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Journal of Hazardous Materials Jan 2024Halogenated benzoquinones (HBQs) are frequently detected in tap water. HBQ levels are correlated with water age. As the water-transmission distance (water age)...
Halogenated benzoquinones (HBQs) are frequently detected in tap water. HBQ levels are correlated with water age. As the water-transmission distance (water age) increases, the levels of bromo-benzoquinones (Br-BQs) decreased and those of chloro-benzoquinones (Cl-BQs) remained relatively stable in drinking water-distribution system in the presence of residual chlorine. 2,3,5,6-Tetrachloro-1,4-benzoquinone (TCBQ) and 2,6-dibromo-1,4-benzoquinone (DBBQ) were the most abundant Cl-BQ and Br-BQ, with maximum concentrations of 60.2 and 181.4 ng/L, respectively. TCBQ and DBBQ were chosen as representatives of HBQs to investigate their reactions with chlorine, including kinetics, pathways, and changes in toxicity. The hydrolysis and chlorination rates of HBQs were significantly pH-dependent, and the kinetic rates of DBBQ were faster than TCBQ in the pH range of 5-10. Chlorination converted highly toxic TCBQ and DBBQ to less-toxic chlorinated/brominated aliphatic disinfection by-products (DBPs), thereby reducing the overall toxicity of water bodies. This study provides comprehensive insights into the distinct life cycles of TCBQ and DBBQ in drinking water, covering formation, transformation, and toxicity. These findings provide a nuanced understanding of the risks posed by HBQs at various locations within the drinking water distribution system, offering valuable guidance for improving the control of DBPs in drinking water.
Topics: Drinking Water; Chlorine; Disinfection; Halogens; Halogenation; Benzoquinones; Water Pollutants, Chemical; Water Purification; Disinfectants
PubMed: 37801978
DOI: 10.1016/j.jhazmat.2023.132692 -
Environmental Research Dec 2023Groundwater (GW) is a precious resource for human beings as we depend on it as a source of fresh drinking water, agricultural practices, industrial and domestic uses,...
Groundwater (GW) is a precious resource for human beings as we depend on it as a source of fresh drinking water, agricultural practices, industrial and domestic uses, etc. Extreme exposure of arsenic (As) and fluoride (F-) concentrations along the coastal GW aquifers of "South 24 Parganas and East Medinipur" diluted the quality of GW and created serious health issues. Various chronic health disorders such as - black foot disease, fluorosis skin cancer, cardiac problems, and other water borne diseases have been noticed in these two coastal districts. The comprehensive entropy-weighted water quality index (EWQI) and health risk assessment (HRA) were applied to evaluate the quality of GW and probable health risks in the coastal districts. Monte Carlo simulation and sensitivity analysis methods were simultaneously adopted to identify the non-carcinogenic health risk assessment due to regular ingestion of contaminated GW. As the study region is densely populated and part of the Sundarbans Ramsar site, it has greater importance at the international level along with regional importance to address the GWQ of this region. The major findings of the present study highlight that almost 55% of the study area is confronting serious GW quality issues and associated probable health risk (HR) due to the intense accumulation of As and F- in the GW aquifers of the study area. Children's health is more vulnerable due to the consumption of As containing GW, and adults are highly affected due to the intake of F- bearing GW in the coastal districts. The findings of the current study will draw the attention of hydrologists, groundwater management authorities, government bodies, and NGOs to regulate and monitor the GW aquifers routinely, enhance GW quality, minimizing the health hazards and sustainable water management in a more scientific and sustainable way which must be advantageous for coastal people.
Topics: Child; Adult; Humans; Fluorides; Drinking Water; Arsenic; Environmental Monitoring; Water Pollutants, Chemical; Groundwater; Water Quality; Risk Assessment
PubMed: 37775015
DOI: 10.1016/j.envres.2023.117257 -
Journal of Environmental Sciences... Jul 2023Reservoirs have been served as the major source of drinking water for dozens of years. The water quality safety of large and medium reservoirs increasingly becomes the...
Reservoirs have been served as the major source of drinking water for dozens of years. The water quality safety of large and medium reservoirs increasingly becomes the focus of public concern. Field test has proved that water-lifting and aeration system (WLAS) is a piece of effective equipment for in situ control and improvement of water quality. However, its intrinsic bioremediation mechanism, especially for nitrogen removal, still lacks in-depth investigation. Hence, the dynamic changes in water quality parameters, carbon source metabolism, species compositions and co-occurrence patterns of microbial communities were systematically studied in Jinpen Reservoir within a whole WLAS running cycle. The WLAS operation could efficiently reduce organic carbon (19.77%), nitrogen (21.55%) and phosphorus (65.60%), respectively. Biolog analysis revealed that the microbial metabolic capacities were enhanced via WLAS operation, especially in bottom water. High-throughput sequencing demonstrated that WLAS operation altered the diversity and distributions of microbial communities in the source water. The most dominant genus accountable for aerobic denitrification was identified as Dechloromonas. Furthermore, network analysis revealed that microorganisms interacted more closely through WLAS operation. Oxidation-reduction potential (ORP) and total nitrogen (TN) were regarded as the two main physicochemical parameters influencing microbial community structures, as confirmed by redundancy analysis (RDA) and Mantel test. Overall, the results will provide a scientific basis and an effective way for strengthening the in-situ bioremediation of micro-polluted source water.
Topics: Water Quality; Drinking Water; Lifting; Nitrogen; Carbon; Denitrification
PubMed: 36804234
DOI: 10.1016/j.jes.2022.09.006 -
Journal of Water and Health Jun 2024Diarrhoea is one of the major waterborne diseases spread through the faecal-oral route causing over 10 million cases and over 1,000 deaths per year in India. This study...
Diarrhoea is one of the major waterborne diseases spread through the faecal-oral route causing over 10 million cases and over 1,000 deaths per year in India. This study critically evaluates the interlinkage between bacteriological water quality, i.e. faecal coliforms and diarrhoea cases for the three pre-pandemic years 2017, 2018 and 2019 based on multiple sources. With around 17% of households tap water connectivity as of August 2019, the majority of the Indian population depends on raw groundwater (GW) and surface water sources. For this, faecal coliform (FC) levels in surface and GW have been mapped at district levels using data from India's National Water Quality Monitoring Programme. Health Management Information System's data on diarrhoea have been used to understand the monthly and district-wise variation of diarrhoea. The trends of FC, diarrhoea inpatient cases, and diarrhoea inpatient rates have been discussed. The analysis showed issues associated with the reliability and usefulness of these datasets with 43% of total India districts with no reported FC values for the study period. This study reveals a clear gap in the interlinkage between diarrhoea and bacteriological water quality with the unavailability of granular water quality data as a major challenge.
Topics: Diarrhea; India; Drinking Water; Humans; Water Microbiology; Feces; Water Quality; Enterobacteriaceae; Water Supply
PubMed: 38935461
DOI: 10.2166/wh.2024.109 -
Neurotoxicology and Teratology 2023Fluoride (F) exposure in drinking water may lead to reduced cognitive function among children; however, findings largely remain inconclusive. In this pilot study, we...
Fluoride (F) exposure in drinking water may lead to reduced cognitive function among children; however, findings largely remain inconclusive. In this pilot study, we examined associations between a range of chronic F exposures (low to high: 0.4 to 15.5 mg/L) in drinking water and cognition in school-aged children (5-14 years, n = 74) in rural Ethiopia. Fluoride exposure was determined from samples of community-based drinking water wells and urine. Cognitive performance was measured using: 1) assessments of ability to draw familiar objects (donkey, house, and person), and 2) a validated Cambridge Neuropsychological Test Automated Battery's (CANTAB) Paired Associate Learning (PAL), which examines memory and new learning and is closely associated with hippocampus function of the brain. Associations between F and cognitive outcomes were evaluated using regression analysis, adjusting for demographic, health status, and other covariates. The median (range) of water and urine F levels was 7.6 (0.4-15.5 mg/L) and 6.3 (0.5-15.7 mg/L), respectively; these measures were strongly correlated (r = 0.74), indicating that water is the primary source of F exposure. Fluoride in drinking water was negatively associated with cognitive function, measured by both drawing and CANTAB test performance. Inverse relationships were also found between F and drawing objects task scores, after adjusting for covariates (p < 0.05). Further analysis using CANTAB PAL tasks in the children confirmed that F level in drinking water was positively associated with the number of errors made by children (p < 0.01), also after adjusting for covariates (p < 0.05). This association between water F and total errors made became markedly stronger as PAL task difficulty increased. Fluoride exposure was also inversely associated with other PAL tasksthe number of patterns reached, first attempt memory score and mean errors to success. These findings provide supportive evidence that high F exposures may be associated with cognitive deficits in children. Additional well-designed studies are critically needed to establish the neurotoxicity of F in children and adults exposed to both low levels known to protect dental caries, as well as excess F levels in drinking water.
Topics: Humans; Child; Fluorides; Drinking Water; Pilot Projects; Dental Caries; Cognition
PubMed: 37690675
DOI: 10.1016/j.ntt.2023.107293 -
Environmental Research Sep 2023Arsenic (As) is one of the most dangerous substances that can affect human health and long-term exposure to As in drinking water can even cause cancer. The objective of...
Arsenic (As) is one of the most dangerous substances that can affect human health and long-term exposure to As in drinking water can even cause cancer. The objective of this study was to investigate the concentrations of total As in the blood of inhabitants of a Colombian region impacted by gold mining and to evaluate its genotoxic effect through DNA damage by means of the comet assay. Additionally, the concentration of As in the water consumed by the population as well as the mutagenic activity of drinking water (n = 34) in individuals were determined by hydride generator atomic absorption spectrometry and the Ames test, respectively. In the monitoring, the study population was made up of a group of 112 people, including inhabitants of four municipalities: Guaranda, Sucre, Majagual, and San Marcos from the Mojana region as the exposed group, and Montería as a control group. The results showed DNA damage related to the presence of As in blood (p < 0.05) in the exposed population, and blood As concentrations were above the maximum allowable limit of 1 μg/L established by the ATSDR. A mutagenic activity of the drinking water was observed, and regarding the concentrations of As in water, only one sample exceeded the maximum permissible value of 10 μg/L established by the WHO. The intake of water and/or food containing As is potentially generating DNA damage in the inhabitants of the Mojana region, which requires surveillance and control by health entities to mitigate these effects.
Topics: Humans; Arsenic; Gold; Mutagens; Drinking Water; Colombia; Water Pollutants, Chemical; DNA Damage; Mining
PubMed: 37236386
DOI: 10.1016/j.envres.2023.116229 -
Environmental Pollution (Barking, Essex... May 2024Microplastics in drinking water captured widespread attention following reports of widespread detection around the world. Concerns have been raised about the potential... (Review)
Review
Microplastics in drinking water captured widespread attention following reports of widespread detection around the world. Concerns have been raised about the potential adverse effects of microplastics in drinking water on human health. Given the widespread interest in this research topic, there is an urgent need to compile existing data and assess current knowledge. This paper provides a systematic review of studies on microplastics in drinking water, their evidence, key findings, knowledge gaps, and research needs. The data collected show that microplastics are widespread in drinking water, with large variations in reported concentrations. Standardized methodologies of sampling and analysis are urgently needed. There were more fibrous and fragmented microplastics, with the majority being <10 μm in size and composed of polyester, polyethylene, polypropylene, and polystyrene. Little attention has been paid to the color of microplastics. More research is needed to understand the occurrence and transfer of microplastics throughout the water supply chain and the treatment efficiency of drinking water treatment plants (DWTPs). Methods capable of analyzing microplastics <10 μm and nanoplastics are urgently needed. Potential ecological assessment models for microplastics currently in use need to be improved to take into account the complexity and specificity of microplastics.
Topics: Humans; Microplastics; Plastics; Drinking Water; Water Pollutants, Chemical; Environmental Monitoring
PubMed: 38537794
DOI: 10.1016/j.envpol.2024.123857 -
Water Research Sep 2023Discoloured drinking water, caused by elevated concentrations of organic and inorganic particles, is unacceptable. It occurs due to accumulation and subsequent... (Review)
Review
Discoloured drinking water, caused by elevated concentrations of organic and inorganic particles, is unacceptable. It occurs due to accumulation and subsequent mobilisation of material from within drinking water distribution infrastructure. Discolouration is currently partially explained by either the theories of cohesive layers or gravitational sedimentation. It is proposed and shown here how the processes behind these two theories both occur and how to integrate them to better explain observed behaviour and inform operational interventions to reduce discolouration. Deficiencies in understanding regarding the process and factors that influence material accumulation are highlighted. Future research addressing these deficiencies will enable determination of long term sustainable management strategies balancing capital investment and operational maintenance to safeguard distribution of high quality drinking water.
Topics: Drinking Water; Water Supply; Water Quality
PubMed: 37516082
DOI: 10.1016/j.watres.2023.120416 -
Science & Justice : Journal of the... Nov 2023Forensic anthropologists have used oxygen isotopic analyses (δO) in recent decades because of its ability to help estimate probable regions of origin of unidentified...
Forensic anthropologists have used oxygen isotopic analyses (δO) in recent decades because of its ability to help estimate probable regions of origin of unidentified individuals based on isotopic composition of bodily tissues. Prior research has found that drinking water is geographically patterned and that tap water is often representative of drinking water in assessing these links between human tissues and geography. Researchers have begun applying the method in a variety of global contexts. This research critically assesses the assumption that tap water is isotopically representative of drinking water in Oaxaca, Mexico. Drinking water samples from Oaxaca were analyzed and compared with predicted δO values from a previously constructed tap water isoscape of Mexico. Hair samples from Oaxaca were also analyzed to compare against various water sources. Tap water δO values do not reliably reflect drinking water δO in sampled regions of Oaxaca, Mexico. Further, the models relating hair keratin to drinking water, built on this assumption, fail to hold predictive power. With an incomplete understanding of tap water's ability to represent drinking water isotopically, researchers need to study the role of other key factors in δO values. If the individual's being identified with δO are from non-Western communities, forensic practitioners run the risk of incorrectly predicting region of origin because of the method's assumptions. Recognizing the varying sociocultural realities of the communities forensic practitioners seek to aid is paramount as we grow and develop our methods moving forward.
Topics: Humans; Oxygen Isotopes; Drinking Water; Mexico; Forensic Medicine; Geography
PubMed: 38030344
DOI: 10.1016/j.scijus.2023.10.001 -
Journal of Water and Health Jul 2023Legionella concentrations in drinking water have been regulated for decades and are evaluated with regard to their concentrations in drinking water plumbing systems...
Legionella concentrations in drinking water have been regulated for decades and are evaluated with regard to their concentrations in drinking water plumbing systems (DWPS). The respective action levels differ at the international level. In Germany, the Federal Environment Agency (UBA) specifies the application of ISO 11731 for the detection of legionella in drinking water and gives a binding recommendation for the methods to be used for culturing and evaluation. Effective from 01 March 2019, the UBA recommendation was revised. The utilized culture media in the culture approach were altered, consequently affecting the spectrum of legionella colonies detected in drinking water. Using data from a routine legionella monitoring of a large laboratory, over a period of 6 years and 17,270 individual drinking water samples, allowed us to assess the impact of the alteration on the assessment of DWPS. By comparing the amount of action level exceedances before and after the method change, it could be demonstrated that exceedances are reported significantly more often under the new method. Consequently, the corresponding action level for evaluation of legionella contamination and the resulting risk to human health needs to be revised to avoid the misleading impression of increased health risk.
Topics: Humans; Legionella; Drinking Water; Water Microbiology; Sanitary Engineering; Germany; Water Supply; Legionella pneumophila
PubMed: 37515560
DOI: 10.2166/wh.2023.035