Challenges for Safe and Healthy Drinking Water in China

Control mechanism of Escherichia coli invasion by micro-nano bubbles in drinking water distribution system

Sudden biological contamination in Drinking Water Distribution System (DWDS) significantly threatens the safety of drinking water, with E. coli invasions being particularly hazardous to human health. Traditional disinfection methods (i.e., chlorine, ultraviolet and ozone) provide partial microbial reduction. Micro-nano bubbles (MNBs) offer a promising alternative due to easy preparation, environmental friendliness, and generating ·OH in situ. This study explored the control mechanism of MNBs using different gas sources (i.e., nitrogen, air, oxygen, and ozone) on E. coli invasion in drinking water of the secondary water supply tanks. MNB characteristics, water quality changes, bacterial concentration, and microbial communities were evaluated. Results indicated that E. coli gradually became the dominant bacterium by promoting species interaction and influencing the process of microbial community construction, leading to a 6.25% increase in bacterial counts in water. MNBs generated via a dissolved gas release method exhibited particle sizes ranging from 500 to 800 nm and Zeta of -0.6 to -3.1 mV, and the bubble collapse effect generated a large amount of ·OH (0.11-0.40 mmol/L), which reduced bacterial abundance by 66.53% and microbial community richness, as revealed by decreases in the Chao (10.53%) and ACE (3.75%) indexes. The oxidative stress induced by ·OH inhibited protein transcription and energy production, which damaged DNA repair mechanisms. Thus, the relative abundance of Gammaproteobacteria, including E. coli as the dominant strain, decreased by 47.6%, leading to a balanced microbial community. Additionally, MNBs showed a complete reduction of bacteria, such as Caldisericia and Fusobacteria, thereby improving the drinking water safety and biological stability. This study highlights the potential of MNBs to address sudden exogenous biological pollution in DWDS, providing critical theoretical support to ensure the safety of drinking water quality.

Fluoride Exposure from Drinking Water Increases the Risk of Stroke: An Ecological Study in Changwu Town, China

BACKGROUND

Stroke is a major cause of death globally and the leading cause in China. Excessive fluoride exposure has been linked to cardiovascular conditions related to stroke risk factors such as hypertension, atherosclerosis, dyslipidemia, and cardiomyopathy. However, evidence supporting the association between fluoride exposure and stroke risk is limited.

METHODS

We constructed an ecological study in Changwu Town, Heilongjiang Province, China, a typical endemic fluorosis area caused by excessive fluoride exposure from drinking water. We collected demographic data, stroke prevalence, and mortality information from 2017 to 2021. Fluoride exposure data were obtained from the national monitoring project on endemic fluorosis. Water fluoride concentrations were measured using the standardized methods. Trend changes in stroke rates were assessed using annual percentage change (APC). Differences in stroke rates among fluoride exposure groups were analyzed using chi-square tests.

RESULTS

From 2017 to 2021, the all-ages and age-standardized stroke prevalence rates of permanent residents in Changwu Town increased year by year, while the all-ages and age-standardized mortality rates did not change significantly. The prevalence rates of stroke were significantly higher in endemic fluorosis areas compared to non-endemic areas (p < 0.001). Stratifying the population into tertile groups based on the water fluoride cumulative exposure index (WFCEI) revealed statistically significant differences in stroke prevalence rates (p < 0.001), showing a dose-response relationship with the WFCEI. However, the all-ages and age-standardized mortality rates of stroke were not found to be related to fluoride exposure.

CONCLUSIONS

Long-term excessive fluoride exposure from drinking water may increase the risk of stroke prevalence, indicating fluoride overexposure as a potential risk factor for stroke.

A Sb(III)-specific efflux transporter from Ensifer adhaerens E-60

Antimony is pervasive environmental toxic substance, and numerous genes encoding mechanisms to resist, transform and extrude the toxic metalloid antimony have been discovered in various microorganisms. Here we identified a major facilitator superfamily (MFS) transporter, AntB, on the chromosome of the arsenite-oxidizing bacterium Ensifer adhaerens E-60 that confers resistance to Sb(III) and Sb(V). The antB gene is adjacent to gene encoding a LysR family transcriptional regulator termed LysRars, which is an As(III)/Sb(III)-responsive transcriptional repressor that is predicted to control expression of antB. Similar antB and lysRars genes are found in related arsenic-resistant bacteria, especially strains of Ensifer adhaerens, and the lysRars gene adjacent to antB encodes a member of a divergent subgroup of putative LysR-type regulators. Closely related AntB and LysRars orthologs contain three conserved cysteine residues, which are Cys17, Cys99, and Cys350 in AntB and Cys81, Cys289 and Cys294 in LysRars, respectively. Expression of antB is induced by As(III), Sb(III), Sb(V) and Rox(III) (4-hydroxy-3-nitrophenyl arsenite). Heterologous expression of antB in E. coli AW3110 (Δars) conferred resistance to Sb(III) and Sb(V) and reduced the intracellular concentration of Sb(III). The discovery of the Sb(III) efflux transporter AntB enriches our knowledge of the role of the efflux transporter in the antimony biogeochemical cycle.

Defending against environmental threats: Unveiling household adaptation strategies and population heterogeneity

Humanity faces a variety of risks from pollution and environmental degradation. Societal advancement has equipped the public with numerous self-protection measures to mitigate these threats. However, the ways in which individuals deploy and balance self-defence mechanisms within this complex risk landscape and the resulting consequences remain largely unexplored. Drawing on a detailed survey of households' self-defence practices, this study rigorously analyses the heterogeneity and driving factors behind household-level self-defence strategies. Through exploratory latent class modelling, we identified four distinct defence patterns: inaction, water-sensitive, air-sensitive, and multifaceted. These patterns reveal varied defence capabilities among the population. By integrating frameworks from economics and social psychology, significant disparities were found in the driving factors behind these patterns. Practices aimed at combating air pollution are primarily driven by the actual severity of pollution and perceived coping capabilities, whereas measures to enhance water quality are influenced more by perceived threats. This disparity arises from variations in information availability and health awareness. The study also highlights a misalignment between the distribution of defence capabilities and the levels of pollution. Given that income restricts self-defence options, this mismatch indicates that economically disadvantaged groups are disproportionately affected by severe health inequalities.

Health impact assessment of the surface water pollution in China

China suffers from severe surface water pollution. Health impact assessment could provide a novel and quantifiable metric for the health burden attributed to surface water pollution. This study establishes a health impact assessment method for surface water pollution based on classic frameworks, integrating the multi-pollutant city water quality index (CWQI), informative epidemiological findings, and benchmark public health information. A relative risk level assignment approach is proposed based on the CWQI, innovatively addressing the challenge in surface water-human exposure risk assessment. A case study assesses the surface water pollution-related health impact in 336 Chinese cities. The results show (1) between 2015 and 2022, total health impact decreased from 3980.42 thousand disability-adjusted life years (DALYs) (95 % Confidence Interval: 3242.67-4339.29) to 3260.10 thousand DALYs (95 % CI: 2475.88-3641.35), measured by total cancer. (2) The annual average health impacts of oesophageal, stomach, colorectal, gallbladder, and pancreatic cancers added up to 2621.20 thousand DALYs (95 % CI: 2095.58-3091.10), revealing the significant health impact of surface water pollution on digestive cancer. (3) In 2022, health impacts in the Beijing-Tianjin-Hebei and surroundings, the Yangtze River Delta, and the middle reaches of the Yangtze River added up to 1893.06 thousand DALYs (95 % CI: 1471.82-2097.88), showing a regional aggregating trend. (4) Surface water pollution control has been the primary driving factor to health impact improvement, contributing -3.49 % to the health impact change from 2015 to 2022. It is the first city-level health impact map for China's surface water pollution. The methods and findings will support the water management policymaking in China and other countries suffering from water pollution.

Review of carbon dot-hydrogel composite material as a future water-environmental regulator

As water pollution and scarcity pose severe threats to the sustainable progress of human society, it is important to develop a method or materials that can accurately and efficiently detect pollutants and purify aquatic environments or exploit marine resources. The compositing of photoluminescent and hydrophilic carbon dots (CDs) with hydrogels bearing three-dimensional networks to form CD-hydrogel composites to protect aquatic environments is a "win-win" strategy. Herein, the feasibility of the aforementioned method has been demonstrated. This paper reviews the recent progress of CD-hydrogel materials used in aquatic environments. First, the synthesis methods for these composites are discussed, and then, the composites are categorized according to different methods of combining the raw materials. Thereafter, the progress in research on CD-hydrogel materials in the field of water quality detection and purification is reviewed in terms of the application of the mechanisms. Finally, the current challenges and prospects of CD-hydrogel materials are described. These results are expected to provide insights into the development of CD-hydrogel composites for researchers in this field.

Analyzing the correlation between quinolone-resistant Escherichia coli resistance rates and climate factors: A comprehensive analysis across 31 Chinese provinces

BACKGROUND

The increasing problem of bacterial resistance, particularly with quinolone-resistant Escherichia coli (QnR eco) poses a serious global health issue.

METHODS

We collected data on QnR eco resistance rates and detection frequencies from 2014 to 2021 via the China Antimicrobial Resistance Surveillance System, complemented by meteorological and socioeconomic data from the China Statistical Yearbook and the China Meteorological Data Service Centre (CMDC). Comprehensive nonparametric testing and multivariate regression models were used in the analysis.

RESULT

Our analysis revealed significant regional differences in QnR eco resistance and detection rates across China. Along the Hu Huanyong Line, resistance rates varied markedly: 49.35 in the northwest, 54.40 on the line, and 52.30 in the southeast (P = 0.001). Detection rates also showed significant geographical variation, with notable differences between regions (P < 0.001). Climate types influenced these rates, with significant variability observed across different climates (P < 0.001). Our predictive model for resistance rates, integrating climate and healthcare factors, explained 64.1% of the variance (adjusted R-squared = 0.641). For detection rates, the model accounted for 19.2% of the variance, highlighting the impact of environmental and healthcare influences.

CONCLUSION

The study found higher resistance rates in warmer, monsoon climates and areas with more public health facilities, but lower rates in cooler, mountainous, or continental climates with more rainfall. This highlights the strong impact of climate on antibiotic resistance. Meanwhile, the predictive model effectively forecasts these resistance rates using China's diverse climate data. This is crucial for public health strategies and helps policymakers and healthcare practitioners tailor their approaches to antibiotic resistance based on local environmental conditions. These insights emphasize the importance of considering regional climates in managing antibiotic resistance.

Drinking water quality evaluation in supply systems in Wuhan, China: application of entropy weight water quality index and multivariate statistical analysis

In this study, source water, finished water, and tap water were sampled monthly from two large drinking water treatment plants in Wuhan city, China for 12 months where physicochemical and microbiological parameters were measured, and the complex monitoring data was analyzed using single-factor assessment method, entropy weight water quality index (EWQI), and multivariate statistical techniques (i.e., cluster analysis (CA), discriminant analysis, and correlation analysis). The results of the single-factor assessment method showed that the total nitrogen pollution was the main problem in the source water quality, and the finished and tap water met the required quality standards. The EWQI values indicated that the overall quality of the source, finished, and tap water samples was "Excellent." In addition, strengthening monitoring of parameters with high entropy weights, including Pb, Hg, sulfide, Cr in surface water and Hg, aerobic bateria count, and As in drinking water, were suggested, as they were prone to drastic changes. Spatial CA grouped the finished and tap water samples from the same plant into a cluster. Temporal CA grouped 12 sampling times of source water into Cluster 1 (June), Cluster 2 (April-May, and July-November), and Cluster 3 (December-March). Concerning finished and tap water, except the October was regrouped, the result of temporal CA was consistent to that of the source water. Based on similar characteristics of water samples, monitoring sites and frequency can be optimized. Moreover, stepwise discriminant analysis indicated that the spatiotemporal variations in water quality among CA-groups were enough to be explained by four or five parameters, which provided a basis for the selection of monitoring parameters. The results of correlation analysis showed that few pairwise correlations were both significant (P < 0.05) and stable across sampling sites, suggesting that the number of monitoring parameters was difficult to reduce through substitution. In summary, this study illustrates the usefulness of EWQI and the multivariate statistical techniques in the water quality assessment and monitoring strategy optimization.

Hidden risks: Simulated leakage of domestic sewage to secondary water supply systems poses serious microbiological risks

There are continuous reports about the pollution of the secondary water supply systems (SWSSs), among which domestic sewage leakage is the most serious. In this study, a pilot experiment lasting 70 days was conducted to explore the changes in physicochemical water quality and the microbial profiles in SWSSs polluted by different doses of domestic sewage through qPCR and high-throughput sequencing methods. The results showed that when domestic sewage entered the simulated water storage tank, a large amount of organic matter brought by domestic sewage quickly consumed chlorine disinfectants. High pollution levels (pollution index ≥ 1/1000) were accompanied by significant increases in turbidity and ammonia nitrogen concentration (p < 0.05) and by abnormal changes in sensory properties. Although different microbial community structures were found only at high pollution levels, qPCR results showed that the abundance of the bacterial 16S rRNA gene and some pathogenic gene markers in the polluted tank increased with the pollution level, and the specific gene marker of pathogens could be detected even at imperceptible pollution levels. In particular, the high detection frequency and abundance of Escherichia coli and Enterococcus faecails in polluted tank water samples demonstrated that they can be used for early warning. Moreover, it seems that the microorganisms that came with the domestic sewage lost their cultivability soon after entering SWSSs but could recover their activities during stagnation. In addition, the biofilm biomass in the polluted tank with high pollution levels increased faster at the initial stage, while after a longer contact time, it tended to remain at the same level as the control tank. This study emphasized the high microbial risk introduced by sewage water leakage even at imperceptible levels and could provide scientific suggestions for early warning and prevention of pollution to SWSSs.

Horizontal transfer and driving factors of extended-spectrum β-lactamase-producing resistance genes in mice intestine after the ingestion of contaminated water

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) has been identified in various water environments, posing a serious risk to public health. However, whether and how ESBL-producing genes in water-derived E. coli can spread among mammalian gut microbiota via drinking water is largely unclear. To address this problem, horizontal transfer characterization of ESBL-producing genes in mice gut microbiota was determined after the oral ingestion of contaminated water by ESBL-producing E. coli, and then the driving factors were comprehensively examined from multiple different perspectives. The results showed that water-borne ESBL-producing E. coli can colonize in the mice intestine, the ESBL-producing genes can horizontally spread among gut microbiota, and the recipient bacteria include opportunistic pathogens Klebsiella pneumoniae and Salmonella enterica. This horizontal spread may be attributed to the intestinal micro-environment changes caused by the ingestion of contaminated water by ESBL-producing E. coli. These changes, including gut microbiota diversity, increased levels of inflammatory response and reactive oxygen species, cell membrane permeability, and expression levels of conjugative transfer-related genes, are all major driving factors for horizontal transfer of ESBL-producing genes in mice gut microbiota. Our findings highlight the potential for ESBL-producing E. coli to spread resistance genes to mammalian gut microbiota during ingestion of contaminated water.

Can the development of renewable energy in China compensate for the damage caused by environmental pollution to residents' health?

China's rapid economic growth in recent decades has caused a growing problem of environmental pollution, which negatively impacts the physical and mental health of residents. In recent years, renewable energy has emerged as a promising solution to alleviate environmental pollution and improve residents' well-being. However, it is unknown whether renewable energy development can counterbalance the health impacts of environmental pollution. Therefore, we conducted a study using data from the China Family Panel Studies (CFPS) to examine the impact of environmental pollution and renewable energy on the health of 20,694 residents. Our analysis showed that renewable energy development can partially offset the negative health effects of environmental pollution. Specifically, we found that a 1% increase in environmental pollution is linked to an average decrease of 0.0911% in physical health (PHY) and 0.0566% in mental health (MEN), whereas each 1% rise in renewable energy corresponds to an average increase of 0.2585% in PHY and 0.1847% in MEN. These positive effects apply to male and female residents, urban and rural residents, young and middle-aged adults, and people with low, medium, and high levels of education. These findings are significant for decision-makers striving to improve Chinese residents' physical and mental health by considering the specific impact of renewable energy and comprehensive environmental pollution.

Spatiotemporal distribution and probabilistic health risk assessment of arsenic in drinking water and wheat in Northwest China

Drinking water arsenic poisoning has been a health concern, however the importance of dietary arsenic exposure to health also needs to be taken into account. The aim of this study was to conduct a comprehensive health risk assessment of arsenic-contaminated substances in drinking water and wheat-based food intake in the Guanzhong Plain, China. 87 samples of wheat and 150 samples of water were randomly selected from the research region and examined. The level of arsenic in 89.33% of the water samples in the region exceeded the limit for drinking water (10 μg/L), with an average concentration of 29.98 μg/L. The arsenic in 2.13% of the wheat samples exceeded the food limit (0.5 mg/kg) with an average concentration of 0.24 mg/kg. Under the situation of different exposure pathways, two scenarios of deterministic and probabilistic health risk assessments were compared and analyzed. By contrast, the probabilistic health risk assessment can ensure a certain degree of confidence in the assessment results. The findings of this study indicated that the total cancer risk value faced by the population aged 3-79 years, except for those aged 4-6 years, was 1.03E-4-1.21E-3, which exceeded the 10E-6-10E-4 range of thresholds usually used by USEPA as guidance recommendations for determination. And the non-cancer risk experienced by the population aged 6 months to 79 years was higher than the acceptable threshold (1), with children aged 9 months to 1 year having the highest total non-cancer risk of 7.25. The potential health risks of the exposed population were mainly due to the drinking water route, and consumption of arsenic-containing wheat increased both carcinogenic and non-carcinogenic risks. Finally, the sensitivity analysis revealed that the assessment findings were most significantly influenced by exposure time. The amount of intake was the second influencing factor in the health risk assessment from drinking water and dietary intakes of arsenic, and arsenic concentration was the second influencing factor in the health risk assessment due to dermal exposure to arsenic. The findings of this study can aid in understanding the negative health consequences of arsenic pollution to local residents and in adopting focused remediation strategies to alleviate environmental concerns.

Hotspots and Trends of Layered Double Hydroxide-based Adsorbents for Polluted Water Treatment: Insights from Bibliometric Analysis

The use of layered double hydroxides (LDHs) as adsorbent for water treatment has been gaining relevance in recent years. In this context, this work aimed to map, through a bibliometric study, the extent of research that deals with the theme. The scientific database used was the Web of Science, and the chronology of the search consideredthe period from 1997 to 2022. The bibliometix R-package and VOSviewer software were used in this study. The searches retrieved a total of 663 documents, from 69 countries, distributed among all continents, which China (328), India (51) and Japan (40) were the most productive countries. Important journals in the environmental area and with high impact factor, such as Chemical Engineering Journal (44), Applied Clay Science (38), Journal of Hazardous Materials (35) and Chemosphere (27) most published in the area. The network of keywords used by the authors indicates that the publications retrieved deal mainly with aspects related to the efficiency of (LDHs) in the removal of different pollutants, the composition, the synthesis route and the association with other materials and/or techniques. The result of this study constitutes an important tool for directing future research on the subject.

Toxicological characteristics of drinking water in two large-scale municipal water supply systems of a metropolitan city in Central China

Drinking water safety is threatened by numerous toxic organic pollutants difficult to chemically monitor. This study aimed to determine the toxicological profiles of organic extracts (OEs) of water samples from source to tap in two drinking water supply systems in a metropolitan city, Central China, during different hydrological periods. Mortality, DNA damage, growth, and development of Caenorhabditis elegans were evaluated following exposure to OEs. The median lethal doses of OEs of drinking water samples (n = 48) ranged from 266 REF (relative enrichment factor) to > 1563 REF. When tested at a dose of 100 REF, 56.25% (27/48) of OEs induced genotoxicity, 4.17% (2/48) inhibited the growth, and 45.83% (22/48) decreased the offspring number in C. elegans. No clear temporal-spatial variation patterns of the OEs toxicity indicators were observed. The correlations among the toxicity indicators were generally poor. The observed toxicities were not closely related to the level of dissolved organic carbon in drinking water. These findings support using multiple endpoint bioassays, such as C. elegans-based approaches, as complementary tools to conventional chemical analysis for drinking water quality monitoring.

China's environmental solutions

China emits unproportionately high concentrations of CO₂ and, due to rapid population growth and industrialization, suffers from air, water, and soil pollution. However, many of these challenges for sustainable growth are being vigorously addressed, and China aims at a CO₂ emission peak by 2030 and carbon neutrality by 2060 ("dual carbon policy"). In addition, nation-wide programs attempt to achieve reforestation and ecological restoration. By 2025, core elements of a "bioeconomy" and a circular economy are expected to be ready. Many of these programs extend into China's international "belt-and-road" initiative (BRI). In this article, we briefly describe the present achievements of China's environmental solutions and the country's visions for a "digital, eco-friendly civilization." KEY POINTS: • China's steps towards environmental cleaning, eco-protection, and decarbonization. • Steps towards a future bioeconomy.

Impact of "Three Red Lines" Water Policy (2011) on Water Usage Efficiency, Production Technology Heterogeneity, and Determinant of Water Productivity Change in China

This research evaluates the effects of the Three Red Lines policy on water usage efficiency (WUE), production technology heterogeneity, and water productivity change in 31 Chinese provinces between 2006 and 2020. SMB-DEA, Meta-frontier analysis, and Malmquist-Luenberger index (MLI) techniques were employed for estimation. Results revealed that the mean WUE (2006-2020) in all Chinese provinces was 0.52, with an improvement potential of 48%. Shanghai, Beijing, Shaanxi, and Tianjin were the best performers. The WUE scores before (2006-2011) and after (2012-2020) water policy implementation were 0.58 and 0.48, respectively; on average, there was more than a 9% decline in WUE after the implementation of the water policy. The eastern region has the most advanced water utilization technology as its technology gap ratio (TGR) is nearly 1. The average MLI (2006-2020) score was 1.13, suggesting that the MLI has increased by 12.57% over the study period. Further technology change (TC) is the key predictor of MLI growth, whereas efficiency change (EC) diminished from 2006 to 2020. The mean MLI score for 2006-2011 was 1.16, whereas the MLI Score for the period 2012-2020 was 1.10, indicating a modest decline following the implementation of the water policy. All three Chinese regions experienced MLI growth during 2006-2020, with TC the main change factor.

Associations among drinking water quality, dyslipidemia, and cognitive function for older adults in China: evidence from CHARLS

BACKGROUND

The current study aimed to examine the association between drinking water quality and cognitive function and to identify the direct and indirect effects of drinking water quality and dyslipidemia on cognitive function among older adults in China.

METHODS

Primary data for the study were selected from China Health and Retirement Longitudinal Study (CHARLS, 2015) and 4,951 respondents aged 60 and above were included. Data on drinking water quality were selected from the 2015 prefectural water quality data from the Institute of Public and Environment Affairs in China and measured by the Blue City Water Quality Index. Dyslipidemia was measured by self-reported dyslipidemia diagnosis and lipid panel. Three composite measures of cognitive function included mental status, episodic memory, and global cognition. Mixed effects models were conducted to assess the associations between drinking water quality or dyslipidemia and cognitive function. The mediation effects of dyslipidemia were examined by path analyses.

RESULTS

Exposure to high quality drinking water was significantly associated with higher scores in mental status, episodic memory, and global cognition (β = 0.34, p < 0.001 for mental status; β = 0.24, p < 0.05 for episodic memory; β = 0.58, p < 0.01 for global cognition). Respondents who reported dyslipidemia diagnosis had higher scores in the three composite measures of cognitive function (β = 0.39, p < 0.001 for mental status; β = 0.27 p < 0.05 for episodic memory; β = 0.66, p < 0.001 for global cognition). An elevated blood triglycerides was only associated with higher scores in mental status (β = 0.21, p < 0.05). Self-reported dyslipidemia diagnosis was a suppressor, which increased the magnitude of the direct effect of drinking water quality on mental status, episodic memory, and global cognition.

CONCLUSION

Drinking water quality was associated with cognitive function in older Chinese and the relationship was independent of natural or socioeconomic variations in neighborhood environments. Improving drinking water quality could be a potential public health effort to delay the onset of cognitive impairment and prevent the dementia pandemic in older people.

Surveillance of Drinking Water Quality Worldwide: Scoping Review Protocol

Universal access to clean and safe drinking water is essential for life maintenance since exposure to poor quality water is harmful to health. Drinking water quality is part of public health actions and, together with sanitation, a human right essential for life and a sustainable development goal. Moreover, an independent surveillance system conducted by the Ministry of Health or government agencies is needed for the safety of drinking water quality. We propose a scoping review protocol to identify and map worldwide surveillance actions and initiatives of drinking water quality implemented by government agencies or public health services. This scoping review protocol is based on the Joanna Briggs Institute manual and guided by the PRISMA-ScR. Articles, theses, dissertations, and official documents consulted in the following databases will be included: Medline/PubMed, Scopus, LILACS, Web of Science, Embase, Engineering Village, and gray literature. No date limit or language will be determined. The authors will develop a worksheet for data extraction. Quantitative (simple descriptive statistics) and qualitative data (thematic analysis) will be analyzed. The final scoping review will present the main findings, impacts, challenges, limitations, and possible research gaps related to surveillance of drinking water quality on population health.

High efficiency three-dimensional electrochemical treatment of amoxicillin wastewater using Mn-Co/GAC particle electrodes and optimization of operating condition

In this work, Mn-Co/GAC particle electrode was prepared by loading Mn and Co as catalysts on granular activated carbon (GAC) and used in a three-dimensional (3D) electrochemical system for mineralization of amoxicillin wastewater. Observation results by SEM, EDS and XRD confirmed that Mn and Co catalysts were successfully loaded onto GAC. The electrochemical properties were measured using an electrochemical workstation. Mn-Co/GAC had a much higher oxygen evolution potential (1.46V) than GAC (1.1V), which demonstrated that it could effectively reduce the oxygen evolution side reaction. In addition, Mn-Co/GAC had an electrochemically active surface area 1.34 times that of GAC and a much smaller mass transfer resistance than GAC, which could provide favorable conditions for the degradation of pollutants. The investigation of the influences of single operating parameters on total organic carbon (TOC) removal rate and electrical energy consumption (EEC) indicated that current density and treatment time had the greatest effect. In order to maximize TOC removal rate and minimize EEC, optimization of operating parameters was also carried out using response surface method in combination with central composite design. The optimal operating parameters were determined as current density of 5.68 mA/cm², electrolyte concentration of 0.127M, particle electrode dosage of 31.14g and treatment time of 120min. Under this optimum operating condition, TOC removal rate of 85.24% and amoxicillin removal rate of 100% could be achieved with a low EEC of 0.073 kWh/g TOC. In addition, TOC removal rate and EEC were significantly improved compared to the use of bare GAC as particle electrode under the same operating conditions, demonstrating the excellent electrocatalytic ability of the new particle electrode Mn-Co/GAC. A possible mechanism of enhanced amoxicillin and TOC removal was also recommended. In summary, the 3D electrochemical method using Mn-Co/GAC particle electrodes is a suitable choice for amoxicillin wastewater treatment.

Experimental Performance Investigation of an Original Rotating Solar Still Design under Realistic Meteorological Conditions

This research article proposes a novel design of solar still; furthermore, it investigates, experimentally, its thermal and productivity performances, as well as its efficiency, under the realistic meteorological conditions of the city of Gafsa, Tunisia (34.4311° N, 8.7757° E), in terms of ambient temperature and solar irradiance. The novel proposed design presents a cylindrical solar still with a rotating transparent plastic (Plexiglass) cover, wiped continuously on the inner surface. A specific technological configuration of the evaporation and condensation compartments is elaborated. A real prototype is manufactured in order to carry out the performance experimental investigation. A performance comparison is carried out between the cylindrical transparent plastic cover rotating and it being fixed, for two experimentation days presenting slightly different meteorological conditions. The experimental water and plastic cover temperatures, the hourly and the cumulative water production, as well as the hourly efficiency are deeply quantified and interpreted.

Integrating field and satellite monitoring for assessing environmental risk associated with bacteria in recreational waters of a large reservoir

In a large South American Reservoir (750 km², limit between Uruguay and Argentina), we characterized the environmental risk posed by cyanobacteria proxies (abundance, toxin concentration, chlorophyll-a) and Escherichia coli abundances, integrating field (six sites, summers 2011-2015) and satellite (750 km², summers 2011-2017) monitoring. We further assessed how well field cyanobacteria quantitative proxies (abundance, toxin concentration, chlorophyll-a and scum formation) used to build a local risk communication system for recreational (bathing) use of waters named "cyano-traffic-light", ongoing since 2011, reflected its outcome. Cyanobacteria abundance in the field ranged from moderate (>20,000 to <100,000 cells mL^-1) to high-risk (>100,000 cells mL^-1), and its abundance was positively related to toxin (microcystin) concentration. Mean microcystin concentrations was within the low (≤2 μg L^-1, 50% sites) or moderate (>2 < 10 μg L^-1, 50% sites) risk categories. On rare occasions, toxin concentration posed a high-risk for human health. E. coli abundance was within the high-risk category (>126 CFU 100 mL^-1) for human health, mostly in the northern part of the reservoir. Cyanobacteria proxies (abundance and toxins) and E. coli abundance were, however, unrelated. The predictive model showed that, out of the four cyanobacteria proxies used to construct the cyano-traffic-light only cyanobacteria abundance (p < 0.05) explained the outcome of the reports, yet with low explanatory power (41%). The satellite monitoring allowed delimiting the extent and magnitude of the environmental risk posed by cyanobacteria at landscape scale (highest risk in the meander parts of the Argentinean side of the reservoir) and producing risk maps that can be used by water management agencies. Based upon our results we propose including E. coli abundances and satellite derived cyanobacteria abundances in the building of the cyano-traffic-light, among other modifications.

Assessing the drinking water quality in the Inner Mongolia Autonomous Region from 2014 to 2018

The objective of this study was to understand the drinking water quality state in the Inner Mongolia Autonomous Region from 2014 to 2018 and to derive information that will provide a basis for improving the drinking water quality in the region. Monitoring data for drinking water from the Inner Mongolia Autonomous Region for 2014 to 2018 were analyzed and the results were compared with GB 5749-2006, the Standard Test Method for Drinking Water, and GB 5749-2006, the Drinking Water Quality Standards. Data for a total of 30,613 water samples were assessed. Of the data for the microbiological index, sensory trait and general chemical index, and toxicological index, 89, 80, and 69% were qualified, respectively. For the toxicological index, the fluoride and nitrate nitrogen data were the least compliant. The water quality in all the cities was generally very suitable for drinking. However, there were marked differences in the qualified rates of drinking water in different areas and the qualified rates of the data for the three indexes were lower in rural areas than in urban areas. Given the varied issues with the drinking water quality, the relevant departments of League cities should implement appropriate and effective treatment measures to improve the drinking water quality and ensure it is safe for residents.

Characterization of drinking groundwater quality in rural areas of Inner Mongolia and assessment of human health risks

Groundwater is an important natural resource of drinking water in rural areas in Inner Mongolia, China. In this study, 4438 drinking groundwater samples were collected from the rural areas of 81 counties in Inner Mongolia, and were analyzed for 16 parameters, including pH, total hardness (TH), chemical oxygen demand (COD), total dissolved solids (TDS), sulfate (SO42-), chloride (Cl-), fluoride (F-), iron (Fe), manganese (Mn), arsenic (As), cadmium (Cd), hexavalent chromium (Cr), lead (Pb), aluminum (Al), cuprum (Cu), zinc (Zn). The groundwater quality was evaluated with water quality index (WQI) and human health risk assessment (HRA). Monte Carlo simulation were applied for the uncertainty and sensitivity analysis in the health risk assessment. The spatial map was employed based on the inverse distance weighted (IDW) interpolation technique. The results reveal that while the hazard quotient (HQ) suggests that the risk of single element contamination is feeble, the hazard index (HI) indicates a potential health risk for the local population. The observed cumulative carcinogenic risk (CCR) indicates a probable risks of carcinogenic health hazards in the study area. The sensitivity analysis revealed that daily ingestion rate (IR), exposure frequency (EF), and the concentrations of As, Mn, F-, and Cr are the most influential parameters for health hazards. The highly polluted areas are mainly distributed in the central and western regions of Inner Mongolia, including Xianghuangqi, New Barag Zuoqi, and Togtoh. It is observed that the groundwater may cause a potential health risk after long-term ingestion. The results of this study will contribute to groundwater management and protection in Inner Mongolia.

Motivations behind individuals’ energy efficiency investments and daily energy-saving behavior: The case of China

The impact of environmental motivations on the individual’s decisions regarding investments in energy efficiency and the adoption of energy-saving habits are analyzed for a representative sample of Chinese inhabitants from the larger Beijing area, replicating a comparative study on Western Europe. For the considered type of energy efficiency investments and daily energy-saving activities similarities and discrepancies between the two regions are discussed in regard to their sociocultural background as well as governmental regulations. The study provides empirical evidence that for Chinese environmental issues if all only play a tertiary role after monetary and regulatory incentives. The findings could suggest that in China policy programs aimed at raising environmental awareness and forming pro-environmental motivations might not lead to an increase in energy efficiency investments and daily energy-saving activities and the Chinese government’s interests in this regard might be better served by implementing corresponding incentives via regulations. In the long-term. However, social peer pressure might affect a change in the Chinese mentality.

Molecular Evidence of the Inhibitory Potential of Melatonin against NaAsO2-Induced Aging in Male Rats

Arsenic (As) poisoning is widespread due to exposure to pollution. The toxic level of (As) causes oxidative stress-induced aging and tissue damage. Since melatonin (MLT) has anti-oxidant and anti-aging properties, we aimed to evaluate the protective effect of MLT against the toxicity of sodium arsenite (NaAsO₂). Healthy male NMRI mice were divided into eight different groups. The control group received a standard regular diet. Other groups were treated with varying diets, including MLT alone, NaAsO₂, and NaAsO₂ plus MLT. After one month of treatment, biochemical and pathological tests were performed on blood, heart, and lung tissue samples. NaAsO₂ increased the levels of TNF-α, 8-hydroxy-2-deoxy guanosine (8OHdG), malondialdehyde (MDA), reactive oxygen species (ROS), and high mobility group box 1 (HMGB1), increased the expression of TNF receptor type 1-associated death domain (TRADD) mRNA and telomerase reverse transcriptase, and decreased the expression of Klotho (KL) mRNA in both plasma and tissues. In contrast, MLT reduced MDA, ROS, HMGB1, lactate, and TNF-α enhanced the mRNA expression of KL, and suppressed the mRNA expression of the TERT and TRADD genes. Thus, MLT confers potent protection against NaAsO₂- induced tissue injury and oxidative stress.

Drinking-Related Metacognitive Guidance Contributes to Students’ Expression of Healthy Drinking Principles as Part of Biology Teaching

Biology education has adopted the goal of educating future generations about sustainable, healthy habits. The current paper focuses on drinking-related nutritional literacy—the characteristic of health education that refers to aspects of healthy drinking: drinking enough water and fewer sugar-sweetened beverages (SSBs). The study aims to foster school students’ critical thinking about the quality and the quantity of what they drink in everyday life. Facilitating students’ metacognitive awareness was achieved, as they were engaged in a biology learning activity centered on the importance of healthy drinking in everyday life. The study focused on two research questions: 1. What is the contribution of drinking-related metacognitive guidance to the development of metacognitive awareness concerning healthy drinking among students? 2. What is the contribution of drinking-related metacognitive guidance to the way students express the principles and importance of healthy drinking as part of their metacognitive awareness thinking process? The findings indicate a quantitative and qualitative improvement in drinking-related metacognitive awareness among those students who received metacognitive guidance as part of biology teaching. This paper suggests that metacognitive guidance has a significant pedagogical potential to improve sustainable healthy habits among children.