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Environmental Health Perspectives Mar 2014Safe drinking water is essential for well-being. Although microbiological contamination remains the largest cause of water-related morbidity and mortality globally,... (Review)
Review
BACKGROUND
Safe drinking water is essential for well-being. Although microbiological contamination remains the largest cause of water-related morbidity and mortality globally, chemicals in water supplies may also cause disease, and evidence of the human health consequences is limited or lacking for many of them.
OBJECTIVES
We aimed to summarize the state of knowledge, identify gaps in understanding, and provide recommendations for epidemiological research relating to chemicals occurring in drinking water.
DISCUSSION
Assessing exposure and the health consequences of chemicals in drinking water is challenging. Exposures are typically at low concentrations, measurements in water are frequently insufficient, chemicals are present in mixtures, exposure periods are usually long, multiple exposure routes may be involved, and valid biomarkers reflecting the relevant exposure period are scarce. In addition, the magnitude of the relative risks tends to be small.
CONCLUSIONS
Research should include well-designed epidemiological studies covering regions with contrasting contaminant levels and sufficient sample size; comprehensive evaluation of contaminant occurrence in combination with bioassays integrating the effect of complex mixtures; sufficient numbers of measurements in water to evaluate geographical and temporal variability; detailed information on personal habits resulting in exposure (e.g., ingestion, showering, swimming, diet); collection of biological samples to measure relevant biomarkers; and advanced statistical models to estimate exposure and relative risks, considering methods to address measurement error. Last, the incorporation of molecular markers of early biological effects and genetic susceptibility is essential to understand the mechanisms of action. There is a particular knowledge gap and need to evaluate human exposure and the risks of a wide range of emerging contaminants.
CITATION
Villanueva CM, Kogevinas M, Cordier S, Templeton MR, Vermeulen R, Nuckols JR, Nieuwenhuijsen MJ, Levallois P. 2014. Assessing exposure and health consequences of chemicals in drinking water: current state of knowledge and research needs. Environ Health Perspect 122:213–221; http://dx.doi.org/10.1289/ehp.1206229
Topics: Drinking Water; Environmental Exposure; Environmental Monitoring; Humans; Risk Assessment; Water Pollutants, Chemical
PubMed: 24380896
DOI: 10.1289/ehp.1206229 -
Microbiology Spectrum Dec 2021Reconstructing microbial genomes from metagenomic short-read data can be challenging due to the unknown and uneven complexity of microbial communities. This complexity...
Reconstructing microbial genomes from metagenomic short-read data can be challenging due to the unknown and uneven complexity of microbial communities. This complexity encompasses highly diverse populations, which often includes strain variants. Reconstructing high-quality genomes is a crucial part of the metagenomic workflow, as subsequent ecological and metabolic inferences depend on their accuracy, quality, and completeness. In contrast to microbial communities in other ecosystems, there has been no systematic assessment of genome-centric metagenomic workflows for drinking water microbiomes. In this study, we assessed the performance of a combination of assembly and binning strategies for time series drinking water metagenomes that were collected over 6 months. The goal of this study was to identify the combination of assembly and binning approaches that result in high-quality and -quantity metagenome-assembled genomes (MAGs), representing most of the sequenced metagenome. Our findings suggest that the metaSPAdes coassembly strategies had the best performance, as they resulted in larger and less fragmented assemblies, with at least 85% of the sequence data mapping to contigs greater than 1 kbp. Furthermore, a combination of metaSPAdes coassembly strategies and MetaBAT2 produced the highest number of medium-quality MAGs while capturing at least 70% of the metagenomes based on read recruitment. Utilizing different assembly/binning approaches also assists in the reconstruction of unique MAGs from closely related species that would have otherwise collapsed into a single MAG using a single workflow. Overall, our study suggests that leveraging multiple binning approaches with different metaSPAdes coassembly strategies may be required to maximize the recovery of good-quality MAGs. Drinking water contains phylogenetic diverse groups of bacteria, archaea, and eukarya that affect the esthetic quality of water, water infrastructure, and public health. Taxonomic, metabolic, and ecological inferences of the drinking water microbiome depend on the accuracy, quality, and completeness of genomes that are reconstructed through the application of genome-resolved metagenomics. Using time series metagenomic data, we present reproducible genome-centric metagenomic workflows that result in high-quality and -quantity genomes, which more accurately signifies the sequenced drinking water microbiome. These genome-centric metagenomic workflows will allow for improved taxonomic and functional potential analysis that offers enhanced insights into the stability and dynamics of drinking water microbial communities.
Topics: Algorithms; Archaea; Bacteria; Drinking Water; Genome, Archaeal; Genome, Bacterial; High-Throughput Nucleotide Sequencing; Metagenome; Metagenomics; Microbiota; Time Factors; Water Microbiology; Water Quality
PubMed: 34730411
DOI: 10.1128/Spectrum.01434-21 -
Comptes Rendus Biologies 2013Water is at the center of the plant and animal life, the foundation upon which the health of human settlement and development of civilizations rely on. In tropical...
Water is at the center of the plant and animal life, the foundation upon which the health of human settlement and development of civilizations rely on. In tropical regions, 80% of diseases are transmitted either by germs in the water, or by vectors staying in it. In Sub-Saharan Africa, statistics show particularly high levels of unmet needs of populations in access to drinking water in a context of socioeconomic development. For this purpose, this study aims to determine the influence of access to drinking water on the health of populations in Sub-Saharan Africa. Using data from Demographic and Health Surveys (DHS) from Cameroon, Senegal and Chad, it is clear from the descriptive analysis that 60% (Cameroon), and 59% (Chad) of the cases of childhood diarrhea in these two countries are due to the consumption of dirty water. In terms of explanatory analysis, we note that when a household in Cameroon, Senegal or Chad does not have access to drinking water, children under 5 years old residing there are respectively 1.29, 1.27 and 1.03 times more likely to have diarrhea than those residing in households with easy access to drinking water. In view of these results, it is recommended to increase access to drinking water in particular by reducing disparities between the rich and poor people.
Topics: Adult; Africa South of the Sahara; Cameroon; Child; Demography; Diarrhea; Drinking Water; Female; Health Status; Humans; Male; Multivariate Analysis; Population; Rural Population; Senegal; Urban Population; Water Microbiology; Water Pollution; Water Supply
PubMed: 23916208
DOI: 10.1016/j.crvi.2013.06.001 -
Water Research Jan 2021While it seems indisputable that potable water contains microplastics (MP), the actual concentrations are much debated and reported numbers vary many orders of...
While it seems indisputable that potable water contains microplastics (MP), the actual concentrations are much debated and reported numbers vary many orders of magnitude. It is difficult to pinpoint the cause of these differences, but it might be variation between waters, variation between quantification methods, and that some studies did not live up to rigorous analytical standards. Despite the urgent need to understand human exposure by drinking water, there is a lack of trustable methods generating reliable data. Essentially, proper MP assessment requires that quality assurance is in place and demonstrated, that an adequate volume of drinking water is assessed, and that differences in analytical methods are understood. This study presents a systematic and robust approach where MP down to 6.6 µm were assessed in potable water distribution systems in terms of quantity, size, shape, and material. For the first time, sub-samples were analysed by two of the most validated and complementary analytical techniques: µFTIR imaging and Py-GCMS. Both methods successfully determined low contents in drinking water. However, µFTIR and Py-GCMS identified different polymer types in samples with overall low MP content. With increasing concentration of a given polymer type, the values determined by the techniques became more comparable. Most detected MPs were smaller than 150 µm, and 32% were smaller than 20 µm. Our results indicate a potential annual uptake of less than one MP per person, suggesting that drinking potable water produced at a high-performance drinking water treatment plant represents a low risk for human health.
Topics: Drinking Water; Environmental Monitoring; Gas Chromatography-Mass Spectrometry; Humans; Microplastics; Plastics; Water Pollutants, Chemical
PubMed: 33091805
DOI: 10.1016/j.watres.2020.116519 -
Dental and Medical Problems 2023Endemic fluorosis (skeletal and dental) is a serious public health problem in many parts of the world, especially in India. Age, sex, dietary calcium (Ca), the hormonal...
BACKGROUND
Endemic fluorosis (skeletal and dental) is a serious public health problem in many parts of the world, especially in India. Age, sex, dietary calcium (Ca), the hormonal status, the dose and duration of the fluoride intake, and renal efficiency in handling fluoride all influence fluoride metabolism.
OBJECTIVES
The aim of the study was to evaluate the effect of the fluoride present in drinking water on the serum alkaline phosphatase (ALP) and phosphate levels in pregnant women and newborn infants.
MATERIAL AND METHODS
In the present cross-sectional study, the participants were categorized into 2 groups based on a fluoride concentration in their drinking water: the low/optimum-fluoride group (<1 ppm); and the high-fluoride group (≥1 ppm). Each group was comprised of 90 pregnant women who were recruited from the hospital at the time of admission for delivery. Fluoride was measured in their drinking water, urine, maternal serum, and cord blood. The ALP and phosphate levels were measured in serum using a fully automated analyzer.
RESULTS
The drinking water consumed by the pregnant women contained fluoride, which was significantly positively correlated with the urine and blood serum fluoride levels. There were significant differences in the ALP levels between the 2 groups in both maternal serum and cord blood. The level of phosphate in maternal serum was significantly higher in the high-fluoride group. The results of both simple and multivariate regression analyses revealed that the fluoride content in drinking water was significantly associated with the ALP level in cord blood and the phosphate level in maternal serum.
CONCLUSIONS
The ALP levels were negatively associated with drinking water fluoride concentrations in both maternal serum and cord blood. The phosphate levels in maternal serum were positively associated with drinking water fluoride concentrations.
Topics: Infant, Newborn; Humans; Female; Pregnancy; Fluorides; Drinking Water; Alkaline Phosphatase; Pregnant Women; Cross-Sectional Studies; Phosphates
PubMed: 37555277
DOI: 10.17219/dmp/132692 -
Ambio Apr 2017Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are found in aquatic systems, flora, and fauna worldwide. These potentially harmful compounds are also frequently... (Review)
Review
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are found in aquatic systems, flora, and fauna worldwide. These potentially harmful compounds are also frequently detected in Sweden and have already resulted in severe problems for public drinking water supply, i.e., some wells had to be closed due to high PFAS concentrations both in raw water and produced drinking water. Knowledge on PFAS occurrence in Sweden is still quite low, although monitoring is currently ongoing. This work describes potential sources for PFASs to enter the drinking water supply in Sweden and compares different occurrences of PFASs in raw and drinking water in the country. Moreover, the monitoring history, the legal situation, and remediation actions taken are presented. Finally, future challenges and the way forward in Sweden are discussed.
Topics: Drinking Water; Environmental Monitoring; Fresh Water; Groundwater; Hydrocarbons, Fluorinated; Sweden; Water Pollutants, Chemical
PubMed: 27844420
DOI: 10.1007/s13280-016-0848-8 -
Environmental Pollution (Barking, Essex... Oct 2022Use of per- and polyfluoroalkyl substance (PFAS)-containing aqueous film-forming foams (AFFF) at firefighting training sites (FFTS) has been linked to PFAS contamination...
Use of per- and polyfluoroalkyl substance (PFAS)-containing aqueous film-forming foams (AFFF) at firefighting training sites (FFTS) has been linked to PFAS contamination of drinking water. This study investigated PFAS transport and distribution in an urban groundwater aquifer used for drinking water production that has been affected by PFAS-containing AFFF. Soil, sediment, surface water and drinking water were sampled. In soil (n = 12) at a FFTS with high perfluorooctane sulfonate (PFOS) content (87% of ∑PFAS), the ∑PFAS concentration (n = 26) ranged from below detection limit to 560 ng g dry weight. In groundwater (n = 28), the ∑PFAS concentration near a military airbase FFTS reached 1000 ng L. Principal component analysis (PCA) identified the military FFTS as the main source of PFAS contamination in drinking water wellfields >10 km down-gradient. Groundwater samples taken close to the military FFTS site showed no ∑PFAS concentration change between 2013 and 2021, while a location further down-gradient showed a transitory 99.6% decrease. Correlation analysis on PFAS composition profile indicated that this decrease was likely caused by dilution from an adjacent conflating aquifer. ∑PFAS concentration reached 15 ng L (PFOS 47% and PFHxS 41% of ∑PFAS) in surface river water (n = 6) and ranged between 1 ng L and 8 ng L (PFHxS 73% and PFBS 17% of ∑PFAS) in drinking water (n = 4). Drinking water had lower PFAS concentrations than the wellfields due to PFAS removal at the water treatment plant. This demonstrates the importance of monitoring PFAS concentrations throughout a groundwater aquifer, to better understand variations in transport from contamination sources and resulting impacts on PFAS concentrations in drinking water extraction areas.
Topics: Alkanesulfonic Acids; Drinking Water; Fluorocarbons; Groundwater; Soil; Sweden; Water Pollutants, Chemical
PubMed: 35988673
DOI: 10.1016/j.envpol.2022.119981 -
Poultry Science Oct 2018The ban on the use of antibiotic feed additives as growth promoters compelled the researchers for exploring the future utility of other alternatives. This experiment was...
The ban on the use of antibiotic feed additives as growth promoters compelled the researchers for exploring the future utility of other alternatives. This experiment was designed to evaluate the effect of acidified drinking water on growth performance, gastrointestinal pH, digestive enzymes, intestinal histomorphology, and cecum microbial counting of the broiler chicken. A total of 540 one-day-old male broilers (Arbor Acre) were randomly assigned to 5 treatments, with 6 replicates of 18 chicks per replicate. Broilers received diets and water as follows: NC (negative control, basal diet, normal water), PC (positive control, basal diet + 8 ppm colistin sulfate + 8 ppm enduracidin, normal water), A1 (basal diet, continuous supply of acidified water during whole experiment period), A2 (basal diet, intermittent acidification of water during 0 to 14 d, 22 to 28 d, and 36 to 42 d), and A3 [basal diet, intermittent acidification of water (24 h/d from 0 to 14 d and from 10:00 am to 4:00 pm on d 15 to 42)]. During the entire period, the acidified groups (A1, A2, and A3) and PC group showed improve on weight gain, average daily gain and feed conversion ratio compared to NC group (P < 0.05). The pH in crop, proventriculus and ileum at 43 d declined by 0.04, 1.03, 1.23; 0.55, 0.69, 0.70; and 0.63, 0.74, 1.21 in A1, A2, and A3 group, respectively. There was a significant decline of lipase activity in the PC and acidified groups compared to NC group. The A2 group had higher villus height in jejunum than NC group. The PC and acidified groups reduced (P < 0.05) the total aerobic bacteria count of cecum when contrasted to NC group. Therefore, we conclude that acidified drinking water can improve growth performance, compensate for gastric acidity, and control pathogenic bacteria in broilers and may be considered as a potential alternative to improve production parameters. Discontinuous supply of acidified water had the same or even better influence on broilers compared to continuous supply.
Topics: Animal Nutritional Physiological Phenomena; Animals; Chickens; Digestion; Drinking Water; Gastrointestinal Microbiome; Gastrointestinal Tract; Hydrogen-Ion Concentration; Male; Random Allocation
PubMed: 29860532
DOI: 10.3382/ps/pey212 -
Journal of Environmental and Public... 2021The quality of drinking water has always been a major public health concern, especially in developing countries where access to improved water supply and sanitation is...
The quality of drinking water has always been a major public health concern, especially in developing countries where access to improved water supply and sanitation is very low. This study aimed to assess the bacteriological and physicochemical quality of rural community drinking water sources in the Guto Gida district. A cross-sectional study was conducted in selected rural areas of the district from January to June 2016. Water samples were collected from four types of sources (protected dug well, open dug well, protected spring, and open spring) found in 8 locations of the study area. The membrane filtration technique was employed to determine the total coliform and faecal coliform load of the samples. The physicochemical characteristics such as total dissolved solid (TDS), pH, electrical conductivity (EC), turbidity, temperature, color, iron, manganese, lead, fluoride, zinc, sulphate, nitrate, and phosphate were analyzed following the American Public Health Association and WHO standard protocols. Our results revealed that 90.6% and 87.5% of water samples were positive for total coliform and faecal coliform, respectively. Thus, the majority of the studied water sources could be classified as polluted with respect to coliform load. Our results also have shown that most of the water sources showed marginally tolerable quality with respect to color, EC, TDS, turbidity, nitrate, sulphate, and phosphate. However, the protected sources had poor quality in zinc, lead, iron, manganese, and pH with values above the permissible levels. Thus, the drinking water source quality of the study areas requires appropriate interventions such as improving the existing water source infrastructure and access to sanitation services.
Topics: Cross-Sectional Studies; Drinking Water; Ethiopia; Humans; Rural Population; Water Microbiology; Water Quality; Water Supply
PubMed: 34122562
DOI: 10.1155/2021/5568375 -
Molecules (Basel, Switzerland) Jun 2021Solar water disinfection (SODIS) is one the cheapest and most suitable treatments to produce safe drinking water at the household level in resource-poor settings. This... (Review)
Review
Solar water disinfection (SODIS) is one the cheapest and most suitable treatments to produce safe drinking water at the household level in resource-poor settings. This review introduces the main parameters that influence the SODIS process and how new enhancements and modelling approaches can overcome some of the current drawbacks that limit its widespread adoption. Increasing the container volume can decrease the recontamination risk caused by handling several 2 L bottles. Using container materials other than polyethylene terephthalate (PET) significantly increases the efficiency of inactivation of viruses and protozoa. In addition, an overestimation of the solar exposure time is usually recommended since the process success is often influenced by many factors beyond the control of the SODIS-user. The development of accurate kinetic models is crucial for ensuring the production of safe drinking water. This work attempts to review the relevant knowledge about the impact of the SODIS variables and the techniques used to develop kinetic models described in the literature. In addition to the type and concentration of pathogens in the untreated water, an ideal kinetic model should consider all critical factors affecting the efficiency of the process, such as intensity, spectral distribution of the solar radiation, container-wall transmission spectra, ageing of the SODIS reactor material, and chemical composition of the water, since the substances in the water can play a critical role as radiation attenuators and/or sensitisers triggering the inactivation process.
Topics: Disinfection; Drinking Water; Humans; Polyethylene Terephthalates; Poverty; Solar Energy; Water Microbiology
PubMed: 34198857
DOI: 10.3390/molecules26113431