WHO Guidelines For Drinking Water Quality Research Articles

Drinking water quality and associated factors in Bahir Dar City and the surrounding rural areas, Northwest Ethiopia: a community-based cross-sectional study

Abstract In low-income countries like Ethiopia, waterborne illnesses have posed serious public health problems. This study aimed to evaluate drinking water quality (DWQ) and associated factors in Bahir Dar City and the surrounding rural areas in northwest Ethiopia. A cross-sectional study was conducted from January to June 2022 to determine coliform counts and basic physicochemical parameters from the drinking water samples (DWS) collected from urban, peri-urban, and rural sites. A total of 180 DWS were collected from water collection points and households' containers. Potentially pathogenic bacteria were also isolated from fecal coliform (FC)-positive samples and their antibiotic susceptibility profiles were determined. Moreover, the risk factors associated with water quality were assessed. The water quality test results were evaluated against the WHO guidelines for DWQ. Based on the results of this study, only 16.7 and 73.88% of samples met the standards for total coliform and FC, respectively. Moreover, 95.4 and 43% of the isolated bacteria were resistant at least to one of the commonly used antibiotics and multidrug-resistant, respectively. Educating the public on proper drinking water handling, appropriate treatment, and waterline maintenance are needed to safeguard the community from waterborne diseases.

Groundwater fluoride and nitrate contamination and associated human health risk assessment in South Punjab, Pakistan.

Consumption of high fluoride (F-) and nitrate (NO3-) containing water may pose serious health hazards. One hundred sixty-one groundwater samples were collected from drinking wells in Khushab district, Punjab Province, Pakistan, to determine the causes of elevated F- and NO3- concentrations, and to estimate the human health risks posed by groundwater contamination. The results showed pH of the groundwater samples ranged from slightly neutral to alkaline, and Na+ and HCO3- ions dominated the groundwater. Piper diagram and bivariate plots indicated that the key factors regulating groundwater hydrochemistry were weathering of silicates, dissolution of evaporates, evaporation, cation exchange, and anthropogenic activities. The F- content of groundwater ranged from 0.06 to 7.9mg/L, and 25.46% of groundwater samples contained high-level fluoride concentration (F- > 1.5mg/L), which exceeds the (WHO Guidelines for drinking-water quality: incorporating the first and second addenda, WHO, Geneva, 2022) guidelines of drinking-water quality. Inverse geochemical modeling indicates that weathering and dissolution of fluoride-rich minerals were the primary causes of F- in groundwater. High F- can be attributed to low concentration of calcium-containing minerals along the flow path. The concentrations of NO3- in groundwater varied from 0.1 to 70mg/L; some samples are slightly exceeding the (WHO Guidelines for drinking-water quality: incorporating the first and second addenda, WHO, Geneva, 2022) guidelines for drinking-water quality. Elevated NO3- content was attributed to the anthropogenic activities revealed by PCA analysis. The high levels of nitrates found in the study region are a result of various human-caused factors, including leaks from septic systems, the use of nitrogen-rich fertilizers, and waste from households, farming operations, and livestock. The hazard quotient (HQ) and total hazard index (THI) of F- and NO3- showed high non-carcinogenic risk (> 1) via groundwater consumption, demonstrating a high potential risk to the local population. This study is significant because it is the most comprehensive examination of water quality, groundwater hydrogeochemistry, and health risk assessment in the Khushab district to date, and it will serve as a baseline for future studies. Some sustainable measures are urgent to reduce the F- and NO3- content in the groundwater.

S-17-04 Updating the WHO Guidelines for drinking-water quality – how are chemicals prioritized?

S-17-04 Updating the WHO Guidelines for drinking-water quality – how are chemicals prioritized?

Low Concentrations of Silver Nanoparticles Inhibit Spore Germination and Disturb Gender Differentiation of Ceratopteris thalictroides (L.) Brongn

Because of their excellent antibacterial properties, silver nanoparticles (AgNPs) are widely used in all walks of life, which has caused them to be discharged into aquatic environments with possible negative effects on aquatic plants. In the present study, we used an aquatic fern, Ceratopteris thalictroides, as a model to investigate the effects of AgNPs on its spore germination, gametophytes, sex differentiation, and growth. The results demonstrated that AgNPs significantly inhibited spore germination of C. thalictroides at a AgNP concentration higher than 0.02 mg/L. Additionally, we found sex-dependent effects of AgNPs on the development and growth of the gametophyte of C. thalictroides. The proportion of hermaphrodites in the gametophytes and the area of gametophytes significantly decreased under AgNP treatment, while no significant effect was observed in the male gametophytes. Using the AgNP filtrate (without nanoparticles) and AgNPs plus cysteine (Ag+ chelator), we found that the release of Ag+ from nanoparticles was not the cause of the toxicity of AgNPs on C. thalictroides. The EC50 of AgNPs on spore germination was 0.0492 mg/L, thus indicating an ecological risk of AgNPs on this species even at concentrations lower than the Ag element concentration of the WHO guidelines for drinking-water quality.

Evaluation\xa0of\xa0groundwater\xa0quality\xa0and\xa0its\xa0impact\xa0on\xa0human\xa0health: a case\xa0study\xa0from\xa0Chotanagpur\xa0plateau\xa0fringe\xa0region\xa0in\xa0India

Groundwater is a vital and purest form of natural resource. In the recent years, various anthropogenic causes threat its natural quality. Therefore, its suitability for drinking, irrigation and other purposes make doubtful conditions of human well-being, especially in developing countries. In this present study, groundwater quality was evaluated for drinking, irrigation and human health hazard purposes particularly in Chotanagpur plateau fringe of India. In total, 58 water samples were collected from different locations in pre-monsoon (February–March 2020) and post-monsoon (October–November 2020) seasons to delineate seasonal variation of groundwater quality according to as reported by WHO (WHO guidelines for drinking-water quality, World Health Organization, Geneva, 2011) guidelines. Groundwater Quality Index (GWQI) and Heavy metal Pollution Index (HPI) have been applied to assess the suitability of drinking purposes. Irrigation parameters (SAR, SSP, MAR, PI, KR) showed the significant deterioration of water quality in pre-monsoon than post-monsoon period. Major cations (such as sodium, calcium) and major anions (such as bicarbonate, nitrate and fluoride) exceeded their standard limit in both the seasons. Non-carcinogenic health risk is found due to heavy metal contamination through drinking water. The health risk index was higher for children in comparison with adults. This research finding can definitely help to planners and administrators for immediate decision making regarding public health (for groundwater quality improvement).

Drinking water quality assessment from water dispensers in an educational institution

Abstract Water dispensers are commonly used in educational institutions in developing countries. Assessment of factors influencing drinking water quality from this source is important due to its potential to cause waterborne diseases and other health risks. This study aimed to assess microbial contamination and the factors affecting drinking water quality from water dispensers at Walailak University, Southern Thailand. Drinking water samples from 60 water dispensers of different type-brands were collected and tested for physicochemical and microbiological parameters by following WHO Drinking Water Quality guidelines. Also evaluated by questionnaires were hygienic standards and maintenance of water dispensers. The physicochemical analysis of all water samples did not exceed the reference values of the drinking water standard; the hardness value in only 13.3% of samples was slightly higher than the reference limit. The microbiological results indicated that total coliform and fecal coliform bacteria were found in 16.67% and 8.33% of total samples, respectively. Escherichia coli was not detected in any of the water samples. The assessment of factors influencing drinking water quality, location and pathogen source around water dispensers, hygienic environment, and maintenance of water dispensers had a significant effect on drinking water quality.

THE AMOUNT AND SPECIATION OF TRACE ELEMENTS TRANSPORTED FROM RICE FIELD TO CANAL DURING A FLOODING EVENT

Trace element pollution of soils, sediments and surface water can pose a risk for the local population and the environment of Vietnam. Rice fields can be affected by storm events, which cause the release of trace elements into surface water and transport them into drinking wells. The aim of this study was to investigate if dissolved and suspended As, Pb and Zn concentrations in surface water of a paddy rice fields and an irrigation canals increased during a flooding event and exceed the Vietnamese Surface Water Quality Standards and WHO Guidelines for Drinking-water Quality. The study site is a rice field area in the Thanh Hoa province in Central Vietnam, which experiences an average of 2.4 storms every year causing overflow of streams and low-order canals. Concentrations of As increased during the flooding event with dissolved As being the prevailing fraction, which followed a late flush behavior. Lead showed no significant difference in concentration over time. Zn concentrations only increased significantly in the canal upstream the field in the morning of the first day. Suspended Zn dominated at that time, following the first flush behavior of TSS concentrations. Concentrations of As, Pb and Zn did not exceed the Vietnamese Surface Water Quality Standards or WHO Guidelines for Drinking-water Quality at any time and they are therefore of no concern for the health of the local population

Public health risk assessment from drinking water from vending machines in Seri Kembangan (Malaysia)

This study investigated the public health risk linked with microbial quality of drinking water from vending machines in Seri Kembangan city (Malaysia) using epidemiological and Quantitative Microbial Risk Assessment (QMRA) approaches. This study was also conducted to understand associations between reported health symptoms and daily water intake information. Following WHO guidelines on water safety, QMRA were performed was to estimate burden of disease from E. coli from water vending machines. Triplicate drinking water samples from water vending machines were collected from six sampling areas around the city, analysed for E. coli, information of health symptoms and daily water intake was obtained from 121 respondents by questionnaires. The results indicated the highest numbers of E. coli levels were found in Seri Serdang (45–68 CFU/100 mL) and Taman Pinggiran Putra (45–62 CFU/100 mL). Escherichia coli levels in drinking water samples from water vending machines obtained from Seri Serdang, Taman Pinggiran Putra, Taman Equine, Balakong and Serdang Jaya exceeded both Malaysian Drinking Water Quality and WHO Drinking Water Quality guidelines. Reported health symptoms were only significantly linked to brand which likely to be associated with regular maintenance of water vending machine. All the drinking water samples from water vending machines except from Lestari Perdana have exceeded the health based target outcomes by QMRA. Combination of epidemiology and quantitative microbial risk assessment have provided a clear understanding of public health risks and gateway for a better management of water vending machines.

Assessment of drinking water quality and its health impact on local community in coastal belt Karachi

For survival of human beings clean water is an essential commodity whereas contamination in drinking water threatens to mankind. The main cause of water contamination is social and development activities of human being along with increasing population. The community in the study area has acute shortage of drinking water along with about 40 to 60% has no access to safe drinking water. This study indicates drinking water quality of two major sources of coastal belt of Karachi one is supplied by Karachi Water & Sewerage Board (KWSB) as tap water and the other through groundwater. The physicochemical analysis was carried out by following the standard methods for checking the quality of drinking water. The analyzed results showed that the quality of groundwater was unfit as potable water. The most critical situation was observed as high level of contamination followed by high turbidity and increased salinity levels. TDS in surface water were found 12% above and TDS in groundwater was 20% below the National Drinking Water Quality Standards (NDWQS) of Pakistan as well as the permissible WHO drinking water quality guidelines.

Microbiological contamination of water pans in Baringo County

Water pans constitute the main source of rural water supply in Baringo County. This study sought to assess the spatial-temporal variation of total coliforms, Escherichia coli, Fecal streptococcus and Salmonella species in the water pans. A sanitary survey was conducted to observe the potential sources of microbial contamination on the water pans. Water was sampled from one protected and five unprotected water pans (n = 6) in the study area for a period of 4 months (June–October 2015). A total of 72 water samples were sampled in triplicate from the water pans for microbial analyses, membrane filtration technique was used in assaying for microbial counts of total coliforms, E. coli, F. streptococcus and Salmonella species in water samples. The results show that there was a significant spatial variation in F. streptococcus amongst the protected and the unprotected water pan sampled sites (p = 0.008), and there was a statistically temporal significant difference (p = 0.001) for total coliforms and Salmonella species during the dry seasons, respectively. Given the prevalence of the selected diseases causing pathogens in water above the WHO drinking water quality guidelines, households are advised to treat the water before use.

The Influence of Anions on the Release of Ag(I) Ions from Silver Nanoparticles (AgNPs)

Silver nanoparticles (AgNPs) are widely being incorporated into products such as socks [1, 2], sports wears and wound dressings [3, 4] to serve as antibacterials and to inhibit unwanted odours. As these products are washed, the silver nanoparticles leach out, dispersing in water where they may release silver ions. Although the only contraindication of high levels of silver in humans is argyria [5], it is said to be very toxic to aquatic organisms that make up the base of a series of food chains. In this study, silver nanoparticles were synthesised by the citrate reduction method following the procedure of Lee and Meisel [6]. The nanoparticles were prepared in the presence of various anions and in pure water in order to examine the effect of the medium on the release of Ag(I). AgNPs were characterised by UV-Vis spectrometry, dynamic light scattering (DLS) and atomic force microscopy (AFM). The decrease in surface plasmon resonance (SPR) peak of the nanoparticles after dialysis indicates that quite a number of conduction electrons have gone into reaction, hence lowering of resonant frequency. The diameters of the nanoparticles as measured by DLS ranged from 102 nm in the 10 mM chloride AgNPs before dialysis to 892 nm in the 50 mM sample after dialysis, indicating aggregation over the dialysis period. On the other hand, particle sizes in terms of both height and diameter as measured by AFM decreased after dialysis. This could be explained that in spite of aggregation in solution, the AgNPs deposit as islands about 1 particle in height on the AFM substrate (Si wafer). Release of Ag(I) from the NPs was monitored by anodic stripping voltammetry at glassy carbon electrodes. Two interesting observations were made: (i) there is substantial (90 mM) Ag(I) present in the initial NP preparation and (ii) the concentration of Ag(I) after 73 h of dialysis remained easily detectable at about 4 µM irrespective of the concentration of chloride present. References 1 T.M. Benn, P.Westerhoff. Environ. Sci. Technol. 2008, 42, 4133-4139. 2 D.E Meyer, M.A. Curran, M.A. Gonzalez. J Nanopart Res. 2011, 13, 147-156. 3 A. Hebeish, M.H. El-Rafie, M.A. El-Sheikh, A.A. Saleem, M.E. El-Naggar. Intnal. Journ. of Macromolecules. 2014, 65, 509-515. 4 T. Maneerung, S. Tokura, R. Rujiavanit. Carbohydrate Polymers. 2008, 72, 43-51. 5 WHO Guidelines for Drinking-water quality. 2003. World Health Organisation, Geneva. 6 P.C. Lee, D. Meisel. J. Phys. Chem. 1982, 86, 3391-3395. Figure 1

Investigation of Selected Organic Compounds Influence on Water Quality Along the Olifants River in South Africa

Water is a crucial natural resource, indispensable to food production, life, the environment, power generation, industry, sanitation and hygiene. Organochlorine Pesticides (OCPs) in the environment are not wanted due to their negative effects on human beings and animals. As a result, there is a need to continuously monitor their presence in the environment. In this study, surface water samples were collected once a month during the dry season and during wet season from selected five points along the Olifants river in South Africa and stored at a temperature of ≤ 5°C before analysis. The OCPs were extracted with dichloromethane (DCM) using the Liquid-Liquid Extraction (LLE) method. After undertaking the sample through the clean-up process, the crude extracts obtained were put into the column chromatography and eluted with hexane and about 1.5 μL of the purified extracts were analysed by the Gas Chromatographic-Mass Spectrophotometer (GC/MS). The percentage recoveries, varied from 32-116% for p,p’-DDT and 4,4'-DDD respectively in triply spiked water samples. The standard deviation for most of the compounds is less than ± 0.04, with the exclusion of Heptachlor (± 0.14). The seasonal variability of OCPs show that during the dry season, the Olifants River is mostly polluted at the Oxford site with (BHC-beta, Aldrin, Heptachlor-epoxide, Endosulfan-alpha and Endrin), at the Ga-Selati site with (Heptachlor-epoxide and Endrin) and at the Wolvekrans site with (Endosulfan-alpha). The summer season data show that most pollution happen at the Ga-selati site with BHC-beta and at the Waterval site with (Heptachlor and BHC-gamma) respectively. The OCPs that reached the river catchment were significantly above the WHO drinking water quality guidelines and its cause for concern for those who are exposed or use it.

Health risk assessment of trace elements in drinking water from Najran City, southwestern Saudi Arabia

The concentrations of 16 trace elements (Ag, Al, As, B, Ba, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Se, Ti, U, and Zn) in drinking water from Najran City, Saudi Arabia, were determined by inductively coupled plasma-mass spectrometry (ICP-MS) and compared with local, regional, and international guidelines. Water samples from 22 water treatment plants and 13 commercial bottled water brands were analyzed. Except for B and U, the trace element concentrations were below the permitted limits defined in SASO, GSO, and WHO drinking water quality guidelines. The B concentrations in three brands of bottled water were 533.19, 602.29, and 1471.96 μg/L, which were all higher than the GSO and SASO limit (500 μg/L). The U concentrations were higher than the SASO limits for drinking water in two samples; one in treatment plant (2.39 μg/L) and another in foreign bottled water (2.17 μg/L). The median As, Ba, Cu, Ni, U, and Zn concentrations were statistically significantly higher in the treatment plant water samples than those in the bottled water samples, and conversely, the B concentrations were higher in the bottled water samples. The Cd, Hg, and Ti concentrations were below the detection limits of ICP-MS in all of the water samples. Apart from few exceptions, trace element concentrations in drinking water of Najran City were all within limits permitted in the national, regional, and international drinking water quality guideline values.

Fluoride in Drinking-water

Fluoride is known to occur at elevated concentrations in a number of parts of the world where it can be a significant cause of disease. The primary focus of Fluoride in Drinking Water is the prevention of adverse health effects from excessive levels of fluoride in drinking water. The book fills the urgent need, identified for updating the WHO Guidelines for Drinking-water Quality, for information on the occurrence of fluoride, its health effects, ways of reducing excess levels and methods for analysis of fluoride in water. The draft document, produced by a working group of experts convened to consider protection from fluoride and its control, was issued for extensive review and consultation. The resultant book, which incorporates the comments received, was further peer review by experts in developed and developing countries. It is aimed at a wide range of individuals, including health workers and sanitary engineers who may require a broad introduction to the subject with more detailed guidance in some specific areas. Fluoride in Drinking-water will be an invaluable reference source for all those concerned with the management of drinking-water containing fluoride and the health effects arising from its consumption, including water sector managers and practitioners as well as health sector staff at policy and implementation levels. It will also be of interest to researchers, students, and development workers and consultants. Contents Introduction Environmental occurrence, geochemistry and exposure Human health effects Guidelines and standards Removal of excessive fluoride Analytical methods Country data on dental and skeletal fluorosis associated with exposure to fluoride through drinking water Appendix: Indices of severity of dental fluorosis

Trace Elements as Indicators of Quality of Drinking Water in Offa Metropolis, Kwara State, Nigeria

This study involved the determination of trace elements in drinking water in Offa Metropolis. Drinking water samples were collected from tap, well, borehole, stream and sachet water and analysed for Cr, Co, Cu, Fe, Mg and Mn using Atomic Absorption Spectrophotometer. The results obtained show the concentration ranges of the metals in the samples as follows: Cr (0.01 - 0.27)mgL-1, Co (0.000 – 0.018) mgL-1, Cu (0.001 – 0.023) mgL-1, Fe (0.025 – 0.13) mgL-1, Mg (0.007 – 0.082) mgL-1 and Mn (0.002 – 0.009) mgL-1. In conclusion these concentrations are within the permissible limit of the WHO drinking water quality guidelines except chromium with twenty-one samples above the WHO threshold limit and four samples within the limit.Keywords: Offa metropolis, Trace elements, Water quality, Kwara State, Drinking water.

From international developments to local practice: Germany's evaluation and dialogue process towards Water Safety Plan implementation

The third edition of the WHO Guidelines for Drinking-water Quality establishes a ‘Framework for Safe Drinking-water’ that promotes a risk assessment and risk management approach called Water Safety Plan (WSP). In Germany, the discussion on the WSP approach started with significant scepticism by various stakeholders questioning its added value in light of the high quality and service level of water supply. In response, the Federal Ministry of Health, the Federal Environment Agency and the DVGW Association for Gas and Water jointly took the leadership for initiating a sectoral dialogue process involving water suppliers and local public health offices, including a series of WSP pilot projects to evaluate WSP feasibility, benefits and expected challenges for scaling-up. As the regulatory system in Germany makes explicit reference to ‘generally acknowledged codes of good practice’ the paper also examines how far the suite of established DVGW technical and managerial standards already supports WSP implementation. The evaluation process confirmed an added value of the WSP approach under Germany's national conditions, clearly providing an impetus for safeguarding a high quality and service level of drinking-water supply. Various activities to support scale-up implementation of a WSP-type approach have been initiated, including the preparation of step-by-step guidance in German (i.e. DVGW Guidelines W 1001), information campaigns to broadly raise awareness amongst all stakeholders in water supply, and capacity building initiatives.

Emerging resources to support water safety planning approaches

Since the introduction of the WSP approach in the 3rd edition of the WHO Guidelines for Drinking-water Quality in 2004, there has been widespread progress in WSP implementation. This paper discusses a number of resources that are currently being initiated to facilitate continued support for water safety planning. Furthermore, the concept of sanitation safety plans is being introduced.

Conclusion on the peer review of the pesticide risk assessment of the active substance acetochlor

Conclusion on the peer review of the pesticide risk assessment of the active substance acetochlor

Water- and wastewater-related disease and infection risks: what is an appropriate value for the maximum tolerable additional burden of disease?

The maximum additional burden of water- and wastewater-related disease of 10-6 disability-adjusted life year (DALY) loss per person per year (pppy), used in the WHO Drinking-water Quality Guidelines and the WHO Guidelines for Wastewater Use in Agriculture, is based on US EPA'S acceptance of a 70-year lifetime waterborne cancer risk of 10(-5) per person, equivalent to an annual risk of 1.4x10(-7) per person which is four orders of magnitude lower than the actual all-cancer incidence in the USA in 2009 of 1.8x10(-3) pppy. A maximum additional burden of 10(-4) DALY loss pppy would reduce this risk to a more cost-effective, but still low, risk of 1.4x10(-5) pppy. It would increase the DALY loss pppy in low- and middle-income countries due to diarrhoeal diseases from the current level of 0.0119 pppy to 0.0120 pppy, and that due to ascariasis from 0.0026 pppy to 0.0027 pppy, but neither increase is of public-health significance. It is therefore recommended that the maximum additional burden of disease from these activities be increased to a DALY loss of 10(-4) pppy as this provides an adequate margin of public-health safety in relation to waterborne-cancer deaths, diarrhoeal disease and ascariasis in all countries.

Benzene-Induced Hematopoietic Neoplasms Including Myeloid Leukemia in Trp53-Deficient C57BL/6 and C3H/He Mice

This research focused on three major questions regarding benzene-induced hematopoietic neoplasms (HPNs). First, why are HPNs induced equivocally and at only threshold level with low-dose benzene exposure despite the significant genotoxicity of benzene even at low doses both in experiments and in epidemiology? Second, why is there no linear increase in incidence at high-dose exposure despite a lower acute toxicity (LD(50) > 1000 mg/kg body weight; WHO, 2003, Benzene in drinking-water. Background document for development of WHO Guidelines for Drinking-Water Quality)? Third, why are particular acute myeloid leukemias (AMLs) not commonly observed in mice, although AMLs are frequently observed in human cases of occupational exposure to benzene? In this study, we hypothesized that the threshold-like equivocal induction of HPNs at low-dose benzene exposure is based on DNA repair potential in wild-type mice and that the limited increase in HPNs at a high-dose exposure is due to excessive apoptosis in wild-type mice. To determine whether Trp53 deficiency satisfies the above hypotheses by eliminating or reducing DNA repair and by allowing cells to escape apoptosis, we evaluated the incidence of benzene-induced HPNs in Trp53-deficient C57BL/6 mice with specific regard to AMLs. We also used C3H/He mice, AML prone, with Trp53 deficiency to explore whether a higher incidence of AMLs on benzene exposure might explain the above human-murine differences. As a result, heterozygous Trp53-deficient mice of both strains showed a nonthreshold response of the incidence of HPNs at the lower dose, whereas both strains showed an increasing HPN incidence up to 100% with increasing benzene exposure dose, including AMLs, that developed 38% of heterozygous Trp53-deficient C3H/He mice compared to only 9% of wild-type mice exposed to the high dose. The detection of AMLs in heterozygous Trp53-deficient mice, even in the C57BL/6 strain, implies that benzene may be a potent inducer of AMLs also in mice with some strain differences.