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Public Health Mar 2024Nitrate is a probable carcinogen regulated in drinking water by the US Environmental Protection Agency (EPA) to a maximum contaminant level (MCL) of 10 mg/L...
OBJECTIVES
Nitrate is a probable carcinogen regulated in drinking water by the US Environmental Protection Agency (EPA) to a maximum contaminant level (MCL) of 10 mg/L nitrate-nitrogen (NO-N; equivalent to 44.3 mg/L NO). We aimed to determine the association of US drinking water nitrate levels with overall as well as cardiovascular, cancer, and other cause mortality.
STUDY DESIGN
This study used a population-based retrospective cohort design.
METHODS
We analyzed data from 2029 participants of the 2005-2006 National Health and Nutrition Examination Survey followed for mortality until 2019 for a median of 13.9 years. We used Cox proportional hazards regression to estimate the hazard ratio (HR) and 95% confidence interval (CI) for mortality associated with drinking water nitrate, adjusting for covariates that included socio-economic factors and pack-years of cigarette smoking.
RESULTS
Drinking water nitrate was detected in 50.8 % of the samples, had a median concentration of 0.77 mg/L NO, and was above US EPA MCL in 0.4 % of participants. In adjusted analysis, drinking water nitrate detection was associated with 73 % higher cancer mortality (HR: 1.73, 95% CI: 1.19-2.51), whereas a 10-fold increase in drinking water nitrate levels was associated with 69 % higher cancer mortality (HR: 1.69, 95% CI: 1.24-2.31) and 21 % higher overall mortality (HR: 1.21, 95% CI: 1.00-1.46). Drinking water nitrate below EPA MCL was still associated with higher cancer mortality (HR: 1.61, 95% CI: 1.07-2.43 per 10-fold increase and HR: 1.61, 95% CI: 1.08-2.42 for detection).
CONCLUSIONS
Levels of drinking water nitrate may be an overlooked contributor to cancer mortality in the United States.
Topics: United States; Humans; Nitrates; Drinking Water; Nutrition Surveys; Retrospective Studies; Neoplasms
PubMed: 38330736
DOI: 10.1016/j.puhe.2024.01.001 -
Environmental Monitoring and Assessment Jul 2024Fluvial sediment analysis and water quality assessment are useful to identify anthropic and natural sources of pollution in rivers. Currently, there is a lack of...
Fluvial sediment analysis and water quality assessment are useful to identify anthropic and natural sources of pollution in rivers. Currently, there is a lack of information about water quality in the Pixquiac basin (Veracruz state, Mexico), and this scarcity of data prevents authorities to take adequate measures to protect water resources. The basin is a crucial territory for Xalapa, the capital city of Veracruz state, as it gets 39% of its drinkable water from it. This research analyzed 10 physicochemical parameters and 12 metal concentrations in various rivers and sources during two seasons. Dissolved metals presented average concentrations (µg/L): Al (456.25) > Fe (199.4) > Mn (16.86) > Ba (13.8) > Zn (7.6) > Cu (1.03) > Pb (0.27) > As (0.12) > Ni (0.118) (Cd, Cr and Hg undetectable). Metals in sediment recorded average concentrations (ppm): Fe (38575) > Al (38425) > Mn (460) > Ba (206.2) > Zn (65.1) > Cr (29.8) > Ni (20.9) > Cu (16.4) > Pb (4.8) > As (2.1) (Cd and Hg undetectable). During the rainy season, Water Quality Index (WAWQI) classified stations P17 and P18's water as "unsuitable for drinking" with values of 110.4 and 117.6. Enrichment factor (EF) recorded a "moderate enrichment" of Pb in sediment in P24. Pollution was mainly explained by wastewater discharges in rivers but also because of erosion and rainfall events. Statistical analysis presented strong relationships between trace and major metals which could explain a common natural origin for metals in water and sediment: rock lixiviation.
Topics: Mexico; Water Pollutants, Chemical; Environmental Monitoring; Geologic Sediments; Water Quality; Drinking Water; Water Supply; Rivers; Metals, Heavy; Metals
PubMed: 38958826
DOI: 10.1007/s10661-024-12841-6 -
Environmental Science & Technology Sep 2023With the increase of algal blooms worldwide, drinking water resources are threatened by the release of various algal toxins, which can be hepatotoxic, cytotoxic, or... (Review)
Review
With the increase of algal blooms worldwide, drinking water resources are threatened by the release of various algal toxins, which can be hepatotoxic, cytotoxic, or neurotoxic. Because of their ubiquitous occurrence in global waters and incomplete removal in conventional drinking water treatment, oxidation/disinfection processes have become promising alternative treatment options to destroy both the structures and toxicity of algal toxins. This Review first summarizes the occurrence and regulation of algal toxins in source water and drinking water. Then, the transformation kinetics, disinfection byproducts (DBPs)/transformation products (TPs), pathways, and toxicity of algal toxins in water oxidation/disinfection processes, including treatment by ozonation, chlorination, chloramination, ultraviolet-based advanced oxidation process, and permanganate, are reviewed. For most algal toxins, hydroxyl radicals (HO) exhibit the highest oxidation rate, followed by ozone and free chlorine. Under practical applications, ozone and chlorine can degrade most algal toxins to meet water quality standards. However, the transformation of the parent structures of algal toxins by oxidation/disinfection processes does not guarantee a reduction in toxicity, and the formation of toxic TPs should also be considered, especially during chlorination. Notably, the toxicity variation of algal toxins is associated with the chemical moiety responsible for toxicity (e.g., Adda moiety in microcystin-LR and uracil moiety in cylindrospermopsin). Moreover, the formation of known halogenated DBPs after chlorination indicates that toxicity in drinking water may shift from toxicity contributed by algal toxins to toxicity contributed by DBPs. To achieve the simultaneous toxicity reduction of algal toxins and their TPs, optimized oxidation/disinfection processes are warranted in future research, not only for meeting water quality standards but also for effective reduction of toxicity of algal toxins.
Topics: Drinking Water; Chlorine; Disinfection; Oxidation-Reduction; Halogenation; Chlorides
PubMed: 37603687
DOI: 10.1021/acs.est.3c01912 -
Water Research Aug 2023The vast majority of residents of high-income countries (≥90%) reportedly have high access to safely managed drinking water. Owing perhaps to the widely held... (Review)
Review
The vast majority of residents of high-income countries (≥90%) reportedly have high access to safely managed drinking water. Owing perhaps to the widely held perception of near universal access to high-quality water services in these countries, the burden of waterborne disease in these contexts is understudied. This systematic review aimed to: identify population-scale estimates of waterborne disease in countries with high access to safely managed drinking water, compare methods to quantify disease burden, and identify gaps in available burden estimates. We conducted a systematic review of population-scale disease burden estimates attributed to drinking water in countries where ≥90% of the population has access to safely managed drinking water per official United Nations monitoring. We identified 24 studies reporting estimates for disease burden attributable to microbial contaminants. Across these studies, the median burden of gastrointestinal illness risks attributed to drinking water was ∼2,720 annual cases per 100,000 population. Beyond exposure to infectious agents, we identified 10 studies reporting disease burden-predominantly, cancer risks-associated with chemical contaminants. Across these studies, the median excess cancer cases attributable to drinking water was 1.2 annual cancer cases per 100,000 population. These median estimates slightly exceed WHO-recommended normative targets for disease burden attributable to drinking water and these results highlight that there remains important preventable disease burden in these contexts, particularly among marginalized populations. However, the available literature was scant and limited in geographic scope, disease outcomes, range of microbial and chemical contaminants, and inclusion of subpopulations (rural, low-income communities; Indigenous or Aboriginal peoples; and populations marginalized due to discrimination by race, ethnicity, or socioeconomic status) that could most benefit from water infrastructure investments. Studies quantifying drinking water-associated disease burden in countries with reportedly high access to safe drinking water, focusing on specific subpopulations lacking access to safe water supplies and promoting environmental justice, are needed.
Topics: Humans; Drinking Water; Waterborne Diseases; Water Pollution; Water Supply; Cost of Illness; Neoplasms
PubMed: 37390656
DOI: 10.1016/j.watres.2023.120244 -
Journal of Hazardous Materials Sep 2023Microorganisms play an important role in the degradation of pollutants. However, they also cause problems in drinking water distribution systems, such as pipe corrosion...
Migration of rare and abundant species, assembly mechanisms, and ecological networks of microbiomes in drinking water treatment plants: Effects of different treatment processes.
Microorganisms play an important role in the degradation of pollutants. However, they also cause problems in drinking water distribution systems, such as pipe corrosion and biofilm growth. The microbial assembly mechanisms and molecular ecological networks associated with different drinking water treatment processes have not yet been clearly analyzed. Therefore, this study investigated the microbiomes of three processes (coal filtration-activated carbon, ozone-activated carbon and UV, and ozone-activated carbon) during different seasons. The results showed that the microbial composition and diversity among the different processes and during different seasons. Water treatment processes had deterministic effects on the microbial assembly process and significantly changed the composition of rare and abundant species, altering the size and modules of molecular ecology networks. Rare species considered as keystone species play important roles in microbial ecology and microbial community construction. Ozone-activated carbon and UV/chlorination decreased the bacterial concentration, increased the deterministic process of microbial assembly, and significantly reduced the size of the network, which is of great significance to microbial control in drinking water. This research broadens our perspectives on the microbial assembly associated with drinking water treatment processes and contributes to ensuring the safe supply of drinking water.
Topics: Drinking Water; Charcoal; Water Purification; Microbiota; Ozone
PubMed: 37257378
DOI: 10.1016/j.jhazmat.2023.131726 -
International Journal of Hygiene and... Jul 2024In the US, violations of drinking water regulations are highest in lower-income rural areas overall, and particularly in Central Appalachia. However, data on drinking...
OBJECTIVES
In the US, violations of drinking water regulations are highest in lower-income rural areas overall, and particularly in Central Appalachia. However, data on drinking water use, quality, and associated health outcomes in rural Appalachia are limited. We sought to assess public and private drinking water sources and associated risk factors for waterborne pathogen exposures for individuals living in rural regions of Appalachian Virginia.
METHODS
We administered surveys and collected tap water, bottled water, and saliva samples in lower-income households in two adjacent rural counties in southwest Virginia (bordering Kentucky and Tennessee). Water samples were tested for pH, temperature, conductivity, total coliforms, E. coli, free chlorine, nitrate, fluoride, heavy metals, and specific pathogen targets. Saliva samples were analyzed for antibody responses to potentially waterborne infections. We also shared water analysis results with households.
RESULTS
We enrolled 33 households (83 individuals), 82% (n = 27) with utility-supplied water and 18% with private wells (n = 3) or springs (n = 3). 58% (n = 19) reported household incomes of <$20,000/year. Total coliforms were detected in water samples from 33% (n = 11) of homes, E. coli in 12%, all with wells or springs (n = 4), and Aeromonas, Campylobacter, and Enterobacter in 9%, all spring water (n = 3). Diarrhea was reported for 10% of individuals (n = 8), but was not associated with E. coli detection. 34% (n = 15) of saliva samples had detectable antibody responses for Cryptosporidium spp., C. jejuni, and Hepatitis E. After controlling for covariates and clustering, individuals in households with septic systems and straight pipes had significantly higher likelihoods of antibody detection (risk ratios = 3.28, 95%CI = 1.01-10.65).
CONCLUSIONS
To our knowledge, this is the first study to collect and analyze drinking water samples, saliva samples, and reported health outcome data from low-income households in Central Appalachia. Our findings indicate that utility-supplied water in this region was generally safe, and individuals in low-income households without utility-supplied water or sewerage have higher exposures to waterborne pathogens.
Topics: Humans; Drinking Water; Virginia; Male; Adult; Female; Middle Aged; Saliva; Water Microbiology; Water Quality; Water Supply; Young Adult; Adolescent; Rural Population; Aged; Appalachian Region; Child; Poverty
PubMed: 38772087
DOI: 10.1016/j.ijheh.2024.114390 -
Journal of Water and Health Nov 2023This article compares the concentration levels of 17β-estradiol (E2), bisphenol-A (BPA) and caffeine (CAF) in the Sinos River, Brazil, which is a source of drinking...
This article compares the concentration levels of 17β-estradiol (E2), bisphenol-A (BPA) and caffeine (CAF) in the Sinos River, Brazil, which is a source of drinking water and the presence of contaminants after the conventional treatment in a municipal water treatment plant (WTP). A total of nine sampling campaigns were carried out, with sample collection in the Sinos River, upstream and downstream of the WTP, in addition to a drinking water sample (DW). The samples were extracted with solid phase extraction (SPE) and the concentration by liquid chromatography coupled to mass spectrometry (LC-MS). The maximum concentration in the Sinos River was 6,127.99 ng·L for E2, 3,294.63 ng·L for BPA and 1,221.95 ng·L for CAF. In drinking water, the concentration range of E2, BPA and CAF was from less than the Detection Limit (DL) up to 437.50 ng·L,
- water source. Drinking water indicates the need for a new treatment process that could promote the removal of these compounds.
Topics: Caffeine; Drinking Water; Estradiol; Water Purification
PubMed: 38017601
DOI: 10.2166/wh.2023.234 -
The Science of the Total Environment Oct 2023Disaggregated information on welfare indicators is useful for targeted policies. This study constructs geographic maps of water, sanitation, and hygiene (WASH) for...
Disaggregated information on welfare indicators is useful for targeted policies. This study constructs geographic maps of water, sanitation, and hygiene (WASH) for provinces and districts in Vietnam (which has 63 provinces and 712 districts). The study finds that poorer provinces and districts tend to have remarkably lower access to safely managed sanitation and water. Provinces in the Northern Midlands and Mountain Areas, and Central Highlands have the lowest level of access to safely managed sanitation and drinking water. There is a great variation in the availability of WASH facilities between districts within the same provinces. Additionally, the study highlights that districts with a higher population of ethnic minorities tend to experience lower rates of access to safely managed sanitation and drinking water. Even within the same district, moreover, ethnic minorities face greater challenges in accessing safely managed sanitation and drinking water compared to the majority Kinh population.
Topics: Drinking Water; Water Supply; Sanitation; Hygiene; Policy
PubMed: 37406684
DOI: 10.1016/j.scitotenv.2023.165277 -
Chemosphere Sep 2023The interaction between microplastics (MPs) and microorganisms may alter the distribution of antibiotic resistance genes (ARGs) in water and increase the ecological risk...
The interaction between microplastics (MPs) and microorganisms may alter the distribution of antibiotic resistance genes (ARGs) in water and increase the ecological risk of drinking water sources. To investigate the characteristics of MPs geographical distribution and its potential ecological risk in typical urban water, this study was conducted in Zhushan Bay, and we carried out a combination of tests to analyze the distribution of MPs and the migration changes of their surface microbial community composition and ARGs in different media by 16S rRNA gene high-throughput sequencing, non-targeted metabolomics and qPCR genomics in the near-shore (I), middle area (Ⅱ) and near-lake (Ⅲ) of Zhushan Bay. The results showed that MPs in fibrous form were dominant in the aquatic environment of Zhushan Bay; Polyurethane (PU) and Silicone were the main MPs types in Zhushan Bay. The abundance of MPs in the water of Zhushan Bay was winter > summer > autumn > spring; and in the sediment was winter > summer > autumn > spring, respectively. The distribution results of MPs in geographical location are as follows: In the water I > Ⅱ > Ⅲ, sediment exhibited Ⅱ > Ⅲ > I. The results indicate that physicochemical factors will affect the geographical distribution of MPs and their surface microbial community composition in the aquatic environment of Zhushan Bay. More cooperative behaviors and increased metabolically important pathways occurred in the microbial network on water-MPs compared to sediment-MPs. However, the microbial community in the sediment-MPs was more stable and had higher abundance of mobile genetic elements (MGEs). A total of 362 differential metabolites were detected, of which 193 were up-regulated and 19 down-regulated differential metabolites. blaTEM, Sul, and inti1 were prevalent in both the water and sediments of Zhushan Bay. Sul1 was most contaminated in ARGs. This study provides the latest field data and insights into MPs pollution in key aquatic environments.
Topics: Microplastics; Plastics; Bays; RNA, Ribosomal, 16S; Drinking Water; Genes, Bacterial; China; Anti-Bacterial Agents
PubMed: 37247671
DOI: 10.1016/j.chemosphere.2023.139024 -
Environmental Science and Pollution... Mar 2024Water quality, increasingly recognized for its significant impact on health, is garnering heightened attention. Previous studies were limited by the number of water...
Assessment of drinking water quality and health risk using water quality index and multiple computational models: a case study of Yangtze River in suburban areas of Wuhan, central China, from 2016 to 2021.
Water quality, increasingly recognized for its significant impact on health, is garnering heightened attention. Previous studies were limited by the number of water quality indicators and the duration of analysis. This study assessed the drinking water quality and its associated health risk in suburban areas of Wuhan, a city in central China, from 2016 to 2021. We collected 368 finished water samples and 1090 tap water samples and tested these for 37 different indicators. The water quality was evaluated using the water quality index, with trends over time analyzed via the Mann-Kendall test. Furthermore, an artificial neural network model was employed for future water quality prediction. Our findings indicated that the water quality in rural Wuhan was generally good and had an improvement from 2016 to 2021. The qualification and excellent rates were 98.91% and 86.81% for finished water, and 97.89% and 78.07% for tap water, respectively. The drinking water quality was predicted to maintain satisfactory in 2022 and 2023. Additionally, principal component analysis revealed that the primary sanitary issues in the water were poor sensory properties, elevated metal contents, high levels of dissolved solids, and microbial contamination. These issues were likely attributable to domestic and industrial waste discharge and aging water pipelines. The health risks associated with the long-term consumption of this water have been steadily decreasing over the years, underscoring the effectiveness of Wuhan's ongoing water management efforts.
Topics: Water Quality; Drinking Water; Water Pollutants, Chemical; Rivers; China; Environmental Monitoring; Risk Assessment
PubMed: 38413522
DOI: 10.1007/s11356-024-32187-3