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1.
Sci Total Environ ; 784: 147262, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34088027

RESUMO

The rising use of contaminants such as nanoparticles and microplastics has taken a heavy toll on the marine environment. However, their combined toxic effects on the species across various trophic levels remain quite unexplored. The aim of this study was to explore the effects of three surface-functionalized (carboxylated, plain, and aminated) polystyrene microplastics on nano-TiO2 toxicity across two trophic levels containing Chlorella sp. as the prey and Artemia salina as the predator. The experiments carried out on Chlorella sp. include the toxicity assessment, oxidative stress determination, and uptake of nano-TiO2 (both in the presence and absence of microplastics). Results revealed that the aminated and plain polystyrene microplastics enhanced nano-TiO2 toxicity, while carboxylated microplastics decreased the toxic effects in Chlorella sp. On the other hand, toxicity assessment in Artemia salina was carried out using two different modes of exposure: aqueous and dietary routes. The aqueous route involving the direct exposure of nano-TiO2 and microplastics indicated greater toxicity, uptake, and accumulation in Artemia salina than the dietary route of exposure. Since dietary exposure decreased the toxicity, uptake, and accumulation of nano-TiO2, no change (p > 0.05) in the biomagnification factors of nano-TiO2 was noted for all the test concentrations of nano-TiO2 combined with and without microplastics. The computed values were less than 1, indicating negligible transfer of nano-TiO2 from Chlorella sp. to Artemia salina. Overall, the study highlights the two-level trophic toxicity and the transfer potential of nano-TiO2 under the influence of different microplastics.


Assuntos
Chlorella , Nanopartículas , Poluentes Químicos da Água , Microplásticos , Plásticos , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade
2.
Sci Total Environ ; 784: 147162, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34088035

RESUMO

Glyphosate is a commonly used agrochemical active substance co-formulated in glyphosate-based herbicides (GBHs) whose environmental safety is still a subject of debate in the European Union. We evaluated the effects of acute sublethal exposure to glyphosate on rainbow trout by measuring changes in their metabolic and hemato-immunologic functions and their ability to survive a viral challenge. Juvenile fish were exposed for 96 h to 500 µg L-1 of glyphosate through the active substance alone or two GHBs, Roundup Innovert® and Viaglif Jardin®, and fish were then infected with the infectious hematopoietic necrosis virus. Red and white blood cell counts (RBCC and WBCC), as well as several enzymatic activities (citrate synthase, CS; cytochrome-c oxidase, CCO; lactate dehydrogenase, LDH; glucose-6-phosphate dehydrogenase, G6PDH; acetylcholinesterase, AChE), were measured 96 h after chemical contamination (S1), and 96 h post-viral infection (S2). Mortality rates were monitored, and virus titers at the mortality peaks and seropositivity of the survivors were analyzed at 60 days post-viral infection (S3). Cumulative mortalities, viral titers, and seropositivity induced by virus infection were similar among conditions. Hematological analysis revealed significant increases of 30% for RBCC for Roundup at S1, and of 22% for WBCC at S2. No changes were observed in metabolic enzyme activities at S1. At S2, CCO and G6PDH activities were significantly higher than controls in all the chemically contaminated groups (+61 to 62% and +65 to 138%, respectively). LDH and AChE activities were increased for the Viaglif (p = 0.07; +55%) and for glyphosate and Roundup conditions (p < 0.05, +62 to 79%), respectively. Rainbow trout acutely exposed to glyphosate or GBHs presented no major physiological changes. Viral infection revealed disruptions, potentially modulated by co-formulants, of hematological and metabolic parameters, showing that it is essential to consider the stressful natural environment of fish in the chemical assessment.


Assuntos
Herbicidas , Oncorhynchus mykiss , Poluentes Químicos da Água , Animais , Glicina/análogos & derivados , Glicina/toxicidade , Herbicidas/toxicidade , Poluentes Químicos da Água/toxicidade
3.
Sci Total Environ ; 784: 147156, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34088053

RESUMO

While the equilibrium partitioning (EqP) method has been demonstrated to effectively predict the adverse effects of nonionic organic chemicals in sediment on benthic organisms by sediment toxicity tests, only a limited number of studies have been performed both in water-only and whole-sediment toxicity tests using the same species and verified the validity of EqP-based toxicity assessment. To further examine the validity of the EqP method for application in a wide range of hydrophobicity, we conducted sorption/desorption experiments and both water-only and sediment toxicity tests using a popular aquatic crustacean species, Daphnia magna (48 h), and benthic species Hyalella azteca (96 h) for six typical polycyclic aromatic hydrocarbons (PAHs) with three to five rings and an amine derivative: anthracene, phenanthrene, fluoranthene, pyrene, benzo[a]pyrene, dibenzo[a,h]anthracene, and 1-aminopyrene. The linear sorption coefficient was determined and ranged from 2.7 × 102 (phenanthrene) and 1.2 × 104 L/kg (benzo[a]pyrene) highly depending on the hydrophobicity while the aqueous concentrations were stable after 24 h in the desorption test. As result of acute toxicity tests in the water-only exposure system, anthracene and dibenz[a,h]anthracene were found to be nontoxic to both species, while median effect/lethal concentrations (EC50/LC50) were determined as ranging from 0.66 (benzo[a]pyrene) to 330 µg/L (phenanthrene), and from 11 (1-aminopyrene) to 180 µg/L (phenanthrene) for D. magna and H. azteca, respectively. Among these compounds, three PAHs with three, four, and five rings each, and 1-aminopyrene were subjected to sediment-water toxicity tests. In the sediment-water tests, the LC50 of phenanthrene and pyrene was three to six times higher than that of the water-only tests for H. azteca while the EC50 was 1.1 to 2.0 times higher for D. magna. In contrast, the EC50/LC50 of benzo[a]pyrene (BaP) in the sediment-water toxicity test was more than 5 times higher than that in the water-only test for both H. azteca and D. magna. The EC50/LC50 values of 1-aminopyrene were similar in both the sediment-water and the water-only toxicity tests, ranging narrowly from 21 to 28 µg/L and 8.8 to 11 µg/L for D. magna and H. azteca, respectively. The EC50/LC50 based on the body residue (ER50/LR50) was investigated for two of the representative PAHs, pyrene, and BaP. The ER50/LR50 of pyrene in both species was 2.3 and 11 times higher in the water-only toxicity test for D. magna and H. azteca, respectively, while those of BaP in the sediment-water toxicity test were not calculated for the sediment-water toxicity tests, and the highest body concentration in the sediment-water tests was lower than the ER50/LR50 in the water-only toxicity test. Although the experimental results were comparable with the predicted sediment toxicity values based on the EqP method for the selected PAHs in this study, there is a risk of phenanthrene and pyrene being slightly underestimated (1.4-1.9 fold for phenanthrene and 3.7-6.1 fold for pyrene) by the EqP method for H. azteca. These results reaffirm that the bioavailability of poorly water-soluble chemicals is important for sediment toxicity and that the exposure pathway should be further investigated to avoid under- and overestimation via the EqP method.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Daphnia , Sedimentos Geológicos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Água , Poluentes Químicos da Água/toxicidade
4.
Sci Total Environ ; 784: 147167, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34088063

RESUMO

This study aimed to investigate the effect of imidacloprid on structural (invertebrates and primary producers) and functional (organic matter decomposition and physicochemical parameters) characteristics of tropical freshwaters using acute single species and mesocosm studies performed in Ethiopia. The recovery of affected endpoints was also studied by using a mesocosm study period of 21 weeks. Our acute toxicity test showed that Cloeon dipterum (96-h EC50 = 1.5 µg/L) and Caenis horaria (96-h EC50 = 1.9 µg/L) are relatively sensitive arthropods to imidacloprid. The mesocosm experiment evaluated the effects of four applications of imidacloprid with a weekly interval and the results showed that the macroinvertebrate and zooplankton community structure changed significantly due to imidacloprid contamination in mesocosms repeatedly dosed with ≥0.1 and ≥ 0.01 µg/L, respectively (time weighted average concentrations of 112 days (TWA112d) of ≥0.124 and ≥ ≈0.02 µg/L, respectively). The largest responses were found for C. dipterum, C. horaria, Brachionus sp. and Filinia sp. Chlorophyll-a concentrations of periphyton and phytoplankton significantly increased in the ≥0.1 µg/L treatments levels which are indirect effects as a result of the release of grazing pressure. A significant, but quantitatively small, decrease of organic matter decomposition rate was observed in mesocosms treated with repeated doses of 1 µg/L (TWA112d of 2.09 µg/L). No recovery was observed for the macroinvertebrates community during the study period of 21 weeks, but zooplankton recovered after 9 weeks. We observed spatio-temporal related toxicity differences between tropical and temperate aquatic taxa, with tropical taxa generally being more sensitive. This suggests that use of temperate toxicity data for the risk assessment of imidacloprid in tropical region is not recommended.


Assuntos
Inseticidas , Poluentes Químicos da Água , Animais , Ecossistema , Etiópia , Água Doce , Inseticidas/análise , Inseticidas/toxicidade , Neonicotinoides , Nitrocompostos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
5.
Sci Total Environ ; 783: 147154, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34088136

RESUMO

The water bodies are greatly influenced by chemical contamination and global increasing temperature. As an emerging pollutant, microplastics are widely distributed in the freshwater environment, raising concerns regarding their potential toxicity to organisms. Especially for zooplankton filter feeders, many of microplastics are in similar size as their food. Individually, both microplastics and temperature have profound effects on zooplankton populations and their function in ecosystems. However, the strength and direction of their interactive effects are still not clear. Here, we performed a comprehensive biotoxicity assessment providing empirical evidence that the temperature played a key role in shaping the sensitivity of the zooplankter, Daphnia magna, against microplastic toxicity. We found that exposure to microplastics generally caused negative effects on Daphnia individual fitness, such as increased lethality, declined fecundity and reduced population growth rate. This microplastic toxicity was more prominent at 30 °C than at 20 °C, and was rather minor at 15 °C. Moreover, the warming accelerated the ingestion of microplastics, and triggered abnormal ultrastructure of intestinal epithelial cells. In addition, the expression profiling of candidate genes revealed oxidative damage, fecundity impairment and energy retardation by microplastics were amplified with increasing temperature, which may contribute to the enhancement of microplastic toxicity under warming. Given that high temperature fluctuations are becoming more common and difficult to predict, the interactive effects of microplastics and climate warming on Daphnia population dynamics and biomass production may become increasingly aggravated in nature. Collectively, extrapolation for environmental risk assessment studies conducted under different temperature contexts may broaden our knowledge microplastic toxicity on aquatic organism fitness.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Daphnia , Ecossistema , Expressão Gênica , Aptidão Genética , Plásticos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
6.
Sci Total Environ ; 783: 146981, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34088153

RESUMO

Freshwater riverbeds are a major repository of microplastics (MPs) from inland activities. Benthic macroinvertebrates that live in close contact with sediments seem to ingest a considerable amount of such plastic particles. The effects of MPs on life-history traits are relatively well-known, but the suborganismal mechanisms underlying such effects remain unclear. This study addressed the potential effects of low-density polyethylene (LDPE) MPs on Chironomus riparius larvae at cellular and molecular levels. Fourth instar C. riparius larvae were exposed to 0.025 and 2.5 g/kg LDPE of dry sediment (sizes: <32 and 32-45 µm; with irregular shape) under laboratory conditions for 48 h. These short-term exposures to environmental concentrations of LDPE MPs induced changes in the energy reserves (mostly by decreasing carbohydrates and increasing lipids), increased antioxidant and detoxification responses (tGSH, CAT, and GST), and induced increases in the activity of AChE (related to neurotransmission). In addition, at the gene level, exposure to MPs modified mRNA levels of InR, Dis, EcR, Dronc, Met (endocrine system), Def (immune system), PARP, ATM, NLK, and Decay (DNA repair), generating important alterations in the C. riparius development and response to unfavorable situations. This study provides new evidence of the effects of LDPE MPs at the suborganismal level, filling the gap in knowledge regarding the mechanisms underlying the toxicity of MPs and spotlighting gene expression analyses as early indicators of MP toxicity in C. riparius which were confirmed by Integrated biomarker response analyses highlighting the gene expression as sensible and useful endpoints for LPDE pollution in freshwaters. These results, coupled with previous investigations on responses at the organismal level, emphasizes the potential adverse effects of LDPE MPs on C. riparius, which may compromise freshwater benthic communities, considering its ecological role within these habitats.


Assuntos
Chironomidae , Poluentes Químicos da Água , Animais , Larva , Microplásticos , Plásticos/toxicidade , Polietileno/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
7.
Sci Total Environ ; 783: 147076, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34088154

RESUMO

Microplastics (MPs) attract global concern due to their ubiquitous existence in aquatic environments. However, the genotoxic effect of MPs on aquatic organisms in the natural environment remains controversial. Therefore, this meta-analysis was conducted by recompiling 44 individual studies from 12 publications to determine whether MPs could induce genotoxicity in aquatic organisms at environmentally relevant concentrations (≤1 mg/L, median = 0.5 mg/L). Multiple genotoxic endpoints were involved, including the percentage of DNA in tail (TDNA%), tail length (TL), olive tail moment (OTM), and the number of micronuclei (NM), and their increases represented the biologically adverse effects (i.e. genotoxicity). The results showed that all included endpoints tended to increase after exposure to MPs, among which TDNA%, TL and NM were significantly increased by 20%, 32% and 81% compared with the control group, respectively. The overall estimate of all endpoints in the MPs-treated groups was remarkably increased by 24%, with high statistical power and no obvious publication bias, suggesting the evident genotoxicity caused by MPs. In addition, the magnitudes of MPs-induced genotoxicity were independent of selected endpoint, MP composition, morphology, exposure concentration and duration, but closely correlated with particle size, living habitat and tested species. Overall, this work provided a reference for the health risk assessment of MPs in the natural environment, contributing to our understanding the action mode of MPs at environmentally relevant concentrations.


Assuntos
Microplásticos , Poluentes Químicos da Água , Organismos Aquáticos , Dano ao DNA , Plásticos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
8.
Chemosphere ; 276: 130282, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34088109

RESUMO

Sewage effluent ozonation can reduce concentrations of chemical pollutants including pharmaceutical residues. However, the formation of potentially toxic ozonation byproducts (OBPs) is a matter of concern. This study sought to elucidate toxicity mechanisms of ozonated carbamazepine (CBZ), an anti-epileptic drug frequently detected in sewage effluents and surface water, in zebrafish embryos (Danio rerio). Embryos were exposed to ozonated and non-ozonated CBZ from 3 h post-fertilization (hpf) until 144 hpf. Embryotoxicity endpoints (proportion of dead and malformed embryos) were assessed at 24, 48, and 144 hpf. Heart rate was recorded at 48 hpf. Exposure to ozonated CBZ gave rise to cardiovascular-related malformations and reduced heart rate. Moreover, embryo-larvae exposed to ozonated CBZ displayed a lack of swim bladder inflation. Hence, the expression patterns of CBZ target genes involved in cardiovascular and embryonal development were investigated through a stepwise gene co-expression analysis approach. Two co-expression networks and their upstream transcription regulators were identified, offering mechanistic explanations for the observed toxicity phenotypes. The study presents a novel application of gene co-expression analysis elucidating potential toxicity mechanisms of an ozonated pharmaceutical with environmental relevance. The resulting data was used to establish a putative adverse outcome pathway (AOP).


Assuntos
Ozônio , Poluentes Químicos da Água , Animais , Carbamazepina/toxicidade , Ozônio/toxicidade , Esgotos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/genética
9.
Braz J Biol ; 82: e234692, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34105659

RESUMO

The Gravataí River basin, one of the main water sources of the metropolitan region of Porto Alegre, is among the ten most polluted rivers in Brazil. Water quality is monitored only through physico-chemical and microbiological parameters in Brazil, and in this context, considering the importance of the use of biomarkers in complementing the analysis of water, the present study aimed to evaluate the environmental quality of the main affluent of the Gravataí River, Demetrio stream, through physico-chemical, microbiological, and cytogenotoxic criteria, at the stream source (P1), whereas samples P2 and P3 were obtained from the upstream near the area with the highest urban density and the downstream near the meeting point with the Gravataí River, respectively. The results for copper concentration and color classified the Demetrio stream as Class 4 in general, that is, the water is suitable only for navigation and to landscape harmony. The main genotoxic alterations (micronuclei and nuclear buds) were observed in P2, in which were obtained the highest levels of copper, in addition to iron and manganese. Anthropic interventions were observed in P1 and P2; however, due to its low metal concentration, P3, near the Gravataí River, manifested an improvement in environmental quality.


Assuntos
Poluentes Químicos da Água , Qualidade da Água , Brasil , Monitoramento Ambiental , Rios , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
10.
Environ Monit Assess ; 193(7): 414, 2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-34117952

RESUMO

Despite increasing public concern about air and water pollution risks posed by concentrated animal feeding operation areas (CAFOs), there is little information about bioavailability and ecosystem impacts of agrochemicals used to increase productivity. In this study, we investigated the toxicity of wastewaters originating from beef cattle feeding operation on Daphnia pulex. Specifically, we assessed lethal and chronic sublethal exposure effects using various endpoints including survival, oxygen consumption, morphology, reproduction, and swimming behavior. Exposure assessments (acute and chronic) were performed with ten (10) surface water samples collected from on-site retention ponds designated as A, B, C, D, E, F, G, H, I, and R (reference site). Surface water samples were diluted to yield five concentrations (stock, 1 × , 2 × , 3 × , and 4 ×) as treatments and deionized water was used as control. Results showed site-specific and concentration-related effects on toxicity endpoints. Among treatments, significant (p < 0.05) increase in mortality rate (for A, E, F, and H) and decreasing total body length and width (for B, C, D, and G) of D. pulex were observed with increasing wastewater concentration. However, treatments did not have significant effect on swimming behavior (average speed) after exposure to the wastewater samples from all sites except for site E. Evidence from this study suggested that surface waters near beef cattle feed yards affected physiological responses in D. pulex and therefore may similarly affect organisms in the surrounding aquatic ecosystems.


Assuntos
Daphnia , Poluentes Químicos da Água , Agroquímicos , Animais , Bovinos , Ecossistema , Monitoramento Ambiental , Água , Poluentes Químicos da Água/toxicidade
11.
Chemosphere ; 279: 130610, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34134413

RESUMO

Contaminated water with landfill leachate (CWLL) with high salinity and high organic content (total organic carbon (TOC) = 649 mg/L and Chemical Oxygen Demand (COD) = 1175 mg/L) is a toxic and non-biodegradable effluent. The present research aimed to assess the treatment effectiveness of CWLL by electrocoagulation (EC)/oxidant process. The ferrous ions generated during the process were employed as coagulant and catalyst for the activation of different oxidants such as peroxymonosulfate (PMS), peroxydisulfate (PDS), hydrogen peroxide (HP), and percarbonate (PC) to decrease TOC in CWLL. Removal of ammonia, color, phosphorous, and chemical oxygen demand (COD) from CWLL effluent was explored at various processes. EC/HP had the best performance (∼73%) in mineralization of organic pollutants compared to others under the condition of pH 6.8, applied current of 200 mA, oxidant dosage of 6 mM, and time of 80 min. The oxidation priority was to follow this order: EC/HP > EC/PMS > EC/PDS > EC/PC. These processes enhanced the biodegradability of CWLL based on the average oxidation state and biochemical oxygen demand (BOD)/COD ratio. SUVA254 and E2/E3 indices were also investigated on obtained effluents. The phytotoxicity evaluation was carried out based on the germination index, indicating that the electro-activated oxidant was an effective system to reduce the toxicity of polluted waters. EC/HP showed supremacy compared to others in terms of efficiency, cost, and detoxification. Therefore, the electro-activated oxidant system is a good means for removing organic pollutants from real wastewater.


Assuntos
Poluentes Químicos da Água , Análise da Demanda Biológica de Oxigênio , Peróxido de Hidrogênio , Oxirredução , Peróxidos , Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
12.
Chemosphere ; 279: 130612, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34134414

RESUMO

The increasingly common remedial application of nanoscale zero-valent iron (nZVI) to alleviate specific contaminant issues may inadvertently lead to nZVI accumulation in wastewater. This is a potential concern, because the effect of nZVI on the common microbes essential for wastewater biotreatment is not known. This is further complicated when there are many ways available to synthesize nZVI, which may interreact with bacteria differently. Thus, in this study, the different effects of nZVI synthesized by Eucalyptus leaves (EL-nZVI) and a commercially synthesized nZVI on the biodegradation of crystal violet by Burkholderia vietnamiensis C09V (B.V. C09V) was studied. At high dose (1000 mg/L), EL-nZVI and commercial nZVI both significantly inhibited the removal of crystal violet by B.V. C09V, decreasing removal rates by 10.5 and 13.1% respectively. Optical density (OD600) and soluble protein assays indicated that the growth of B.V. C09V improved under low doses (100 mg/L), but remained inhibited under high doses (500 and 1000 mg/L) of both commercial and EL-nZVI. Enzymes were also sensitive to nZVI, where the commercial variant exerted a greater effect on both the activity of lactate dehydrogenase (LDH) and superoxide dismutase (SOD) than EL-nZVI, indicating that EL-nZVI was less toxic than commercial nZVI. LIVE/DEAD staining also showed that the number of apoptotic cells was significantly higher when exposed to commercial nZVI rather than EL-nZVI. Furthermore, scanning electron microscopy (SEM) confirmed that direct contact between nZVI and cells at 1000 mg/L nZVI caused cell membrane disruption. Whereas, at 100 mg/L EL-nZVI, B.V. C09V grew better due to the formation of dense biofilms around the suspended EL-nZVI at a. Fourier transform infrared spectra (FTIR), confirmed an abundance of oxygen-containing functional groups on the surface of EL-nZVI which provided better biocompatibility than commercial nZVI. Overall, while dose was the most significant factor influencing nZVI toxicity, surface composition and morphology was also important. These new findings suggest chemical synthesis of metal nanoparticles should be replaced by biosynthetic routes to maintain viable microbial pollution during wastewater treatment.


Assuntos
Burkholderia , Poluentes Químicos da Água , Purificação da Água , Violeta Genciana , Ferro , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
13.
Chemosphere ; 279: 130623, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34134419

RESUMO

Phytoplankton occupies a key trophic level in aquatic ecosystems. Chemical impacts on these primary producers can disrupt the integrity of an entire ecosystem. Two freshwater (Pseudokirchneriella subcapitata-Ps and Scenedesmus obliquus-S) and three marine (Phaeodactylum tricornutum-P, Isochrysis galbana-I, Tetraselmis suecica-T) microalgae species were exposed to dilutions of four chemicals: nanoparticles (n-TiO2, n-ZnO), amoxicillin (antibiotic), and white musk (personal care fragrance) to determine the half maximal effective concentration (EC50) after 72 h of exposure under standardized and controlled environmental conditions. Cell cultures were exposed to EC50 to determine sublethal effects (72 h) based on biochemical (chlorophylls a, b, c), molecular (changes in outer cell wall structure), and morphological alterations. We report for the first time EC50 values for nanoparticles in not standardized species (S, I and T) and for amoxicillin and white musk in all tested species. Standardized species (Ps and P) were less sensitive than non-standardized in some cases. Fourier-transformed infrared spectroscopy showed a marked spectral alteration (from 10.44% to 90.93%) of treated cultures compared to negative controls; however, principal component analysis disclosed no differences in molecular alteration between the five microalgae species or the two aquatic habitats considered. There was a significant decrease in chlorophylls content in all species exposed to EC50 compared to controls (Kruskal Wallis test; p < 0.05). There was a significant increase in cell-size (Mann-Whitney U test; p < 0.05) in I, P and T exposed to white musk and S exposed to amoxicillin. Findings highlight ecotoxicological risks from new generation pollutants for primary producers in aquatic ecosystems.


Assuntos
Poluentes Ambientais , Microalgas , Nanopartículas , Poluentes Químicos da Água , Amoxicilina/toxicidade , Ecossistema , Ácidos Graxos Monoinsaturados , Água Doce , Fitoplâncton , Poluentes Químicos da Água/toxicidade
14.
Chemosphere ; 279: 130634, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34134424

RESUMO

Sulfamethoxazole (SMX), recognized as emerging pollutant, has been frequently detected in aquatic environment. However, effects induced by SMX and the underneath mechanism on non-target aquatic organisms, marine mussels (Mytilus galloprovincialis), are still largely unknown. In present study, marine mussels were exposed to SMX (nominal concentrations 0.5, 50 and 500 µg/L) for 6 days, followed by 6 days depuration and responses of antioxidant defenses, e.g. superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST), etc., at transcriptional, translational and functional levels were evaluated in two vital tissues, gills and digestive glands. Results showed SMX can be accumulated in mussels while the bio-accumulative ability was low under the experimental condition. A systemic but not completely synchronous antioxidant defense at different levels upon SMX exposure. The transcriptional alteration was more sensitive and had the potential to be used as early warning of SMX induced ecotoxicity. Complementary function of antioxidant enzymes with specific alteration of metabolism related gene (gst) suggested that further researches should focused on SMX metabolism and SMX induced effects simultaneously. Significant tissue-specific antioxidant responses were discovered and gills showed earlier and quicker reacting ability than digestive glands, which was closely related to the functional diversity and different thresholds of xenobiotics allowance.


Assuntos
Mytilus , Poluentes Químicos da Água , Animais , Antibacterianos/toxicidade , Antioxidantes , Biomarcadores , Sulfametoxazol/toxicidade , Poluentes Químicos da Água/toxicidade
15.
Chemosphere ; 279: 130875, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34134435

RESUMO

The environmental persistence of hexachlorobenzene (HCB) is a challenge that promotes studies for efficient treatment alternatives to minimize its environmental impact. Here, we evaluated the HCB removal by electrochemical, biological, and combined approaches. The electrochemical treatment of 4 µM HCB solutions was performed using a synthesized Ti/RuO2-IrO2-TiO2 anode, while the biological treatment using mangrove-isolated bacteria was at 24, 48, and 72 h. The HCB degradability was assessed by analyzing chemical oxygen demand (COD), microbial growth capacity in media supplemented with HCB as the only carbon source, gas chromatography, and ecotoxicity assay after treatments. The synthesized anode showed a high voltammetric charge and catalytic activity, favoring the HCB biodegradability. All bacterial isolates exhibited the ability to metabolize HCB, especially Bacillus sp. and Micrococcus luteus. The HCB degradation efficiency of the combined electrochemical-biological treatment was evidenced by a high COD removal percentage, the non-HCB detection by gas chromatography, and a decrease in ecotoxicity tested with lettuce seeds. The combination of electrochemical pretreatment with microorganism degradation was efficient to remove HCB, thereby opening up prospects for in situ studies of areas contaminated by this recalcitrant compound.


Assuntos
Titânio , Poluentes Químicos da Água , Bactérias , Eletrodos , Hexaclorobenzeno , Lasers , Oxirredução , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
16.
Mar Pollut Bull ; 168: 112369, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33932840

RESUMO

Determining the effects of microplastic (MP) ingestion by marine organisms, especially during the sensitive larval stages, is an important step in understanding wider ecosystem responses. We investigated the ingestion, retention (1-5 µm), and short-term exposure effects (1-4 µm) of spherical MPs by larvae of the sea urchin Pseudechinus huttoni. Larvae ingested MPs in a dose-dependent manner and successfully egested particles after a short retention period. Survival was not significantly affected by exposure to MPs over the 10-day experimental period, however, a teratogenic response in terms of delayed development resulted in an increase of larval arm asymmetry. Additionally, MP exposure resulted in oxidative damage to lipids and proteins in larval body tissue despite a significant upregulation of antioxidant defences. The findings indicate MP exposure may impair cellular function, leading to negative consequences for an organism's fitness and survival.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Ingestão de Alimentos , Ecossistema , Larva , Estresse Oxidativo , Plásticos , Ouriços-do-Mar , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
17.
Mar Pollut Bull ; 168: 112411, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33932844

RESUMO

Nucella lapillus imposex has been monitored in Ria de Aveiro (Portugal) in order to understand the evolution of organotin (OT) pollution after the EU ban on OT-based antifouling systems (OT-AFS). A rapid decrease of imposex occurred, but a countercurrent tendency upsurged recently (2018-2019) with a slight increase of imposex at some sites, instead of a continuous decline towards a complete recovery. In 2018 the vas deferens sequence index ranged between 0.6 and 1.0 across stations and the percentage of females with imposex varied from 63 to 100%. In 2019 these parameters varied between 0.4 and 1.0 and 37-100%, while the concentration of butyltins (TBT, DBT, MBT) in the dogwhelk tissues were < 1 ng Sn g-1 dw. Although N. lapillus imposex levels are low they are indicative of OT pollution. The full recovery of N. lapillus imposex in the future is uncertain and a cause for concern.


Assuntos
Transtornos do Desenvolvimento Sexual , Gastrópodes , Compostos de Trialquitina , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Feminino , Masculino , Portugal , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
18.
Sci Total Environ ; 785: 147317, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33933765

RESUMO

Horticulture has greatly increased in Argentina in recent decades mainly due to increasing greenhouse utilization and agrochemical consumption, thus representing a threat to adjacent water bodies. Riparian wetlands, however, could attenuate agrochemical contamination. The present work therefore compared insecticide concentrations in bottom sediments in addition to sediment toxicity to the amphipod Hyalella curvispina and investigated the macroinvertebrate composition upstream and downstream from a natural wetland in a small stream draining a basin undergoing intense horticultural production. The wetland surface was covered by macrophytes, mainly Thypha sp., and the insecticide concentrations measured downstream from the wetland were significantly lower, at roughly 19% of the upstream values. The growth rates of H. curvispina were significantly higher when exposed to the sediments downstream from the wetland, while the macroinvertebrate-assemblage composition was significantly different upstream and downstream: the snail Pomacea canaliculata was the dominant species upstream while the amphipod H. curvispina was dominant downstream. Pomacea canaliculata is often the dominant species in the regional streams draining agriculture and horticultural basins. Hyalella curvispina is sensitive to pesticide toxicity and is often dominant in streams draining extensive livestock basins and within a biosphere reserve. We conclude that riparian wetlands effectively attenuate horticulture contamination in pampean streams and should therefore be preserved and restored.


Assuntos
Inseticidas , Poluentes Químicos da Água , Agricultura , Animais , Argentina , Monitoramento Ambiental , Horticultura , Inseticidas/análise , Inseticidas/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Áreas Alagadas
19.
Sci Total Environ ; 785: 147284, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33957588

RESUMO

Estrogenic compounds are widely released to surface waters and may cause adverse effects to sensitive aquatic species. Three hormones, estrone, 17ß-estradiol and 17α-ethinylestradiol, are of particular concern as they are bioactive at very low concentrations. Current analytical methods are not all sensitive enough for monitoring these substances in water and do not cover mixture effects. Bioassays could complement chemical analysis since they detect the overall effect of complex mixtures. Here, four chemical mixtures and two hormone mixtures were prepared and tested as reference materials together with two environmental water samples by eight laboratories employing nine in vitro and in vivo bioassays covering different steps involved in the estrogenic response. The reference materials included priority substances under the European Water Framework Directive, hormones and other emerging pollutants. Each substance in the mixture was present at its proposed safety limit concentration (EQS) in the European legislation. The in vitro bioassays detected the estrogenic effect of chemical mixtures even when 17ß-estradiol was not present but differences in responsiveness were observed. LiBERA was the most responsive, followed by LYES. The additive effect of the hormones was captured by ERα-CALUX, MELN, LYES and LiBERA. Particularly, all in vitro bioassays detected the estrogenic effects in environmental water samples (EEQ values in the range of 0.75-304 × EQS), although the concentrations of hormones were below the limit of quantification in analytical measurements. The present study confirms the applicability of reference materials for estrogenic effects' detection through bioassays and indicates possible methodological drawbacks of some of them that may lead to false negative/positive outcomes. The observed difference in responsiveness among bioassays - based on mixture composition - is probably due to biological differences between them, suggesting that panels of bioassays with different characteristics should be applied according to specific environmental pollution conditions.


Assuntos
Disruptores Endócrinos , Poluentes Químicos da Água , Bioensaio , Disruptores Endócrinos/análise , Monitoramento Ambiental , Estrogênios/análise , Estrogênios/toxicidade , Estrona , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
20.
Sci Total Environ ; 786: 147434, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-33964776

RESUMO

Sertraline hydrochloride (Ser-HCl) is an effective and commonly used antidepressant drug, which is also frequently detected in aquatic environments. Our previous research showed that Ser-HCl changes the community composition of aquatic microbiome, but the understanding of the expression of functional pathways in microbial communities is still incomplete; to address this knowledge gap, we used meta-transcriptomics analysis to evaluate the toxicity of Ser-HCl to natural aquatic microbial communities cultured in laboratory microcosms. Meta-transcriptomic results show that a 15-day exposure to 50 µg/L Ser-HCl significantly changed the functional expression activity of aquatic microbial communities. Pathways related to lipid metabolism, energy metabolism, membrane transport function, and genetic information processing in the aquatic microbial community were severely inhibited under Ser-HCl treatment, but metabolism of cofactors and vitamins to alleviate biological toxicity after Ser-HCl exposure was enhanced. Our study thus reveals details of the effects of sertraline on the functioning of aquatic microbiome. Due to the extensive use of Ser-HCl and its strong biological activity, it should not continue to be an overlooked pollutant. Therefore, more attention should be paid to the negative effects of such biologically active drugs on the expression of aquatic microbiome.


Assuntos
Microbiota , Poluentes Químicos da Água , Antidepressivos/toxicidade , Água Doce , Sertralina/toxicidade , Transcriptoma , Poluentes Químicos da Água/toxicidade
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