Drinking Water Samples Research Articles

Detection of Salmonella Typhi bacteriophages in surface waters as a scalable approach to environmental surveillance.

Environmental surveillance, using detection of Salmonella Typhi DNA, has emerged as a potentially useful tool to identify typhoid-endemic settings; however, it is relatively costly and requires molecular diagnostic capacity. We sought to determine whether S. Typhi bacteriophages are abundant in water sources in a typhoid-endemic setting, using low-cost assays. We collected drinking and surface water samples from urban, peri-urban and rural areas in 4 regions of Nepal. We performed a double agar overlay with S. Typhi to assess the presence of bacteriophages. We isolated and tested phages against multiple strains to assess their host range. We performed whole genome sequencing of isolated phages, and generated phylogenies using conserved genes. S. Typhi-specific bacteriophages were detected in 54.9% (198/361) of river and 6.3% (1/16) drinking water samples from the Kathmandu Valley and Kavrepalanchok. Water samples collected within or downstream of population-dense areas were more likely to be positive (72.6%, 193/266) than those collected upstream from population centers (5.3%, 5/95) (p=0.005). In urban Biratnagar and rural Dolakha, where typhoid incidence is low, only 6.7% (1/15, Biratnagar) and 0% (0/16, Dolakha) river water samples contained phages. All S. Typhi phages were unable to infect other Salmonella and non-Salmonella strains, nor a Vi-knockout S. Typhi strain. Representative strains from S. Typhi lineages were variably susceptible to the isolated phages. Phylogenetic analysis showed that S. Typhi phages belonged to the class Caudoviricetes and clustered in three distinct groups. S. Typhi bacteriophages were highly abundant in surface waters of typhoid-endemic communities but rarely detected in low typhoid burden communities. Bacteriophages recovered were specific for S. Typhi and required Vi polysaccharide for infection. Screening small volumes of water with simple, low-cost (~$2) plaque assays enables detection of S. Typhi phages and should be further evaluated as a scalable tool for typhoid environmental surveillance.

AMMONIUM, NITRATE AND NITRITE CONCENTRATIONS IN DRINKING WATER OF THE SOUTH BAČKA DISTRICT OF VOJVODINA

Safe drinking water is one of the basic conditions for life on our planet, necessary for all vital processes in the biosphere. Pollution of water sources, largely from wide-scale agricultural fertilizer use, has resulted in nitrate and nitrite contamination of drinking water. Aim: To determine the concentrations of ammonium, nitrate, and nitrite in drinking water as potential hazards in the settlements of the South Bačka administrative district of Autonomous Province of Vojvodina (northern part of Serbia). A cross-sectional study was conducted during 2019. We analysed 8434 drinking water samples (7319 purified chlorinated, 386 untreated but chlorinated, and 729 untreated). For assessing the concentration of ammonium, nitrate, and nitrite in drinking water, samples were analyzed by a certified laboratory at the Institute of Public Health of Vojvodina using spectrophotometric method. After analyzing samples of purified chlorinated, untreated chlorinated, and untreated water, the exceedance of the prescribed values of ammonium were found in 0.45%, 64.77% and 68.45%, and for nitrites in 0.04%, 5.96% and 0.82% of the samples, respectively. The concentration of nitrate in drinking water concerning the degree of water purification (purified chlorinated and untreated water) exceeded the prescribed value in 0.01% and 5% of the samples, respectively. Determined exceedances of the prescribed limit values for nitrite concentrations recorded in purified chlorinated, untreated chlorinated, and untreated drinking water as well as for nitrate mainly in untreated drinking water, could be considered as potential hazards for human health, especially for the sensitive population group.

Impact of non-aged and UV-aged microplastics on the formation of halogenated disinfection byproducts during chlorination of drinking water and its mechanism

Microplastics (MPs) are ubiquitously present in source water and undergo ultraviolet (UV) aging in aquatic environments before entering drinking water treatment plants. The presence of MPs in drinking water can impact the formation of halogenated disinfection byproducts (DBPs) during chlorine disinfection, yet the exact effect of MPs on DBP formation remain unclear. In this study, we conducted an investigation into the influence of non-aged and UV-aged MPs on halogenated DBP formation in drinking water and unveiled the underlying mechanisms. In comparison to source water samples devoid of MPs, the total organic halogen concentration was reduced by 19%–43% and 4%–13% in the drinking water samples containing non-aged and aged MPs, respectively. The differing effects on halogenated DBP formation can be attributed to the alternation in physical and chemical characteristics of MPs following UV aging. Aged MPs exhibited larger surface area with signs of wear and tear, heightened hydrophilicity, surface oxidation, increased oxygen-containing functional groups and dechlorination during the UV aging process. Both non-aged and aged MPs possess the capability to adsorb natural organic matter, leading to a reduction in the concentration of DBP precursors in the source water. However, the release of organic compounds from aged MPs outweighed the adsorption of organics. Furthermore, as a result of the surface activation of MPs through the UV aging process, the aged MPs themselves can also serve as DBP precursors. Consequently, the presence of halogenated DBP precursors in source water increased, contributing to a higher level of DBP formation compared to source water containing non-aged MPs. Overall, this study illuminates the intricate relationship among MPs, UV aging, and DBP formation in drinking water. It highlights the potential risks posed by aged MPs in influencing DBP formation and offers valuable insights for optimizing water treatment processes.

Effect of water quality on causes of calf mortality in cattle-farm-associated epidemics

Abstract. Poor-quality drinking water plays a detrimental role in the suppression of calf immunity, giving rise to an increased rate of calf mortality. The present study aims to evaluate the causes of calf mortality in beef and dairy farms in relation to drinking water quality (DWQ). A convenience sample of 132 Egyptian cattle farms suffering from emerging epidemics was surveyed by collecting drinking water samples for physicochemical and microbial analysis and using a questionnaire to record hygienic risk factors affecting calf health. Statistical analysis correlates water parameters with rates of calf diarrhea, respiratory problems, severe depression, sudden death and mortality. High percentages of water sample quality parameters, e.g. pH, total dissolved solids (TDSs), hardness, chloride, nitrate, sulfate, total colony count (TCC) and total coliform count (TCFC), are above permissible limits. Water parameters, except pH, show a significant moderate positive correlation with causes of calf mortality (ρ 0.331–0.66) in winter and summer. Each cause of calf mortality was predicted by a specific water parameter, and the water nitrate level was the highest predictor, with the highest values (β = 0.504–0.577), followed by the water TDS, sulfate and microbial levels. Weak to moderate correlation (ρ 0.151–0.367) was found between calf mortality causes and some hygienic risk factors such as operation type, calf housing, calf feeders, bedding type, water source, water pipe type, drinker lining and wheel dipping. We could conclude that DWQ greatly affects causes of calf mortality, but we cannot exclude some farm hygienic risk factors.

Appraisal of trace metals toxicity and human health risk using a novel approach in wastewater of four gas fields, Bangladesh

The objective of this study is to assess the toxicity of trace metals (TMs) and associated environmental, ecological and health risks in the gas fields located in the Sylhet region of Bangladesh. Gas well-produced water, gas field discharge water, and drinking water surrounding the gas fields were collected for analysis. This study analyzed carcinogenic and noncarcinogenic TMs such as Cr, As, Co, Cd, Fe, Ni, Mn, Zn, and Pb, as well as physical parameters pH and EC in the collected samples using various instruments. The TMs were measured using Atomic Absorption Spectrometer (AAS), Flame AAS and physical parameters were evaluated using portable water multiparameter. The Fe and EC concentrations in produced and discharged water samples were incredibly high. The average concentrations of TMs in produced water samples during the summer and rainy seasons were found to be Fe > Mn > Zn > Ni > Co > Cu > Cr > Pb > As > Cd. The observed metal concentration in discharge water was higher during the summer than in the rainy season. Most samples met national and international standards for trace elements, while a few samples exceeded the threshold value.The Heavy Metal Evaluation Index (HMEI) results indicate that most produced water is highly polluted, while discharge and drinking water are moderate to lightly polluted. The Environmental Pollution Index (EPI) indicates environmental pollution for some produced water samples, while it indicates a moderate to low risk for discharge and drinking water samples. The source of trace metals (TMs) was determined using positive matrix factorization. However, all water samples have an ecological risk index of less than 150, indicating lower risk. Furthermore, the Heavy Metals Toxicity Load (HMTL) was below the allowable toxicity load for all water samples, indicating minimal contamination in the studied water. The non-cancer hazard score (HI) of the studied HMs is more significant for children and females than males. The cancer risk from Ni is a concern, while the cancer risk from Cd and Cr is also a matter of concern. In the end, policymakers can utilize this study's findings to monitor, and control produced water contamination.

Determination of 145 pharmaceuticals and personal care products in eleven categories in water by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants frequently detected in aquatic environments at trace levels. These chemicals have diverse structures and physicochemical properties and includes pharmaceuticals like antibiotics, antihypertensive drugs, antiviral drugs, and psychotropic drugs that are widely used in large quantities worldwide. Considering the large number of pharmaceuticals currently in usage, it is crucial to establish a priority list of PPCPs that should be monitored and/or treated first. An accurate understanding of the occurrence and levels of PPCPs in aquatic environments is essential for providing objective materials for monitoring these emerging contaminants. Therefore, accurate, efficient, sensitive, and high-throughput screening techniques need to be established for determining and quantifying PPCPs. This study developed a method for the determination of 145 PPCPs (grouped into eleven categories: antibiotics, antihypertensive drugs, antidiabetic drugs, antiviral drugs, β-receptor agonists, nitroimidazoles, H2 receptor antagonists, psychotropic drugs, hypolipidemic drugs, non-steroidal anti-inflammatory drugs, and others) in water. The method was based on large volume direct injection without sample enrichment and cleanup and used ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UHPLC-MS/MS). Water samples were collected and filtered through a 0.22-μm regenerated cellulose (RC) filter membrane. Subsequently, Na2EDTA was added to the samples to adjust their pH to 6.0-8.0. Internal standards were mixed with the solutions, and because of the addition of Na2EDTA, the interference of metal ions could be eliminated in the determination of compounds, especially for tetracycline and quinolone antibiotics. Among the six filter membranes tested in this study (PES, PFTE-Q, PFTE, MCE, GHP, and RC), RC filter membranes were screened for water sample filtration. The UHPLC-MS/MS parameters were optimized by comparing the results of various mobile phases, as well as by establishing the best instrumental conditions. The 145 PPCPs were separated using an Phenomenex Kinetex C18 column (50 mm×3 mm, 2.6 μm) via gradient elution. The mobile phases were 0.1% (v/v) formic acid aqueous solution containing 5 mmol/L ammonium formate and acetonitrile for positive ion modes, 5 mmol/L aqueous solutions of ammonium formate and acetonitrile for negative ion modes. The samples were quantified using the scheduled multiple reaction monitoring (scheduled-MRM) mode with electrospray ionization in positive and negative ion modes. A standard internal calibration procedure was used to calculate contents of sample. The established method was systematically verified, and it demonstrated a good linear relationship. The average recoveries of the 145 PPCPs at the three spiked levels were in the range of 80.4%-128% with relative standard deviations (RSDs, n=6) of 0.6%-15.6%. The method detection limits (MDLs) ranged from 0.015 to 5.515 ng/L. Finally, the optimization method was applied to analyze the 145 PPCPs in 11 surface water samples and 6 drinking water samples. Overall, 93 (64%) out of the 145 analytes were detected. The total contents of the PPCPs in surface water samples ranged from 276.9 to 2705.7 ng/L. The detection frequencies of antidiabetic, antiviral, and psychotropic drugs were 100%. The total contents of the PPCPs in drinking water samples ranged from 140.5 to 211.5 ng/L, and antibiotics, antidiabetic drugs, and antiviral drugs comprised the largest proportion of analytes (by mass concentration) in drinking water samples. Our method exhibited high analytical speed and high sensitivity. It is thus suitable for the trace analysis and determination of the 145 PPCPs in environmental water and showed improved detection efficiency for PPCPs in water, indicating that it has a high potential for practical applications. This study can extend technical support for further pollution-level analysis of PPCPs in water and provide an objective basis for environmental management.

High-selectivity turn-on fluorescence-based fluoride ion detection using histidine-functionalized UiO-66-NH2.

Hisditine-functionalized UiO-66-NH2 (UiO-66-NH2@Hst) as a novel "turn-on" fluorescent probe to detect fluoride ions has been successfully synthesized using the solvothermal method. The results showed that fluoride ion detection gave the best fluorescence response in water media and no response was observed in non-polar solvents. Detection at pH 3-10 produces a relatively similar fluorescence response and decreases quite significantly at pH 11-13. UiO-66-NH2@Hst is very selective and stable towards fluoride ions as evidenced by the appearance of blue luminescence under UV light (λ 365 nm) compared to other ions. A possible mechanism for detecting fluoride ions is through the formation of hydrogen bonds, which results in incremental electron transfer from organic ligands to Zr-oxo clusters. The LoD value obtained in this study was 0.013 ppm, which is smaller than the maximum concentration of fluoride ions in drinking water samples (1.5 ppm) set by the World Health Organization (WHO). Therefore, UiO-66-NH2@Hst can be a candidate fluorescence-based sensor for fluoride ions.

Assessment of the Physicochemical Properties of Drinking Water in Gwagwalada Area Council, Federal Capital Territory, Abuja, Nigeria.

Background of the study: Good quality drinking water is essential for human physiology, but its availability remains a challenge especially Nigeria. The need to ascertain physicochemical quality of water to determine safety becomes paramount. The qualities of selected sachet, tap and bottled water produced and most consumed within Gwagwalada Area Council Abuja were analyzed to determine their physicochemical properties. Methods: Six different brands of most consumed drinking water samples were collected within Gwagwalada metropolis. Twenty (20) physicochemical parameters in six (6) brands of drinking water samples which include, temperature, alkalinity, Total hardness, acidity, dissolved oxygen, color, taste, total dissolved solid were analyzed using standard procedure. Results: The Temperature (28.3-28.7◦C), Hardness (1000-2000 mg/L), Alkalinity (12-18.1 mg/L), Acidity (8-28 mg/L), Magnesium (0.1421-0.2085 mg/L), Sulphate (2.71-15.99 mg/L), Calcium (2.1165-2.6805 mg/L) and COD (18.23-30.21 mg/L) were not within the permissible limits stipulated by World Health Organization (WHO) and Nigerian Standard Drinking Water Quality (NSDWQ), while twelve (12) parameters analyzed (colour (<15), PH (6.64-7.85), Taste, Odour, Total dissolved solid (37.35-40.43 mg/L), Biological oxygen demand (3.21-4.03 mg/L), Nitrate (nil), Phosphate (0.85-1.43 mg/L), Electrical conductivity (72.33-82.53 us/cm), Iron (0.0231-0.1712 mg/L), Nickle (0.0412-0.1506 mg/L), Potassium (0.4120-2.9092 mg/L) and Phosphate(0.85-1.43 mg/L) were all within the permissible limits stipulated by WHO and NSDWQ for drinking water standard. This indicated a moderate level of conformity to specified standard procedures. Conclusion: It is highly recommended that the manufacturers of sachet, bottle and tap water should keep to WHO and NSDWQ standards to safeguard public health.

Development and validation of voltammetric method to determination of bisphenol A in drinking water samples

RESUMO O bisfenol A (BPA) é utilizado como matéria prima na fabricação do plástico e apresenta-se como um desregulador endócrino. Foi realizado o desenvolvimento e a validação de um método voltamétrico para determinação de BPA e o método foi baseado em sensores descartáveis de carbono modificados com carbon black. A voltametria de onda quadrada foi selecionada para a determinação do BPA em amostras de água mineral, comercializadas em garrafas plásticas, e este método foi validado por meio das figuras de mérito. Observou-se uma resposta linear no intervalo de concentração de 6,10 a 27,4 µmol L–1, com valores de limites de detecção e de quantificação iguais a 0,137 µmol L–1 e 0,416 µmol L–1, respectivamente. O método demonstrou seletividade adequada e boa precisão, com desvios padrão relativos entre 0,59 e 9,89%, estando abaixo do limite indicado para esta faixa de concentração. A estimativa da exatidão, em termos de recuperação média, foi obtida na faixa de 58,16 e 118,79%, estando dentro dos limites estabelecidos por órgãos reguladores. Deste modo, os resultados obtidos neste trabalho são viáveis frente a outros trabalhos já reportados na literatura para a determinação de BPA, apresentando-se como uma alternativa rápida e de baixo custo para o monitoramento deste contaminante.

A novel ratiometric design of microfluidic paper-based analytical device for the simultaneous detection of Cu2+ and Fe3+ in drinking water using a fluorescent MOF@tetracycline nanocomposite.

The regular and on-site monitoring of ions in drinking water is essential for safeguarding public health, ensuring high water quality, and preserving the ecological balance of aquatic ecosystems. Thus, developing a portable analytical device for the rapid, cost-effective, and visual on-site detection of multiple environmental pollutants is notably significant. In the present work, a novel ratiometric microfluidic paper-based analytical device (μPAD) was designed and developed for the simultaneous detection of Fe3+ and Cu2+ ions in water samples taking advantages from built-in masking zone. The μPAD was functionalized with a greenish-yellow fluorescent Zn-based metal-organic framework@tetracycline (FMOF-5@TC) nanocomposite, and the ratiometric design was based on the change in emission color from greenish yellow (FMOF-5@TC) to blue (FMOF-5). The μPAD consisted of one sample zone linked to two detection zones via two channels: the first channel was for the detection of both ions, while the second was intended for detecting only Cu2+ ions and comprised a built-in masking zone to remove Fe3+ ions prior to reaching the detection zone. The corresponding color changes were recorded with the aid of a smartphone and RGB calculations. The linear ranges were 0.1-80 μM for Cu2+ and 0.2-160 μM for Fe3+, with limits of detection of 0.027 and 0.019 μM, respectively. The simple μPAD design enabled the simultaneous detection of Cu2+ and Fe3+ ions in drinking water samples with excellent accuracy and precision, with spike recoveries of 81.28-96.36% and 83.01-102.33% for Cu2+ and Fe3+, respectively.

Chemical composition of natural waters from the Urov endemic area

Owing to the importance of drinking water in human nutrition, in this study, we performed a comparative analysis of the chemical composition of drinking water from settlements endemic to Kashin–Beck disease and from territories that are not endemic to Kashin–Beck disease. Our analysis showed that all drinking water samples were weakly alkaline and had a hydrocarbonate–calcium–magnesium composition. There were no considerable differences in mineralization, pH, or concentrations of Mg, Si, F, Se Zn, K, and Na. All waters had weak hardness specific for the waters from the northern territories. The mineral waters from the Urov biogeochemical subregion of the biosphere have elevated concentrations of Ca, Mg, Sr, Si, and Li and lower concentrations of I, Se, and Cu. The maximum Sr content was found in mineral water from the Bazanovo village, i.e., 20 mg/L, with a Ca/Sr ratio of 8 units. Owing to the inconsistency of data on the chemical composition of drinking water from the territories endemic for Kashin–Beck disease, we suggest an indirect role of biogeochemical factors in the disease pathogenesis. Previous pathologies may be important, which have arisen because of hypothermia, common cold, hormonal imbalance, and alimentary factors.

Water Quality Trade-offs for Risk Management Interventions in a Green Building.

Premise plumbing water quality degradation has led to negative health impacts from pathogen outbreaks (e.g., Legionella pneumophila and non-tuberculous mycobacteria), as well as chronic effects from exposure to heavy metals or disinfection by-products (DBP). Common water quality management interventions include flushing, heat shock (thermal disinfection), supplemental disinfection (shock or super chlorination), and water heater temperature setpoint change. In this study, a Legionella pneumophila- colonized Leadership in Energy and Environmental Design (LEED) certified building was monitored to study health-relevant water quality changes before and after three controlled management interventions: (1) flushing at several points throughout the building; (2) changing the water heater set point; and (3) a combination of interventions (1) and (2) by flushing during a period of elevated water heater set point (incompletely performed due to operational issues). Microbial (culturable L. pneumophila, the L. pneumophila mip gene, and cATP) and physico-chemical (pH, temperature, conductivity, disinfectant residual, disinfection by-products (DBPs; total trihalomethanes, TTHM), and heavy metals) water quality were monitored alongside building occupancy as approximated using Wi-Fi logins. Flushing alone resulted in a significant decrease in cATP and L. pneumophila concentrations (p = 0.018 and 0.019, respectively) and a significant increase in chlorine concentrations (p = 0.002) as well as iron and DBP levels (p = 0.002). Copper concentrations increased during the water heater temperature setpoint increase alone to 140°F during December 2022 (p = 0.01). During the flushing and elevated temperature in parts of the building in February 2023, there was a significant increase in chlorine concentrations (p = 0.002) and iron (p = 0.002) but no significant decrease in L. pneumophila concentrations in the drinking water samples (p = 0.27). This study demonstrated the potential impacts of short term or incompletely implemented interventions which in this case were not sufficient to holistically improve water quality. As implementing interventions is logistically- and time-intensive, more effective and holistic approaches are needed for informing preventative and corrective actions that are beneficial for multiple water quality and sustainability goals.

Ultrasensitive fluorometric determination of aluminum using the CoFe2O4 NPs/SDS/oxine system with the aid of ultrasound waves.

In this study, we present a thoughtful integration of a dispersive solid-phase sorbent and oxine for the ultrasensitive and highly selective determination of Al3+ ions. Cobalt ferrite nanoparticles (CoFe2O4 NPs) modified with oxine were employed to facilitate the pre-concentration and estimation of Al3+, forming highly fluorescent chelate. The modification process included the assistance of sodium dodecyl sulfate (SDS) and sonication. The results indicated that the fluorescence intensity of Al3+-oxine/SDS@CoFe2O4 NPs surpassed that of Al3+-oxine alone. The confirmation of the successful functionalization of CoFe2O4 NPs with oxine was established through various techniques. Under optimal conditions, the fluorescence intensity exhibited a positive correlation with increasing concentrations of Al3+ within the range of 0.029-600 ng mL-1, achieving a detection limit of 0.0087 ng mL-1 based on signal to noise ratio 3 : 1. The developed method was effectively applied to the determination of Al3+ in drinking water samples, yielding recoveries in the range of 97.19% to 103.13%, with a relative standard deviation (RSD%) not exceeding 3.78%.

Modulation of the enzyme-like activity of CuAsp nanozyme by gallic acid and the selective detection of bisphenol A in infant food packaging.

The activity modulation of nanozymes with multi-enzymatic activities has both opportunities and challenges in practical applications. In this study, we found firstly that gallic acid erosion had a significant inhibitory effect on the peroxidase-catalyzed colorimetric reaction process of copper aspartate nanozyme prepared based on aspartic acid and copper (CuAsp), and the laccase-like catalytic activity remained almost unchanged. A sensing strategy for bisphenol A was then developed based on the laccase-like activity of GA-CuAsp synthesized by gallic acid (GA) acid erosion of CuAsp, which may have less interference due to the peroxidase-like activity. The developed sensing strategy had good selectivity and interference resistant ability, with a detection limit of 0.75 μmol L-1. In addition, the method was successfully applied to detecting BPA in plastic bottled drinking water samples and infant food packaging.

Identifying predictors of E. coli in rural household water in sub-Saharan Africa using elimination regression.

Exposure to fecally contaminated drinking water contributes to the global disease burden, especially in sub-Saharan Africa (SSA). We used cross-sectional data and elimination regression analysis to examine factors influencing E. coli contamination in household drinking water samples from 4,499 rural households in nine countries in SSA (Malawi, Mozambique, and Zambia in Southern Africa; Ghana, Mali, and Niger in Western Africa; and Kenya, Rwanda, and Tanzania in Eastern Africa). The proportion of household water samples containing E. coli was 71%, ranging from 45% (Malawi) to 89% (Tanzania). Pooled and multi-country predictive logistic regression models showed that using an unimproved-type water source, the absence of a community water committee, and domestic animal ownership were significantly associated with household drinking water contamination. Household water treatment and storage practices, sanitation and hygiene practices, and payment for drinking water were not significantly associated with E. coli contamination in any model. The season was a significant predictor of E. coli in the pooled model; samples collected in the rainy season were 2.3 [2.0, 2.7] times as likely to be contaminated with E. coli. Practitioners and policymakers should prioritize implementing piped on-plot water services, establishing effective local water source management structures, and incorporating animal husbandry practices into water, sanitation, and hygiene interventions.

PREVALENCE OF UROLITHIASIS TYPES AND FACTORS OF STONE FORMATION AMONG LOCAL RESIDENTS OF SOUTH WAZIRISTAN

Background: Kidney stone disease (KSD), a widespread public health issue around the globe, is caused by the confluence of demography, contact with the environment, eating choices, and hereditary factors. Aims: The current study examined the prevalence of urolithiasis types and factors of stone formation among residents of Waziristan since a rising water consumption (>3 l everyday) is frequently advised by doctors to avoid kidney disease. Methods: From 110 renal stone individuals ages 18 to 55. There were 25 women and 85 men in Waziristan, and data on a household residence, daily water intake, and origin of water supply were gathered. Drinking water samples were taken twice a year from the case (high stone frequency) and control (zero stone epidemiologic) locations using the correct techniques. Potential of hydrogen (pH), acidity, total dissolved solutes (TDS), electrical conductivity (EC), and salinity were all measured in the samples collected. To see if there had been any statistically meaningful variations among the case and control regions, mean estimates of the examined variables were evaluated. Findings: 53.6% of the patients, we found, drank less than 3 L of water each day. Testing of samples from drinking water reveals calcium oxalate (CaOx) (94%) and struvite (3%), as well as 3% uric acid (UA). TDS levels were around 650 ppm. It was determined that every water sample was fit for human drinking. According to the findings, urolithiasis is quite prevalent in Waziristan and has a wide range of risk variables. Conclusions: The most important factor in the development of KSD is the purity of the water, not the quantity drank. Stone formation is influenced by genetic factors as well as higher overall solute concentrations. Supporting and advancing awareness initiatives that focus on the key urolithiasis risk variables is crucial.

Health Risk Assessment of Nitrate in Drinking Water with Potential Source Identification: A Case Study in Almaty, Kazakhstan.

Infant mortality in Kazakhstan is six times higher compared with the EU. There are several reasons for this, but a partial reason might be that less than 30% of Kazakhstan's population has access to safe water and sanitation and more than 57% uses polluted groundwater from wells that do not comply with international standards. For example, nitrate pollution in surface and groundwater continues to increase due to intensified agriculture and the discharge of untreated wastewater, causing concerns regarding environmental and human health. For this reason, drinking water samples were collected from the water supply distribution network in eight districts of Almaty, Kazakhstan, and water quality constituents, including nitrate, were analyzed. In several districts, the nitrate concentration was above the WHO and Kazakhstan's maximum permissible limits for drinking water. The spatial distribution of high nitrate concentration in drinking water was shown to be strongly correlated with areas that are supplied with groundwater, whereas areas with lower nitrate levels are supplied with surface water sources. Based on source identification, it was shown that groundwater is likely polluted by mainly domestic wastewater. The health risk for infants, children, teenagers, and adults was assessed based on chronic daily intake, and the hazard quotient (HQ) of nitrate intake from drinking water was determined. The non-carcinogenic risks increased in the following manner: adult < teenager < child < infant. For infants and children, the HQ was greater than the acceptable level and higher than that of other age groups, thus pointing to infants and children as the most vulnerable age group due to drinking water intake in the study area. Different water management options are suggested to improve the health situation of the population now drinking nitrate-polluted groundwater.

Problems of providing the Leningrad region`s population with full-fledged drinking water from underground sources

Introduction. There are about 2,900 settlements in the Leningrad Region, the centralized water supply of most of which is based on the underground aquifers’ exploitation, which water is a significant source of essential elements. &#x0D; Material and methods. The paper analyzes the results of 143,578 drinking water samples from 10 aquifers used as sources of drinking water supply. Within the framework of this study, the content of the following elements was evaluated: calcium, magnesium, potassium, copper, zinc, phosphorus, iron, manganese, selenium, molybdenum, chromium, sodium, chlorides, fluorides in comparison with the methodological recommendations of MP 2.3.1.0253–21 “Norms of physiological energy and nutritional needs for various population groups of the Russian Federation”. &#x0D; Results. None of the aquifers of the Leningrad region provide the concentrations of phosphates, copper, potassium, zinc and selenium did not satisfy 20% of the minimum required intake from drinking water. Insufficient intake of essential macro- and microelements with drinking water can become one of the causes of metabolic disorders and lead to health disorders. &#x0D; Limitations. Within the framework of this article, water quality is characterized by sanitary and chemical indicators, the chemical harmlessness of water is evaluated. The issues of microbiological and radiological safety of underground water in the Leningrad region, despite their relevance, aren`t considered in this article. In addition, the quality of drinking water in Sosnovy Bor wasn`t studied, since the centralized water supply of this locality is carried out from surface water sources.&#x0D; Conclusion. Despite the undoubted advantages of groundwater, they are not able to satisfy the physiological need of the body for macro- and microelements. In this regard, it is necessary to develop targeted preventive programs aimed at replenishing the deficiency of micro- and macroelements in the body for each territory of the Leningrad region. These include the consumption of foods rich in microelements, the intake of biologically active additives containing scarce micro- and macroelements, as well as the use of mineral waters.

Evaluation of inactivation of bacterial indicators in real drinking water using UVC-LED

Bacterial contamination of drinking water sources is a serious problem. Here, we investigated the inactivation of bacterial indicators, namely total heterotrophic bacteria, total and fecal coliform in real drinking water using UVC-LED devices. Real drinking water samples collected every fortnight for a year from five different sampling sites showed significant prevalence of bacterial indicators. Each device was made up of 9 UVC-LED chips arranged in a line on a heat sink, covered with quartz tube, and submersible in water. A UVC-LED chip had an emission maximum, wall plug efficiency, and radiant power of around 276 nm, 0.018, and 10–12 mW, respectively. Inactivation was performed with 4 UVC-LED devices placed in series in a rectangular stainless-steel chamber with 1.2 L effective volume. With 30 LPH flow rate, and corresponding energy dosage of about 10.8 mJ/cm2, all bacterial indicators (initial load about 103 CFU/100 mL) were inactivated, as required by regulatory bodies. Notably, dark repair of bacterial indicators was not significant (<1 %) up to 24 h of storage in clean opaque (dark) vessel, whereas slight photo repair of bacterial indicators was observed (<10 %). Electrical energy (EE3) for complete inactivation and cost for water disinfection were determined to be about 1.397 kWh/m3 and ₹ 9.03 (€ 0.09 or $ 0.10), respectively. The estimated cost is affordable in developing countries. The study may be a referral to develop applications of UVC-LED irradiation for point-of-use drinking water disinfection and useful for resource-poor communities challenged with bacterial contaminated drinking water.

A Dynamic Multiple Reaction Monitoring Analytical Method for the Determination of Fungicide Residues in Drinking Water

The extensive use of fungicides causes their continuous release into the environment through spraying, soil seepage, leaching, and runoff. It has been observed that their residues can be found in foods and a variety of environmental compartments, such as wastewater, lakes, rivers, sediments, drinking water sources (groundwater and surface water), treated water, and drinking water. A sensitive GC-MS/MS, using dynamic multiple reaction monitoring, an analytical method was developed to determine 10 fungicides (azoxystrobin, boscalid, captan, cyproconazole, cyprodinil, hexaconazole, metalaxyl, myclobutanil, paclobutrazol, and prochloraz) in drinking water. A solid-phase extraction method for sample preparations and validations was performed according to SANTE 2019 guidelines. All fungicides demonstrated mild or medium matrix effects (ME) ranging from 40.1% to 11.2%. Their recoveries ranged between 60% and 110%. The limits of detection were equal to or higher than 0.01 μg/L. The method was employed on 18 drinking water samples collected from public taps in Northern Evros, Greece, distributed in six sampling sites. Azoxystrobin, boscalid, cyproconazole, cypronidil, metalaxyl, and paclobutrazol mean concentrations did not surpass the allowable limit of 0.1 μg/L set by EU in any sampling site. Hexaconazole mean concentrations were higher than 0.1 μg/L in one sampling site, while prochloraz mean concentration showed limit exceedances in all sampling sites. Captan was not detected in any sampling site, and myclobutanil mean concentrations demonstrated exceedances of the permissible limit in four sampling sites. The presence of fungicide residues in the studied area is mainly due to the occasional point-sources pollution and preferential flow. Additionally, through the use of water, the risk of pesticides to human health was assessed for two different age groups. The sum of the hazard quotient values in each of the studied drinking water was less than unity. Consequently, the acute risk assessment procedure regards the examined drinking water as safe. Nevertheless, as prochloraz carcinogenic risk values were higher than the safe limit suggested by USEPA for both age groups, the existence of prochloraz residues raises concerns about chronic toxicity.