The widespread use of levofloxacin (LEV) and oxytetracycline (OTC) in hospitals and farms inevitably contributes to water pollution through waste disposal processes, municipal wastewater treatment, ...and manure application to farmlands, which adversely affects aquatic microorganisms. Here, we evaluated the toxicity of LEV and OTC to cyanobacteria and eukaryotic algae monocultures and freshwater microcosms. Three test cyanobacteria were inhibited by both LEV and OTC at all examined concentrations. The growth of the eukaryotic organisms C. vulgaris and Monoraphidium sp. was only inhibited by high concentrations of OTC ranging from 1000 to 10,000 μg/L; however, they were less sensitive to LEV and OTC than cyanobacteria. In the aquatic microcosms, 5 μg/L of LEV and OTC did not affect the alpha diversity of prokaryotic and eukaryotic communities or the composition of the eukaryotic microbial communities after 14 d of exposure. However, this concentration of LEV and OTC significantly changed the prokaryotic microbial community structure at the genus level, and different antibiotics affected the prokaryotic microbial community differently, suggesting that different antibiotics affect prokaryotes through different molecular mechanisms, thereby leading to differences in prokaryotic microbial growth patterns. Moreover, the changes in the prokaryotic microbial community composition suggested that low antibiotic concentrations in water could disturb prokaryotic microbial communities and cause ecological risks.
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•Eukaryotic algae were less sensitive to LEV and OTC than cyanobacteria.•LEV and OTC at 5 μg/L sharply changed the prokaryotic microbial community structure.•Prokaryotic microbial community structure changed differently after LEV and OTC exposure.
Progress in the development of biodegradable or biobased ionic liquids (ILs) has led to the design of green compounds for several applications. Herein, four biocompatible dicationic ionic liquids ...(DILs) with ammonium-phosphonium cations and amino acid anions were synthesized and investigated their environmental impact. The structures of the DILs were confirmed by spectral analyses (1H, 13C and 31P NMR). Furthermore, physicochemical properties such as density, viscosity and refractive index were determined. Water content, bromide content and solubility were thereafter determined as the parameters needed for further studies. Subsequently, their antifeedant activity towards economically important pests of grain in storage warehouses: the granary weevil, the confused flour beetle, and the khapra beetle was examined, showing the dependence on structure. Moreover, selected DILs were investigated for toxicity towards white mustard, Daphnia magna, and Artemia franciscana to specify the environmental impact. These studies were complemented by understand the biodegradation of DILs by bacterial communities derived from soil at the agricultural land. The result was DILs with limited environmental footprints that have great potential for further application studies.
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•A novel approach to synthesizing dicationic ionic liquids with ammonium-phosphonium cation was presented.•Spectral analysis (1H, 13C, and 31P NMR) was used to characterize the structure of the synthesized dicationic ionic liquids.•Ecotoxicological assessment of the impact of dicationic ionic liquids on storage pests, plant, and crustaceans was carried out.•The biodegradability of dicationic ionic liquids was investigated to assess their influence in the environment.
New mixtures of pesticides are being placed on the market to increase the spectrum of phytosanitary action. Thus, the eco(geno)toxic effects of the new commercial mixture named Platinum Neo, as well ...as its constituents the neonicotinoid Thiamethoxam and the pyrethroid Lambda-Cyhalothrin, were investigated using the species Daphnia magna, Raphidocelis subcapitata, Danio rerio, and Allium cepa L. The lowest- and no-observed effect concentration (LOEC and NOEC) were measured in ecotoxicological tests. While Thiamethoxam was ecotoxic at ppm level, Lambda-Cyhalothrin and Platinum Neo formulation were ecotoxic at ppb level. The mitotic index (MI), chromosomal aberrations and micronucleus MN frequency were measured as indicators of phytogenotoxicity in A. cepa plants exposed for 12 h to the different insecticides and their mixture under different dilutions. There were significant alterations in the MI and MN frequency in comparison with the A. cepa negative control group, with Thiamethoxam, Lambda-Cyhalothrin, and Platinum Neo treatments all significantly reducing MI and increasing MN frequency. Thus, MI reduction was found at 13.7 mg L−1 for Thiamethoxam, 0.8 μg L−1 for Lambda-Cyahalothrin, and 2.7:2 μg L−1 for Platinum Neo, while MN induction was not observed at 14 mg L−1 for Thiamethoxam, 0.8 μg L−1 for Lambda-Cyahalothrin, and 1.4:1 μg L−1 for Platinum Neo. The insecticide eco(geno)toxicity hierarchy was Platinun Neo > Lambda-Cyhalothrin > Thiamethoxam, and the organism sensitivity hierarchy was daphnids > fish > algae > A. cepa. Eco(geno)toxicity studies of new pesticide mixtures can be useful for management, risk assessment, and avoiding impacts of these products on living beings.
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•The eco(geno)toxicity of the new insecticide mixture Platinum Neo was studied.•Platinum Neo is a combination of a neonicotinoid and a pyrethroid compounds.•The NOEC of Thiamethoxam for genotoxicity endpoint was 14 mg L−1•The NOEC of Lambda-Cyhalothrin for genotoxicity endpoint was 0.8 μg L−1•The eco(geno)toxicity hierarchy was Platinun Neo > λ-Cyhalothrin > Thiamethoxam.
Anthelmintics are drugs used for the treatment and prevention of diseases caused by parasitic worms (helminths). While the importance of anthelmintics in human as well as in veterinary medicine is ...evident, they represent emerging contaminants of the environment. Human anthelmintics are mainly used in tropical and sub-tropical regions, while veterinary anthelmintics have become frequently-occurring environmental pollutants worldwide due to intensive agri- and aquaculture production. In the environment, anthelmintics are distributed in water and soil in relation to their structure and physicochemical properties. Consequently, they enter various organisms directly (e.g. plants, soil invertebrates, water animals) or indirectly through food-chain. Several anthelmintics elicit toxic effects in non-target species. Although new information has been made available, anthelmintics in ecosystems should be more thoroughly investigated to obtain complex knowledge on their impact in various environments. This review summarizes available information about the occurrence, behavior, and toxic effect of anthelmintics in environment. Several reasons why anthelmintics are dangerous contaminants are highlighted along with options to reduce contamination. Negative effects are also outlined.
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•Anthelmintics enter the environment mainly through human and animal excretion.•Anthelmintics persist in soil and/or leach into water and/or are metabolized by living organisms.•Some anthelmintics are ecotoxic, they effect predominantly dung invertebrates.•Anthelmintics circulate in the environment and in food-chains.•The impact of anthelmintics on non-target organisms needs to be investigated more thoroughly.
Vibrio fischeri bioluminescence inhibition bioassay (VFBIA) has been widely applied for the monitoring of toxicity on account of multiple advantages encompassing shorter test duration, sensitive, ...cost-effective and ease of operation. Moreover, this bioassay found to be equally applicable to all types of matrices (organic & inorganic compounds, metals, wastewater, river water, sewage sludge, landfill leachate, herbicides, treated wastewater etc.) for toxicity monitoring. This review highlights the apparent significance of Vibrio fischeri bioluminescence inhibition assay for ecotoxicological screening and evaluation of diverse chemical substances toxicity profile. The biochemical and genetic basis of the bioluminescence assay and its regulatory mechanism have been concisely discussed. The basic test protocol with ongoing improvements, widespread applications, typical advantages and probable limitations of the assay have been overviewed. The sensitivity of VFBIA and toxicity bioassays has also been compared.
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•Vibrio fischeri bioluminescence inhibition assay for ecotoxicity assessment was overviewed.•Efficiency was compared with other bioassays used for toxicity evaluation.•The basic protocol, subsequent modifications, applications, advantages and limitations are discussed.•V. fischeri proves to be sensitive for toxicity monitoring of all types of matrices.
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•Enhanced oxidation and TOC removal were observed with high concentrations Cl−.•Both SO4− and OH were found responsible for MeP degradation without Cl−.•Cl2− dominated the MeP ...degradation process at a high Cl− level.•Four main reaction pathways were proposed and 15 products identified.•ECOSAR analysis indicated the ecotoxicity of most products were smaller than MeP.
Chloride ion (Cl−) widely presents in natural water and wastewater, which can significantly affect the performance of sulfate radical-based advanced oxidation processes (SR-AOPs). However, few studies are available now on the generation of chlorinated by-products in the peroxymonosulfate (PMS) based systems. Here a novel catalyst (cobalt/carbon nanotubes, Co/CNTs) was synthesized and used as a PMS activator to remove methylparaben (MeP) with and without Cl−. The morphology and chemical composition of the fresh and used Co/CNTs were characterized by TEM, SEM, XRD, BET, and XPS. Results revealed that Co/CNTs exhibited significant catalytic activity toward MeP removal, and the removal efficiency increased with the augment of reaction temperature and concentrations of Co/CNTs and PMS. In the absence of Cl−, 83.2% of 10 μM MeP was degraded within 60 min by using 2 mg/L Co/CNTs and 100 μM PMS at 25 °C with pH 7.0. However, complete removal of MeP was achieved within 20 min in the presence of 100 mM Cl−, which enhanced the apparent rate constant by a factor of 4.3. Consequently, TOC removal was enhanced from 8.1% to 19.2% within 60 min. Through the quenching experiments, both SO4− and OH were found responsible for MeP degradation without Cl−, while Cl2− was the main reactive oxygen species (ROS) with 100 mM Cl−. Based on the intermediates identified via TOF-LC-MS, four potential reaction pathways were proposed, including hydrogen abstraction coupling reaction, hydroxylation, OH attack, and Cl2− attack. The intermediates also exhibited decreased toxicity compared to the parent compound based on the ecotoxicity evaluation. In addition, Co/CNTs + PMS system achieved over 60% MeP removal from real wastewater with elevated PMS concentration, indicating the process applicability. These findings provide valuable information of SR-AOPs to facilitate organic contaminants removal in Cl−-containing water.
In recent years, antibiotics have been used for human and animal disease treatment, growth promotion, and prophylaxis, and their consumption is rising worldwide. Antibiotics are often not fully ...metabolized by the body and are released into the aquatic environment, where they may have negative effects on the non-target species. This review examines the recent researches on eight representative antibiotics (erythromycin, trimethoprim, sulfamethoxazole, tetracycline, oxytetracycline, ofloxacin, ciprofloxacin, and amoxicillin). A detailed overview of their concentrations in surface waters, groundwater, and effluents is provided, supported by recent global human consumption and veterinary use data. Furthermore, we review the ecotoxicity of these antibiotics towards different groups of organisms, and assessment of the environmental risks to aquatic organisms. This review discusses and compares the suitability of currently used ecotoxicological bioassays, and identifies the knowledge gaps and future challenges. The risk data indicate that selected antibiotics may pose a threat to aquatic environments. Cyanobacteria were the most sensitive organisms when using standard ecotoxicological bioassays. Further studies on their chronic effects to aquatic organisms and the toxicity of antibiotic mixtures are necessary to fully understand the hazards these antibiotics present.
•Recent global human consumption and veterinary use of antibiotics are presented.•Ecotoxicity of antibiotics towards different groups of organisms is given.•Assessment of the environmental risks of antibiotics to aquatic organisms is discussed.•Cyanobacteria are the most sensitive organisms in standard ecotoxicological bioassays.
Industrial metal-rich sludge can improve soil properties, but it is potentially toxic to soils and adjacent aquatic systems. The soil-sludge-water interactions influence metals bioavailability over ...time, a phenomenon mostly regulated by the still debatable “sludge physical protection” or “sludge delayed release” hypotheses. The present study aimed to investigate: (1) whether sludge increases soil aggregate stability against slaking, (2) which hypothesis mostly regulates metal release from soils to water and (3) the ecotoxicity of the metals released during soil slaking for aquatic organisms. Under a realistic field scale, soils amended with an industrial sludge or spiked with equivalent metal solutions (of Cr, Cu, Ni, Zn) were collected over three months to test soil aggregate stability, the ecotoxicity of the slaking water and metal contents in soil and water. The “sludge physical protection” was verified for all metals, though for Cu the “sludge delayed release” hypothesis appears plausible after three months. Soil amendment with sludge did not lead to effects on the growth of the microalga Raphidocelis subcapitata, contrarily to the observed for the metal-spiked soil. Criteria regulating soils sludge-amendment management should thus include doses not hazardous to biota, and not only metal threshold levels.
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•Industrial metal-rich sludge used to amend agricultural soils can contaminate aquatic systems.•Soil aggregate stability was not enhanced by metal-contaminated sludge amendment.•The sludge physical protection hypothesis was valid for all metals over 3 months.•The sludge delayed release hypothesis was plausible for Cu (not Cr, Zn, Ni) over 2 years.•Only slaking water from the highest-metal dose spiked soil inhibited the growth of R. subcapitata.
The present study reports the development of a bioassay using Artemia spp. to analyse the preliminary ecotoxicity of atmospheric aerosols (PM), which can affect the environment and human health. ...Herein, PM samples were collected in the city of Goiânia (Brazil) in 2016, extracted with ultrapure water and subsequently filtered through membranes with different pore sizes (100, 0.8, and 0.22 μm), and the extracts employed in the bioassays. The mortality rates (endpoint analysed) declined to membranes with smaller pore sizes (15 ± 4%, 47 ± 10% and 43 ± 9% for pore sizes of 100 μm, 0.8 μm and 0.22 μm, respectively). In general, the toxicity of the extract depended on its concentration, except for the sample with a higher negative particle surface charge, which presents a lower affinity for the negatively charged surfaces of cellular membranes. Moreover, although the PM concentration was higher for the sample collected during the dry season (September), the mortality rate was not significantly different to that determined for a sample with similar physical and chemical characteristics collected in the rainy season (December). This result demonstrates the importance of monitoring PM toxicities and their chemical and physical characteristics, in addition to their concentrations. Therefore, the new protocol to provide a preliminary analysis of the toxicity of the extracts of aerosol emerges as a useful, accessible, and fast tool for monitoring possible environmental hazards, and can simplify fieldwork.
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•A new protocol to measure the preliminary ecotoxicity of atmospheric aerosol samples.•The ecotoxicological impact of atmospheric aerosol upon Artemia spp.•Aerosol samples collected in the dry and wet seasons exhibit ecotoxicity.•The toxicity showed dependence on particle size and concentration.
Riparian sediment is the last barrier preventing contaminants from polluting aquatic ecosystems. Recently, microplastics (MPs) have frequently been found in sediments. However, the MP aging process ...and its impact on sediments remain unknown. This study aimed to identify the key driving factors and mechanisms of riparian sediment on MPs aging behavior. The results showed that MPs surface suffered heavy breakage and the oxygen-to-carbon ratio of MPs increased by 268 % after accumulation in sediment for 214 d. The carbonyl index revealed that the degree of MP aging driven by dissolved organic matter (DOM) was 6.7–83.6 % greater than that of colloids, indicating that DOM was the key sediment fraction driving MP aging. Sunlight was an important environmental factor that enhanced MPs aging by sediment fractions, because photo-irradiated DOM produced hydroxyl and superoxide radicals to damage the MPs structure. Benzoic acid, dibenzoylmethane, and 4-heptyl-4,6-diphenyl-tetrahydro-pytan-2-one were the main products during the MP aging process under the interaction of sunlight and DOM, which showed acute toxicity to aquatic organisms and caused more severe toxicity during the chronic period. These results clearly clarify the behavior and environmental risk of MPs after accumulation in sediment, providing guide information to control MP pollution in the riparian zone.
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•This is the first study on MPs aging process driven by sediment fractions.•DOM is the key fraction of sediment driving MPs aging process.•Light enhanced the aging degree of MPs driven by sediment fraction.•O−2• make MPs to excite state and then OH• attack MPs surface and structure.•Photoaging product shows acute and chronic ecotoxicity to aquatic organism.
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