•MPs are quantified by particle number and mass using µFTIR imaging and Py-GCMS, respectively.•Low MP concentrations (0.174 MPs/L) in potable drinking water.•Detection of low MP loads in comparable ...concentrations with the two complementary techniques µFTIR and Py-GCMS.•32% of MPs were smaller than 20 µm.
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.
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Little is known about the nature of the microbiology in tap waters delivered to consumers via public drinking water distribution systems (DWDSs). In order to establish a broader understanding of the ...microbial complexity of public drinking waters we sampled tap water from seventeen different cities between the headwaters of the Arkansas River and the mouth of the Mississippi River and determined the bacterial compositions by pyrosequencing small subunit rRNA genes. Nearly 98% of sequences observed among all systems fell into only 5 phyla: Proteobacteria (35%), Cyanobacteria (29%, including chloroplasts), Actinobacteria (24%, of which 85% were Mycobacterium spp.), Firmicutes (6%), and Bacteroidetes (3.4%). The genus Mycobacterium was the most abundant taxon in the dataset, detected in 56 of 63 samples (16 of 17 cities). Among the more rare phylotypes, considerable variation was observed between systems, and was sometimes associated with the type of source water, the type of disinfectant, or the concentration of the environmental pollutant nitrate. Abundant taxa (excepting Cyanobacteria and chloroplasts) were generally similar from system to system, however, regardless of source water type or local land use. The observed similarity among the abundant taxa between systems may be a consequence of the selective influence of chlorine-based disinfection and the common local environments of DWDS and premise plumbing pipes.
Despite WHO standards, waterborne diseases among the human being are rising alarmingly. It is known that the prolong exposure to contaminated water has major impact on public health. The effect of ...chemical contaminations in drinking water on human being is found to be chronic rather than acute and hence can be defined "consumption of contaminated drinking water could be a silent killer". As the WHO recommended water quality standards are only for individual element and synergic effects of trace metals and anions have not been considered, investigation of synergic effects of trace metals and anions and their effect on human being is of prime important research. By an animal trial, we investigated the synergic effect(s) of heavy metals, aluminium, arsenic, fluoride and hardness in drinking water on kidney tissues of mice. Our investigation strongly suggests existing of a synergic effect especially among Cd, F and hardness of water which could lead to severe kidney damage in mice, even at WHO maximum recommended levels. Hence, the synergic effect(s) of trace metals, fluoride and hardness present in drinking water should be investigated meticulously when stipulating the water quality at WHO maximum recommended levels.
Availability of safe, pathogen-free drinking water is vital to public health; however, it is impossible to deliver sterile drinking water to consumers. Recent microbiome research is bringing new ...understanding to the true extent and diversity of microbes that inhabit water distribution systems. The purpose of this study was to determine how water chemistry in main distribution lines shape the microbiome in drinking water biofilms and to explore potential associations between opportunistic pathogens and indigenous drinking water microbes. Effects of disinfectant (chloramines, chlorine), water age (2.3 days, 5.7 days), and pipe material (cement, iron, PVC) were compared in parallel triplicate simulated water distribution systems. Pyrosequencing was employed to characterize bacteria and terminal restriction fragment polymorphism was used to profile both bacteria and eukaryotes inhabiting pipe biofilms. Disinfectant and water age were both observed to be strong factors in shaping bacterial and eukaryotic community structures. Pipe material only influenced the bacterial community structure (ANOSIM test, P < 0.05). Interactive effects of disinfectant, pipe material, and water age on both bacteria and eukaryotes were noted. Disinfectant concentration had the strongest effect on bacteria, while dissolved oxygen appeared to be a major driver for eukaryotes (BEST test). Several correlations of similarity metrics among populations of bacteria, eukaryotes, and opportunistic pathogens, as well as one significant association between mycobacterial and proteobacterial operational taxonomic units, provides insight into means by which manipulating the microbiome may lead to new avenues for limiting the growth of opportunistic pathogens (e.g., Legionella) or other nuisance organisms (e.g., nitrifiers).
Waterborne illness related to the consumption of contaminated or inadequately treated water is a global public health concern. Although the magnitude of drinking water-related illnesses in developed ...countries is lower than that observed in developing regions of the world, drinking water is still responsible for a proportion of all cases of acute gastrointestinal illness (AGI) in Canada. The estimated burden of endemic AGI in Canada is 20·5 million cases annually – this estimate accounts for under-reporting and under-diagnosis. About 4 million of these cases are domestically acquired and foodborne, yet the proportion of waterborne cases is unknown. There is evidence that individuals served by private systems and small community systems may be more at risk of waterborne illness than those served by municipal drinking water systems in Canada. However, little is known regarding the contribution of these systems to the overall drinking water-related AGI burden in Canada. Private water supplies serve an estimated 12% of the Canadian population, or ~4·1 million people. An estimated 1·4 million (4·1%) people in Canada are served by small groundwater (2·6%) and surface water (1·5%) supplies. The objective of this research is to estimate the number of AGI cases attributable to water consumption from these supplies in Canada using a quantitative microbial risk assessment (QMRA) approach. This provides a framework for others to develop burden of waterborne illness estimates for small water supplies. A multi-pathogen QMRA of Giardia, Cryptosporidium, Campylobacter, E. coli O157 and norovirus, chosen as index waterborne pathogens, for various source water and treatment combinations was performed. It is estimated that 103 230 AGI cases per year are due to the presence of these five pathogens in drinking water from private and small community water systems in Canada. In addition to providing a mechanism to assess the potential burden of AGI attributed to small systems and private well water in Canada, this research supports the use of QMRA as an effective source attribution tool when there is a lack of randomized controlled trial data to evaluate the public health risk of an exposure source. QMRA is also a powerful tool for identifying existing knowledge gaps on the national scale to inform future surveillance and research efforts.
Antibiotic resistance genes (ARGs) are extensively detected in various environmental media, whose risk assessment in the drinking water systems has not been comprehensive. This study established a ...new risk assessment of ARGs in the drinking water systems, considering the chlorine-resistance ability, transferability, and ARGs harboring potential of pathogens. The risk of ARGs in a typical drinking water reservoir was also evaluated based on the detection of ARGs and antibiotic-resistant bacteria (ARB). Fourteen ARGs were detected with a relative concentration range of 10-4–10-3 (ARGs/16S rRNA gene). Five isolated ARB were identified as human opportunistic pathogens, one of which (Pseudomonas aeruginosa HLS-6, CCTCC AB 2017269) is resistant to hundreds of milligrams per liter levels of antibiotics and low-level chlorine. This result indicated that ARB tolerant to high-levels of antibiotics could be isolated from environments containing trace levels of antibiotics. Moreover, complete genome sequencing confirmed the inclusion of ARGs (sul1, aadA2) on the class I integron in HLS-6, indicating that the risk of ARGs in this drinking water reservoir could be classified as resistance risk ranking in drinking water system 1 (R3DW 1). The risk assessment of ARGs in this study provides a clear understanding of ARG risk in drinking water systems. The results reveal that the ARGs and ARB contamination of drinking water reservoirs pose significant challenges for drinking water treatment efficiency and affect drinking water safety.
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•Sulfonamides ARGs were the dominant type.•Five isolated ARB were identified as human opportunistic pathogens.•ARB from trace-level-antibiotic environment show high-level antibiotics resistance.•A new risk assessment system of ARG in drinking water system is established.•The tolerance to chlorine is a vital factor in the risk assessment of ARGs.
La(OH)3 nanorods immobilized in polyacrylonitrile (PAN) nanofibers (PLNFs) were fabricated for the first time by electrospinning and a subsequent in situ surfactant-free precipitation method and then ...applied as a highly efficient phosphate scavenger to realize nutrient-starvation antibacteria for drinking water security. The immobilization by PAN nanofibers effectively facilitated the in situ formation of the aeolotropic and well-dispersed La(OH)3 nanostructures and, thus, rendered higher phosphate removal efficiency due to more exposed active sites for binding phosphate. The maximum phosphate capture capacity of La(OH)3 nanorods in PAN nanofibers was around 8 times that of the La(OH)3 nanocrystal fabricated by precipitation without PAN protection. Moreover, remarkably fast adsorption kinetics and high removal rate were observed toward low concentration phosphate due to the high activity of our materials, which can result in a stringent phosphate-deficient condition to kill microorganisms in water effectively. The present material is also capable of preventing sanitized water from recontamination by bacteria and keeping water biologically stable for drinking. Impressively, stabilized by PAN nanofibers, the La(OH)3 nanorods can be easily separated out after reactions and avoid leaking into water. The present development has great potential as a promising antimicrobial solution for practical drinking water security and treatment with a negligible environmental footprint.
The occurrence and mass development of macroinvertebrates in drinking water networks is a challenge for drinking water pipe management. A current problem is the development of larvae of the ...chironomid Paratanytarsus grimmii (mosquito), a so-called pest organism that can have severe impacts on water quality due to mass accumulation from parthenogenic reproduction, biofouling and other aesthetic reasons. The aim of this study was to develop a new practical method for determining larvae size classes and analyzing the growth of the larvae. Knowledge of the dimensions, life cycle and fertility of these larvae within drinking water networks is essential for any risk analysis and the development of P. grimmii pest-control strategies. A two-year study of P. grimmii in a drinking water distribution system in Northern Germany was conducted, and P. grimmii population dynamics are presented. The parthenogenetic reproduction of P. grimmii without any pharate females (facultative flying stage) within the drinking water distribution system was proofed. In 2020 and 2021, five generations of P. grimmii were observed per year, with a maximum abundance of 6350 ind. msup.−3. Mass accumulation occurred in the late-summer/autumn period.
This article reviews perfluoroalkyl and polyfluoroalkyl substance (PFAS) characteristics, their occurrence in surface water, and their fate in drinking water treatment processes. PFASs have been ...detected globally in the aquatic environment including drinking water at trace concentrations and due, in part, to their persistence in human tissue some are being investigated for regulation. They are aliphatic compounds containing saturated carbon–fluorine bonds and are resistant to chemical, physical, and biological degradation. Functional groups, carbon chain length, and hydrophilicity/hydrophobicity are some of the important structural properties of PFASs that affect their fate during drinking water treatment. Full-scale drinking water treatment plant occurrence data indicate that PFASs, if present in raw water, are not substantially removed by most drinking water treatment processes including coagulation, flocculation, sedimentation, filtration, biofiltration, oxidation (chlorination, ozonation, AOPs), UV irradiation, and low pressure membranes. Early observations suggest that activated carbon adsorption, ion exchange, and high pressure membrane filtration may be effective in controlling these contaminants. However, branched isomers and the increasingly used shorter chain PFAS replacement products may be problematic as it pertains to the accurate assessment of PFAS behaviour through drinking water treatment processes since only limited information is available for these PFASs.
Reported removal of PFOA at full-scale drinking water treatment plants. Display omitted
•Full-scale data indicate that conventional drinking water processes fail to remove PFASs.•Chlorination, ozonation, advanced oxidation processes ineffective for PFAS removal.•Granular activated carbon will remove PFASs but may need frequent reactivation.•NF/RO will achieve high rejections except for some low molecular weight PFASs.•Ion exchange promising but less frequently used for drinking water treatment.
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