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Stable isotopes in atmospheric water vapour are important tracers for investigating water vapour transport, mixing and phase transition. In recent years, with the rapid development of analytical techniques, research on water vapour stable isotopes has been widely conducted worldwide. In this review, we summarize basic theory and examine various methodologies employed to study stable isotopes in atmospheric water vapour, ranging from traditional collection methods to more recent advancements in laser absorption spectroscopy, satellite remote sensing, and isotope general circulation models (iGCMs). We pointed out the critical role played by isotopes in tracing moisture sources, understanding precipitation patterns, and reconstructing past climates. We identify gaps in knowledge, particularly in the representation of isotopic processes in climate models. Furthermore, we highlighted future research should focus on enhancing isotopic measurement technologies, integrating isotopic data with climatic indicators to improve model accuracy, and expanding isotopic studies to underserved water cycle dynamics. This review aims to provide suggestions for future investigations to deepen our understanding of atmospheric water vapour stable isotopes and their significance in climatology and hydrology. [ABSTRACT FROM AUTHOR]

This research investigates the quality of water supplied to Bahir Dar city, Ethiopia. The city gets water from 3 springs and 12 dug wells. Fifteen samples were collected from these water sources in the dry and wet seasons and examined according to standard procedures to determine their physicochemical and bacteriological qualities. The mean values of physicochemical parameters (dry and wet seasons) measured include: temperature (26.047 ± 0.71°C and 20.527 ± 0.586°C), pH (7.03 ± 0.58 and 7.13 ± 0.476), electrical conductivity (197 ± 53.78 and 119.144 ± 35.85 μs/cm), total dissolved solid (129.67 ± 34.87 and 70.97 ± 21.48 mg/L), fluoride (0.54 ± 0.263 and 0.21 ± 0.108 mg/L), phosphate (0.544 ± 0.214 and 0.47 ± 0.292 mg/L), nitrate ions (3.16 ± 0.897 and 3.12 ± 1.278 mg/L), total alkalinity (119.22 ± 41.254 and 127.49 ± 32.829 mg/L as CaCO3), and total hardness (47.6 ± 20.797 and 41.47 ± 24.46 mg/L as CaCO3) were safe and within the range of WHO and Ethiopian acceptable drinking water quality standards. The mean turbidity (3.37 ± 3.27 NTU) in the dry season was in the permissible limit of Ethiopia and WHO, but the mean turbidity in the wet season (6.88 ± 2.67 NTU) was above the drinking water guideline of WHO and Ethiopia. The bacteriological analyses of mean fecal coliform (10.6 ± 10.01 and 3.2 ± 2.344 CFU/100 mL) and total coliforms (56.8 ± 74.08 CFU/100 mL, too numerous to count CFU/100 mL) in the dry and wet seasons were beyond the WHO and Ethiopian permissible limit. This indicates that the water sources are not safe and consumers are at risk. Therefore, the water sources require treatment before it is distributed to the consumers. [ABSTRACT FROM AUTHOR]

The increasing challenge of freshwater scarcity amid rising demand and diminishing availability has led to a critical issue threatening sustainable development, especially in rural areas of developing countries like Nigeria. Despite the abundance of studies on rural water use, gaps remain in understanding the interplay between socio-economic factors, and agricultural practices in shaping these preferences and utilisation. Thus, the study investigates the preference for water sources and their utilisation in agricultural activities among rural households in the Akoko district of Ondo State, Nigeria. Cross-sectional data from randomly sampled 240 rural households were collected with the aid of a questionnaire, and employed for the data analysis. Descriptive statistics, logit, and multinomial regressions were used for the data analysis. The findings revealed a dominant preference for rainwater and well water. Factors such as access to safe water sources, time spent, extension service, technology adoption, soil type, experience, and proximity to water sources significantly influence the choice of water source utilization in the area using multinomial logit regression. Again, the results from logit regression revealed that water source, technology adoption, soil type, fish farming, crop farming, farming experience, and distance to water sources significantly affect the use of water for agricultural purposes. Therefore, the policy should enhance water access, consider soil characteristics in agricultural planning, and facilitate knowledge transfer among farmers for optimal water use, recognizing the symbiotic relationship between water access and agricultural sustainability. Article Highlights: Rainwater and well water are the most preferred sources for rural households in agricultural activities. Water source preference is influenced by access, soil type, farming experience, and proximity to water. Improved water access and tailored policies can enhance agricultural productivity and rural livelihoods. [ABSTRACT FROM AUTHOR]

Access to safe drinking water sources and appropriate sanitation facilities remains a dream in low and middle-income countries including South Africa. This study identified the origin of faecal pollution by using quantitative polymerase chain reaction (qPCR) targeting host-specific Bacteroidales genetic markers to track the distribution of human-specific (BacHum) and animal-specific (cattle—BacCow, chicken—Cytb, pig—Pig-2-Bac, dog—BacCan) markers in water sources used by rural communities of the Vhembe District Municipality (VDM). Results revealed the prevalence of BacHum, BacCow, and BacCan in all surface water sources in Thulamela Local Municipality (TLM) and Collins Chabane Local Municipality (CLM) during wet (100%) and dry seasons (50–75%). Cytb was not detected in untreated spring water in TLM and CLM, and Pig-2-Bac was not detected in untreated hand-dug well water in TLM during both seasons. Household-level analysis detected Cytb (28.8% wet, 17.5% dry), BacHum (34.4% wet, 25% dry for Pig-2-Bac) in stored untreated spring water in CLM, and Cytb (42.9% wet, 28.5% dry) in untreated hand-dug well water in TLM. Despite differences in detection frequencies of host-specific Bacteroidales, the study highlights the public health concern of faecal pollution in rural VDM households. [ABSTRACT FROM AUTHOR]

Information on the detection of the presence and potential for degradation of synthetic polymers (SPs) under various environmental conditions is of increasing interest and concern to a wide range of specialists. At this stage, there is a need to understand the relationship between the main participants in the processes of (bio)degradation of SPs in various ecosystems (reservoirs with fresh and sea water, soils, etc.), namely the polymers themselves, the cells of microorganisms (MOs) participating in their degradation, and humic substances (HSs). HSs constitute a macrocomponent of natural non-living organic matter of aquatic and soil ecosystems, formed and transformed in the processes of mineralization of bio-organic substances in environmental conditions. Analysis of the main mechanisms of their influence on each other and the effects produced that accelerate or inhibit polymer degradation can create the basis for scientifically based approaches to the most effective solution to the problem of degradation of SPs, including in the form of microplastics. This review is aimed at comparing various aspects of interactions of SPs, MOs, and HSs in laboratory experiments (in vitro) and environmental investigations (in situ) aimed at the biodegradation of polymers, as well as pollutants (antibiotics and pesticides) that they absorb. Comparative calculations of the degradation velocity of different SPs in different environments are presented. A special place in the analysis is given to the elemental chemical composition of HSs, which are most successfully involved in the biodegradation of SPs. In addition, the role of photo-oxidation and photoaging of polymers under the influence of the ultraviolet spectrum of solar radiation under environmental conditions on the (bio)degradation of SPs in the presence of HSs is discussed. [ABSTRACT FROM AUTHOR]

Abstract The increasing challenge of freshwater scarcity amid rising demand and diminishing availability has led to a critical issue threatening sustainable development, especially in rural areas of developing countries like Nigeria. Despite the abundance of studies on rural water use, gaps remain in understanding the interplay between socio-economic factors, and agricultural practices in shaping these preferences and utilisation. Thus, the study investigates the preference for water sources and their utilisation in agricultural activities among rural households in the Akoko district of Ondo State, Nigeria. Cross-sectional data from randomly sampled 240 rural households were collected with the aid of a questionnaire, and employed for the data analysis. Descriptive statistics, logit, and multinomial regressions were used for the data analysis. The findings revealed a dominant preference for rainwater and well water. Factors such as access to safe water sources, time spent, extension service, technology adoption, soil type, experience, and proximity to water sources significantly influence the choice of water source utilization in the area using multinomial logit regression. Again, the results from logit regression revealed that water source, technology adoption, soil type, fish farming, crop farming, farming experience, and distance to water sources significantly affect the use of water for agricultural purposes. Therefore, the policy should enhance water access, consider soil characteristics in agricultural planning, and facilitate knowledge transfer among farmers for optimal water use, recognizing the symbiotic relationship between water access and agricultural sustainability.

Abstract Access to safe drinking water sources and appropriate sanitation facilities remains a dream in low and middle-income countries including South Africa. This study identified the origin of faecal pollution by using quantitative polymerase chain reaction (qPCR) targeting host-specific Bacteroidales genetic markers to track the distribution of human-specific (BacHum) and animal-specific (cattle—BacCow, chicken—Cytb, pig—Pig-2-Bac, dog—BacCan) markers in water sources used by rural communities of the Vhembe District Municipality (VDM). Results revealed the prevalence of BacHum, BacCow, and BacCan in all surface water sources in Thulamela Local Municipality (TLM) and Collins Chabane Local Municipality (CLM) during wet (100%) and dry seasons (50–75%). Cytb was not detected in untreated spring water in TLM and CLM, and Pig-2-Bac was not detected in untreated hand-dug well water in TLM during both seasons. Household-level analysis detected Cytb (28.8% wet, 17.5% dry), BacHum (34.4% wet, 25% dry for Pig-2-Bac) in stored untreated spring water in CLM, and Cytb (42.9% wet, 28.5% dry) in untreated hand-dug well water in TLM. Despite differences in detection frequencies of host-specific Bacteroidales, the study highlights the public health concern of faecal pollution in rural VDM households.

Urbanization changes wildlife habitats and affects the reproduction and survival of animal populations. Investigating the breeding habitat selection of species in highly urbanized areas is essential for understanding the impact of urbanization on biodiversity. Common Magpie (Pica pica) is a common bird species in both urban and rural areas. Furthermore, it is an ideal candidate for studying the ecological effects of urbanization on the nest habitat selection of birds, because of its large quantity and easily observable nests. In this study, Hefei city was divided into peripheral rural area, edge region of urban expansion, slightly urbanized area, and highly urbanized area according to the coverage rate of buildings within kilometer grid units, comprising a total of 240 sample plots. A total of 60 sample plots were randomly selected in each of the four types of urbanization grades to investigate the number of Common Magpie nests, nest species, and nest sites. The Kruskal-Wallis rank sum test method was used to analyze the habitat characteristics of 692 Common Magpie nests, and the differences in the main habitat factors of Common Magpie nest sites in different urbanization levels were obtained by multiple Wilcoxon tests. The results showed that the number of Common Magpie nests in highly urbanized areas (16.33%) was lower than that in other areas, whereas the number of nests edge region of urban expansion was relatively high (37.14%). Tree species of Common Magpie nests were diverse (25 species), and Salicaceae trees accounted for a certain proportion. Except for tree coverage (χ² =5.069, P=0.167), there were significant differences in nest site and habitat factors among the four types of plots with different urbanization levels. Common Magpie nests in highly urbanized areas with higher human disturbance intensity were closer to food sources and farther from water sources, while the nests in rural area outside cities with lower level of urbanization were the opposite. [ABSTRACT FROM AUTHOR]

The objective of this paper is to evaluate the economic use of different water sources in the culture of the African Catfish (Clarias gariepinus; Burchell 1822) at Ediba-Qua, Calabar, Cross River State, Nigeria using standard appropriate techniques. Results obtained showed that cost of feeding increased significantly at (p < 0.05) with growth rate and weight gain in fish reared in borehole water having the highest cost (₦ 21617.86 ± 31.77) and least in rainwater (₦ 13635.93 ± 48.16). Profit index was highest in C. gariepinus reared in borehole water (16.99 ± 0.70), and least in stream water (15.74 ± 0.42) indicating that borehole water is the best water source for C. gariepinus with regards to profitability. This study has shown that fish farmers and fish intending farmers who are challenged by borehole water supply for fish culture can alternatively harvest rainwater or collect stream water to rear fish that could be utilized at a subsistent level. [ABSTRACT FROM AUTHOR]

Access to safe drinking water sources and appropriate sanitation facilities remains a dream in low and middle-income countries including South Africa. This study identified the origin of faecal pollution by using quantitative polymerase chain reaction (qPCR) targeting host-specific Bacteroidales genetic markers to track the distribution of human-specific (BacHum) and animal-specific (cattle—BacCow, chicken—Cytb, pig—Pig-2-Bac, dog—BacCan) markers in water sources used by rural communities of the Vhembe District Municipality (VDM). Results revealed the prevalence of BacHum, BacCow, and BacCan in all surface water sources in Thulamela Local Municipality (TLM) and Collins Chabane Local Municipality (CLM) during wet (100%) and dry seasons (50–75%). Cytb was not detected in untreated spring water in TLM and CLM, and Pig-2-Bac was not detected in untreated hand-dug well water in TLM during both seasons. Household-level analysis detected Cytb (28.8% wet, 17.5% dry), BacHum (34.4% wet, 25% dry for Pig-2-Bac) in stored untreated spring water in CLM, and Cytb (42.9% wet, 28.5% dry) in untreated hand-dug well water in TLM. Despite differences in detection frequencies of host-specific Bacteroidales, the study highlights the public health concern of faecal pollution in rural VDM households. [ABSTRACT FROM AUTHOR]

Introduction: The precipitation pattern has changed significantly in arid desert areas, yet it is not clear how the water use strategies of Tamarix ramosissima Ledeb. on coppice dunes along a natural precipitation gradient are affected. Methods: In this study, the hydrogen and oxygen isotope compositions of xylem water, soil water, precipitation, and groundwater were measured by stable isotope techniques in Huocheng, Mosuowan, and Tazhong. Additionally, the water use strategies of natural precipitation gradient were investigated in conjunction with the MixSIAR model. Results: The results indicated that the water sources of T. ramosissima exhibited significant variation from semi-arid to hyper-arid areas. In semi-arid areas, T. ramosissima mainly absorbed shallow, shallow-middle, and middle soil water; however, T. ramosissima shifted its primary water sources to middle and deep soil water in arid areas. In hyper-arid areas, it mainly utilized deep soil water and groundwater. In contrast, the water source contribution rate of T. ramosissima exhibited relative uniformity across each layer in an arid area. Notably, in hyper-arid areas, the proportion of groundwater by T. ramosissima was significantly high, reaching 60.2%. This is due to the relatively shallow groundwater supplementing the deep soil water content in the area. In conclusion, the proportion of shallow soil water decreased by 14.7% for T. ramosissima from semi-arid to hyper-arid areas, illustrating the occurrence of a gradual shift in potential water sources utilized by T. ramosissima from shallow to deep soil water and groundwater. Discussion: Therefore, T. ramosissima on coppice dunes shows flexible water use strategies in relation to precipitation and groundwater, reflecting its strong environmental adaptability. The findings hold significant implications for the conservation of water resources and vegetation restoration in arid areas. [ABSTRACT FROM AUTHOR]

Irrigation water quality is crucial in maintaining soil health and productivity, particularly in semi-arid regions where agriculture heavily relies on irrigation. This study aimed to assess the impact of different irrigation water sources (groundwater, canal water, and treated and disinfected sewage water) on soil quality in rice fields in Kurukshetra, Haryana, India. Water and soil samples were collected from rice fields irrigated with each water source and analyzed for various physicochemical parameters. The results revealed significant differences in irrigation water quality, with STP exhibiting higher salinity levels, as indicated by elevated electrical conductivity (EC), total dissolved solids (TDS), sodium, chloride, and sulphate concentrations. Soil quality parameters also varied significantly among rice fields irrigated with different water sources. Rice fields irrigated with STP had higher soil EC and higher concentration cations and anions along with organic carbon content potentially due to the contribution of organic load and nutrients from sewage treatment plants. It was inferred from the study that disinfected sewage effluent has the potential to be used in irrigation, provided that regular monitoring is done. The findings highlight the importance of considering irrigation water quality in agricultural practices and the need for appropriate water management strategies to maintain soil quality and ensure sustainable rice production in the region. [ABSTRACT FROM AUTHOR]

The summer of 2019 is particularly well known for the famous heatwaves that swept across the European continent, with its associated drought and record-breaking air temperatures. This was followed by powerful thunderstorms, characterised by hail and heavy rain that damaged the crops on a regional scale. Here, we investigated one of the largest storm cells, lasting more than 6 h, which struck southwestern Romania. High-temporal resolution sampling of storm precipitation was performed for stable isotope measurements, rainfall and air temperature, to follow the storm dynamics. Hydrogen and oxygen isotope measurements show an abrupt decreasing temporal trend followed by superimposed V-shaped patterns interpreted as reflecting moisture replenishment by successive rain bands. To model the stable isotope values of precipitation in relation to the general trend of decreasing air temperatures, we applied a numerical Rayleigh condensation model for a non-constant α isotopic fractionation factor between liquid water and water vapour. The storm is powered by four consecutive moisture fronts, each following a Rayleigh distribution. About 40 % of the water vapour condenses during the sampled storm due to adiabatic expansion and cooling, which lowers saturation. Condensation ceases when cooling and absolute humidity can no longer sustain the dew point, stopping the rain. The timing of the event, occurring late at night and early in the morning, its duration of over 6 h as well as its synoptic scale may indicate a mesoscale convective complex. [ABSTRACT FROM AUTHOR]

A safe water supply is a necessity, but it remains one of the backlogs of services rendered in rural areas of developing countries. This leads to vulnerable communities using water from available sources that is unsafe as it is contaminated with faecal matter. Microbial source tracking (MST) methods are gold-standard techniques that detect the exact sources of faecal contamination. This study, therefore, tracked and identified the exact sources of faecal contamination from the catchment to the point of use in rural areas of Vhembe District Municipality. Collected water samples (n = 1048) were concentrated by membrane filtration for the enumeration and detection of E. coli, followed by DNA extraction. The extracted DNA was subjected to a quantitative polymerase chain reaction (qPCR) to track target host-specific Bacteroidales genetic markers from the water source to the point of use. Rivers and dams exhibited maximum E. coli counts of up to 90 CFU/100 mL during the wet season and up to 50 CFU/100 mL during the dry season. Due to the effective treatment of these water sources, no E. coli bacteria were detected in any of the sampled municipal drinking water treatment plants at the point of treatment, while this indicator bacterium was detected at the point of use (households), with a maximum of 4 CFU/100 mL recorded during both the wet and dry seasons. Overall, the most prevalent MST marker exhibited during the wet season was BacCan (dog-associated, 6.87%), followed by BacCow (cow-associated, 5.53%), while Pig-2-Bac (pig-associated, 2.48%) was the least prevalent. The most prevalent marker exhibited during the dry season was BacCan (5.34%), followed by BacCow, with Pig-2-Bac (1.72%) being the least prevalent. A positive correlation (r = 0.31, p = 0.001) was established between the presence of the MST markers and detected E. coli from water sources to the point of use. The knowledge of the faecal contamination attributes in both public and domestic domains will assist in developing prevention and control strategies. [ABSTRACT FROM AUTHOR]

The occurrence of high levels of heavy metals in drinking water is a significant health concern due to the accompanying health concerns. Hence, the objective of this study was to evaluate the bacterial species and concentration of heavy metals in certain drinking water sources in Ikwo, Ebonyi State. Nigeria. The analysis of metal concentration revealed that the levels of lead, iron, and mercury in the water exceeded the established limits for drinking water quality set by the World Health Organisation (WHO) and Nigeria standard for drinking water quality (NSDWQ). However, the concentrations of copper, zinc, calcium, and sodium in the water were not statistically significant (P >0.05). The bacteriological count results indicated that the average Total Bacterial Count (TBC) in water samples collected from ponds, rivers, and wells were 5.10 x 10-4, 6.10 x 10-3, and 4.10 x 10-4, respectively. During the experiment, there was a notable disparity (p <0.05) in the bacterial quantities seen in all of the samples. Escherichia coli was the predominant strain, representing 70% of all isolates, as indicated by prevalence surveys. Salmonella and Klebsiella species accounted for 25% and 39% of isolates, respectively. Research on antibiotics discovered that Salmonella, Klebsiella species, and E. coli exhibited significant resistance to popular antibiotics, albeit showing some vulnerability to some ones. The presence of antibiotic resistant microbes in drinking water samples from the research region is a significant public health concern due to the high probability of contracting waterborne illnesses and the associated health hazards. This is particularly worrisome for the immune-compromised residents of the area. [ABSTRACT FROM AUTHOR]

The overuse of pesticides in agriculture poses significant threats to human health and the environment. This study addresses the issue by proposing a hybrid multi‐criteria decision‐making (MCDM) method, utilizing the analytic hierarchy process (AHP), to select the most suitable pesticide removal method for drinking water treatment. Focusing on the priority and selection of treatment options for specific pesticide groups, such as diuron and cypermethrin, based on toxicity and physicochemical properties, the study concludes that nanofiltration is best option for diuron removal, while granular activated carbon adsorption is effective for cypermethrin. The innovative hybrid MCDM (AHP + TOPSIS and AHP + VIKOR) approach, unprecedented in assessing pesticide removal methods for drinking water treatment, proves promising in ranking treatment processes for pesticides. The study emphasizes the serious consequences of excessive pesticide use, highlights treatment solutions like NF and GAC adsorption, and introduces cutting‐edge hybrid MCDM techniques for selection treatment process that meet technical, economical, and environmental requirements. All of these factors combine to provide a novel approach not only used to select the best option from alternatives, but also to prioritize alternative processes in drinking water treatment at pesticide removal practices. [ABSTRACT FROM AUTHOR]

ABSTRACT Environmental monitoring of water is essential for efficient management of water source conservation in river basins. However, there is a lack of studies with this synergy applying unconventional techniques. We evaluated chemical characteristics of surface and underground waters (2021-2022), including for the first time the analysis of the isotopic composition of waters collected from water sources throughout Educandos`s Basin, in the city of Manaus-AM/Brazil, to evaluate chemical-isotopic changes in the view of anthropogenic impacts. Statistical analyzes were used to compare means, graphical analyzes and Principal Component Analysis to identify the main patterns of the data sets. Our results demonstrated a significant increase in pH, electrical conductivity and an increased in nitrates in polluted groundwater and reduced DO in contaminated surface waters. Furthermore, the isotopic signature did not indicate pollution through changes in the isotopic composition of natural and polluted waters, however, it showed more depleted signatures in one of the underground monitoring wells, indicating an impact site vulnerable to the interaction of aquifer waters with Rio Negro and Igarapé. When analyzing chemical parameters with isotopic composition, it can be allowed a better understanding of the mechanisms of circulation and mineralization of underground and surface waters in the Urban Hydrographic Basin.

Health authorities are particularly concerned about water security in Enugu, southeast Nigeria and heavy metal (HM) pollution. The HM profiles of 51 samples collected from 17 different commercial bottled water brands in Enugu were examined using an flame atomic absorption spectroscopy. Cd, Cr, Cu, Pb, Ni, and Zn had mean values of 0.15 ± 0.03, 0.03 ± 0.02, 0.16 ± 0.03, 0.13 ± 0.02, and 0.02 ± 0.01 mg/L, respectively. The highest levels of Pb2+ were 0.27 mg/L in Exalté, Ni2+ 0.26 mg/L in Jasmine, Cd2+ 0.36 mg/L in Ezbon, Cr3+ 0.07 mg/L in Trinity, Cu2+ 0.04 mg/L in Bigi, and Zn2+ 0.02 mg/L in Aquarapha. The amounts of Cr, Cu, and Zn were below the allowable limits; nevertheless, the Pb content in eight bottled water samples exceeded both the Nigerian and World Health Organization (WHO)/U.S. Environmental Protection Agency (USEPA) permissible limits. The Cd2+ and Ni2+ levels in the 11th and 4th bottled water samples were above the WHO/USEPA-approved limits. Statistical evaluation revealed significant differences in the amounts of HM ions in the samples (p < 0.05). The findings indicated that concentration levels of Cd2+ Ni2+, and Pb2+ pose a public health concern that needs to be addressed due to potential risk to consumer health. HIGHLIGHTS Pb detected in the remaining nine samples and exceeded the allowable limits set by the World Health Organization (WHO) and U.S. Environmental Protection Agency (USEPA).; Cd2+ was found in 11 bottled water samples, all of which were above the WHO and USEPA acceptable limits.; The result (dendrogram) showed five clusters, with Cu being more related to Zn than to Pd, Ni, Cd, and Cr.; The use of nanofiltration and microfiltration is known to remove hexavalent chromium (Cr(VI)).;

Access to safe drinking water remains a fundamental issue in rural areas of Ethiopia. This study aimed to evaluate the physicochemical and bacteriological quality of drinking water at protected sources in the Farta district, South Gondar Zone, Ethiopia. The study covered 16 rural Kebeles and was conducted on 75 protected dug wells with hand pumps (HDWs) and 17 protected springs (PSs). Data were collected during the wet and dry season, and field measurement were conducted on water samples pH, turbidity, electrical conductivity, and temperature, while laboratory analysis focused on E. coli prevalence. Additionally, sanitary risk assessment was also performed. The result showed that, the pH values ranged from 5.4 to 8.1, turbidity levels varied between 0 to 100 nephelometric turbidity unit (NTU), electric conductivity ranged from 62 to 584 µS/cm, and temperature ranged from 12.1 to 27 °C. Among all the samples, 39.1% had a pH below the minimum standard value of 6.5, close to 50.5% did not meet the turbidity requirement (5NTU), and all samples were safe against electric conductivity levels. The E. coli contamination was widespread, and only a small percentage of water sources, such as 21.7% HDWs, 6.7% PSs during dry season, and 13% HDWs during wet season were negative to E. coli detection. A significant proportion of water sources, such as 18% HDWs and 13% PSs during dry season, as well as 44.9% HDWs and 46.7% PSs during wet season, fell into the high microbial health risk category. Sanitary inspections revealed that only 16.7% of water sources were classified as low sanitary risk. This study revealed that majority of water sources were unfit to drinking and may endanger the public health. To ensure safe water availability frequent cleaning and disinfection of water sources, implementation of household water treatment, and improvement of WASH (water, sanitation and hygiene) infrastructure is needed. [ABSTRACT FROM AUTHOR]

Luan River is the main water source in Beijing-Tianjin-Hebei region, northern China, where the groundwater system is vulnerable and pollution issue is serious. It is significant for regional groundwater resources protection to identify the hydrogeochemistry evolution and affecting factors along flow direction occurred in the upper reaches, especially the surface water-groundwater (SW-GW) conversion relationship. In this study, recharge, conversion and geochemistry evolution of SW and GW were elucidated based on physical-hydrochemical indicators and stable isotopes in 36 GW samples and 20 SW samples, which were collected in July 2019 and July 2020. The factor analysis was further utilized to determine the main factors responsible for regional hydrogeochemical evolution. Results indicate that GW recharged SW in plateau area, and SW and GW recharged each other in typical Alpine valley area. The hydrochemical types are HCO3−Ca·Mg and HCO3-Ca, and the hydrochemical evolution is dominated by weathering of silicate and carbonate minerals. The cation exchange adsorption has minor impact on groundwater hydrochemistry. The rise of SO42− and NO3− contents in groundwater is related to industrial and agricultural activities. The main controlling factors of SW hydrochemical components included recharge from groundwater, industrial and mining activities, explaining 90.04% of data variance. However, water-rock interaction, agricultural and domestic sewage are responsible for GW quality, accounting for 83.38%. [ABSTRACT FROM AUTHOR]

Health authorities are particularly concerned about water security in Enugu, southeast Nigeria and heavy metal (HM) pollution. The HM profiles of 51 samples collected from 17 different commercial bottled water brands in Enugu were examined using an flame atomic absorption spectroscopy. Cd, Cr, Cu, Pb, Ni, and Zn had mean values of 0.15+0.03, 0.03+0.02, 0.16+0.03, 0.13+0.02, and 0.02+0.01 mg/L, respectively. The highest levels of Pb2+ were 0.27 mg/L in Exalté, Ni2+ 0.26 mg/L in Jasmine, Cd2+ 0.36 mg/L in Ezbon, Cr3+ 0.07 mg/L in Trinity, Cu2+ 0.04 mg/L in Bigi, and Zn2+ 0.02 mg/L in Aquarapha. The amounts of Cr, Cu, and Zn were below the allowable limits; nevertheless, the Pb content in eight bottled water samples exceeded both the Nigerian and World Health Organization (WHO)/U.S. Environmental Protection Agency (USEPA) permissible limits. The Cd2+ and Ni2+ levels in the 11th and 4th bottled water samples were above the WHO/USEPAapproved limits. Statistical evaluation revealed significant differences in the amounts of HM ions in the samples (p,0.05). The findings indicated that concentration levels of Cd2+ Ni2+, and Pb2+ pose a public health concern that needs to be addressed due to potential risk to consumer health. [ABSTRACT FROM AUTHOR]

We investigated the stable isotope hydrology of Sable Island, Nova Scotia, Canada over a five year period from September, 2017 to August, 2022. The δ2H and δ18O values of integrated monthly precipitation were weakly seasonal and ranged from –66 to –15 ‰ and from –9.7 to –1.9 ‰, respectively. Fitting these monthly precipitation data resulted in a local meteoric water line (LMWL) defined by: δ2H = 7.22 ± 0.21 · δ18O + 7.50 ± 1.22 ‰. Amount-weighted annual precipitation had δ2H and δ18O values of –36 ± 11 ‰ and –6.1 ± 1.4 ‰, respectively. Deep groundwater had more negative δ2H and δ18O values than mean annual precipitation, suggesting recharge occurs mainly in the winter, while shallow groundwater had δ2H and δ18O values more consistent with mean annual precipitation or mixing of freshwater with local seawater. Surface waters had more positive values and showed evidence of isolation from the groundwater system. The stable isotopic compositions of plant (leaf) water, on the other hand, indicate plants use groundwater as their source. Fog had δ2H and δ18O values that were significantly more positive than those of local precipitation, yet had similar 17O-excess values. δ2H values of horsehair from 4 individuals lacked seasonality, but had variations typical to those of precipitation on the island. Differences in mean δ2H values of horsehair were statistically significant and suggest variations in water use may exist between spatially disparate horse communities. Our results establish an important initial framework for ongoing isotope studies of feral horses and other wildlife on Sable Island. [ABSTRACT FROM AUTHOR]

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The objective of this paper is to evaluate the economic use of different water sources in the culture of the African Catfish (Clarias gariepinus; Burchell 1822) at Ediba-Qua, Calabar, Cross River State, Nigeria using standard appropriate techniques. Results obtained showed that cost of feeding increased significantly at (p < 0.05) with growth rate and weight gain in fish reared in borehole water having the highest cost (₦ 21617.86 ± 31.77) and least in rainwater (₦ 13635.93 ± 48.16). Profit index was highest in C. gariepinus reared in borehole water (16.99 ± 0.70), and least in stream water (15.74 ± 0.42) indicating that borehole water is the best water source for C. gariepinus with regards to profitability. This study has shown that fish farmers and fish intending farmers who are challenged by borehole water supply for fish culture can alternatively harvest rainwater or collect stream water to rear fish that could be utilized at a subsistent level.

Springs and streams are vital water sources for supporting the livelihood of Himalayan residents. Escalating climate change, population growth, and economic development strain the region's freshwater resources. A national survey reveals declining spring and stream flows in Bhutan, necessitating an improved understanding of their generation. Monthly grab water samples were collected during April 2022–January 2023 from main streams, springs and other source waters at various elevations at Yude Ri and Dungju Ri catchments, Bhutan Himalayas. Samples were analyzed for pH, specific conductance, and major ions and end-member mixing analysis in combination with diagnostic tools of mixing models was used to determine sources, relative contributions, and recharge dynamics of spring flows. The results indicated that direct precipitation dominated spring flows (0.59 ± 0.21), followed by shallow groundwater (0.31 ± 0.18), and soil subsurface water (0.10 ± 0.15). The contributions of spring flow components followed an elevation gradient, with higher and lower fractions, respectively, of direct precipitation and shallow groundwater at higher elevations, e.g., 0.90 ± 0.1 to 0.13 ± 0.08 for direct precipitation and 0.03 ± 0.03 to 0.37 ± 0.19 for shallow groundwater from 3266 m to 1558 m. Spring flows primarily relied on precipitation (∼70 % from both direct precipitation and soil water), making them very sensitive to changes in precipitation. Significant contributions of shallow groundwater also indicated the vulnerability of spring flows to decreased snowfall relative to rainfall and the earlier onset of snowmelt, particularly for those located in the snow-rain transition zone (∼2500 m). Our results suggest high vulnerability of spring flows to the climate change in the Himalayas.

The occurrence of high levels of heavy metals in drinking water is a significant health concern due to the accompanying health concerns. Hence, the objective of this study was to evaluate the bacterial species and concentration of heavy metals in certain drinking water sources in Ikwo, Ebonyi State. Nigeria. The analysis of metal concentration revealed that the levels of lead, iron, and mercury in the water exceeded the established limits for drinking water quality set by the World Health Organisation (WHO) and Nigeria standard for drinking water quality (NSDWQ). However, the concentrations of copper, zinc, calcium, and sodium in the water were not statistically significant (P >0.05). The bacteriological count results indicated that the average Total Bacterial Count (TBC) in water samples collected from ponds, rivers, and wells were 5.10 x 10-4, 6.10 x 10-3, and 4.10 x 10-4, respectively. During the experiment, there was a notable disparity (p

Abstract Drinking water contaminated by pathogenic micro-organisms increases the risk of infectious gastrointestinal disease which could potentially lead to acute kidney injury and even death, particularly amongst the young and the elderly. Earlier studies have shown a substantial reduction in the incidence of diarrheal disease over a period of one year using a polysulfone membrane water gravity-powered water filtration device. The current report is a continuation of these studies to assess the long-term effects of the innovative method on diarrheal incidence rates over a 4-year follow-up period. This follow-up study monitored the trend of self-reported diarrheal events in all households in the previously studied villages for 5 months, in the last half of each study year, using the same questionnaire utilized in the earlier study. Three villages that had no device yet installed served as controls. We computed monthly diarrheal incidence rates for all study years (standardized to per 100 person-months) and compared these to the pre-device incidence rate in 2018 and in the control group, using the Wilcoxon rank sum exact test. The average diarrheal incidence rates of 1.5 p100pm in 2019, 2.19 p100pm in 2021, and 0.54p100pm in 2022 were significantly different from an earlier study that reported 17.8 p100pm rates before the devices were installed in 2018, (all p-values

The current study proposes an effective machine learning model based on a stacked generalisation technique for predicting arsenic content in water sources (groundwater, surface water and drinking water) based on physicochemical water parameters (turbidity, pH, electrical conductivity and total suspended solids). In the proposed approach, random forest and decision trees were stacked as base regressors in the first layer. Then, extreme gradient boosting was employed as a meta-regressor in the second layer to compute the final predictions. A comprehensive assessment of the proposed approach was performed using reliable statistical metrics and diagnostic plots of the observed and predicted arsenic concentration. The results demonstrated a better generalisation performance of the proposed stacked approach as compared with the standalone models of decision trees, random forest, extreme gradient boosting, generalised regression neural network, light gradient boosting, multi-layer perceptron, multivariate adaptive regression splines and other stacked variants models. The proposed stacked approach outperformed all comparative models by achieving the lowest RMSE and MAPE of 8.041E-04 and 0.4689, respectively, and the highest NSE and R2 of 0.9778 and 0.9787, respectively. Overall, the results have indicated that the proposed stacked generalisation performance is very sensitive to the choice of base learners. The outcome of this study indicates that a stronger predictive potential of base learners could lead to higher performance of the overall stacking model. Hence, the proposed approach could be principal in predicting arsenic concentration in water sources. [ABSTRACT FROM AUTHOR]

Calligonum mongolicum is often planted as a windbreak and for sand stabilization on mobile and semi‐mobile sand dunes in extremely arid regions. However, water availability remains a key limiting factor for its survival and population expansion, and water use strategies and responses to precipitation events of this species are unknown. Here, we determined water use strategy of C. mongolicum under extreme arid conditions by measuring the oxygen stable isotopes (δD and δ18O) in xylem water and in potential water sources (precipitation, soil water, and groundwater). We used the IsoSource model to determine the relative contributions of different water sources to water utilization by C. mongolicum. Our results showed that: (1) water sources used by C. mongolicum exhibited seasonal variability, with shallow soil water accounting for 42% of utilization during early spring (April), and deep soil water and groundwater being predominantly used during the summer and autumn and accounting for 61%–84% of utilization, (2) C. mongolicum did not respond to small precipitation events, but responded significantly to large precipitation events. C. mongolicum maintained the utilization of soil water in all layers at 74%–81% of deep soil water and groundwater before a 5.8 mm precipitation event. A precipitation event of 18.8 mm increased the contribution of surface water from 4% before to 17% after precipitation, indicating that C. mongolicum has a strong capacity for self‐regulation and adaptation; namely, C. mongolicum is capable of developing an optimal phenotype through self‐regulation, thereby maximizing water acquisition. [ABSTRACT FROM AUTHOR]

Plants have always represented a key element in landscape delineation. Indeed, plant diversity, whose distribution is influenced by geographic/climatic variability, has affected both environmental and human ecology. The present contribution represents a multi‐proxy study focused on the detection of starch, pollen and non‐pollen palynomorphs in ancient dental calculus collected from pre‐historical individuals buried at La Sassa and Pila archaeological sites (Central Italy). The collected record suggested the potential use of plant taxa by the people living in Central Italy during the Copper‐Middle Bronze Age and expanded the body of evidence reported by previous palynological and palaeoecological studies. The application of a microscopic approach provided information about domesticated crops and/or gathered wild plants and inferred considerations on ancient environments, water sources, and past health and diseases. Moreover, the research supplied data to define the natural resources (e.g., C4‐plant intake) and the social use of the space during that period. Another important aspect was the finding of plant clues referable to woody habitats, characterised by broad‐leaved deciduous taxa and generally indicative of a warm‐temperate climate and grassy vegetation. Other unusual records (e.g., diatoms, brachysclereids) participated in defining the prehistoric ecological framework. Thus, this work provides an overview on the potential of the human dental calculus analysis to delineate some features of the ancient plant ecology and biodiversity. [ABSTRACT FROM AUTHOR]

The Hutuo River Drinking Water Source Area is an important water source of Shijiazhuang (North China Plain). Knowing the characteristics of groundwater chemistry/quality is essential for the protection and management of water resources. However, there are few studies focused on the groundwater chemistry evolution over the drinking water area. In this study, total of 160 groundwater samples were collected in November 2021, and the spatial distribution of groundwater chemistry and related controlling factors were analyzed using hydrological and multivariate analysis. The entropy-weighted water quality index (EWQI) was introduced to assess the groundwater quality. The results show that the hydrogeochemical types of groundwater are Ca-HCO3 (78.1%), mixed Ca-Mg-Cl (20%), and Ca-Cl (1.9%) in the area. Graphical and binary diagrams indicate that groundwater hydrochemistry is mainly controlled by water–rock interaction (i.e., rock weathering, mineral dissolution, and ion exchange). Five principal components separated from the principal component analysis represent the rock–water interaction and agricultural return, redox environment, geogenic sources, the utilization of agricultural fertilizer, the weathering of aluminum silicates, and dissolution of carbonates, respectively. More than 70% of the samples are not recommended for irrigation due to the presence of high salt content in groundwater. EWQI assessment demonstrates that the quality of the groundwater is good. The outcomes of this study are significant for understanding the geochemical status of the groundwater in the Hutuo River Drinking Water Source Area, and helping policymakers to protect and manage the groundwater. [ABSTRACT FROM AUTHOR]

Dichlorodiphenyltrichloroethane (DDT) usage has been prohibited in developed nations since 1972 but is exempted for use in indoor residual spraying (IRS) in developing countries, including African countries, for malaria control. There have been no previous reviews on DDT residues in water resources in Africa. The study aimed to provide a review of available research investigating the levels of DDT residues in water sources in Africa and to assess the consequent human health risks. A scoping review of published studies in Africa was conducted through a systematic electronic search using PubMed, Web of Science, EBSCO HOST, and Scopus. A total of 24 articles were eligible and reviewed. Concentrations of DDT ranged from non-detectable levels to 81.2 μg/L. In 35% of the studies, DDT concentrations surpassed the World Health Organization (WHO) drinking water guideline of 1 μg/L in the sampled water sources. The highest DDT concentrations were found in South Africa (81.2 μg/L) and Egypt (5.62 μg/L). DDT residues were detected throughout the year in African water systems, but levels were found to be higher during the wet season. Moreover, water from taps, rivers, reservoirs, estuaries, wells, and boreholes containing DDT residues was used as drinking water. Seven studies conducted health risk assessments, with two studies identifying cancer risk values surpassing permissible thresholds in water sampled from sources designated for potable use. Non-carcinogenic health risks in the studies fell below a hazard quotient of 1. Consequently, discernible evidence of risks to human health surfaced, given that the concentration of DDT residues surpassed either the WHO drinking water guidelines or the permissible limits for cancer risk in sampled drinking sources within African water systems. Therefore, alternative methods for malaria vector control should be investigated and applied.

A study of the quality of drinking water sources - surface waters of the river systems of the city of Latacunga and the canton of Pedro Vicente Maldonado, Ecuador, was carried out during 2018 and 2019. The general sanitary water quality index (WQI) was calculated according to Russian methods, the water quality index of the National Sanitation Foundation (NSF-WQI) of the Ecuadorian water quality regulation. Results from parameterizing the water quality, obtained by WQI and NSF-WQI methods and combined into an overall scheme, were used to generate the rating scale for assessing the hydro-ecological status of aquatic ecosystems. When carrying out a qualitative and quantitative analysis of water from river reservoirs, the excess of the threshold limit values of such indicators as the biological oxygen demand and iron was determined. The calculations show that the WQI method and the NSF-WQI method lead to similar results when assessing the water quality of both reservoir of the city of Latacunga and canton of Pedro Vicente Maldonado. According to the WQI method, the hydrological state of the reservoir of the city of Latacunga was characterized in the range of a scale from “Crisis” to “Risk”, while according to the NSF-WQI method the state was assessed as “Risk”. The hydrological state of the reservoir of the canton of Pedro Vicente Maldonado, was assessed as “Risk” by both the WQI method and the NSF-WQI method. Furthermore, in none of the water bodies under study is the environmental “catastrophe” not recorded.

This study examines the impact of irrigation water quality on the synthesis of secondary metabolites and the chemical composition of Mentha piperita essential oil (MPEO). Three essential oils from Mentha piperita plants, irrigated with different water sources commonly used for mint irrigation in Morocco’s Oriental region, were analyzed. The water sources were characterized based on various parameters, such as nitrites, nitrates, orthophosphates, chemical oxygen demand (COD), biological oxygen demand (BOD5), pH, and electrical conductivity. The essential oils were extracted using hydrodistillation, and their chemical composition was determined using gas chromatography coupled with mass spectrometry (GC/MS), revealing notable variations among the compositions of the three essential oils. In this study, in silico tests using the Prediction of Activity Spectra for Substances (PASS) algorithm; the absorption, distribution, metabolism, and excretion (ADME) model; and Pro-Tox II were conducted to evaluate the drug-likeness, pharmacokinetic properties, expected safety profile upon ingestion, and potential pharmacological activity of the identified compounds in MPEO. The antioxidant activity of the MPEOs was assessed through a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and the total antioxidant activity (TAC) method. Additionally, the antimicrobial effectiveness of the essential oils was tested against four bacterial strains (Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa) and four fungal strains (Candida glabrata, Rhodotorula glutinis, Penicillium digitatum, Aspergillus niger), demonstrating moderate to strong activities against the tested strains. This study concludes that regulating irrigation water quality can enhance the production of specific metabolites, making them potentially valuable as antioxidants and antimicrobial agents.

Abstract Plants have always represented a key element in landscape delineation. Indeed, plant diversity, whose distribution is influenced by geographic/climatic variability, has affected both environmental and human ecology. The present contribution represents a multi‐proxy study focused on the detection of starch, pollen and non‐pollen palynomorphs in ancient dental calculus collected from pre‐historical individuals buried at La Sassa and Pila archaeological sites (Central Italy). The collected record suggested the potential use of plant taxa by the people living in Central Italy during the Copper‐Middle Bronze Age and expanded the body of evidence reported by previous palynological and palaeoecological studies. The application of a microscopic approach provided information about domesticated crops and/or gathered wild plants and inferred considerations on ancient environments, water sources, and past health and diseases. Moreover, the research supplied data to define the natural resources (e.g., C4‐plant intake) and the social use of the space during that period. Another important aspect was the finding of plant clues referable to woody habitats, characterised by broad‐leaved deciduous taxa and generally indicative of a warm‐temperate climate and grassy vegetation. Other unusual records (e.g., diatoms, brachysclereids) participated in defining the prehistoric ecological framework. Thus, this work provides an overview on the potential of the human dental calculus analysis to delineate some features of the ancient plant ecology and biodiversity.

The aim of this study is to analyse the impact of the armed conflict in Colombia on the environment, and in particular, terrorist attacks on the oil infrastructure and the phenomenon of oil spills in river basins in the department of Norte de Santander. The study covers the last decade, from 2010 to 2019, and is focused on one of the most violent departments in Colombia, through which the country's most important oil pipeline runs, connecting Caño Limón in Arauca and Coveñas in Sucre. Based on governmental and other reports, the papersituates these acts violence within within the wider dynamics ofarmed confllict. A model is also proposed pointing to the urgency of finding new variables and risk probability factors so that this threat to security in Colombia, currently as unpredictable as it is unresolved, may be effectively managed. [ABSTRACT FROM AUTHOR]

To study the contribution of moisture from different straw-treated and irrigated soil layers to the water consumption of winter wheat in dry farming, a 2-year straw treatment and regulated deficit irrigation experiment was implemented. The field experiment was carried out with 0% (S0), 1% (S1), and 2% (S2) straw returning amounts, and 75 mm (V3), 60 mm (V2), and 45 mm (V1) irrigation volumes. This experiment involved nine treatments, used to quantitatively analyze the ratio and variation of soil water use from different soil layers via the direct contrast method (DCM) and the multiple linear mixed model (MLMM). The results show the following: (1) The distribution of precipitation isotope compositions displayed a repeated trend of first decreasing and then increasing during the study period. Regression analysis showed that the local meteoric water line (LMWL): δD = 6.37δ18O − 3.77 (R2 = 0.832). (2) With increasing soil depth, the δ18O value decreased gradually, and the maximum δ18O value of the soil water within each growth period was distributed at 10 cm. (3) Under the same irrigation amount, δ 18O increased with increasing straw return at 0–20 cm and decreased with increasing straw return at 20–80 cm. (4) The comparison results of the DCM and MLMM were consistent. During the jointing and flowering stages, 0–30 cm soil water was the main source of water for winter wheat. The contribution of soil water below 30 cm had a decreasing trend from the jointing stage to the flowering stage. The average contribution rates of the 0–30 cm soil layer during the jointing and flowering stages were 23.07% and 23.15%, respectively. These findings have important implications for studying the soil water cycle in the context of farming. [ABSTRACT FROM AUTHOR]