Climate change and its effect on groundwater quality

Impact of climate change and land management on nitrate pollution in the high plains aquifer

High concentrations of nitrate in groundwater pose risks to human and environmental health. This study evaluates the potential impact of climate change, land use, and fertilizer application rates on groundwater nitrate levels in the High Plains Aquifer under four Shared Socioeconomic Pathway (SSP) scenarios. A random forest model, with predictors such as fertilizer application rates, cropland coverage, and climate variables from six Coupled Model Intercomparison Project models, is used to project future nitrate concentrations. Results show increases across all scenarios, with nitrate levels rising by 4% under SSP5-8.5 and up to 13% under SSP2-4.5 when accounting for climate change effects. Fertilizer application rates are identified as the primary driver of projected changes. The northern and central regions of the aquifer exhibited the most pronounced increases. The projected changes in nitrate levels, observed across both low- and high-greenhouse gas emission pathways, highlight the need to develop integrated management strategies that consider shared socioeconomic scenarios and water resource protection constraints.

Assessing groundwater quality and suitability for Agricultural use in Punjab, India: A spatial and temporal analysis

Groundwater is a crucial global water resource; however, it faces the threat of depletion and quality degradation due to intensive agriculture and excessive fertilizer use. In India, groundwater assessments focus mainly on exploitation levels and often neglect quality. This study integrates groundwater quality with exploitation data to evaluate groundwater resources in Punjab, India. A novel Integrated Water Quality Index (IWQI), developed using advanced statistical techniques like Principal Component Analysis (PCA), identified Sodium (Na⁺), Sulphate (SO₄2⁻), Chlorine (Cl⁻), Sodium Adsorption Ratio (SAR), and Electrical Conductivity (EC) as key contributors to groundwater quality. Spatial-temporal maps for 2014 and 2022 classified water quality into five suitability classes: Excellent (0-35), Good (35-60), Poor (60-85), High Restrictions (85-100), and Severe Restrictions (> 100). Hydrogeochemical analyses, including Piper and Durov diagrams, indicated saline water dominance due to high fertilizer use. Notably, water quality degradation was observed in the North-Eastern, Western, and Southern regions, whereas the Central Punjab region, despite over-exploitation, retained excellent water quality for agricultural use. Statistical analysis revealed that 4.7% of the groundwater depth variability was linked to changes in water quality. The block-wise groundwater exploitation map from the Central Groundwater Board was refined to improve resource management and incorporate IWQI data, providing a more comprehensive view of Punjab's groundwater status. This study underscores the importance of integrating water quality into groundwater assessments to inform irrigation strategies and ensure sustainable water resource management.

A preliminary study on the effects of rainfall-related conditions on chromium increase in ultramafic-hosted springs: A possible climate change concern?

This study investigates the impact of intense rainfall on chromium concentrations in five springs discharging from ultramafic rocks in the Northern Apennines (Italy), which are used for drinking water supply through integration into the local water network. Total chromium concentration increased significantly in response to heavy rain, exceeding the WHO drinking water guideline value (up to 80 μg/L) in one spring and the forthcoming 2036 EU target of 25 μg/L in all the springs. This increase could be attributed to a synergistic combination of factors: i) the reduction of Cr(VI) to Cr(III) by natural organic matter (NOM) in soil and transport as NOM-Cr(III) colloids and/or during the oxidation of magnetite to ferrihydrite in the aquifer; ii) the abundance of detrital ultramafic material in the study area, which may store Cr(III)-bearing colloids too; iii) a triggering effect of first intense rainfall after a 20 dry consecutive days period (wet-dry cycle). Moreover, the persistence of a high Cr(III) concentration in the aquifer even a month after the intense rainfall event aligns with previous laboratory studies on NOM-Cr(III) colloidal stability, which showed that such colloids are highly stable and can persist in solution for at least 20 days.

Assessing the long-term trend of spring discharge in a climate change hotspot area

Global warming affects atmospheric and oceanic energy budgets, modifying the Earth's water cycle. The Mediterranean region is a critical zone for climate change due to a decrease in recharge and an increase in the frequency and severity of droughts over recent decades. While the impacts of possible emissions scenarios on surface water have been extensively studied, the effects on groundwater discharge remain uncertain at both global and local scales. The primary objective of this study is to predict the long-term effects of climate change on the discharge of two springs with extensive discharge records, located in distinctly different hydrogeological settings within the Mediterranean climate zone. Through multivariate statistical analyses on secular time-series, correlation factors were identified between the springs' historical discharge and recharge-related parameters representative of their catchment. Future climate projections from a Regional Circulation Model were used to estimate long-term discharge trends of the springs for the 2040-2070 period. The results indicate that the discharge of both springs, on a multi-decadal trend scale, could decrease by 9 % to 11 % by 2040-2070 compared to that of the past few decades. The consistent negative trends observed across the two different hydrogeological settings suggest that the multi-decadal decline in spring discharge is more influenced by climatic factors than by specific hydrogeological features. This leads to the speculation that similar trends could be expected in other springs within Mediterranean-type climates worldwide. Future water shortages will significantly impact the hydrogeological contexts within these climates. Therefore, the long-term outcomes of this study are crucial for assisting water utility agencies in the sustainable management of groundwater resources, providing them with adequate time to plan and implement large-scale infrastructure projects over the coming decades.

The Escalating threat of climate change-driven diseases in fish: Evidence from a global perspective - A literature review

Climate change has brought significant alterations to the aquatic environment, leading to the rapid spread of infectious fish diseases with increasing water temperatures. It is crucial to understand how aquatic pathogens will impact fish in the context of climate change. This study aimed to assess the effects of climate change on fish diseases globally. Data from 104 papers published between 2003 and 2022 were analyzed to identify recent trends in the field. The majority of the studies (54%) focused on parasites, particularly proliferative kidney disease, while 22% examined bacteria. The United States accounted for 19% of the studies, followed by Canada at 14%, covering a wide range of fish species. More research was published on farmed fish (54%) than wild fish (30%), with a higher emphasis on freshwater species (62%) compared to marine species (34%). Most published studies (64%) focused on the local environment rather than the farm level (7%). The findings highlight temperature as a significant threat to global aquaculture and fisheries, impacting the progression of fish diseases. These impacts could be exacerbated by factors such as pH, salinity, and ocean acidification, posing challenges to fish health. Therefore, there is a pressing need for enhanced research and management strategies to address these issues effectively in the future.

Groundwater-rock interactions and mixing in fault-controlled karstic aquifers: A structural, hydrogeochemical and multi-isotopic review of the Pontina Plain (Central Italy)

Karstic aquifers represent crucial water resources and are categorized as either stratigraphically or fault-controlled. This study investigates groundwater-rock interactions and mixing processes within one of the largest fault-controlled karstic aquifers in Central Italy, adjacent to the Pontina plain, which is a highly populated area where agricultural activities and climate change challenge the groundwater assessment of a complex aquifer. We conducted structural, hydrogeochemical, and multi-isotopic screening of ten selected springs with different degrees of mineralization (ranging from Ca-HCO3 to Na-Cl hydrofacies), incorporating new analyses and modeling of δ34S(SO4), δ18O(SO4), 87Sr/86Sr, and δ11B. Additionally, the reinterpretation of a seismic section provides a more detailed framework extending to depths of approximately 5-7 km that allows the identification of the geometry of normal faults, which act as pathways for upwelling fluids. Our findings reveal that hydrogeochemical compositions result from multiple interactions between karstic water and deeper fluids that have interacted with different rocks. Concentration (Na/Li) and isotope (SO4-H2O) geothermometers, coupled with geochemical modeling and trace element analysis, enabled the estimation of a water temperature equilibrium of approximately 95.5 °C, with Triassic evaporites generally corresponding to a depth of approximately 3 km and a temperature of 40 °C with magmatic rocks at approximately 1 km depth, which is likely associated with ongoing tectonics and the Quaternary tectonically controlled Volsci Volcanic Field. To obtain the latter estimate, we used a new geothermometer activity based on the equilibrium between analcime and pollucite. Furthermore, this multidisciplinary approach enhances the understanding of groundwater behavior in fault-controlled karstic aquifers, where mantle-derived CO2 dissolved in groundwater is the driving force behind water-rock interactions. Given the potential for further variations in mixing, which may worsen water quality and increase aquifer vulnerability, periodic monitoring of these processes is essential in a human-impacted environment amidst ongoing climate change.

Characterization of hydrogeochemical elements in determining the ground water quality for irrigation potential and its correlation with climatological parameters of chennai basin aquifer system, southern india

An attempt has been made to comprehend the ground water quality and climate impacts of the Chennai River basin, which is aimed at its main socio-economic growth of the state of Tamil Nadu. The ground water samples collected from the study area were analyzed for its hydrogeochemical elements. The ground water quality and irrigation suitability were determined using several water quality assessment metrics. Ground water is extensively utilized for irrigation in the entire basin area for the past two decades, especially in the 38 over-exploited Firkas out of the 109 Firkas of the basin. It is inferred that the phreatic aquifer ground water quality is fresh in about 20%, as indicated by the EC value (< 750 µs/cm) at 25 °C. In about 63% of the ground water indicating the moderately fresh showing the EC varies between 751 and 2250 µs/cm at 25 °C, 11% of ground water exerted an EC ranging between 2251 and 3000 µs/cm at 25 °C indicating that the ground water is slightly mineralized, and in about 6% of groundwater, the EC is > 3000 µs/cm at 25 °C indicating that the ground water is highly mineralized. There were no water samples that exceeded the permissible limit of chloride either in phreatic aquifer or in fracture aquifer. The changes in rainfall frequency and atmospheric temperature affect the ground water movement and storage directly and indirectly. Similarly, the temperature data shows a positive relationship with the concentration of fluoride and nitrate ions in the water.

Hydro-geochemistry and age-dependent health risk assessment of nitrate, nitrite, and fluoride in health facilities water: a multivariate analysis

Groundwater from alluvial fan plains is the prevailing water source, especially for arid/semiarid regions, but its contamination poses substantial risks to water supply and public health. The recent study aims to assess the hydro-geochemistry, distribution, and potential health risks of NO3-, NO2-, and F- concentrations in the groundwater of previously unexplored health facilities in District Vehari, Punjab, Pakistan. In total, 75 groundwater samples were evaluated for NO3-, NO2-, and F- levels as well as pH, EC, TDS, CO32-, HCO3-, Cl-, Na+, Fe, K+, Ca2+, Mg2+, taste, odor, color, and turbidity. The Durav graph shows that the water type is Na-HCO3-Ca, with Na and HCO3 dominant, weak acids > strong acids, and alkaline ions > alkalis. Results revealed that drinking water samples (21.73% and 20%) taken from Tehsil Mailsi, and the Basic Health Unit (BHU) exceeded the WHO standard (1.5 mg/L) for F- concentration, respectively. Moreover, the mean chronic daily intake (CDI) of F- was 0.044, 0.018, and 0.02 mg/kg/day in children, men, and women, respectively. Similarly, the average CDI of NO3- was 0.113, 0.046, and 0.050 in children, men, and women, respectively, and the respective values of NO2- were 0.004, 0.001, and 0.001. The NO2- shows a significant range of hazard quotient (HQ) (0.0-1.172) in children. The range of HQ for F- was 0.0-3.114, 0.0-1.290, and 0.0-1.389 in children, men, and women, respectively. Additionally, the health risks analysis revealed an HQ > 1.0 for children in groundwater, indicating a potential carcinogenic risk from the F-. Pearson correlation and PCA analysis found a significant positive correlation (0.8) between NO3- and NO2- and a negative correlation (0.3) between F- and HCO3-. These findings highlight the need for groundwater treatment in healthcare facilities prior to water consumption. Enforcing international and national drinking water standards in healthcare units is vital to strengthening services and providing equitable access to safe drinking water. Legislative and efficient water management measures must be taken for the protection of public health.

Harnessing machine learning for assessing climate change influences on groundwater resources: A comprehensive review

Climate change is a major concern for a range of environmental issues including water resources especially groundwater. Recent studies have reported significant impact of various climatic factors such as change in temperature, precipitation, evapotranspiration, etc. on different groundwater variables. For this, a range of tools and techniques are widely used in the literature including advanced machine learning (ML) and artificial intelligence (AI) approaches. To the best of the authors' knowledge, this review is one of the novel studies that offers an in-depth exploration of ML/AI models for evaluating climate change impact on groundwater variables. The study primarily focuses on the efficacy of various ML/AI models in forecasting critical groundwater parameters such as levels, discharge, storage, and quality under various climatic pressures like temperature and precipitation that influence these variables. A total of 65 research papers were selected for review from the year 2017-2023, providing an up-to-date exploration of the advancements in ML/AI methods for assessing the impact of climate change on various groundwater variables. It should be noted that the ML/AI model performance depends on the data attributes like data types, geospatial resolution, temporal scale etc. Moreover, depending on the research aim and objectives of the different studies along with the data availability, various sets of historical/observation data have been used in the reviewed studies Therefore, the reviewed studies considered these attributes for evaluating different ML/AI models. The results of the study highlight the exceptional ability of neural networks, random forest (RF), decision tree (DT), support vector machines (SVM) to perform exceptionally accurate in predicting water resource changes and identifying key determinants of groundwater level fluctuations. Additionally, the review emphasizes on the enhanced accuracy achieved through hybrid and ensemble ML approaches. In terms of Irish context, the study reveals significant climate change risks posing threats to groundwater quantity and quality along with limited research conducted in this avenue. Therefore, the findings of this review can be helpful for understanding the interplay between climate change and groundwater variables along with the details of the various tools and techniques including ML/AI approaches for assessing the impacts of climate changes on groundwater.

The Impact of Exposure to Iodine and Fluorine in Drinking Water on Thyroid Health and Intelligence in School-Age Children: A Cross-Sectional Investigation

Iodine and fluorine, as halogen elements, are often coexisting in water environments, with nearly 200 million people suffering from fluorosis globally, and, in 11 countries and territories, adolescents have iodine intakes higher than that required for the prevention of iodine deficiency disorders. It has been suggested that excess iodine and/or fluorine can affect thyroid health and intellectual development, especially in children, but their combined effect has been less studied in this population. This study investigated 399 school-age children in Tianjin, China, collected drinking water samples from areas where the school-age children lived, and grouped the respondents according to iodine and fluorine levels. Thyroid health was measured using thyroid hormone levels, thyroid volume, and the presence of thyroid nodules; intelligence quotient (IQ) was assessed using the Raven's Progressive Matrices (CRT) test; and monoamine neurotransmitter levels were used to explore the potential relationship between thyroid health and intelligence. Multiple linear regression and restricted cubic spline (RCS) analyses showed that iodine and fluorine were positively correlated with thyroid volume and the incidence of thyroid nodules in school-age children, and negatively correlated with IQ; similar results were obtained in the secondary subgroups based on urinary iodine and urinary fluoride levels. Interaction analyses revealed a synergistic effect of iodine and fluorine. A pathway analysis showed that iodine and fluorine were negatively associated with the secretion of free triiodothyronine (FT3) and free tetraiodothyronine (FT4), which in turn were negatively associated with the secretion of thyroid-stimulating hormone (TSH). Iodine and fluorine may affect IQ in school-aged children through the above pathways that affect thyroid hormone secretion; of these, FT3 and TSH were negatively correlated with IQ, whereas FT4 was positively correlated with IQ. The relationship between thyroid hormones and monoamine neurotransmitters may involve the hypothalamic-pituitary-thyroid axis, with FT4 hormone concentrations positively correlating with dopamine (DA), norepinephrine (NE), and 5-hydroxytryptophan (5-HT) concentrations, and FT3 hormone concentrations positively correlating with DA concentrations. Monoamine neurotransmitters may play a mediating role in the effects of iodine and fluoride on intelligence in schoolchildren. However, this study has some limitations, as the data were derived from a cross-sectional study in Tianjin, China, and no attention was paid to the reciprocal effects of iodine and fluorine at different doses on thyroid health and intelligence in schoolchildren in other regions.

Effects of atrazine on movement, metabolism and gene expression in Pelophylax nigromaculatus larvae under global warming

Global warming and environmental pollutants both pose a threat to the behavior and physiology of animals, but research on the combined effects of the two is limited. Atrazine, a widely used herbicide, has toxic effects on organisms. In this study, the effects of environmental concentrations of atrazine exposure (100 μg/L) for seven days on the movement, metabolism and gene expression related to motility of Pelophylax nigromaculatus larvae (GS8) were investigated under global warming. The results showed that compared to the optimal growth temperature (18 °C), atrazine treatment under global warming (21 °C) significantly increased the average speed (about 11.2 times) and maximum acceleration (about 1.98 times) of P. nigromaculatus larvae, altered the relative abundance of 539 metabolites, including Formyl-5-hydroxykynurenamine, 2,4-Dihydroxybenzophenone, and FAPy-adenine, and changed the nucleotide metabolism, pyrimidine metabolism, glycerophospholipid metabolism, and purine metabolism, as well as increased the gene expression of SPLA2 (about 6.46 times) and CHK (about 3.25 times). In summary, atrazine treatment under global warming caused metabolic disorders in amphibian larvae and increased the expression of some movement-related genes in the brain, resulting in abnormally active.

Space-temporal analysis of groundwater quality in three areas of the state of Yucatán, México, and its relationship with existing anthropogenic activity

Groundwater in the Yucatan State is the only source of water. The karst aquifer in Yucatan is vulnerable to pollution. Anthropic activities in Yucatan, such as pig farming, are usually related to high wastewater discharges and water pollution. Administrative and logistical issues in developing on-site sampling to evaluate water quality are common in Mexico. The RENAMECA database provides official data related to groundwater quality. However, no analysis based on this database has been reported. A groundwater quality evaluation based on five reference pig farms and the effect of spatial and temporal anthropic activities in the study area was developed. Eighteen wells based on their location concerning the selected pig farms were studied. On-site sampling and laboratory analysis of the supply water and wastewater in the study case farm were done. Fecal coliforms (FC) values (maximum 2850 MPN [100 mL] -1) in most cases for supply water wells exceeded the allowed limit by NOM-127-SAA1-2021. The year of monitoring was significant (P <  0.05) on FC concentrations. Population density and the proximity of wells to population centers affect negatively the presence of total dissolved solids (TDS) and total nitrogen (TN). TDS (maximum value 2620 mg L -1) and phosphorus presence could be related to agricultural activities, human settlements, and local aquifer conditions. A local wastewater treatment issue is evident. Groundwater is not quality for consumption without treatment. Regarding the issues in on-site water monitoring, database analysis provides an approximation of the real situation of groundwater quality.

A machine learning approach for predicting and localizing the failure and damage point in sewer networks due to pipe properties

As a basic infrastructure, sewers play an important role in the innards of every city and town to remove unsanitary water from all kinds of livable and functional spaces. Sewer pipe failures (SPFs) are unwanted and unsafe in many ways, as the disturbance that they cause is undeniable. Sewer pipes meet manholes frequently, unlike water distribution systems, as in sewers, water movement is due to gravity and manholes are needed in every intersection as well as through pipe length. Many studies have been focused on sewer pipe failures and so on, but few investigations have been done to show the effect of manhole proximity on pipe failure. Predicting and localizing the sewer pipe failures is affected by different parameters of sewer pipe properties, such as material, age, slope, and depth of the sewer pipes. This study investigates the applicability of a support vector machine (SVM), a supervised machine learning (ML) algorithm, for the development of a prediction model to predict sewer pipe failures and the effects of manhole proximity. The results show that SVM with an accuracy of 84% can properly approximate the manhole effects on sewer pipe failures.

Spatio-temporal variability of public water supply characteristics and associated health hazards for children and adults in selected locations of Ambala, India

The contamination of public water supply and groundwater resources is a major concern in many parts of developing nations. Polluted water poses serious health risks to humans and the environment. This research was conducted to investigate the seasonal variations of the water quality parameters in the public water supply. To assess the supply water quality in different blocks of Ambala District, hydro-chemical analysis was conducted after a series of systematic sampling in various locations. The statistical tools for water quality indexing including water quality indexing (WQI), heavy metal pollution indexing (HMPI), pollution indexing (PI), overall pollution indexing (OPI), metal indexing (MI), and hazard indexing (HI) were used for data as well as the health hazard analysis through water pathway. Overall, 40 water samples were taken from the public water supply systems covering winter and summer seasons, and the levels of pH, total dissolved solids (TDS), EC, F- , Cl- , NO3 - , SO4 2- , HCO3 - , As, B, Cd, Co, Pb, Zn, Cr, Fe, and Mn were investigated. The weight arithmetic index method was used for WQI, and water pollution indices such as HMPI, PI, OPI, and MI were calculated using different models to check the severity of contamination. The mean hazard quotient and hazard index values calculated using the concentration levels of As, B, Cd, Co, Pb, Cr, Fe, Mn, Zn, F- , and NO3 - reveal that supply water may pose a significant health risk to both adults and children that further varies with temporal and spatial changes. During both seasons, a high carcinogenic risk for both adults and children was observed in the studied area because of high levels of As, Pb, Cd, and NO3 - . PRACTITIONER POINTS: The quality of public supply water was assessed at the selected sites of Ambala, India. High levels of NO3 - , As, Cd, and Pb were observed posing a health risk to adults and children via water pathway. 95% of the samples qualified for the excellent water quality category with respect to the levels of F- , Cl- , NO3 - , SO4 2- , HCO3 - , pH, EC, and TDS. Statistical analysis (HMPI, PI, MI, OPI, HI) using different models revealed water contamination with reference to the levels of NO3 - , As, Pb, Cr, Ni, and Cd. Immediate measures are needed to uphold the safety and health of the natives.

Monthly variations of groundwater arsenic risk under future climate scenarios in 2081-2100

The seasonal variations of shallow groundwater arsenic have been widely documented. To gain insight into the monthly variations and mechanisms behind high groundwater arsenic and arsenic exposure risk in different climate scenarios, the monthly probability of high groundwater arsenic in Hetao Basin was simulated through random forest model. The model was based on arsenic concentrations obtained from 566 groundwater sample sites, and the variables considered included soil properties, climate, topography, and landform parameters. The results revealed that spatial patterns of high groundwater arsenic showed some fluctuations among months under different future climate scenarios. The probability of high total arsenic and trivalent arsenic was found to be elevated at the start of the rainy season, only to rapidly decrease with increasing precipitation and temperature. The probability then increased again after the rainy season. The areas with an increased probability of high total arsenic and trivalent arsenic and arsenic exposure risk under SSP126 were typically found in the high-arsenic areas of 2019, while those with decreased probabilities were observed in low-arsenic areas. Under SSP585, which involves a significant increase in precipitation and temperature, the probability of high total arsenic and trivalent arsenic and arsenic exposure risk was widely reduced. However, the probability of high total arsenic and trivalent arsenic and arsenic exposure risk was mainly observed in low-arsenic areas from SSP126 to SSP585. In conclusion, the consumption of groundwater for human and livestock drinking remains a threat to human health due to high arsenic exposure under future climate scenarios.

Distribution, sources, and potential health risks of fluoride, total iodine, and nitrate in rural drinking water sources of North and East China

Small-scale water sources serving villages and towns are the main source of drinking water in rural areas. Compared to centralized water sources, rural water sources are less frequently monitored for water quality and have poor post-treatment facilities, making them vulnerable to drinking health risks. To reveal the hydrochemical characteristics, contaminant sources, and health risks in rural water sources, 189 water samples were collected from lakes and reservoirs, rivers, and groundwater in North and East China for major ions, nutrient salts, microelements, and stable isotope analysis. Statistical analysis and isotopic tracing were performed, as well as human health risk assessment. The exceeding threshold rates for fluoride (F-) and nitrate (NO3-) in surface water were 1.8 % and 9.1 %, respectively. For groundwater, the exceeding threshold rates were 20.9 % for F-, 15.7 % for total iodine (TI), and 4.5 % for NO3-. F- and TI were mainly derived from the leaching of fluoride- and iodine-containing minerals by cationic exchange, and NO3- is mainly derived from nitrogen in the soil (31.7-43.9 %), the use of ammonia fertilizers (24.3-36.1 %), and the discharge of manure and sewage (19.4-31.9 %). Nitrogen in the soil can be an important source of nitrate in the aquatic environment, and soils with higher clay content have a greater retention effect on the migration of nitrogen pollutants from the surface to the groundwater. F- in water sources contributes most to human health risks for drinking, followed by NO3- and TI, and a higher proportion of groundwater (37 %) present health risks for drinking than surface water (14 %) for children. Authorities should give high priority to optimizing the choice of water sources and technology for water treatment, and rational measures should be taken to protect water sources from the threats of anthropogenic pollution.

Environmental health knowledge of healthcare professionals: Instrument development and validation using the Rasch model

INTRODUCTION

environmental risk factors constitute a major public health issue, calling for preventive actions and interventions at multiple levels. An important step in this direction is increasing the environmental health (EH) knowledge of the healthcare professionals. In this context, tools designed to measure such knowledge are of imperative importance. The aim of the present study was to develop an EH knowledge tool for healthcare professionals.

METHODS

a group of experts defined the knowledge areas of the EH tool and their corresponding items. An online pilot and a validation study were performed. Internal consistency reliability was measured with the Kuder-Richardson 20 (KR-20) estimate, the construct validity and uni-dimensionality of the tool were assessed with the Rasch model. Known-groups validity was analysed with the two-sample t-test.

RESULTS

a total of n = 151 and n = 444 healthcare professionals and end-year medical and nursing students, participated in the pilot and the validation study, respectively. The resulting 33-item EH knowledge questionnaire for healthcare professionals (EHKQ-HP) obtained a KR-20 = 0.82. The scale is uni-dimensional. Its construct validity was verified, and its items cover a wide range of difficulties. Separation statistics were adequate and known-groups behaved as hypothesized.

CONCLUSIONS

the EHKQ-HP is a valuable resource for measuring the EH knowledge of the healthcare professionals. As such it will be useful in detecting EH knowledge gaps, and helping public health agents in making informed decisions when developing interventions for increasing this very knowledge. This would consequently help in improving the health of the general population.

Hotspot and accumulated hotspot analysis for assessment of groundwater quality and pollution indices using GIS in the arid region of Iran

Because groundwater quality representatives for drinking usage (i.e., Schuler method, Nitrate and Groundwater Quality Index) have been abruptly changing due to extreme events induced by global climate change and over-abstracting, applying an efficient tool for their assessments is vitally important. While hotspot analysis is introduced as an efficient tool concentrating on sharp changes in groundwater quality, it has not been closely examined. Accordingly, this study is an attempt to determine the groundwater quality proxies and assess them through hotspot and accumulated hotspot analyses. To this end, a GIS-based hotspot analysis (HA) applying Getis-Ord Gi* statistics was used. The accumulated hotspot analysis was launched to identify the Groundwater Quality Index (AHA-GQI). Moreover, Schuler method (AHA-SM) was utilized to determine the maximum levels (ML) for the hottest hotspot and the lowest levels (LL) for the coldest cold-spot, and compound levels (CL). The results revealed that a significant correlation (r = 0.8) between GQI and SM was observed. However, the correlation between GQI and nitrate was not significant and the correlation between SM and nitrate was so low (r = 0.298, sig > 0.05). The results also demonstrated that using hotspot analysis on only GQI, the correlation between GQI and SM increased from 0.8 to 0.856, while using hotspot analysis on both GQI and SM increased the correlation to 0.945. Likewise, when GQI was subjected to hotspot analysis and SM underwent accumulated hotspot analysis (i.e., AHA-SM (ML)), the correlation degree increased to the highest extent (i.e., 0.958), indicating the usefulness of including the hotspot analysis and accumulated hotspot analysis in the evaluation of groundwater quality.

Hydrogeochemical assessment and health-related risks due to toxic element ingestion and dermal contact within the Nnewi-Awka urban areas, Nigeria

Awka and Nnewi metropolises are known for intensive socioeconomic activities that could predispose the available groundwater to pollution. In this paper, an integrated investigation of the drinking water quality and associated human health risks of contaminated groundwater was carried out using geochemical models, numerical water quality models, and the HHRISK code. Physicochemical analysis revealed that the groundwater pH is acidic. Predicted results from PHREEQC model showed that most of the major chemical and trace elements occurred as free mobile ions while a few were bounded to their various hydrated, oxides and carbonate phases. This may have limited their concentration in the groundwater; implying that apart from anthropogenic influx, the metals and their species also occur in the groundwater as a result of geogenic processes. The PHREEQC-based insights were also supported by joint multivariate statistical analyses. Groundwater quality index, pollution index of groundwater, heavy metal toxicity load, and heavy metal evaluation index revealed that 60-70% of the groundwater samples within the two metropolises are unsuitable for drinking as a result of anthropogenic influx, with Pb and Cd identified as the priority elements influencing the water quality. The HHRISK code evaluated the ingestion and dermal exposure pathway of the consumption of contaminated water for children and adult. Results revealed that groundwater from both areas poses a very high chronic and carcinogenic risk from ingestion than dermal contact with the children population showing greater vulnerability. Aggregated and cumulative HHRISK coefficients identified Cd, Pb, and Cu, to have the highest health impact on the groundwater quality of both areas; with residents around Awka appearing to be at greater risks. There is, therefore, an urgent need for the adoption of a state-of-the-art waste management and water treatment strategies to ensure safe drinking water for the public.

New application to remediate drinkable groundwater from excess of hardness ions by using sodalite bearing modified illite

Calcium Hardness (Ca. H) and total Hardness ions in drinkable groundwater cause great problems for the entire world especially, the population communities which are located far from surface water sources. The present study investigates the use of Sodalite Bearing Modified Illite (SBMI) as a sustainable and new technique to eliminate these ions from drinkable groundwater to compatible with the instruction of the World Health Organization. The methodology was achieved by using a new method to remove these ions' excess calcium Hardness and total Hardness depending on two main processes; the adsorption as a first step and the coagulation-flocculation-sedimentation process as a second step. The results of this study were achieved through conducting three tasks; (1) Chemical analysis surveys for all the groundwater wells, to determine the areas which are more affected by these salts, and plot them on the location maps. (2) Conducting the alkaline modification of the Illite ore to obtain the (SBMI) which has a high surface area and high adsorption ability, and it had been characterized by using XRD, XRF, SEM, and FTIR techniques. (3) The experimental studies were conducted to evaluate the effect of the modified Illite on raw groundwater containing a high concentration of hardness ions, through the batch studies to determine the factors which affected its ability for removing these ions from groundwater. The present study illustrated that the removing efficiency for both total hardness (Ca. H + Mg. H) and calcium hardness (Ca. H) reached about 98%. Finally, the present study recommended using this technique, when there is a requirement for large quantities of treated water at a low cost.

Investigation of temporal variation of groundwater salinity potential using AHP-based index

In this study, a Groundwater Salinity Index (GSI) was developed to monitor the salinity potential and water quality of freshwater aquifers adjacent to Lake Tuz, one of the world's hypersaline lakes. The hierarchical structure of the index was designed by using the Analytical Hierarchy Process and eight different parameters that cause groundwater salinity. In addition to the index, a classification system based on GSI scores is proposed that evaluates salinity potential in three different categories as "high," "medium," and "low." In order to evaluate the temporal variation of salinity potential, the GSI was applied to the results of the water chemistry analysis carried out in 2012 and 2019. Prediction maps showing the salinity potential were obtained using GSI scores and the Kriging interpolation process. According to the index scores and maps, it was determined that the salinity potential rose towards the inner parts of the region because of the increasing salinity rate of groundwater as approximately 15%. The fields with the highest salinity potential are concentrated in the western regions along the shore of Lake Tuz. The groundwater closer to the lake has the characteristics of NaCl facies. Due to the mixing of NaCl and CaHCO₃ water facies at various rates, different water types have emerged in the region. Freshwater aquifers located close to Lake Tuz were mainly contaminated by Lake Tuz and the groundwater that has a high salt content as a result of water-rock interaction.

Research on the Optimal Regulation of Sudden Water Pollution

For the needs of the whole region's emergency regulation of the nullah sudden water pollution event, the emergency regulation strategy of the accident section and upstream and downstream of the sudden water pollution event is studied. For the accident section, the duration of the whole emergency event is calculated using the parameter quantification method; for the upstream of the accident section, the NSGA-II is used to adjust the gate opening to ensure the water level stability of the upstream pools; for the downstream section, the optimized partition method is used to identify the unfavorable pools and close the unfavorable pool to extend the water supply time. Based on the example of an emergency event in the section of the Liyanghe gate-Guyunhe gate of the middle line project, the research results are as follows: the accident section is identified as the Xiaohe gate-Hutuohe gate, the upstream of the accident section is the Liyanghe gate-Xiaohe gate, and the downstream of the accident section is the Hutuohe gate-Gangtou Tunnel gate. The duration of the emergency event in the accident section is 7.9 h; the maximum average water level deviation before the gate upstream of the accident section is 0.05 m; two unfavorable canal pools are identified in the stream of the accident section, and the water supply time of the unfavorable pools is extended by 6.13 and 5.61 d.

Floristic composition and community analysis of woody species in Hereje Natural Forest, southwest Ethiopia

The floristic composition, diversity, and conservation status of woody plant species in Ethiopia are determined in this study. Data on vegetation are collected using a systematic random sampling method from 45 20 m × 20 m  (400m2) plots laid every 100 m along four parallel transect lines running from south to north. The Flora of Ethiopia and Eritrea identification key (Volume I–VIII) is used to identify the scientific names of all woody plant species. The Shannon–Wiener diversity index is used to calculate species diversity, whereas Sorensen's similarity coefficient is used to assess similarities and differences among plant communities. The studied forest contains 44 plant species from 29 families and 40 genera. The Fabaceae is the most dominant family, followed by the Rubiaceae and Combretaceae. In terms of habit, the collected woody species consisted of 30 (68.2%) trees and 14 (31.8%) shrubs. The two most frequent species are Syzygium guineense (51.11%) and Maytenus gracilipes (46.66%). Three plant community types are identified using Agglomerative Hierarchical Cluster Analysis. Most species (Calpurnia aurea-Combretum molle) are observed in community type two. The study is generally limited to the floristic and diversity of woody plant species. Therefore, a thorough investigation of all species' floristic composition, population structure, regeneration status, and ecological aspects is recommended.

Predicting Potential Climate Change Impacts on Groundwater Nitrate Pollution and Risk in an Intensely Cultivated Area of South Asia

One of the potential impacts of climate change is enhanced groundwater contamination by geogenic and anthropogenic contaminants. Such impacts should be most evident in areas with high land-use change footprint. Here, we provide a novel documentation of the impact on groundwater nitrate (GWNO3 ) pollution with and without climate change in one of the most intensely groundwater-irrigated areas of South Asia (northwest India) as a consequence of changes in land use and agricultural practices at present and predicted future times. We assessed the probabilistic risk of GWNO3 pollution considering climate changes under two representative concentration pathways (RCPs), i.e., RCP 4.5 and 8.5 for 2030 and 2040, using a machine learning (Random Forest) framework. We also evaluated variations in GWNO3 distribution against a no climate change (NCC) scenario considering 2020 status quo climate conditions. The climate change projections showed that the annual temperatures would rise under both RCPs. The precipitation is predicted to rise by 5% under RCP 8.5 by 2040, while it would decline under RCP 4.5. The predicted scenarios indicate that the areas at high risk of GWNO3 pollution will increase to 49 and 50% in 2030 and 66 and 65% in 2040 under RCP 4.5 and 8.5, respectively. These predictions are higher compared to the NCC condition (43% in 2030 and 60% in 2040). However, the areas at high risk can decrease significantly by 2040 with restricted fertilizer usage, especially under the RCP 8.5 scenario. The risk maps identified the central, south, and southeastern parts of the study area to be at persistent high risk of GWNO3 pollution. The outcomes show that the climate factors may impose a significant influence on the GWNO3 pollution, and if fertilizer inputs and land uses are not managed properly, future climate change scenarios can critically impact the groundwater quality in highly agrarian areas.

Hydrochemistry of Medium-Size Pristine Rivers in Boreal and Subarctic Zone: Disentangling Effect of Landscape Parameters across a Permafrost, Climate, and Vegetation Gradient

We studied two medium size pristine rivers (Taz and Ket) of boreal and subarctic zone, western Siberia, for a better understanding of the environmental factors controlling major and trace element transport in riverine systems. Our main objective was to test the impact of climate and land cover parameters (permafrost, vegetation, water coverage, soil organic carbon, and lithology) on carbon, major and trace element concentration in the main stem and tributaries of each river separately and when considering them together, across contrasting climate/permafrost zones. In the permafrost-bearing Taz River (main stem and 17 tributaries), sizable control of vegetation on element concentration was revealed. In particular, light coniferous and broadleaf mixed forest controlled DOC, and some nutrients (NO2, NO3, Mn, Fe, Mo, Cd, Ba), deciduous needle-leaf forest positively correlated with macronutrients (PO4, Ptot, Si, Mg, P, Ca) and Sr, and dark needle-leaf forest impacted Ntot, Al, and Rb. Organic C stock in the upper 30–100 cm soil positively correlated with Be, Mn, Co, Mo, Cd, Sb, and Bi. In the Ket River basin (large right tributary of the Ob River) and its 26 tributaries, we revealed a correlation between the phytomass stock at the watershed and alkaline-earth metals and U concentration in the river water. This control was weakly pronounced during high-water period (spring flood) and mostly occurred during summer low water period. Pairwise correlations between elements in both river systems demonstrated two group of solutes—(1) positively correlated with DIC (Si, alkalis (Li, Na), alkaline-earth metals (Mg, Ca, Sr, Ba), and U), this link originated from groundwater feeding of the river when the labile elements were leached from soluble minerals such as carbonates; and (2) elements positively correlated with DOC (trivalent, tetravalent, and other hydrolysates, Se and Cs). This group reflected mobilization from upper silicate mineral soil profile and plant litter, which was strongly facilitated by element colloidal status, notably for low-mobile geochemical tracers. The observed DOC vs DIC control on riverine transport of low-soluble and highly mobile elements, respectively, is also consistent with former observations in both river and lake waters of the WSL as well as in soil waters and permafrost ice. A principal component analysis demonstrated three main factors potentially controlling the major and TE concentrations. The first factor, responsible for 26% of overall variation, included aluminum and other low mobile trivalent and tetravalent hydrolysates, Be, Cr, Nb, and elements strongly complexed with DOM such as Cu and Se. This factor presumably reflected the presence of organo-mineral colloids, and it was positively affected by the proportion of forest and organic C in soils of the watershed. The second factor (14% variation) likely represented a combined effect of productive litter in larch forest growing on carbonate-rich rocks and groundwater feeding of the rivers and acted on labile Na, Mg, Si, Ca, P, and Fe(II), but also DOC, micronutrients (Zn, Rb, Ba), and phytomass at the watershed. Via applying a substituting space for time approach for south-north gradient of studied river basins, we predict that climate warming in northern rivers may double or triple the concentration of DIC, Ca, Sr, U, but also increase the concentration of DOC, POC, and nutrients.

Managing groundwater resources using a national reference database: the French ADES concept

Abstract

Groundwater is an integral part of the water cycle and an essential human resource. Humans must protect this ever-changing heritage and preserve it in a sustainable way by understanding the physical and chemical properties of aquifers and monitoring their quantity and quality. Numerous studies have collected immense volumes of data that are difficult to access and not always comparable or of adequate quality. A pioneering national-scale database, ADES, was created in 1999 to store and make available quality data on French groundwater. This tool is freely accessible for/to water managers, scientists and the public. The data management system used in the database satisfies two important objectives: it is interoperable and based on a recognised groundwater reference system and provides high quality data to a large public. Data from different producers require normalisation and standardisation of system requirements to allow data integration and exchange. The database designers set up shared data models, and based the system on communal repositories of water points and hydrogeological entities. Nearly 102 million groundwater quality records and over 17 million water-level records are currently available, describing almost 61,800 stations. ADES makes it possible to visualise in “real-time" water level data for approximately 1500 stations equipped with GPRS (General Packet Radio Service) technology. ADES also provides, on a public website and via web services, public quantitative and qualitative data. ADES is an essential tool for developing groundwater services based on the FAIR guiding principles: Findable, Accessible, Interoperable and Reusable data (Wilkinson et al. in SD 3:160018, 2016)

Article highlights

The Evaluation of Temporal and Spatial Trends of Global Warming and Extreme Ocean Surface Temperatures: A Case Study of Canada

In recent years, extreme weather has frequently occurred worldwide and caused significant disasters, including large-scale forest fires, rare heat waves, heavy rains, floods, and tornadoes. Those have caused unprecedented losses of human lives and property in some countries, affecting the livelihoods of many people. Climate change and natural disasters are the two hotspots of scientific research today, and there is a certain degree of correlation between the two. Although countries worldwide have long known about climate change and its threats to human existence and have been discussing countermeasures, they have still not been able to carry out concerted and practical actions. The study takes Canada as an example, and selects six representative provinces to evaluate the temporal change characteristics of extreme temperature at different sites. We use MATLAB software to perform multiple linear regression, linear fitting methods, and Pearson correlation analysis to analyze spatial changes and time-space trends. The method studies the relationship between the emergence of extreme weather and climate change and uses the evolutionary game theory to explore whether there is any contradiction between global warming and extreme local cold. The study found: (i) The maximum temperature of most provinces in Canada will be constantly higher, and the minimum temperature will be lower. Generally speaking, the average temperature of each year is slowly decreasing. (ii) The average temperature data of British Columbia (Eastern Pacific) and Quebec (West Atlantic) show that ocean temperature has a specific effect on land temperature in surrounding areas. (iii) Pearson correlation analysis shows that the emergence of extreme weather is closely related to climate change. (iv) The evolution path of the two-party game shows that global warming and the occurrence of extreme local cold are not contradictory. Under the conditions, there is a certain degree of synchronization between the two, interacting and influencing each other.