant brodifacoum) were aerially applied to 70% or more of the area on islands. In some areas, baits entered the seas. Many apparent coincidences between the AR bait applications and marine mammal strandings that were observed are summarized and discussed. The coincidences were not well studied and the associations between AR applications and mammal strandings have been understudied or denied. Such associations warrant a need to investigate whether AR applications are directly associated with marine mammal deaths and strandings, for which challenges are discussed. Monitoring marine ecosystems faces many challenges. This review calls for attention to consider and possibly establish a reasonable certainty of no harm for ecosystem restoration efforts. Cases potentially related to ARs are presented to illustrate the concept and the need of establishing such a certainty. Full article