Nitrate and nitrite contamination in drinking water and cancer risk: A systematic review with meta-analysis

A systematic review of strategies to overcome barrier for nitrate separation systems from drinking water: Focusing on waste streams treatment processes

By 2030, the UN General Assembly issued the Sustainable Development Goal 6, which calls for the provision of safe drinking water. However, water resources are continuously decreasing in quantity and quality. NO3- is the most widespread pollutant worldwide, threatening both human health and ecosystems. NO3- separation systems (NSS) using IX and membrane-based techniques (MBT) are considered practical and efficient technologies, but the management of IX waste brine (IXWB) and concentrate streams for MBT (CSM), as well as the high salt requirements for IX regeneration, are challenging from both economic and environmental perspectives. It is essential to classify the different waste management strategies in order to examine the current state of research and identify the best option to address these issues. This review provides harmonized information on IXWB/CSM management strategies. This study is the first systematic review of all papers available in the Web of Science, Scopus, and PubMed databases published until February 2023. 75% of the studies focused on the use of biological denitrification (BD) and catalytic denitrification (CD). Although innovative technologies (bio-regeneration and direct CD) have advantages over indirect processes, they are not yet practical for large-scale plants because their reliability is unknown. Moreover, the generation of NH4+ is the major challenge for application large-scale of chemical reduction. An innovative work flow diagram, challenges, and future prospects are presented. The review shows that integrating modified NSS with IXWB/CSM treatment is a promising sustainable solution, as the combination could be economically and environmentally beneficial and remove barriers to NNS application.

Determination of Nitric Oxide and Its Metabolites in Biological Tissues Using Ozone-Based Chemiluminescence Detection: A State-of-the-Art Review

Ozone-based chemiluminescence detection (CLD) has been widely applied for determining nitric oxide (•NO) and its derived species in many different fields, such as environmental monitoring and biomedical research. In humans and animals, CLD has been applied to determine exhaled •NO and •NO metabolites in plasma and tissues. The main advantages of CLD are high sensitivity and selectivity for quantitative analysis in a wide dynamic range. Combining CLD with analytical separation techniques like chromatography allows for the analytes to be quantified with less disturbance from matrix components or impurities. Sampling techniques like microdialysis and flow injection analysis may be coupled to CLD with the possibility of real-time monitoring of •NO. However, details and precautions in experimental practice need to be addressed and clarified to avoid wrong estimations. Therefore, using CLD as a detection tool requires a deep understanding of the sample preparation procedure and chemical reactions used for liberating •NO from its derived species. In this review, we discuss the advantages and pitfalls of CLD for determining •NO species, list the different applications and combinations with other analytical techniques, and provide general practical notes for sample preparation. These guidelines are designed to assist researchers in comprehending CLD data and in selecting the most appropriate method for measuring •NO species.

Pd/Cu bimetallic nano-catalyst supported on anion exchange resin (A520E) for nitrate removal from water: High property and stability

High nitrate concentration in water can lead to eutrophication and the disruption of healthy aquatic ecosystems. Additionally, in the human digestive system, it has the potential to be reduced to nitrite, which can be damaging to people's physical health. Catalytic hydrogenation of nitrate is one of the strategies for removing nitrate from water. Using A520E resin as support, we prepared Pd/Cu nano-catalyst (Pd/Cu@A520E) according to a liquid phase reduction method. A520E could improve the transfer process of nitrate in the solution to the activity sites of Pd/Cu nanoparticles, thus increase the reaction rate of nitrate reduction. Pd/Cu bimetallic nano-particles were evenly distributed on/in the resin with a size range from 2 nm to 10 nm. The External Circulating System equipped with Venturi tube (ECSV) was designed to improve the utilization efficiency of H2 in both batch tests and long-term continuous-flow tests. Nearly 100% of nitrate removal efficiency and above 90% of N2 selectivity were achieved in both batch tests and continuous-flow tests. Coexisting Cl- and SO42- at 300 mg/L showed little impact on the property of Pd/Cu@A520E. Pd/Cu@A520E also showed high nitrate removal property and stability in continuous-flow tests of more than 800 h. NO3- was adsorbed onto the active sites (functional groups and Pd/Cu particle sites), meanwhile H2 was adsorbed onto the active sites of Pd/Cu@A520E to form Pd [H]. Then the adsorbed NO3- was reduced into N2 (main product) or NH4+ by Pd [H]. In addition, Pd/Cu@A520E showed high nitrate removal property from municipal waste water.

Dietary Nitrate from Plant Foods: A Conditionally Essential Nutrient for Cardiovascular Health

Under specific conditions, such as catabolic stress or systemic inflammation, endogenous nutrient production becomes insufficient and exogenous supplementation (for example, through dietary intake) is required. Herein, we propose consideration of a dietary nitrate from plant foods as a conditionally essential nutrient for cardiovascular health based on its role in nitric oxide homeostasis. Nitrate derived from plant foods may function as a conditionally essential nutrient, whereas nitrate obtained from other dietary sources, such as drinking water and cured/processed meats, warrants separate consideration because of the associated health risks. We have surveyed the literature and summarized epidemiological evidence regarding the effect of dietary nitrate on cardiovascular disease and risk factors. Meta-analyses and population-based observational studies have consistently demonstrated an inverse association of dietary nitrate with blood pressure and cardiovascular disease outcomes. Considering the available evidence, we suggest 2 different approaches to providing dietary guidance on nitrate from plant-based dietary sources as a nutrient: the Dietary Reference Intakes developed by the National Academies of Sciences, Engineering, and Medicine, and the dietary guidelines evaluated by the Academy of Nutrition and Dietetics. Ultimately, this proposal underscores the need for food-based dietary guidelines to capture the complex and context-dependent relationships between nutrients, particularly dietary nitrate, and health.

Multi-omics Combined with Machine Learning Facilitating the Diagnosis of Gastric Cancer

Gastric cancer (GC) is a highly intricate gastrointestinal malignancy. Early detection of gastric cancer forms the cornerstone of precision medicine. Several studies have been conducted to investigate early biomarkers of gastric cancer using genomics, transcriptomics, proteomics, and metabolomics, respectively. However, endogenous substances associated with various omics are concurrently altered during gastric cancer development. Furthermore, environmental exposures and family history can also induce modifications in endogenous substances. Therefore, in this study, we primarily investigated alterations in DNA mutation, DNA methylation, mRNA, lncRNA, miRNA, circRNA, and protein, as well as glucose, amino acid, nucleotide, and lipid metabolism levels in the context of GC development, employing genomics, transcriptomics, proteomics, and metabolomics. Additionally, we elucidate the impact of exposure factors, including HP, EBV, nitrosamines, smoking, alcohol consumption, and family history, on diagnostic biomarkers of gastric cancer. Lastly, we provide a summary of the application of machine learning in integrating multi-omics data. Thus, this review aims to elucidate: i) the biomarkers of gastric cancer related to genomics, transcriptomics, proteomics, and metabolomics; ii) the influence of environmental exposure and family history on multiomics data; iii) the integrated analysis of multi-omics data using machine learning techniques.

Health-economic valuation of lowering nitrate standards in drinking water related to colorectal cancer in Denmark

Nitrate in drinking water is a contaminant which can affect human health and has been associated with an increased risk of, amongst other diseases, colorectal cancer. Based on epidemiologic data from Denmark on the association between drinking water nitrate and colorectal cancer, the health and economic consequences of lowering the standard of nitrate in drinking water from 50 mg/L to 9.25 mg/L and 3.87 mg/L, respectively are analyzed. The drinking water nitrate attributable number of cases was estimated using the risk in the exposed and unexposed population based on current nationwide exposure distributions. The analysis shows that a lower limit of 9.25 mg/L would decrease the annual number of colorectal cancer cases by 72 (95 % confidence interval: 34-114) and by an additional 55 (95 % CI: 10-100) for a stricter limit of 3.87 mg/L. The resulting avoided health-related costs are $179 million per year for the 9.25 mg/L nitrate limit and another $138 million per year for a further reduction to 3.87 mg/L nitrate. The new requirements would incur costs linked to either i) changes in land use management, ii) well reallocation or iii) use of treatment technologies. The additional costs are estimated to $0.03-1.84 per m3 abstracted water from public water companies, which together with costs for owners of private wells, will result in an average additional cost of $9 and $6 million per year for the two levels. The economic health benefits are higher than the costs for both limits with net gains of $170 million (9.25 mg/L) and additionally $132 million (3.87 mg/L) a year. Even in a worst-case scenario (lowest health-related benefits and highest mitigation costs), there is a likely economic gain for society from lowering the limit to 9.25 mg/L, but this might not be the case for the lower limit of 3.87 mg/L.

Optimizing Autotrophic Sulfide Oxidation in the Oxygen-Based Membrane Biofilm Reactor to Recover Elemental Sulfur

Biological sulfide oxidation is an efficient means to recover elemental sulfur (S0) as a valuable resource from sulfide-bearing wastewater. This work evaluated the autotrophic sulfide oxidation to S0 in the O2-based membrane biofilm reactor (O2-MBfR). High recovery of S0 (80-90% of influent S) and high sulfide oxidation (∼100%) were simultaneously achieved when the ratio of O2-delivery capacity to sulfide-to S0 surface loading (SL) (O2/S2- → S0 ratio) was around 1.5 (g O2/m2-day/g O2/m2-day). On average, most of the produced S0 was recovered in the MBfR effluent, although the biofilm could be a source or sink for S0. Shallow metagenomic analysis of the biofilm showed that the top sulfide-oxidizing genera present in all stages were Thauera, Thiomonas, Thauera_A, and Pseudomonas. Thiomonas or Pseudomonas was the most important genus in stages that produced almost only S0 (i.e., the O2/S2- → S0 ratio around 1.5 g of the O2/m2-day/g O2/m2-day). With a lower sulfide SL, the S0-producing genes were sqr and fccAB in Thiomonas. With a higher sulfide SL, the S0-producing genes were in the soxABDXYZ system in Pseudomonas. Thus, the biofilm community of the O2-MBfR adapted to different sulfide-to-S0 SLs and corresponding O2-delivery capacities. The results illustrate the potential for S0 recovery using the O2-MBfR.

Nitrate prediction in groundwater of data scarce regions: The futuristic fresh-water management outlook

Nitrate contamination in groundwater poses a significant threat to water quality and public health, especially in regions with limited data availability. This study addresses this challenge by employing machine learning (ML) techniques to predict nitrate (NO3--N) concentrations in Mexico's groundwater. Four ML algorithms-Extreme Gradient Boosting (XGB), Boosted Regression Trees (BRT), Random Forest (RF), and Support Vector Machines (SVM)-were executed to model NO3--N concentrations across the country. Despite data limitations, the ML models achieved robust predictive performances. XGB and BRT algorithms demonstrated superior accuracy (0.80 and 0.78, respectively). Notably, this was achieved using ∼10 times less information than previous large-scale assessments. The novelty lies in the first-ever implementation of the 'Support Points-based Split Approach' during data pre-processing. The models considered initially 68 covariates and identified 13-19 significant predictors of NO3--N concentration spanning from climate, geomorphology, soil, hydrogeology, and human factors. Rainfall, elevation, and slope emerged as key predictors. A validation incorporated nationwide waste disposal sites, yielding an encouraging correlation. Spatial risk mapping unveiled significant pollution hotspots across Mexico. Regions with elevated NO3--N concentrations (>10 mg/L) were identified, particularly in the north-central and northeast parts of the country, associated with agricultural and industrial activities. Approximately 21 million people, accounting for 10 % of Mexico's population, are potentially exposed to elevated NO3--N levels in groundwater. Moreover, the NO3--N hotspots align with reported NO3--N health implications such as gastric and colorectal cancer. This study not only demonstrates the potential of ML in data-scarce regions but also offers actionable insights for policy and management strategies. Our research underscores the urgency of implementing sustainable agricultural practices and comprehensive domestic waste management measures to mitigate NO3--N contamination. Moreover, it advocates for the establishment of effective policies based on real-time monitoring and collaboration among stakeholders.

Metabolomic Signatures of Exposure to Nitrate and Trihalomethanes in Drinking Water and Colorectal Cancer Risk in a Spanish Multicentric Study (MCC-Spain)

We investigated the metabolomic profile associated with exposure to trihalomethanes (THMs) and nitrate in drinking water and with colorectal cancer risk in 296 cases and 295 controls from the Multi Case-Control Spain project. Untargeted metabolomic analysis was conducted in blood samples using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry. A variety of univariate and multivariate association analyses were conducted after data quality control, normalization, and imputation. Linear regression and partial least-squares analyses were conducted for chloroform, brominated THMs, total THMs, and nitrate among controls and for case-control status, together with a N-integration model discriminating colorectal cancer cases from controls through interrogation of correlations between the exposure variables and the metabolomic features. Results revealed a total of 568 metabolomic features associated with at least one water contaminant or colorectal cancer. Annotated metabolites and pathway analysis suggest a number of pathways as potentially involved in the link between exposure to these water contaminants and colorectal cancer, including nicotinamide, cytochrome P-450, and tyrosine metabolism. These findings provide insights into the underlying biological mechanisms and potential biomarkers associated with water contaminant exposure and colorectal cancer risk. Further research in this area is needed to better understand the causal relationship and the public health implications.

Optimum anatase/rutile ratios of TiO2 for photocatalytic denitrification from IX brine waste and real RO concentrate: RSM-CCD model and the use of an economical and efficient hole scavenger study

Both ion exchange (IX) and reverse osmosis (RO) technologies are effective in removing NO3- from drinking water, but the disposal of waste streams and the large amount of salt needed for to prepare fresh brine in IX have become economic and environmental challenges. To overcome these barriers, photocatalytic denitrification (PD) using TiO2 nanoparticles in different anatase/rutile (A/R) ratios was applied to IX brine waste (IXWB) and real RO concentrate (real ROC). The synthesized samples were characterized by XRD, FESEM-EDX, and elemental mapping, BET, and UV-Vis absorption spectra. Experiments design, process optimization, and confirmation of results were performed using CCD-RSM. The study also investigated the use of glycerol, a by-product of biodiesel production, as an economic hole scavenger. The effect of different concentrations of SO4-2 on the removal efficiency of NO3- and the N2 selectivity was also investigated. The anatase phase converts to rutile with increasing calcination temperature, resulting in larger crystallites and particle sizes and narrower optical band gaps of TiO2 nanoparticles. Under optimal conditions, the mixed A (79%)/R (21%) phase of TiO2 with FA showed the highest photoactivity in conversion NO3- (89% and 95%) with N2 selectivity (83% and 85% for IXWB and real ROC, respectively). For real ROC, the use of glycerol as an economical hole scavenger resulted in 100% NO3- reduction. A possible mechanism involving glycerol and FA is discussed. Finally, optimized (A/R) ratios of TiO2 nanoparticles were successfully supported on the surface of GAC (GAC/TiO2). The composite sample can be easily recycled and reused from solution and exhibits high photoactivity even after five cycles.

Modeling, quality assessment, and Sobol sensitivity of water resources and distribution system in Shiraz: A probabilistic human health risk assessment

Given water's vital role in supporting life and ecosystems, global climate change and human activities have significantly diminished its availability and quality. This study explores the health risks of drinking water consumption in the shiraz county water resources and distribution system. The result showed that the water was slightly alkaline. However, the average pH values during the study were within the permissible range. The area's abundance of total hardness and calcium was due to the high concentration of minerals in rocks and soils. The nitrate and fluoride concentrations in drinking groundwater varied from 0.02 to 116.70 mg/L and 0.10-1.85 mg/L, respectively. Although the water quality index indicated that 52.63, 45.03, and 20.3 percent of samples were of excellent, good, and poor quality in 2020, those percentages obtained 46.05, 52.09, and 14.0 percent in 2021. The regression values of training, testing, validation, and the proposed artificial neural network model were 0.93, 0.92, 0.85, and 0.92. The maximum levels of hazard quotient of nitrate and fluoride (except for adults) were higher than 1 in all age groups, indicating a high non-carcinogenic risk by exposure to nitrate. Furthermore, according to the Monte Carlo simulation, the 95th percentile hazard index in all groups was more than 1. Children and infants were more inclined towards risk than teens and adults based on the intake of nitrate and fluoride from drinking water. The Sobol sensitivity reflected that the nitrate concentration and ingestion rate are vital parameters that influence the outcome of the oral exposure model for all age groups. The interaction of ingestion rate with a concentration of nitrate and fluoride is an important parameter affecting the health risk assessment. In conclusion, these findings suggest that precise measures can reduce health risks and guarantee safe drinking water for residents of Shiraz County.

Rational design of electrocatalytic system to selective transform nitrate to nitrogen

Nitrate (NO3-) is one of the most common pollutants in natural bodies of water and as such threatens both human health and the safety of aquatic environment. There are efficient electrochemical techniques to directly remove NO3-, but inexpensive, selective and electrocatalytic strategies to eliminate NO3- by converting it into benign nitrogen (N2) remain challenging. This work studied Cu particles that were formed directly on a Ni foam (Cu-NF) and evaluated their electrocatalytic NO3- reduction performance. The use of carbon nanotubes (CNT) functionalized with titanium suboxides (TiSO) as the anode facilitated the generation of active chlorine species that had a key role in the removal of NH4+. An electrochemical system that integrated a Cu-NF cathode with a TiSO-CNT anode could remove 88.5% of NO3- with a >99% N2 selectivity when operated over 6 h (4.1 × 10-4 h-1) at a potential of -1.2 V vs Ag/AgCl. Because the chloride ions are very common in natural sources of water, this technique offers a sustainable and environmentally friendly approach for the removal of NO3- from contaminated water sources.

Si3C Monolayer as an Efficient Metal-Free Catalyst for Nitrate Electrochemical Reduction: A Computational Study

Nitrate electroreduction reaction to ammonia (NO3ER) holds great promise for both nitrogen pollution removal and valuable ammonia synthesis, which are still dependent on transition-metal-based catalysts at present. However, metal-free catalysts with multiple advantages for such processes have been rarely reported. Herein, by means of density functional theory (DFT) computations, in which the Perdew-Burke-Ernzerhof (PBE) functional is obtained by considering the possible van der Waals (vdW) interaction using the DFT+D3 method, we explored the potential of several two-dimensional (2D) silicon carbide monolayers as metal-free NO3ER catalysts. Our results revealed that the excellent synergistic effect between the three Si active sites within the Si3C monolayer enables the sufficient activation of NO3- and promotes its further hydrogenation into NO2*, NO*, and NH3, making the Si3C monolayer exhibit high NO3ER activity with a low limiting potential of -0.43 V. In particular, such an electrochemical process is highly dependent on the pH value of the electrolytes, in which acidic conditions are more favorable for NO3ER. Moreover, ab initio molecular dynamics (AIMD) simulations demonstrated the high stability of the Si3C monolayer. In addition, the Si3C monolayer shows a low formation energy, excellent electronic properties, a superior suppression effect on competing reactions, and high stability, offering significant advantages for its experimental synthesis and practical applications in electrocatalysis. Thus, a Si3C monolayer can perform as a promising NO3ER catalyst, which would open a new avenue to further develop novel metal-free catalysts for NO3ER.

Chlorine-mediated electrochemical advanced oxidation process for ammonia removal: Mechanisms, characteristics and expectation

Chlorine-Mediated Electrochemical Advanced Oxidation (Cl-EAO) technology is a promising approach for ammonia removal from wastewater due to its numerous advantages, including small infrastructure, short processing time, easy operation, high security, and high nitrogen selectivity. This paper provides a review of the ammonia oxidation mechanisms, characteristics, and anticipated applications of Cl-EAO technology. The mechanisms of ammonia oxidation encompass breakpoint chlorination and chlorine radical oxidation, although the contributions of active chlorine, Cl, and ClO remain uncertain. This study critically examines the limitations of existing research and suggests that a combination of determining free radical concentration and simulating a kinetic model would help elucidate the contributions of active chlorine, Cl, and ClO to ammonia oxidation. Furthermore, this review comprehensively summarizes the characteristics of ammonia oxidation, including kinetic properties, influencing factors, products, and electrodes. The amalgamation of Cl-EAO technology with photocatalytic and concentration technologies has the potential to enhance ammonia oxidation efficiency. Future research should concentrate on clarifying the contributions of active chlorine, Cl, and ClO to ammonia oxidation, the production of chloramines and other byproducts, and the development of more efficient anodes for the Cl-EAO process. The main objective of this review is to enhance the understanding of the Cl-EAO process. The findings presented herein contribute to the advancement of Cl-EAO technology and provide a foundation for future studies in this field.

Fertigation to recover nitrate-polluted aquifer and improve a long time eutrophicated lake, Spain

Use of nitrogen and phosphorus in agriculture increases agricultural production but also generates important environmental problems around the world, such as high nitrate levels in aquifers and an increase in eutrophication of waters. A set of tools and models are used, ENVIRO-GRO and PATRICAL models, to analyse the effect of large irrigation system modernization, 13,700 ha, from traditional flood irrigation to modernized drip irrigation, in the aquifer nitrate levels and in the phosphorus inputs to a 50-years eutrophicated RAMSAR lake, Albufera lake. Based on data collected from end users, modernized irrigation system reduces the amount of nitrogen applied from 25 % to 45 % and phosphorus applied around 90-95 %, so phosphorus content on soil, phosphorus legacy, is reducing by time. Obtained results indicate that nitrogen leaching as nitrate is reduced by 70 % to 83 % and surface runoff during irrigation events disappear, hence phosphorus contributions to surface waters are eliminated. Nitrate polluted aquifer will be recovered in 5-6 years after complete implement of measures and phosphorus inputs to the lake are reduced around 20 % contributing to improve the status of the eutrophicated Albufera lake. Results show great agreement with the European Strategy to reduce the use of fertilizers and how the fertilizers technical management in fertigation can contribute to greater efficiency in it use and improvement of the environment.

Healthy Drinking Water as a Necessity in Developing Countries Like India: A Narrative review

Water is an indispensable part of human life. This article is an extensive review that focuses on the importance of water to sustain human life, the necessity of healthy, safe drinking water, and the health hazards of drinking untreated and contaminated water. We drink treated water thinking it to be safe without the knowledge that it, too, has harmful effects. Detrimental health effects due to water chlorination are mentioned in this article. The usage of nanoparticles for the treatment of water is an alternative to chlorination, but they are little in use as they are expensive. Transmission of waterborne diseases through drinking water is widespread in a developing country like India. A list of the pathogens contaminating drinking water is present in the review. Pathogens pollute water, and heavy metals and chemicals from industries, pesticides, pharmaceutical compounds, and radioactive waste also taint it. The harmful effects of metal and chemical toxicities on human health are discussed in this review. The government of India has launched several programmes to ensure clean, safe drinking water for all its residents. The study reflects on the treatment given to individuals suffering from waterborne diseases in India. Significant changes in health status in India have been seen recently after the execution of various government programmes to provide safe, healthy drinking water to all its residents.

A novel hypothermic strain, Pseudomonas reactans WL20-3 with high nitrate removal from actual sewage, and its synergistic resistance mechanism for efficient nitrate removal at 4 °C

Nitrate can be well removed by bacteria at 25-30 °C. However, nitrate removal almost ceases at temperatures lower than 5 °C. In this study, a novel hypothermic strain, Pseudomonas reactans WL20-3 exhibited an excellent aerobic nitrate removal ability at 4 °C. It had high capability for the removal of nitrate, total dissolved nitrogen (TDN), and dissolved organic carbon (DOC) at 4 °C, achieving removal efficiencies of 100%, 87.91%, and 97.48%, respectively. The transcriptome analysis revealed all genes involved in the nitrate removal pathway were significantly up-regulated. Additionally, the up-regulation of ABC transporter genes and down-regulation of respiratory chain genes cooperated with the nitrate metabolism pathway to resist low-temperature stress. In actual sewage, inoculated with WL20-3, the nitrate removal efficiency was found to be 70.70%. Overall, these findings demonstrated the impressive capacity of the novel strain WL20-3 to remove nitrate and provided novel insights into the synergistic resistance mechanism of WL20-3 at low temperature.

Nitrates in Turkish waters: sources, mechanisms, impacts, and mitigation

Intensive technological developments, rapid population growth and urbanization, and excessive use of nitrogen fertilizers have caused water resources to be contaminated substantially by nitrates in Turkey. The accumulated information should be evaluated to draw a nationwide attention to the problem. The aim of this review article was to highlight the importance of nitrate (NO3) contamination and to discuss the measures to be taken to mitigate the contamination across the nation. Agriculture, especially chemical fertilizers used in irrigated agriculture, was the most important source of NO3 in groundwater. Also, the industrial and domestic discharges substantially contributed to NO3 in both groundwater and surface waters in many cases. The most severe and widespread groundwater (e.g., 344 mg NO3 L-1 in İzmir, 476 mg L-1 in Afyon, 477 mg L-1 in Antalya, and 948.0 mg L-1 in Konya) and surface water contaminations (e.g., 293.8 mg NO3 L-1 in İzmir, 63.3 mg L-1 in Eskişehir, 89.8 mg L-1 in Edirne, and 90.6 mg L-1 in Sakarya) occurred in the regions where intensive agriculture, industrial development, and rapid urbanization were clustered. Well-established irrigation and fertilizer management plans are critical for reducing fertilizer-related NO3 contaminations in the irrigated agriculture. Special attention should be given to the regions where industrially and domestically contaminated running water bodies are in contact with groundwater. Discharge of wastewaters to the streams, creeks, rivers, and lakes should be prevented. Well-designed studies are needed to evaluate potential health effects, including the risk of cancer, of NO3 in drinking water.

Spatio-temporal assessment of water quality of a tropical decaying river in India for drinking purposes and human health risk characterization

River water pollution and water-related health problems are common issues across the world. The present study aims to examine the Jalangi River's water quality to assess its suitability for drinking purposes and associated human health risks. The 34 water samples were collected from the source to the mouth of Jalangi River in 2022 to depict the spatial dynamics while another 119 water samples (2012-2022) were collected from a secondary source to portray the seasonal dynamics. Results indicate better water quality in the lower reach of the river in the monsoon and post-monsoon seasons. Principal component analysis reveals that K+, NO3-, and total alkalinity (TA) play a dominant role in controlling the water quality of the study region, while, CaCO3, Ca2+, and EC in the pre-monsoon, EC, TDS, Na+, and TA in the monsoon, and EC, TDS and TA in the post-monsoon controlled the water quality. The results of ANOVA reveal that BOD, Ca2+, and CaCO3 concentrations in water have significant spatial dynamics, whereas pH, BOD, DO, Cl-, SO42-, Na+, Mg2+, Ca2+, CaCO3, TDS, TA, and EC have seasonal dynamics (p < 0.05). The water quality index depicts that the Jalangi River's water quality ranged from 6.23 to 140.83, i.e., excellent to unsuitable for drinking purposes. Human health risk analysis shows that 32.35% of water samples have non-carcinogenic health risks for all three groups of people, i.e., adults, children, and infants while only 5.88% of water samples have carcinogenic health risks for adults and children. The gradual decay of the Jalangi River coupled with the disposal of urban and agricultural effluents induces river pollution that calls for substantial attention from the various stakeholders to restore the water quality.

Inactivation of Foodborne Pathogens by Lactiplantibacillus Strains during Meat Fermentation: Kinetics and Mathematical Modelling

This study examined the effect of beef fermentation with Lactiplantibacillus paraplantarum (L) PTCC 1965, Lactiplantibacillus (L) plantarum subsp. plantarum PTCC 1745, and Lactiplantibacillus (L) pentosus PTCC 1872 bacteria on the growth of pathogenic bacteria, including Salmonella (S) Typhi PTCC 1609 and Staphylococcus (S) aureus PTCC 1826. The growth of lactic acid bacteria (LAB) and the effect of fermentation on pathogenic bacteria were studied using Weibull: biphasic linear and competitive models. The results showed that the rate of pH reduction was lower in the early stages and increased as the microbial population grew. The α parameter was lower for L. plantarum subsp. plantarum compared to L. paraplantarum and L. pentosus. The comparison of the α parameter for bacterial growth and pH data showed that the time interval required to initiate the rapid growth phase of the bacteria was much shorter than that for the rapid pH reduction phase. The pH value had a 50% greater effect on the inactivation of S. Typhi when compared to the samples containing L. plantarum subsp. plantarum and L. pentosus. The same parameter was reported to be 72% for the inactivation of St. aureus. In general, during the fermentation process, LAB strains caused a decrease in pH, and as a result, reduced the growth of pathogens, which improves consumer health and increases the food safety of fermented meat.

A comprehensive review on monitoring and purification of water through tunable 2D nanomaterials

Instead of typical household trash, the heavy metal complexes, organic chemicals, and other poisons produced by huge enterprises threaten water systems across the world. In order to protect our drinking water from pollution, we must keep a close eye on the situation. Nanotechnology, specifically two-dimensional (2D) nanomaterials, is used in certain wastewater treatment systems. Graphene, g-C3N4, MoS2, and MXene are just a few examples of emerging 2D nanomaterials that exhibit an extraordinary ratio of surface (m3), providing material consumption, time consumption, and treatment technique for cleaning and observing water. In this post, we'll talk about the ways in which 2D nanomaterials may be tuned to perform certain functions, namely how they can be used for water management. The following is a quick overview of nanostructured materials and its possible use in water management: Also discussed in length are the applications of 2D nanomaterials in water purification, including pollutant adsorption, filtration, disinfection, and photocatalysis. Fluorescence sensors, colorimetric, electrochemical, and field-effect transistors are only some of the devices being studied for their potential use in monitoring water quality using 2D nanomaterials. Utilizing 2D content has its benefits and pitfalls when used to water management. New developments in this fast-expanding business will boost water treatment quality and accessibility in response to rising awareness of the need of clean, fresh water among future generations.

Spatial association of surface water quality and human cancer in China

Little is known about the association between surface water quality and cancer incidence, especially in China. Drinking water quality has been linked to the incidence of several cancers in individual-level studies. However, few studies have attempted to examine multiple pollutants and multiple cancers at population level. This study used water monitoring and population-level cancer data from across China to examine spatial associations between water pollutants and types of cancer. We found a “dose–response” relationship between the number of pollutants present at high levels and cancer incidence. These results provide evidence of a nationwide spatial association between water quality and cancer in China. The precise relationship varies with cancers and pollutants. However, the overall consistency of the “dose–response” relationship suggests that surface water quality is an important factor in cancer incidence. Our findings highlight new issues such as the changing effects when different pollutants co-exist and an increasing number of new cancer cases partially attributable to poor water quality. Our work also points to some ways to deal with these challenges.

Water Quality Index and Human Health Risk Assessment of Drinking Water in Selected Urban Areas of a Mega City

The present study was conducted to evaluate the quality of drinking water and assess the potential health hazards due to water contaminants in selected urban areas of Lahore, Pakistan. Water samples were collected from ten sites and analyzed for different physico-chemical parameters including turbidity, color, pH, total dissolved solids (TDS), nitrates, fluoride, residual chlorine, and total hardness. Additionally, heavy metal (arsenic) and microbial parameters (E. coli) were also determined in the water samples. Drinking water quality evaluation indices, including the water quality index (WQI) for physico-chemical and biological parameters and human health risk assessment (HHRA) for heavy metal were estimated using the analytical results of the target parameters. It was found in most of the areas that the levels of arsenic, fluoride, TDS, and residual chlorine were higher than those recommended by the National Environmental Quality Standard (NEQS) and World Health Organization (WHO) guidelines. In addition to the physico-chemical parameters, microbial content (E. coli) was also found in the drinking water samples of the selected areas. Statistical analysis of the results indicated that levels of target parameters in drinking water samples are significantly different between sampling sites. The WQI for all physico-chemical and microbial parameters indicated that drinking water in most of the areas was unfit and unsuitable (WQI > 100) for drinking purposes except for the water of Bhatti Gate and Chota Gaon Shahdara with a WQI of 87 and 91, respectively. Drinking water in these areas had a very poor WQI rating. According to HHRA, drinking water from the selected sites was found to be of high risk to children and adults. The carcinogenic risk of arsenic indicated that all samples were of high risk to both adults and children (4.60 and 4.37 × 10^-3, respectively). Regular monitoring of drinking water quality is essential, and proactive measures must be implemented to ensure the treatment and availability of safe drinking water in urban areas.

Electrochemical nitrate reduction to high-value ammonia on two-dimensional molybdenum carbide nanosheets for nitrate-containing wastewater upcycling

Electrochemical conversion of nitrate wastewater into high-value ammonia fertilizer has attracted extensive attention in wastewater treatment and resource recovery, but presents great challenges due to complicated reaction pathways and competing side reactions. Herein, we report a feasible method for the successful fabrication of Mo₂C nanosheets (Mo₂C NSs) as electrocatalyst for the electroreduction of nitrate to ammonia. Compared to Mo₂C nanoparticles, the Mo₂C NSs exhibited superior activity and selectivity in NH₃ electrosynthesis with an NH₃ yield rate of 25.2 mg·h^-1·mg^-1_cat. at -0.4 V and a Faradaic efficiency of 81.4 % at -0.3 V versus reversible hydrogen electrode. The X-ray diffraction and transmission electron microscopy characterization verifted the controllable conversion of 2D MoO₂ NSs into 2D Mo₂C NSs. In situ spectroscopic studies and on-line differential electrochemical mass spectrometry revealed the proposed reaction pathway of NO₃^- to NH₃ conversion, *NO₃^- → *NO₂^- → *NO→*NOH → *NH₂OH → *NH₃. Density functional theory calculations further verified the effective N-end NOH pathway with the conversion of *NH₂OH to *NH₂ as the rate-determining step requiring a low energy barrier of 0.58 eV. Importantly, the key hydrogenation of *NO to form *NOH species underwent a lower energy barrier of 0.39 eV compared with the formation of *ONH species (1.06 eV).

Curcumin: Overview of Extraction Methods, Health Benefits, and Encapsulation and Delivery Using Microemulsions and Nanoemulsions

Curcumin is the principal curcuminoid found in the rhizomes of turmeric. Due to its therapeutic action against cancer, depression, diabetes, some bacteria, and oxidative stress, it has been used widely in medicine since ancient times. Due to its low solubility, the human organism cannot completely absorb it. Advanced extraction technologies, followed by encapsulation in microemulsion and nanoemulsion systems, are currently being used to improve bioavailability. This review discusses the different methods available for curcumin extraction from plant material, methods for the identification of curcumin in the resulting extracts, its beneficial effects on human health, and the encapsulation techniques into small colloidal systems that have been used over the past decade to deliver this compound.

Comparing methods to deposit Pd-In catalysts on hydrogen-permeable hollow-fiber membranes for nitrate reduction

Catalytic hydrogenation of nitrate in water has been studied primarily using nanoparticle slurries with constant hydrogen-gas (H₂) bubbling. Such slurry reactors are impractical in full-scale water treatment applications because 1) unattached catalysts are difficult to be recycled/reused and 2) gas bubbling is inefficient for delivering H₂. Membrane Catalyst-film Reactors (MCfR) resolve these limitations by depositing nanocatalysts on the exterior of gas-permeable hollow-fiber membranes that deliver H₂ directly to the catalyst-film. The goal of this study was to compare the technical feasibility and benefits of various methods for attaching bimetallic palladium/indium (Pd/In) nanocatalysts for nitrate reduction in water, and subsequently select the most effective method. Four Pd/In deposition methods were evaluated for effectiveness in achieving durable nanocatalyst immobilization on the membranes and repeatable nitrate-reduction activity: (1) In-Situ MCfR-H₂, (2) In-Situ Flask-Synthesis, (3) Ex-Situ Aerosol Impaction-Driven Assembly, and (4) Ex-Situ Electrostatic. Although all four deposition methods achieved catalyst-films that reduced nitrate in solution (≥ 1.1 min^-1gPd^-1), three deposition methods resulted in significant palladium loss (>29%) and an accompanying decline in nitrate reactivity over time. In contrast, the In-Situ MCfR-H₂ deposition method had negligible Pd loss and remained active for nitrate reduction over multiple operational cycles. Therefore, In-Situ MCfR-H₂ emerged as the superior deposition method and can be utilized to optimize catalyst attachment, nitrate-reduction, and N₂ selectivity in future studies with more complex water matrices, longer treatment cycles, and larger reactors.

Dietary Factors and Pancreatic Cancer Risk: An Umbrella Review of Meta-Analyses of Prospective Observational Studies

Dietary factors may be associated with the occurrence of pancreatic cancer. This umbrella review aimed to review and grade the evidence for the associations between dietary factors and pancreatic cancer risk. We searched PubMed, EMBASE, Web of Science, Scopus, Cochrane Database of Systematic Reviews, and CINAHL for eligible literature. We included meta-analyses of randomized controlled trials (RCTs) or prospective observational studies. We used AMSTAR-2, a measurement tool to assess systematic reviews, to evaluate the methodological quality of the included meta-analyses. For each association, we calculated the summary effect size, 95% CI, heterogeneity, number of cases, 95% prediction interval, small-study effect, and excess significance bias. The protocol for this review was registered in the PROSPERO database (CRD42022333669). We included 41 meta-analyses of prospective observational studies describing 59 associations between dietary factors and pancreatic cancer risk. None of the retrieved meta-analyses included RCTs. No association was supported by convincing or highly suggestive evidence; however, there was suggestive evidence of a positive association between fructose intake and pancreatic cancer risk. There was weak evidence for an inverse association of nuts intake or adherence to the Mediterranean diet with pancreatic cancer incidence, and for positive associations between a higher intake of red meat or heavy alcohol intake and pancreatic cancer incidence. The remaining 54 associations were nonsignificant. Consistent with the American Institute for Cancer Research review, this umbrella review found that regular consumption of nuts and reduced intake of fructose, red meat, and alcohol were associated with a lower risk of pancreatic cancer. Emerging weak evidence supported an inverse association between adherence to the Mediterranean diet and pancreatic cancer risk. As some associations were rated as weak and most were considered nonsignificant, further prospective studies are needed to investigate the role of dietary factors and risk of pancreatic cancer.

Environmental exposure to perchlorate, nitrate, and thiocyanate in relation to chronic kidney disease in the general US population, NHANES 2005-2016

BACKGROUND

Few studies have explored the impact of perchlorate, nitrate, and thiocyanate (PNT) on kidney function. This study aimed to evaluate the association of urinary levels of PNT with renal function as well as the prevalence of chronic kidney disease (CKD) among the general population in the United States.

METHODS

This analysis included data from 13,373 adults (≥20 years) from the National Health and Nutrition Examination Survey 2005 to 2016. We used multivariable linear and logistic regression, to explore the associations of urinary PNT with kidney function. Restricted cubic splines were used to assess the potentially non-linear relationships between PNT exposure and outcomes.

RESULTS

After traditional creatinine adjustment, perchlorate (P-traditional) was positively associated with estimated glomerular filtration rate (eGFR) (adjusted β: 2.75; 95% confidence interval [CI]: 2.25 to 3.26; P < 0.001), and negatively associated with urinary albumin-to-creatinine ratio (ACR) (adjusted β: -0.05; 95% CI: -0.07 to -0.02; P = 0.001) in adjusted models. After both traditional and covariate-adjusted creatinine adjustment, urinary nitrate and thiocyanate were positively associated with eGFR (all P values <0.05), and negatively associated with ACR (all P values <0.05); higher nitrate or thiocyanate was associated with a lower risk of CKD (all P values <0.001). Moreover, there were L-shaped non-linear associations between nitrate, thiocyanate, and outcomes. In the adjusted models, for quartiles of PNT, statistically significant dose-response associations were observed in most relationships. Most results were consistent in the stratified and sensitivity analyses.

CONCLUSIONS

Exposures to PNT might be associated with kidney function, indicating a potential beneficial effect of environmental PNT exposure (especially nitrate and thiocyanate) on the human kidney.

Polyaniline-Supported Nickel Oxide Flower for Efficient Nitrite Electrochemical Detection in Water

A modified electrode with conducting polymer (Polyaniline) and NiO nanoflowers was prepared to detect nitrite ions in drinking water. A simple method was used to prepare the NiO nanoflower (NiOnF). Several techniques characterized the as-prepared NiOnF to determine the chemical structure and surface morphology of the NiO, such as XRD, XPS, FT-IR, and TGA. The activity of the electrode toward nitrite sensing was investigated over a wide range of pH (i.e., 2 to 10). The amperometry method was used to determine the linear detection range and limit. Accordingly, the modified electrode GC/PANI/NiOnf showed a linear range of detection at 0.1-1 µM and 1-500 µM. At the same time, the limit of detection (LOD) was 9.7 and 64 nM for low and high concentrations, respectively. Furthermore, the kinetic characteristics of nitrite, such as diffusion and transport coefficients, were investigated in various media. Moreover, the charge transfer resistance was utilized for nitrite electrooxidation in different pH values by the electrochemical impedance technique (EIS). The anti-interfering criteria of the modified surfaces were utilized in the existence of many interfering cations in water (e.g., K+, Na+, Cu2+, Zn2+, Ba2+, Ca2+, Cr2+, Cd2+, Pd2+). A real sample of the Nile River was spiked with nitrite to study the activity of the electrode in a real case sample (response time ~4 s). The interaction between nitrite ions and NiO{100} surface was studied using DFT calculations as a function of adsorption energy.

Geochemistry, stable isotopes and statistic tools to estimate threshold and source of nitrate in groundwater (Sardinia, Italy)

In the European Union, nitrate vulnerable zone (NVZ) should be designed for the mitigation of nitrate (NO₃^-) contamination caused by agricultural practices. Before establishing new NVZ, the sources of NO₃^- must be recognized. A geochemical and multiple stable isotopes approach (hydrogen, oxygen, nitrogen, sulfur and boron) and statistical tools were applied to define the geochemical characteristics of groundwater (60 samples), calculate the local NO₃^- threshold and assess potential sources of NO₃^- contamination in two study areas (hereafter Northern and Southern), located in a Mediterranean environment (Sardinia, Italy). Results of the integrated approach applied to two case study, permits to highlight the strengths of integrating geochemical and statistical methods to provide nitrate source identification as a reference by decision makers to remediate and mitigate nitrate contamination in groundwater. Hydrogeochemical features in the two study areas were similar: near neutral to slightly alkaline pH, electrical conductivity in the range of 0.3 to 3.9 mS/cm, and chemical composition ranging from Ca-HCO₃^- at low salinity to Na-Cl^- at high salinity. Concentrations of NO₃^- in groundwater were in the range of 1 to 165 mg/L, whereas the nitrogen reduced species were negligible, except few samples having NH₄⁺ up to 2 mg/L. Threshold values in the studied groundwater samples were between 4.3 and 6.6 mg/L NO₃^-, which was in agreement with previous estimates in Sardinian groundwater. Values of δ³⁴S and δ¹⁸O_SO4 of SO₄^2- in groundwater samples indicated different sources of SO₄^2-. Sulfur isotopic features attributed to marine SO₄^2- were consistent with groundwater circulation in marine-derived sediments. Other source of SO₄^2- were recognize due to the oxidation of sulfide minerals, to fertilizers, manure, sewage fields, and SO₄^2- derived from a mix of different sources. Values of δ¹⁵N and δ¹⁸O_NO3 of NO₃^- in groundwater samples indicated different biogeochemical processes and NO₃^- sources. Nitrification and volatilization processes might have occurred at very few sites, and denitrification was likely to occur at specific sites. Mixing among various NO₃^- sources in different proportions might account for the observed NO₃^- concentrations and the nitrogen isotopic compositions. The SIAR modeling results showed a prevalent NO₃^- source from sewage/manure. The δ¹¹B signatures in groundwater indicated the manure to be the predominant NO₃^- source, whereas NO₃^- from sewage was recognized at few sites. Geographic areas showing either a predominant process or a defined NO₃^- source where not recognize in the studied groundwater. Results indicate widespread contamination of NO₃^- in the cultivated plain of both areas. Point sources of contamination, due to agricultural practices and/or inadequate management of livestock and urban wastes, were likely to occur at specific sites.

Research Progress of Nitrite Metabolism in Fermented Meat Products

Nitrite is a common color and flavor enhancer in fermented meat products, but its secondary amines may transfer to the carcinogen N-nitrosamines. This review focuses on the sources, degradation, limitations, and alteration techniques of nitrite. The transition among NO3− and NO2−, NH4+, and N2 constitutes the balance of nitrogen. Exogenous addition is the most common source of nitrite in fermented meat products, but it can also be produced by contamination and endogenous microbial synthesis. While nitrite is degraded by acids, enzymes, and other metabolites produced by lactic acid bacteria (LAB), four nitrite reductase enzymes play a leading role. At a deeper level, nitrite metabolism is primarily regulated by the genes found in these bacteria. By incorporating antioxidants, chromogenic agents, bacteriostats, LAB, or non-thermal plasma sterilization, the amount of nitrite supplied can be decreased, or even eliminated. Finally, the aim of producing low-nitrite fermented meat products is expected to be achieved.

Associations of thiocyanate, nitrate, and perchlorate exposure with dyslipidemia: a cross-sectional, population-based analysis

The aim of this study was to assess the associations of urinary thiocyanate, nitrate, and perchlorate concentrations with dyslipidemia, individually and in combination, which has not previously been studied. Data from the 2001-2002 and 2005-2016 National Health and Nutrition Examination Surveys (NHANES) were analyzed in this cross-sectional study. The dependent variables were continuous serum lipid variables (triglycerides [TG], total cholesterol [TC], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], non-HDL-C, and apolipoprotein B [Apo B]) and binary serum lipid variables, with the latter reflecting dyslipidemia (elevated TG, ≥ 150 mg/dL; elevated TC, ≥ 200 mg/dL; elevated LDL-C, ≥ 130 mg/dL; lowered HDL-C, < 40 mg/dL in men and < 5 0 mg/dL in women; elevated non-HDL-C, ≥ 160 mg/dL; and elevated Apo B, ≥ 130 mg/dL). Multivariate logistic, linear, and weighted quantile sum (WQS) regression analyses were used to explore the associations of thiocyanate, nitrate, and perchlorate with the continuous and binary serum lipid variables. The linearity of the associations with the binary serum lipid variables was assessed using restricted cubic spline (RCS) regression. A total of 15,563 adults were included in the analysis. The multivariate linear and logistic regression analyses showed that thiocyanate was positively associated with multiple continuous (TG, TC, LDL-C, non-HDL-C, and Apo B, but not HDL-C) and binary (elevated TG, TC, LDL-C, and non-HDL-C) serum lipid variables, whereas perchlorate was negatively associated with elevated LDL-C. Multivariate RCS logistic regression revealed a linear dose-response relationship between thiocyanate and elevated TG, TC, LDL-C, non-HDL-C, and Apo B, but a nonlinear relationship with lowered HDL-C (inflection point = 1.622 mg/L). WQS regression showed that a mixture of thiocyanate, nitrate, and perchlorate was positively associated with all binary serum lipid variables except for Apo B. Our findings indicate that urinary thiocyanate, nitrate, and perchlorate concentrations, individually and in combination, were associated with dyslipidemia.

A comprehensive review on mixotrophic denitrification processes for biological nitrogen removal

Biological denitrification is the most widely used method for nitrogen removal in water treatment. Compared with heterotrophic and autotrophic denitrification, mixotrophic denitrification is later studied and used. Because mixotrophic denitrification can overcome some shortcomings of heterotrophic and autotrophic denitrification, such as a high carbon source demand for heterotrophic denitrification and a long start-up time for autotrophic denitrification. It has attracted extensive attention of researchers and is increasingly used in biological nitrogen removal processes. However, so far, a comprehensive review is lacking. This paper aims to review the current research status of mixotrophic denitrification and provide guidance for future research in this field. It is shown that mixotrophic denitrification processes can be divided into three main kinds based on different kinds of electron donors, mainly including sulfur-, hydrogen-, and iron-based reducing substances. Among them, sulfur-based mixotrophic denitrification is the most widely studied. The most concerned influencing factors of mixotrophic denitrification processes are hydraulic retention times (HRT) and ratio of chemical oxygen demand (COD) to total inorganic nitrogen (C/N). The dominant functional bacteria of sulfur-based mixotrophic denitrification system are Thiobacillus, Azoarcus, Pseudomonas, and Thauera. At present, mixotrophic denitrification processes are mainly applied for nitrogen removal in drinking water, groundwater, and wastewater treatment. Finally, challenges and future research directions are discussed.

Nitrate contamination in drinking water and adverse reproductive and birth outcomes: a systematic review and meta-analysis

Exposure to low levels of nitrate in drinking water may have adverse reproductive effects. We reviewed evidence about the association between nitrate in drinking water and adverse reproductive outcomes published to November 2022. Randomized trials, cohort or case-control studies published in English that reported the relationship between nitrate intake from drinking water and the risk of perinatal outcomes were included. Random-effect models were used to pool data. Three cohort studies showed nitrate in drinking water is associated with an increased risk of preterm birth (odds ratio for 1 mg/L NO3-N increased (OR1) = 1.01, 95% CI 1.00, 1.01, I2 = 23.9%, 5,014,487 participants; comparing the highest versus the lowest nitrate exposure groups pooled OR (ORp) = 1.05, 95% CI 1.01, 1.10, I2 = 0%, 4,152,348 participants). Case-control studies showed nitrate in drinking water may be associated with the increased risk of neural tube defects OR1 = 1.06, 95% CI 1.02, 1.10; 2 studies, 2196 participants; I2 = 0%; and ORp = 1.51, 95% CI 1.12, 2.05; 3 studies, 1501 participants; I2 = 0%). The evidence for an association between nitrate in drinking water and risk of small for gestational age infants, any birth defects, or any congenital heart defects was inconsistent. Increased nitrate in drinking water may be associated with an increased risk of preterm birth and some specific congenital anomalies. These findings warrant regular review as new evidence becomes available.

Environmental exposure to perchlorate, nitrate and thiocyanate, and thyroid function in Chinese adults: A community-based cross-sectional study

BACKGROUND

Evidence on environmental exposure to perchlorate, nitrate, and thiocyanate, three thyroidal sodium iodine symporter (NIS) inhibitors, and thyroid function in the Chinese population remains limited.

OBJECTIVE

To investigate the associations of environmental exposure to perchlorate, nitrate, and thiocyanate with markers of thyroid function in Chinese adults.

METHODS

A total of 2441 non-pregnant adults (mean age 50.4 years and 39.1% male) with a median urinary iodine of 180.1 μg/L from four communities in Shenzhen were included in this cross-sectional study. Urinary perchlorate, nitrate, thiocyanate, and thyroid profiles, including serum free thyroxine (FT4), total thyroxine (TT4), free triiodothyronine (FT3), total triiodothyronine (TT3), and thyroid stimulating hormone (TSH), were measured. Generalized linear model was applied to investigate the single-analyte associations. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) models were used to examine the association between the co-occurrence of three anions and thyroid profile.

RESULTS

The median levels of urinary perchlorate, nitrate, and thiocyanate were 5.8 μg/g, 76.4 mg/g, and 274.1 μg/g, respectively. After adjusting for confounders, higher urinary perchlorate was associated with lower serum FT4, TT4, and TT3, and higher serum FT3 and TSH (all P < 0.05). Comparing extreme tertiles, subjects in the highest nitrate tertile had marginally elevated TT3 (β: 0.02, 95% CI: 0.00-0.04). Each 1-unit increase in log-transformed urinary thiocyanate was associated with a 0.04 (95% CI: 0.02-0.06) pmol/L decrease in serum FT3. The WQS indices were inversely associated with serum FT4, TT4, and FT3 (all P < 0.05). In the BKMR model, the mixture of three anions was inversely associated with serum FT4, TT4, and FT3.

CONCLUSIONS

Our study provides evidence that individual and combined environmental exposure to perchlorate, nitrate, and thiocyanate are associated with significant changes in thyroid function markers in the Chinese population with adequate iodine intake.

Inexact fuzzy-flexible left-hand-side chance-constrained programming for agricultural nonpoint-source water quality management

In this study, an inexact fuzzy-flexible left-hand-side chance-constrained programming (IFLCCP) method is proposed for optimizing an agricultural nonpoint-source water quality management problem under uncertainty. The developed method can address complex uncertainties resulted from system fuzzy flexible under various level of decision-making requirements and randomness parameters appeared on the left-hand side of the constraints, and deal with the conflict between water quality protection and agricultural system economic development. The IFLCCP model is formulated through incorporating inexact left-hand-sided chance-constrained programming into interval fuzzy flexible programming framework. The decision schemes obtained by the IFLCCP are analyzed under scenarios at different confidence level of environmental constraint. The results demonstrate that the scale of crop planting and breeding industries reduces as the confidence coefficient of environmental constraint (1-pi) increases, in order to satisfy pollutant discharge constraints, which results in the reduction of the system net benefit from scenarios 1 to 3. Meanwhile, the interval control variables λ± are introduced for quantifying the degrees of overall satisfaction for the objective function and the constraints, which get optimal adjustment to guarantee the net benefit to be as close as possible to the upper bound. The IFLCCP is able to provide management schemes with high system benefits under different levels of acceptable environmental risk, taking full consideration of decision makers' environmental management requirements. This study is a new application of the IFLCCP model to agricultural water quality management problem, demonstrating its applicability to practical environmental problems with high complexity and uncertainty.

Source identification and health risks of nitrate contamination in shallow groundwater: a case study in Subei Lake basin

Nitrate pollution of groundwater has become a global concern as it can affect drinking water quality and human health. In this paper, an extensive hydrochemical investigation was performed to assess the spatial distribution, source identification, and health risk of groundwater nitrate pollution in the Subei Lake basin. The prevalent pollutant, nitrate (NO₃^-), was identified based on descriptive statistical method and box plots, and most of the other parameters of groundwater samples met water standards and can be used for drinking purpose. The results showed that nearly 23.53% of groundwater samples displays the NO₃^- concentrations higher than the limit of 50 mg/L recommended by the World Health Organization, and the highest nitrate content (199 mg/L) is mainly distributed around the Mukai Lake. Piper triangle diagram demonstrated that the dominated anions of hydrochemical types exhibit a gradual evolving trend from HCO₃^- to SO₄^2- and Cl^- with increasing nitrate concentration. The correspondence analysis suggested that agricultural activities are identified as the most possible source of nitrate contamination, while the higher content of other parameters in individual groundwater samples may be controlled by natural factors. The impacts of pollutant NO₃^- on human health were quantified using human health risk assessment method, and results showed that the order of non-carcinogenic health risk values through drinking water intake is Infants>Children>Adult males>Adult females, and 65%, 53%, 41%, and 35% of samples exceed the acceptable risk level (hazard quotient=1), respectively. The main findings obtained from this study can provide valuable insight on drinking water safety and groundwater pollution prevention.

Epidemiology, Screening, and Prevention of Bladder Cancer

CONTEXT

Bladder cancer (BC) represents a significant health problem due to the potential morbidity and mortality associated with disease burden, which has remained largely unaltered over time.

OBJECTIVE

To provide an expert collaborative review and describe the incidence, prevalence, and mortality of BC and to evaluate current evidence for BC screening and prevention.

EVIDENCE ACQUISITION

Data on the estimated incidence and mortality of BC for 2020 in 185 countries were derived from the International Agency for Research on Cancer GLOBOCAN database. A review of English-language articles published over the past 5 yr was conducted using PubMed/MEDLINE to identify risk factors in addition to contemporary evidence on BC screening and prevention.

EVIDENCE SYNTHESIS

BC is the tenth most common cancer worldwide, with 573 278 cases in 2020. BC incidence is approximately fourfold higher in men than women. Tobacco smoking remains the principal risk factor, accounting for approximately 50% of cases. There is insufficient evidence to recommend routine BC screening. However, targeted screening of high-risk individuals (defined according to smoking history or occupational exposure) may reduce BC mortality and should be the focus of prospective randomized trials. In terms of disease prevention, smoking cessation represents the most important intervention, followed by a reduction in exposure to occupational and environmental carcinogens.

CONCLUSIONS

BC confers a significant disease burden. An understanding of BC epidemiology and risk factors provides an optimal foundation for disease prevention and the care of affected patients.

PATIENT SUMMARY

Bladder cancer is the tenth most common cancer worldwide and is approximately four times more common among men than among women. The main risk factors are tobacco smoking, followed by exposure to carcinogens in the workplace or the environment. Routine screening is not currently recommended, but may be beneficial in individuals at high risk, such as heavy smokers. Primary prevention is extremely important, and smoking cessation represents the most important action for reducing bladder cancer cases and deaths.

Oil tea shell synthesized biochar adsorptive utilization for the nitrate removal from aqueous media

Various reported methods are devoted to nitrate removal from water over the years. However, recently researchers are focusing on developing the materials that offer bio-based, non-toxic, inexpensive and yet an efficient solution for water treatment. In this study, removal of nitrates from water was carried out using oil tea shells (OTS) as a biosorbent. OTS powder was impregnated with ZnCl₂ and biochar was prepared which was further treated with Cetyltrimethylammonium bromide (CTAB), a cationic surfactant. Both the Langmuir and the Freundlich models were satisfied by the nitrate adsorption of OTS biochar. The adsorption capacity was measured at 15.6 mg/g when the circumstances were at their best. The pseudo-second-order model provided an accurate description of the kinetic data that were collected from batch trials. The adsorption yield goes up when by usage of more adsorbent, but it goes down when adsorption start with a higher concentration of nitrate. The strong basis of analytical equipments were used to characterize the OTS biosorbent. According to the findings of the research, surface-modified OTS biochar is an effective material for the removal of nitrate from aqueous solutions. This means that it has the potential to be utilized in water treatment as an adsorbent that is both inexpensive and kind to the natural environment. Removal of heavy metals and other organic pollutants, both from groundwater and wastewater using OTS biochar seems like a promising and interesting area of study.

Perchlorate, nitrate, and thiocyanate: Environmental relevant NIS-inhibitors pollutants and their impact on thyroid function and human health

Thyroid disruptors are found in food, atmosphere, soil, and water. These contaminants interfere with the thyroid function through the impairment of thyroid hormone synthesis, plasma transport, peripheral metabolism, transport into the target cells, and thyroid hormone action. It is well known that iodide uptake mediated by the sodium-iodide symporter (NIS) is the first limiting step involved in thyroid hormones production. Therefore, it has been described that several thyroid disruptors interfere with the thyroid function through the regulation of NIS expression and/or activity. Perchlorate, nitrate, and thiocyanate competitively inhibit the NIS-mediated iodide uptake. These contaminants are mainly found in food, water and in the smoke of cigarettes. Although the impact of the human exposure to these anions is highly controversial, some studies indicated their deleterious effects in the thyroid function, especially in individuals living in iodine deficient areas. Considering the critical role of thyroid function and the production of thyroid hormones for growth, metabolism, and development, this review summarizes the impact of the exposure to these NIS-inhibitors on thyroid function and their consequences for human health.

Groundwater characterization and non-carcinogenic and carcinogenic health risk assessment of nitrate exposure in the Mahanadi River Basin of India

Agriculture is the mainstay of India's economy and chemical fertilizers have been extensively used to meet increasing demands. Anthropogenic interventions at the soil surface, especially the application of nitrogenous fertilizers in agricultural fields, provide essential nutrients but become major pollutant sources in terrestrial ecosystems and aquatic environments. Groundwater samples from phreatic aquifers of the Mahanadi River Basin, Chhattisgarh, India, showed that the Ca²⁺-Mg²⁺-HCO₃^- freshwater type dominates, followed by the Ca²⁺-Mg²⁺-Cl- and Na⁺-HCO₃^- types. Increasing trends in the ionic ratios of (NO₃-+Cl-)/HCO₃- over TDS and of NO₃-/Cl- over Cl- indicated the significant impact of anthropogenic pollution on groundwater contamination. Deterministic and probabilistic approaches were used to assess the non-carcinogenic and carcinogenic health risks of nitrate to children and adults. Both approaches produced the same results and indicated children were more prone to non-carcinogenic health risk than adults. An excess gastric cancer risk (ER) exposure model showed that approximately 42% of the groundwater samples had a non-negligible ER (1.00 × 10^-4 to 1.00 × 10^-5). Sensitivity analysis indicated groundwater nitrate concentration, ingestion rate, and the percentage of nitrite from nitrate were the most significant variables in determining HI and ER. It is suggested to adopt proper management of control policies for reducing the elevated groundwater nitrate concentration in the present study area.

The Pyla-1 Natural Accession of Arabidopsis thaliana Shows Little Nitrate-Induced Plasticity of Root Development

Optimizing root system architecture is a strategy for coping with soil fertility, such as low nitrogen input. An ample number of Arabidopsis thaliana natural accessions have set the foundation for studies on mechanisms that regulate root morphology. This report compares the Columbia-0 (Col-0) reference and Pyla-1 (Pyl-1) from a coastal zone in France, known for having the tallest sand dune in Europe. Seedlings were grown on vertical agar plates with different nitrate concentrations. The lateral root outgrowth of Col-0 was stimulated under mild depletion and repressed under nitrate enrichment. The Pyl-1 produced a long primary root and any or very few visible lateral roots across the nitrate supplies. This could reflect an adaptation to sandy soil conditions, where the primary root grows downwards to the lower strata to take up water and mobile soil resources without elongating the lateral roots. Microscopic observations revealed similar densities of lateral root primordia in both accessions. The Pyl-1 maintained the ability to initiate lateral root primordia. However, the post-initiation events seemed to be critical in modulating the lateral-root-less phenotype. In Pyl-1, the emergence of primordia through the primary root tissues was slowed, and newly formed lateral roots stayed stunted. In brief, Pyl-1 is a fascinating genotype for studying the nutritional influences on lateral root development.

Efficient Nitrate Adsorption from Groundwater by Biochar-Supported Al-Substituted Goethite

Groundwater nitrate contamination is challenging and requires efficient solutions for nitrate removal. This study aims to investigate nitrate removal using a novel adsorbent, biochar-supported aluminum-substituted goethite (BAG). The results showed that an increase in the initial Al/(Al + Fe) atomic ratio for BAGs from 0 to 20% decreased the specific surface area from 115.2 to 75.7 m2/g, but enhanced the surface charge density from 0.0180 to 0.0843 C/m2. By comparison, 10% of Al/(Al + Fe) led to the optimal adsorbent for nitrate removal. The adsorbent’s adsorption capacity was effective with a wide pH range (4–8), and decreased with increasing ionic strength. The descending order of nitrate adsorption inhibition by co-existing anions was SO42−, HCO3−, PO43−, and Cl−. The adsorption kinetics and isotherms agreed well with the pseudo-first-order equation and Langmuir model, respectively. The theoretical maximum adsorption capacity was 96.1469 mg/g. Thermodynamic analysis showed that the nitrate adsorption was spontaneous and endothermic. After 10-cycle regeneration, the BAG still kept 92.6% of its original adsorption capacity for synthetic nitrate-contaminated groundwater. Moreover, the main adsorption mechanism was attributed to electrostatic attraction due to the enhancement of surface charge density by Al substitution. Accordingly, the BAG adsorbent is a potential solution to remove nitrate from groundwater.

Coffee Husk and Lignin Revalorization: Modification with Ag Nanoparticles for Heavy Metals Removal and Antifungal Assays

This study presents the use of the modified coffee husk and coffee lignin as sorbents in the heavy metal ions sorption of Pb(II), Cd(II), Cr(III), and Cu(II) in an aqueous solution. The modification of sorbents was carried out by the impregnation method, using silver nitrate (AgNO3) and sodium borohydride (NaBH4) as a nanoparticles’ (NPs) precursor, and reducing agent, respectively. The obtained nanocomposite material was morphologically characterized by electron microscopy. In addition, an evaluation of metal ions’ sorption, pseudo-first-order, and pseudo-second-order kinetics modeling was performed. Finally, antifungal activity was evaluated on different Candida species. Coffee and lignin modified with AgNPs increased the extraction capacity with the highest sorption for Pb ions with 2.56 mg/g and 1.44 mg/g, respectively.

Quantification and health risk assessment of nitrate in southern districts of Tehran, Iran

Nitrate is a common contaminant of drinking water. Due to its adverse health effects, this study aimed to determine nitrate levels in six southern districts of Tehran. A total of 148 samples were taken from tap waters. In 84.46% (n = 125) of the samples, the nitrate concentration was below national and WHO limits (50 mg/L); however, 15.54% (n = 23) were in violation of the criteria. The total mean concentration of nitrate was 36.15 mg/L (±14.74) ranging from 4.52 to 80.83 mg/L. The overall hazard quotient (HQ) for age groups were ordered as Children (1.71) &gt; Infants (1.24) &gt; Teenagers (1.2) &gt; Adults (0.96). In all districts, the HQ values for infants and children groups were greater than 1, indicating potential adverse health risks. In teenagers age group, only the HQ estimations of districts 10 (HQ = 0.93) and 11 (HQ = 0.74) were lower than 1 and in adults age group, the estimated HQ values for districts were lower than 1 with the exception for district 19 (HQ = 1.19). The sensitivity analysis (SA) showed that nitrate content plays a major role in the value of the assessed risk.