Drinking Water Samples Research Articles

The new map of Argentine population exposed to arsenic in drinking water

ABSTRACT This study aims to evaluate the population exposed to arsenic in Argentina, proposing a key risk indicator. By employing specific criteria selection, a systematic search of the published evidence on arsenic content in drinking water samples at the provincial level was carried out. Considering the limit recommended by the WHO – 10 μg/L – representativeness of evidence was calculated, as well as the percentage of exposed population (PEP) to high levels of arsenic. For this research, 61 useful publications were found and included in the analysis. They provide relevant data for 50% of the provinces, which represent 70% of the national population. The use of the PEP index, to denote the ‘percentage of population exposed’ to high arsenic, is proposed as a summary variable, to homogenize the information in the country, and in this way give it comparative value. Information has been systematized and variables identified that may be useful for analysis in eco-epidemiological studies, detailing the current situation of publications of arsenic in drinking water in Argentina.

Enteric Pathogens in Humans, Domesticated Animals, and Drinking Water in a Low-Income Urban Area of Nairobi, Kenya.

To explore the sources of and associated risks with drinking water contamination in low-income, densely populated urban areas, we collected human feces, domesticated animal feces, and source and stored drinking water samples in Nairobi, Kenya in 2019; and analyzed them using microbial source tracking (MST) and enteric pathogen TaqMan Array Cards (TACs). We established host-pathogen relationships in this setting, including detecting Shigella and Norovirus─which are typically associated with humans─in dog feces. We evaluated stored and source drinking water quality using indicator Escherichia coli (E. coli), MST markers, and TACs, detecting pathogen targets in drinking water that were also detected in specific animal feces. This work highlights the need for further evaluation of host-pathogen relationships and the directionality of pathogen transmission to prevent the disease burden associated with unsafe drinking water and domestic animal ownership.

Investigation of the physicochemical parameters of drinking water in Herat province and its comparison with World Health Organization standards

AbstractThe physical, chemical, and microbial parameters of drinking water are the basis for judging if it is potable. Undesirable changes in these parameters can threaten the users’ health. Therefore, the present study aimed to evaluate the physicochemical qualities of drinking water in Herat Province and compare them with the WHO standards. 45 drinking water samples were collected from Herat Province to undergo physicochemical tests. This study was conducted in 2023. The mean values measured for parameters such as temperature, turbidity, electrical conductivity (EC), pH, total dissolved solids (TDS), fluoride, nitrate, calcium, magnesium, and total hardness (TH) were 26.3℃, 0.93 NTU, 1328 μS/cm /cm, 7.32, 576.8, 0.26, 12.014, 6.8, 11.25, and 58.33 mg/L, respectively. The turbidity, TDS, and EC of some samples were higher than the highest desirable limit (HDL) but lower than the Maximum allowable limit (MAL). Also, there is a shortage of fluoride in samples. The Water Quality Index (WQI) shows that the quality of drinking water in Herat Province is classified as Poor.

Мікроелементний склад питної води при централізованому водопостачанні промислових міст Дніпропетровської області

The purpose. Ecological and hygienic assessment of the quality of drinking water at the centralized water supply of industrial cities of the Dnipropetrovsk region by the content of trace elements from the group of heavy metals. Object and research methods. The analysis of the content of trace elements from the group of heavy metals in the drinking water of industrial cities of the Dnipropetrovsk region - Dnipro, Kryvyi Rih, Kamianske over a 5-year period was carried out. The evaluation of the obtained data was carried out in accordance with the requirements of the current legislation on the safety and quality of drinking water in accordance with SSRN 2.2.4-171-10, international recommendations and data from the scientific literature. Results. It has been established that in the Dnipropetrovs'k region over the 5-year study period, the percentage of non-standard drinking water samples for sanitary and chemical parameters ranged from 24.4-30.6% from centralized water supply systems, and 14.5-18.4% from water supply networks. The average long-term concentrations of metals in the drinking water of the studied cities ranged from 0.0001 mg/l for mercury to 0.19 mg/l for aluminum, which meets the MAC requirements, but the maximum values of the content of individual metals in all industrial cities exceeded the hygienic regulations, most pronounced for iron, which reached 60%. At the same time, the proportion of samples exceeding the hygienic standard in some years of the study was 5-12%. In the dynamics of the study, a gradual decrease of 14.2-54.5% in the concentration of lead in drinking water in all industrial and control cities was noted (p<0.05; R2= 0.51-0.78). A similar trend is also characteristic of the aluminum content in drinking water in Kryvyi Rih - a 2.5-fold decrease (p<0.001; R2=0.79) during the study period. At the same time, a significant increase in the content of a number of trace elements from the group of biotic and abiotic heavy metals was found in Kamianske, in particular copper and zinc - by 2.0-2.4 times (p<0.01; R2= 0.72-0.77), mercury and arsenic - by 1.3-1.9 times (p<0.01; R2= 0.87-0.92). The dynamics of concentrations of other heavy metals in the drinking water of the studied cities was unreliable. The sum of the ratio of the concentrations of trace elements from the group of heavy metals belonging to hazard classes I and II according to the sanitary and toxicological limiting sign of harmfulness ranges from 1.1 to 1.9, i.e. the simultaneous presence of these metals in the drinking water of industrial cities exceeds the safe level regulated by SSRN 2.2.4-171-10. Conclusions. The results of the conducted research indicate the urgency of the problem of ensuring the quality and safety of drinking water intended for human consumption and the need for further improvement of water treatment and control methods at all levels. Keywords. Trace elements, heavy metals, drinking water, content, pollution, impact, public health.

Risk assessment of uranium in water sources near coal mines and in human organs of Shahdol District, Madhya Pradesh, using biokinetic modelling.

This study concentrated on determining the levels of uranium present in drinking water samples obtained from various locations throughout the Shahdol district in Madhya Pradesh, India. In this assessment a LED fluorimeter Quantalase (LF-2a) was utilized. Uranium, being a radioactive substance, can be hazardous to health when consumed in significant quantities over extended durations. The study found that the average uranium concentration was 167.91µg/L. 82% of samples exceeded recommended limits, emphasizing the essential aspect of this study. The study utilizes the age-specific biokinetic model developed by the International Commission on Radiological Protection to examine uranium distribution across various organs. Using dosimetric model, the study provides a comprehensive health risk analysis by assessing the chemical toxicity and the radiation dosages received by particular organs. Longitudinal studies on uranium distribution across different organs and tissues showed that the kidneys, liver, non-exchangeable bone volume, and soft tissues are the primary locations where uranium accumulates.

Extended-Spectrum Beta-Lactamase-Producing and Multidrug-Resistant Escherichia coli and Klebsiella spp. from the Human–Animal–Environment Interface on Cattle Farms in Burkina Faso

Extended-spectrum beta-lactamase (ESBL)-producing and multidrug-resistant Enterobacterales pose a major threat to both human and animal health. This study assessed the prevalence of ESBL-producing Escherichia coli (ESBL-Ec) and Klebsiella spp. (ESBL-K) on cattle farms in Ouagadougou, Burkina Faso, using a One Health approach. From May 2021 to September 2022, cattle faeces, farmers’ stools, their drinking water and farm soil samples were collected from semi-intensive and traditional farms. An ESBL-selective medium was used to obtain resistant isolates, which were further characterised using biochemical tests. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disc diffusion method. ESBL-Ec and/or ESBL-K were detected in 188 of 322 samples (58.0%). The prevalence of ESBL-Ec isolates was 42.2% (136/322) and that of ESBL-K isolates was 24.5% (79/322). Notably, 156 of the 188 ESBL isolates (83.0%) exhibited multidrug resistance. The highest resistance rates were observed against tetracycline and cotrimoxazole. Importantly, no isolates showed resistance to meropenem, which was used to test for carbapenem resistance. This study highlights the presence of ESBL-Ec and ESBL-K among the humans, animals and environment of the cattle farms. Good hygiene and biosafety practices are essential to limit the potential spread of multidrug-resistant bacteria between different interfaces on farms.

Simple, Specific, and Ultra‐Sensitive Arsenic Detection in Real Drinking Water Samples Using an Impedimetric Green Sensor with Dimercaprol‐Doped Solid Electrolyte

AbstractArsenic monitoring is of paramount importance due to its toxicity, which poses potential public health hazards. While numerous sensitive methods exist, many are unsuitable for on‐site, rapid, real‐time measurements, and their sensor preparation is often time‐consuming and intricate. Addressing this gap necessitates the development of an easy‐to‐use, rapid, and reasonably affordable arsenic detection device featuring an eco‐friendly sensor. For on‐site arsenic monitoring, the optimal solution involves creating a sensitive impedimetric electrochemical sensor that is real‐time, fast, low‐cost, simple to design and use, and portable. This study introduces an electrochemical impedimetric sensor with a patent‐pending, solid electrolyte based on gelatin enriched with dimercaprol. The results demonstrate the detection of phenylarsine oxide in real drinking water samples, achieving a detection limit of 0.02 ng/mL within the linear range of 0.05 ng/mL to 100 ng/mL in just 40 minutes, utilizing a simple method and easily accessible, inexpensive, biodegradable chemicals. The methodology yields a sensitive sensor with biodegradable potential, exerting a negligible impact on the environment and human health.

Human health risks assessment of toxic metals via water, food, and soil: A case study of Northern areas (Ghizer and Gilgit) of Pakistan

Health concerns have arisen worldwide as a result of contaminated food and water. This study was aimed to determine the levels of selected heavy metals i.e. cadmium (Cd), chromium (Cr), copper (Cu) manganese (Mn), and nickel (Ni) in various sources such as drinking water, vegetables, and soil in districts Ghizer and Gilgit, Pakistan. Human health risks were assessed using deterministic indices, a probabilistic approach, and multivariate analysis. The determinations were carried out by spectrophotometrically (AAS-700, Perkin Elmer, USA) following the standard procedures for heavy metal levels. The mean concentration was recorded as Cd 0.036 mg/L, Cr 0.076 mg/L, and Ni 0.394 mg/L, respectively. It revealed an exceeded level for Cd (0.03 mg/L) and Cr (0.07 mg/L) against the safe limits in drinking water of Gilgit and Ghizer. The highest hazard quotient (HQ) was recorded as Cd 3000, Cr 3863.33, Cu 21.7, Mn 45.71, and Ni 22.35 for children regarding the consumption of vegetables from district Ghizer. Whereas higher HQ values were recorded for adults regarding consumption of vegetables from district Gilgit. A hazard index (HI) indicates significant non-carcinogenic health risks (HI > 1) in Ghizer and Gilgit drinking water and vegetables. Gilgit soil HI values exceeded more than one due to dermal contact, while HI > 1 due to oral and dermal exposure in Ghizer. Furthermore, drinking water samples and vegetables from both districts showed cancer risk (CR) > 1 × 10–4. The cumulative lifetime cancer risk (CR) was observed as 88.61 and 65.61 for adults whereas 2. 98 and 0.38 for children pertaining to vegetable consumption from Ghizer and Gilgit. It was found that the lifetime cancer risk (LCR) for Ghizer was higher than that for Gilgit, based on soil dermal and oral contact. Monte Carlo Simulation revealed adverse health risks in children as compared to adults. As a result of exposure to toxic metals, drinking water and vegetable consumption have higher cancer-causing risks. Therefore, we recommend that both districts implement strict monitoring regulations for drinking water and vegetables.

Determining bad actors: A linear mixed effects model approach to elucidate behavioral toxicity of metal mixtures in drinking water

Mixtures of chemical contaminants can pose a significant health risk to humans and wildlife, even at levels considered safe for each individual chemical. There is a critical need to develop statistical methods to evaluate the drivers of toxic effects in chemical mixtures (i.e., bad actors) from exposure studies. Here, we develop a hierarchical modeling framework to disentangle the toxicity of complex metal mixtures from a screening study of 92 drinking well water samples containing multiple metal elements from Maine and New Hampshire, USA. In order to screen for neurodevelopmental impacts from exposure to these drinking water samples, we use a larval zebrafish (Danio rerio) behavioral assay. Zebrafish are an advantageous toxicological model organism due to combining the complexity of a vertebrate organism and higher-throughput exposure methods. We formulate a linear mixed modeling approach that captures intrinsic complexity in a common larval behavioral assay in order to improve its sensitivity and rigor and identify drivers of behavioral toxicity from the metal mixtures within the drinking water samples. Our analysis identifies lead (Pb), cadmium (Cd), nickel (Ni), copper (Cu), barium (Ba), and uranium (U) as metals that consistently impact larval locomotor activity, individually and across nine pairs of those metals. Our model also elucidates three distinct clusters of metal mixture components that drive behavioral effects: (Ba:Cu:U), (Ni:Pb:U), (Ba:Pb:U). Having identified a set of “bad-actor” metals from the water samples, we conduct exposure experiments for each individual metal (Pb, Cd, Ni, Cu, and Ba) at levels considered safe by the US Environmental Protection Agency drinking water regulatory limits and validate Pb, Ni, Cu, and Ba as behavioral toxicants at these concentrations. Collectively, our modeling approach estimates the impact of metal elements on a complex behavioral outcome in a statistically robust manner and establishes an approach to capture “bad actors” and key chemical interactions in a complex mixture.

Acriflavine-modified UIO-66 ratiometric fluorescent sensor for highly selective and fast detection of hypochlorite in water

Hypochlorite (ClO−) as a kind of highly toxic pollutant has garnered significant interest in detection methods, highlighting the pressing need to develop intelligent functional materials for the qualitative and quantitative analysis of ClO− in aqueous solutions. Herein, a ratiometric fluorescent sensor was prepared by the combination of acriflavine (Acr) and UIO-66 via a post-synthetic modification strategy. Acr/UIO-66 exhibited both high crystallinity typical of metal–organic frameworks and demonstrated good fluorescent and thermal stability. Additionally, Acr/UIO-66 functioned effectively as a dual-responsive fluorescent platform for detecting ClO− in domestic drinking and surface water samples. This material displayed high sensitivity, exceptional selectivity, and superior anti-interference capabilities, along with fast respond time (60 s), a wide pH range (4.0–7.0), high recoveries (94.46–118.00 %), a broad linear range (0–28 µmol L−1) and low detection limits (0.74 µmol L−1). This study broadened the potential applications of fluorescent metal–organic frameworks and presented a feasible solution for water quality monitoring.

Ion-chromatographic determination of common anions in drinking water in some regions of the Republic of Armenia

The present study investigated the anion composition of drinking water from various cities and villages in Armenia, including spring water and tap water samples. The simultaneous separation was achieved for fluoride, chloride, bromide, nitrite, nitrate, sulfate, and phosphate anions with the correlation coefficients >0.998. Validation of the method was carried out in accordance with the requirements of guidelines in terms of selectivity, specificity, system suitability, linearity, accuracy, precision, lower limits of detection and quantitation, robustness, and stability. The method was suitable for routine drinking water quality assessment in line with the national or World Health Organization (WHO) regulations. The validated method was further used to analyze drinking water samples from different regions of Armenia. The observed concentrations for the anions in drinking water complied with the WHO limits for drinking water with some exceptions. The test method can be submitted to quality control laboratories as a convenient and practical tool for routine analysis and monitoring studies.

The Presence of Heavy Metals in Drinking Water and Its Possible Impact on the Development of Type 1 Diabetes in Children

This study aimed to determine the relationship between the concentration of heavy metals in drinking water and the number of type 1 diabetes mellitus (T1DM) cases in two regions of Poland. The number of births in 2015-16 in Pomeranian Voivodeship was 50,461, while the number of new T1DM cases was 219. In Lublin Voivodeship, the number of births in the same period reached 39,381, and the number of new T1DM cases was 221. The incidence of T1DM, calculated per 100 live births, amounted to 0.43 and 0.56 in Pomeranian and Lublin. The statistical analysis of collected data proved that the number of new T1DM cases in Pomeranian Voivodeship is correlated to the concentrations of selenium (Se; p < 0.0001), lead (Pb; p < 0.00001), cadmium (Cd; p < 0.00001), zinc (Zn; p < 0.00001) and arsenic (As; p = 0.00001). In the case of Lublin Voivodeship, the number of new T1DM cases was correlated to the concentrations of Se (p = 0.0000001), Pb (p < 0.000001), Cd (p = 0.0000001) and Zn (p < 0.00001) in drinking water. No correlation was found between the number of new T1DM cases and arsenic concentration in the drinking water samples from Lublin Voivodeship. The results indicated that environmental exposure to specific heavy metals may contribute to the risk of T1DM, underscoring the need for stringent environmental controls and public health policies to mitigate these risks.

Residual Assessment of Emerging Pesticides in Aquatic Sinks of Lahore, Pakistan

In recent decades, the use of pesticides has become fundamental to agricultural growth. However, the persistent and toxic nature of pesticides has led to significant concerns regarding their ecological and human health consequences. Therefore, for a better understanding of pesticide contamination and its potential risks, here we assessed the levels of five emerging pesticides—acetochlor, imidacloprid, MCPA, atrazine, and allethrin—in soil samples from ponds used for irrigation and in drinking water samples from nearby areas in Lahore, Pakistan. Our findings revealed that 100% of the samples were contaminated, posing substantial ecological and human health risks. Based on the toxic units (TUsum), all the soil samples showed higher toxic pressure, exceeding acute and chronic toxicity thresholds for earthworms, while 100% of water samples posed chronic toxicity risks to crustaceans and 10% to algae. Pollution index (PI) analysis further classified 100% of the soil samples and 10% of the water samples as highly polluted. These findings show high-pesticide residues in both soil and water and highlight immediate risk assessment and mitigation measures to protect non-target organisms. This preliminary information can be used to adopt risk assessment monitoring programmes and help higher authorities in making policies and guidelines to mitigate the escalating risk for ecology and humans.

Mandarin Peels-Derived Carbon Dots: A Multifaceted Fluorescent Probe for Cu(II) Detection in Tap and Drinking Water Samples.

Carbon dots (CDs) derived from mandarin peel biochar (MBC) at different pyrolysis temperatures (200, 400, 600, and 800 °C) have been synthesized and characterized. This high-value transformation of waste materials into fluorescent nanoprobes for environmental monitoring represents a step forward towards a circular economy. In this itinerary, CDs produced via one-pot hydrothermal synthesis were utilized for the detection of copper (II) ions. The study looked at the spectroscopic features of biochar-derived CDs. The selectivity of CDs obtained from biochar following carbonization at 400 °C (MBC400-CDs towards various heavy metal ions resulted in considerable fluorescence quenching with copper (II) ions, showcasing their potential as selective detectors. Transmission electron microscopic (TEM) analysis validated the MBC-CDs' consistent spherical shape, with a particle size of <3 nm. The Plackett-Burman Design (PBD) was used to study three elements that influence the F0/F ratio, with the best ratio obtained with a pH of 10, for 10 min, and an aqueous reaction medium. Cu (II) was detected over a dynamic range of 4.9-197.5 μM and limit of detection (LOD) of 0.01 μM. Validation testing proved the accuracy and precision for evaluating tap and mountain waters with great selectivity and no interference from coexisting metal ions.

Unveiling the Power of Surfactant-Based Carbon Dots: Ultrasensitive Detection of Cadmium in Tap and Drinking Water Samples

This study introduces a novel approach for transforming the cationic surfactant, cetyltrimethylammonium bromide (CTAB), into fluorescent carbon dots (CDs) capable of detecting cadmium ions at ultralow concentrations. The current approach involves preparing CDs through hydrothermal process at various pH levels. The CDs synthesized using pH 10, CTAB-CDs-10, exhibited the highest fluorescence quantum yield (QY), 14.22%. UV-Vis spectroscopy helped identify specific peaks between 210 and 300 nm, corresponding to the π–π* transitions of the aromatic C=C bonds. Transmission electron microscopic (TEM) analysis verified the uniform spherical morphology with a particle size &lt; 2.45 nm. FT-IR analysis confirmed the presence of C=C stretching vibrations. The Box–Behnken (BB) Design was used to reconnoiter the influence of three variables on the response parameter: the F0/F ratio. The best performance could be achieved at a pH of 9, after only 300 s, and a temperature of 50 °C. The developed CTAB-CDs-based nanoprobe showed an ON–OFF behavior when came in contact with cadmium (II) and demonstrated high sensitivity with a limit of detection as low as 0.06 µM (0.007 ppm) over a wide linear range of 2–103 µM. Validation tests confirmed the applicability of the CTAB-CDs-based nanoprobe for detecting cadmium (II) in tap and drinking waters with high accuracy and precision.

Occurrence of per- and polyfluoroalkyl substances in drinking water in China and health risk assessment based on a probabilistic approach

Per- and polyfluoroalkyl substances (PFASs) raise concerns due to their widespread distribution, persistence, and toxicity to humans. Current studies lack the use of exposure parameters for Chinese populations and probabilistic risk assessment (PRA) to assess health risks of PFASs. To provide a scientific basis for the standards of PFASs in drinking water in China, data on concentrations of nine PFASs in 649 drinking water samples were collected from China through literature review. The highest concentration of PFASs was 17.41 ± 20.06 ng/L for perfluorobutyric acid (PFBA). Higher concentrations of PFASs were found in the southeastern coastal and in Sichuan Province. The probability of exceeding the standardized limits for drinking water for PFOA and PFOS was 2.71 % and 0.91 %. PRA and deterministic risk assessment (DRA) were used to assess non-carcinogenic risks in different age groups and provinces. Health risks of PFASs from oral exposure notably exceeded dermal contact. The Hazard Quotient (HQ) for oral exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) exceeded the acceptable level with a certain probability. The non-carcinogenic risk of exposure to PFASs in drinking water was negligible for the majority of the Chinese population. The study indicates that China should increase research on limits of PFASs in drinking water to reduce the health risks.

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

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

Ammonia Level in Drinking Water and its Health Effects in Khartoum State, Sudan

Background: Ammonia has hazardous health effects on humans. To begin with, inhalation of ammonia can be harmful to the respiratory system. The main aim of this study is to determine the concentrations of ammonia in water and evaluate its effects on human health. Methods: In this study, 20 drinking water samples were collected from different locations in Khartoum State, Sudan. Results: The concentration of ammonia (〖NH〗_3-N) ranged between 0.01 and 1.96 mg/L. The concentration of 〖NH〗_3-N reported higher than World Health Organization (WHO) standard (0.2 mg/L) in 55% of the collected samples. A questionnaire was distributed to 124 participants from different origins to measure their level of awareness about the effect of ammonia on health. Conclusions: According to the results of the questionnaire and chemical analysis, raising awareness about ammonia is needed. Furthermore, periodical testing and monitoring of drinking water is also necessary to do treatment for polluted water with ammonia.

Geographical and environmental factors in pharmaceuticals and personal care products removal from drinking water plants

Pharmaceuticals and personal care products (PPCPs) are unintentionally released into the environment from treated and untreated wastewater, agricultural runoff, and stormwater, and enter drinking water treatment plants (DWTPs). However, very little is known about the occurrence of PPCPs and their removal effectiveness during the drinking water treatment processes (conventional or advanced treatment) in multiple DWTPs, especially within the same geographical area. To address this important knowledge gap, source and finished drinking water samples were collected monthly from May to September in 2018 and 2019 from four DWTPs in Northern Ohio, USA. The total and individual PPCP concentrations varied among DWTPs and sampling dates in both source and finished water. Despite the site and time differences, caffeine and 17-beta-estradiol were detected at a frequency of 100% in all four DWTPs on all dates, while acetaminophen, estrone and nicotine consistently were not detected. Significant correlations were identified between the source water PPCPs and some environmental variables, such as dissolved organic carbon (DOC), temperature and pH. The PPCP removal efficiency from finished water samples varied depending on DWTP (61.2–84.2%), sampling month (28.3–89.7%), and different PPCP compounds (31.2% and 99.3%). Overall, this study demonstrated that PPCPs were consistently present in low concentrations (ng/L) in the freshwater systems; conventional treatment methods could only partially mitigate PPCP contaminants, while advanced techniques, such as UV-peroxide treatment, provided better removal efficiencies. PPCP removal also depended on the season, with summer demonstrating the highest removal in all four treatment plants.

Bacteriological Evaluation of Drinking Water Quality from Kabul University Taps

Human health is significantly affected by poor-quality drinking water, and water-borne diseases are of the most significant concern. A wide variety of microorganisms contaminate drinking water. Water consumers face substantial challenges due to these pollutants and harmful bacteria. To evaluate the microbiological quality of drinking water samples from different places to identify and count Escherichia coli and Coliform bacteria, multiple tube fermentation technique tests (most likely 100 ml) were used. Bacteria were identified using their morphological, biochemical, and cultural characteristics. Sixty tap water samples were collected from different locations at Kabul University. Of these, 36 samples (60 %) were positive for E. coli and Coliform bacteria, and 24 (40 %) were negative. Girls’ and boys’ dormitories showed the highest bacterial contamination level among the multiple positive water samples collected from different locations. Thirty-one samples (86.1 %) of the water were contaminated with Coliform, and five (13.8 %) samples revealed contamination with E. coli. Therefore, it is suggested that all drinking water sources should plan and carry out regular bacteriological evaluations, water supply monitoring, regular treatment, and adequate sanitation.