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1.
Chemosphere ; 261: 128162, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33113662

RESUMO

Microplastics, anthropogenically released into freshwaters, settle in sediments, where they are directly ingested by benthic organisms. However, to the best of our knowledge, fine-scale studies of microplastic ingestion and egestion by nematodes, one of the most abundant meiofaunal taxa, are lacking. We therefore conducted a time series of the ingestion and egestion by adult Caenorhabditis elegans and Pristionchus pacificus of 0.5- and 1.0-µm fluorescent polystyrene (PS) beads along with bacteria. The nematodes were exposed to 107 beads ml-1 in aqueous medium for 5 min-24 h and pumping rates of C. elegans were determined. In the egestion study, PS bead egestion was monitored in nematodes with high microplastic body burdens for 5 min-24 h in microplastic-free medium. Ingested beads were detected already within 5 min and up to 203 ± 15 PS beads (1.0 µm; C. elegans) were found after 30 min. Overall, significantly more 1.0-µm than 0.5-µm PS beads were taken up. The distinct feeding behaviors of the two species influenced their PS bead body burdens. Ingested PS beads were almost completely egested within the first 20-40 min in the presence of sufficient food. In C. elegans, 1.0-µm beads were egested less rapidly than 0.5-µm PS beads. Given the rapid ingestion and egestion of the beads, our study demonstrates that the actual amount of ingested and egested microplastics by nematodes in the environment may be several times higher than the microplastic body burdens may imply. However, spherical PS beads did not bioconcentrate in nematodes.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Microplásticos/farmacocinética , Poluentes Químicos da Água/farmacocinética , Animais , Bactérias , Exposição Dietética , Ingestão de Alimentos , Comportamento Alimentar , Água Doce , Microplásticos/análise , Poliestirenos/análise , Poliestirenos/farmacocinética , Poluentes Químicos da Água/análise
2.
Mar Environ Res ; 160: 104987, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32907725

RESUMO

Ocean acidification alters physiology, acid-base balance and metabolic activity in marine animals. Near future elevated pCO2 conditions could be expected to influence the bioaccumulation of metals, feeding rate and immune parameters in marine mussels. To better understand such impairments, a series of laboratory-controlled experiment was conducted by using a model marine mussel, Mytilus galloprovincialis. The mussels were exposed to three pH conditions according to the projected CO2 emissions in the near future (one ambient: 8.10 and two reduced: 7.80 and 7.50). At first, the bioconcentration of Ag and Cd was studied in both juvenile (2.5 cm) and adult (5.1 cm) mussels by using a highly sensitive radiotracer method (110mAg and 109Cd). The uptake and depuration kinetics were followed 21 and 30 days, respectively. The biokinetic experiments demonstrated that the effect of ocean acidification on bioconcentration was metal-specific and size-specific. The uptake, depuration and tissue distribution of 110mAg were not affected by elevated pCO2 in both juvenile and adult mussels, whereas 109Cd uptake significantly increased with decreasing pH in juveniles but not in adults. Regardless of pH, 110mAg accumulated more efficiently in juvenile mussels than adult mussels. After executing the biokinetic experiment, the perturbation was sustained by using the same mussels and the same experimental set-up, which enabled us to determine filtration rate, haemocyte viability, lysosomal membrane stability, circulating cell-free nucleic acids (ccf-NAs) and protein (ccf-protein) levels. The filtration rate and haemocyte viability gradually decreased by increasing pCO2 level, whereas the lysosomal membrane stability, ccf-NAs, and ccf-protein levels remained unchanged in the mussels exposed to elevated pCO2 for eighty-two days. This study suggests that acidified seawater partially shift metal bioaccumulation, physiological and cellular parameters in the mussel Mytilus galloprovincialis.


Assuntos
Dióxido de Carbono , Metais , Mytilus , Poluentes Químicos da Água , Animais , Bioacumulação , Concentração de Íons de Hidrogênio , Metais/farmacocinética , Mytilus/química , Água do Mar , Poluentes Químicos da Água/farmacocinética
3.
Mar Environ Res ; 160: 104992, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32907729

RESUMO

Livers from dab (Limanda limanda), plaice (Pleuronectes platessa) and flounder (Platichthys flesus) sampled from the Baltic Sea were used to determine the interaction of flatfish CYP1A enzymes with 2,4,6-trinitrotoluene (TNT) in vitro. Competitive inhibition of 7-ethoxyresorufin-O-deethylase (EROD) and 7-methoxyresorufin-O-deethylase (MROD) could be demonstrated for all three flatfish species. The highest inhibition of CYP1A activities was measured in liver samples of flounder resulting in a half maximal inhibitory concentration (IC50) of 28.1 µM TNT. Due to their lower inhibition (EROD IC50 65.2 µM TNT, MROD IC50 40.3 µM TNT), dab liver samples were used to conduct in vitro metabolization experiments with TNT. The metabolization of TNT in fish was investigated with post-mitochondrial fractions (PMF) of dab liver as a model system after adding different cofactors. Rapid and time-dependent enzymatic degradation of TNT was observed. The concentrations of 4-amino-2,6-dinitrotoluene and 2-amino-4,6-dinitrotoluene increased in the samples over time. Additionally, 2,2,6,6-tetranitro-4,4-azoxytoluene was detected in one sample. The results of this study indicate that in vitro experiments are useful to investigate the xenobiotic metabolism of fish under controlled conditions prior to field studies. The metabolites found can serve as target compounds for marine monitoring of TNT contamination in munition dumpsites.


Assuntos
Linguado , Trinitrotolueno , Poluentes Químicos da Água , Animais , Citocromo P-450 CYP1A1 , Fígado , Trinitrotolueno/farmacocinética , Trinitrotolueno/toxicidade , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade
4.
PLoS One ; 15(8): e0234166, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797098

RESUMO

Response to simultaneous stressors is an important facet of plant ecology and land management. In a greenhouse trial, we studied how eight plant species responded to single and combined effects of three soil concentrations of the phytotoxic munitions constituent RDX and two levels of water-resourcing. In an outdoor trial, we studied the effects of high RDX soil concentration and two levels of water-resourcing in three plant species. Multiple endpoints related to RDX fate, plant health, and plant survival were evaluated in both trials. Starting RDX concentration was the most frequent factor influencing all endpoints. Water-resourcing also had significant impacts, but in fewer cases. For most endpoints, significant interaction effects between RDX concentration and water-resourcing were observed for some species and treatments. Main and interaction effects were typically variable (significant in one treatment, but not in another; associated with increasing endpoint values for one treatment and/or with decreasing endpoint values in another). This complexity has implications for understanding how RDX and water-availability combine to impact plants, as well as for applications like phytoremediation. As an additional product of these greenhouse and outdoor trials, three plants native or naturalized within the southeastern United States were identified as promising species for further study as in situ phytoremediation resources. Plumbago auriculata exhibited relatively strong and markedly consistent among-treatment mean proportional reductions in soil RDX concentrations (112% and 2.5% of the means of corresponding values observed within other species). Likewise, across all treatments, Salvia coccinea exhibited distinctively low variance in mean leaf chlorophyll content index levels (6.5% of the means of corresponding values observed within other species). Both species also exhibited mean wilting and chlorosis levels that were 66% and 35%, and 67% and 84%, of corresponding values observed in all other plants, respectively. Ruellia caroliniensis exhibited at least 43% higher mean survival across all treatments than any other test species in outdoor trials, despite exhibiting similar RDX uptake and bioconcentration levels.


Assuntos
Substâncias Explosivas/toxicidade , Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Triazinas/toxicidade , Acanthaceae/efeitos dos fármacos , Acanthaceae/crescimento & desenvolvimento , Acanthaceae/fisiologia , Biodegradação Ambiental , Substâncias Explosivas/administração & dosagem , Substâncias Explosivas/farmacocinética , Instalações Militares , Desenvolvimento Vegetal/efeitos dos fármacos , Fenômenos Fisiológicos Vegetais/efeitos dos fármacos , Plumbaginaceae/efeitos dos fármacos , Plumbaginaceae/crescimento & desenvolvimento , Plumbaginaceae/fisiologia , Salvia/efeitos dos fármacos , Salvia/crescimento & desenvolvimento , Salvia/fisiologia , Poluentes do Solo/administração & dosagem , Poluentes do Solo/farmacocinética , Sudeste dos Estados Unidos , Estresse Fisiológico/efeitos dos fármacos , Triazinas/administração & dosagem , Poluentes Químicos da Água/administração & dosagem , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade , Recursos Hídricos
5.
Toxicology ; 441: 152529, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32590024

RESUMO

1,1,2,2-tetrafluoro-2-[1,1,1,2,3,3-hexafluoro-3-(1,1,2,2-tetrafluoroethoxy)propan-2-yl]oxyethane-1-sulfonic acid (PFESA-BP2) was first detected in 2012 in the Cape Fear River downstream of an industrial manufacturing facility. It was later detected in the finished drinking water of municipalities using the Cape Fear River for their water supply. No toxicology data exist for this contaminant despite known human exposure. To address this data gap, mice were dosed with PFESA-BP2 at 0, 0.04, 0.4, 3, and 6 mg/kg-day for 7 days by oral gavage. As an investigative study, the final dose groups evolved from an original dose of 3 mg/kg which produced liver enlargement and elevated liver enzymes. The dose range was extended to explore a no effect level. PFESA-BP2 was detected in the sera and liver of all treated mice. Treatment with PFESA-BP2 significantly increased the size of the liver for all mice at 3 and 6 mg/kg-day. At the 6 mg/kg-day dose, the liver more than doubled in size compared to the control group. Male mice treated with 3 and 6 mg/kg-day and females treated with 6 mg/kg-day demonstrated significantly elevated serum markers of liver injury including alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), and liver/body weight percent. The percent of PFESA-BP2 in serum relative to the amount administered was similar in male and female mice, ranged from 9 to 13 %, and was not related to dose. The percent accumulation in the liver of the mice varied by sex (higher in males), ranged from 30 to 65 %, and correlated positively with increasing dose level.


Assuntos
Hidrocarbonetos Fluorados/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Feminino , Hidrocarbonetos Fluorados/sangue , Hidrocarbonetos Fluorados/farmacologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Tamanho do Órgão/efeitos dos fármacos , Poluentes Químicos da Água/sangue , Poluentes Químicos da Água/farmacocinética
6.
Ecotoxicol Environ Saf ; 201: 110861, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32544748

RESUMO

Marine biota have been co-challenged with ocean warming and mercury (Hg) pollution over many generations because of human activities; however, the molecular mechanisms to explain their combined effects are not well understood. In this study, a marine planktonic copepod Pseudodiaptomus annandalei was acutely exposed to different temperature (22 and 25 °C) and Hg (0 and 118 µg/L) treatments in a 24-h cross-factored experiment. Hg accumulation and its subcellular fractions were determined in the copepods after exposure. The expression of the genes of superoxide dismutase (SOD), glutathione peroxidase (GPx), metallothionein1 (mt1), heat shock protein 70 (hsp70), hsp90, hexokinase (hk), and pyruvate kinase (pk) was also analyzed. Both the Hg treatment alone and the combined exposure of warmer temperature plus Hg pollution remarkably facilitated Hg bioaccumulation in the exposed copepods. Compared with the Hg treatment alone, the combined exposure increased total Hg accumulation and also the amount of Hg stored in the metal-sensitive fractions (MSF), suggesting elevated Hg toxicity in P. annandalei under a warmer environment, given that the MSF is directly related to metal toxicity. The warmer temperature significantly up-regulated the mRNA levels of mt1, hsp70, hsp90, and hk, indicating the copepods suffered from thermal stress. With exposure to Hg, the mRNA level of SOD increased strikingly but the transcript levels of hsp90, hk, and pk decreased significantly, indicating that Hg induced toxic events (e.g., oxidative damage and energy depletion). Particularly, in contrast to the Hg treatment alone, the combined exposure significantly down-regulated the mRNA levels of SOD and GPx but up-regulated the mRNA levels of mt1, hsp70, hsp90, hk, and pk. Collectively, the results of this study indicate that ocean warming will potentially boost Hg toxicity in the marine copepod P. annandalei, which is information that will increase the accuracy of the projections of marine ecosystem responses to the joint effects of climate change stressors and metal pollution on the future ocean.


Assuntos
Copépodes/efeitos dos fármacos , Temperatura Alta , Mercúrio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Copépodes/genética , Copépodes/metabolismo , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Hexoquinase/genética , Hexoquinase/metabolismo , Mercúrio/farmacocinética , Metalotioneína/genética , Metalotioneína/metabolismo , Piruvato Quinase/genética , Piruvato Quinase/metabolismo , RNA Mensageiro/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Regulação para Cima , Poluentes Químicos da Água/farmacocinética
7.
Environ Geochem Health ; 42(11): 3765-3778, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32594418

RESUMO

The heavy metal contamination of the aquatic ecosystem is still prevalent even after reduction of the external anthropogenic inputs of the metals. The release of labile heavy metals from the sediments into the water is a potential risk, responsible for the contamination of the aquatic system. Herein, samples of sedimentary column cores were collected in Nansi Lake, and the distribution profiles of the labile and soluble metals (Cd, Cu, Ni, Pb, and Zn) were obtained by the diffusive gradient in thin films (DGT) and the high-resolution dialysis (HR-peeper) technique. Furthermore, the mobility, bioavailability and release risk of the heavy metals were assessed using the results of geochemical sequential extraction, DGT as well as the DGT-induced fluxes in sediments (DIFS) model. The results showed that the profile characteristics of the DGT-labile and soluble heavy metals showed irregular distribution in the sediment cores and Cd, Pb, Zn had an obvious positive correlation with Fe/Mn (p < 0.05). Ni, Cu, and Zn existed primarily in the residual fraction (accounting for 58-76%), while Cd and Pb existed in the reducible fraction (accounting for 50-67%). The Cd and Ni (0.027-0.185) had higher mobility coefficients compared with Pb, Cu, and Zn (0-0.011), and positive diffusive fluxes also proved that Cd and Ni were easy to be released from the sediments. In addition, the R values of five metals (0.18-0.85) ranged between Rdiff to 0.95, indicating that all the metals had partially sustained case from the sediments solid phase. Based on the DIFS model, the five metals had weak mobility from the sediment to pore water, but the release risks in the Nansi Lake should also be of concern, especially for the highly mobile Cd and Ni in the Dushan Lake.


Assuntos
Sedimentos Geológicos/química , Lagos/química , Metais Pesados/análise , Poluentes Químicos da Água/análise , Disponibilidade Biológica , China , Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Lagos/análise , Metais Pesados/química , Metais Pesados/farmacocinética , Modelos Teóricos , Poluentes Químicos da Água/química , Poluentes Químicos da Água/farmacocinética
8.
Ecotoxicol Environ Saf ; 196: 110549, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32251953

RESUMO

Chemicals used to assure agricultural production and the feasibility of planting sites often end up in bodies of water used for crop irrigation. In a pot study, we investigated the consequences associated with the irrigation of maize with water contaminated by ciprofloxacin (Cipro; 0, 0.2, 0.8, 1.4 and 2.0 µg l-1) and/or glyphosate (0, 5, 25 and 50 mg l-1) on yields and food safety. Glyphosate in concentrations ≥25 mg l-1 prevented plant establishment, regardless of Cipro presence. Evaluations made at the V5 stage of plants reveal that Cipro concentrations ≥0.8 µg l-1 and glyphosate decreased photosynthesis and induced changes in leaf anatomy and stem biophysical properties that may contribute to decreased kernel yields. When those chemicals were applied together, kernel yield reductions were accentuated, evidencing their interactive effects. Irrigation with contaminated water resulted in accumulations of Cipro and glyphosate (as well as its metabolite, aminomethylphosphonic acid) in plant tissues. Accumulation of these chemicals in plant tissues such as leaves and kernels is a problem, since they are used to feed animals and humans. Moreover, these chemicals are of potential toxicological concern, principally due to residue accumulations in the food chain. Specially, the antibiotic residue accumulations in maize tissues can assist the induction of antibiotic resistance in dangerous bacteria. Therefore, we point out the urgency of monitoring the quality of water used for crop irrigation to avoid economic and food-quality losses.


Assuntos
Antibacterianos/toxicidade , Ciprofloxacino/toxicidade , Glicina/análogos & derivados , Poluentes Químicos da Água/toxicidade , Zea mays/efeitos dos fármacos , Irrigação Agrícola , Animais , Antibacterianos/farmacocinética , Ciprofloxacino/farmacocinética , Produtos Agrícolas/anatomia & histologia , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/economia , Inocuidade dos Alimentos , Glicina/farmacocinética , Glicina/toxicidade , Humanos , Fotossíntese/efeitos dos fármacos , Folhas de Planta/anatomia & histologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Poluentes Químicos da Água/farmacocinética , Zea mays/anatomia & histologia , Zea mays/metabolismo
9.
Ecotoxicol Environ Saf ; 197: 110626, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32339959

RESUMO

The objective of this study was to evaluate the tissue distributions of antibiotics in the fish, the bioaccumulation and trophic transfer in freshwater food web in Taihu Lake, a large shallow freshwater lake. Twenty four out of 41 antibiotics were detected in the biotas of the food web; and antibiotic concentrations followed the orders: fish plasma ~ fish muscle < fish liver ~ fish bile and fish < invertebrates ~ plankton. Antibiotic concentrations in the liver of piscivores were higher than those in omnivores and planktivores. Most bioaccumulation factors (BAFs) of sulfonamides (SAs), macrolides (MLs), ionophores (IPs) and lincomycin (LIN) were less than 2000 L/kg, indicating low bioaccumulation ability of these compounds in fish. Fluoroquinolones (FQs) were frequently detected in fish liver, invertebrates and plankton with much of BAFs great than 5000 L/kg, indicating that FQs have the potential of bioaccumulation in fish. Relationship analysis between BAFs and physicochemical properties of antibiotics showed that the bioaccumulation of antibiotics in the biota was related with their adsorption ability. Generally, the antibiotics in the food web of Lake Taihu including plankton, invertebrates and fish showed trophic dilution. The normalized estimated daily intake (EDI) values are less than the acceptable daily intake (ADI) values, and then hazard quotients were much less than 1. This result suggests the consumption of fish, crab and shrimp in Lake Taihu would probably not pose direct detrimental effects on humans.


Assuntos
Antibacterianos/análise , Organismos Aquáticos/metabolismo , Monitoramento Ambiental/métodos , Lagos/química , Poluentes Químicos da Água/análise , Animais , Antibacterianos/farmacocinética , Organismos Aquáticos/efeitos dos fármacos , China , Crustáceos/metabolismo , Peixes/metabolismo , Cadeia Alimentar , Humanos , Plâncton/metabolismo , Medição de Risco , Poluentes Químicos da Água/farmacocinética
10.
Ecotoxicol Environ Saf ; 195: 110470, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32199218

RESUMO

Natural aquatic colloids play an important role in the migration, transformation of pollutants in the environment, but their potential effects are often ignored in ecotoxicology research. In this study, diclofenac (DCF) was selected as a typical drug to study the effects of natural colloids on the bioaccumulation and biotoxicity in juvenile zebrafish (Danio rerio) exposed to an environmentally relevant concentration (1 µg/L) and a high concentration (100 µg/L) of DCF. The results showed that the presence of colloids accelerated and enhanced the accumulation of DCF in zebrafish muscle and viscera, and the effects are greater at the environmentally relevant concentration of DCF. However, the colloids enhanced the burden in the head in the environmentally relevant concentration group, but reduced it in the high concentration group. This observation may be related to the occurrence of variations in the contribution of the adsorption forms of DCF and the colloids depending on different DCF concentrations. At the same time, the presence of colloids can significantly induce AChE activity of DCF in the brain and alter swimming activity and shoaling behaviour of the individuals, however no significant effects on the attack and shock behaviour were observed. These findings indicate that the combination of natural colloids and pollutants may change with pollutant concentrations, thereby altering the bioaccumulation and biological effects in aquatic organisms.


Assuntos
Diclofenaco/toxicidade , Poluentes Químicos da Água/toxicidade , Adsorção , Animais , Bioacumulação , Coloides , Diclofenaco/farmacocinética , Poluentes Químicos da Água/farmacocinética , Peixe-Zebra/metabolismo , Peixe-Zebra/fisiologia
11.
Ecotoxicol Environ Saf ; 193: 110365, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32114244

RESUMO

The biochemical responses of Bellamya aeruginosa as a dominant and widespread freshwater gastropod throughout China to waterborne cadmium (Cd) were investigated to explore the impacts of exposure concentration and duration in this potential sentinel species. After the 7 days' test of dosage-mortality relationship, gastropods were exposed for either 7 days at the LC50 (1.7 mg/L), the LC10 (0.7 mg/L) and 0.02 mg/L Cd, or 28 days at 0.02 mg/L Cd. A suite of biochemical indicators including metallothionein-like protein (MTLP), reduced glutathione (GSH), catalase (CAT), contents of tissue metal (Cd, Fe, Mn, Cu, Zn), and the compartments of these metals bound to MTLP were examined. The treatment of 0.02 mg/L Cd led to the increase of Cd bound to MTLP (Cd-MTLP) levels, the decrease of GSH content, and the upregulation of CAT activity, but no induction of MTLP, indicating that the intrinsic MTLP and GSH worked together for the detoxification of Cd at the low exposure. When the exposure concentration increased, GSH was depleted severely and synthesis of MTLP was triggered, leading to a strong and significant relationship between MTLP level and Cd accumulation. At the lethal concentrations (1.7 mg/L), both MTLP induction and CAT activity were inhibited while the proportion of Cd-MTLP to total Cd were increased, suggesting more intrinsic MTLP were utilized to sequester free Cd ions. Therefore, the content of Cd-MTLP in digestive glands of B. aeruginosa was recommended as a reliable biomarker for Cd contamination.


Assuntos
Cádmio/toxicidade , Gastrópodes/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Cádmio/farmacocinética , Catalase/metabolismo , Biomarcadores Ambientais , Água Doce , Gastrópodes/metabolismo , Glutationa/metabolismo , Metalotioneína/metabolismo , Metais/metabolismo , Poluentes Químicos da Água/farmacocinética
12.
Ecotoxicol Environ Saf ; 192: 110289, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32061990

RESUMO

Comparatively limited knowledge is known about the accumulation processes of tributyltin (TBT) and triphenyltin (TPT) in fish and aquatic plant in the freshwater environment, which has hindered a full understanding of their bioaccumulation potential and ecological risks. In the present study, sorption of TBT and TPT on dead biota of both carp and C. demersum from water via the batch equilibrium technique as well as uptake of them on live biota of both carp and C. demersum from water at a static and a dynamic kinetics tests were investigated, respectively. Both TBT and TPT exhibit a high affinity in carps and C. demersum. And C. demersum has a faster metabolism either for TBT or TPT than carp. The apparent uptake values (Cbio = 1904-8831 µg/kg) or bioconcentration factor (BCF = 3333-44000 L/kg) were one or two orders of magnitude higher than that of estimated by a simple sorption (405-472 µg/kg) or lipid model (74.5-149.6 µg/kg) for carp, indicating the uptake of TBT and TPT did not only depend on lipids but also oxygen ligands or macromolecules such as amino acids and proteins of the living organism. In contrast, the apparent Cbio values (149.1-926.4 µg/kg) of both TBT and TPT were lower than that of estimated by sorption model (1341-1902 µg/kg) for C. demersum, which were due to the rapid metabolic rate of them, especially for TBT. But no relation was observed between TBT and TPT concentrations and lipid contents in C. demersum.


Assuntos
Compostos Orgânicos de Estanho/farmacocinética , Compostos de Trialquitina/farmacocinética , Poluentes Químicos da Água/farmacocinética , Animais , Carpas/metabolismo , Cinética , Magnoliopsida/metabolismo
13.
Ecotoxicol Environ Saf ; 193: 110336, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32092581

RESUMO

Aquatic environments contaminated by lead (Pb) are a problem in many regions of world. Since Pb has high toxicity, the identification of species for phytoremediation is important for the recovery of these areas. Thus, the phytoremediation potential of Panicum aquaticum Poir. (Poaceae) was evaluated. The anatomical and physiological responses of P. aquaticum were assessed under different concentrations of Pb [0.0, 0.5, 1.0, 2.0, 4.0, and 8.0 mM of Pb(NO3)2]. Plant growth, anatomy of roots and leaves, root uptake, root to shoot translocation, and the concentration and accumulation of Pb in organs were analyzed. Regarding leaf anatomy, Pb treatment led to changes in epidermis thickness, stomatal density, stomatal diameter, and sclerenchymal area. Endoderm thickness was increased at the highest concentrations of Pb, which may be related to reduced translocation and shoot accumulation. The roots of P. aquaticum presented increased absorption (2279 µg g-1 DW-1 of Pb). In conclusion, P. aquaticum was found to have potential for the phytoremediation of areas contaminated with Pb.


Assuntos
Chumbo/farmacocinética , Panicum/metabolismo , Poluentes Químicos da Água/farmacocinética , Biodegradação Ambiental , Chumbo/toxicidade , Panicum/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Poluentes Químicos da Água/toxicidade
14.
Ecotoxicol Environ Saf ; 191: 110173, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31935558

RESUMO

In aquatic organisms, dietary exposure to nanomaterials is not only one of the important uptake pathways, but it is also one method to assess the transmission risk of the food chain. To address this concern, we quantitatively investigated the accumulation and depuration of fullerenols in the tissues of zebrafish after exposure to fullerenols-contaminated Daphnia magna. After exposure to 13C-labelled fullerenol solution at a concentration of 2.5 mg/L for 72 h, the steady state concentration of fullerenols in D. magna was 31.20 ± 1.59 mg/g dry weight. During the 28 d uptake period for zebrafish, fullerenols in the tissues increased in a tissue- and day-dependent manner, and the major target tissues of fullerenols were the intestines and liver, followed by the gill, muscle, and brain. The kinetic parameters of uptake and depuration were also quantitatively analyzed. After depuration for 15 d, a certain amount of residual fullerenols remained in the tissues, especially the brain, where approximately 64 d may be needed to achieve 90% of the cumulative concentration depuration. The calculated distribution-based trophic transfer factors (TTFd values) (from 0.26 to 0.49) indicated that the tissue biomagnification of fullerenols by zebrafish through dietary exposure may not occur. Transmission electron microscopy (TEM) confirmed the presence of fullerenols in D. magna and the tissues of zebrafish. Our research data are essential for thoroughly understanding of the fate of nanoparticles through the dietary exposure pathway and directing future tissue bioeffect studies regarding target tissues for further research.


Assuntos
Exposição Dietética/análise , Fulerenos/farmacocinética , Nanopartículas/metabolismo , Poluentes Químicos da Água/farmacocinética , Peixe-Zebra/metabolismo , Animais , Bioacumulação , Daphnia/metabolismo , Cadeia Alimentar , Distribuição Tecidual
15.
Ecotoxicol Environ Saf ; 191: 110186, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31954922

RESUMO

A three-dimensional quantitative structure-activity relationship (3D-QSAR) model was established based on molecular structures and docking scores (representing the biodegradability); the scores were obtained for 23 fluoroquinolones (FQs) and the oxidoreductase (PDB ID: 1YZP) of Phanerochaete chrysosporium in the aerobic process of municipal wastewater treatment plants. In the Comparative Molecular Field Analysis (CoMFA) model, q2 was 0.516 and r2pred was 0.727, which showed that the model was reliable and robust. The modification information obtained by the contour maps showed that introducing electronegative, bulky or electropositive groups at different active sites could increase the biodegradability of fluoroquinolone derivatives. Using levofloxacin (LEV) as a modified molecule, 35 fluoroquinolone derivatives with higher biodegradability than LEV were designed. After the evaluation of genotoxicity, bioconcentration and photodegradation, Derivative-15, with higher biodegradability (increased by 27.85%), higher genotoxicity, higher photodegradation and lower bioconcentration, was identified as the most environmentally friendly fluoroquinolone derivative. The 2D-QSAR model of FQ biodegradability was established through the quantization parameters, and q+ was identified as the main parameter affecting the biodegradability of FQs through sensitivity analysis. In addition, the docking results of LEV and Derivative-15 with the oxidoreductase in P. chrysosporium showed that the electrostatic field force between Derivative-15 and the amino acid residues promoted the binding of the donor to the receptor protein, thereby increasing the biodegradability of Derivative-15. Additionally, molecular dynamics simulations revealed that the enhancement of the electrostatic field force with Derivative-15 could promote the binding of the ligand to the receptor, which was basically consistent with the conclusion of molecular docking. Finally, the three microbial degradation pathways of LEV and Derivative-15 were also proposed. The total energy barrier value of the pathway with the lowest total energy barrier of biodegradation was reduced by 32.07%, which was basically consistent with the enhancement of biodegradability of Derivative-15.


Assuntos
Fluoroquinolonas/química , Modelos Moleculares , Poluentes Químicos da Água/química , Basidiomycota/enzimologia , Biodegradação Ambiental , Fluoroquinolonas/farmacocinética , Fluoroquinolonas/toxicidade , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Oxirredutases/química , Relação Quantitativa Estrutura-Atividade , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade
16.
Arch Environ Contam Toxicol ; 78(2): 216-229, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31897536

RESUMO

The evaluation of bioconcentration, toxicity, and hazard (BTH) of persistent lipophilic organic compounds (LOCs) are generally performed as separate rather than integrated assessments. There are adequate data sets in the literature for chlorobenzenes (CBs) consisting of (a) concentrations in aquatic biota (CB) and water (Cw) in the natural environment, (b) laboratory-derived bioconcentration factors (KB) and field concentration ratios (CR), the field equivalent factor of KB, (c) measured internal lethal concentrations (ILC50) and model estimated ILC50 calculated from KB and lethal concentrations (LC50), and (d) calculated hazard quotients in aquatic biota (HQB) and in water (HQW). However, there have been no integrated studies of those parameter values based on the respective lipid-based parameters (CBL, KBL, CRL, ILC50L, HQBL) performed. This study utilized the lipid-based parameters for CBs; a group of widely occuring, bioaccumulative, and toxic LOCs, and integrated those parameters into a bioconcentration-toxicity-hazard (BTHL) index. The values of the parameters were obtained from selected literature with known lipid contents of the aquatic biota. The results showed that the laboratory derived bioconcentration factors, KBLs, were comparable to the corresponding field based factors, CRLs, and the measured internal lethal concentrations, ILC50L, showed comparable values with the estimated ones. The integrated BTHL index was less than an order of magnitude or moderately acceptable for the assessment of variability, uncertainty, and predictive power of the index. This integrated assessment can be used to support decision making dealing with CBs in specific and LOCs in general, both in regional and global aquatic environments.


Assuntos
Clorobenzenos/análise , Clorobenzenos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Animais , Bioacumulação , Clorobenzenos/farmacocinética , Ecotoxicologia/métodos , Dose Letal Mediana , Metabolismo dos Lipídeos/efeitos dos fármacos , Poluentes Químicos da Água/farmacocinética
17.
Environ Geochem Health ; 42(2): 531-543, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31376046

RESUMO

This study aimed to assess the effects of major ecotoxic heavy metals accumulated in the Buriganga and Turag River systems on the liver, kidney, intestine, and muscle of common edible fish species Puntius ticto, Heteropneustes fossilis, and Channa punctatus and determine the associated health risks. K was the predominant and reported as a major element. A large concentration of Zn was detected in diverse organs of the three edible fishes compared with other metals. Overall, trace metal analysis indicated that all organs (especially the liver and kidney) were under extreme threat because the maximum permissible limit set by different international health organizations was exceeded. The target hazard quotient and target cancer risk due to the trace metal content were the largest for P. ticto. Thus, excessive intake of P. ticto from the rivers Buriganga and Turag could result in chronic risks associated with long-term exposure to contaminants. Histopathological investigations revealed the first detectable indicators of infection and findings of long-term injury in cells, tissues, and organs. Histopathological changes in various tissue structures of fish functioned as key pointers of connection to pollutants, and definite infections and lesion types were established based on biotic pointers of toxic/carcinogenic effects. The analysis of histopathological alterations is a controlling integrative device used to assess pollutants in the environment.


Assuntos
Peixes , Metais Pesados/análise , Medição de Risco/métodos , Rios/química , Poluentes Químicos da Água/análise , Animais , Bangladesh , Peixes-Gato , Monitoramento Ambiental , Produtos Pesqueiros/análise , Contaminação de Alimentos , Humanos , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Metais Pesados/farmacocinética , Metais Pesados/toxicidade , Músculos/química , Músculos/efeitos dos fármacos , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade
18.
Arch Environ Contam Toxicol ; 78(2): 267-283, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31760438

RESUMO

Few published studies have examined whether the elevated concentrations of the nonessential toxic metal mercury (Hg) often observed in shark muscle also occur in the shark brain or whether Hg accumulation affects shark neurophysiology. Therefore, this study examined accumulation and distribution of Hg in the shark brain, as well as effects of Hg on oxidative stress in the shark central nervous system, with particular focus on the Atlantic sharpnose shark (Rhizoprionodon terraenovae). Sharks were collected along the southeastern U.S. coast throughout most of this species' U.S. geographical range. Total Hg (THg) concentrations were measured in and compared between shark muscle and brain, whereas known biomarkers of Hg-induced neurological effects, including glutathione depletion, lipid peroxidation, and concentrations of a protein marker of glial cell damage (S100b), were measured in shark cerebrospinal fluid. Brain THg concentrations were correlated with muscle THg levels but were significantly lower and did not exceed most published thresholds for neurological effects, suggesting limited potential for detrimental responses. Biomarker concentrations supported this premise, because these data were not correlated with brain THg levels. Hg speciation also was examined. Unlike muscle, methylmercury (MeHg) did not comprise a high percentage of THg in the brain, suggesting that differential uptake or loss of organic and inorganic Hg and/or demethylation of MeHg may occur in this organ. Although Hg accumulation in the shark brain generally fell below toxicity thresholds, higher THg levels were measured in the shark forebrain compared with the midbrain and hindbrain. Therefore, there is potential for selective effects on certain aspects of shark neurophysiology if brain Hg accumulation is increased.


Assuntos
Encéfalo/efeitos dos fármacos , Mercúrio/farmacocinética , Mercúrio/toxicidade , Tubarões/metabolismo , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade , Animais , Oceano Atlântico , Bioacumulação , Encéfalo/metabolismo , Biomarcadores Ambientais/efeitos dos fármacos , Monitoramento Ambiental , Feminino , Masculino , Mercúrio/análise , Compostos de Metilmercúrio/análise , Compostos de Metilmercúrio/farmacocinética , Músculos/efeitos dos fármacos , Músculos/metabolismo , Sudeste dos Estados Unidos , Poluentes Químicos da Água/análise
19.
Arch Environ Contam Toxicol ; 78(2): 254-266, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31650202

RESUMO

Uranium is the heaviest naturally occurring element on Earth. Uranium mining may result in ground and surface water contamination with potential bioaccumulation and dispersion by aquatic invertebrates with aerial stages. We investigated the effects of uranium contamination at community level in terms of abundance, richness, the composition of invertebrate communities, and functional traits. We also investigated uranium mobility across aquatic food webs and its transfer to land via the emergence of aquatic insects. We sampled water, sediment, biofilm, macrophytes, aquatic invertebrates, adult insects, and spiders in the riparian zone across sites with a gradient of uranium concentrations in stream water (from 2.1 to 4.7 µg L-1) and sediments (from 10.4 to 41.8 µg g-1). Macroinvertebrate assemblages differed between sites with a higher diversity and predominance of Nemouridae and Baetidae at the reference site and low diversity and predominance of Chironomidae in sites with the highest uranium concentration. Uranium concentrations in producers and consumers increased linearly with uranium concentration in stream water and sediment (p < 0.05). The highest accumulation was found in litter (83.76 ± 5.42 µg g-1) and macrophytes (47.58 ± 6.93 µg g-1) in the most contaminated site. Uranium was highest in scrapers (14.30 ± 0.98 µg g-1), followed by shredders (12.96 ± 0.81 µg g-1) and engulfer predators (7.01 ± 1.3 µg g-1). Uranium in adults of aquatic insects in the riparian zone in all sites ranged from 0.25 to 2.90 µg g-1, whereas in spiders it ranged from 0.96 to 1.73 µg g-1, with no differences between sites (p > 0.05). There was a negative relationship between δ15N and uranium, suggesting there is no biomagnification along food webs. We concluded that uranium is accumulated by producers and consumers but not biomagnified nor dispersed to land with the emergence of aquatic insects.


Assuntos
Invertebrados/metabolismo , Urânio/farmacocinética , Poluentes Químicos da Água/farmacocinética , Animais , Organismos Aquáticos , Bioacumulação , Chironomidae/efeitos dos fármacos , Chironomidae/metabolismo , Monitoramento Ambiental/métodos , Cadeia Alimentar , Água Doce , Insetos/efeitos dos fármacos , Insetos/metabolismo , Invertebrados/efeitos dos fármacos , Mineração , Portugal , Rios , Aranhas/efeitos dos fármacos , Aranhas/metabolismo , Urânio/análise , Poluentes Químicos da Água/análise
20.
Chemosphere ; 242: 124967, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31677506

RESUMO

Mechanistic models based on chemical properties of metals and body size have received substantial attention for their potential application to various metals and to different conditions without required calibration. This advantage has been demonstrated for a number of metals, such as Cd and Ag. However, the capacity of metal-specific chemical properties to explain variations in the accumulation for platinum-group elements (PGEs) has not been investigated yet, although emission of these metals is of increasing concern. Once being released, PGEs exist in the environment in mixtures with other metals. The present study attempted to model the accumulation of Pd and Pt in mixtures with Ag and Cd in the zebra mussel (Dreissena polymorpha) from the aqueous phase; and to investigate the potential application of mechanistic models to Pd and Pt. The present study showed statistically insignificant differences in metal accumulation among size groups in a narrow range of shell length (16-22 mm). Kinetic models could simulate well the accumulation of Cd, Ag, and Pt when metal-specific responses of zebra mussels are taken into consideration. These responses include enhanced immobilisation as a detoxifying mechanism and exchange between soft tissues and shells via the extrapallial fluid. Environmental conditions, e.g. the presence of abiotic ligands such as chloride, might also play an important role in metal accumulation. Significant relationships between the absorption efficiency and the covalent index indicate the potential application of mechanistic models based on this chemical property to Pt.


Assuntos
Dreissena/metabolismo , Modelos Químicos , Poluentes Químicos da Água/farmacocinética , Animais , Bioacumulação , Cádmio/farmacocinética , Cinética , Paládio/farmacocinética , Platina/farmacocinética , Prata/farmacocinética , Poluentes Químicos da Água/análise
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