Water Hyacinth's Extent and Its Implication on Water Quality in Lake Victoria, Uganda.

Water hyacinth (Eichhornia crassipes) degrades and obstructs the integrity of freshwater ecosystems. However, little attention has been paid to monitoring water hyacinth's spatial extent, its determinants, and its effects on water quality in Lake Victoria, Uganda. The specific objectives of this paper are to (i) assess the spatial extent and distribution of water hyacinth; (ii) examine the determinants of water hyacinth distribution, and (iii) assess its impact on water quality. High-resolution satellite images (2016-2019) were obtained and used to monitor the spatial extent of the water hyacinth, a household survey was conducted to examine the determinants of the water hyacinth's extent and patterns while water samples were drawn and analysed for physicochemical properties. Results show that the coverage and distribution of water hyacinth varied over space and time. Water hyacinth coverage primarily increased with a decrease in water surface area. The perceived factors that triggered the water hyacinth spread included the morphology of the Bay, effluent discharge, strong winds, speed of water current, water-level changes, ferry navigation, and construction activities at the shore. Water parameters significantly impacted by hyacinth were pH, TP, BOD, COD, DO, turbidity, and transparency. This study recommends the strict development and implementation of integrated weed control measures, catchment management plans, and point and nonpoint pollution source control.

Caracterización de las aguas residuales generadas en la producción de conjugados monovalentes en el Instituto Finlay de Vacunas / Characterization of the wasteswater generated in the production of conjugated monovalent at the Finlay Vaccine Institute

En la actualidad la contaminación de las aguas terrestres es un grave problema ambiental. La industria farmacéutica es una de las que produce un mayor impacto por la gran variedad de químicos que aporta al agua; sus efluentes generalmente tienen asociadas elevadas cargas orgánicas no biodegradables. La preservación de la calidad de las aguas terrestres es un tema regulado por la legislación nacional, donde se exige la caracterización de las aguas residuales antes de su vertimiento con vistas a evaluar el impacto ambiental que producen y diseñar el sistema adecuado para su tratamiento. El Instituto Finlay de Vacunas, pertenece al grupo de BioCubaFarma, es una empresa de ciclo completo, cuenta con nueve instalaciones, cinco de ellas son generadoras de grandes volúmenes de aguas residuales industriales. El presente trabajo tiene el objetivo de presentar los resultados obtenidos en la evaluación de los parámetros físico-químico de los residuales líquidos del proceso productivo de conjugados monovalentes, para esto se muestrearon los residuales líquidos generados al final de cada etapa del proceso. Se determinaron los indicadores de contaminación: pH, temperatura, conductividad eléctrica, demanda química y bioquímica de oxígeno, fósforo total, nitrógeno total y sólidos sedimentables; los ensayos fueron realizados en el laboratorio de la Empresa Nacional de Servicios Técnicos de la Habana, acreditado para la realización de las caracterizaciones de aguas residuales. Los resultados fueron comparados con los límites máximos permisibles establecidos en la Norma Cubana NC-27:2012 de vertimiento de aguas residuales al alcantarillado, además se calculó el índice de biodegradabilidad. Se demostró que el pH, la conductividad eléctrica, demanda química de oxígeno y demanda bioquímica de oxígeno no cumplen con el vertido para la descarga al alcantarillado pudiendo impactar de manera negativa en los recursos hídricos(AU)

At present, the pollution of terrestrial waters is a serious environmental problem. The drug industry is one of those that produces a greater impact, due to the great variety of chemicals that can contribute to the water; its effluents generally have associated high non-biodegradable organic loads. The preservation of the quality of terrestrial waters is a subject regulated by legislation, where the characterization of wastewater is required before its discharge, since it allows evaluating the environmental impact it produces and designing the appropriate system for its treatment. The Finlay Vaccine Institute, belongs to the BioCubaFarma group, is a full cycle company, has nine facilities, five of them are generators of large volumes of industrial wastewater. The current work presents the results obtained in the evaluation of the physical-chemical parameters of the liquid waste from the production process of monovalent conjugates, for this the liquid waste generated at the end of each stage of the process was sampled. Pollution indicators were determined: pH, temperature, electrical conductivity, chemical and biochemical oxygen demand, total phosphorus, total nitrogen and sedimentable solids. The results were compared with the maximum permissible limits established in NC-27: 2012 for the discharge of wastewater. The biodegradability index was also calculated. It was shown that some of the determined parameters do not comply with the discharge to release to the sewer system, which could have a negative impact on water resources(AU)

Microbiological and chemical characteristics of beaches along the Taranto Gulf (Ionian Sea, Southern Italy).

Coastal habitats provide important ecosystem services, such as the maintenance of ecological sustainability, water quality regulation, nutrient recycling, and sandy beaches which are important areas for recreation and tourism. The quality of seawater is generally measured by determining the concentrations of Escherichia coli and intestinal Enterococci, which might be affected by the persistent populations of these bacteria in sand. Sand might thus be a significant source of pathogen exposure to beachgoers. The quality of coastal recreational waters can also be affected by eutrophication, water discoloration, and harmful algal blooms, which pose additional human health risks. Here, we conducted a monitoring of the beaches quality along the Taranto Gulf by determining the concentrations of fecal indicator organisms, as well as other parameters that are not traditionally measured (physicochemical parameters, Pseudomonas aeruginosa, and harmful microalgae), in shallow seawater and sand sampled from three beaches. The concentrations of bacteria were determined using both standard microbiological methods and the IDEXX system. Our results demonstrate the utility of measuring a greater number of parameters in addition to those conventionally measured, as well as the importance of assessing the health risks posed by the sand matrix. Additional work is needed to develop rapid analytical techniques that could be used to monitor the microbiological parameters of solid matrices.

Inequities in Drinking Water Quality Among Domestic Well Communities and Community Water Systems, California, 2011‒2019.

Objectives. To evaluate universal access to clean drinking water by characterizing relationships between community sociodemographics and water contaminants in California domestic well areas (DWAs) and community water systems (CWSs). Methods. We integrated domestic well locations, CWS service boundaries, residential parcels, building footprints, and 2013-2017 American Community Survey data to estimate sociodemographic characteristics for DWAs and CWSs statewide. We derived mean drinking and groundwater contaminant concentrations of arsenic, nitrate, and hexavalent chromium (Cr[VI]) between 2011 and 2019 and used multivariate models to estimate relationships between sociodemographic variables and contaminant concentrations. Results. We estimated that more than 1.3 million Californians (3.4%) use domestic wells and more than 370 000 Californians rely on drinking water with average contaminant concentrations at or above regulatory standards for 1 or more of the contaminants considered. Higher proportions of people of color were associated with greater drinking water contamination. Conclusions. Poor water quality disproportionately impacts communities of color in California, with the highest estimated arsenic, nitrate, and Cr(VI) concentrations in areas of domestic well use. Domestic well communities must be included in efforts to achieve California's Human Right to Water. (Am J Public Health. 2022;112(1):88-97. https://doi.org/10.2105/AJPH.2021.306561).

Study on the effect of front retaining walls on the thermal structure and outflow temperature of reservoirs.

The front retaining wall (FRW) is an effective facility of selective withdrawal. Previous research has not estimated the effect of FRWs on the thermal regimes of reservoirs and outflow temperature, which are crucial to reservoir ecology. For this purpose, taking the Dongqing Reservoir as a case study, a two-dimensional hydrodynamic CE-QUAL-W2 model was configured for the typical channel-type reservoir in the southwestern Guizhou Province, to better understand the influence of FRWs on the thermal structure and outflow temperature. The simulated data from January to September 2017 showed that FRWs can change the vertical temperature distribution during the stratification period, accelerate the upper warmer water release and thus decrease the strength of thermal stratification. The stratification structure changed from a single thermocline to double thermoclines in August. An FRW resulted in an average 11.8 m increase in the thickness of the hypolimnion and a 1.2°C decrease in the thickness of the thermocline layer. An FRW increased the outflow temperature by 0.4°C and raised the withdrawal elevation by 16 m on average. The longitudinal velocity increased compared with the non-FRW condition, while the maximum velocity position moved up. In addition, FRWs can continuously obtain surface warmer water without manual operation and have low investment and good construction conditions. This study can provide an available selective withdrawal idea for reservoirs with similar hydraulic conditions.

Drinking-water efficiency, cost of illness, and peri-urban society: An economic household analysis.

This study aims to measure the efficacy of drinking water in terms of the economic impacts and risk of illness involved in using perilous water sources. Socio-economic factors were also considered. A multidisciplinary approach was employed to analyze the data, including the cost of illness (COI), regression technique, and irrigation water efficiency methods. The primary data set consisted of 210 peri-urban and urban households. It was found that the average cost of illness was higher in peri-urban ($10.79 USD) areas, while willingness to pay for quality water was higher in urban residents. Social status, income, and family size was positively associated with the cost of illness, while education, the source of drinking water (ground water and others), and awareness about safe drinking were negatively associated with the cost of illness. Furthermore, urban residents were more efficient in terms of conveyance and water use. This is one of the first studies to apply irrigation water efficiency methods to measure drinking water efficiency. The results are timely and important with both practical and social implications, including guiding policy framework. It is suggested that family planning programs be made more effective to control family size. The filtration plants to enhance drinking water quality be installed in the central places of each town/division/union council. A public-private partnership could work to provide affordable quality drinking water.

Anthropogenic Influences on Physico-Chemical Quality, Fish and Macrophyte Diversities of River Adofi, Southern Nigeria.

<b>Background and Objective:</b> Freshwater systems support agriculture, industry and even human existence. Pollution due to human activities affect the quality of water bodies thereby threatening biodiversity. This study, therefore, investigated the anthropogenic influences on physico-chemical quality, fish and macrophyte diversities of River Adofi. <b>Materials and Methods:</b> Three sampling stations along River Adofi at Ejeme-Aniogor (Station 1), Utagba-Uno (Station 2) and Umuleke-Ossissa (Station 3) were selected based on ecological features and the presence of human activities. Water samples were collected fortnightly for 6 months and water quality was determined. Fish and macrophyte species were collected and diversity indices were calculated. <b>Results:</b> Physico-chemical parameters were significantly different (p<0.05) in all three stations except for magnesium, calcium and nitrate. Temperature, total dissolved solids, conductivity, COD, total alkalinity and magnesium were higher (p<0.05) in Station 2 at Utagba-Uno where a rubber factory effluent discharges into the river. Out of 15 families, 18 genera and 26 species of fish collected <i>Oreochromis </i>species were more abundant, followed by <i>Gymnarchus niloticus</i>. Mokochidae and Clariidae had higher diversities than other families. Macrophytes recorded were 53 taxa from 21 families and 33 genera with emergent and submerged life forms dominating. Poaceae dominated with nine species. Shannon index increased with increasing species richness and evenness with both fish and macrophytes evenly distributed. <b>Conclusion:</b> Lower diversity of fish species observed in Station 2 may be due to influences of effluent discharges into the river while domestic and agricultural activities enhanced abundance and diversity of fish and macrophytes at Station 3.

Applicability of Using Biological Indices to Assess Water Quality of the Nile Branches, Egypt.

<b>Background and Objective:</b> The Saprobity index (S) and the Wetland Zooplankton Index (WZI) are the most commonly used indices using zooplankton data to assess the water quality of many water bodies. However, these indices may be inadequate to assess the water quality of all freshwater bodies around the world. This study aims to evaluate the validity of these indices for assessing the water quality of the Nile branches (Damietta and Rosetta branches) as a case study. <b>Materials and Methods:</b> The validity of S and WZI is statistically tested against the Nile Chemical Pollution Index (NCPI) using linear regression analysis. The Physico-chemical parameters, zooplankton and Discriminant Analysis (DA) data show significant differences between the Damietta and Rosetta sites. <b>Results:</b> The results of both S and WZI do not coincide with those calculated with NCPI. The obtained S values show that all sites have poor water quality. On the other hand, the WZI values indicate that the Damietta branch sites in addition to the first two sites of the Rosetta branch (R₁ and R₂) have moderate water quality, while the other sites have poor water quality. <b>Conclusion:</b> Finally, the NCPI results show that the Rosetta branch sites are heavily polluted, while the Damietta sites are clean. This study concludes that S and WZI inaccurately describe the ecological status of the study area.

The importance of water quality in classifying basic water services: The case of Ethiopia, SDG6.1, and safe drinking water.

INTRODUCTION: Sustainable Development Goal (SDG) 6 aims to coordinate international efforts toward "clean water and sanitation." However, water contaminated with pathogenic bacteria or thermotolerant coliforms (TTC) will not achieve the SDG target of clean water in the lives of people around the world. The aim of this study is to assess the water quality parameters of basic water services in Amhara and Afar regions of Ethiopia as well as the role and importance of local managerial committees in ensuring basic water functionality. METHODS: This mixed methods research, conducted in January-June 2019, sampled 22 districts from food-insecure areas in the Amhara and Afar regions of Ethiopia. From the 22 districts, which represent nearly one third of all districts in each region, 111 water services classified as "basic" were randomly selected. For each selected water service, research included: water quality sample testing, visual observation of water services, interviews and focus group discussions with the associated water managerial committee members. Descriptive statistics frequency, percent, mean, median, standard deviations, normal tables, cross-tables and graphs are used to present the data. RESULTS: Although the international water standard for thermotolerant coliform (TTC) levels is 0 CFU/100ml, in our sample of 111 water services, the maximum TTC counts were 71 CFU/100 ml and the mean was 4 CFU/100 ml. Thermotolerant coliform counts were above the permissible standard values for nearly 40% (n = 111) of the basic water services. TTC was detected in 44 (39.64%) (n = 111) basic water services. Of these, 38 (34.23%) were operationally functional while 6 (5.41%) were not functional. Approximately one third of the basic water services sampled, deemed "functional" by international standards, do not provide potable water due to thermotolerant coliform (TTC) levels. CONCLUSION: Our findings from the Amhara and Afar regions of Ethiopia demonstrate that water quality parameters are not currently considered in classifying basic water services. This suggests that international efforts to address SDG 6 should incorporate water quality as a key parameter to better track international progress toward "clean water and sanitation" efforts. We discuss two potential pathways for stronger inclusion of water quality parameters in international definitions: (1) to mandate water quality within "functional" and "non-functional" definitions or (2) to add a ladder rung titled "safe basic water services" to the international drinking water ladder. Our findings from Ethiopia suggest that additional research should be undertaken in development contexts to assess whether or not "functional" basic water services provide safe drinking water to users.

Increased livestock weight gain from improved water quality in farm dams: A cost-benefit analysis.

Access to water is a critical aspect of livestock production, although the relationship between livestock weight gain and water quality remains poorly understood. Previous work has shown that water quality of poorly managed farm dams can be improved by fencing and constructing hardened watering points to limit stock access to the dam, and revegetation to filter contaminant inflow. Here we use cattle weight gain data from three North American studies to develop a cost-benefit analysis for the renovation of farm dams to improve water quality and, in turn, promote cattle weight gain on farms in south-eastern Australia. Our analysis indicated a strong likelihood of positive results and suggested there may be substantial net economic benefit from renovating dams in poor condition to improve water quality. The average per-farm Benefit-Cost Ratios based on deterministic assumptions was 1.5 for New South Wales (NSW) and 3.0 for Victoria in areas where rainfall exceeds 600mm annually. Our analyses suggested that cattle on farms in NSW and Victoria would need to experience additional weight gain from switching to clean water of at least 6.5% and 1.8% per annum respectively, to break even in present value terms. Monte Carlo simulation based on conservative assumptions indicated that the probability of per-farm benefits exceeding costs was greater than 70%. We recommend localised experiments to assess the impact of improved water quality on livestock weight gain in Australian conditions to confirm these expectations empirically.

Integrated assessment modeling reveals near-channel management as cost-effective to improve water quality in agricultural watersheds.

Despite decades of policy that strives to reduce nutrient and sediment export from agricultural fields, surface water quality in intensively managed agricultural landscapes remains highly degraded. Recent analyses show that current conservation efforts are not sufficient to reverse widespread water degradation in Midwestern agricultural systems. Intensifying row crop agriculture and increasing climate pressure require a more integrated approach to water quality management that addresses diverse sources of nutrients and sediment and off-field mitigation actions. We used multiobjective optimization analysis and integrated three biophysical models to evaluate the cost-effectiveness of alternative portfolios of watershed management practices at achieving nitrate and suspended sediment reduction goals in an agricultural basin of the Upper Midwestern United States. Integrating watershed-scale models enabled the inclusion of near-channel management alongside more typical field management and thus directly the comparison of cost-effectiveness across portfolios. The optimization analysis revealed that fluvial wetlands (i.e., wide, slow-flowing, vegetated water bodies within the riverine corridor) are the single-most cost-effective management action to reduce both nitrate and sediment loads and will be essential for meeting moderate to aggressive water quality targets. Although highly cost-effective, wetland construction was costly compared to other practices, and it was not selected in portfolios at low investment levels. Wetland performance was sensitive to placement, emphasizing the importance of watershed scale planning to realize potential benefits of wetland restorations. We conclude that extensive interagency cooperation and coordination at a watershed scale is required to achieve substantial, economically viable improvements in water quality under intensive row crop agricultural production.

Efficiency of Treatment Plant and Drinking Water Quality Assessment from Source to Household, Gondar City, Northwest Ethiopia.

Introduction: Access to safe drinking water is essential to health, and it is a basic human right. However, drinking water treatment plant efficiency and its water quality are not well investigated in low-income countries including Ethiopia. Methods: A laboratory-based cross-sectional study was conducted among 75 water samples. Data analysis was carried out using SPSS version 22 to generate descriptive statistics, and one-way ANOVA was used to test statistically significant difference. Results: Physicochemical qualities of the water samples from tap water sources were found to be pH (6.88 ± 0.05), turbidity (5.15 ± 0.006 NTU), electrical conductivity (170.6 ± 0.1 µS/cm), residual chlorine (0.19 ± 0.003 mg/L), and fluoride (1.17 ± 0.009 mg/L). The removal efficiency of turbidity, total hardness, and nitrate was found to be 94.4%, 52.3%, and 88.7%, respectively. Removal efficiency of the treatment plant for total coliforms up to 91.6% (15 ± 0.26 CFU/100 mL in tap water) and faecal coliforms up to 99% (1.51 ± 0.03 CFU/100 mL in tap water) was recorded. Parameters of pH, temperature, and faecal coliform were statistically significant different at p < 0.05 in tap water source. The overall efficiency of the treatment plant (68.5%) and the water quality index (76) were recorded. Conclusion: Based on the results, some of the investigated parameters of water quality (turbidity, residual chlorine, total coliform, and faecal coliform) were found to be not within the permissible limits of WHO guideline values for drinking water quality. The water quality index of the water samples was categorized under good water quality. To adequately treat drinking water and improve the treatment plant, adequate preliminary treatments like screening to reduce the incoming organic loading, proper chlorination of the drinking water system, and frequent monitoring and maintenance of the treatment plant system are required.

Water quality criteria and ecological risk assessment for ammonia in the Shaying River Basin, China.

Current Chinese surface water environmental quality standard GB3838-2002 for ammonia fails to take water quality factors and native organism distributions in different basins into consideration. In this study, ammonia toxicity tests were performed using three aquatic organisms native to the Shaying River Basin (China). Published ammonia toxicity data with pH and temperature, and toxicity data acquired in this study were used to establish water quality criteria. The final criterion maximum concentration (CMC) and criterion continuous concentration (CCC) for the Shaying River Basin were 5.09 and 1.36 (mg total ammonia nitrogen (TAN))/L (pH 7 and 20 °C), respectively. In addition, based on the corresponding relationship between ammonia toxicity and temperature and pH, the ecological risk assessment of ammonia was conducted in different seasons for the Shaying River using a tiered approach of both hazard quotient (HQ) and the joint probability (JPC) methods. Two methods gave consistent results: the ecological risks of ammonia to aquatic species in the Shaying River Basin were severe and the risk could be ranked as wet season > flat season > dry season. It is therefore indicating that monitoring, evaluation, and early warning of ammonia pollution need to be taken to prevent and control the risks posed by ammonia pollution, especially for wet season (because of high temperatures and pH) or flat season (because of high pH values). We hope the present work could provide valuable information to manage and control ammonia pollution in the Shaying River Basin.

Health Technology Assessment of a new water quality monitoring technology: Impact of automation, digitalization and remoteness in dialysis units.

BACKGROUND: Water quality monitoring at the dialysis units (DU) is essential to ensure an appropriate dialysis fluid quality and guarantee an optimal and safe dialysis treatment to patients. This paper aims to evaluate the effectiveness, economic and organizational impact of automation, digitalization and remote water quality monitoring, through a New Water Technology (NWT) at a hospital DU to produce dialysis water, compared to a Conventional Water Technology (CWT). METHODS: A before-and-after study was carried out at the Hospital Clínic Barcelona. Data on CWT was collected during 1-year (control) and 7-month for the NWT (case). Data on water quality, resource use and unit cost were retrospective and prospectively collected. A comparative effectiveness analysis on the compliance rate of quality water parameters with the international guidelines between the NWT and the CWT was conducted. This was followed by a cost-minimization analysis and an organizational impact from the hospital perspective. An extensive deterministic sensitivity analysis was also performed. RESULTS: The NWT compared to the CWT showed no differences on effectiveness measured as the compliance rate on international requirements on water quality (100% vs. 100%), but the NWT yielded savings of 3,599 EUR/year compared to the CWT. The NWT offered more data accuracy (daily measures: 6 vs. 1 and missing data: 0 vs. 20 days/year), optimization of the DU employees' workload (attendance to DU: 4 vs. 19 days/month) and workflow, through the remote and continuous monitoring, reliability of data and process regarding audits for quality control. CONCLUSIONS: While the compliance of international recommendations on continuous monitoring was performed with the CWT, the NWT was efficient compared to the CWT, mainly due to the travel time needed by the technical operator to attend the DU. These results were scalable to other economic contexts. Nonetheless, they should be taken with caution either when the NWT equipment/maintenance cost are largely increased, or the workforce involvement is diminished.

Hydrochemical characteristics and nitrate health risk assessment of groundwater through seasonal variations from an intensive agricultural region of upper Krishna River basin, Telangana, India.

Seasonal variations in hydrogeochemical characteristics of groundwater were assessed from an intensive agricultural region to identify contaminants of concern that are a potential risk to human health. A total of 116 groundwater samples were collected grid-wise from an intensive agricultural region of confined Wanaparthy watershed to evaluate seasonal variations in hydrogeochemical processes of dissolved ions, nitrate health risk assessment and water quality during pre-monsoon (PRM) and post-monsoon (POM) seasons. The major ions concentration found in ascending order as PRM: F- < NO3-< SO42-< HCO3-< Cl- and K+< Mg+2< Ca+2< Na+ while POM: F- < NO3-< SO42-< Cl-< HCO3- and K+< Ca+2< Mg+2< Na+ respectively. Piper diagram for water-types shows PRM; Na-Cl type (70.68%) while POM; Ca-Mg-Cl type (39.66%) and Ca-HCO3 type (31.03%). Gibbs diagram explained the favorable environmental conditions as rock and evaporation dominance in both seasons. Spatial distribution map shows samples with higher and above permissible limits are found at/near to adjoining to higher-order streams and streams origin. As per the water quality index (WQI), 36.21% (PRM) and 60.34% (POM) fall in poor to unfit for drinking class. Hazard quotient (HQ) values of nitrate reach as high as for infants 1.31E + 01, children 1.23E + 01 and adults 4.68E + 00 respectively. Subsequently, HQ>1 with 68.97% of infants and 72.41% of children are in danger for non-carcinogenic ingestion of nitrate contaminated groundwater than in adults.

Acute viral hepatitis E complicated with acute pancreatitis in an immunocompetent adult.

Acute viral hepatitis has been associated with several extrahepatic complications. Fulminant liver failure secondary to acute viral hepatitis may be complicated by acute pancreatitis. However, in the setting of benign viral hepatitis, in the absence of liver failure, association of pancreatitis is uncommon, that too in an otherwise immunocompetent individual. The exact mechanism of hepatitis-related pancreatitis remains elusive. Proposed mechanisms include immune-mediated injury against infected pancreatic acinar cells, oedema of the ampulla of Vater and release of lysosomal enzymes from the liver. A high index of clinical suspicion is needed in any case of viral hepatitis with severe abdominal pain to recognise acute pancreatitis as a possible complication, which may increase both morbidity and mortality if unrecognised. Herein, we report a case of a young man presenting with acute viral hepatitis due to hepatitis E infection, complicated by acute pancreatitis.

Sensitivity of freshwater organisms to cadmium and copper at tropical temperature exposures: Derivation of tropical freshwater ecotoxicity thresholds using species sensitivity distribution analysis.

Tropical freshwater ecosystems are increasingly influenced by chemical stressors including heavy metals posing threats to biodiversity. Adequate ecotoxicity data are not available for native tropical freshwater species for deriving water quality guidelines and for conducting ecological risk assessments. Objectives of this study were (i) to generate freshwater ecotoxicity data for cadmium (Cd) and copper (Cu) for tropical temperature exposures using standard laboratory bioassays with selected freshwater species and (ii) to derive ecotoxicity thresholds (protection concentrations, PC) for tropical freshwater life based on 'tropical temperature-specific exposure' ecotoxicity data. Estimated final chronic toxicity values of the six species tested in the study indicate that the most sensitive species was the crustacean, Moina macrocopa for both metals while the algae Chlorella vulgaris and the plant Lemna perpusilla showed highest tolerance to Cd and Cu respectively. Tropical temperature-specific exposure (25-30 °C) was used as the decision criterion for deriving ecotoxicity thresholds of Cd and Cu for protection of tropical freshwater life based on species sensitivity distribution analysis of the final chronic toxicity data sets which included published toxicity data of selected species in addition to the six species tested in this study. The derived PC99, PC95, PC90 and PC80 values for protection of tropical freshwater life under chronic exposure are 0.5, 1.2, 1.9 and 3.5 µg/L for Cd and 0.34, 0.84, 1.4 and 2.6 µg/L for Cu respectively. These derived threshold chronic values (PC99 and PC95) indicate that the established freshwater quality guidelines based on temperate species for Cu may not provide sufficient protection of the freshwater species in the tropics while the available freshwater guidelines for Cd would provide adequate protection for the tropical freshwater species. The tropical freshwater ecotoxicity thresholds derived in this study may be used with some caution as reference points for site specific ecological risk assessments in the tropics.

Performance-based risk-sharing agreements in renal care: current experience and future prospects.

INTRODUCTION: Performance-based risk-sharing agreements (PBRSAs), between payers, health care providers, and technology manufacturers can be useful when there is uncertainty about the (cost-) effectiveness of a new technology or service. However, they can be challenging to design and implement. AREAS COVERED: A total of 18 performance-based agreements were identified through a literature review. All but two of the agreements identified were pay-for-performance schemes, agreed between providers and payers at the national level. No examples were found of agreements between health care providers and manufacturers at the local level. The potential for these local agreements was illustrated by hypothetical case studies of water quality management and an integrated chronic kidney disease program. EXPERT OPINION: Performance-based risk-sharing agreements can work to the advantage of patients, health care providers, payers, and technology manufacturers, particularly if they facilitate the introduction of technologies or systems of care that might not have been introduced otherwise. However, the design, conduct, and implementation of PBRSAs in renal care pose a number of challenges. Efforts should be made to overcome these challenges so that more renal care patients can benefit from technological advances and new models of care.

Potential Human Health Risks Due to Groundwater Fluoride Contamination: A Case Study Using Multi-techniques Approaches (GWQI, FPI, GIS, HHRA) in Bilate River Basin of Southern Main Ethiopian Rift, Ethiopia.

The main focus of the present research was to examine the appropriateness of groundwater resources for drinking purposes in the Bilate River Basin of Southern Main Ethiopian Rift, Ethiopia. The groundwater quality index (GWQI), fluoride pollution index (FPI), and human health risk were used to examine the human health risk factors associated with the intake of high fluoride groundwater. For this purpose, 29 groundwater samples were collected from the existing wells and were analyzed for various physicochemical parameters. The dominant cation was Na+, followed by Ca2+, Mg2+, and K+. The dominant anion was HCO3-, followed by Cl-, SO42-, and F-. The Gibbs plot shows that rock-water interactions are the dominant factor controlling the groundwater chemistry. By using the GWQI, the quality of groundwater samples was 31% excellent, 21% good, 31% poor, and 17% very poor. The fluoride concentration in groundwater ranges from 0.2 to 5.60 mg/L (mean, 2.10 mg/L). 59% (i.e., 17 wells) of the groundwater samples were not suitable for drinking, because they surpassed the drinking water quality limit of 1.5 mg/L. The remaining 41% (i.e., 12 wells) of the samples were suitable for drinking. The FPI indicates that 51.72% of the wells were highly polluted by fluoride. The noncarcinogenic health risk varies from 0.75 to 8.44 for children (83%), 0.34-3.84 for women (62%), and 0.27-3.01 for men (52%), which indicates that children are at higher health risk than women and men due to the physiological condition and the rates of ingestion.

Assessment of water quality in Aguieira reservoir: Ecotoxicological tools in addition to the Water Framework Directive.

To assess the ecological potential (EP), the Water Framework Directive (WFD) uses specific parameters but ignores ecosystem functioning and individual/subindividual biological responses. The heavily modified water bodies (reservoirs) are strongly influenced by human activities that promote their imbalance, with a loss or compromise the biodiversity and the functioning of these ecosystems. This work aims to determinate the EP according physical, chemical and biological parameters of WFD and evaluate the functionality and sensitivity of ecotoxicological tools in the evaluation of water quality of Aguieira reservoir. Four sampling sites were defined in Aguieira reservoir and sampling was conducted in autumn 2018, spring and autumn 2019. WFD showed overall that Aguieira reservoir presented moderate EP. The autumn samples and the two reservoir upstream sites had the worst classification. These results were complemented by a set of ecotoxicological assays (growth inhibition of Raphidocelis subcapitata and Spirodela polyrhiza, and feeding rate of Daphnia longispina) using three natural water treatments. R. subcapitata was the most sensitive species, indicating the presence of a risk that is not detected by chemical analysis, nor by organisms of different trophic levels. D. longispina only showed sensitivity in A3 and A4 in autumn, however this results was difficult to interpret since no reason can be observed to respond the F1 lower feeding rate observed in almost sites. S. polyrhiza, as well as the total chlorophyll, lipid peroxidation, and proline content did not show sensitivity, since no discrimination among the water treatments were recorded. The relevance of bioassays is associated with the fact that an integrated response to a complex mixture can be obtained, which can contain more substances than the measured ones. Thus, we may conclude that WFD are insufficient to draw conclusions about water quality, and the growth inhibition of Raphidocelis subcapitata assay is an important parameter to complement the WFD. In addition, species of different trophic levels are recommended for ecotoxicological analyses due to differences in species sensitivities.