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1.
Environ Monit Assess ; 192(11): 677, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025276

RESUMO

Local water quality indices (WQIs) are usually developed by modifying internationally recognized indices, which are considered reference index. In previous works on WQIs, the performance of local and reference indices has not been compared with each other. Therefore, the question crosses the mind whether using local or international indicators individually can show all qualitative aspects of a water resource. In this study, it was aimed to make this comparison between NSFWQIm (National Sanitation Foundation Water Quality Index) as the reference index and IRWQIsc (Iranian Water Quality Index for Surface Water Resource-Conventional Parameters) as the local one through a case study (Sefidroud River in northern Iran). Based on the results, the indices' performance in representing the seasonal and spatial fluctuations of the river water quality was almost similar. However, the water quality scores obtained by the two indices were somewhat different. Based on NSFWQIm, the average water quality score of the river was about 49.0, by which the water was categorized in "bad" class, while IRWQIsc represented an average score of 56.1, which corresponds to "fairly good" class. Therefore, NSFWQIm identified the water quality with stricter criteria than IRWQIsc, regarding the public health. On the other hand, according to relative standard deviations (0.17 for NSFWQIm, 0.21 for IRWQIsc) of the obtained water qualities, IRWQIsc better distinguished between high and low water qualities of the river. Accordingly, in order to better interpret the quality conditions of surface water resources in Iran, it is necessary to use both indices since NSFWQIm (reference index) attracts attention to stricter international standards and requirements, while IRWQIsc (local index) causes more focus on seasons or locations with the worst water quality.


Assuntos
Rios , Qualidade da Água , Monitoramento Ambiental , Irã (Geográfico) , Poluição da Água/análise
2.
Sci Total Environ ; 741: 140071, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887015

RESUMO

The application of quantitative polymerase chain reaction (qPCR) based microbial source tracking (MST) marker genes are increasingly being used to identify contaminating sources and inform management decisions. In this study, we assessed interlaboratory agreement on duplicate environmental water samples collected from estuarine and freshwater locations, by comparing results of qPCR based testing for Bacteroides HF183, crAssphage CPQ_056, and pepper mild mottle virus (PMMoV). The overall agreements (co-detection and non-co-detection) between CSIRO Land and Water (CLW) laboratory and Sydney Water (SW) laboratory for the HF183, crAssphage CPQ_056 and PMMoV marker genes for duplicate water samples were 74, 75 and 74%, respectively. Cohene's kappa (k) revealed fair to moderate agreements and acceptable relative percent difference (RPD) values of <15% for duplicate samples. The pooled mean abundances of HF183, CPQ_056, and PMMoV in measurable samples at the CLW laboratory were 5.19 ± 0.93, 5.12 ± 0.82, and 4.42 ± 0.65 log10 copies/L, respectively. However, the pooled mean abundances were significantly lower at the SW laboratory, HF183 (4.58 ± 0.84 log10 copies/L), crAssphage CPQ_056 (4.20 ± 0.63 log10 copies/L), and PMMoV (3.89 ± 0.41 log10 copies/L). At individual sample level, most of the paired samples had <1 log10 difference. Significant positive Spearman rank correlations were obtained between two laboratories for the HF183 (Rs = 0.65; p < 0.05), CPQ_056 (Rs = 0.79; p < 0.05), and PMMoV (Rs = 0.54; p < 0.05) marker genes. Several factors such as standards, qPCR platforms, PCR inhibitors, nucleic acid extraction efficiency and low levels of targets in some samples may have contributed to the observed discrepancies. Results presented in this study highlight the importance of standardized protocol, laboratory equipment (such as digital PCR), sample processing strategies and appropriate quality controls that may need implementation to further improve accuracy and precision of results between laboratories.


Assuntos
Rios , Esgotos , Monitoramento Ambiental , Fezes , Água Doce , Microbiologia da Água , Poluição da Água/análise
3.
Chemosphere ; 258: 127412, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32947661

RESUMO

The objective of this study was development of a simple and reliable microbial toxicity test based on fermentative bacteria to assess heavy metal (Hg2+, Cu2+, Cr6+, Ni2+, As5+, or Pb2+)-contaminated water. The dominant species of test organisms used in this study was a spore-forming fermentative bacterium, Clostridium guangxiense. Toxicity of water was assessed based on inhibition of fermentative gas production of the test organisms, which was analyzed via a syringe method. Overall, the fermentative bacteria-based test kits satisfactorily identified increased toxicity of water as water was contaminated with high amounts of heavy metals; however, levels of inhibition were dissimilar depending on the species of metals. Inhibitory effects of Hg2+, Cu2+, Cr6+, and Ni2+ were considerably greater than those of As5+ and Pb2+. The 24 h half-maximum effective concentrations (EC50) for Hg2+, Cu2+, Cr6+, Ni2+, As5+, and Pb2+ were analyzed to be 0.10, 0.51, 1.09, 3.61, 101.33, and 243.45 mg/L, respectively, confirming that Hg2+, Cu2+, Cr6+, and Ni2+ are more toxic to fermentative gas production than As5+ and Pb2+. The fermentative bacteria-based toxicity test represents an improvement over other existing toxicity tests because of ease of end-point measurement, high reproducibility, and favorable on-site field applicability. These advantages make the fermentative bacteria-based test suitable for simple and reliable toxicity screening for heavy metal-contaminated water.


Assuntos
Monitoramento Ambiental/métodos , Metais Pesados/toxicidade , Poluentes Químicos da Água/toxicidade , Bactérias , Clostridium , Fermentação , Mercúrio/análise , Metais Pesados/análise , Reprodutibilidade dos Testes , Poluentes Químicos da Água/análise , Poluição da Água/análise
4.
Water Res ; 183: 116085, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32750535

RESUMO

Human mitochondrial DNA provides a promising target for fecal source tracking because it is unique and intrinsic to humans. We developed a TaqMan chemistry assay, hCYTB484, targeting the cytochrome b gene of the human mitochondrial genome on a droplet digital PCR (ddPCR) platform and compared the performance of hCYTB484 with the HF183/BacR287 assay, a widely used assay targeting human-associated Bacteroides. For both assays, we defined the analytical limit of detection and analytical lower limit of quantification using frequency of detection and imprecision goals, respectively. We then established these analytical limits using empirical ddPCR data, presenting a novel approach to determining the analytical lower limit of quantification. We evaluated assay sensitivity using individual human feces from US, Bangladesh, and Mozambique and evaluated assay specificity using cow, pig, chicken, and goat samples collected from the US. To compare assay performance across a range of thresholds, we utilized receiver operating characteristic curves. The hCYTB484 marker was detected and quantifiable in 100% of the human feces from the 3 geographical distant regions whereas the HF183/BacR287 marker was detectable and quantifiable in 51% and 31% (respectively) of human feces samples. The hCYTB484 marker also was more specific (97%), having fewer detections in pig, chicken, and goat samples than the HF183/BacR287 marker (80%). The higher performance of the hCYTB484 marker in individual feces from geographically distant regions is desirable in the detection of fecal pollution from sources to which fewer individuals contribute, such as the non-sewered forms of sanitation (e.g. pit latrines and septic tanks) that serve most of Earth's population and carry the highest risk of exposure to fecal-oral pathogens.


Assuntos
Bacteroides/genética , DNA Mitocondrial , Animais , Bangladesh , Bovinos , Monitoramento Ambiental , Fezes , Feminino , Humanos , Reação em Cadeia da Polimerase , Suínos , Microbiologia da Água , Poluição da Água/análise
5.
Sci Total Environ ; 743: 140531, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32758812

RESUMO

The performance of eight microbial source tracking (MST) markers was evaluated in a low-resource, tropical community located in Iquitos, Peru. Fecal samples from humans, dogs, cats, rats, goats, buffalos, guinea-pigs, chickens, ducks, pigeons, and parrots were collected (n = 117). All samples were tested with human (BacHum, HF183-Taqman), dog (BactCan), pig (Pig-2-Bac), and avian (LA35, Av4143, ND5, cytB) markers using quantitative PCR (qPCR). Internal validity metrics were calculated using all animal fecal samples, as well as animal fecal samples contextually relevant for the Peruvian Amazon. Overall, Pig-2-Bac performed best, with 100% sensitivity and 88.5% specificity to detect the correct fecal source. Human-associated markers showed a sensitivity of 80.0% and 76.7%, and specificity of 66.2% and 67.6%. When limiting the analysis to contextually relevant animal fecal samples for the Peruvian Amazon, Av143 surpassed cytB with 95.7% sensitivity and 81.8% specificity. BactCan demonstrated 100% sensitivity and 47.4% specificity. The gene copy number detected by BacHum and HF183-Taqman were positively correlated (Pearson's correlation coefficient: 0.785), as well as avian markers cytB with Av4143 (Pearson's correlation coefficient: 0.508) and nd5 (Pearson's correlation coefficient: 0.949). These findings suggest that markers such as Av4143, Pig2Bac, cytb and BacHum have acceptable performance to be impactful in source attribution studies for zoonotic enteric disease transmission in this and similar low-resource communities.


Assuntos
Galinhas , Monitoramento Ambiental , Animais , Biomarcadores , Gatos , Cães , Fezes , Cobaias , Humanos , Peru , Ratos , Microbiologia da Água , Poluição da Água/análise
6.
Mar Pollut Bull ; 157: 111327, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32658692

RESUMO

Marine litter is a world-wide problem, but the knowledge on this topic in remote areas such as the poles and the deep-sea is still limited. This paper seeks to provide the first accounts of deep-sea litter in the South-Western Caribbean Sea. The survey used 5066 still images from ROV video surveys around four hydrocarbon exploratory drilling zones. Forty-eight deep-sea litter items were found at depths between 427 and 2561 m, and analyzed by three different marine litter classifications. Plastic was the most frequent material (65%) and general litter the main category (69%). Almost half of the deep-sea litter items were found close to marine organism. This baseline is a first step to further research of human impact on the marine bottoms of the Caribbean. The paper highlights the importance of deep-sea litter as a descriptor of marine pollution, and the role of scientific cooperation between off-shore industry and the academy.


Assuntos
Monitoramento Ambiental , Resíduos/análise , Região do Caribe , Mar Mediterrâneo , Plásticos , Poluição da Água/análise
7.
Environ Monit Assess ; 192(8): 495, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32642961

RESUMO

Sustainable reservoir watershed management is crucial to maintain a water supply system. The purpose of this study is to assess the pollution sources of the Bao-Shan Reservoir, which is an off-stream reservoir and is the study reservoir herein. Most water source of the Bao-Shan Reservoir is from the Shang-Ping Watershed. This study applies the EPA's Storm Water Management Model (SWMM) and the Vollenweider model (VM) to analyze the pollution hotspots in the reservoir watershed and the impact of the pollutions on the reservoir water quality. The results indicate that non-point source pollution is the main pollution in the Shang-Ping Watershed. The pollution hotspots are located in the sub-watersheds S1, S3, S4, and S5. These sub-watersheds have higher total phosphorus (TP) loads per unit area. In order to protect the water quality of the Bao-Shan Reservoir, this study suggests that the TP load entering the reservoir needs to be reduced by about 16% to 24%. The control of non-point source pollution needs to be preferentially implemented in the Shang-Ping Watershed. The analysis and discussion in this study are a useful reference for reservoir watershed management.


Assuntos
Monitoramento Ambiental , Qualidade da Água , China , Eutrofização , Nitrogênio/análise , Fósforo/análise , Poluição da Água/análise , Abastecimento de Água
8.
Huan Jing Ke Xue ; 41(2): 702-712, 2020 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608729

RESUMO

The Wenyu River is an important ecological corridor of Beijing. In this study, the spatio-temporal dynamics of water quality and phytoplankton community in the Wenyu River in 2006, 2011, and 2018, as well as their relationship were thoroughly analyzed by historical data analysis and field surveys. Results show that the water quality in the Wenyu River improved significantly from serious pollution owing to pollution containment. The major water pollutant has shifted from ammonia nitrogen (NH4+-N) to total nitrogen (TN). Compared with 2011, the average multiple of NH4+-N and total nitrogen TN exceeding the national standard were reduced by factors of 0.29-0.33 and 2.77-2.39, respectively, in 2018. The average concentration of NH4+-N and TN decreased from 15.52-19.16 mg·L-1 and 20.21-19.58 mg·L-1 in 2011 to 1.93-2.66 mg·L-1 and 5.66-6.79 mg·L-1 in 2018. Moreover, dissolved oxygen (DO) and NH4+-N concentrations in the Wenyu River and its tributaries, the Qinghe River, almost met requirements of their water function zoning target. Corresponding with the water quality improvement, the phytoplankton and community species increased dramatically. Phytoplankton species increased from 6 to 8 phyla, as well as community species. The dominant species changed from Chlorophyta in 2006 to the Cyanophyta in 2011, then to Bacillariophyta in 2018. The Shannon-Wiener diversity index (H') and evenness Pielou index (J) had improved. However, the major dominant species such as Cyclotella and Melosira persisted, and the Wenyu River was still in the eutrophication state in 2018. Statistical analysis results indicated that Cyanophyta, Bacillariophyta, and other algae abundance were significantly correlated with DO, pH, NH4+-N, TN, and TP.


Assuntos
Fitoplâncton/classificação , Rios , Poluição da Água/análise , Qualidade da Água , Pequim , China , Estações do Ano , Análise Espaço-Temporal
9.
Environ Sci Pollut Res Int ; 27(31): 38849-38860, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32632688

RESUMO

Well-defined targets for nitrogen (N) release into the local environment are essential for water management in creeks, but difficulties often arise from working with data that are too sparse to achieve reliable evaluations. Here, a simulation-optimization approach based on the QUAL2K model was developed to put forward strategies for nitrogen pollution control in a creek with sparse data in Shixi Creek, southeast China. The model showed good agreement with field observations from 22 sampling sites sampled over the period from March 2017 to February 2019, with normalized objective function (NOF) less than 0.360. Based on this model, the water pollutant sources in the creek were distinguished and analyzed. Rural sewage discharge in Shixi Creek was the major factor threatening water quality in the stream. Seasonal variations may influence the transformation of riverine N. To make more than 80% of the area in Shixi Creek meet the water quality standard of grade III, an optimized approach is to reduce more than 55% of the N pollution from point source pollution and 10% from nonpoint source pollution. This study proposed an approach that can effectively evaluate strategies for water management in a creek watershed with sparse data.


Assuntos
Monitoramento Ambiental , Nitrogênio/análise , China , Rios , Poluição da Água/análise , Qualidade da Água
10.
Artigo em Inglês | MEDLINE | ID: mdl-32668595

RESUMO

Deteriorating surface water quality has become an important environmental problem in China. In this study, river water quality was monitored in July (wet season) and October (dry season) 2019 at 26 sites, and a water quality index (WQI) and positive matrix factorization (PMF) model were used to assess surface water quality and identify pollution sources in the Beichuan River basin, Qinghai Province, China. The results showed that 53.85% and 76.92% of TN, 11.54% and 34.62% of TP, 65.38% and 76.92% of Fe, and 11.54% and 15.38% of Mn samples in the dry and wet seasons, respectively, exceeded the Chinese Government's Grade III standards for surface water quality. The spatial variation in water quality showed that it gradually deteriorated from upstream to downstream as a result of human activity. The temporal variation showed that water quality was poorer in the wet season than in the dry season because of the rainfall runoff effect. The PMF model outputs showed that the primary sources of pollution in the wet season were mineral weathering and organic pollution sources, domestic and industrial sewage, and agricultural and urban non-point pollution sources. However, in the dry season, the primary sources were mineral weathering and organic pollution sources, industrial sewage, and domestic sewage. Our results suggest that the point pollution sources (domestic and industrial sewage) should be more strictly controlled, as a priority, in order to prevent the continued deterioration in water quality.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Poluição Química da Água/análise , Poluição da Água/estatística & dados numéricos , Qualidade da Água , China , Análise Fatorial , Humanos , Rios/química , Estações do Ano , Análise Espaço-Temporal , Poluição da Água/análise
11.
Sci Total Environ ; 744: 140898, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-32721677

RESUMO

Contamination of surface and groundwater systems with human and animal faecal matter leads to exposure of reliant populations to disease causing micro-organisms. This exposure route remains a major cause of infection and mortality in developing countries, particularly rural regions. To meet the UN's sustainable development goal 6: Ensure availability and sustainable management of water and sanitation for all, we need to identify the key controls on faecal contamination across relevant settings. We conducted a high-resolution spatial study of E. coli concentration in catchment drainage waters over 6 months in a mixed land-use catchment in the extensive karst region extending across impoverished southwest China. Using a mixed effects modelling framework, we tested how land-use, karst hydrology, antecedent meteorological conditions, agricultural cycles, hydrochemistry, and position in the catchment system affected E. coli concentrations. Land-use was the best predictor of faecal contamination levels. Sites in urban areas were chronically highly contaminated, but water draining from agricultural land was also consistently contaminated and there was a catchment wide pulse of higher E. coli concentrations, turbidity, and discharge during paddy field drainage. E. coli concentration increased with increasing antecedent rainfall across all land-use types and compartments of the karst hydrological system (underground and surface waters), but decreased with increasing pH. This is interpreted to be a result of processes affecting pH, such as water residence time, rather than the direct effect of pH on E. coli survival. Improved containment and treatment of human waste in areas of higher population density would likely reduce contamination hotspots, and further research is needed to identify the nature and distribution of sources in agricultural land.


Assuntos
Escherichia coli , Recursos Hídricos , Animais , China , Monitoramento Ambiental , Humanos , Hidrologia , Poluição da Água/análise
12.
J Environ Manage ; 271: 110989, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32579514

RESUMO

As part of a sustainable water resources management, the Lisbon municipality identified groundwater and treated wastewater use increase as two opportunities for better and sustainable water use, with natural safeguard for public health as a priority. In this context, the aim of our research was to assess the suitability of the human-associated marker gene Bacteroides HF183 and the cattle feces-associated CowM2, in routine water quality monitoring as indicators for water use and reuse, providing a tool to more accurately assess public health risks. To this intent, Real-Time quantitative PCR was used for detection of human-associated marker gene Bacteroides HF183 and the bovine-associated CowM2, in a total of 67 samples - groundwater and wastewater at three different treatment stages of a Waste Water Treatment Plant, in Lisbon. HF183 marker gene was detected in treated and untreated wastewater samples, with significant concentration reductions from untreated (6,07 E+07 copies/mL) to secondary treated effluent (1,86 E+05 copies/mL) and a further decrease in tertiary treatment (5,74 E+04 copies/mL). In groundwater samples, this marker was also detected in concentrations ranging from 2,63 E+02 copies/mL to 2,24 E+03 copies/mL. CowM2 marker gene on the other hand was only detected in wastewater samples, with concentrations ranging from 2,47 E+02 copies/mL to 1,17 E+04 copies/mL. Our research indicates that the use of Bacteroides spp. in association with traditional fecal indicator bacteria (FIB) is advantageous for water managing entities in urban settings, such as Lisbon, were drainage system failures may occur. An integrated approach thus provides crucial and more adequate information towards mitigation and correction measures when fecal contamination is detected in environmental waters.


Assuntos
Poluição da Água/análise , Qualidade da Água , Animais , Bactérias , Bacteroides , Bovinos , Monitoramento Ambiental , Fezes , Humanos , Microbiologia da Água
13.
Environ Sci Pollut Res Int ; 27(28): 35303-35318, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32592050

RESUMO

The objective of the present study was to evaluate the water quality data in the Minas Gerais portion of the Doce River basin in order to analyze the current monitoring network by identifying the main variables to be maintained in the network, their possible sources of pollution, and the best sampling frequency. Multivariate statistical techniques (factor analysis/principal components analysis, FA/PCA and cluster analysis, CA) complemented by the analysis of violation of the framing classes were used for this purpose. Water quality variables common to 64 monitoring sites were analyzed for the base period from 2010 to 2017. The water quality variables were analyzed considering the different monitoring campaigns: (a) partial campaigns; (b) total campaigns; and (c) monthly campaigns. It was identified from the FA/PCA results, that, when the partial campaign data were analyzed, the variables selected represent the high susceptibility that the basin presents to erosion and the release of domestic effluents in its water bodies. When the data of total campaigns were evaluated, representative variables of the contamination by heavy metals from industrial and mining activities were included. Therefore, the analysis of violation of the framing classes made possible to identify five critical variables: thermotolerant coliforms, dissolved iron, total phosphorus, and total manganese, which reinforced the results obtained in FA/PCA. Based on the results of the analyses, it was recommended to include variables associated with heavy metal contamination in the partial campaigns, prioritizing the dissolved iron and total manganese, as well as total chloride sampling only for the total campaigns. The evaluated data from the monthly campaigns, the CA showed that although the quarterly monitoring frequency is satisfactory, the monthly monitoring is more appropriate for the monitoring of water quality in the Minas Gerais portion of the Doce River basin.


Assuntos
Poluentes Químicos da Água/análise , Qualidade da Água , Brasil , Monitoramento Ambiental , Rios , Poluição da Água/análise
14.
Environ Sci Pollut Res Int ; 27(28): 35217-35227, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32592055

RESUMO

We analyze the driving mechanism of the River-Director System reform in the article. Using the ordered probit model, the effect of the River-Director System policy was evaluated by observing the monthly water quality data of 170 water areas along the boundary of the Yangtze River system. It determines that the driving force of the local government's basin governance under the river system is mainly the top-down policy directives and that the driving path is effective synergy, rights, and diffusion in the article. We find that the upstream provinces and municipalities that implemented reforms have significantly improved the water quality of the waters in the border basin, compared with the provinces and cities that have not implemented the reform of the river system and the river basins that have implemented policy reforms but are located in the lower reaches of the rivers. At the same time, the city's reforms have significantly improved the quality of the junction basin water body. The implementation of the River-Director System has reduced the occurrences of local pollution emission and improved the water quality of the provincial boundaries through sewage treatment. We further validate the robustness of the basic conclusions by deleting special samples and changing the window type and other robust tests. Finally, through monthly examinations on the implementation of the policy, it finds that the effectiveness of the policy reform became more apparent in the eleventh month.


Assuntos
Rios , Qualidade da Água , China , Cidades , Conservação dos Recursos Naturais , Monitoramento Ambiental , Poluição da Água/análise
15.
Ecotoxicol Environ Saf ; 201: 110782, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32497817

RESUMO

Klebsiella pneumoniae is one of the most important pathogens related to hospital-acquired infections. The incidence of infections by hypervirulent K. pneumoniae (hvKp), especially community-acquired infections, has been increasing in recent decades. The occurrence of multidrug-resistant (MDR) hvKp has been increasingly reported worldwide decreasing the treatment options, which is a concern. Aquatic environments have been considered a reservoir of MDR pathogens, which contribute to the spread of MDR pathogens. Therefore, this study aimed to characterize MDR-hvKp strains obtained from public aquatic environments using whole genome sequencing in Brazil. Resistome analysis showed ARGs to ß-lactams, quinolones, tetracyclines, sulfonamides, and fosfomycin as well as several metal resistance genes. Virulome analysis showed several virulence genes. Besides, genomic islands, CRISPR and prophage-related sequences were also detected. MLST analysis revealed the presence of two novel sequences types (STs) belonging to different clonal complexes (CCs) [ST4415 (CC515) and ST4416 (CC2654)], and one already described [ST661 (CC661)]. The presence of MDR-hvKp lineages in water sources belonging to STs and CCs associated with humans and animals shows the ability of these pathogens to spread to different aquatic environments. This study reports for the first time two novel STs of MDR-hvKp as well as the presence of a rare ST661 closely related to outbreaks in aquatic environments, and contributes to surveillance studies and MDR-hvKp monitoring worldwide.


Assuntos
Farmacorresistência Bacteriana/genética , Metais , Poluição da Água/análise , Animais , Antibacterianos , Brasil , Genes Bacterianos , Genômica , Humanos , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Tipagem de Sequências Multilocus , Virulência/genética , Fatores de Virulência/genética , Sequenciamento Completo do Genoma
16.
Sci Total Environ ; 736: 139573, 2020 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-32474276

RESUMO

Fecal pollution of water bodies poses a serious threat for public health and ecosystems. Microbial source tracking (MST) is used to track the source of this pollution facilitating better management of pollution at the source. In this study we tested 12 MST markers to track human, ruminant, sheep, horse, pig and gull pollution to assess their usefulness as an effective management tool of water quality. First, the potential of the selected markers to track the source was evaluated using fresh fecal samples. Subsequently, we evaluated their performance in a catchment with different impacts, considering land use and environmental conditions. All MST markers showed high sensitivity and specificity, although none achieved 100% for both. Although some of the MST markers were detected in hosts other than the intended ones, their abundance in the target group was always several orders of magnitude higher than in the non-target hosts, demonstrating their suitability to distinguish between sources of pollution. The MST analysis matched the land use in the watershed allowing an accurate assessment of the main sources of pollution, in this case mainly human and ruminant pollution. Correlating environmental parameters including temperature and rainfall with MST markers provided insight into the dynamics of the pollution in the catchment. The levels of the human marker showed a significant negative correlation with rainfall in human polluted areas suggesting a dilution of the pollution, whereas at agricultural areas the ruminant marker increased with rainfall. There were no seasonal differences in the levels of human marker, indicating human pollution as a constant pressure throughout the year, whereas the levels of the ruminant marker was influenced by the seasons, being more abundant in summer and autumn. MST analysis integrated with land use and environmental data can improve the management of fecal polluted areas and set up best practice.


Assuntos
Ecossistema , Rios , Animais , Monitoramento Ambiental , Fezes , Cavalos , Humanos , Ovinos , Suínos , Microbiologia da Água , Poluição da Água/análise , Qualidade da Água
17.
Environ Sci Pollut Res Int ; 27(24): 30034-30049, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32447727

RESUMO

Applying the climatological water balance (WB) concept to describe the relationship between climatic seasonality and surface water quality according to different forms of land use and land cover (LULC) is an important issue, but little explored in the literature. In this paper, we evaluate the influence of WB on surface water quality and its impacts when interacting with LULC. We monitored 11 sampling points during the four seasons of the year, from which we estimate WQI (water quality index) and TSI (trophic state index). We found an effect of the seasonality factor on both WQI values (F(3,30) = 12.472; p < 0.01) and in TSI values (F(3,30) = 6.967; p < 0.01). We noticed that LULC interferes in the way that the water balance influences the WQI and TSI values since in sampling points closest to higher urban density, with little or no riparian protection, the correlation between water balance and water quality was lower. In the stations that had the lowest water surplus and deficit, there was positive linearity between water balance and WQI. However, in the seasons when the surplus and water deficit recorded were extreme, there was no linearity. We conclude that water deficiency impairs the quality of surface water. In the extreme surplus water season, the homogeneity of WQI samples was lower, suggesting a higher interaction between rainwater and LULC. This study contributes to design management strategies of water resources, considering the climatic seasonality for optimization.


Assuntos
Rios , Qualidade da Água , Brasil , Monitoramento Ambiental , Poluição da Água/análise
18.
Chemosphere ; 255: 126933, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32402881

RESUMO

In Bangladesh, groundwater serves as the sole major potable water source. Salinization along with the elevated presence of metals become the major threat for this resource in coastal districts of Bangladesh. Therefore, a multi-hazard approach is planned to appraise the groundwater quality. Probabilistic health risks assessment was employed to quantify risk due to drinking from polluted water in coastal districts. Geostatistical tools, pollution indices, and health risk models were conducted using water quality data from 925 samples (n = 566 in the wet season, and n = 359 in the dry season). Groundwater quality index (GWQI) reveals about 65% of the samples are 'poor to unsuitable' as potable water in the study area. Metals pollution indices are correlated to each other, and demonstrated a diversified outcome. In addition, the multivariate analyses of water quality confirmed the major influencing factors that come from the geogenic processes along with the anthropogenic contribution. Probabilistic health risk assessment results depicted as a medium to high level of non-carcinogenic threats for consumers in the study area. Districts such as Khulna, Satkhira, Bhola, Pirojpur, Bagerhat, Jhalakati, Patuakhali, Barguna, and Lakshmipur possesses a high level of threat due to poor water-quality. Finally, it can be said that the study area is exposed to multi-hazards such as salinization, and elevated metals in groundwater. Substantial human health concerns might arise in the study area due to contaminated water consumption. This study clearly explained the groundwater quality challenges considering the multi-hazard in the coastal districts of Bangladesh, that could be applicable in policy formulation.


Assuntos
Monitoramento Ambiental/métodos , Água Subterrânea/química , Poluentes Químicos da Água/análise , Bangladesh , Ingestão de Líquidos , Água Potável/análise , Água Subterrânea/análise , Humanos , Metais/análise , Medição de Risco , Poluição da Água/análise , Qualidade da Água , Abastecimento de Água
19.
PLoS One ; 15(5): e0232879, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32442172

RESUMO

We explore the possibility of using the varnish (Nutallia obscurata) and Manila (Venerupis philippinarum) clams as biomonitors of microplastics (MPs) pollution. A short review is first provided on the use of bivalves for biomonitoring MPs in aquatic ecosystems. From the conclusions drawn from our review we determine if the sediment dwelling varnish and Manila clam could possibly be good choices for this purpose. We sampled 8 intertidal sites located within two distinct regions of coastal British Columbia, Burrard Inlet (5 sites) and Baynes Sound (3 sites). Each intertidal region had its own particular use; within Burrard Inlet, BMP a heavily used marine park, CP, EB, J, and AP, popular local beaches, and within Baynes Sound, Met and NHB, two intertidal regions heavily exploited by the shellfish industry and RU an intertidal region with limited aquaculture activity. Microfragments were recovered from bivalves collected from all intertidal regions except for AP. Microspheres were recovered primarily from bivalves sampled from Baynes Sound at NHB where high numbers of spheres within sediments had previously been reported. BMP and Met had the highest number of particles present within individual clams which were predominantly high density polyethylene (HDPE) and a polypropylene composite (PPC). Both polymers are extensively used by the shellfish industry in all gear types, as well as in industrial and recreational marine activities. The spatial distribution of recovered MPs was indicative of the anthropogenic use of the intertidal region suggesting these bivalves, for microfragments and microspheres, may be suitable as biomonitors and could prove to be useful tools for determining whether reduction policies for plastics use are having a positive effect on their release into marine environments.


Assuntos
Bivalves , Monitoramento Ambiental/métodos , Microplásticos , Poluição da Água , Animais , Aquicultura/instrumentação , Bivalves/química , Bivalves/crescimento & desenvolvimento , Sedimentos Geológicos , Espectrometria de Massas , Microplásticos/análise , Oceanos e Mares , Análise Espacial , Poluição da Água/análise
20.
Environ Sci Pollut Res Int ; 27(22): 28449-28462, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32418087

RESUMO

Rapid population growth and urbanization has put a lot of stress on existing water bodies in most developing countries such as the Marriott Lake of Egypt. Three constructed wetland configurations including Typha angustifolia planted with enhanced atmospheric aeration by using perforated pipes networks (CWA), planted without perforated pipe network (CWR), and a control non-planted and without perforated pipes wetland (Control) were used in the study. Changes in physicochemical properties and microbial community over four seasons and hydraulic loading rate (HLR) (50, 100, 200, 300, and 400 L day-1 m-1) were monitored using influent from Marriott Lake in Egypt. Overall, the removal performance followed the sequence CWA>CWR>control. Turbidity removal of 98.4%; biochemical oxygen demand (BOD5) removal of 83.3%; chemical oxygen demand (COD) removal of 95.8%; NH3-N removal of 99.9%; total nitrogen (TN) removal of 94.7%; NO3--N and NO2--N increased; total P (TP) removal of 99.7%, Vibrio sp. of 100%, Escherichia coli 100%; total bacterial count of 92.3%; and anaerobic bacteria reduction of 97.5% were achieved by using CWA. Seasonal variation and variation in HLRs had significant effect on performance. The modified planted CWA system enhances the removal of pollutants and could present a novel route for reducing the cost associated with integrating artificial aeration into wetlands.


Assuntos
Typhaceae , Purificação da Água , Análise da Demanda Biológica de Oxigênio , Egito , Nitrogênio , Eliminação de Resíduos Líquidos , Poluição da Água/análise , Áreas Alagadas
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