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1.
Environ Monit Assess ; 193(1): 19, 2021 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-33389183

RESUMEN

The paper focuses on the effect of ponds (geographically isolated wetlands) on water quality within internally drained areas in a river catchment. The important part of the study was the point of formation of a periodic hydrographic network of internally drained areas linked with a main river as well as the identification of the circulation pattern of ions in such a system. The aim of the study was to examine the extent to which ponds pollute the main river upon physical connection with it. Research has shown that ponds participate actively in material circulation-including that of water and biogenic ions. The hydrographic network in Young Glacial areas is subject to very large seasonal changes. In the study area, the total length of the stream network in the dry season equaled 12 km, while in the wet season almost 75 km. At the same time, almost 50% of the internally drained areas in the catchment became connected with the surface runoff network. Such large seasonal changes in the hydrographic network yield large changes in stream water chemistry. In the study area, only 6 ponds were linked to the stream network during the dry season, while in the wet season, this number increased to 125. The parts of catchments featuring the largest changes in the hydrographic network as well as the largest number of ponds temporarily linked with surface runoff networks were characterized by a high content of total nitrogen and phosphorus-up to 244.2 kg N km2 per month and 26.2 kg P km2 per month.


Asunto(s)
Monitoreo del Ambiente , Ríos , Fósforo/análisis , Calidad del Agua , Humedales
2.
Sci Total Environ ; 755(Pt 1): 142931, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33348481

RESUMEN

The ecological efficacy of river restoration projects may change over time, resulting in the loss of their ecological function for targeted species. The goal of this study was to evaluate the rheophilic nursery function of restored floodplain channels over time, by analysing 30 years of monitoring data from 12 restoration projects in the lower river Rhine. We hypothesised that the nursery function would change over time, caused by the combined effects of decreasing flow conditions and succession processes affecting habitat heterogeneity. We found that nursery area suitability for rheophilic fish was almost 4 times higher in two-sided connected channels than in one-sided connected channels, although the response trends of rheophilic fish were similar for both water body types. These response curves showed clear optima with channel age, for rheophilic fish abundance at 13 to 14 years post-restoration, indicating optimal nursery conditions. On the other hand, rheophilic species richness showed a steadily decreasing trend with channel age, suggesting aging channels became less suitable as nursery areas for most rheophilic fish species. The presence of permanent flow was found to be the main driving factor in explaining both rheophilic fish community trends and habitat succession in individual restored channels. We did not observe an effect of habitat heterogeneity on nursery function for rheophilic fish. To create and maintain optimal nursery conditions in restored floodplain channels of strongly anthropogenically influenced rivers such as the river Rhine, we propose a management strategy involving cyclic rejuvenation through human intervention, focusing on restoring permanent flow, with a frequency of on average every 15 years, depending on the rate of aggradation and targeted rheophilic species. We also propose a thorough investigation of the relationship between habitat heterogeneity and nursery success in floodplain channels, as a next step in the identification of suitable nursery areas for rheophilic fishes.


Asunto(s)
Conservación de los Recursos Naturales , Ríos , Adolescente , Animales , Ecosistema , Peces , Humanos , Agua
3.
Sci Total Environ ; 755(Pt 1): 142873, 2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33348482

RESUMEN

Groundwater discharge zones in streams are important habitats for aquatic organisms. The use of discharge zones for thermal refuge and spawning by fish and other biota renders them susceptible to potential focused discharge of groundwater contamination. Currently, there is a paucity of information about discharge zones as a potential exposure pathway of chemicals to stream ecosystems. Using thermal mapping technologies to locate groundwater discharges, shallow groundwater and surface water from three rivers in the Chesapeake Bay Watershed, USA were analyzed for phytoestrogens, pesticides and their degradates, steroid hormones, sterols and bisphenol A. A Bayesian censored regression model was used to compare groundwater and surface water chemical concentrations. The most frequently detected chemicals in both ground and surface water were the phytoestrogens genistein (79%) and formononetin (55%), the herbicides metolachlor (50%) and atrazine (74%), and the sterol cholesterol (88%). There was evidence suggesting groundwater discharge zones could be a unique exposure pathway of chemicals to surface water systems, in our case, metolachlor sulfonic acid (posterior mean concentration = 150 ng/L in groundwater and 4.6 ng/L in surface water). Our study also demonstrated heterogeneity of chemical concentration in groundwater discharge zones within a stream for the phytoestrogen formononetin, the herbicides metolachlor and atrazine, and cholesterol. Results support the hypothesis that discharge zones are an important source of exposure of phytoestrogens and herbicides to aquatic organisms. To manage critical resources within the Chesapeake Bay Watershed, more work is needed to characterize exposure in discharge zones more broadly across time and space.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Animales , Teorema de Bayes , Ecosistema , Monitoreo del Ambiente , Fitoestrógenos , Ríos , Contaminantes Químicos del Agua/análisis
4.
Sci Total Environ ; 756: 143472, 2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33243514

RESUMEN

Two factors complicate the ecological status classification of very large rivers in Europe according to the EU Water Framework Directive: First, current assessment methods do not fully consider the specific ecology of very large rivers (such as lateral connectivity and the role of floodplains for ecological status). Second, most of Europe's very large rivers have been severely altered by human activities such as flood protection, damming and navigation. The aim of our study is to develop an assessment method for very large rivers by identifying suitable biological metrics as the basis for multi-metric bioassessment using benthic invertebrates. Based on the pan-European typology of very large rivers by Borgwardt et al. (2019), we established a river type-specific assessment approach using invertebrate samples from 25 European countries and 94 very large rivers. The frequency and intensity of eight pressures jointly acting on the sampling sites were described, and a selection of suitable invertebrate community metrics were correlated with the pressure intensities to establish pressure-response relationships. The very large river types differ in terms of relevant pressures and pressure combinations, with the invertebrate communities distinctly responding to these pressure patterns. Neozoa dominance correlated strongly with 'navigation', being a major pressure at very large rivers, which entails severe hydro-morphological alterations such as channelization, riparian vegetation alteration and impoundment. Under combined pressures, a critical community turnover became evident in terms of neozoa outnumbering EPT taxa and the ratio of hemilimnic invertebrates decreasing. We propose ten bioassessment metrics, including measures of biological diversity as well as newly generated indicators, for the development of a European type-specific assessment method for very large rivers.


Asunto(s)
Monitoreo del Ambiente , Ríos , Animales , Biodiversidad , Ecosistema , Europa (Continente) , Humanos , Invertebrados
5.
Sci Total Environ ; 756: 144053, 2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33279192

RESUMEN

Sediment trapping within reservoirs is a worldwide phenomenon which impairs the ecological functioning of upstream and downstream ecosystems. It also reduces reservoir water storage volume, which lessens the services dams provide such as hydropower production or flood control and questions their sustainability. Hydraulic flushing is a widely used operation to recover the reservoir volume, but ecological impacts are massive. Recently, environmental awareness led dam operators to modify their management practices: 'Controlled Sediment Flushing Operations' (CSFOs) include environmental objectives in their implementation and are designed to be less harmful for aquatic ecosystems by controlling the flow and Suspended Sediment Concentration (SSC) downstream. However, CSFOs are not yet widespread, their ecological impacts are poorly documented, and comparisons with 'classical' flushing operations are unreported. Here, we analysed impacts on fish of the first CSFO of the Verbois reservoir in 2016, both upstream and downstream of the dam, and compared these with those from the empty flushing of 2012 using the same methodology (Grimardias et al., 2017). Time-series of hydroacoustics surveys enabled us to estimate the fish abundance in the reservoir, while radiotelemetry measured movements and apparent survival below the dam for four representative species. The 2016 CSFO lasted 10 days, and released a mean Suspended Sediment Concentration (SSC) of 3.47 g·L-1 (peak = 11.98 g·L-1). The fish density as assessed by the mean acoustic scattering strength SA in the reservoir did not change significantly pre- and post-CSFO, and SA seasonal estimates of year 2016 did not differ from those of 2015 and 2017. The apparent survival estimated from capture-recapture survey of marked fish (N = 118) decreased significantly during the CSFO for all species and differed across species, while the distances moved downstream increased. By comparison with the 2012 empty flushing, the 2016 CSFO allowed fish to remain in the reservoir, while impacts below the dam were mostly behavioural rather than lethal. Overall, despite significant impacts, the CSFO advantageously replaced 'classical' flushing from an ecological viewpoint. Provided that an acceptable balance between economical, ecological and technical aspects is found, CSFO can be considered for many reservoirs while accounting for their biological and physical site-specificity.


Asunto(s)
Ecosistema , Ríos , Animales , Peces , Inundaciones , Suiza
6.
Chemosphere ; 265: 129096, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33280841

RESUMEN

Arsenic contaminated groundwater is seen as one of the most critical routes of human exposure to geogenic pollutants. Recently around 40 million inhabitants of the world are living in the hazardous zone having groundwater As level >50 µg/L. As problem of groundwater in Bhagirathi-Ganga deltaic plain is well-known for over the last three decades. Hydrogeochemical analytical data related to the As concentration had been analysed to identify the As sources in groundwater of the active floodplains of the Ganga basin in Northern India. The natural background level of As was also estimated using Grubb's test and cumulative probability plots. The natural background level is a crucial parameter for identifying and quantifying groundwater pollution and assessing measures to control pollution. The anthropogenic addition of As in groundwater was separated by the estimated inflection point. The results show that the highest As concentration, which is 8-times more than the permissible limit, is observed at Gyantoli village in Begusarai district in Bihar state. Groundwater is alkaline with a high concentration of HCO3- as compared to other chemical parameters. Further, it indicates the dominance of carbonate weathering and relatively high pH values (range: 8.00-9.00) helps to release As in groundwater. The reducing environment of the aquifer system becomes oxic at the shallow depth due to comparatively shallow groundwater level, and impressive water level fluctuation resulting in vertical mixing of anthropogenic As contaminants.


Asunto(s)
Arsénico , Agua Subterránea , Contaminantes Químicos del Agua , Arsénico/análisis , Monitoreo del Ambiente , Humanos , India , Ríos , Contaminantes Químicos del Agua/análisis
7.
Sci Total Environ ; 756: 144074, 2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33303198

RESUMEN

Recent studies suggest that climate change, with warmer water temperatures and lower and longer low flows, may enhance harmful planktic cyanobacterial growth in lakes and large rivers. Concomitantly, controlling nutrient loadings has proven effective in reducing phytoplankton biomass especially in North America and Western Europe. In addition, the impact of invasive benthic filter-feeder species such as Corbicula on phytoplankton has largely been overlooked in large rivers, leading to even more uncertainty in predicting future trajectories in river water quality. To investigate how nutrient control, climate change and invasion of benthic filter-feeders may affect phytoplankton biomass and composition, we assembled a large database on the entire water course of the River Loire (France) over three decades (1991-2019). We focus on cyanobacteria to provide an in-depth analysis of the 30-year trend and insights on future possible trajectories. Since 1991, total phytoplankton and cyanobacteria biomasses have decreased 10-fold despite warmer water temperature (+0.23 °C·decade-1) and lower summer flow (-0.25 L·s-1·km-2·decade-1). In the long-term, the contribution of planktic cyanobacteria to total biomass was on average 2.8%. The main factors driving total phytoplankton and cyanobacteria biomasses were total phosphorus (4-fold decrease), the abundance of Corbicula clams (from absence before 1998 to 250-1250 individuals·m-2 after 2010), the duration of summer low flows and the intensity of summer heatwaves. The River Loire constitutes an example in Europe of how nutrient control can be an efficient mitigation strategy, counteracting already visible effects of climate change on the thermal regime and flow pattern of the river. This may hold true under future conditions, but further work is needed to account for the climate trajectory, land and water use scenarios, the risk of enhanced benthic biofilm and macrophyte proliferation, together with the spread of invasive filter-feeding bivalves.


Asunto(s)
Bivalvos , Cianobacterias , Aire Acondicionado , Animales , Biomasa , Cambio Climático , Europa (Continente) , Eutrofización , Francia , Humanos , Lagos , América del Norte , Nutrientes , Fósforo/análisis , Fitoplancton , Ríos
8.
Sci Total Environ ; 756: 143697, 2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33307494

RESUMEN

The rupture of Fundão Dam is considered one of the largest environmental disasters in Brazilian history and one of the largest in the world involving tailings dams. The present study analyzed the changes in metal concentrations in the dissolved, suspended particulate matter (SPM) and sediment in the period just after (15 days) and six months after the dam rupture, together with the biological and cytogenotoxic effects, from the collapse site until the Doce River mouth in the Atlantic Ocean. After the dam rupture, the tailings were mainly transported as SPM. After six months, with the deposition, there was a decrease in metal concentrations in dissolved and SPM and increased levels were observed in the sediment. Cr, Ni, Cd and Hg levels in sediment were higher than the threshold effects level (TEL/NOAA), especially six months after the dam rupture. The water induced immediate negative biological effects at different levels of the trophic chain, together with Al, Fe, Mn and Zn accumulation in fish muscle. Both water and sediment also showed cytotoxic, genotoxic and mutagenic effects. These data demonstrate the importance of long-term monitoring with abiotic and biotic parameters to clarify the impacts of mining tailings and can help to direct future monitoring programs.


Asunto(s)
Metales Pesados , Contaminantes Químicos del Agua , Animales , Océano Atlántico , Brasil , Monitoreo del Ambiente , Metales Pesados/análisis , Minería , Propanolaminas , Ríos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
9.
Sci Total Environ ; 756: 143801, 2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33307496

RESUMEN

Soil salinization and nutrient deficiency have emerged as the major factors negatively impacting soil quality and primary productivity in the coastal saline-alkali soil of the Yellow River Delta. Biochar has been proposed as an efficient strategy for promoting plant growth and restoring degraded saline-alkali soil. However, knowledge is inadequate regarding the effects of adding Spartina alterniflora-derived biochar alone or in combination with effective microorganisms (EM) on the growth of Sesbania cannabina and soil quality in saline-alkali soil. To enhance this knowledge, a pot experiment with different EM treatments (without EM addition, EM-; with EM addition, EM+) and a gradient of biochar treatments (0%, B0; 0.5%, B1; 1.5%, B2; and 3%, B3; biochar weight/soil weight) was conducted. Our results showed that biochar addition alone and in combination with EM significantly increased seed germination, plant height, stem diameter, total biomass and plant nutrient uptake of S. cannabina. Biochar addition, EM addition and their interaction significantly decreased soil salt content efficiently and increased soil total carbon (TC), total nitrogen (TN), available phosphorus (AP) and available potassium (AK) but had little effect on soil pH. Biochar addition increased soil organic carbon, soil NH4+ and NO3-, microbial biomass carbon, and soil enzyme activities and these effects increased in strength when biochar and EM were present simultaneously. Of the treatments, the EM + B3 treatment had the largest effects in terms of inhibiting salinization, increasing soil fertility, elevating soil nutrients and enzyme activities, and improving plant growth. Moreover, the application of biochar and EM promoted the growth of S. cannabina by enhancing plant nutrient uptake, improving soil fertility (e.g., TN, AP, AK, NH4+ and NO3-), and elevating soil enzyme activities (urease and alkaline phosphatase activity). Overall, the integrated use of an appropriate biochar rate (3%) and EM for coastal saline-alkali soil could be an effective strategy to ameliorate soil salinity, improve soil quality and promote plant productivity.


Asunto(s)
Sesbania , Suelo , Álcalis , Carbono , Carbón Orgánico , China , Nitrógeno , Ríos
10.
Sci Total Environ ; 756: 144052, 2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33310223

RESUMEN

Dam operations considerably influence water temperature regimes in rivers, which affects fish spawning activities. Previous studies have focused on the effects of critical temperature (CT) alterations during the spawning period, and largely ignored the effects of accumulated temperature (AT) alterations on gonadal development. Successful spawning relies on the simultaneous achievement of the two thermal requirements at appropriate times. River damming may cause a mismatch between the times of achieving CT and AT thresholds, and in turn influence fish reproduction. In the present study, spawning events of Coreius heterodon (C. heterodon) from 2009 to 2015 in the upper reaches of the Yangtze River, which are under the influence of cascade dams, were analysed based on the times of achievement of CT and AT thresholds. The CT and AT thresholds for C. heterodon spawning were 18.4 °C and 1324.9 °C·d, respectively. Under pre-impoundment conditions, the time of achievement of the AT threshold was 23 d on average later than that under post-impoundment conditions; however, the time of achievement of the CT threshold was similar under both conditions. The time of achievement of the AT threshold was 10 d earlier than that of achievement of the CT threshold in post-impoundment conditions. Earlier achievement of AT thresholds was followed by reduced spawning. The alteration of temperature rhythm caused by reservoir operations could be the major factor decreasing spawning abundance after river damming. The results of the present study could facilitate sustainable reservoir operations with regards to water temperature management, and thereby improve the conservation of fish resources.


Asunto(s)
Cyprinidae , Ríos , Animales , Monitoreo del Ambiente , Reproducción , Temperatura
11.
Chemosphere ; 264(Pt 1): 128383, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33017705

RESUMEN

This study aimed to evaluate water quality using limnological parameters in two sub-basins of the Negro and Apa Rivers, along with the composition and structure of the landscape around the locations sampled in the two sub-basins and their possible contribution to the loss of water quality. We also set out to identify the genotoxic effects on the erythrocytes of Prochilodus lineatus and Leporinus friderici. In particular, we quantified total Cr, Ni and Pb in the muscle of these fish species to determine which genotoxic changes are related to the concentration of metals detected in the fish from these two sub-basins of the Paraguay River Basin. The sub-basin of the Apa River presented a greater proportion of surrounding pastureland in relation to the basin of the Negro River. The erythrocytes of P. lineatus showed a significant difference between the sub-basins for nuclear pyknosis, binucleated cells and lobed nuclei (p < 0.05). In L. friderici, vacuolated nuclei, nuclear pyknosis and lobed nuclei alterations also showed a significant difference between the sub-basins (p < 0.05). The genotoxicity index of the Apa River sub-basin presented higher frequencies of nuclear alterations in P. lineatus and L. friderici (p < 0.05), compared to the Negro River sub-basin. The concentration of total Cr, Ni and Pb in the muscles of P. lineatus and L. friderici in the Negro River sub-basin leads to genotoxic damage, mainly from the induction of lobed nuclei. Based on our results, it can be concluded that toxicogenetic effects in native fish species are an important source of environmental diagnosis in the Upper Paraguay River Basin.


Asunto(s)
Peces , Ríos , Contaminantes Químicos del Agua , Animales , Brasil , Monitoreo del Ambiente , Peces/genética , Paraguay , Toxicogenética , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad , Calidad del Agua
12.
Sci Total Environ ; 757: 143722, 2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33221013

RESUMEN

Antidepressants are drugs with a direct action on the brain's biochemistry through their interaction with the neurotransmitters, such as dopamine, norepinephrine, and serotonin. The increasing worldwide contamination from these drugs may be witnessed through their increasing presence in the urban water cycle. Furthermore, their occurrence has been detected in non-urban water, such as rivers and oceans. Some endemic aquatic animals, such as certain fish and mollusks, have bioaccumulated different antidepressant drugs in their tissues. This problem will increase in the years to come because the present COVID-19 pandemic has increased the general worldwide occurrence of depression and anxiety, triggering the consumption of antidepressants and, consequently, their presence in the environment. This work provides information on the occurrence of the most administrated antidepressants in urban waters, wastewater treatment plants, rivers, and oceans. Furthermore, it provides an overview of the analytical approaches currently used to detect each antidepressant presented. Finally, the ecotoxicological effect of antidepressants on several in vivo models are listed. Considering the information provided in this review, there is an urgent need to test the presence of antidepressant members of the MAOI and TCA groups. Furthermore, incorporating new degradation/immobilization technologies in WWTPs will be useful to stop the increasing occurrence of these drugs in the environment.


Asunto(s)
Contaminantes Químicos del Agua , Antidepresivos , Monitoreo del Ambiente , Humanos , Pandemias , Ríos , Aguas Residuales/análisis , Contaminantes Químicos del Agua/análisis
13.
Environ Sci Pollut Res Int ; 28(1): 1254-1266, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33222066

RESUMEN

The EU directive 2013/39/EU has incorporated four biocidal compounds as priority substances: diuron, isoproturon, cybutryne, and terbutryn. The research was undertaken to determine the concentration of biocides in surface waters in three locations in southern Poland: the Wisla River in Kraków, the Wisloka River in Mielec, and the drainage ditch draining water from arable fields located near Mielec. Environmental samples were taken in two series: winter (February) and spring (May and June). The analyses were carried out using gas chromatography with mass spectrometry. The seasonality of biocides in surface waters was observed. In winter samples, the concentrations were below MQL, while in spring, they ranged from a few to several dozen nanograms per liter. The highest concentrations of all analyzed compounds were recorded in water taken from the Wisla River. According to directive 2013/39/EU, the maximum allowable concentration was exceeded only in the case of cybutryne in water from the Wisla, both in May and in June. The assessment of the toxicity with the tested compounds was defined based on the Environmental Risk Assessment method. Low risk was estimated for diuron and isoproturon, while moderate risk for terbutryn and cybutryne.


Asunto(s)
Contaminantes Químicos del Agua , Monitoreo del Ambiente , Cromatografía de Gases y Espectrometría de Masas , Polonia , Medición de Riesgo , Ríos , Agua , Contaminantes Químicos del Agua/análisis
14.
Sci Total Environ ; 757: 143815, 2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33250238

RESUMEN

Spatio-temporal distributions and bioaccumulation characteristics of freshwater cyanobacterial toxins, such as microcystins (MCs) in the Geum River Estuary, South Korea, were investigated during summer. Environmental multimedia samples (water, suspended particulate matter (SPM), and sediments) and tidal flat organisms (polychaetes, decapods, amphipods, and bivalves) were collected from regions inside and outside of the estuary dam for MCs analysis. Phytoplankton communities in the Geum River (freshwater) and estuarine area (brackish water) were also analyzed in order to understand the relationship with MCs concentrations. Seasonal variation in the structure of phytoplankton communities was detected in the Geum River, with a relatively high density of Cyanophyta in summer. MC concentrations were strongly correlated to water temperature, chlorophyll a, and cyanobacterial density. MC-LR was the most abundant MC variants in environmental samples. Dissolved MCs remained for longer periods and were more widely distributed in the coastal environments compared to particulate MCs. The distribution coefficients between water and SPM (Kd-SPM) and between water and sediments (Kd-sediment) of MCs showed that the phase shift of MCs in the environmental samples occurred in the estuary. Kd-SPM declined from the inside to outside regions of the estuary dam, and was mainly attributed to differences in the half-lives of MCs in dissolved (4.7 d for MC-LR) and particulate phases (0.44-0.52 d for MC-LR). Species-specific bioaccumulation of MCs occurred in tidal flat organisms, with relatively high bioaccumulation factors of MCs being detected in polychaetes and decapods compared to amphipods and bivalves. Overall, this study advances our understanding on the distribution, transport, fate, and bioaccumulation of MCs in estuarine and coastal environments.


Asunto(s)
Estuarios , Geum , Animales , Bioacumulación , Clorofila A , Monitoreo del Ambiente , Microcistinas/análisis , Multimedia , República de Corea , Ríos
15.
Sci Total Environ ; 757: 143794, 2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33272603

RESUMEN

Viticulture plays an important role in generating income for small farms globally. Historically, vineyards use large quantities of phytosanitary products, such as Bordeaux mixture [Ca(OH)2 + CuSO4], to control plant diseases. These products result in the accumulation of copper (Cu) in the soil and increases the risk of transfer to water bodies. Thus, it is important to evaluate whether the presence of Cu-bearing particles in water is toxic to aquatic fauna. This study conducted chemical, mineralogical, and particle size evaluations on water samples and sediments collected from a watershed predominantly cultivated with old vineyards. The proportion of Cu-rich nanoparticles (<10 nm) in the sediment was ~27%. We exposed zebrafish to different dilutions of water and sediment samples that collected directly from the study site (downstream river) under laboratory conditions. Then, we evaluated their exploratory behavior and the stress-related endocrine parameter, whole-body cortisol. We also carried out two experiments in which zebrafish were exposed to Cu. First, we determined the median lethal concentration (LC50-96 h) of Cu and then assessed whether Cu exposure results in effects similar to those associated with exposure to the water and sediment samples collected from the study site. The water and sediment samples directly impacted the exploratory behavior of zebrafish, showing clear anxiety-like behavioral phenotype and stress in terms of cortisol increase (during the second rain event). The Cu exposure did not mimic the same behavioral changes triggered by the water and sediment samples, although it had caused similar stress in the fish. Our results highlight that even at low concentrations, the water and sediment samples from vineyard watershed runoff were able to induce behavioral and endocrine changes that may harm the ecological balance of an aquatic environment.


Asunto(s)
Contaminantes Químicos del Agua , Agua , Animales , Granjas , Sedimentos Geológicos , Ríos , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad , Pez Cebra
16.
Sci Total Environ ; 757: 143825, 2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33280872

RESUMEN

Due to the enhancement of human activities on the global scale, the total amount of atmospheric nitrogen (N) deposition and the rate keep increasing, which seriously affect the structure and function of terrestrial ecosystems. In order to study the effects of N deposition on the soil structure and function of coastal saline wetlands, we established a long-term nitrogen deposition simulation platform in 2012 in the Yellow River delta (YRD). Herein, we analyzed the composition and diversity of the soil microbial community under different N deposition treatments (LNN, MNN and HNN, which stand for 50 kg N ha-1 yr-1, 100 kg N ha-1 yr-1, and 200 kg N ha-1 yr-1) and in a water-only control (CK). The results showed that with the increasing level of N deposition, α-diversity (Shannon and Simpson indices) decreased significantly, and the composition of the microbial community changed. At the phylum level, compared with CK, the relative abundance of Chloroflexi increased significantly under the treatment of HNN (P = 0.002), but the relative abundance of Chlorobi (P = 0.013) and Verrucomicrobia (P = 0.035) decreased significantly. At the genus level, compared with CK, the relative abundance of Bacillus (P = 0.01) and Halomonas (P = 0.042) increased significantly with HNN treatment. Bacillus and Nitrococcus showed a significant correlation with soil NH4+-N. The results suggest that the response of microorganisms to N deposition treatments varied by the concentration, and the deposition of a high concentration would increase the nutrients in the soil, but reduce the diversity of soil microorganisms, causing a negative impact on the coastal wetland ecosystem of the YRD.


Asunto(s)
Microbiota , Humedales , China , Humanos , Nitrógeno/análisis , Ríos , Suelo , Microbiología del Suelo
17.
Environ Pollut ; 269: 115740, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33307399

RESUMEN

Solvent use and paint consumption are significant source sectors of volatile organic compounds (VOCs) emissions in China. The occupational painters have high risk of health effect due to exposure to high VOCs concentration. However, the toxic components in coating environment have not been carefully identified, and the health risks of VOCs exposure have not been sufficiently assessed. This study collected air samples from nine workshops of three major coating sectors in the Yangtze River Delta of China, namely cargo container coating, ship equipment coating, and furniture coating, to evaluate the non-cancer and cancer risk of toxic VOCs exposure to occupational painters under a normal working condition. The results show that the container coating had highest cancer risk (2.29 × 10-6-5.53 × 10-6) exceeding the safe limit of 1.0 × 10-6, while non-cancer risk of all workshops was lower than acceptable level of 1. Ethylbenzene and 1,2-dichloropropane should be targeted for priority removal during the container coating process in attempt to reduce adverse health effect on the occupational painters. This study helps better understand the health risk of VOCs exposure in coating workshops in China and provides information for policy-makers to formulate possible control of specific toxic compounds during coating process.


Asunto(s)
Contaminantes Atmosféricos , Compuestos Orgánicos Volátiles , Contaminantes Atmosféricos/análisis , China , Monitoreo del Ambiente , Pintura , Medición de Riesgo , Ríos , Compuestos Orgánicos Volátiles/análisis
18.
Environ Pollut ; 269: 116110, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33310493

RESUMEN

Little is known about the fate of oil spills in rivers. Hyporheic flows of water through river sediments exchange surface and groundwater and create upwelling and downwelling zones that are important for fish spawning and embryo development. Risk assessments of oil spills to rivers do not consider the potential for hyporheic flows to carry oil droplets into sediments and the potential for prolonged exposure of fish to trapped oil. This project assessed whether oil droplets in water flowing through gravel will be trapped and whether hydrocarbons partitioning from trapped oil droplets are bioavailable to fish. Columns packed with gravel were injected with oil-in-water dispersions prepared with light crude, medium crude, diluted bitumens, and heavy fuel oil to generate a series of oil droplet loadings. The concentrations of oil trapped in the gravel increased with oil loading and viscosity. When the columns were perfused with clean water, oil concentrations in column effluents decreased to the detection limit within the first week of water flow, with sporadically higher concentrations associated with oil droplet release. Despite the low concentrations of hydrocarbons measured in column effluent, hydrocarbons were bioavailable to juvenile rainbow trout (Oncorhynchus mykiss) for more than three weeks of water flow, as indicated by strong induction of liver ethoxyresorufin-o-deethylase activity. These findings indicate that ecological risk assessments and spill response should identify and protect areas in rivers sensitive to contaminant trapping.


Asunto(s)
Aceites Combustibles , Agua Subterránea , Contaminantes Químicos del Agua , Animales , Disponibilidad Biológica , Citocromo P-450 CYP1A1/metabolismo , Ríos , Contaminantes Químicos del Agua/análisis
19.
Sci Total Environ ; 757: 143988, 2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33310576

RESUMEN

We describe the multi-decadal delayed effects of flood on macroinvertebrate community structure using 33 years of monitoring data on macroinvertebrates, water quality, and climate, and 51 years of hydrological data, spanning 2300 km of the Murray River, Australia. We used distributed lag nonlinear models in a four-step analytical process, including 1) modelling macroinvertebrate community structure, represented as a set of principle coordinate axes, as a function of a lagged hydrologic index and other environmental variables using distance-based redundancy analysis 2) visualizing the patterns of delayed effects of flows on the PCO axes, 3) modelling the abundances of groups of taxa along individual PCO axes, and 4) combining the two sets of models in a counterfactual analysis to predict the community structure under flood and no-flood scenarios to describe the multi-decadal trajectory of the community following a flood. Our findings show an increase in abundance of most taxa of filtering-gathering collectors, scrapers, and shredders in the long term that implicates an influx of organic matter of all sizes, from particulate organic matter to coarse and large woody debris, that serves directly or indirectly as a food resource and/or habitat. Our approach enabled the isolation of a flood impact from the confounding effects of other flow events and environmental variables, overcoming a substantial challenge in ecohydrological studies.


Asunto(s)
Inundaciones , Ríos , Animales , Australia , Ecosistema , Monitoreo del Ambiente , Invertebrados , Dinámicas no Lineales
20.
Sci Total Environ ; 757: 144188, 2021 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-33316512

RESUMEN

This special issue of STOTEN is dedicated to presenting the results of the WWF-Australia "Rivers to Reef to Turtles" project, which focused on investigating pollutants in the environment, food and bodies of green turtles (Chelonia mydas) on the Great Barrier Reef (GBR). The project brought together organic and inorganic trace chemical analysis, bioanalytical tools and individual health monitoring to investigate potential causes of an unusual mortality event in 2012. Together, the ten studies in this special issue highlight the shortcomings of current chemical monitoring and impact assessment programmes, which are focused on a limited number of prioritised chemicals and fail to account for the incredible diversity of toxicants released by human activities. It is essential that future management efforts consider the impact of these contaminants on the GBR, already under threat from global warming and sediment and nutrient runoff. Understanding the impact that chemical contaminants have on turtles not only informs green turtle conservation but can also, as they are sensitive and long-lived bioindicators of environmental health, guide efforts to protect, conserve and restore marine ecosystems such as the GBR.


Asunto(s)
Tortugas , Contaminantes Químicos del Agua , Animales , Australia , Ecosistema , Monitoreo del Ambiente , Ríos , Contaminantes Químicos del Agua/análisis
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