World Health Organization Water Quality Research Articles

Physicochemical and microbiological assessment of multi‐village drinking water source in diarrheal hotspot areas of north Shoa zone, Amhara region, Ethiopia

AbstractQuality water is essential to people's health and social and economic well‐being. Evaluation of the quality of the water sources provides benchmark data on quality status and insights into the development of further protective measures. A laboratory‐based cross‐sectional study design was conducted in the diarrheal hotspot area of the North Shewa zone. The contamination risks of water sources were assessed using the World Health Organization (WHO) sanitary inspection checklist. A grab water sample was collected from 138 multi‐village drinking water sources according to WHO guidelines. The collected sample was processed for physicochemical and microbiological analysis. Data were recorded and analyzed using SPSS version 25 software. The inspection survey indicated there was no proper handling of the water sources. The water temperature range was between 7 and 32°C, while the turbidity values ranged from 1.8 to 6 NTU. Electrical conductivity, pH, and total dissolved solutes were 100% within the acceptable limits of WHO and the Ethiopian Ministry of Health (EMoH) water quality guidelines. However, only (77/138, 55.79%) and (101/138, 73.29%) drinking water sources were within the acceptable range of temperature and turbidity, respectively. The mean bacteriological counts in multi‐village drinking water sources were a mean value of 72.14, 29.78, 21.09, and 15.64 for TMC, TCC, FC, and FSC, respectively. A total of (19/138, 13.8%) drinking water samples were positive for total coliform (Tc) and/or fecal coliforms (Fc). The remaining (119/138, 86.2%) water samples were bacteriologically potable. The physicochemical quality of the drinking water sources was consistent with WHO and national water quality standards, except that turbidity exceeded the acceptable range. The results also showed that some water sources were contaminated with fecal and total coliform, which was supported by an inspection survey in which most water sources were poorly protected. These research findings can serve as a valuable evidence base for informing policy decisions and guiding practical interventions aimed at ensuring access to safe drinking water in diarrheal hotspot areas.

Assessment of suitability of drinking water from the springs in Urban slums of Kampala

Any water source used for domestic purposes should meet World Health Organization water quality standards. In most slums of developing nations, water sources such as springs are critical to the residents. Although spring water is often considered fit for domestic use, poor sanitation practices in slums lead to faecal contamination of spring. The objectives of this study were to assess the faecal contamination risk factors and the water quality from the identified springs in Bwaise, Kampala in the dry and rainy seasons. Parameters that were considered in this study were: pH, Electrical conductivity, apparent colour, turbidity, hardness, Chloride, Nitrate, total coliform and E-coli. The cross-sectional sanitary risk assessment for all springs revealed faecal contamination risks. The physiochemical parameters were within the allowable limits of World Health Organization standards for drinking water in all seasons. E-coli values were between 1.35 -13.75Cfu/ 100ml in all seasons. Both total coliform and E-coli were above the permissible limit of o Cfu/100ml in all seasons. When the water samples were analyzed basing WQI, the indices revealed excellent water during the dry season and good water during the wet season. The index values were between 40.09 to 49.34 in the dry season and 54.24 to 74.17 in the wet season. Therefore, treatment or boiling before drinking should be encouraged in the community. Also, proper solid waste management and pit latrine construction strategies should be used in the area

Physiochemical and Bacteriological Analysis of Groundwater at Dutse, Bwari Area Council, FCT, Abuja

This study characterizes groundwater's physicochemical parameters and bacteriological analysis in Bwari, FCT, Nigeria. Nine boreholes were randomly selected for sampling. Sample locations include Dutse Sokali, Dutse Baupma, Dutse Jabu, Kogo, Bwari, Sabon Gari Bwari, Dimas Isuwa Street, Bwari, Dutse Alhaji, Tasha Bwari and F01 Kubwa Bwari. The parameters studied were pH, Electrical Conductivity, Fluorine, Nitrate, Total Dissolved Solids, Chloride, Sulphate, Biocarbonate and bacteriological assessment. In addition, a comparative analysis was done using the World Health Organization water quality standard (WHO). The comparative analysis shines a light on the groundwater contamination in the area.

Analysis of variation of water quality parameters along treatment processes in OPA waterworks, ILE-IFE, Nigeria

This study was conducted to assess the variation of water quality parameters along the treatment processes of Opa Waterworks at Obafemi Awolowo University, Ile – Ife, Nigeria. This was to ascertain how chemical and physical parameters vary along the treatment plant visits while at the same time ensuring that the influent and effluent conforms to water quality standards set by the World Health Organization.Determination of physicochemical parameters; pH, temperature, conductivity, turbidity, nitrate and chloride was done by  using standard methods while a colorimetric,  and atomic absorption spectrometry methods were used for the selected heavy metals; cadmium, zinc and copper.It was observed that for the influent, the concentration of lead was 9.44 mg/l, nitrate 0.25 mg/l, chloride 18.27 mg/l, sulphate 4.29 mg/l, copper 4.55 mg/l, zinc 0.07 mg/l and cadmium 1.10 mg/l. For the effluent, the concentration of nitrate was 0.22 mg/l, chloride 16.01 mg/l and sulphate 4.29 mg/l while that of lead, copper, zinc and cadmium was 0.00 mg/l. The overall results show that the concentrations of the water quality parameters tested conform to the World Health Organization water quality standards at the effluent points of the treatment plant. Â

Decontamination of SARS-CoV-2 from cold-chain food packaging provides no marginal benefit in risk reduction to food workers.

Countries continue to debate the need for decontamination of cold-chain food packaging to reduce possible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) fomite transmission among frontline workers. While laboratory-based studies demonstrate persistence of SARS-CoV-2 on surfaces, the likelihood of fomite-mediated transmission under real-life conditions is uncertain. Using a quantitative microbial risk assessment model of a frozen food packaging facility, we simulated 1) SARS-CoV-2 fomite-mediated infection risks following worker exposure to contaminated plastic packaging; and 2) reductions in these risks from masking, handwashing, and vaccination. In a frozen food facility without interventions, SARS-CoV-2 infection risk to a susceptible worker from contact with contaminated packaging was 1.5 × 10−3 per 1h-period (5th – 95th percentile: 9.2 × 10−6, 1.2 × 10−2). Standard food industry infection control interventions, handwashing and masking, reduced risk (99.4%) to 8.5 × 10−6 risk per 1h-period (5th – 95th percentile: 2.8 × 10−8, 6.6 × 10−5). Vaccination of the susceptible worker (two doses Pfizer/Moderna, vaccine effectiveness: 86–99%) with handwashing and masking reduced risk to 5.2 × 10−7 risk per 1h-period (5th – 95th percentile: 1.8 × 10−9, 5.4 × 10−6). Simulating increased transmissibility of current and future variants (Delta, Omicron), (2-, 10-fold viral shedding) among a fully vaccinated workforce, handwashing and masking continued to mitigate risk (1.4 × 10−6 - 8.8 × 10−6 risk per 1h-period). Additional decontamination of frozen food plastic packaging reduced infection risks to 1.2 × 10−8 risk per 1h-period (5th – 95th percentile: 1.9 × 10−11, 9.5 × 10−8). Given that standard infection control interventions reduced risks well below 1 × 10−4 (World Health Organization water quality risk thresholds), additional packaging decontamination suggest no marginal benefit in risk reduction. Consequences of this decontamination may include increased chemical exposures to workers, food quality and hazard risks to consumers, and unnecessary added costs to governments and the global food industry.

Drinking Water Quality Mapping Using Water Quality Index and Geospatial Analysis in Primary Schools of Pakistan

Primary school children in the developing world often lack potable water, which may result in a high burden of water-related diseases and poor school performance. The present study aimed to characterize the drinking water quality in primary schools of Pakistan. We used a multistage random-sampling method to select 425 primary schools from selected districts of Sindh province. Standard methods were used to characterize water quality. The results were compared with maximum acceptable values recommended by the Pakistani National Environmental Quality Standards (Pak NEQS) and the World Health Organization (WHO) drinking water quality standards. Groundwater (62%) and surface water (38%) were identified as two major drinking water sources in the selected schools with varying levels of water quality. Among all parameters, dissolved oxygen (DO), pH, and nitrate remained within WHO and Pak NEQS water quality standard limit, while total dissolved solids (TDS) (33%), electrical conductivity (EC) (46%), chloride (34%), turbidity (27%), and hardness (11%) samples exceeded standard limits. All dissolved salts had moderate to strong positive correlations with TDS and EC values. Based on a water quality index (WQI), 74% of primary schools had access to excellent or good quality drinking water compared to 26% of schools that had access to either poor, very poor or unsuitable drinking water. Among all three regions, more schools from South Sindh had either poor, very poor or unsuitable drinking water (33%) compared to the Central (25%) and North zones (15%). Hence, water from these locations is unfit for human consumption and these schools need better water quality management plans to stop the spread of water-related diseases in primary school children.

Bacteriological Contamination of Drinking Water Supply from Protected Water Sources to Point of Use and Water Handling Practices among Beneficiary Households of Boloso Sore Woreda, Wolaita Zone, Ethiopia.

The quality of drinking water is a powerful environmental determinant of health. Water becomes contaminated with faecal material due to inadequate protection of the source, unhygienic practices of the community at the source, and poor household handling practices. The objective of this study was to assess the level of bacteriological contamination of drinking water supply from protected water sources to point of use and water handling practices among beneficiary households of Boloso Sore woreda, Wolaita zone, Ethiopia. A cross-sectional survey and bacteriological analysis of water were conducted in January 2019. The study included 545 households for water handling practices, and 75 samples from stored water from households and eighteen water sources were included for faecal coliform test. Data were analyzed using SPSS v21.0. Descriptive and logistic regression statistical models were used. Sixty percent of shallow wells, 60% of protected hand-dug wells, and 25% of protected on-spot springs were found positive for faecal coliform. In general, 44% of water source samples and 91% of household water samples were positive for faecal coliform. In general, 38% of households were practicing unsafe water handling practices. High school and above level of education (AOR = 3.37, 95% CI: 1.03, 11.57), getting higher monthly income (AOR = 2.37, 95%CI: 1.96, 5.85), households with small family size (AOR = 1.81, 95% CI: 1.15, 2.83), frequency of water collection twice a day (AOR = 2.88, 95% CI:1.56, 5.33), and presence of water payments (AOR = 0.42, 95% CI: 0.24, 0.72) were significantly associated with water handling practice. Unsafe water handling was a common practice in the study area, and water sources and household water storage were not free of faecal coliform, indicating noncompliance with the World Health Organization water quality guideline. Hence, capacity building is mandatory for the protection and management of water sources and safe water handling practices in the household and community.

Design of Low Energy Integrated Membranes Units for Production of Highly Purified Water

Some industries like medical, pharmaceuticals, cosmetics, chemical manufacturing need a special quality of treated water which is called Purified water. Integrated membrane system was designed and developed to produce Purified water grades to serve these industries. A simple engineering design for water filtration through membrane systems was scanned; beginning from carbon filters, followed by different kinds of membranes like microfiltration, ultrafiltration, nanofiltration and reverse osmosis membrane. These units were developed according to membranes type and the produced water quality before and after each unit. The Produced water and its quality control tests were compared with the World Health Organization water quality standard. The produced water from the integrated membrane system has TDS reached 0.95 mg/L, which matched with the World Health Organization water quality standard.

Assessment of drinking water quality and rural household water treatment in Balaka District, Malawi

Access to drinking water from unsafe sources is widespread amongst communities in rural areas such as Balaka District in Malawi. This situation puts many individuals and communities at risk of waterborne diseases despite some households adopting household water treatment to improve the quality of the water. However, there still remains data gaps regarding the quality of drinking water from such sources and the household water treatment methods used to improve public health. This study was, therefore, conducted to help bridge the knowledge gap by evaluating drinking water quality and adoption rate of household water treatment and storage (HWTS) practices in Nkaya, Balaka District. Water samples were collected from eleven systematically selected sites and analyzed for physico-chemical and microbiological parameters: pH, TDS, electrical conductivity (EC), turbidity, F−, Cl−, NO3−, Na, K, Fe, Faecal Coliform (FC) and Faecal Streptococcus (FS) bacteria using standard methods. The mean results were compared to the World Health Organization (WHO) and Malawi Bureau of Standards (MBS) (MS 733:2005) to ascertain the water quality for drinking purposes. A total of 204 randomly selected households were interviewed to determine their access to drinking water, water quality perception and HWTS among others. The majority of households (72%, n = 83) in Njerenje accessed water from shallow wells and rivers whilst in Phimbi boreholes were commonly used. Several households (>95%, n = 204) were observed to be practicing HWST techniques by boiling or chlorination and water storage in closed containers. The levels of pH (7.10–7.64), F− (0.89–1.46 mg/L), Cl− (5.45–89.84 mg/L), NO3− (0–0.16 mg/L), Na (20–490 mg/L), K (2.40–14 mg/L) and Fe (0.10–0.40 mg/L) for most sites were within the standard limits. The EC (358–2220 μS/cm), turbidity (0.54–14.60 NTU), FC (0–56 cfu/100 mL) and FS (0–120 cfu/100 mL) - mainly in shallow wells, were found to be above the WHO and MBS water quality specifications. The majority of the water samples (73%, n = 11) were classified as of “Intermediate risk” (FC 11–100 cfu/100 mL), hence not suitable for human consumption without prior treatment. This calls for large scale adoption of HWTS and continued monitoring of the water sources used in the study areas.

Application of magnesite–bentonite clay composite as an alternative technology for removal of arsenic from industrial effluents

This study evaluated the feasibility of integrating amorphous magnesite and bentonite clay (composite) as an alternative technology for removing arsenic from industrial effluents. The removal of arsenic from industrial effluents by using magnesite–bentonite clay composite was carried out in batch mode. The effects of equilibration time, adsorbent dosage, adsorbate concentration, and pH on removal of arsenic were investigated. The experiments demonstrated that ≈100% arsenic removal is optimum at 30 minutes of agitation, 2 g of adsorbent dosage (2 g: 100 mL, S/L ratio), and 20 mg L−1 of arsenic concentration. The adsorption data fitted well to both Langmuir and Freundlich adsorption models, hence proving monolayer and multilayer adsorption. The kinetic studies revealed that the data fitted better to a pseudo-second-order reaction than to a pseudo-first-order reaction, hence proving chemisorption. At optimized conditions, the composite was able to remove arsenic to below World Health Organization water quality guidelines, hence depicting that the composite is effective and efficient in removing arsenic from contaminated water. Based on that, this comparative study proves that the composite is a promising adsorbent with high adsorption capacity for arsenic and can be a suitable substitute for the conventional treatment methods.

Occurrence and infection risk of waterborne pathogens in Wanzhou watershed of the Three Gorges Reservoir, China

The Three Gorges Reservoir (TGR), formed by China's Yangtze Three Gorges Project, is the largest lake in the world, but there is too little information available about fecal contamination and waterborne pathogen impacts on this aquatic ecosystem. During two successive 1-year study periods (July 2009 to July 2011), the water quality in Wanzhou watershed of the TGR was tested with regard to the presence of fecal indicators and pathogens. According to Chinese and World Health Organization water quality standards, water quality in the mainstream was good but poor in backwater areas. Salmonella, Enterohemorrhagic Escherichia coli (EHEC), Giardia and Cryptosporidium were detected in the watershed. Prevalence and concentrations of the pathogens in the mainstream were lower than those in backwater areas. The estimated risk of infection with Salmonella, EHEC, Cryptosporidium, and Giardia per exposure event ranged from 2.9 × 10−7 to 1.68 × 10−5, 7.04 × 10−10 to 2.36 × 10−7, 5.39 × 10−6 to 1.25 × 10−4 and 0 to 1.2 × 10−3, respectively, for occupational divers and recreational swimmers exposed to the waters. The estimated risk of infection at exposure to the 95% upper confidence limit concentrations of Salmonella, Cryptosporidium and Giardia may be up to 2.62 × 10−5, 2.55 × 10−4 and 2.86 × 10−3, respectively. This study provides useful information for the residents, health care workers and managers to improve the safety of surface water and reduce the risk of fecal contamination in the TGR.

Chemical Properties of Drinking Water of Renigunta Near Tirupati, Andhra Pradesh, India and its Impact on Human Health

This paper is an attempt to assess the effect of drinking water quality on health of the people living in Renigunta, an industrial area near Tirupati, Andhra Pradesh, India. Drinking water samples were collected from 40 different locations of Renigunta and analyzed for physicochemical parameters such as pH, hard ness, alkalinity, calcium, magnesium, iron, nitrates, chlorides, sulphates, electrical conductivity, total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), dissolved oxygen (DO), chemical oxygen demand (COD) and bio chemical oxygen demand (BOD). The found values of physicochemical parameters were compared with the World Health Organization water quality standards. Study of all these characteristics and correlation studies indicate that in some of the studied areas water was polluted and not suitable for drinking purpose. The drinking water of the area needs some degree of treatment before consumption and prevention steps to be taken from contamination.

Accounting for water quality in monitoring access to safe drinking-water as part of the Millennium Development Goals: lessons from five countries

To determine how data on water source quality affect assessments of progress towards the 2015 Millennium Development Goal (MDG) target on access to safe drinking-water. Data from five countries on whether drinking-water sources complied with World Health Organization water quality guidelines on contamination with thermotolerant coliform bacteria, arsenic, fluoride and nitrates in 2004 and 2005 were obtained from the Rapid Assessment of Drinking-Water Quality project. These data were used to adjust estimates of the proportion of the population with access to safe drinking-water at the MDG baseline in 1990 and in 2008 made by the Joint Monitoring Programme for Water Supply and Sanitation, which classified all improved sources as safe. Taking account of data on water source quality resulted in substantially lower estimates of the percentage of the population with access to safe drinking-water in 2008 in four of the five study countries: the absolute reduction was 11% in Ethiopia, 16% in Nicaragua, 15% in Nigeria and 7% in Tajikistan. There was only a slight reduction in Jordan. Microbial contamination was more common than chemical contamination. The criterion used by the MDG indicator to determine whether a water source is safe can lead to substantial overestimates of the population with access to safe drinking-water and, consequently, also overestimates the progress made towards the 2015 MDG target. Monitoring drinking-water supplies by recording both access to water sources and their safety would be a substantial improvement.

Assessment of potable water quality including organic, inorganic, and trace metal concentrations

The quality of drinking water (tap, ground, and spring) in Toyama Prefecture, Japan was assessed by studying quality indicators including major ions, total carbon, and trace metal levels. The physicochemical properties of the water tested were different depending on the water source. Major ion concentrations (Ca(2+), K(+), Si(4+), Mg(2+), Na(+), SO(4)(2-), HCO(3)(-), NO(3)(-), and Cl(-)) were determined by ion chromatography, and the results were used to generate Stiff diagrams in order to visually identify different water masses. Major ion concentrations were higher in ground water than in spring and tap water. The relationship between alkaline metals (Na(+) and K(+)), alkaline-earth metals (Ca(2+) and Mg(2+)), and HCO(3)(-) showed little difference between deep and shallow ground water. Toyama ground, spring, and tap water were all the same type of water mass, called Ca-HCO(3). The calculated total dissolved solid values were below 300 mg/L for all water sources and met World Health Organization (WHO) water quality guidelines. Trace levels of As, Cd, Cr, Co, Cu, Fe, Pb, Mn, Mo, Ni, V, Zn, Sr, and Hg were detected in ground, spring, and tap water sources using inductively coupled plasma atomic emission spectrometry, and their levels were below WHO and Japanese water quality standard limits. Volatile organic carbon compounds were quantified by headspace gas chromatography-mass spectrometry, and the measured concentrations met WHO and Japanese water quality guidelines. Total trihalomethanes (THMs) were the major contaminant detected in all natural drinking water sources, but the concentration was highest in tap water (37.27 ± 0.05 μg/L). Notably, THMs concentrations reached up to 1.1 ± 0.05 μg/L in deep ground water. The proposed model gives an accurate description of the organic, inorganic, and trace heavy metal indicators studied here and may be used in natural clean water quality management.