Water Sites Research Articles

Fate of microplastics in the drinking water production

Microplastics are ubiquitous and consequently enter drinking water treatment plants. Knowledge of the microplastic fate in drinking water production is still very limited, although explorative studies have shown tap water contains low contents of microplastics. In this study, we measure microplastic concentrations in drinking water sources and assess the effectiveness of various drinking water treatment facilities to reduce the microplastic concentrations in water to gain insight into the fate of microplastics. Two analytical techniques, laser direct infrared spectroscopy (LDIR) and optical microscopy, have been applied to cover the particle size range from 20 µm to 5 mm. In total five different drinking water sites were investigated using four different types of raw water (groundwater, surface water, dune filtrate and riverbank filtrate) for drinking water production.This research shows that drinking water treatment removes the majority of microplastics and that concentration of microplastics larger than 20 µm in tap water is less than 2 microplastics particles per litre. Between the different raw water sources it is found that groundwater had by far the lowest microplastics concentrations (< 1.000 microplastics per m3) and the highest concentration was found in riverine water, up to 460.000 particles per m3, specifically in the Lek Canal () (a canal connected to the river Rhine). On average the most abundant plastics found are polyamide (PA, 33%), polyethylene terephthalate (PET, 15%), rubbers (10%), polyethylene (PE, 10%) and chlorinated polyethylene (CPE, 7%). This study also showed that natural treatment steps, such as dune infiltration and sedimentation, remove microplastics effectively. However, this may introduce an adverse effect where microplastics potentially accumulate in the sediment and environment.

Exploitation potential of tidal current energy in Southern China seas

In this study, a numerical investigation of potential sites for tidal current energy extraction is performed in Southern China seas by using the 3D hydrodynamic model FVCOM. The accuracy of the numerical model is validated by using 15-day data from 95 tide stations and 12 current stations. This study identifies 13 potential sites from 6 regions of interest where strong currents and appropriate water depths are suitable for tidal energy development. The modeling results show that the Dongchong Channel of Sansha Bay contains the highest depth-averaged tidal power density, reaching nearly 5000 W/m2. Moreover, the quantitative analysis is performed for different Tidal Current Turbines (TCTs) at the potential sites, considering not only energy yield but also stability of power output. The results indicate that the NNU-300 kW turbine with a rated power of 300 kW and a rotor diameter of 17 m performs the best in most locations in relatively deep water, while the Nova’s M100-D turbine with a rated power of 100 kW and a rotor diameter of 8.5 m is the most appropriate device in relatively shallow water sites. In addition, for most selected types of TCTs, the site H11 near the Fujian coast is the most promising location for future tidal farm development.

Influence of water conditions on peat brGDGTs: A modern investigation and its paleoclimatic implications

Peat brGDGTs (branched glycerol dialkyl glycerol tetraether lipids) have been proposed as an indicator of past temperature changes. However, recent Chinese peat brGDGTs-based Holocene temperature ranges, of >10 °C, are implausible as they are greater than the corresponding ranges obtained using other proxies. This indicates the possible role of additional factor(s) affecting peat brGDGTs, other than temperature. Here, we report the results of a comparative study of surface peat samples, from dry sites (without water cover when sampling) and water sites (with water cover when sampling), from three peatlands with contrasting environmental backgrounds in China. The results clearly demonstrate the influence of water conditions on the molecular distribution of peat brGDGTs. Specifically, the relevant methylation index (MBT′/MBT′5ME, which is proposed as a temperature indicator) of brGDGTs from the water sites is generally lower than that from the dry sites, which may be caused by the decoupling of water/air temperatures and/or different brGDGTs-producing bacterial communities controlled by the water conditions. Considering the long-term process of hydroseral succession from a water body (an analogue of a water site) to a peat bog (an analogue of a dry site), we estimate that around half of the range of the peat brGDGTs-based Holocene temperature record could result from long-term changes in hydrological conditions. If this effect is removed from the peat core MBT′5ME record, the residual range of the peat brGDGTs-based Holocene temperature record from the Narenxia peatland in the Altai Mountains, in arid inland China, is consistent with that of the quantitative pollen-based Holocene temperature record from the same peatland, highlighting the paleoclimatic significance of our findings.

The Concept of Absorbent Environmental Damage in the Context of Civil Responsibility: A Practical Legal Study in the Wetlands of Iraq's Three Major Marshes

The research revolves around the idea of assimilation in the sense of assimilating and integrating contractual responsibility within the scope of tort responsibility that causes damage, which is called the first responsibility. The second responsibility is that which is arranged by the existing or competent government or that is entrusted by virtue of legal care, management, and preservation of the environmental site. The study evaluated four locations inside Iraq's southern marshes: the Hammar marsh, which has two sides, western and eastern, resulting in two sites (A and B); the third location, the so-called central marshes, which is group (C); and the fourth location, Al-Hawizeh Marsh, which is group (D). The theorical, scientific analysis is carried out within the scope of the types of assimilation between the components of the environmental site of water, air, and soil in all layers that include concentrations of heavy elements in a manner that changes the acceptable natural amount, such as soil elements, as well as pollutes the water by poisoning or harms the compositional balance of the air. These components (water, soil, and air) are tacked and determined in light of their connection to each other in the environmental site. The damage assimilation is personified by taking samples that determine the forms of pollution. The damage was shown with examples of damage in the first dimension, and the pattern of absorption in the second dimension was used to infer guilt in the second dimension.

Psychometric properties of screening questionnaires to detect depression in primary healthcare setting in rural Ethiopia

BackgroundMuch of the research about the validity of depression screening questionnaires is on criterion validity. Evidence is scarce on the concurrent, convergent and construct validity of these measures, particularly from low-income countries. This study aimed to evaluate the psychometric properties of depression screening questionnaires in primary healthcare (PHC) in rural Ethiopia.MethodsA facility-based cross-sectional study was conducted with 587 participants recruited from patients attending three PHC facilities and two ‘Holy water sites’ (places where religious treatment is being provided). The psychometric properties of five mental health screening questionnaires were evaluated: the nine item Patient Health Questionnaire (PHQ-9), the two item version of PHQ-9 (PHQ-2), a version of PHQ-9 with two added items of irritability and noise intolerance (PHQ-11), the Patient Health Questionnaire-15 (PHQ-15), and the World Health Organization-Five Well-being Index (WHO-5). Clinical diagnosis of depression was ascertained by psychiatrists. We analyzed data using exploratory factor analysis, Spearman’s rank order correlation coefficient (Rho), the Mann Whitney test of the equality of medians, univariate logistic regression and Cronbach’s alpha.ResultsPHQ-9, PHQ-11 and WHO-5 were found to be unidimensional, with items in each scale highly loading onto one factor (factor loadings ranging from 0.64 to 0.87). The items of each instrument were internally consistent, with Cronbach’s alpha ranging from 0.72 (PHQ-2) to 0.89 (PHQ-11). Scores for all screening scales were moderately or highly correlated with each other (Rho = 0.58 to 0.98) and moderately correlated with anxiety and disability scores. Median scores of all screening scales were significantly higher in those diagnosed with depression. The association of items measuring emotional and cognitive symptoms with the diagnosis of depression was stronger than the association with items measuring somatic symptoms. Irritability and noise intolerance had higher association with depression diagnosis than PHQ-9 items.ConclusionEmotional and cognitive symptoms are more useful than somatic symptoms to predict the diagnosis of depression in the PHC context in Ethiopia. Future research should focus on testing the unidimensionality of PHQ-9, PHQ-11 and WHO-5 using confirmatory factor analysis; establishing the criterion validity of PHQ-11 and WHO-5; and on assessing test-retest reliability of all the measures.

Estimated Erosion from Clearcut Timber Harvests in the Southeastern United States

Abstract Timber harvests with inadequate forestry best management practices (BMPs) can accelerate soil erosion, which has been associated with reductions in water quality and site productivity. Previous studies affirm positive water quality effects accrued by harvesting with BMPs. However, few studies document erosion rates and masses associated with harvest and access network features (e.g., decks, roads, skid trails, stream crossings) across different southeastern regions. This research evaluated 109 recent harvests across eleven southeastern states and three topographically different regions (Coastal Plain, Piedmont, and Mountains). Descriptive statistics of erosion for harvests and access features were developed from USLE-Forest model estimates. Harvests and access network areas were used in conjunction with erosion averages to calculate total erosion masses. Across the southeast, combined network features averaged nearly 12% of total harvest area yet produced approximately 48% of total site erosion due to disproportionately higher erosion rates. Regional differences indicated that the Mountain region had an average overall erosion rate of 6.8 t/ac/yr, whereas the Piedmont and Coastal Plain sites had lower average erosion rates of 2.7 and 2.2 t/ac/yr, respectively. Results suggest that additional BMP implementation strategies may be beneficial for erosion control from roads, skid trails, and stream crossings, particularly in erosive landscapes.

Relational or abyssal?

In the context of ecological emergency and crisis of representation of the capitalist democracy, the battles over water management have become ever more politicised: who is to administer water resources, how, and with what legitimacy? This article examines a disregarded dimension of the recent water conflict in Barcelona by looking into the politics of memory as part of a struggle for legitimacy between the private water company Agbar, and Barcelona en Comú (BeC), the political platform governing the city since 2015, and defending the ‘remunicipalisation’ of water. By combining memory studies and critical discourse analysis we pay attention to the dynamic resignification of the hydraulic infrastructure as spaces or “sites of memory” (lieux de mémoire; Nora, 1998). Barcelona en Comú narrative retrieves a forgotten past of local sites and experiences in public management of water. In contrast, Agbar defends its legitimacy by advancing a narrative of linear progress and social inclusion that re-signifies its 150-year long history and co-opts key “empty signifiers” (Laclau, 2005) from the discourse of the Indignados and BeC. Theoretically, we advance that a temporal turn in political ecology and geography, complementing the concern with spatiality, could usefully draw on memory studies to analyse the growing memorialization of water discourses and sites, as well as their political significance. The article thus investigates a question that has not been systematically explored by political ecologists: how the entanglement of space and historical memory is mobilized in the conflict over the use and management of the environment.

Balancing ecosystem integrity and cultural values at sacred Lake Hora, Ethiopia: The need for conservation of wetland vegetation

AbstractAlthough macrophytes represent important habitats for the plankton communities of shallow lakes and ponds, the role of littoral macrophyte patches in deep crater lakes is not well described. The objective of the present study was to investigate the role of littoral macrophyte vegetation in structuring phytoplankton and zooplankton communities and, therefore, sustaining ecological integrity in a deep tropical crater lake (Hora Lake, Ethiopia). The lake has a surface area of 1.03 km2 and a mean depth of 16.5 m. The area surrounding the lake is a prime location for the celebration of the Oromo thanksgiving festival (Irreecha), which is inscribed by the United Nations Educational, Scientific and Cultural Organization (UNESCO) as an intangible cultural heritage, and also considered sacred by the Oromo people. Measurements of physical, chemical and biological parameters were conducted at fifteen sampling sites in both the littoral and central parts of the lake during the dry and wet seasons in 2017. A total of 28 phytoplankton and 19 zooplankton genera were identified. The phytoplankton and zooplankton communities were dominated by cyanobacteria and rotifers, respectively, at the open water sites. The wetland vegetation was found to be important in reducing potentially toxic and unsightly cyanobacteria. The submerged and emergent vegetation also served as refugia for zooplankton during the wet and dry seasons, respectively. Crustaceans accounted for about 30–45% of the total zooplankton abundance within the vegetation fringes. Their abundance decreased to 5% in the non‐vegetated areas, wherein the community was dominated by rotifers. As the population around the lake, particularly during the festival, may damage the aquatic vegetation, their access to the shoreline should be regulated for conservation and sanitary reasons (e.g. to reduce cyanobacteria growths).

Occurrence, distribution and risk assessment of organophosphate esters (OPEs) in water sources from Northeast to Southeast China

With the wide utilization of organophosphate esters (OPEs) in recent years, OPEs have been detected more frequently in the aquatic environment. However, the distribution of OPEs in drinking source water has rarely been investigated across a large region. In this study, the occurrence and distribution of 13 OPEs were investigated in 23 source water sites from Northeast to Southeast (spacing greater than 3320 km) with a direct injection ultra-performance liquid chromatography-tandem mass spectrometry (UPLC–MS/MS) method. Total OPEs ranged from 218.8 to 636.6 ng/L, with a mean of 380.8 ng/L. The average detected concentration of OPEs in southern cities was higher than that in northern cities. Chlorinated OPEs accounted for 64.74% of the total concentration. Triethyl phosphate (TEP), tri (2-chloroethyl) phosphate (TCEP), and tri (chloropropyl) phosphate (TCPP) were detected in all water samples. Rainfall is a significant factor that affects the OPE concentration (less rainfall, higher concentration). China's OPE concentrations have rapidly reached a median level when compared to those of other countries. Ecological risk assessment showed that most OPEs have no or low risk to organisms (fish, crustacea, algae), except tricresyl phosphate (TCP), which is medium risk. The risk of OPEs in less-rain regions needs to be of greater concern, especially TCP.

A tri-layer floating photocatalyst/adsorbent for the removal of organic compounds from wastewater: Layer-by-layer deposition of silicalite-1 and titania on hollow glass microspheres

Removal of organic compounds from wastewater is necessary to ensure that aquatic organisms are not adversely affected. In the past, it had been shown that zeolite-based systems provide good opportunities for wastewater treatment; however, most of the zeolite systems reported thus far face the disadvantages of sinking in water and saturated adsorption site. Therefore, in the current study, we attempted to develop zeolite-based composite systems with good floatability, adsorption capacity, and photocatalytic activity. In addition, our aim was to ensure that these composites could be easily separated from the treated water. Thus, a tri-layer floating photocatalyst/adsorbent was prepared via the layer-by-layer deposition of silicalite-1, a pure silica MFI-type zeolite (PSZ), and TiO 2 on hollow glass microspheres (HGMs). A thin layer of silicalite-1 was crystallized on the dense walls of HGMs to fabricate floating adsorbents (PSZ-HGMs). Subsequently, a layer of TiO 2 was deposited on PSZ-HGM surfaces using the sol–gel method to develop photocatalytic composites (TiO 2 /PSZ-HGMs). A good PSZ coverage and attachment were achieved on HGM surfaces by adding HGMs to an alkali solution containing tetrapropylammonium hydroxide and tetraethyl orthosilicate, followed by hydrothermal synthesis at 180 °C for 40 h. Subsequent deposition of TiO 2 was effective in homogeneously covering the PSZ surface without clogging the zeolite pores. The wastewater treatment capacity of the synthesized materials was verified using methylene blue (MB). It was found that TiO 2 /PSZ-HGMs, which exhibited both photocatalytic and adsorption activities, acted synergistically with UV-C irradiation to drastically degrade MB concentration by ∼ 98% within 2 h. Therefore, these materials may be considered to have high potential in wastewater-treatment processes. • Newly designed tri-layer floating TiO 2 /pure silica MFI-type zeolite/hollow glass microsphere (TiO 2 /PSZ/HGMs) was developed. • The effects of HGM size distribution, precursor composition, and synthesis time on PSZ layer formation on HGM were examined. • Anatase/rutile-TiO 2 were homogeneously embedded onto PSZ/HGMs without clogging the zeolite pores by using the sol–gel method. • Optimized TiO 2 /PSZ/HGMs could remove 98% of methylene blue under UV-C irradiation for 2 h.

Dynamics of two floating wind turbines with shared anchor and mooring lines

Floating wind farms present the opportunity to harvest wind resources located in deep water sites. Shared mooring designs can contribute in making floating wind energy more cost-competitive, and it is important to understand the new system dynamics that arise. We are presenting here HAWC2Farm, an extension of HAWC2 that can model multiple wind turbines with shared mooring lines. We apply the new modeling capabilities to simulate two 15 MW floating wind turbines on spar floaters with shared mooring lines. We consider two different sites and we identify and compare the natural frequencies and mode shapes of the shared mooring designs with those of an individual moored turbine. Furthermore, we investigate the influence of design parameters on the systems’ natural frequencies and we show that it is possible for a shared mooring design to achieve similar characteristics as a single turbine design. Finally, we test the response of the shared mooring design in steady wind and regular waves and find that the surge displacement of the upstream turbine and its mooring line loads are considerably larger compared to the single turbine case.

Notes on Menisciopsis wailele (Thelypteridaceae), a Critically Endangered Rheophytic Fern Species from Kaua‘i, Hawaiian Islands

Menisciopsis wailele (Thelypteridaceae) is a single-island endemic fern species restricted to the Hawaiian island of Kaua‘i. All observations indicate it is an obligate rheophyte, preferring sites of fast-moving water along concave walls of remote streams and waterfall edges. This paper presents data on its morphology, evolution, taxonomy, distribution, abundance, and ecological characteristics. Based on phylogenetic and geographic evidence, the ancestor of the Hawaiian species of Menisciopsis may have dispersed from the mountains of continental East Asia. A formal IUCN assessment of the species has been completed and is reported here as Critically Endangered (CR B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)).

Interpreting Proteobacteria diversity through 16S rRNA analysis in Manasbal Lake, Kashmir

Bacterial community composition in aquatic ecosystems is of renewed interest for its health as well as the people living in the adjoining areas, and the current work on a freshwater ecosystem in Kashmir Himalayas–the Manasbal Lake was carried out in this backdrop. Water samples were collected from various sampling stations, selected as the zones of special ecological interest and according to the degree of difference in the anthropogenic intrusions in the lake. For identification, the isolated bacterial colonies were subjected to morphological and biochemical characterization, which were further confirmed by targeting their 16S rRNA gene, using 27F and 1492R as the universal bacterial primers. Major bacterial phylum, thus isolated, was proteobacteria with 15 different bacterial species belonging to class alpha-proteobacteria, beta-proteobacteria, and gammaproteobacteria. However, the most diverse class isolated was Alphaproteobacteria comprising seven species followed by Betaproteobacteria comprising six species and Gamma-proteobacteria comprising only two species. The distribution of the bacterial group was seen influenced on a Spatio-temporal scale with the maximum density observed during summer and minimum during winter, further the load was highest for littoral sampling stations in comparison to the open water sites. Proteobacteria are important since they perform basic functions in global transformations of elements. But at the same time, they show close interaction with eukaryotes, both as pathogens and as symbionts.&#x0D; &#x0D;

Amine-incorporated adsorbents with reversible sites and high amine efficiency for CO2 capture in wet environment

CO2 adsorption in wet environments is attractive but difficult in terms of the unsatisfied adsorption capacity and low efficiency of active sites. Herein, we report the fabrication of a thermal-responsive adsorbent with reversible amine sites by copolymerizing N-acryloyl glycinamide (NAGA), N-[3-(dimethylamino)propyl]methacrylamide (DMAPM), and styrene (ST). During adsorption at 20 °C, the tertiary amines of the DMAPM units stretch out and act as the strong sites in water. The adsorption capacity can reach 98 mL g−1, corresponding to the highest amine efficiency (0.99 mol CO2 per mol amine), which is superior to most reported adsorbents. When elevating temperature for desorption, these active sites are shielded in the adsorbent particles because of the formation of intramolecular hydrogen bonds between the NAGA and DMAPM units. The exquisite utilization of thermal responsiveness endows the adsorbents with reversible amine sites and high amine efficiency, making them promising in practical CO2 capture.

Development and evaluation of a water quality index for groundwater quality assessment in parts of Jabalpur District, Madhya Pradesh, India

Abstract Groundwater is an important source for drinking water supply in Jabalpur District, Madhya Pradesh, India. An attempt has been made in this work to understand the suitability of groundwater for human consumption. The parameters of pH, Electrical Conductivity (EC), Copper (Cu), Chromium (Cr), Sulphate (SO4), Iron (Fe), Nitrate (NO3), Chloride (Cl), Total Hardness (TH), Total Alkalinity (TA), and Sodium (Na) were analyzed to estimate the groundwater quality. The water quality index (WQI) has been applied to categorize the water quality, which is quite useful to infer the quality of water for the people and policy makers in the concerned area. The WQI in the study area ranges from 17.90 to 176.88. According to the WQI rating, sites 1, 3, and 4 are not appropriate for drinking water or have low water quality and site 2 has moderate drinking condition, whereas site 5 has excellent drinking condition. The current study suggests that the groundwater of the area with deteriorated water quality needs treatment before consumption. HIGHLIGHTS WQI values in sites 1, 3 and 4 are 106.99, 176.88, 161.25, showing that the groundwater is not suitable for drinking purposes. WQI value in site 5 is 17.90, showing that water is fit for drinking purposes. Principal component analysis reveals that four parameters are responsible for the high values of WQI. The outcome of the study will be helpful in formulating effective drinking water management measures for residents in the Jabalpur region, India.

Metagenomics Insights Into the Microbial Diversity and Microbiome Network Analysis on the Heterogeneity of Influent to Effluent Water.

Sanitizing the water sources of local communities is important to control the spread of microbial resistance genes, especially those for water-borne illnesses. The activities of antibiotic resistance gene (ARG)-host pathogens pose a threat to public health, and it has been estimated that the infection will lead up to 10 million deaths globally by the year 2050. Hence, in this study, we aim to analyze the efficiency of our municipal wastewater treatment plant (WWTP) process in producing pathogen-free water by investigating the microbial composition between influent and effluent water sites. Shotgun metagenomics sequencing using the Illumina platform was performed on the influent and effluent samples of six different WWTP sites located in Johore, Malaysia. After raw data pre-processing, the non-redundant contigs library was then aligned against BLASTP for taxonomy profiling and the Comprehensive Antibiotic Resistance Database for ARG annotation. Interestingly, the alpha-diversity result reported that effluent site samples showed higher abundance and diverse heterogeneity compared to the influent site. The principal component analysis (PCA) and non-metric multidimensional scaling (NMDS) plots also suggested that effluent sites showed high variation in the genetic material due to loosely clustered sample plots, as compared to the tightly clustered influent samples. This study has successfully identified the top three abundant phyla in influent—Proteobacteria, Firmicutes, and Bacteroidetes—and effluent—Proteobacteria, Actinobacteria, and Bacteroidetes—water. Despite the overlap within the top three abundant phyla in influent and effluent sites (Proteobacteria and Bacteroidetes), the ARG composition heat map and drug class phenotype plot bar exhibits a general trend of a downward shift, showing the efficiency of WWTP in reducing opportunistic pathogens. Overall, it was demonstrated that our municipal WWTP efficiently eliminated pathogenic microbes from the influent water before its total discharge to the environment, though not with the total elimination of microorganisms. This metagenomics study allowed for an examination of our water source and showed the potential interaction of species and ARGs residing in the influent and effluent environment. Both microbial profile structure and co-occurrence network analysis provide integrated understanding regarding the diversity of microorganisms and interactions for future advanced water sanitation treatments.

Aquatain\xae causes anti-oviposition, egg retention and oocyte melanization and triggers female death in Aedes aegypti

BackgroundIn arboviral disease systems where the virus can be transmitted from male to female vectors and from one generation to the next, targeting the female (especially when she is gravid) can help alter the persistence of the virus in nature and its transmission. A typical example is Aedes aegypti, which has become unmanageable due to the development of insecticide resistance. Despite evidence that monomolecular surface films prevent the selection of genetic resistance, their potential in Aedes vector control remains largely unexplored.MethodsWe examined the oviposition, egg retention, oocyte melanization, and female mortality of the Cayman Islands strain of Ae. aegypti, using choice (balanced and unbalanced) and no-choice bioassays involving Aquatain® Mosquito Formulation (AMF; Aquatain Products Pty Ltd.), a polydimethylsiloxane–based liquid used for mosquito control.ResultsWhen presented with similar opportunities to oviposit in two sites treated with AMF and two other sites with untreated water (control), egg deposition rates were significantly higher in the untreated water sites than in the AMF-treated sites (P < 0.05). We also observed a matching pattern of egg deposition preference in environments with more options in terms of AMF-treated sites. Females laid significantly more eggs when water was the only available medium than when all sites were treated with AMF (P < 0.05). Also, significantly more mature eggs were withheld in the AMF no-choice environment than in the no-choice test involving only water (P < 0.05). Internal oocyte melanization was not observed in females from the oviposition arenas with the lowest AMF presence (equal-choice and water-based no-choice); in contrast, this physiological response intensified as the number of AMF-treated sites increased. Female death occurred at high rates in AMF-treated environments, and this response increased with the increasing presence of such egg deposition sites.ConclusionsThis study demonstrated that AMF acted as a deterrent signal to ovipositing Ae. aegypti and as an indirect adulticide. These results suggest that AMF may be a promising control tool against the dengue vector, and this warrants further evaluation under field settings.Graphical

The Negative Bidirectional Interaction Between Climate Change and the Prevalence and Care of Liver Disease: A Joint BSG, BASL, EASL, and AASLD Commentary

The Negative Bidirectional Interaction Between Climate Change and the Prevalence and Care of Liver Disease: A Joint BSG, BASL, EASL, and AASLD Commentary

Shared water facilities and risk of COVID-19 in resource-poor settings: A transmission modelling study

Shared water facilities are widespread in resource-poor settings within low- and middle-income countries. Since gathering water is essential, shared water sites may act as an important COVID-19 transmission pathway, despite stay-at-home recommendations. This analysis explores conditions under which shared water facility utilization may influence COVID-19 transmission. We developed two SEIR transmission models to explore COVID-19 dynamics. The first describes an urban setting, where multiple water sites are shared within a community, and the second describes a rural setting, where a single water site is shared among communities. We explored COVID-19 mitigation strategies including social distancing and adding additional water sites. Increased water site availability and social distancing independently attenuate attack rate and peak outbreak size through density reduction. In combination, these conditions result in interactive risk reductions. When water sharing intensity is high, risks are high regardless of the degree of social distancing. Even moderate reductions in water sharing can enhance the effectiveness of social distancing. In rural contexts, we observe similar but weaker effects. Enforced social distancing and density reduction at shared water sites can be an effective and relatively inexpensive mitigation effort to reduce the risk of COVID-19 transmission. Building additional water sites is more expensive but can increase the effectiveness of social distancing efforts at the water sites. As respiratory pathogen outbreaks—and potentially novel pandemics—will continue, infrastructure planning should consider the health benefits associated with respiratory transmission reduction when prioritizing investments.

Water quality characteristics, sources, and assessment of surface water in an industrial mining city, southwest of China.

This study analyzed the physiochemical factors, spatial-seasonal variations, and correlations of main pollutants, water quality evaluation and possible sources of nitrogen in the surface water of Anning, an industrial mining city, southwest of China. Seventy surface water samples were examined through an analysis of 41 physiochemical indices in the dry and wet seasons in April and July 2019, respectively, while a part of water site samples collected in July 2020 was taken for isotope detections. To identify the water quality, single-factor pollution index (SI), Nemerow pollution index (NPI), and water quality comprehensive pollution index (CPI) were calculated based on 13 pollutants using GB 3838-2002 class III water standard values. Results pointed to typical pollutants of TN, TP, and F with ranges of l.d.-44.8 (2.00 ± 3.69) mg/L, l.d.-250 (2.07 ± 15.35) mg/L, and l.d.-11 (1.48 ± 7.34) mg/L respectively with high spatial variability. The concentrations of heavy metals present in the water samples followed the sequence: Zn > Ni > Cu > As > Pb > Cd > Hg, and most of the samples showed low values relative to the standard permissible limits. In three methods, the water quality evaluation results of SI method were obviously worse than NPI and CPI methods. The NPI and CPI values had ranges of 0.116-887.40 (8.12 ± 74.89) and 0.03-111.54 (1.17 ± 9.40), respectively; consequently, the water quality was considered generally well, with more than 65% of sites classified as "cleanness" or "sub-cleanness." Most of the values of δ15N and δ18O had ranges of 6.62-20.05‰ and - 6.53-4.70‰, which suggested the livestock manure resources were the possible sources of nitrogen that entered the surface water causing more pollution in the wet season. Part of sites with serious water pollution had very high concentrations of P, F, or heavy metals and might be closely correlated with the point source pollution of phosphate chemical industry or iron ore mining and smelting. The results of this study can provide the basic data for efficient water management and human health protection for local government.