Tag: nutrition

Integrating water quality and water quantity to diagnose the health of water metabolism systems in multi-core multi-level urban agglomerations

Author links open overlay panelYing Yang a1

, Jing Wen a1

, Meirong Su b

, Qionghong Chen cShow moreAdd to MendeleyShareCite

https://doi.org/10.1016/j.watres.2025.123899Get rights and content

Highlights

  • •The MRIO table was compiled for a multi-core multi-level urban agglomeration.
  • •A diagnostic framework was established by coupling ENA and MRIO approaches.
  • •Water quantity-water quality linkage was considered in the diagnostic framework.
  • •The IWMN was less vigorous and less organized than the QWMN.
  • •The IWMN tended slightly towards mutualism but had more negative collaborations.

Abstract

Urban agglomerations (UAs) are compelled to scrutinize the health of their water systems as the frequency of water crises increases. An urban water system’s health is closely related to metabolism processes. To date, water systems in multi-core multi-level UAs have not been analyzed using water quantity and water quality because of methodological constraints. To address this research gap, we developed an integrated water quality–water quantity model for diagnosing water metabolism systems that could process nested multi-region input-output (MRIO) tables. We coupled the MRIO tables and established two networks, an integrated water quantity–quality metabolism network (IWMN) and a water quantity metabolism network (QWMN). We tested the two networks with data from the Guangdong-Hong Kong-Macao UA and assessed four aspects of the networks’ health, namely vigor, organization, resilience, and collaboration, using ecological network analysis. We discovered that IWMN exhibited lower vigor (internal circulation 10.4 %) and organization dominated by dependency (total contribution intensity σ = -23) compared to the QWMN. Polity-driven disparities shaped the robustness distribution, while a mutualism tendency coexisted with a complex exploitation relationship (52.4 %), particularly in the core large-sized city of Hong Kong, where 58 new competitive pairs emerged. Thus, we recommend prioritizing Guangdong-Hong Kong-Macao trade optimization for high-water-content products to enhance system health.

Graphical abstract

Image, graphical abstract

Introduction

The surface water deficit experienced in 482 of the world’s largest cities is projected to reach 6.75 million tons by 2050 because of an imbalance between the water supply and the demand (Flörke et al., 2018). This trend has prompted growing interest in resource allocation and environmental protection within urban agglomerations (UAs). UAs are composed of multiple geographically adjacent cities with diverse sizes and characteristics (Fang et al., 2015). Diverse UAs with multi-core structures (classified by comprehensive urban engine functions) and multi-level systems (quantified by social indicators) face challenges due to high heterogeneity in population size and spatial resource allocation (Han et al., 2019; Chirigati, 2022; Zhao et al., 2021). Water quantity and water quality are important attributes of water resources. Changes in the water quantity caused by a lack of rainfall or heavy rainfall events affect the water quality by concentrating pollutants or diluting. Conversely, degraded water quality diminishes the availability of water resources (Li et al., 2023) and has direct effects on urban aquatic ecosystems (Liu and Yang, 2012). Therefore, to optimize water management in multi-core multi-level UAs, we need to know more about the combined effects of water quality and water quantity on the water resources.

When optimizing water management in urban areas, the water metabolism mechanism of the system should be analyzed, and key issues should be identified (Cao et al., 2021; He et al., 2020b; Liu et al., 2022). The concept of water metabolism originates from urban metabolism (Wolman, 1965), which describes water cycle processes (e.g., water input, output, and storage) driven by social activities in different cities (Wang and Chen, 2010). This concept can effectively identify hidden risks resulting from the allocation of social resources—such as population, industry and environment within UAs, thus challenging the traditional multilevel paradigm of urban water management. In assessing the health of water systems based on water metabolism mechanisms, processes analogous to those in natural ecosystems, such as vigor and collaboration (Y.J. Yang et al., 2020; Zhu et al., 2020), sustained and stable organization, and adaptability to external pressures (Yan et al., 2014), are employed. However, to date, most research has primarily focused on the efficiency of consumptive activities (Nishimura et al., 2021; Qi et al., 2021; Xu et al., 2020), while ignoring the underlying water metabolism processes.

Network methods are effective for characterizing critical resource metabolism processes (Liang et al., 2020). Ecological Network Analysis (ENA) (Hannon B, 1973) quantifies metabolic features via resource fluxes (Fath, 2004; Ulanowicz et al., 2009), offering insights into system health. For example, resource footprint circulation rates reflect node vigor; balanced control-dependency relationships enhance organizational capacity; maintaining metabolic orderliness optimizes resilience thresholds; and niche complementarity indices help analyze co-evolutionary collaboration. There is concern about the approaches used to quantitatively assess the resource flows within a network. A bottom-up approach uses industrial processes to track water flows (Vanham and Bidoglio, 2013), but a top-down approach quantitatively assesses the resource flows within a network (Feng et al., 2011). For example, input-output analysis (IOA), an accepted method for quantifying water flows in a water metabolism system, is preferred over bottom-up approaches because it can link industrial economic data to water consumption using input-output tables and produce a high-resolution view of the networked water flow transactions, helping us to address issues caused within UAs by economic trade, such as water-related resource flows, ecosystem services, and health status (Hubacek and Feng, 2016). However, our ability to carry out a comprehensive and accurate assessment of water system health within UAs is hampered by a lack of high-resolution MRIO data for multi-core multi-level UAs, which has resulted from the poor alignment of statistical standards used for trade data across cities of different levels.

To date, there is little clarity about how the combination of water quantity and water quality influences the health of water metabolism systems in UAs. Cao et al. (2021) were the first to evaluate the health of water networks using an assessment model that focused on water quantity, but excluded water quality. Adequate water quantity and sufficient water quality are essential for the sustainable use of urban water resources (Cai et al., 2023). A water footprint, which incorporates both water quantity and water quality, can be used to assess water flows (Hoekstra and Mekonnen, 2012). Various water footprints have been defined, and the blue water footprint (BWF) and grey water footprint (GWF) have been used to quantify both water quantity and water quality (Chapagain and Hoekstra, 2011; Yu et al., 2022). In previous studies, researchers have focused on either water quantity or water quality when assessing the intensity of resource transfers (Cai et al., 2023; Zhao et al., 2016) and the factors that influenced them (Cai and Guo, 2023; Guan et al., 2014). Some researchers have also simulated and evaluated the performance of metabolism systems using either water quantity or water quality as the independent metabolism medium (He et al., 2020b, 2020a; Liu et al., 2022). The conventional separation of water quantity and quality in current research paradigms makes it difficult to reveal the cascading effects of their synergistic interactions on multiscale metabolism systems, which may lead to ecological cognitive bias in system health assessments. As synergistic variables within regional metabolism system, the mechanisms underlying the interactions between water quantity and water quality remain underexplored. It is imperative to conceptualize water quantity and quality as an integrated metabolism medium and develop a corresponding theoretical framework to elucidate how their synergistic metabolic processes influence system health.

The diagnoses of water metabolism system health at the UA scale are constrained by a) a lack of MRIO tables, which hinders the accurate assessment of water flow within UAs with multi-core and multi-level cities, and b) a limited understanding of how the health of metabolism systems is influenced when water quantity and water quality are combined into a single metabolism medium. To address these issues, we proposed a method for compiling MRIO tables for multi-core multi-level UAs that resolved the methodological limitations associated with assessments of water flow. We created two networks based on MRIO and ENA, one that integrated water quantity and water quality and another for water quantity only, and assessed four attributes of the health of the two networks, namely vigor, organization, resilience, and collaboration. We then tested the method with data from the Guangdong-Hong Kong-Macao Greater Bay Area UA (GBA).

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https://www.sciencedirect.com/science/article/abs/pii/S0043135425008073?via%3Dihub

Public trust in drinking water safety is low globally

Low confidence in water quality is associated with perceptions of public corruption

Source:Northwestern University

Summary:A new study finds more than half of adults surveyed worldwide expect to be seriously harmed by their water within the next two years. The study sought to understand public perceptions of drinking water safety. Because perceptions shape attitudes and behaviors, distrust in water quality has a negative impact on people’s health, nutrition, psychological and economic well-being — even when the water meets safety standards.Share:

    

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A new study finds more than half of adults surveyed worldwide expect to be seriously harmed by their water within the next two years. Led by global health experts at Northwestern University and the University of North Carolina at Chapel Hill, the study sought to understand public perceptions of drinking water safety.

Because perceptions shape attitudes and behaviors, distrust in water quality has a negative impact on people’s health, nutrition, psychological and economic well-being — even when the water meets safety standards.

“If we think our water is unsafe, we will avoid using it,” said Sera Young, professor of anthropology and global health at Northwestern and senior author of the new study.

“When we mistrust our tap water, we buy packaged water, which is wildly expensive and hard on the environment; drink soda or other sugar-sweetened beverages, which is hard on the teeth and the waistline; and consume highly processed prepared foods or go to restaurants to avoid cooking at home, which is less healthy and more expensive,” Young said. “Individuals exposed to unsafe water also experience greater psychological stress and are at greater risk of depression.”

Young is a Morton O. Schapiro Faculty Fellow at the Institute for Policy Research, a faculty fellow at the Paula M. Trienens Institute for Sustainability and Energy, and co-lead of the Making Water Insecurity Visible Working Group at the Buffett Institute for Global Affairs.

Using nationally representative data from 148,585 adults in 141 countries from the 2019 Lloyd’s Register Foundation World Risk Poll, the authors found a high prevalence of anticipated harm from water supply, with the highest in Zambia, the lowest in Singapore and an overall mean of 52.3%.

They also identified key characteristics of those who thought they would be harmed by their drinking water. Women, city dwellers, individuals with more education, and those struggling on their current income were more likely to anticipate being harmed by their drinking water.

The researchers found that, surprisingly, higher corruption perception index scores were the strongest predictor of anticipated harm from drinking water, more so than factors like infrastructure and Gross Domestic Product.

Further, even within countries with consistent access to basic drinking water services, doubts about the safety of water were widespread. This includes the U.S. where 39% of those polled anticipated serious harm from drinking water in the short term.

“Our research highlights that it is imperative both to deliver safe drinking water and to make sure that people have confidence in their water source,” said Joshua Miller, a doctoral student at the UNC Gillings School of Global Public Health and the study’s first author.

The researchers note that it is difficult for consumers to judge the hazards and safety of their water supply because many contaminants are invisible, odorless and tasteless. Without adequate information, many are left to evaluate the safety of their water based on prior experiences, media reports, and personal values and beliefs.

“It’s also possible that people correctly judge the safety of their water,” Young said. “The good people of Flint didn’t trust their water and they were spot on.”

The co-authors suggest actions officials can take to improve public trust around drinking water, including efforts to make testing more readily available, translate test results, replace lead pipes and provide at-home water filters when contaminants are detected, as well as provide improved access to safe drinking water.

“This is the kind of work that can catalyze greater attention and political will to prioritize these services in national development plans and strategies, and get us closer to achieving universal access to safe drinking water,” said Aaron Salzberg, director of the Water Institute at the UNC Gillings School of Global Public Health.

Salzberg previously served as the special coordinator for water resources in the U.S. Department of State, where he was responsible for managing the development and implementation of U.S. foreign policy on drinking water and sanitation, water resources management and transboundary water issues.

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https://www.sciencedaily.com/releases/2024/08/240826182932.htm

Tap vs. Bottled Water: Scientists Reveal Which Contained More Chemical Byproducts

Researchers tested spring, groundwater, and purified bottled waters against local tap to see how treatment shapes the byproducts that emerge — and the differences were striking.

By 

Stacey Leasca

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A plastic bottle of water placed on a surface in sunlight
Credit: Ekaterina Goncharova / Getty Images
  • A new study found that bottled water contains lower levels of disinfection byproducts (DBPs) than chloraminated tap water, averaging less than half the amount found in typical U.S. tap samples.
  • Researchers detected DBPs—including trihalomethanes and haloacetic acids—in all 10 bottled water brands tested, though levels remained relatively low.
  • Spring and groundwater brands tended to have fewer DBPs than purified bottled waters, making them the better choice for minimizing chemical byproducts.

The news hasn’t been great for bottled water fans lately. In January, Food & Wine reported on a new study showing that the more bottled water you drink, the more microplastics you consume, and another study showing that bottled water may contain more bacteria than you might expect. And don’t even get us started on what happens when you leave bottled water in a hot car for too long.

Now, a new study published in the journal Water Research is giving bottled water the silver lining it desperately needs. 

In the new March issue, researchers from the University of South Carolina published findings measuring levels of disinfection byproducts (DBPs) in bottled water compared to chloraminated tap water. The study noted that bottled water often begins as municipal tap water, which is sometimes further disinfected. This process, the researchers added, can form DBPs, chemical compounds created when disinfectants react with natural organic matter.

This Is the Bottled Water Brand Americans Reach for Most, According to New Data

The researchers noted that some of these DBPs are already regulated in bottled water by the U.S. Food and Drug Administration (FDA); however, many more fly under the unregulated radar. To find out which ones may be lurking in your water, the researchers purchased 10 popular brands of bottled water from local stores, including lower-cost “grocery” brands, mid-tier “name” brands, and higher-end “designer” brands. Some of the water was labeled as “purified” (often just code for treated tap water), while others were labeled as spring or groundwater. They also collected a sample of local tap water (treated with chloramine) for comparison with the bottled brands.

The researchers then tested for 64 different DBPs, including 50 unregulated DBPs that had not previously been measured in bottled water. They found that every bottled water sample they tested contained some level of disinfection byproducts, but at relatively low levels, ranging from 0.01 to 22.4 micrograms per liter, or up to about 22 millionths of a gram in roughly 34 ounces of water. By comparison, the tap water sample they analyzed contained 47.3 micrograms per liter, and previous studies suggest U.S. tap water averages closer to 52 micrograms per liter, about double the highest bottled water level measured in this study.

Bottled water vs. tap water: How do DBP levels compare?
Water Type DBP Levels in This Study How It’s Treated What to Know 
Purified bottled water 0.01–22.4 µg/L (some samples near the higher end of the bottled range) Often municipal tap water that has been further treated (e.g., reverse osmosis, distillation, or carbon filtration) May still contain DBPs formed during disinfection. Levels varied by lot. 
Spring/groundwater bottled water Generally lower overall DBPs than purified brands Sourced from underground aquifers; may be disinfected but often undergoes less treatment than purified water Showed lower DBP levels in this study, but not DBP-free. 
Chloraminated tap water (sample) 47.3 µg/L Treated with chloramine to kill pathogens Higher DBPs than any bottled sample tested, but within federal regulatory limits. 
Average U.S. tap water (prior research) ~52 µg/L Typically chlorinated or chloraminated Federal EPA limit for total trihalomethanes is 80 µg/L. 

Here’s how disinfection byproduct (DBP) levels in bottled water brands stack up against chloraminated tap water samples and prior U.S. averages.

And a hot tip: If you’re hoping to score the bottled water with the lowest levels of DBPs, go for spring and groundwater, which showed lower overall DBPs than purified brands.

As for which byproducts they identified, the team reported that trihalomethanes and haloacetic acids had the highest concentrations. Both are common DBPs that form when chlorine reacts with organic matter in water. (However, some studies have linked long-term exposure at high levels to an increased risk of certain cancers.) The researchers also found several unregulated DBPs, including dibromoacetonitrile, which is carcinogenic. 

https://www.foodandwine.com/embed?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DL7qnquywcZU&id=mntl-sc-block_20-0-iframe&options=e30%3D&docId=11909742

The one thing the team couldn’t do was say with certainty that there is a “safest” brand of water, because DBP levels varied from lot to lot, making brand-level comparisons impossible. As for what’s next, the team hopes their work can inform future studies tracking these DBPs over time to see how they develop as water sits on the shelf.

Tap Water Disinfection May Form Far More Chemical Byproducts Than Regulators Track, Study Finds

Bottom line: Bottled water isn’t DBP-free — but it may contain lower levels than some tap water. If you’re concerned, spring water and proper storage are your best bets. And as always, balance convenience, cost, and environmental impact before stocking up.

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https://www.foodandwine.com/tap-vs-bottled-water-disinfection-byproducts-usc-study-2026-11909742

New solutions to keep drinking water safe as pesticide use skyrockets worldwide

Source:University of South Australia

Summary:Water scientists have proposed a more effective method of removing organic pesticides from drinking water, reducing the risk of contamination and potential health problems.Share:

    

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Water scientists from Australia and China have proposed a more effective method of removing organic pesticides from drinking water, reducing the risk of contamination and potential health problems.

A 62% rise in global pesticide use in the past 20 years has escalated fears that many of these chemicals could end up in our waterways, causing cancer.

Powdered activated carbon (PAC) is currently used to remove organic pesticides from drinking water, but the process is costly, time consuming and not 100% effective.

University of South Australia water researcher Professor Jinming Duan has collaborated with his former PhD student, Dr Wei Li of Xi’an University of Architecture & Technology and Chinese colleagues in a series of experiments to improve the process.

The researchers found that reducing the PAC particles from the existing commercial size of 38 μm (one millionth of a metre) to 6 μm, up to 75% less powder was needed to remove six common pesticides, achieving significant water treatment savings.

At 6 μm, the PAC particles are still large enough to be filtered out after the adsorption process, ensuring they do not end up in the drinking water after toxic pesticides are removed.

Prof Duan says pollutants in our waterways are projected to increase in coming decades as the world’s population and industrial development grows.

“It’s therefore critical that we develop cost-effective treatment processes to ensure our waterways remain safe,” he says.

Their findings have been published in the journal Chemosphere.

“Pesticides cannot be removed using conventional water treatment processes such as flocculation, sedimentation and filtration. Powdered activated carbon does the job, but the existing methods have limitations. Our study has identified how we can make this process more efficient.”

Approximately 3.54 million metric tons of pesticides were applied to agricultural crops worldwide in 2021, according to the Statista Research Department.

Worryingly, despite efforts to increase their efficiency, it is estimated that only 10% of pesticides reach their target pests, with most of the chemicals remaining on plant surfaces or entering the environment, including the soil, waterways and atmosphere.

Toxicological studies have suggested that long-term exposure to low levels of pesticides — primarily through diet or drinking water — could increase the risks of cancer and other diseases.

“This is why it is important to reduce their levels to as low as feasibly possible,” Prof Duan says.

The researchers also hope to explore how super-fine activated carbon could be used to remove toxic polyfluoroalkyl substances (PFAS) and perfluorinated compounds (PFCs) found in many consumer products, which have been linked to adverse health impacts.

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https://www.sciencedaily.com/releases/2024/07/240711111526.htm

Water chlorination levels in US and EU likely increase cancer risk, study finds

This article is more than 1 year old

Bladder cancer risk increased 33% and colorectal cancer by 15% in using chlorine to disinfect water

Tom Perkins Mon 17 Feb 2025 06.00 ESTShare

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Chlorinating drinking water at levels common in the United States and European Union probably increases the risk of several cancers, a new analysis of recent research from across the globe finds.

The process of disinfecting water with chlorine creates trihalomethane (THM) byproducts, which are found in virtually all public drinking water systems across the US and EU – nearly 300 million people in the US have concerning levels in their water, by one estimate.

While the chlorination process is a “cheap, effective, and readily available” method for killing organisms and infectious disease, it comes with trade-offs, the study’s authors wrote, including a 33% increased risk of bladder cancer and 15% increased risk of colorectal cancer.

“What we see is alarming and we need some more high quality studies,” Emilie Helte, a lead author with Karolinska Institutet in Sweden, said.

An irrigation ditch

The process of disinfecting water is an essential public health measure that dramatically increased life expectancy when the US began chlorinating drinking water in the early 1900s because it significantly reduced microbial infections and waterborne illnesses, like cholera and typhoid fever.

It wasn’t until the 1970s that researchers discovered the process came with consequences. When chlorine is added to water, it reacts with organic compounds, like decaying plant material, to create any number of hundreds of potentially toxic byproducts.

Some of the most common – chloroform, bromoform, bromodichloromethane, and chlorodibromomethane – are known to be genotoxic and carcinogenic to rats.

The US and EU set limits on byproducts at 80 parts per billion (ppb) and 100ppb, respectively, but the new research points to increased cancer risks at levels as low as 40ppb, which is around what they have been found at in New York City. The EPA reports levels are typically in the 40 to 60ppb range and the public health advocacy non-profit Environmental Working Group estimates the safe level at 0.15ppb.

The new meta study is among the most emphatic evidence because it looked at data from about 30 studies and 90,000 participants, and found men were more at risk than women. The authors only looked at bladder and colorectal impacts because there is a dearth of research on other cancers. Researchers are not sure why the chemicals seem to most frequently target the large intestine and bladder, Helte said.

The problem creates a difficult tension for regulators. Surface water typically has higher THM levels than groundwater because it has more organisms and organic matter for the disinfectants to react with. Water utilities could clean some of the organic matter out of the water before disinfecting, and it is also potentially possible to lower the amount of chlorine added, but “it’s really important not to use too little disinfectant”, Helte said.

Alternatives such as treating the water with ultraviolet light or installing new filtration systems are also possible, but are expensive, Helte said.

She stressed that people should continue to drink municipal water. Granulated activated carbon is among the best filtration systems that can be used at home to remove the contaminants.

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https://www.theguardian.com/us-news/2025/feb/17/water-chlorination-cancer-risk-us-eu?

Twenty-year study shows cleaner water slashes cancer and heart disease deaths

Source:Columbia University’s Mailman School of Public Health

Summary:A 20-year project in Bangladesh reveals that lowering arsenic levels in drinking water can slash death rates from major chronic diseases. Participants who switched to safer wells had the same risk levels as people who were never heavily exposed. The researchers tracked individual water exposure with detailed urine testing. Their results show how quickly health improves once contaminated water is replaced.Share:

    

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Safer Wells Save Lives in Bangladesh
Cleaner water dramatically reduces chronic disease deaths, even for those exposed to arsenic for years. Credit: Shutterstock

A large 20-year investigation following nearly 11,000 adults in Bangladesh found that reducing arsenic in drinking water was tied to as much as a 50 percent drop in deaths from heart disease, cancer and several other chronic illnesses. The research offers the strongest long-term evidence so far that lowering arsenic exposure can reduce mortality, even for people who lived with contaminated water for many years. These results appear in JAMA.

Scientists from Columbia University, the Columbia Mailman School of Public Health and New York University led the analysis, which addresses a widespread health concern. Naturally occurring arsenic in groundwater remains a significant challenge across the world. In the United States, more than 100 million people depend on groundwater that can contain arsenic, particularly those using private wells. Arsenic continues to be one of the most common chemical contaminants in drinking water.

“We show what happens when people who are chronically exposed to arsenic are no longer exposed,” said co-lead author Lex van Geen of the Lamont-Doherty Earth Observatory, part of the Columbia Climate School. “You’re not just preventing deaths from future exposure, but also from past exposure.”

Two Decades of Data Strengthen the Evidence

Co-lead author Fen Wu of NYU Grossman School of Medicine said the findings offer the clearest proof yet of the connection between lowering arsenic exposure and reduced mortality risk. Over the course of two decades, the researchers closely tracked participants’ health and repeatedly measured arsenic through urine samples, which strengthened the precision of their analysis.

“Seeing that our work helped sharply reduce deaths from cancer and heart disease, I realized the impact reaches far beyond our study to millions in Bangladesh and beyond now drinking water low in arsenic,” said Joseph Graziano, Professor Emeritus at Columbia Mailman School of Public Health and principal investigator of the NIH-funded program. “A 1998 New York Times story first brought us to Bangladesh. More than two decades later, this finding is deeply rewarding. Public health is often the ultimate delayed gratification.”

Clear Drop in Risk When Arsenic Exposure Falls

People whose urinary arsenic levels fell from high to low had mortality rates that matched those who had consistently low exposure for the entire study. The size of the drop in arsenic was closely tied to how much mortality risk declined. Those who continued drinking high-arsenic water did not show any reduction in chronic disease deaths.

Arsenic naturally accumulates in groundwater and has no taste or smell, meaning people can drink contaminated water for years without knowing it. In Bangladesh, an estimated 50 million people have consumed water exceeding the World Health Organization’s guideline of 10 micrograms per liter. The WHO has described this as the largest mass poisoning in history.

From 2000 to 2022, the Health Effects of Arsenic Longitudinal Study (HEALS) monitored thousands of adults in Araihazar, Bangladesh. The project tested more than 10,000 wells in a region where many families rely on shallow tube wells with arsenic levels ranging from extremely low to dangerously high.

Researchers periodically measured arsenic in participants’ urine, a direct marker of internal exposure, and recorded causes of death. These detailed data allowed the team to compare long-term health outcomes for people who reduced their exposure with those who remained highly exposed.

Community Efforts Created a Natural Comparison Group

Throughout the study period, national and local programs labeled wells as safe or unsafe based on arsenic levels. Many households switched to safer wells or installed new ones, while others continued using contaminated water. This created a natural contrast that helped researchers understand the effects of reducing exposure.

Arsenic exposure decreased substantially in Araihazar during the study. The concentration in commonly used wells fell by about 70 percent as many families sought cleaner water sources. Urine tests confirmed a corresponding decline in internal exposure, averaging a 50 percent reduction that persisted through 2022.

Reduced Exposure Brings Lasting Health Benefits

These trends held true even after researchers accounted for differences in age, smoking and socioeconomic factors. Participants who remained highly exposed, or whose exposure rose over time, continued to face significantly higher risks of death from chronic diseases.

The researchers compared the health benefits of lowering arsenic to quitting smoking. The risks do not disappear immediately but drop gradually as exposure decreases.

In Bangladesh, well testing, labeling unsafe sources, drilling private wells and installing deeper government wells have already improved water safety for many communities.

“Our findings can now help persuade policymakers in Bangladesh and other countries to take emergency action in arsenic ‘hot spots’,” said co-author Kazi Matin Ahmed of the University of Dhaka.

To reach more households, the research team is collaborating with the Bangladeshi government to make well data easier to access. They are piloting NOLKUP (“tubewell” in Bangla), a free mobile app created from more than six million well tests. Users can look up individual wells, review arsenic levels and depths, and locate nearby safer options. The tool also helps officials identify communities that need new or deeper wells.

Clean Water Investments Can Save Lives

The study shows that health risks can fall even for people who were exposed to arsenic for years. This highlights an important opportunity: investing in clean water solutions can save lives within a single generation.

“Sustainable funding to support the collection, storage and maintenance of precious samples and data over more than 20 years have made this critically important work possible,” said Ana Navas-Acien, MD, PhD, Professor and Chair of Environmental Health Sciences at Columbia Mailman School of Public Health. “Science is difficult and there were challenges and setbacks along the way, but we were able to maintain the integrity of the samples and the data even when funding was interrupted, which has allowed us to reveal that preventing arsenic exposure can prevent disease.”

The study team included researchers from Columbia University’s Mailman School of Public Health, the New York University Grossman School of Medicine, Lamont-Doherty Earth Observatory, Boston University School of Public Health, the Department of Geology at the University of Dhaka and the Institute for Population and Precision Health at the University of Chicago.

The HEALS project was launched by Columbia University through the National Institute of Environmental Health Sciences’ Superfund Research Program, with most U.S. collaborators based at Columbia when the study began.

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https://www.sciencedaily.com/releases/2025/11/251127010327.htm?

EWG: Reducing multiple tap water contaminants may prevent over 50,000 cancer cases

Study shows health benefits of tackling arsenic, chromium-6 and other pollutants at once

WASHINGTON – Drinking water treatment that pursues a multi-contaminant approach, tackling several pollutants at once, could prevent more than 50,000 lifetime cancer cases in the U.S., finds a new peer-reviewed study by the Environmental Working Group.

The finding challenges the merits of regulating one tap water contaminant at a time, the long-standing practice of states and the federal government. 

In the paper, published in the journal Environmental Research, EWG scientists analyzed more than a decade of data from over 17,000 community water systems. They found that two cancer-causing chemicals – arsenic and hexavalent chromium, or chromium-6 – often appear together in systems and can be treated using the same technologies. 

If water systems with chromium-6 contamination also reduce arsenic levels to a range from 27% to 42%, it could avoid up to quadruple the number of cancer cases compared to just lowering chromium-6 levels alone, the study finds. 

Treatment of drinking water for one contaminant, such as nitrate, has advantages for public health. But tackling multiple contaminants at once increases the health benefits. And those benefits can expand along with the number of pollutants treated at the same time. 

 “Drinking water is contaminated mostly in mixtures, but our regulatory system still acts like they appear one at a time,” said Tasha Stoiber, Ph.D., a senior scientist at EWG and lead author of the study. “This research shows that treating multiple contaminants together could prevent tens of thousands of cancer cases.”

Chromium-6 and arsenic are commonly found in drinking water across the U.S. Chromium-6 has been found in drinking water served to 264 million Americans. 

“Addressing co-occurring contaminants is scientifically the most sound approach, as well as an efficient way to protect public health,” added Stoiber.

In California alone, nearly eight out of 10 preventable cancer cases are linked to arsenic exposure.

Arizona, California and Texas bear the highest burden of arsenic pollution and would gain the most from multi-contaminant water treatment efforts.

Health risks of water contaminants

Toxic chemicals like chromium-6, arsenic and nitrate pose the greatest risks to children, pregnant people and those living in smaller communities served by water systems relying on groundwater. Systems serving these populations often rely on only one water source and the smaller communities lack the resources to demand better treatment, despite facing the most serious health harms.

Chromium-6 

This cancer-causing chemical made infamous by the film “Erin Brockovich” is linked to serious health risks. Studies show even low levels in drinking water can increase the risk of stomach cancer, liver damage and reproductive harm. 

In 2008, the National Toxicology Program found much higher rates of stomach and intestinal tumors in lab animals exposed to chromium-6 in water. California researchers later confirmed a higher risk of stomach cancer in workers who had been exposed.

The Environmental Protection Agency does not limit the amount of chromium-6 in drinking water. It does regulate total chromium, which includes chromium-6 and the mostly harmless chromium-3. Total chromium is set at 100 parts per billion, or ppb, for drinking water.

Arsenic

Arsenic is found in drinking water in all 50 states. It occurs in natural deposits and as a result of human activities such as mining and pesticide use. Long-term exposure is linked to serious health issues, including bladder, lung and skin cancers, as well as cardiovascular and developmental harm.

The legal federal limit for arsenic in drinking water is 10 ppb, set in 2001 based on outdated cost estimates for treatment, not on what’s safest for health. California’s public health goal is just 0.004 ppb, the level scientists say would pose no significant cancer risk over a lifetime.

Arsenic can also contaminate certain foods, especially rice and rice-based products, making clean water standards all the more important for reducing overall exposure.

Nitrate 

Nitrate is one of the most common drinking water contaminants, especially downstream from agricultural areas where it enters water supplies through fertilizer and manure runoff. It’s also found in private wells, often near farms or septic systems.

Exposure to nitrate in drinking water is linked to serious health risks, including colorectal and ovarian cancer, very preterm birth, low birth weight, and neural tube defects. 

The EPA set the nitrate limit at 10 parts per million in 1992 to prevent “blue baby syndrome.” But it hasn’t updated the standard in over 30 years. New research shows cancer and birth-related harms can occur at levels far below the legal limit. European studies have found increased cancer risks at nitrate levels more than 10 times lower than the EPA limit.

“Ensuring clean drinking water for all communities is about fairness and equity,” said Sydney Evans, MPH, EWG senior science analyst and a co-author of the new study. 

“Communities in the U.S. that rely on groundwater are often affected by these contaminants. New water treatment technologies offer a chance to improve water quality overall. This strengthens the case for action and investment.”

Call for smarter water rules

Federal regulations still evaluate the cost and benefit of water treatment on a one-contaminant basis, a model EWG’s report calls outdated and inefficient. 

Small and rural water systems often face the steepest per-person costs to implement new treatment technologies. But they’re among the most exposed to pollutants and associated risks.

These systems frequently lack the funding and technical support to upgrade aging infrastructure, leaving residents exposed to serious health threats. This level of vulnerability calls for new strategies for these communities – a  boost in funding coupled with more effective regulations.

For example, nitrate, often found alongside chromium-6 in drinking water, represents a major but overlooked opportunity for health protection.

“Nitrate pollution is a public health crisis, particularly in the Midwest but also across the country,” said Anne Schechinger, EWG’s Midwest director. “The federal nitrate limit was set decades ago to prevent infant deaths, but we now know see cancer and birth complications at levels of nitrate far below that outdated standard.

“Even lowering nitrate slightly could prevent hundreds of cancer cases and save tens of millions of dollars in health care costs, especially when paired with treatment for other contaminants, such as chromium-6 and arsenic,” she said. “There’s a real cost to inaction – our health and our wallets can’t afford to wait for better treatment.”

Proven technologies like ion exchange and reverse osmosis, already used today, can remove nitrate, chromium-6 and arsenic from drinking water at the same time. 

“This is about more than clean water – it’s about protecting health and advancing equity,” said David Andrews, Ph.D., acting chief science officer at EWG. “We have the engineering solutions to fix the broken drinking water system in the U.S., but we need state and federal policies to reflect the reality people face when they turn on the tap.”

Consumers concerned about chemicals in their tap water can install a water filter to help reduce their exposure to contaminants. The home filter system that’s most effective for removing chromium-6, arsenic and nitrate from water is reverse osmosis. Ion exchange technology is another option for reducing levels of these contaminants.

EWG’s water filter guide contains more information about available options. It is crucial to change water filters on time. Old filters aren’t safe, since they harbor bacteria and let contaminants through.

People can also search EWG’s national Tap Water Database to learn which contaminants are detected in their tap water.

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The Environmental Working Group is a nonprofit, non-partisan organization that empowers people to live healthier lives in a healthier environment. Through research, advocacy and unique education tools, EWG drives consumer choice and civic action.

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https://www.ewg.org/news-insights/news-release/2025/07/ewg-reducing-multiple-tap-water-contaminants-may-prevent-over?

Integrating water quality and water quantity to diagnose the health of water metabolism systems in multi-core multi-level urban agglomerations

Author links open overlay panelYing Yang a1

, Jing Wen a1

, Meirong Su b

, Qionghong Chen cShow moreAdd to MendeleyShareCite

https://doi.org/10.1016/j.watres.2025.123899Get rights and content

Highlights

  • •The MRIO table was compiled for a multi-core multi-level urban agglomeration.
  • •A diagnostic framework was established by coupling ENA and MRIO approaches.
  • •Water quantity-water quality linkage was considered in the diagnostic framework.
  • •The IWMN was less vigorous and less organized than the QWMN.
  • •The IWMN tended slightly towards mutualism but had more negative collaborations.

Abstract

Urban agglomerations (UAs) are compelled to scrutinize the health of their water systems as the frequency of water crises increases. An urban water system’s health is closely related to metabolism processes. To date, water systems in multi-core multi-level UAs have not been analyzed using water quantity and water quality because of methodological constraints. To address this research gap, we developed an integrated water quality–water quantity model for diagnosing water metabolism systems that could process nested multi-region input-output (MRIO) tables. We coupled the MRIO tables and established two networks, an integrated water quantity–quality metabolism network (IWMN) and a water quantity metabolism network (QWMN). We tested the two networks with data from the Guangdong-Hong Kong-Macao UA and assessed four aspects of the networks’ health, namely vigor, organization, resilience, and collaboration, using ecological network analysis. We discovered that IWMN exhibited lower vigor (internal circulation 10.4 %) and organization dominated by dependency (total contribution intensity σ = -23) compared to the QWMN. Polity-driven disparities shaped the robustness distribution, while a mutualism tendency coexisted with a complex exploitation relationship (52.4 %), particularly in the core large-sized city of Hong Kong, where 58 new competitive pairs emerged. Thus, we recommend prioritizing Guangdong-Hong Kong-Macao trade optimization for high-water-content products to enhance system health.

Graphical abstract

Image, graphical abstract

Introduction

The surface water deficit experienced in 482 of the world’s largest cities is projected to reach 6.75 million tons by 2050 because of an imbalance between the water supply and the demand (Flörke et al., 2018). This trend has prompted growing interest in resource allocation and environmental protection within urban agglomerations (UAs). UAs are composed of multiple geographically adjacent cities with diverse sizes and characteristics (Fang et al., 2015). Diverse UAs with multi-core structures (classified by comprehensive urban engine functions) and multi-level systems (quantified by social indicators) face challenges due to high heterogeneity in population size and spatial resource allocation (Han et al., 2019; Chirigati, 2022; Zhao et al., 2021). Water quantity and water quality are important attributes of water resources. Changes in the water quantity caused by a lack of rainfall or heavy rainfall events affect the water quality by concentrating pollutants or diluting. Conversely, degraded water quality diminishes the availability of water resources (Li et al., 2023) and has direct effects on urban aquatic ecosystems (Liu and Yang, 2012). Therefore, to optimize water management in multi-core multi-level UAs, we need to know more about the combined effects of water quality and water quantity on the water resources.

When optimizing water management in urban areas, the water metabolism mechanism of the system should be analyzed, and key issues should be identified (Cao et al., 2021; He et al., 2020b; Liu et al., 2022). The concept of water metabolism originates from urban metabolism (Wolman, 1965), which describes water cycle processes (e.g., water input, output, and storage) driven by social activities in different cities (Wang and Chen, 2010). This concept can effectively identify hidden risks resulting from the allocation of social resources—such as population, industry and environment within UAs, thus challenging the traditional multilevel paradigm of urban water management. In assessing the health of water systems based on water metabolism mechanisms, processes analogous to those in natural ecosystems, such as vigor and collaboration (Y.J. Yang et al., 2020; Zhu et al., 2020), sustained and stable organization, and adaptability to external pressures (Yan et al., 2014), are employed. However, to date, most research has primarily focused on the efficiency of consumptive activities (Nishimura et al., 2021; Qi et al., 2021; Xu et al., 2020), while ignoring the underlying water metabolism processes.

Network methods are effective for characterizing critical resource metabolism processes (Liang et al., 2020). Ecological Network Analysis (ENA) (Hannon B, 1973) quantifies metabolic features via resource fluxes (Fath, 2004; Ulanowicz et al., 2009), offering insights into system health. For example, resource footprint circulation rates reflect node vigor; balanced control-dependency relationships enhance organizational capacity; maintaining metabolic orderliness optimizes resilience thresholds; and niche complementarity indices help analyze co-evolutionary collaboration. There is concern about the approaches used to quantitatively assess the resource flows within a network. A bottom-up approach uses industrial processes to track water flows (Vanham and Bidoglio, 2013), but a top-down approach quantitatively assesses the resource flows within a network (Feng et al., 2011). For example, input-output analysis (IOA), an accepted method for quantifying water flows in a water metabolism system, is preferred over bottom-up approaches because it can link industrial economic data to water consumption using input-output tables and produce a high-resolution view of the networked water flow transactions, helping us to address issues caused within UAs by economic trade, such as water-related resource flows, ecosystem services, and health status (Hubacek and Feng, 2016). However, our ability to carry out a comprehensive and accurate assessment of water system health within UAs is hampered by a lack of high-resolution MRIO data for multi-core multi-level UAs, which has resulted from the poor alignment of statistical standards used for trade data across cities of different levels.

To date, there is little clarity about how the combination of water quantity and water quality influences the health of water metabolism systems in UAs. Cao et al. (2021) were the first to evaluate the health of water networks using an assessment model that focused on water quantity, but excluded water quality. Adequate water quantity and sufficient water quality are essential for the sustainable use of urban water resources (Cai et al., 2023). A water footprint, which incorporates both water quantity and water quality, can be used to assess water flows (Hoekstra and Mekonnen, 2012). Various water footprints have been defined, and the blue water footprint (BWF) and grey water footprint (GWF) have been used to quantify both water quantity and water quality (Chapagain and Hoekstra, 2011; Yu et al., 2022). In previous studies, researchers have focused on either water quantity or water quality when assessing the intensity of resource transfers (Cai et al., 2023; Zhao et al., 2016) and the factors that influenced them (Cai and Guo, 2023; Guan et al., 2014). Some researchers have also simulated and evaluated the performance of metabolism systems using either water quantity or water quality as the independent metabolism medium (He et al., 2020b, 2020a; Liu et al., 2022). The conventional separation of water quantity and quality in current research paradigms makes it difficult to reveal the cascading effects of their synergistic interactions on multiscale metabolism systems, which may lead to ecological cognitive bias in system health assessments. As synergistic variables within regional metabolism system, the mechanisms underlying the interactions between water quantity and water quality remain underexplored. It is imperative to conceptualize water quantity and quality as an integrated metabolism medium and develop a corresponding theoretical framework to elucidate how their synergistic metabolic processes influence system health.

The diagnoses of water metabolism system health at the UA scale are constrained by a) a lack of MRIO tables, which hinders the accurate assessment of water flow within UAs with multi-core and multi-level cities, and b) a limited understanding of how the health of metabolism systems is influenced when water quantity and water quality are combined into a single metabolism medium. To address these issues, we proposed a method for compiling MRIO tables for multi-core multi-level UAs that resolved the methodological limitations associated with assessments of water flow. We created two networks based on MRIO and ENA, one that integrated water quantity and water quality and another for water quantity only, and assessed four attributes of the health of the two networks, namely vigor, organization, resilience, and collaboration. We then tested the method with data from the Guangdong-Hong Kong-Macao Greater Bay Area UA (GBA).

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https://www.sciencedirect.com/science/article/abs/pii/S0043135425008073?via%3Dihub

Twenty-year study shows cleaner water slashes cancer and heart disease deaths

Date:November 27, 2025

Source:Columbia University’s Mailman School of Public Health

Summary:A 20-year project in Bangladesh reveals that lowering arsenic levels in drinking water can slash death rates from major chronic diseases. Participants who switched to safer wells had the same risk levels as people who were never heavily exposed. The researchers tracked individual water exposure with detailed urine testing. Their results show how quickly health improves once contaminated water is replaced.Share:

    

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Safer Wells Save Lives in Bangladesh
Cleaner water dramatically reduces chronic disease deaths, even for those exposed to arsenic for years. Credit: Shutterstock

A large 20-year investigation following nearly 11,000 adults in Bangladesh found that reducing arsenic in drinking water was tied to as much as a 50 percent drop in deaths from heart disease, cancer and several other chronic illnesses. The research offers the strongest long-term evidence so far that lowering arsenic exposure can reduce mortality, even for people who lived with contaminated water for many years. These results appear in JAMA.

Scientists from Columbia University, the Columbia Mailman School of Public Health and New York University led the analysis, which addresses a widespread health concern. Naturally occurring arsenic in groundwater remains a significant challenge across the world. In the United States, more than 100 million people depend on groundwater that can contain arsenic, particularly those using private wells. Arsenic continues to be one of the most common chemical contaminants in drinking water.

“We show what happens when people who are chronically exposed to arsenic are no longer exposed,” said co-lead author Lex van Geen of the Lamont-Doherty Earth Observatory, part of the Columbia Climate School. “You’re not just preventing deaths from future exposure, but also from past exposure.”

Two Decades of Data Strengthen the Evidence

Co-lead author Fen Wu of NYU Grossman School of Medicine said the findings offer the clearest proof yet of the connection between lowering arsenic exposure and reduced mortality risk. Over the course of two decades, the researchers closely tracked participants’ health and repeatedly measured arsenic through urine samples, which strengthened the precision of their analysis.

“Seeing that our work helped sharply reduce deaths from cancer and heart disease, I realized the impact reaches far beyond our study to millions in Bangladesh and beyond now drinking water low in arsenic,” said Joseph Graziano, Professor Emeritus at Columbia Mailman School of Public Health and principal investigator of the NIH-funded program. “A 1998 New York Times story first brought us to Bangladesh. More than two decades later, this finding is deeply rewarding. Public health is often the ultimate delayed gratification.”

Clear Drop in Risk When Arsenic Exposure Falls

People whose urinary arsenic levels fell from high to low had mortality rates that matched those who had consistently low exposure for the entire study. The size of the drop in arsenic was closely tied to how much mortality risk declined. Those who continued drinking high-arsenic water did not show any reduction in chronic disease deaths.

Arsenic naturally accumulates in groundwater and has no taste or smell, meaning people can drink contaminated water for years without knowing it. In Bangladesh, an estimated 50 million people have consumed water exceeding the World Health Organization’s guideline of 10 micrograms per liter. The WHO has described this as the largest mass poisoning in history.

From 2000 to 2022, the Health Effects of Arsenic Longitudinal Study (HEALS) monitored thousands of adults in Araihazar, Bangladesh. The project tested more than 10,000 wells in a region where many families rely on shallow tube wells with arsenic levels ranging from extremely low to dangerously high.

Researchers periodically measured arsenic in participants’ urine, a direct marker of internal exposure, and recorded causes of death. These detailed data allowed the team to compare long-term health outcomes for people who reduced their exposure with those who remained highly exposed.

Community Efforts Created a Natural Comparison Group

Throughout the study period, national and local programs labeled wells as safe or unsafe based on arsenic levels. Many households switched to safer wells or installed new ones, while others continued using contaminated water. This created a natural contrast that helped researchers understand the effects of reducing exposure.

Arsenic exposure decreased substantially in Araihazar during the study. The concentration in commonly used wells fell by about 70 percent as many families sought cleaner water sources. Urine tests confirmed a corresponding decline in internal exposure, averaging a 50 percent reduction that persisted through 2022.

Reduced Exposure Brings Lasting Health Benefits

These trends held true even after researchers accounted for differences in age, smoking and socioeconomic factors. Participants who remained highly exposed, or whose exposure rose over time, continued to face significantly higher risks of death from chronic diseases.

The researchers compared the health benefits of lowering arsenic to quitting smoking. The risks do not disappear immediately but drop gradually as exposure decreases.

In Bangladesh, well testing, labeling unsafe sources, drilling private wells and installing deeper government wells have already improved water safety for many communities.

“Our findings can now help persuade policymakers in Bangladesh and other countries to take emergency action in arsenic ‘hot spots’,” said co-author Kazi Matin Ahmed of the University of Dhaka.

To reach more households, the research team is collaborating with the Bangladeshi government to make well data easier to access. They are piloting NOLKUP (“tubewell” in Bangla), a free mobile app created from more than six million well tests. Users can look up individual wells, review arsenic levels and depths, and locate nearby safer options. The tool also helps officials identify communities that need new or deeper wells.

Clean Water Investments Can Save Lives

The study shows that health risks can fall even for people who were exposed to arsenic for years. This highlights an important opportunity: investing in clean water solutions can save lives within a single generation.

“Sustainable funding to support the collection, storage and maintenance of precious samples and data over more than 20 years have made this critically important work possible,” said Ana Navas-Acien, MD, PhD, Professor and Chair of Environmental Health Sciences at Columbia Mailman School of Public Health. “Science is difficult and there were challenges and setbacks along the way, but we were able to maintain the integrity of the samples and the data even when funding was interrupted, which has allowed us to reveal that preventing arsenic exposure can prevent disease.”

The study team included researchers from Columbia University’s Mailman School of Public Health, the New York University Grossman School of Medicine, Lamont-Doherty Earth Observatory, Boston University School of Public Health, the Department of Geology at the University of Dhaka and the Institute for Population and Precision Health at the University of Chicago.

The HEALS project was launched by Columbia University through the National Institute of Environmental Health Sciences’ Superfund Research Program, with most U.S. collaborators based at Columbia when the study began.

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https://www.sciencedaily.com/releases/2025/11/251127010327.htm?

Over 38,000 Gallons of Water Have Been Recalled Due to ‘Foreign Black Substance’ Contamination

The gallon jugs were shipped to store locations in six states nationwide

By Moná Thomas 

Published on January 15, 2026 11:55AM EST

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water bottles on an automated conveyor belt, Bottled water production line
water bottles on an automated conveyor belt, Bottled water production line.Credit : cofotoisme/Getty

NEED TO KNOW

  • 38,043 gallons of Meijer Steam Distilled Water have been recalled
  • The enforcement reports cite “floating black foreign substance” contamination for the recall
  • The company has yet to issue a statement confirming the nature of the foreign substance

More than 38,000 gallons of bottled water have been recalled after an Enforcement Report from the U.S. Food and Drug Administration (FDA) revealed a “floating black foreign substance” appearing inside gallon-sized jugs.

According to a notice published by the FDA, the recall involves Meijer Steam Distilled Water, which is sold in one-gallon plastic containers with red caps. Meijer voluntarily initiated the recall in November 2025, and it remains ongoing as officials continue to review the issue. In total, 38,043 gallons of the product are affected.

Meijer Distilled Water, Recall
Meijer Distilled Water, Recall.Meijer 

The affected jugs can be identified by a best-by date of Oct. 4, 2026, along with lot code 39-222 #3 and a UPC code of 041250841197. Meijer item codes tied to the recall include Product ID 472859 and Item Code 477910.

The recalled water was distributed to Meijer stores across Illinois, Indiana, Kentucky, Michigan, Ohio and Wisconsin. Consumers who purchased distilled water in those states are urged to check their containers carefully.

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According to the FDA notice, the issue stems from the presence of a black substance floating inside the water, though the exact source and composition of the material have not been publicly identified. The agency has not yet assigned a recall classification, which typically indicates how serious a potential health risk may be.

Meijer did not initially respond to PEOPLE’s request for comment.

Distilled water is often used for more than just drinking. Many consumers rely on it for medical devices, such as CPAP machines, according to Verywell Health, as well as for infant formula preparation and sinus rinses, where water purity is especially important. Because of that, officials say consumers should stop using the recalled water immediately, even if no health issues are apparent.

At this time, no illnesses or injuries have been reported in connection with the recalled product. Still, the FDA advises anyone who has the affected water to either dispose of it safely or return it to a Meijer store for a refund or replacement.

The FDA continues to monitor the recall and has not provided additional details about how the contamination occurred. Consumers are encouraged to review any distilled water they have on hand and follow recall guidance to avoid potential exposure.

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https://people.com/over-38-000-gallons-of-water-have-been-recalled-due-to-foreign-black-substance-contamination-11885997?