Impact of sanitation and socio-economy on groundwater fecal pollution and human health towards achieving sustainable development goals across India from ground-observations and satellite-derived nightlight

Childhood undernutrition mediates the relationship between open defecation with anemia among Ethiopian children: a nationally representative cross-sectional study

BACKGROUND

Poor sanitation and/or open defecation are a significant public health problem in Ethiopia, where access to improved sanitation facilities is still limited. There is a growing body of literature about the effect of open defecation on children's linear growth failure. However, very few studies about the effects of open defecation on child anemia exist. In this study, we examine whether childhood undernutrition (i.e. stunting, wasting, and underweight) mediates the relationship between open defecation and childhood anemia in children aged 6-59 months in Ethiopia.

METHODS

We used pooled Ethiopia Demographic and Health Survey data (2005-2016) comprising 21,918 (weighted data) children aged 6-59 months. Anemia was defined as an altitude-adjusted hemoglobin (Hb) level of less than 11 g/deciliter (g/dl) for children under 5 years. Childhood undernutrition was assessed using height-for-age Z-scores (HAZ), weight-for-age Z-scores (WAZ), and weight-for-height Z-scores (WHZ) for stunting, wasting, and underweight respectively. Mediation effects were calculated using the bootstrap and the indirect effect was considered significant when the 95% bootstrap confidence intervals (95% CI) did not contain zero. Moreover, separate multilevel regression analyses were used to explore the statistical association between open defecation and child anemia, after adjusting for potential confounders.

RESULTS

Our analysis revealed that nearly half (49.6%) of children aged 6 to 59 months were anemic, 46.8% were stunted, 9.9% were wasted, and 29.5% were underweight. Additionally, 45.1% of children belonged to households that practiced open defecation (OD). Open defecation was associated with anemia (AOR: 1.28; 95% CI: 1.18-1.39) and it positively predicted anemia with direct effect of β = 0.233, p < 0.001. Childhood undernutrition showed a partial mediating role in the relationship between OD and anemia. Analyzing the indirect effects, results revealed that child undernutrition significantly mediated the relationship between open defecation and anemia (stunting (βindirect = 0.014, p < 0.001), wasting (βindirect = 0.009, p = 0.002), and underweight (βindirect = 0.012, p < 0.001)). When the mediating role of child undernutrition was accounted for, open defecation had a positive impact on anemia with a total effect of βtotal = 0.285, p < 0.001.

CONCLUSION

Open defecation showed a significant direct effect on anemia. Child undernutrition remarkably mediated the relationship between OD and anemia that further magnified the effect. This finding has an important programmatic implication calling for strengthened, accelerated and large-scale implementation of strategies to end open defecation and achieve universal access to sanitation in Ethiopia.

Assessment of groundwater quality for human consumption and its health risks in the Middle Magdalena Valley, Colombia

Groundwater is the primary source of water for people living in rural areas, especially during seasons when surface water is contaminated or unavailable. In Colombia, people use groundwater as drinking water without additional treatment. In addition, there is no infrastructure for wastewater collection and sewage treatment in the region of the Middle Magdalena Valley. The current study aims to evaluate the quality of groundwater in this region to determine any potential health hazards associated with its consumption. To reach the objective, three (3) physicochemical and microbiological sampling campaigns were carried out during different hydrological periods. A total of 428 groundwater samples were analyzed for over 28 parameters. The results were compared with the water quality standards proposed by the US EPA and Colombian regulations for human consumption. The analysis revealed the presence of total and fecal coliforms in 89% and 58% of the analyzed samples, respectively, identifying them as the main contaminants in groundwater. Furthermore, the pH levels did not meet the standards set by the US EPA in 33.8% of the cases and by Colombian regulations in 31.02%. Additionally, 32.8%, 17.6%, 14.3%, and 10.9% of the samples failed to meet the established thresholds for apparent color, magnesium, iron, and nitrates, respectively, under both standards. Moreover, only the analyses of selenium, mercury, and zinc complied with the quality standards under both regulatory frameworks. Based on the Colombian Drinking-Water Quality Risk Index (CDWQRI-IRCA), the risk associated with water quality meant for human consumption was assessed. The results showed that over 84% of the samples analyzed posed a high risk to human health, 4.6% posed a medium risk, 5.5% posed a low risk, and only 5.7% posed no risk at all. Additionally, official mortality statistics for children under four years old were reviewed, which revealed two deaths in 2019 due to Acute Diarrheal Disease (ADD) caused by consumption of contaminated water. Therefore, it is crucial to implement water treatment systems, establish aqueducts in rural areas, and conduct rigorous and systematic monitoring of drinking water to ensure it is safe for human consumption. It is also important to track morbidity and mortality rates associated with water consumption.

Solution of convection-diffusion model in groundwater pollution

This research involves the development of the spectral collocation method based on orthogonalized Bernoulli polynomials to the solution of time-fractional convection-diffusion problems arising from groundwater pollution. The main aim is to develop the operational matrices for the fractional derivative and classical derivatives. The advantage of our approach is to orthogonalize the Bernoulli polynomials for the sake of creating sparse operational matrices in such a way that classical derivatives have one sub-diagonal non-zero entries only, and also creating an operational matrix for fractional derivative have diagonal matrix only. Due to these properties, the cost of computational our approach is very low and the convergence is fast. A discussion on the error analysis for the presented approach is given. Two test problems are considered to illustrate the effectiveness and applicability of our method. The absolute error in the computed solution compares with the existing method in the literature. The comparison shows that our method is more accurate and easily implemented.

Seasonal effects on hydrochemistry, microbial diversity, and human health risks in radon-contaminated groundwater areas

Groundwater is an important human resource. Daejeon in South Korea faces severe water quality issues, including radon, uranium, and fluoride pollution, all of which pose health risks to humans. With climate change, threats to potable water, such as heavy rain and typhoons, have become common. Therefore, examining the seasonal effects on groundwater quality and resultant health risks is important for understanding the mechanisms of different hydroclimatological conditions to enable the implementation of sustainable management plans in radon-contaminated groundwater areas. However, this issue has not yet been studied. To bridge this gap, in this study, major ions and microbial community structures were employed and groundwater quality index (GWQI) were calculated with hazard index based on limits set by the World Health Organization (WHO) to investigate the hydrochemical characterization and to assess pollution levels. The results showed that the rainy season had distinct hydrochemical characteristics with high correlations between radon and fluoride, and most groundwater samples collected after the typhoon had characteristics similar to those collected during the dry season, owing to the flow path. Furthermore, the microbial diversity and hazard quotient (HQ) values of fluoride revealed that pollution worsened during the dry season. All of the calculated effective dose values of radon exceeded the threshold limit set by the WHO, despite the low GWQI. Infants and children were particularly susceptible to radon-contaminated groundwater. The statistical results of self-organizing map (SOM) suggested that radon analysis was sufficient for public health intervention in the rainy season; however, in the dry season, combined analyses of radon, fluoride, and microbial diversity played important roles in health risk assessment. Our study presents a comprehensive understanding of radon-contaminated groundwater characteristics under seasonal effects and can serve as a reference for other similar zones to provide significant insights into the effective management of radon contamination.

A 22-Site Comparison of Land-Use Practices, E-coli and Enterococci Concentrations

Land-use practices can greatly impact water quality. Escherichia (E.) coli and Enterococcus are accepted water quality indicators. However, surprisingly little research has been conducted comparing both organisms' population density relationships to land use practices and water quality. Stream water grab samples were collected monthly (n = 9 months) from 22 stream monitoring sites draining varying land use practice types in a representative mixed-land-use watershed of the northeastern United States. E. coli and enterococci colony forming units (CFU per 100 mL) were estimated (n = 396) and statistically analyzed relative to land use practices, hydroclimate, and pH, using a suite of methods, including correlation analysis, Principal Components Analysis (PCA), and Canonical Correspondence Analysis (CCA). Correlation analyses indicated significant (p < 0.05) relationships between fecal indicator bacteria concentrations, water quality metrics and land use practices but emphasized significant (p < 0.05) negative correlations between pH and instream enterococci concentrations. PCA and CCA results indicated consistent spatial differences between fecal indicator bacteria concentrations, pH, and land use/land cover characteristics. The study showed that pH could be considered an integrated proxy variable for past (legacy) and present land use practice influences. Results also bring to question the comparability of E-coli and enterococci relative to dominant land use practices and variations in pH and provide useful information that will help guide land use practice and water pollutant mitigation decision making.

Increased Incidence of Pyogenic Liver Abscess in a Midwest System With Emphasis on Rural Impact

OBJECTIVE

To assess if hepatic abscess incidence in a Midwest cohort was higher in rural areas compared to metropolitan areas in relation to water infrastructure.

MATERIALS AND METHODS

All cases of hepatic abscesses from Jan 1, 2016 through Dec 31, 2019 at Avera McKennan Hospital in Sioux Falls, South Dakota (SD), were retrospectively collected. Chart review was completed for each case for risk factor analysis. Microbiology cultures and patient demographic data were collected including age, gender, hometown, and ethnicity. Risk factors assessed included a history of abdominal surgery, gallbladder disease, sepsis, diverticulitis, cancer, and diabetes. The incidence of hepatic abscesses was calculated using the Poisson rate test and confidence interval equation. Averages of each risk factor were calculated. Finally, hometown was utilized to create a heatmap of disease burden and compared to the density of private wells.

RESULTS

Our data yielded 116 confirmed adult hepatic abscesses between 2016 and 2019. The corrected incidence per 100,000 hospitalized patients per year is 95.66. The Poisson exact probability P-value was <0.01. Rural areas had a higher per capita incidence of abscesses and higher density of private wells.

CONCLUSIONS

The incidence of hepatic abscesses is higher than national averages in this single-center study of Avera McKennan Hospital. Demographics, especially geographic location, play an important role in abscess rates. Rural location may be affecting the incidence of hepatic abscesses, explaining the much higher than expected incidence in this study. Infrastructure could be a contributing factor as much of the rural area is reliant on untreated groundwater.

Predicting factors of public awareness and perception about the quality, safety of drinking water, and pollution incidents

Public perception of drinking water quality and safety results from the interaction of multiple factors, including the public engagement, which requires sufficient knowledge and awareness. This issue has yet to be addressed in Algeria. This study investigated the residents' perception and awareness about the drinking water quality, safety, and water pollution events. A survey-based cross-sectional study was conducted amongst citizens living in the province of Biskra. Multinomial regression analysis was used to identify the predicted public perception factors about drinking water-related issues. Regardless of the degree of public trust in the drinking water sources, the main drinking water source reported by the participants was tank water (43.3%) followed by tap water (32%). Water quality standards are a measure of the condition of water relative to the contaminants. Water consumption profiles gave priority attention to taste (48.7%), odour (35%), appearance (34.7%), and colour (32%), reflecting a low level of knowledge about the water quality standards. Most of the residents (55.7%) reported a deficient communication about the preventive measures to protect public health. The higher level of education showed a statistically significant impact in discriminating between those who felt very satisfied and dissatisfied participants with the drinking water quality and those who felt between satisfied and dissatisfied (P = 0.023, P = 0.034, respectively). Additionally, education level had a statistically significant role in differentiating trust levels in drinking water quality between two groups, those belonging to either confident or relatively confident and the group of extremely worried respondents, with P = 0.000 and P = 0.000, respectively. Interviewed respondents with certain education levels showed higher trust in the safety of drinking water when compared to those with lower education levels. Gender had a significant role in differentiating the group of respondents who were relatively confident from those who were extremely worried (P = 0.016). The public knowledge about the standards of water quality, safety, and the pollution-related issues remains relatively low. This study is of interest to policy makers and public health authorities who implement actions for water contamination prevention and public health protection. These findings could have national implications and are also applicable, in general context, particularly in low and middle-income countries.

Susceptibility Prediction of Groundwater Hardness Using Ensemble Machine Learning Models

Groundwater resources, unlike surface water, are more vulnerable to disturbances and contaminations, as they take a very long time and significant cost to recover. So, predictive modeling and prevention strategies can empower policymakers for efficient groundwater governance through informed decisions and recommendations. Due to the importance of groundwater quality modeling, the hardness susceptibility mapping using machine learning (ML) models has not been explored. For the first time, the current research aimed to predict groundwater hardness susceptibility using the ML models. The performance of two ensemble models of boosted regression trees (BRT) and random forest (RF) is investigated through the arrangement of a comparative study with multivariate discriminant analysis (MDA). According to the hardness values in 135 groundwater quality monitoring wells, the hard and soft water are determined; then, 11 predictor variables including distance from the sea (DFS), land use, elevation, distance from the river (DFR), depth to groundwater (DTGW), pH, precipitation (PCP), evaporation (E), groundwater level (GWL), curvature, and lithology are used for predicting the groundwater hardness susceptibility map. Results indicated that the variables of DFR, DTGW, elevation, and DFS had a higher contribution to the modeling process. So, the high harness areas are mostly related to low elevations, low DTGW, and proximity to river and sea, which facilitate the percolation conditions for minerals containing calcium or magnesium into groundwater.