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1.
Nat Commun ; 12(1): 2069, 2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33824308

RESUMO

The oxygenation of early Earth's atmosphere during the Great Oxidation Event, is generally accepted to have been caused by oceanic Cyanobacterial oxygenic photosynthesis. Recent studies suggest that Fe(II) toxicity delayed the Cyanobacterial expansion necessary for the GOE. This study investigates the effects of Fe(II) on two Cyanobacteria, Pseudanabaena sp. PCC7367 and Synechococcus sp. PCC7336, in a simulated shallow-water marine Archean environment. A similar Fe(II) toxicity response was observed as reported for closed batch cultures. This toxicity was not observed in cultures provided with continuous gaseous exchange that showed significantly shorter doubling times than the closed-culture system, even with repeated nocturnal addition of Fe(II) for 12 days. The green rust (GR) formed under high Fe(II) conditions, was not found to be directly toxic to Pseudanabaena sp. PCC7367. In summary, we present evidence of diurnal Fe cycling in a simulated shallow-water marine environment for two ancestral strains of Cyanobacteria, with increased O2 production under anoxic conditions.


Assuntos
Organismos Aquáticos/metabolismo , Archaea/metabolismo , Ritmo Circadiano , Ferro/metabolismo , Oxigênio/metabolismo , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/crescimento & desenvolvimento , Archaea/efeitos dos fármacos , Archaea/crescimento & desenvolvimento , Atmosfera , Clorofila A/metabolismo , Ferro/toxicidade , Modelos Biológicos , Água do Mar
2.
Science ; 372(6537): 81-84, 2021 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-33795455

RESUMO

Pesticide impacts are usually discussed in the context of applied amounts while disregarding the large but environmentally relevant variations in substance-specific toxicity. Here, we systemically interpret changes in the use of 381 pesticides over 25 years by considering 1591 substance-specific acute toxicity threshold values for eight nontarget species groups. We find that the toxicity of applied insecticides to aquatic invertebrates and pollinators has increased considerably-in sharp contrast to the applied amount-and that this increase has been driven by highly toxic pyrethroids and neonicotinoids, respectively. We also report increasing applied toxicity to aquatic invertebrates and pollinators in genetically modified (GM) corn and to terrestrial plants in herbicide-tolerant soybeans since approximately 2010. Our results challenge the claims of a decrease in the environmental impacts of pesticide use.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Produtos Agrícolas , Invertebrados/efeitos dos fármacos , Praguicidas/toxicidade , Plantas Geneticamente Modificadas , Plantas/efeitos dos fármacos , Animais , Herbicidas/toxicidade , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Piretrinas/toxicidade , Soja , Zea mays
3.
Ecotoxicol Environ Saf ; 208: 111677, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396009

RESUMO

CH3NH3PbI3 is one of the most widely studied and most promising photoelectric conversion materials for large-scale application. However, once it is discharged into the aquatic environment, it will release a variety of lethal substances to the aquatic organisms. Herein, two typical aquatic pollution indicators, Scenedesmus obliquus (a typical phytoplankton) and Daphnia magna (a typical zooplankton), were used to assess the acute effects of CH3NH3PbI3 perovskite on aquatic organisms. The results showed that, when the initial CH3NH3PbI3 perovskite level (CPL) was 40 mg L-1 or higher, the growth of S. obliquus would be remarkably inhibited with significant decreases of chlorophyll content and protein content. And when the CPL was over 5 mg L-1, the survival of D. magna would be notably threatened. Specifically, the 72 h EC-50 of CH3NH3PbI3 perovskite to S. obliquus was calculated as 37.21 mg L-1, and the 24 h LC-50 of this perovskite to D. magna adults and neonates were calculated as 37.53 mg L-1 and 18.55 mg L-1, respectively. Moreover, remarkably solution pH declination and large amounts of lead bio-accumulation was observed in the both acute experiments, which could be the main reasons causing the above acute effects. Considering the strong acute effects of these CH3NH3PbI3 perovskite materials and their attractive application prospect, more attentions should be paid on their harmness to the environment.


Assuntos
Compostos de Cálcio/toxicidade , Daphnia/efeitos dos fármacos , Chumbo/toxicidade , Metilaminas/toxicidade , Óxidos/toxicidade , Scenedesmus/efeitos dos fármacos , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/efeitos dos fármacos , Compostos de Cálcio/química , Humanos , Chumbo/química , Metilaminas/química , Óxidos/química , Propriedades de Superfície , Titânio/química , Testes de Toxicidade Aguda , Poluentes Químicos da Água/química
4.
Ecotoxicol Environ Saf ; 208: 111665, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396175

RESUMO

Microplastics are ubiquitous in aquatic ecosystems, but little information is currently available on the dangers and risks to living organisms. In order to assess the ecotoxicity of environmental microplastics (MPs), samples were collected from the beaches of two islands in the Guadeloupe archipelago, Petit-Bourg (PB) located on the main island of Guadeloupe and Marie-Galante (MG) on the second island of the archipelago. These samples have a similar polymer composition with mainly polyethylene (PE) and polypropylene (PP). However, these two samples are very dissimilar with regard to their contamination profile and their toxicity. MPs from MG contain more lead, cadmium and organochlorine compounds while those from PB have higher levels of copper, zinc and hydrocarbons. The leachates of these two samples of MPs induced sublethal effects on the growth of sea urchins and on the pulsation frequency of jellyfish ephyrae but not on the development of zebrafish embryos. The toxic effects are much more marked for samples from the PB site than those from the MG site. This work demonstrates that MPs can contain high levels of potentially bioavailable toxic substances that may represent a significant ecotoxicological risk, particularly for the early life stages of aquatic animals.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Estágios do Ciclo de Vida/efeitos dos fármacos , Microplásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/crescimento & desenvolvimento , Ecossistema , Ecotoxicologia , Ilhas , Microplásticos/química , Cifozoários/efeitos dos fármacos , Cifozoários/crescimento & desenvolvimento , Ouriços-do-Mar/efeitos dos fármacos , Ouriços-do-Mar/crescimento & desenvolvimento , Poluentes Químicos da Água/química
5.
Eur J Protistol ; 77: 125765, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33422944

RESUMO

Calmodulin (CaM) is one of the major Ca2+-binding proteins in the cells, and it plays multiple roles in several Ca2+ signaling pathways and regulating the activities of other proteins. In the present study, we characterized CaM genes from the marine dinoflagellates Amphidinium carterae, Cochlodinium polykrikoides, Prorocentrum micans, and P. minimum, and examined their expression patterns upon the addition and chelation of calcium. Their cDNAs had same ORF length (450 bp) and encoded the same protein, but with few nucleotide differences in the ORF and different 3'- and 5' untranslated regions (UTRs). The four CaM proteins consist of four EF-hand Ca2+-binding motifs, two N-terminal domains and two C-terminal domains, and they were highly conserved within eukaryotes. The CaM gene expressions in the tested species increased by calcium treatments; however, they were significantly down-regulated by the calcium-chelator EGTA. The CaM genes of the test species were inducible and regulated by different calcium doses, suggesting their major role in calcium regulation in dinoflagellates.


Assuntos
Organismos Aquáticos/genética , Cálcio/farmacologia , Dinoflagelados/efeitos dos fármacos , Dinoflagelados/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Organismos Aquáticos/efeitos dos fármacos , Calmodulina/genética , Perfilação da Expressão Gênica
6.
Anal Methods ; 13(5): 575-594, 2021 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-33507166

RESUMO

Active pharmaceutical ingredients (APIs) are increasingly being identified as contaminants of emerging concern (CECs). They have potentially detrimental ecological and human health impacts but most are not currently subject to environmental regulation. Addressing the life cycle of these pharmaceuticals plays a significant role in identifying the potential sources and understanding the environmental impact that pharmaceuticals may have in surface waters. The stability and biological activity of these "micro-pollutants" can lead to a pseudo persistence, with ensuing unknown chronic behavioural and health-related effects. Research that investigates pharmaceuticals predominantly focuses on their occurrence and effect within surface water environments. However, this review will help to collate this information with factors that affect their environmental concentration. This review focuses on six pharmaceuticals (clarithromycin, ciprofloxacin, sulfamethoxazole, venlafaxine, gemfibrozil and diclofenac), chosen because they are heavily consumed globally, have poor removal rates in conventional activated sludge wastewater treatment plants (CAS WWTPs), and are persistent in the aquatic environment. Furthermore, these pharmaceuticals are included in numerous published prioritisation studies and/or are on the Water Framework Directive (WFD) "Watch List" or are candidates for the updated Watch List (WL). This review investigates the concentrations seen in European Union (EU) surface waters and examines factors that influence final concentrations prior to release, thus giving a holistic overview on the source of pharmaceutical surface water pollution. A period of 10 years is covered by this review, which includes research from 2009-2020 examining over 100 published studies, and highlighting that pharmaceuticals can pose a severe risk to surface water environments, with each stage of the lifecycle of the pharmaceutical determining its concentration. This review additionally highlights the necessity to improve education surrounding appropriate use, disposal and waste management of pharmaceuticals, while implementing a source directed and end of pipe approach to reduce pharmaceutical occurrence in surface waters.


Assuntos
Mudança Climática , Pandemias , Preparações Farmacêuticas , Poluentes Químicos da Água , Animais , Organismos Aquáticos/efeitos dos fármacos , Indústria Farmacêutica , Ecotoxicologia , União Europeia , Humanos , /metabolismo , Preparações Farmacêuticas/isolamento & purificação , Preparações Farmacêuticas/metabolismo , Plantas/efeitos dos fármacos , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/farmacologia , Purificação da Água
7.
Ecotoxicol Environ Saf ; 208: 111612, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396132

RESUMO

Water quality standards are essential for regulation of contaminants in marine environment. Seawater quality criteria (SWQC) for arsenic (As), cadmium (Cd) and lead (Pb) have not been developed for India. The aim of this study is to derive the SWQC for the metals based on Species Sensitivity Distribution (SSD). Eight species of sensitive marine organisms belonging to five phyla were assessed for their sensitivity to toxicity of As, Cd and Pb. Median effective concentrations (EC50) and Median Lethal Concentrations (LC50) were derived from the acute toxicity bio-assays. No Observed Effect Concentrations (NOEC), Lowest Observed Effect Concentrations (LOEC) and chronic values were derived from chronic toxicity bio-assays. Diatoms were more sensitive to As with 96 h EC50 of 0.1 mg/l and copepods were more sensitive to Cd and Pb with 96 h EC50 of 0.019 mg/l and 0.05 mg/l respectively. Estimated NOECs ranged from 4.87 to 21.55 µg/l of As, 1.0 to 120 µg/l of Cd and 5.67 to 91.67 µg/l of Pb. Similarly, chronic values (µg/l) were in the range of 6.71-26.1, 1.38-170, and 7.67-91.67 of As, Cd and Pb respectively. The Criterion Maximum Concentration (CMC), Criterion Continuous Concentration (CCC) and Predicted No Effect Concentration (PNEC) values were prescribed as SWQC. The CMC (µg/l) of 19, 1.7 and 17 for As, Cd, and Pb were derived respectively for acute exposure during accidental marine outfalls. The CCC (µg/l) for As was 4.6, 1.1 for Cd and 5.9 for Pb are recommended as SWQC for protection of 95% of marine organisms. PNEC (µg/l) of 3.8 for As, 0.92 for Cd and 4.3 for Pb are suggested for highly disturbed ecosystems, shell fishing and mariculture uses of water bodies. These values are recommended as a baseline for site specific water quality criteria for the coastal waters of the country.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Arsênico/toxicidade , Cádmio/toxicidade , Chumbo/toxicidade , Água do Mar/química , Poluentes Químicos da Água/toxicidade , Qualidade da Água/normas , Animais , Arsênico/análise , Cádmio/análise , Copépodes/efeitos dos fármacos , Diatomáceas/efeitos dos fármacos , Ecossistema , Índia , Chumbo/análise , Dose Letal Mediana , Especificidade da Espécie , Poluentes Químicos da Água/análise
8.
Nanotoxicology ; 15(2): 257-275, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33503388

RESUMO

Safety on the use of magnetic nanomaterials (MNMs) has become an active topic of research given all the recent applications of these materials in various fields. It is known that the toxicity of MNMs depends on size, shape, and surface functionalization. In this study, we evaluate the biocompatibility with different aquatic organisms of engineered MNMs-CIT with excellent aqueous dispersion and long-term colloidal stability. Primary producers (the alga Pseudokirchneriella subcapitata), primary consumers (the rotifer Lecane papuana), and predators (the fish, Danio rerio) interacted with these materials in acute and sub-chronic toxicity tests. Our results indicate that P. subcaptita was the most sensitive taxon to MNMs-CIT. Inhibition of their population growth (IC50 = 22.84 mg L-1) elicited cell malformations and increased the content of photosynthetic pigments, likely due to inhibition of cell division (as demonstrated in AFM analysis). For L. papuana, the acute exposure to MNMs shows no significant mortality. However, adverse effects such as decreased rate of population and altered swimming patterns arise after chronic interaction with MNMs. For D. rerio organisms on early life stages, their exposure to MNMs results in delayed hatching of eggs, diminished survival of larvae, altered energy resources allocation (measured as the content of total carbohydrates, lipids, and protein), and increased glucose demand. As to our knowledge, this is the first study that includes three different trophic levels to assess the effect of MNMs in aquatic organisms; furthermore, we demonstrated that these MNMs pose hazards on aquatic food webs at low concentrations (few mgL-1).


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Cloretos/toxicidade , Compostos Férricos/toxicidade , Compostos Ferrosos/toxicidade , Nanoestruturas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/análise , Cloretos/química , Compostos Férricos/química , Compostos Ferrosos/química , Cadeia Alimentar , Larva/efeitos dos fármacos , Fenômenos Magnéticos , Microalgas/efeitos dos fármacos , Nanoestruturas/química , Tamanho da Partícula , Rotíferos/efeitos dos fármacos , Propriedades de Superfície , Poluentes Químicos da Água/química , Peixe-Zebra/crescimento & desenvolvimento
9.
Aquat Toxicol ; 231: 105708, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33341508

RESUMO

The WHAM-FTOX model quantifies cation toxicity towards freshwater organisms, assuming an additive toxic response to the amounts of protons and metals accumulated by an organism. We combined a parameterization of the model, using data from multi-species laboratory toxicity tests, with a fitted field species sensitivity distribution, to simulate the species richness (nsp) of crustacean zooplankton in acid- and metal-contaminated lakes near Sudbury, Ontario over several decades, and also in reference (uncontaminated) lakes. A good description of variation in toxic response among the zooplankton species was achieved with a log-normal distribution of a new parameter, ß, which characterizes an organism's intrinsic sensitivity towards toxic cations; the greater is ß, the more sensitive is the species. The use of ß assumes that while species vary in their sensitivity, the relative toxicities of different metals are the same for each species (common relative sensitivity). Unbiased agreements between simulated and observed nsp were obtained with a high correlation (r2 = 0.81, p < 0.0001, n = 217). Variations in zooplankton species richness in the Sudbury lakes are calculated to be dominated by toxic responses to H, Al, Cu and Ni, with a small contribution from Zn, and negligible effects of Cd, Hg and Pb. According to the model, some of the Sudbury lakes were affected predominantly by acidification (H and Al), while others were most influenced by toxic heavy metals (Ni, Cu, Zn); for lakes in the latter category, the relative importance of heavy metals, compared to H and Al, has increased over time. The results suggest that, if common relative sensitivity operates, nsp can be modelled on the basis of a single set of parameters characterizing the average toxic effects of different cations, together with a species sensitivity distribution.


Assuntos
Ácidos/toxicidade , Biodiversidade , Laboratórios , Lagos/química , Metais Pesados/toxicidade , Modelos Teóricos , Poluentes Químicos da Água/toxicidade , Zooplâncton/fisiologia , Animais , Organismos Aquáticos/efeitos dos fármacos , Crustáceos/efeitos dos fármacos , Monitoramento Ambiental , Ontário , Especificidade da Espécie , Estatística como Assunto , Fatores de Tempo , Zooplâncton/efeitos dos fármacos
10.
Aquat Toxicol ; 230: 105694, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33316747

RESUMO

Psychotropics, especially benzodiazepines, are commonly prescribed worldwide. Poorly eliminated at wastewater treatment plants, they belong to a group of emerging contaminants. Due to their interaction with the GABAA receptor, they may affect the function of the nervous system of non-target organisms, such as aquatic organisms. The toxicity of oxazepam, a very frequently detected benzodiazepine in continental freshwater, has been largely studied in aquatic vertebrates over the last decade. However, its effects on freshwater non-vertebrates have received much less attention. We aimed to evaluate the long-term effects of oxazepam on the juvenile stage of a freshwater gastropod widespread in Europe, Radix balthica. Juveniles were exposed for a month to environmentally-relevant concentrations of oxazepam found in rivers (0.8 µg/L) and effluents (10 µg/L). Three main physiological functions were studied: feeding, growth, and locomotion. Additionally, gene expression analysis was performed to provide insights into toxicity mechanisms. There was a strong short-term activation of the feeding rate at low concentration, whereas the high dose resulted in long-term inhibition of food intake. A significant decrease in mortality rate was observed in juveniles exposed to the lowest dose. Shell growth and locomotor activity did not appear to be affected by oxazepam. Transcriptomic analysis revealed global over-expression of genes involved in the nervous regulation of the feeding, digestive, and locomotion systems after oxazepam exposure. The molecular analysis also revealed a possible interference of animal manipulation with the molecular effects induced by oxazepam exposure. Overall, these results improve our understanding of the effects of the psychoactive drug oxazepam on an aquatic mollusc gastropod.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Gastrópodes/efeitos dos fármacos , Oxazepam/toxicidade , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/genética , Organismos Aquáticos/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Gastrópodes/genética , Gastrópodes/crescimento & desenvolvimento , Atividade Motora/efeitos dos fármacos , Oxazepam/análise , Rios/química , Poluentes Químicos da Água/análise
11.
Chemosphere ; 263: 127994, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32828062

RESUMO

Anthropogenic salinisation is becoming an increasing global issue for freshwater ecosystems, leading to serious biodiversity loss and ecosystem degradation. While the effect of anthropogenic salinisation on freshwater ecosystems has been intensively studied in recent years, most studies focus on salinisation effects on the individual or single groups of organisms without considering the effect on the ecosystem levels, such as diversity and trophic links. Therefore, we conducted a long-term field survey from May 2009 to August 2016 at 405 sites in northeast China to investigate the effect of a gradient of salinisation on community diversity, functional diversity and trophic links in mountain streams. Samples of water chemistry, periphyton, macroinvertebrates and fish were collected. Our results showed that as anthropogenic salinisation increased, Ca2+, Mg2+, HCO3- and SO42- exhibited significant increases (p < 0.05). These increased ions caused decreases in taxonomic evenness and biotic integrity, but an increase in the beta diversity for periphyton and macroinvertebrates, and a slight increase in the evenness of fish. The increased salinisation resulted in the extirpation of salt-sensitive taxa and declines in macroinvertebrate functional richness and functional redundancy, which consequently led to simplified trophic links. Our results implied that if salt-tolerant taxa in high salinisation sites were not functionally redundant with less tolerant taxa, alterations of their functional composition probably decrease the stability of ecosystem functions. Overall, our study suggests that the ongoing anthropogenic salinisation is posing serious threats to biodiversity and trophic links in river ecosystems, and should be considered in future river restoration and biodiversity conservation.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Biodiversidade , Chumbo/toxicidade , Microbiota/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , China , Ecossistema , Água Doce , Invertebrados/classificação , Chumbo/análise , Características de Residência , Rios/química , Poluentes Químicos da Água/análise
12.
Aquat Toxicol ; 228: 105632, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33010638

RESUMO

An experiment was carried out using microcosms to evaluate the impact of the fluoroquinolone antibiotic on nematode trophic groups structure and bacterial abundance. Sediment samples were experimentally enriched with four increasing doses of ciprofloxacin [D1 (50 ppm), D2 (100 ppm), D3 (200 ppm) and D4 (500 ppm)] and compared to non-enriched sediments (used as control). Ciprofloxacin changed the trophic composition of nematodes taxa where the relative abundance of microvores (M), epigrowth feeders (EF) and ciliate consumers (CF), raised in a control microcosm, was highly affected and significantly decreased in response to the increasing doses. Nevertheless, the abundance of deposit feeders (DF), optional predators (FP) and exclusive predators (Pr) showed a significant increase. Results from the multivariate analysis showed a clear impact of this antibiotic on nematode trophic assemblages. Microcosms treated with the three highest doses [D2, D3 and D4] were different from the control. The exceptions were those treated with the lowest dose, D1, and which were grouped with the control. The SIMPER analysis results showed that the average dissimilarity continuously increased in the treated microcosms compared to the control. Furthermore, our results have shown that ciprofloxacin also leads to a significant decrease in bacterial density with the highest dose, which could explain the results obtained for nematode trophic groups distribution. Thus, the bacteriophages nematodes only use bacteria as a nutrition source and the lack or presence in small quantity of this food could induce a decrease in their abundance as well as changing of nematodes groups repartition. Our work demonstrates that the nematode responses were dependent on sediment enrichment with ciprofloxacin and opens new perspectives on the potential impact of antibiotics on functional nematode diversity.


Assuntos
Antibacterianos/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Ciprofloxacino/toxicidade , Ecossistema , Sedimentos Geológicos/química , Nematoides/fisiologia , Animais , Bactérias/efeitos dos fármacos , Análise por Conglomerados , Geografia , Sedimentos Geológicos/microbiologia , Região do Mediterrâneo , Análise Multivariada , Nematoides/efeitos dos fármacos , Densidade Demográfica , Análise de Componente Principal , Poluentes Químicos da Água/toxicidade
13.
Aquat Toxicol ; 228: 105646, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33011648

RESUMO

2,4-dinitrophenol (2,4-DNP) is a phenolic compound used as a wood preservative or pesticide. The chemical is hazardous to freshwater organisms. Although 2,4-DNP poses ecological risks, only a few of its aquatic environmental risks have been investigated and very limited guidelines for freshwater aquatic ecosystems have been established by governments. This study addresses the paucity of 2,4-DNP toxicity data for freshwater ecosystems and the current lack of highly reliable trigger values for this highly toxic compound. We conducted acute bioassays using 12 species from nine taxonomic groups and chronic assays using five species from four taxonomic groups to improve the quality of the dataset and enable the estimation of protective concentrations based on species sensitivity distributions. The acute and hazardous concentrations of 2,4-DNP in 5% of freshwater aquatic species (HC5) were determined to be 0.91 (0.32-2.65) mg/L and 0.22 (0.11-0.42) mg/L, respectively. To the best of our knowledge, this is the first report of a suggested chronic HC5 for 2,4-DNP and it provides the much-needed fundamental data for the risk assessment and management of freshwater ecosystems.


Assuntos
2,4-Dinitrofenol/análise , Ecossistema , Monitoramento Ambiental , Água Doce/química , Praguicidas/toxicidade , Poluentes Químicos da Água/análise , Animais , Organismos Aquáticos/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Chlamydomonas/efeitos dos fármacos , Clorofíceas/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Euglena/efeitos dos fármacos , Oryzias , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Especificidade da Espécie , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Qualidade da Água
14.
Aquat Toxicol ; 228: 105650, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33035767

RESUMO

Micro(nano)plastics (MPs/NPs) are already present as contaminants in the natural environment globally and have been shown to be difficult to degrade, resulting in the potential for ecological damage and public health concerns. However, the adverse effects of exposure to MPs/NPs by aquatic organisms, especially freshwater microalgae, remains unclear. In the present study, the growth, physiology and transcriptome of the freshwater microalgae Euglena gracilis were comprehensively analyzed following exposure to 1 mg/L of polystyrene (PS) microbeads (5 µm PS-MPs and 100 nm PS-NPs), 0.5 mg/L cadmium (Cd), or a mixture of PS microbeads and Cd for 96 h. Results showed that the toxicity of PS-MPs to microalgae was greater than PS-NPs, inducing increased growth inhibition, oxidative damage and decreased photosynthesis pigment concentrations. PS-MPs alone or in combination with Cd caused cavitation within microalgal cells, as well as increasing the number and volume of vacuoles. The combined exposure toxicity test showed that a combination of Cd + PS-NPs was more toxic than Cd + PS-MPs, which may be explained by the transcriptomic analysis results. Differentially expressed genes (DEGs) in the Cd + PS-NPs group were mainly enriched in metabolism-related pathways, suggesting that algal metabolism was hindered, resulting in aggravation of toxicity. The reduced toxicity induced by Cd + PS-MPs may indicate a response to resist external stress processes. In addition, no adsorption of 0.5 mg/L Cd to 1 mg/L PS microbeads was observed, suggesting that adsorption of MPs/NPs and Cd was not the key factor determining the combined toxicity effects in this study.


Assuntos
Cádmio/toxicidade , Exposição Ambiental , Euglena gracilis/genética , Euglena gracilis/fisiologia , Microalgas/genética , Microesferas , Poliestirenos/toxicidade , Transcrição Genética/efeitos dos fármacos , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/genética , Organismos Aquáticos/crescimento & desenvolvimento , Euglena gracilis/efeitos dos fármacos , Euglena gracilis/ultraestrutura , Perfilação da Expressão Gênica , Ontologia Genética , Microalgas/efeitos dos fármacos , Microalgas/fisiologia , Microalgas/ultraestrutura , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Pigmentos Biológicos/metabolismo , Poluentes Químicos da Água/toxicidade
15.
Bull Environ Contam Toxicol ; 105(5): 665-670, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33052433

RESUMO

A key step in deriving an Environmental Quality Standard (EQS) is assessing the reliability and relevance of the underpinning ecotoxicity data. While the assessment of data reliability is relatively well established, the detailed evaluation of data relevancy is a more recent development. We applied broadly accepted relevancy criteria to a series of non-standard ecotoxicity studies on diclofenac, focusing on some aspects that should be accounted for in studies used in EQS derivation. Specific relevancy issues include potential experimental bias, claimed 'significant effects' that are indistinguishable from controls, or within the range of normal, and lack of environmental applicability. We highlight that rigorous, comprehensive and, where necessary, specialist assessment of data relevancy for studies potentially applicable for EQS setting is critical if studies are to be appropriately used regulatory decision-making. We provide recommendations for researchers and environmental practitioners to ensure robust accounting of relevancy in non-standard studies is undertaken.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Diclofenaco/toxicidade , Ecotoxicologia/normas , Monitoramento Ambiental/normas , Poluentes Químicos da Água/toxicidade , Animais , Diclofenaco/análise , Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Humanos , Reprodutibilidade dos Testes , Testes de Toxicidade , Poluentes Químicos da Água/análise , Qualidade da Água/normas
16.
Int J Nanomedicine ; 15: 8097-8108, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33116520

RESUMO

Background: Metallic nanoparticles (NPs) are highly exploited in manufacturing and medical processes in a broad spectrum of industrial applications and in the academic sectors. Several studies have suggested that many metallic nanomaterials including those derived by silver (Ag) are entering the ecosystem to cause significant toxic consequences in cell culture and animal models. However, ecotoxicity studies are still receiving limited attention when designing functionalized and non.-functionalized AgNPs. Objective: This study aimed to investigate different ecotoxicological profiles of AgNPs, which were analyzed in two different states: in pristine form uncoated AgNPs and coated AgNPs with the antimicrobial peptide indolicidin. These two types of AgNPs are exploited for a set of different tests using Daphnia magna and Raphidocelis subcapitata, which are representatives of two different levels of the aquatic trophic chain, and seeds of Lepidium sativum, Cucumis sativus and Lactuca sativa. Results: Ecotoxicological studies showed that the most sensitive organism to AgNPs was crustacean D. magna, followed by R. subcapitata and plant seeds, while AgNPs coated with indolicidin (IndAgNPs) showed a dose-dependent decreased toxicity for all three. Conclusion: The obtained results demonstrate that high ecotoxicity induced by AgNPs is strongly dependent on the surface chemistry, thus the presence of the antimicrobial peptide. This finding opens new avenues to design and fabricate the next generation of metallic nanoparticles to ensure the biosafety and risk of using engineered nanoparticles in consumer products.


Assuntos
Peptídeos Catiônicos Antimicrobianos/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Ecossistema , Ecotoxicologia , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Animais , Peptídeos Catiônicos Antimicrobianos/síntese química , Crustáceos/efeitos dos fármacos , Cucumis sativus/efeitos dos fármacos , Cucumis sativus/crescimento & desenvolvimento , Daphnia/citologia , Daphnia/efeitos dos fármacos , Germinação/efeitos dos fármacos , Lepidium/efeitos dos fármacos , Lepidium/crescimento & desenvolvimento , Alface/efeitos dos fármacos , Alface/crescimento & desenvolvimento , Nanopartículas Metálicas/ultraestrutura , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Testes de Toxicidade
17.
Aquat Toxicol ; 227: 105569, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32916319

RESUMO

Pharmaceuticals are widespread contaminants across the aquatic systems and despite the role that these compounds play in society today, little is known about their effects in aquatic organisms once they are released into the environment. This study aims to provide quantitative insight on the effects of antidepressants on the reproduction of fish and crustaceans with a multilevel meta-analysis. A systematic literature search identified 19 studies investigating effects of antidepressant exposure in fish or crustaceans' reproduction, according to specific selection criteria. Heterogeneity analysis was performed and the moderating effect of the range of exposure concentrations, exposure time, organism group and toxicant was tested. Additionally, publication bias was also addressed. The results showed that, overall, there is no significant association between antidepressant exposure and the reproduction of fish and crustaceans, however, moderator analysis revealed that the range of concentrations is a significant moderator for fish and crustacean fecundity, showing contrary results between the two groups. Antidepressant concentration had a small, yet positive effect on fish fecundity, meaning that increased concentrations resulted in increased fish fecundity, whilst a negative effect on crustaceans' fecundity was apparent with increasing concentrations. This difference could be related to data artifacts, or, more likely, evidencing a hormetic dose-response curve, with different ranges of exposure concentrations considered in studies on fish and crustaceans. Antidepressants have shown effects on reproductive outcomes in aquatic organisms, based on individual studies and narrative reviews. However, our results show that other factors can have an important role. Additionally, data available for a quantitative assessment is scarce, focusing mainly on a few freshwater species, low concentration ranges and one SSRI compound, fluoxetine. Thus, more research on the subject is needed since meta-analysis are only as statistically powerful as the number of, good quality, studies they include.


Assuntos
Antidepressivos/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Fluoxetina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/fisiologia , Crustáceos/efeitos dos fármacos , Peixes/crescimento & desenvolvimento , Água Doce/química , Reprodução/efeitos dos fármacos
18.
Ecotoxicol Environ Saf ; 205: 111291, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32956865

RESUMO

The purpose of this study was to determine the acute toxicity in aquatic organisms of one biocidal active substance and six metabolites derived from biocidal active substances and to assess the suitability of available QSAR models to predict the obtained values. We have reported the acute toxicity in sewage treatment plant (STP) microorganisms, in the freshwater microalgae Pseudokirchneriella subcapitata and in Daphnia magna following OECD test methods. We have also identified in silico models for acute toxicity of these trophic levels currently available in widely recognized platforms such as VEGA and the OECD QSAR ToolBox. A total of six, four and two models have been selected for Daphnia, algae and microorganisms, respectively. Finally, we have compared the in silico and in vivo data for the seven compounds plus two previously assayed biocidal substances. None of the compounds tested were toxic for Daphnia and STP microorganisms. For microalgae, CGA71019 (1,2,4 triazole) presented an ErC50 value of 38.3 mg/L. The selected in silico models have provided lower EC50 values and are therefore more conservative. Models from the OECD QSAR ToolBox predicted values for 7 out of 9 and for 4 out of 9 chemicals for Daphnia and P. subcapitata, respectively. No predictive models were identified in such platform for STP microorganism's acute effects. In terms of models's specificity, biocide-specific models, developed from curated datasets integrated by biocidal active substances and implemented in VEGA, perform better in the case of microalgae but for Daphnia an alternative, non biocide-specific has revealed a better performance. For STP microorganisms only biocide-specific models have been identified.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Desinfetantes/toxicidade , Modelos Biológicos , Poluentes Químicos da Água/toxicidade , Animais , Clorofíceas/efeitos dos fármacos , Simulação por Computador , Daphnia/efeitos dos fármacos , Desinfetantes/química , Desinfetantes/metabolismo , Água Doce/química , Microalgas/efeitos dos fármacos , Relação Quantitativa Estrutura-Atividade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo
19.
Aquat Toxicol ; 227: 105595, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32911330

RESUMO

In order to understand the potential impacts of nickel nanowires (Ni NWs) after reaching the aquatic environment, this research evaluated the toxicity of Ni NWs with different lengths (≤ 1.1, ≤11 and ≤ 80 µm) for several floating, planktonic and nektonic freshwater organisms. In this work, Ni NWs were synthesized by electrodeposition using anodized aluminum oxide (AAO) membranes. The toxicity of the NWs was assessed using a battery of aquatic species representative of key functions at the ecosystem level: the bacterium Aliivibrio fischeri, the algae Raphidocelis subcapitata, the macrophyte Lemna minor, the crustacean Daphnia magna and the zebrafish Danio rerio. Results indicated that for the concentrations tested (up to 2.5 mg L-1) the synthesized Ni NWs showed low toxicity. And although no lethal toxicity was observed for D. magna, at a sublethal level the feeding activity of the freshwater cladoceran was severely affected after exposure to Ni NWs. These findings showed that NWs can be accumulated in the gut of D. magna, even during a short exposure (24 h) directly impairing Daphnia nutrition and eventually populations growth. Consequently, this can also contribute to trophic transfer of NWs along the food chain. According to our results the toxicity of Ni NW may be mainly attributed to physical effects rather than chemical effects of Ni ions, considering that the concentrations of Ni NWs tested in this study were well below the toxicity thresholds reported in the literature for Ni ions and for Ni NMs.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Nanofios/toxicidade , Níquel/toxicidade , Purificação da Água/métodos , Aliivibrio fischeri , Animais , Clorofíceas , Daphnia/efeitos dos fármacos , Ecossistema , Cadeia Alimentar , Água Doce , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
20.
Aquat Toxicol ; 228: 105630, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32971354

RESUMO

Bitumen mined in the oil sands region of Northern Alberta, Canada, is diluted with natural gas condensates to form dilbit, which is transported through pipelines. Sections of these pipelines come close to freshwater ecosystems. If dilbit is spilled into or near an aquatic environment, environmental weathering processes, such as evaporation and sediment interaction, influence the fate and toxicity of dilbit to aquatic organisms. To date, most studies of the effects of dilbit on the health of aquatic organisms have not considered weathering processes. Thus, the goal of this study was to assess the toxicity of weathered sediment-bound dilbit (WSD) to an aquatic organism. Adult freshwater amphipods (Hyalella azteca) were exposed directly to WSD or the water-soluble fraction (WSF) of WSD. Direct exposure to WSD resulted in oil-mineral aggregates adhering to the appendages and gas exchange structures of amphipods, causing acute lethality. After a 10-min exposure to WSD, amphipods consumed half as much oxygen and their appendage movement was impaired. Exposure to the WSF, which contained a total PAH concentration of 1.08 µg/L, did not result in acute lethality, or significantly affect respiration, activity or acetylcholinesterase activity. Results of the present study indicate that physical interaction with oil-mineral aggregates after a spill of dilbit is a threat to benthic invertebrates, whereas the WSF does not cause acute adverse effects. As the transport of dilbit through pipelines increases in North America, studies must incorporate environmental weathering processes when determining the effects of dilbit on aquatic organisms.


Assuntos
Anfípodes/efeitos dos fármacos , Água Doce , Sedimentos Geológicos/química , Poluentes Químicos da Água/toxicidade , Alberta , Animais , Organismos Aquáticos/efeitos dos fármacos , Ecossistema , Consumo de Oxigênio/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Solubilidade , Água/química
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