Investigation of drinking water quality and population health risk assessment in a poor rural area

BACKGROUND: The quality and safety of drinking water directly affect the health of the local population. However, due to the limited conditions in poor rural areas, the safety of drinking water is more prominent. OBJECTIVE: It aimed to ensure the safety of drinking water quality and population health in poor rural areas. METHODS: A rural poor area was taken as an example, the drinking water plants were monitored during wet season and dry season, respectively, and the water quality indicators of rural drinking water in the city in 2019 were detected and analyzed. Finally, based on the non-carcinogenic risk and carcinogenic risk evaluation model proposed, the health risk assessment of chemical pollutants in drinking water was carried out. RESULTS: In 2019, the qualified rate of drinking water in rural areas of the city was generally low. The average annual carcinogenic risk of drinking water in poor rural areas of the city was 1.57×10–6 (a–1), and the average annual non-carcinogenic risk was 5.38×10–9 (a–1). CONCLUSION: The health risk assessment model proposed can well evaluate the health risks of drinking water. The research provides a scientific basis for the risk management of drinking water of relevant departments.

The rationale for introducing the indices «Generalized coliform bacteria» and «Escherichia coli» into the scheme of sanitary and microbiological control of water quality as indices of fecal contamination

Introduction. The increasing bacterial contamination of water bodies requires an increase in water quality control’s reliability to ensure epidemic safety against waterborne infections. Therefore, researchers in both Russia and Europe came to the conclusion that it is necessary to search for indicator microorganisms that can more accurately suggest the presence of pathogens. microorganisms in water than traditional indicators. The aim of the study was to justify the introduction of indicator indices of fecal contamination “generalized coliform bacteria” and Escherichia coli to assess the safety of drinking water Material and methods. The article provides an analysis of domestic and international regulatory documents and literary materials regulating the quality of drinking water in terms of sanitary and microbiological indicators and assessment criteria. The results of many years of experimental and field research carried out by research organizations and practical organizations of the Federal Service for Supervision of Consumer Rights Protection and Human Welfare are presented. Results. On the territory of Russia, “general coliform bacteria,” is one of the indicator indices chosen according to the fermentation of lactose, determine the safety of drinking water. The water does not take into account pathogenic bacteria (Salmonella, Shigella) and a number of lactose-negative opportunistic bacteria, causative agents of intestinal infections. The study of microorganisms isolated from the feces of patients confirms the frequency of occurrence of lactose-negative microorganisms to varying from 20 to 100% of strains. With an annual trend towards a decrease in the percentage of non-standard drinking water samples in terms of microbiological indices, general intestinal infections (GII) of unknown etiology increase, i.e. risk of GII. If the quality of drinking water does not correspond to thermotolerant coliform bacteria (TCB), 95% of samples contain E. coli. Therefore, the determination of E. coli more reliably indicates the intake of fresh fecal contamination and provides efficiency in taking measures to eliminate an unfavorable situation than TCB. Conclusion. Reasons are given for the introduction of more reliable microbiological indicators of water safety control, such as - “generalized coliform bacteria” with the preservation of the abbreviation GCB, combining both lactose-positive and lactose-negative bacteria, determined by the sign of glucose fermentation, negative oxidase test and negative stain according to Gram and E. coli as an indicator of recent faecal contamination, which will allow the assessment of water quality for a wide range of bacteria of the order Enterobacterials, corresponding to the modern taxonomy of Enterobacteriaceae NCBI, will ensure harmonization with international requirements and the safety of drinking water for the population.

Research of regularities of formation of health-improving antioxidant electron-donor properties of functional drinking water modified with ascorbic and citric acids

Drinking water is a food of special physiological value, as evidenced by a critically short for health and life endurance of complete dehydration of the body (no replenishment of drinking water) in 9–10 days along with 45–49 days of life without food. However, even without extreme circumstances, without any shortage of drinking water and food, the quality of the latter has a serious impact on human health. For some time, as environmental pollution increased, the efforts of hygienists were aimed at ensuring the safety of drinking water through its appropriate physical and chemical treatment. Then came the realization that the microbiological and chemical safety of drinking water does not guarantee its inherent in the best samples of natural water physiological value. The meaning of this newly introduced into the normative circulation of the concept is the awareness of the importance of water as a source of replenishment of the body physiologically necessary for normal life minerals and trace elements. Subsequently, nutrients were synthesized that are produced by the body itself and the normal content of which in cells is critical for life. Natural sources of replenishment of the body with nutrients (good food and especially vegetables, berries, fruits, etc.) for various reasons are not always available to many people, so specially prepared drinking (functional) water has gained in recent years growing popularity and high health value. The presented results of research of functional water on the basis of ascorbic and citric acid are our contribution to the development of methods of health nutrition. The influence of functional water with acquired antioxidant properties on the human body is substantiated. The developed water provides drinking water with a pleasant harmonious taste, which has a tonic and healing effect, increasing the body's resistance to fatigue and stress. The development relates to the field of production of soft drinks, in particular drinking water.

Method for Determining the Probability of a Lack of Water Supply to Consumers

The water distribution subsystem is the most failing subsystem included in the water supply system. One of the main consequences of water supply failures is the lack of water supply to consumers, which is always very onerous. The paper presents a method of determining the conditional probability that a break in the supply of water to consumers of a certain duration will be caused by a specific type of failure. The result of the work was to identify water supply network failures that result in the longest water supply suspension time. The method was presented on a real water supply system. In order to reduce the incidence of long-term interruptions in water supply, water supply companies should mainly continue replacing gray cast iron pipes with thermoplastic materials. Actions taken to increase the safety of drinking water supply meet the current standards for the safety of drinking water, developed by the World Health Organization and the European Union.

Does Training Improve Sanitary Inspection Answer Agreement between Inspectors? Quantitative Evidence from the Mukono District, Uganda

Sanitary inspections (SIs) are checklists of questions used for achieving/maintaining the safety of drinking-water supplies by identifying observable actual and potential sources and pathways of contamination. Despite the widespread use of SIs, the effects of training on SI response are understudied. Thirty-six spring supplies were inspected on two occasions, pre- and post-training, by an instructor from the research team and four local inspectors in the Mukono District of Uganda. SI score agreement between the instructor and each inspector was calculated using Lin’s concordance correlation coefficient. Average SI score agreement between the instructor and all inspectors increased post-training for the Yes/No answer type (0.262 to 0.490). For the risk level answer type (e.g., No, Low, Medium, High), average SI score agreement between the instructor and all inspectors increased post-training (0.301 to 0.380). Variability of SI scores between the four inspectors was calculated using coefficient of variation analysis. Average SI score variability between inspectors reduced post-training for both answer types, Yes/No (21.25 to 16.16) and risk level (24.12 to 19.62). Consistency of answer agreement between the four inspectors for each individual SI question was calculated using index of dispersion analysis. Average answer dispersion between inspectors reduced post-training for both answer types, Yes/No (0.41 to 0.27) and risk level (0.55 to 0.41). The findings indicate that training has a positive effect on improving answer agreement between inspectors. However, advanced training or tailoring of SI questions to the local context may be required where inconsistency of responses between inspectors persists, especially for the risk level answer type that requires increased use of inspector risk perception. Organisations should be aware of the potential inconsistency of results between inspectors so that this may be rectified with appropriate training and, where necessary, better SI design and customisation.

Total and Specific THMs’ Prediction Models in Drinking Water Pipe Networks

Although disinfection is a crucial process for the safety of drinking water, it is responsible for the formation of disinfection by-products (DBPs) being accused of severe health problems. The present study presents the development of models predicting trihalomethanes (THMs) in a drinking water supply system in Greece. Although some of the developed models can be used for the prediction of THMs, they are site-specific and cannot be used extensively.

Potential impact of floating solar panels on water quality in reservoirs; pathogens and leaching

Application of floating solar panels is especially suited for the Netherlands, given the limited availability of land (surface area). Evides water company owns and operates several open storage reservoirs which can be used for installation of these panels, but the installations could affect the local environment, naturally occurring processes and water quality. In this research, we evaluate leaching of various substances and possible effects based on a theoretical approach following the Analysis of Microbiological Safety of Drinking water (AMSD method). Besides the water quality issues, the ongoing research at Evides will focus on the effect of the floating solar installation on algae, microbiological and chemical parameters, birds, aquatic flora and fauna, and also look into possibilities of applying alternative storage possibilities using hydrogen.