In real-world testing, researchers found that a carbon-based material placed underground sharply lowered PFAS in groundwater and required minimal maintenance.
How to Make Spanakopita-Inspired Potato Crust QuicheClose
Credit: Viktoriya Skorikova / Getty Images
Scientists from Brown University, the University of Minnesota, and the U.S. Navy found that injecting colloidal carbon into contaminated soil can trap PFAS chemicals underground, dramatically reducing contamination.
In field tests, PFAS concentrations fell from over 50,000 nanograms per liter to undetectable levels within 10 months, capturing both long- and short-chain PFAS compounds.
The approach could cost less than half as much as current cleanup methods and require minimal maintenance, offering a sustainable solution for communities dealing with PFAS pollution.
Over decades, per- and polyfluoroalkyl substances (PFAS) have slowly woven their way into our daily lives, without most of us ever noticing. They’re the stuff that prevents your eggs from sticking to the frying pan, waterproofs your jackets, allows makeup to last an entire day, and keeps those fast-food wrappers grease-resistant.
They’re also the stuff that earned the unsettling nickname “forever chemicals” thanks to carbon-fluorine bonds so strong that once these chemicals enter the environment, they tend to stay there. Forever. And that durability has become a serious problem. Scientists are increasingly recognizing that PFAS may cause a range of health issues, even as these chemicals have been detected in groundwater near military bases, airports, industrial sites, and municipal water systems across the United States. Cleaning them up has proven frustratingly difficult, expensive, and often temporary. Public-facing advice has often focused on avoiding products that contain PFAS or relying on above-ground water filtration, which requires almost constant upkeep. But now a few savvy researchers say they may soon have a solution for that, too.
Researchers from Brown University and the University of Minnesota, alongside industry partners and the U.S. Navy, tested whether an ultrafine carbon material could be injected directly into contaminated soil to trap PFAS in place. Their findings, published inThe Journal of Hazardous Materials, show that it may be a wild enough idea to work.
The team tested an activated carbon material known as “colloidal carbon,” which acts like a microscopic sponge that can trap PFAS chemicals underground. They began by trialing it in lab conditions, collecting soil from a contaminated site, before testing it on the real thing, taking it to a field at a Navy training area known to have extremely high PFAS levels.
The researchers ran a “push-pull” test, injecting the carbon into the ground, creating an underground treatment zone where PFAS bind as groundwater flows through the net, then pumping the water back out to measure how much of the PFAS made it through. In their tests, the PFAS concentrations dropped from more than 50,000 nanograms per liter to tktk, below detection limits, within 10 months. Importantly, the carbon net captures both long-chain and short-chain PFAS. This is a big deal for the potential cleanup of these forever chemicals because short-chain PFAS are harder to remove, yet are becoming increasingly common as manufacturers move away from older compounds.
Just as important from an economic standpoint is that, according to the team’s analysis, the long-term operating costs of this carbon-based approach would be less than half those of the existing PFAS remedies. And because the system would exist underground, it would require little maintenance.
“This study shows that we can create an effective treatment zone underground that dramatically reduces PFAS levels with far lower long-term costs,” Matt Simcik, a professor in the School of Public Health and co-author of the study, shared in a statement. “The effectiveness of this method, combined with the fact that the system requires very little ongoing maintenance, makes this a promising option for real-world cleanup efforts. For communities facing PFAS contamination, this represents a major step forward toward practical, sustainable technologies that can protect drinking water and reduce long-term exposure risks.”
It’s critical to note that this isn’t a silver bullet — at least not yet. The researchers are clear that more work is needed to understand how long underground carbon remains effective and how it could perform under different soil conditions. But the study does offer some good news and a potentially practical path forward in the fight against forever chemicals. And, on a similarly impactful note, it shows just how important it is that we work on this issue together.
”The project shows the importance of partnerships between practitioners, government, and academia,” William Arnold, a professor in the College of Science and Engineering, said. “The expertise, experience, and insight of the individuals who made up the team were needed for this lab-to-field project to succeed.”
The world has entered a new era of ‘water bankruptcy,’ U.N. report says
Researchers say this is not merely a temporary crisis, but a permanent failure that requires rethinking the world’s approach to water scarcity.
Iran’s Lake Urmia, once the largest lake in the Middle East, has dramatically shrunk due to prolonged drought, the damming of rivers feeding the lake, and extensive groundwater extraction in the surrounding area. (MORTEZA AMINOROAYAYI/Middle East Images/AFP via Getty Images)
Climate change, pollution and decades of overuse have pushed the world into a state of “water bankruptcy,” leaving essential sources of fresh water irreparably damaged and billions of people without enough water to meet their basic needs, United Nations experts declared on Tuesday.
In a sweeping report from United Nations University (UNU), the international agency’s research arm, scientists compared humanity to a person plunging into financial ruin. Not only does the world overspend its annual water “income” — the renewable flows that come from rain and snow — but it has also exhausted the long-term “savings” stored in underground aquifers, glaciers and ecosystems. At the same time, people are allowing pollution from human waste, agriculture and industrial operations to contaminate the dwindling fresh water that remains — like someone setting fire to the last few dollars in their wallet.
Signs of this emergency are alarming and abundant, said lead author Kaveh Madani, director of the UNU Institute for Water, Environment and Health. More than half of the world’s large lakes are shrinking. Roughly 70 percent of underground aquifers are in long-term decline. Large-scale droughts have become more frequent and pervasive, costing an average of $307 billion annually. Some 4.4 billion people face water scarcity for at least one month a year.
Madani and his colleagues argue that it’s not sufficient to refer to the situation as “water stress” or a “water crisis” — language often used by the U.N. and other international institutions — because the challenge will not go away anytime soon.
Human activities have already caused irreversible damage to many of the systems that generate, regulate and store fresh water, the report says. Rising temperatures, driven mostly by the burning of fossil fuels, have altered precipitation patterns and increased the rate of evaporation from landscapes. Deforestation and development have destroyed the ecosystems that filter and clean rainwater. Overextraction is causing the collapse of subterranean aquifers that store groundwater, reducing their capacity to become recharged. And melting mountain glaciers, which accumulated over centuries or millennia, will not grow back in a human lifetime.
“What appears on the surface as a crisis is, in fact, a new baseline,” the report authors write. “Some losses are now unavoidable, and the central task is to prevent further irreversible damage while reorganizing the system around a smaller hydrological budget.”
Existing policies are too narrowly focused on improving sanitation and drinking water and helping industries to become incrementally more efficient, the report says. Ahead of an upcoming United Nations water conference in the United Arab Emirates, it calls on leaders to declare a “global water bankruptcy” and adopt a new approach to managing the world’s dwindling supply of safe water. Otherwise, it warns, the world will slide deeper into a future of food shortages, disease outbreaks and water-fueled conflict.Ask The Post AIDive deeper
Madani, who was born in Tehran, became convinced of the need for a new approach to water management after watching a decades-old black-and-white video about shortages in the Iranian capital. The narrator referred to the situation as a “crisis” — the same language being used now to describe the multiyear drought that has threatened Tehran’s water supply and prompted President Masoud Pezeshkian to contemplate evacuating the city.
“How long can we call something like this crisis?” Madani said. “A crisis means a shock — it’s an anomaly that must be addressed urgently, but still you have hopes that the baseline can be restored.”
“I think it’s a big lie if you’re communicating to the public that this is a temporary situation,” he added. What Iran — and the world — are truly facing is “a postcrisis situation of failure.”
The water shortages in Iran — which experts have linked to human-caused climate change as well as surging demand and mismanagement of limited resources — have led to rationing, power cuts and increased food prices. The economic strain helped fuel the mass protest movement currently gripping the country, which in turn has prompted a brutal crackdown by government forces.
These issues increasingly affect countries of all sizes and income levels, said Melissa Scanlan, an environmental law expert and director of the Center for Water Policy at the University of Wisconsin at Milwaukee, who did not contribute to the report.
Major urban areas — from Cape Town, South Africa to Chennai, India to Mexico City — have teetered on the brink of “day zero” events, when water supplies fall so low that millions of people’s taps run dry. Pervasive droughts have caused spikes in the prices of foods such as Mediterranean olive oil and California vegetables, while saltwater contamination from rising seas has caused billions of dollars in damage to rice paddies and fruit farms in Vietnam. Large hydropower dams from Zambia to Nevada have seen reservoir levels fall so low they lose their ability to produce electricity. And some places have pumped so much water from their aquifers that their land is sinking — damaging infrastructure and making these areas more vulnerable to floods.Ask The Post AIDive deeper
“The global scope of the report is useful in showing repeat patterns,” Scanlan said. “It’s not just the Southern Hemisphere, it’s not just the Middle East. There is something larger at play in terms of how we’re treating water across the world.”
The report also shows how water problems are already wreaking economic and political havoc. Western U.S. states are locked in a years-long battle over the dwindling Colorado River. Egypt, Sudan and Ethiopia are at odds over a massive new dam on a major tributary of the Nile. Research shows that undocumented migration from Mexico to the United States increases amid warming-fueled droughts.
“Lack of water means lack of food,” Madani said. “It means famine, unemployment, chaos, revolution.”
A lot of this geopolitical turmoil comes down to what Madani calls a “mismatch between water availability and water consumption.” The laws, contracts and treaties that govern water use — such as the century-old compact determining allocation of the Colorado River — were based on a climate that no longer exists, she said. Farmers, cities and industrial water users trade blame over who is taking more than their fair share, without acknowledging that the overall pie has shrunk. Typical measures to address shortfalls, such as drilling deeper wells or diverting more water from rivers, can end up making the problem worse.
Much the way a company filing Chapter 11 bankruptcy must restructure operations, renegotiate contracts and create a new plan to pay debts, the world should reassess how much water is actually available and prioritize among competing claims, the U.N. report says. In some cases, that might involve limiting new development in water-stressed cities or restricting the growth of water-intensive industries. World leaders must also protect the forests, wetlands and other ecosystems that pay a crucial role in Earth’s water cycle.
The biggest challenges — and the biggest opportunity for change — lie in the agriculture sector, which accounts for 70 percent of humanity’s water usage, said Rabi Mohtar, a hydrologist who leads the Water-Energy-Food Nexus Research Group at Texas A&M University.
Governments may need to impose restrictions on irrigation and groundwater pumping or require farmers to shift to less-thirsty crops, he said. They should also implement regulations to prevent pesticides, fertilizers and other forms of agricultural runoff from polluting the shrinking water supply.
Mohtar, who was not involved in the U.N. report, expressed skepticism about the rhetorical value of declaring “water bankruptcy.” He worried that the terminology might discourage people from taking action, because it sends the message that humanity has already failed.
But he agreed with the basic premise that people have drastically exceeded the planet’s capacity to produce clean, fresh water.
“The time when we have abundance is over,” Mohtar said. “I would like to see accountability to every single drop.”
Rethinking the world’s approach to managing water will have far-reaching economic and social consequences, the U.N. report acknowledges. Arid nations might need to import food rather than trying to grow it themselves. Farmers in areas that can no longer support agriculture may need to pursue other livelihoods. If changes aren’t implemented in a manner that is equitable and inclusive, the report said, the world’s poorest and most vulnerable people will inevitably suffer the most.
Yet Madani emphasized that addressing the world’s water challenges will yield “co-benefits” in other areas. Restoring wetlands can help reduce dust storms, improving air quality and public health. Techniques to boost farmland’s ability to retain water also helps the soils absorb more carbon.
“In a fragmented world, water might be an excuse for bringing people together,” he said.
The world has entered an era of “global water bankruptcy” that is harming billions of people, a UN report has declared.
The overuse and pollution of water must be tackled urgently, the report’s lead author said, because no one knew when the whole system could collapse, with implications for peace and social cohesion.
All life depends on water but the report found many societies had long been using water faster than it could be replenished annually in rivers and soils, as well as over-exploiting or destroying long-term stores of water in aquifers and wetlands.
This had led to water bankruptcy, the report said, with many human water systems past the point at which they could be restored to former levels. The climate crisis was exacerbating the problem by melting glaciers, which store water, and causing whiplashes between extremely dry and wet weather.
Prof Kaveh Madani, who led the report, said while not every basin and country was water bankrupt, the world was interconnected by trade and migration, and enough critical systems had crossed this threshold to fundamentally alter global water risk.
The result was a world in which 75% of people lived in countries classified as water-insecure or critically water-insecure and 2 billion people lived on ground that is sinking as groundwater aquifers collapse.
Conflicts over water had risen sharply since 2010, the report said, while major rivers, such as the Colorado, in the US, and the Murray-Darling system, in Australia, were failing to reach the sea, and “day zero” emergencies – when cities run out of water, such as in Chennai, India – were escalating. Half of the world’s large lakes had shrunk since the early 1990s, the report noted. Even damp nations, such as the UK, were at risk because of reliance on imports of water-dependent food and other products.
“This report tells an uncomfortable truth: many critical water systems are already bankrupt,” said Madani, of the UN University’s Institute for Water, Environment and Health. “It’s extremely urgent [because] no one knows exactly when the whole system would collapse.”
About 70% of fresh water taken by human withdrawals was used for agriculture, but Madani said: “Millions of farmers are trying to grow more food from shrinking, polluted or disappearing water sources. Water bankruptcy in India or Pakistan, for example, also means an impact on rice exports to a lot of places around the world.” More than half of global food was grown in areas where water storage was declining or unstable, the report said.
Madani said action to deal with water bankruptcy offered a chance to bring countries together in an increasingly fragmented world. “Water is a strategic, untapped opportunity to the world to create unity within and between nations. It is one of the very rare topics that left and right and north and south all agree on its importance.”https://interactive.guim.co.uk/datawrapper/embed/rksLJ/1/?dark=false
The UN report, which is based on a forthcoming paper in the peer-reviewed journal Water Resources Management, sets out how population growth, urbanisation and economic growth have increased water demand for agriculture, industry, energy and cities. “These pressures have produced a global pattern that is now unmistakable,” it said.
In some of the world’s most densely populated river basins, including the Indus, Yellow, and Tigris-Euphrates, the rivers were periodically drying up before reaching the ocean. “In many basins, the ‘normal’ to which crisis managers once hoped to return has effectively vanished,” the report said. Lakes were also shrinking, from Lake Urmia, in Iran, to the Salton Sea, in the US, and Lake Chad. Wildlife suffered as well as people, as humans “steal” water from nature, Madani said
The over-exploitation of groundwater was causing cities to subside around the world, with Rafsanjan, in Iran, sinking by 30cm a year; Tulare, in the US, by about 28cm a year, and Mexico City by about 21cm a year. Jakarta, Manila, Lagos and Kabul were other major cities affected. Among the most visible signs of this water bankruptcy, the report said, were the 700 sinkholes peppering the heavily farmed Konya plain in Turkey.
Cities, such as Tehran, Cape Town, São Paulo and Chennai, had all faced day zero water crises, the report noted, while the number of water-related conflicts around the world had risen from 20 in 2010 to more than 400 in 2024.skip past newsletter promotion
Humanity was also slashing the amount of water available by destroying natural stores, such as wetlands, and polluting waterways. Wetlands equal in size to the entire European Union had been erased in the past five decades, the report said.
The report calls for a fundamental reset of how water is protected and used around the world. This would include cutting the rights and claims to withdraw water to match today’s degraded supply, and transforming water-intensive sectors, such as agriculture and industry, via changes in crops, more efficient irrigation and less wasteful urban systems. The report emphasises support for communities whose livelihoods must change.
“Water bankruptcy management requires honesty, courage and political will,” said Madani. “We cannot rebuild vanished glaciers or reinflate acutely compacted aquifers. But we can prevent further losses, and redesign institutions to live within new hydrological limits.”
Tshilidzi Marwala, UN undersecretary general, said: “Water bankruptcy is becoming a driver of fragility, displacement and conflict. Managing it fairly is now central to maintaining peace, stability and social cohesion.”
The challenge of sustainable water management around the world was very real, said Prof Albert Van Dijk, at the Australian National University who was not part of the UN report, although, he added, he preferred the description of collapse, or systemic failure, over bankruptcy.
A recent water report led by Van Dijk highlighted the increasingly erratic climate. “Increased variability is as much a problem as scarcity,” he said. “Sometimes there’s more water available overall, but it increasingly arrives in bursts, at the wrong place and at the wrong time. This makes management genuinely harder. For example, dam reservoir levels need to be kept low to mitigate floods but high to ensure supply during droughts.”
Dr Jonathan Paul, at Royal Holloway, University of London, said: “The report lays bare humankind’s mistreatment of water [which] threatens the viability of ‘the water cycle’ as a concept.
“The elephant in the room, which is mentioned explicitly only once, is the role of massive and unequal population growth in driving so many of the manifestations of water bankruptcy,” he said. “Addressing this growth would be more useful than tinkering with outdated, non-inclusive, and top-down water resource management frameworks.”
Water quality has been closely related to human health 1 ever since John Snow linked a cholera outbreak in London to contaminated water in 1855.2Vibriocholerae in water still plays a big role in the annual 1.4-4.3 million cholera cases that continue to occur globally. 3 The SARS-CoV-2 virus, which caused the COVID-19 pandemic, also enters the water cycle, as some COVID-19 patients shed the virus with their stool. 4 Although SARS-CoV-2 has been detected in wastewater, and in surface water receiving untreated wastewater, 5 so far there has been no evidence for presence of viable or infectious virus particles in wastewater, or for water as a transmission source. 6 Instead, the European Union launched a study, coordinated by its Joint Research Council and linked to the World Water Quality Alliance, to explore the potential of wastewater-based virus remnants as a sentinel monitoring concept.
But pathogens are not the only problem. Water is contaminated in a number of other ways that can threaten human health. The toxic compound arsenic is widely present in groundwater and can lead to skin, vascular and nervous system disorders, and cancer. 7 Recent estimates show that 94-220 million people are exposed to high arsenic concentrations in groundwater. 8 Similarly, fluoride, nitrate, heavy metals, and salinity in (ground)water pose human health risks.
Biotoxins formed by some cyanobacteria are a particular nuisance because bloom-forming species accumulate at the water surface, requiring closure of bathing sites and drinking water intakes. 9 As well, a large number of organic micropollutants coming from manufacturing and agriculture pose a health risk to the population. 10These organic micropollutants can have a variety of impacts, such as disruption of endocrine, reproductive and immune systems. They can also cause cancer and diabetes as well as thyroid and behavioural problems . 11
More recently recognized contaminants influencing human health include antimicrobial resistant microorganisms (AMR), microplastics 12or nanomaterials. AMR are a concern worldwide 13because infections from them are often difficult to treat. Although the role of water in the spread of AMR is not yet quantified, its importance has been recognized. 14
The potential health risks from microplastics seem obvious, but knowledge of the extent to which they affect human health is limited. 15And, though recent focus has largely been on the marine realm, UNEP will soon publish guidance on monitoring and addressing plastics in freshwater. 16
Water quality is related to human health through exposure. People are exposed to water in many different ways, depending on their location, livelihood, culture, wealth, gender etc. The most common exposure ways can be summarized as drinking, bathing, ingestion during domestic use, eating irrigated vegetables, rice (or rice products) or aquatic plants (such as water spinach), eating contaminated fish and shellfish, and skin contact. These exposure pathways highlight that the quality of ground, surface and coastal waters is relevant to human health.
In an earlier assessment, Snapshot of the World’s Water Quality, 17faecal coliforms were the contaminant included to represent human-health impacts. The assessment concluded that the rural population at risk of health problems, which is defined as those in contact with water contaminated with high concentrations of faecal coliforms, could be up to hundreds of millions of people in Latin America, Africa and Asia. 18While this was an important realization, faecal coliform concentrations do not usually correlate very well with pathogen concentrations, as they can grow in the water body, 19and many more contaminants can have human-health impacts. Therefore, this current assessment incorporates more water quality variables and exposure routes to assess the impact of water quality on human health.
Results
To evaluate the direct and indirect impacts of water quality on human health, we developed a non-exhaustive overview (see Table 3.1). This showed that there are a large number of direct and indirect links between water quality and human health, as well as interrelations between water quality variables, their sources, state, impacts and response. For example, pathogens and nitrate have to some extent the same sources and, therefore, potentially similar response options. But quantitative evidence for the links between water quality and human health are still largely lacking at continental or larger scales.
The global freshwater quality database GEMStat has data for a number of contaminants, but these data vary in space and time. For example, faecal coliform data are available for 6,451 stations across the world, while Escherichia coli data are available from 3,790 stations in North America, South America, Japan, and New Zealand. Data for Salmonella are available for 62 stations along rivers in Europe, but only for a few years in the early 1990s. For arsenic, many heavy metals, nutrients and organic micropollutants some data are available in GEMStat. Here we do not evaluate these data, because they are scattered and recent data for health are scarce. Instead, we report on potential data analyses that have been performed.
Table 3.1The influence of water quality on human health. This list is non-exhaustive, as no detailed literature has been performed. The colour coding is blue for GEMStat or other large-scale databases; red for remote sensing; yellow for modelling; and green for a combination of GEMStat and modelling. Dark colours are for surface water, light colours for groundwater.
Throughout the fall, Harvard Chan faculty will share evidence-based recommendations on urgent public health issues facing the next U.S. administration. Ronnie Levin, instructor in the Department of Environmental Health, offered her thoughts on policies that could address contamination in the country’s drinking water supply.
Q: Why is drinking water quality a pressing public health issue?
A: The U.S. has arguably the best and most reliable drinking water in the world, and that’s because we’ve spent a lot of money and time getting it in that shape. On the other hand, our drinking water is not risk-free. It’s not perfectly safe—it can contain lead, nitrate, PFAS, arsenic, and uranium, as examples. In addition, there are racial and ethnic disparities in contaminant exposures, so not everybody gets the same quality of drinking water.
Q: What are the biggest challenges facing the next administration around improving drinking water quality?
A: A hundred years ago, we sunk a lot of money into water treatment and infrastructure, but then we stopped putting in that kind of investment. Now our water systems are severely aging and deteriorated, and we haven’t continued to maintain the older ones. And when we build new ones, they’re not always as well designed as the old ones.
In addition, science has moved on—we’ve found things in our drinking water that we thought weren’t bad, like PFAS, that turn out to be biologically active at very low levels. Lead, arsenic, and nitrate cause health effects at lower levels than we knew when we set the standards decades ago. We now need to catch up.
Ronnie Levin. Photo: Kent Dayton Q: What are your top policy recommendations to address drinking water quality?
A: There’s been recent progress toward reducing lead in drinking water. On Oct. 8, the Environmental Protection Agency (EPA) announced a rule that requires all lead pipes in U.S. water systems to be replaced within the next decade, lowers the current level for taking action to reduce lead exposure from 15 to 10 parts per billion, and also implements several other policies to reduce exposure to lead from drinking water. If the rule is implemented and enforced, millions of people will have cleaner, safer water. Importantly, it will particularly enhance environmental protection among disadvantaged and low-income populations, which have been disproportionately impacted by lead-contaminated water.
There are several other contaminants I’d like to see the government address. PFAS are a class of thousands of chemicals that are in all kinds of consumer products. We don’t even know all of them, because industry keeps tweaking them to be different and cheaper, and industry doesn’t have to report how they get used. There are PFAS everywhere, contaminating water, soil, air, and food, and they build up in people and the environment over time.
We don’t know a lot about the thousands of different PFAS because it takes years to do studies, and we haven’t known about them for that many years. But research so far has suggested that PFAS are associated with a host of biological changes, even at very low levels. PFAS exposure has been linked with many adverse health outcomes, such as decreased immune system function, thyroid disease, and kidney and testicular cancers.
The EPA recently set regulations for six PFAS chemicals, ones that we know are the easiest to measure and are associated with numerous health effects. Many people are researching PFAS, but industry is constantly altering the formulations for new and different applications, and so there’s no way to stop this train. But the EPA’s efforts are really good news.
Another issue that the EPA needs to address is revising the standard for arsenic in drinking water. We’ve known that arsenic is a poison for a really long time, and that’s actually what makes it so useful—we use it in chemotherapies, pesticides, and herbicides. It has a lot of other useful applications, like in paints and glassmaking. But arsenic has negative health effects across the board, including cardiovascular harms, liver damage, neurotoxicity, and reproductive toxicity.
The arsenic limit for drinking water—which was set in 2001 at 10 parts per billion—is probably an order of magnitude too high. It was looking like the EPA might propose lowering the arsenic standard in the next few years, but with the change in administration, that likelihood is looking dim. There’s a lot of resistance from industry and water utilities, but I think taking action on arsenic will be easier than regulating so many different types of PFAS, which is going to take a lot longer.
As for the EPA’s nitrate standard, it is dangerously high, and violations of the nitrate standard are the most common health-based violations of drinking water standards.
In general, the EPA is behind in keeping the drinking water standards up to date with the current scientific literature. Setting standards is a laborious process and, in addition, there is tremendous pushback from the “drinking water industry”—public water systems, which are often cities themselves, or semi-governmental agencies like the Massachusetts Water Resources Authority, which oversees water systems in the Boston metropolitan area. There are 50,000 active public water systems in the U.S., and there is a lot of complaining from those systems about the difficulty and expense of meeting stricter standards.
Q: What’s the evidence supporting those recommendations?
A: My colleagues and I wrote a 2023 review article about the exposure risks of a wide range of drinking water contaminants, including PFAS, arsenic, and more. In that article, we cited a number of studies linking these chemicals to health harms:
A 2023 meta-analysis of over a dozen different studies found that several types of PFAS may lower the body’s ability to produce antibodies after receiving vaccines, particularly for diphtheria, rubella, and tetanus. A 2022 meta-analysis of over 100 rodent and human epidemiological studies identified a link between PFAS exposure and liver injury. A 2013 study followed almost 4,000 individuals for around two decades, and found that higher arsenic levels in urine were associated with increased mortality from lung, prostate, and pancreatic cancers. A 2015 meta-analysis of over a dozen studies identified a link between arsenic exposure and adverse pregnancy outcomes and infant mortality. A 2021 study analyzed nationwide data collected by the Centers for Disease Control and Prevention, finding that an increased level of arsenic in urine was associated with heart disease mortality. Q: What do you hope can be accomplished to improve drinking water quality in the next four years?
A: Addressing both PFAS and arsenic will be difficult and expensive, and also take a lot of political will. The Supreme Court has tied the EPA’s hands through decisions such as eliminating the Chevron deference, which called for deferring to federal agencies for their judgments where federal law is silent or unclear, and the 2023 Sackett v. EPA case, which limited the agency’s power to regulate wetlands and waterways. The EPA can’t just issue regulations, it has to get laws passed through Congress, which is much harder to do. It used to be that the courts would defer to the EPA, but now the agency is going to have to make a much stronger case for regulations.
Regarding lead, now that the Biden administration has finalized the new lead pipe rule the government needs to make sure that the rule is implemented and enforced.
We have to regain a commitment to protecting human health and the environment, and clean drinking water should be a top priority. We have a lot of hard work to do.
WASHINGTON – New data released by the Environmental Protection Agency shows an additional 6.5 million Americans have drinking water contaminated by the toxic “forever chemicals” known as PFAS. It brings the total number of people at risk of drinking this contaminated tap water to about 165 million across the U.S.
“It is impossible to ignore the growing public health crisis of PFAS exposure. It’s detectable in nearly everyone and it’s found nearly everywhere, including the drinking water for a huge segment of the population,” saidDavid Andrews, Ph.D., acting chief science officer at the Environmental Working Group.
“The documented extent of PFAS contamination of the country’s water supply highlights the enormous scale of contamination,” he added.
The EPA’s new findings come from tests of the nation’s drinking water supply conducted as part of the Fifth Unregulated Contaminant Monitoring Rule, or UCMR 5, which requires U.S. water utilities to test drinking water for 29 individual PFAS compounds.
The EPA has said it will roll back limits on four PFAS in drinking water, leaving those chemicals unregulated. It plans to only retain standards for the two most notorious chemicals, PFOA and PFOS. These maximum contaminant levels or MCLs, set enforceable standards for the amount of contaminants allowed in drinking water.
Even with keeping the PFOA and PFOS MCLs in place, rolling back the four other limits will make it harder to hold polluters responsible and ensure clean drinking water.
In addition, the EPA’s plan to reverse the four science-based MCLs likely contradicts an anti-backsliding provision in the Safe Drinking Water Act. That law requires any revision to a federal drinking water standard “maintain, or provide for greater, protection of the health of persons.”
“It’s worrying to see the EPA renege on its commitments to making America cleaner and safer, especially as it ignores its own guidelines to do so,” said Melanie Benesh, EWG’s vice president for government affairs.
Widespread PFAS pollution
The Trump administration’s PFAS standards rollback could grant polluters unchecked freedom to release toxic forever chemicals into U.S. waterways, endangering millions of Americans.
EWG estimates nearly 30,000 industrial polluters could be discharging PFAS into the environment, including into sources of drinking water. Restrictions on industrial discharges would lower the amount of PFAS ending up in drinking water sources.
“Addressing the problem means going to the source. For PFAS, that’s industrial sites, chemical plants and the unnecessary use of these chemicals in consumer products,” said Andrews.
Health risks of PFAS exposure
PFAS are toxic at extremely low levels. They are known as forever chemicals because once released into the environment, they do not break down and can build up in the body. The Centers for Disease Control and Prevention has detected PFAS in the blood of 99 percent of Americans, including newborn babies.
For over 30 years, EWG has been dedicated to safeguarding families from harmful environmental exposures, holding polluters accountable and advocating for clean, safe water.
“Clean water should be the baseline,” Andrews said, “The burden shouldn’t fall on consumers to make their water PFAS-free. While there are water filters that can help, making water safer begins with ending the unnecessary use of PFAS and holding polluters accountable for cleanup.”
For people who know of or suspect the presence of PFAS in their tap water, a home filtration system is the most efficient way to reduce exposure. Reverse osmosis and activated carbon water filters can be extremely effective at removing PFAS.
EWG researchers tested the performance of 10 popular water filters to evaluate how well each reduced PFAS levels detected in home tap water.
###
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.
PFAS, also known as “forever chemicals,” have emerged as a serious environmental and public health threat due to their persistence and widespread contamination. These man-made chemicals, widely utilized in consumer and industrial products since World War II, are now linked to alarming levels of contamination in drinking water supplies and health risks ranging from cancers to liver toxicity to reduced fertility.
Following decades of litigation, the U.S. Environmental Protection Agency in 2024 finally set legally enforceable levels for six PFAS chemicals in drinking water, requiring public water systems to monitor for the substances, report findings to customers, and take steps to reduce contamination. However, those regulations were partially rolled back in May 2025.
In this Q&A, two Yale experts delve into the challenges posed by PFAS and potential solutions for reducing exposure and contamination. Vasilis Vasiliou is Department Chair and Susan Dwight Bliss Professor of Epidemiology at Yale School of Public Health (YSPH). Robert Bilott is an environmental attorney and serves as a lecturer with the YSPH Department of Environmental Health Sciences. Bilott’s story and landmark case against chemical giant DuPont were recounted in his book, “Exposure: Poisoned Water, Corporate Greed, and One Lawyer’s Twenty-Year Battle Against DuPont,” and were the basis for the 2019 motion picture “Dark Waters,” starring Mark Ruffalo.
This interview was edited and condensed for clarity.
What are PFAS?
BILOTT: PFAS stands for per- and polyfluoroalkyl substances. They are a completely man-made family of chemicals created around the time of World War II. These chemicals, formed by artificially connecting carbon and fluorine, are known for their strength, stain resistance, grease protection, and water resistance. They are used in a wide variety of products, and there are now estimates of up to 14,000 different PFAS compounds.
Why are PFAS called ‘forever chemicals?’
VASILIOU: PFAS are often called ‘forever chemicals’ because they contain an exceptionally strong carbon-fluorine bond, which makes them highly resistant to breakdown. As a result, they persist in the environment for decades or longer—in water, soil, and even living organisms. Their environmental and biological persistence means they can accumulate over time, raising long-term concerns for ecosystems and public health.
What consumer or industrial products contain PFAS?
BILOTT: PFAS have been used in an incredible array of consumer and commercial products since the 1940s. Common products containing PFAS include non-stick cookware, carpeting, clothing, fast food wrappers and packaging, computer chips, toilet paper, and waterproof cosmetics. Keywords like stain-resistant, waterproof, grease-resistant, and non-stick often indicate the presence of PFAS. These chemicals were not listed on ingredient lists or labels, and many companies were unaware they were using them.
What are the known health risks associated with PFAS?
VASILIOU: PFAS are linked to various cancers such as kidney, testicular, and liver cancer, as well as liver toxicity. There is a rising incidence of early-onset cancers, like colon and liver cancer, in younger individuals, potentially due to developmental exposure. Developmental and reproductive effects of PFAS include low birth weight, accelerated puberty, reduced fertility, and pregnancy-induced hypertension, with possible epigenetic changes that might contribute to early-onset cancers. PFAS also impair the immune system, reducing vaccine effectiveness and potentially increasing susceptibility to infections like COVID-19. Additionally, PFAS exposure is linked to various metabolic effects such as obesity, type 2 diabetes, cardiovascular disease, reduced kidney function, high cholesterol, colitis, and neurodegenerative issues in children.
By some estimates, 90% of drinking water in the U.S. contains PFAS. How did that happen?
BILOTT: PFAS contamination in drinking water primarily comes from aqueous film-forming foam, or AFFF—the firefighting foam that was developed during the Vietnam War to extinguish petroleum-based fires. This foam contains high concentrations of C-8 PFAS chemicals known as PFOA and PFOS that have been widely used by military organizations, airports, and fire stations globally since the 1960s. The people buying and using it were not informed about its PFAS content and were misled about its safety, which led to widespread environmental contamination.
Has a safe level for PFAS chemicals been identified?
BILOTT: No one has identified a safe level of PFAS chemicals. Companies like 3M and DuPont set internal safety guidelines for their employees decades ago, but this information was withheld from government agencies and scientists until much later. Studies have revealed that PFAS are persistent, bioaccumulative, and toxic, affecting multiple organ systems and potentially reducing vaccine effectiveness. The EPA has set very low drinking water standards, aiming for no more than four parts per trillion and ideally zero for PFOA and PFOS, which are now recognized as human carcinogens.
VASILIOU: PFAS chemicals are not metabolized by the body, unlike many other environmental contaminants. Because they resist breakdown and are only slowly excreted, they accumulate in human tissues—especially in the blood, liver, and kidneys—over time. This bioaccumulation contributes to a range of toxic effects, including immunotoxicity, endocrine disruption, and increased risk of kidney and testicular cancer. Given their extreme persistence and potential for harm even at very low levels, efforts to establish safe exposure limits increasingly aim toward zero.
Can the human body repair damage caused by PFAS?
VASILIOU: The human body has some ability to repair tissue damage, but with PFAS, this process is complicated by the chemicals’ persistence. PFAS remain in the body for years and can interfere with normal repair mechanisms by promoting inflammation, oxidative stress, and immune dysfunction. Even if some tissues, like the liver, can regenerate, ongoing internal exposure means that damage may continue, making full recovery difficult—especially with chronic or high-level exposures.
Are any PFAS chemicals regulated?
BILOTT: In 2024, the first federal nationwide regulations for PFAS chemicals were adopted by the EPA, setting drinking water standards and declaring two C-8 PFAS as hazardous under federal Superfund law. The process took decades, with companies pushing back and fighting regulation in courts. States like New Jersey, Minnesota, and Connecticut have also moved forward with regulations, which are facing legal challenges from manufacturers. In Europe, proposed global bans on PFAS face significant opposition due to economic impacts.
What technologies exist to remove PFAS from drinking water?
VASILIOU: Activated carbon and reverse osmosis are the primary technologies to remove PFAS, though reverse osmosis is very expensive for individual homes. Yale engineers are working on innovative solutions, such as membranes and methods to break down PFAS chemicals.
Who is going to pay for cleaning up PFAS contamination?
BILOTT: Our law firm represents hundreds of cities seeking compensation from companies like 3M and DuPont, who created the chemicals. These cases are part of the aqueous film-forming foam (AFFF) multidistrict litigation in South Carolina. Recently, significant settlements totaling over $14 billion from companies like 3M, DuPont, BASF, and Tyco have been reached to help public water systems clean up PFAS. The federal government has allocated $10 billion for this purpose but that is taxpayer money. We are working to ensure the responsible companies pay for the cleanup.
How does someone know if PFAS is present in their drinking water or consumer products?
BILOTT: It’s not always easy. For public water systems, sampling is starting to be required and information may be available in quarterly reports to customers. But many districts haven’t started testing yet. The Environmental Working Group created an interactive map showing where testing has occurred and what the levels are. For consumer products, there’s a lot less information. PFAS were not listed on ingredient labels or material safety data sheets, and even manufacturers might not have known they were using PFAS. Some groups are now testing products for PFAS, and products labeled with buzzwords like waterproof, stain-resistant, non-stick, and grease-proof might contain PFAS. Consumer demand has led some companies to commit to PFAS-free products, but definitions and detection levels vary so that is causing mass confusion in the market.
What can the average person do about the PFAS problem?
VASILIOU: Individuals can reduce their PFAS exposure by avoiding products such as older non-stick cookware, water-resistant clothing, stain-proof textiles, and certain cosmetics that may contain PFAS. It’s also important to be informed about your drinking water—use certified filters that are effective against PFAS and consult local or state resources for water quality information, including bottled water when available. Beyond personal choices, civic engagement plays a powerful role. Raising awareness, supporting legislation, and demanding transparency from manufacturers and regulators can drive meaningful, large-scale change
BILOTT: An individual can make a huge difference by standing up, speaking out, and demanding change. It may take a while, but as you see in the story of “Dark Waters,” individuals speaking out are having a huge impact. Laws are being proposed and passed to restrict these chemicals. Some of the biggest companies on the planet are now committing to getting out of PFAS. That only happened by individuals saying ‘we don’t want this.’
What is Yale doing?
Yale is committed to making the university a healthy and productive place to live, work, and study. We are reducing the amount of harmful chemicals on campus through healthy furniture standards to reduce the amount of chemicals of concern in the materials we purchase to furnish our buildings. The Yale School of Public Health is leading groundbreaking research into the human health impacts of PFAS, analyzing their role in cancer cell migration, liver damage, and pregnancy loss. The Yale School of Engineering and Applied Sciences is developing technologies to separate and destroy PFAS at water treatment facilities and other locations.
WASHINGTON – U.S. Environmental Protection Agency (EPA) Administrator Lee Zeldin announced the agency will keep the current National Primary Drinking Water Regulations (NPDWR) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), which set nationwide limits for these “forever chemicals” in drinking water. The agency is committed to addressing Per- and Polyfluoroalkyl substances (PFAS) in drinking water while following the law and ensuring that regulatory compliance is achievable for drinking water systems.
“The work to protect Americans from PFAS in drinking water started under the first Trump Administration and will continue under my leadership,” saidEPA Administrator Zeldin. “We are on a path to uphold the agency’s nationwide standards to protect Americans from PFOA and PFOS in their water. At the same time, we will work to provide common-sense flexibility in the form of additional time for compliance. This will support water systems across the country, including small systems in rural communities, as they work to address these contaminants. EPA will also continue to use its regulatory and enforcement tools to hold polluters accountable.”
As part of this action, EPA is announcing its intent to extend compliance deadlines for PFOA and PFOS, establish a federal exemption framework, and initiate enhanced outreach to water systems, especially in rural and small communities, through EPA’s new PFAS OUTreach Initiative (PFAS OUT). This action would help address the most significant compliance challenges EPA has heard from public water systems, members of Congress, and other stakeholders, while supporting actions to protect the American people from certain PFAS in drinking water.
Paired with effluent limitations guidelines (ELGs) for PFAS and other tools to ensure that polluters are held responsible, EPA’s actions are designed to reduce the burden on drinking water systems and the cost of water bills, all while continuing to protect public health and ensure that the agency is following the law in establishing impactful regulations such as these.
EPA is also announcing its intent to rescind the regulations and reconsider the regulatory determinations for PFHxS, PFNA, HFPO-DA (commonly known as GenX), and the Hazard Index mixture of these three plus PFBS to ensure that the determinations and any resulting drinking water regulation follow the legal process laid out in the Safe Drinking Water Act.
Regulatory Protection with Flexibility and Cost Savings
On April 10, 2024, EPA announced the final National Primary Drinking Water Regulation, including standards for PFOA and PFOS. At that time, EPA established legally enforceable levels for these PFAS in drinking water and gave public water systems until 2029 to comply with the Maximum Contaminant Levels (MCLs).
To allow drinking water systems more time to develop plans for addressing PFOA and PFOS where they are found and implement solutions, EPA plans to develop a rulemaking to provide additional time for compliance, including a proposal to extend the compliance date to 2031. EPA plans to issue a proposed rule this fall and finalize this rule in the Spring of 2026. Aligned with the agency’s intent to provide additional compliance time for water systems, EPA encourages states seeking primacy for implementing the PFAS drinking water regulation to request additional time from EPA to develop their applications. At the same time, EPA will support the U.S. Department of Justice in defending ongoing legal challenges to the PFAS National Primary Drinking Water Regulation with respect to PFOA and PFOS.
“EPA has done the right thing for rural and small communities by delaying implementation of the PFAS rule. This commonsense decision provides the additional time that water system managers need to identify affordable treatment technologies and make sure they are on a sustainable path to compliance. NRWA greatly appreciates this reasonable and flexible approach, and we look forward to partnering with the agency’s PFAS OUTreach Initiative to help ensure water systems have the resources and support they need,” said National Rural Water Association CEO Matthew Holmes.
“ASDWA supports EPA’s proposed approach to the PFAS regulation to extend the compliance date for systems by an additional two years. With the current compliance date of 2029, states and water systems are struggling with the timeframes to complete the pilot testing, development of construction plans, and building the necessary treatment improvements. EPA’s proposed extension of the compliance date and increased technical assistance will address the number of systems that would be out of compliance in 2029 due to not being able complete all of these tasks on time,” said Association of State Drinking Water Administrators Executive Director Alan Roberson.
Enhancing Communication and Outreach
To enhance engagement on addressing PFAS, EPA will launch PFAS OUT to connect with every public water utility known to need capital improvements to address PFAS in their systems, including those EPA has identified as having PFOA and PFOS levels above EPA’s MCL. EPA will share resources, tools, funding, and technical assistance to help utilities meet the federal drinking water standards. PFAS OUT will ensure that no community is left behind as we work to protect public health and bring utilities into compliance with federal drinking water standards. PFAS OUT will engage utilities, technical assistance providers and local, State, Tribal, and Territorial leaders to develop effective, practical solutions where they are needed most.
EPA will continue to offer free water technical assistance (WaterTA) that provides services to water systems to improve their drinking water and help communities access available funding. EPA’s WaterTA initiatives work with water systems nationwide to identify affordable solutions to assess and address PFAS, including PFOA and PFOS. Services offered to utilities include water quality testing, development of technical plans, operator training support, designing public engagement and outreach strategies, and support for accessing federal funding opportunities.
Holding Polluters Accountable
Drinking water systems are passive receivers of PFOA and PFOS. Polluters can contaminate the surface waters or aquifers that these systems rely on to provide the drinking water to their communities. As announced by Administrator Zeldin, EPA intends to take a number of actions to reduce the prevalence of PFAS in the environment, including in sources of drinking water. Progress reducing concentrations of PFAS in drinking water sources can substantially reduce the cost burden for water systems and reduce the cost of living for the communities they serve.
A Record of Leadership
Administrator Zeldin’s leadership on PFAS dates back to his time in Congress, where he was a founding member of the PFAS Congressional Taskforce and a strong supporter of the PFAS Action Act, legislation to provide funding to support local communities cleaning up PFAS-contaminated water systems. He was, and remains, a staunch advocate for protecting Long Islanders and all Americans from contaminated drinking water.
In the process of developing and taking action on a number of these items, Administrator Zeldin personally heard from members of Congress on passive receiver issues where local water utilities will foot the bill for contamination and pass those costs onto consumers. This mindset and the need for a polluter pays model has guided a lot of the work to be done at EPA in the future.
Background
On April 28, 2025, Administrator Zeldin announced a long list of actions to combat PFAS contamination that included in part the designation of an agency lead for PFAS, the development of ELGs for certain PFAS to reduce discharges to waterways including upstream of drinking water systems, and initiatives to engage with Congress and industry to establish a clear liability framework that ensures passive receivers and consumers are protected. This list is the first, not the last, of all decisions and actions EPA will be taking to address PFAS over the course of the Trump Administration. There will be more to come in the future across EPA’s program offices to help communities impacted by PFAS contamination.
During President Trump’s first term, EPA convened a two-day National Leadership Summit on PFAS in Washington, D.C. that brought together more than 200 federal, state, and local leaders from across the country to discuss steps to address PFAS. Following the Summit, the agency hosted a series of visits during the summer of 2018 in communities directly impacted by PFAS. EPA interacted with more than 1,000 Americans during community engagement events in Exeter, New Hampshire, Horsham, Pennsylvania, Colorado Springs, Colorado, Fayetteville, North Carolina, and Leavenworth, Kansas, as well as through a roundtable in Kalamazoo, Michigan, and events with tribal representatives in Spokane, Washington.
In 2019, the Trump EPA announced the PFAS Action Plan. This historic Plan responded to extensive public interest and input the agency received and represented the first time EPA built a multi-media, multi-program, national communication and research plan to address an emerging environmental challenge like PFAS. EPA’s Action Plan identified both short-term solutions for addressing these chemicals and long-term strategies that will help provide the tools and technologies states, tribes, and local communities need to provide clean and safe drinking water to their residents and to address PFAS at the source—even before it gets into the water.
EPA supports water systems in reducing PFAS and emerging contaminants (EC) in drinking water through a range of funding resources. Federal funding opportunities include the Drinking Water State Revolving Fund (DWSRF) program, the EC Small or Disadvantaged Communities (EC-SDC) grant program, and funding resources, like EPA’s Water Infrastructure Finance and Innovation Act (WIFIA) program, that can be leveraged to provide supplemental, flexible, low-cost credit assistance to public and private borrowers.
From fluoride to “forever chemicals,” drinking water has been in the spotlight this year. In a Q&A, Yale epidemiologist Nicole Deziel discusses the water we drink today — and what’s on tap for the future.
Aug 13, 2025
7 min read
By Meg Dalton
(Illustration by Michael S. Helfenbein)
Listen to this story
8:33
In 1945, Grand Rapids, Michigan, made history — as the first city in the world to add small amounts of fluoride to its public water supply. At the time, studies showed communities with higher levels of natural fluoride in water had better dental health. Water fluoridation is now practiced in about 25 countries around the world, including Spain, Malaysia, and the United States. In the U.S., approximately 63% of the population drinks fluoridated water.
Low levels of fluoride, a naturally occurring mineral, can be found in many sources of drinking water due to natural processes like the weathering of rocks and human activities like manufacturing. However, there’s growing debate over whether additional fluoride should be introduced to drinking water. This year, states including Utah and Florida have banned the use of fluoride in public water systems, and federal officials have called for more states to follow suit.
Nicole Deziel is an associate professor of epidemiology (environmental health sciences) and co-director of the Yale Center for Perinatal, Pediatric and Environmental Epidemiology at the Yale School of Public Health. In an interview, she explains the benefits and risks of fluoride, how “forever chemicals” and climate change impact water quality, and how we can monitor the water we drink.
Nicole Deziel
The interview has been edited for length and clarity.
What are the benefits of fluoride? Are there any potential risks?
Nicole Deziel: Fluoride can strengthen our bones and teeth enamel, and the strengthening of the enamel prevents cavities. But too much of it can damage our bones and enamel in a process called fluorosis, and it can potentially have neurological effects as well. Fluoridation of the public water supply can help address disparities in dental insurance and access to dental care.
Finding the right amount where the benefits outweigh the risks is key. The U.S. Public Health Service recommends a fluoride concentration of 0.7 mg/L [parts per million] in drinking water. The World Health Organization recommends a limit of 1.5 mg/L, while the U.S. Environmental Protection Agency sets a limit of 4 mg/L. Newer evidence of more subtle neurological effects is prompting reexamination of these target levels and limits.
Why are we seeing some states ban the use of fluoride in public water systems? Why are some people suspicious of it?
Deziel: There’s a long history of controversy about fluoride, including urban legends and conspiracy theories. For some people, it may seem counterintuitive to add a chemical that may have some toxic properties to make our water safer. However, we do this with chlorine as well. Chlorine is toxic at high levels and can form harmful byproducts, but we add it to drinking water to disinfect it and kill bacteria and pathogens to make our water safe to drink. We’re often doing these kinds of tradeoffs in environmental health and public health. In addition, misinformation and distrust of science could all be contributing to us revisiting this [the fluoridation of water].
Finding the right amount [of fluoride] where the benefits outweigh the risks is key.
Nicole Deziel
However, there’s been some new data that should prompt us to reexamine fluoride. There have been a few recent studies that have shown that fluoride exposure is linked to lower IQ levels in children where fluoride levels are above some of the target levels. Some in the dental community have raised concerns about how the data in those studies are being interpreted. Given these concerns, it is important that experts across disciplines collectively re-examine the latest evidence on fluoride’s risks and benefits to ensure the public and policymakers receive clear, evidence-based guidance.
Let’s move from fluoride to so-called “forever chemicals,” also known as PFAS. What are PFAS, and why are they called “forever chemicals”?
Deziel: PFAS, or per- and polyfluoroalkyl substances, are commonly referred to as “forever chemicals” due to their persistence in the environment as well as human bodies. They’re molecules that have chains of carbon and fluorine, and the carbon-fluorine bond is the strongest chemical bond known.
Their properties have made PFAS very desirable in many consumer products like Teflon pans, stain-resistant and water-resistant clothing and textiles, food packaging, and more. They’re also in firefighting foam.
According to some estimates, 90% of drinking water in the U.S. contains PFAS. How did happen, and what impact do PFAS have on our health?
Deziel: This happens for a few reasons, such as improper disposal of PFAS at manufacturing sites and the use of firefighting foams at airports and military bases. But PFAS are also in household products, many of which can go down the drain and be introduced into our environment.
PFAS have been linked to a variety of adverse health problems, including endocrine disruption, cancer, reproductive effects, decreased effects on our immune system, decreased efficacy of vaccines, and more.
Last year, the U.S. set the first-ever national limits on PFAS. Now, some of those regulations are being delayed or reconsidered. How are limits set for contaminants like PFAS?
Deziel: The Environmental Protection Agency sets maximum contaminant levels for drinking water under the Safe Drinking Water Act. When they set them, they’re allowed to consider not just public health but technological or economic feasibility. It took about 20 years just to get the PFAS standards passed, even though we’ve known about these issues for decades. This is a very slow and inefficient process, and the standards are not keeping pace with the science. So, it’s frustrating that the few new standards set may not even move forward.
In recent years, we’ve also seen several extreme weather events, from wildfires and floods to intense heat and droughts. How does climate change threaten the safety of our drinking water?
Deziel: Climate change can impact our drinking water in many ways. First, increasing intense droughts can affect our water supplies and lead to water scarcity. With wildfires, we often focus on the smoke and the immediate damage, but once the fires have been addressed, there are concerns about all the fire-retardant chemicals that are deposited into our soils and waterways. Plus, wildfires require a lot of water. Rising sea levels can create saltwater intrusion into freshwater sources. Floods and storms can release chemicals into our waterways and impact our water infrastructure overall. So there are many ways our changing climate and extreme weather can affect drinking water.
What can people like you and me do to monitor — and even improve — the quality of the water we drink?
Deziel: In public health, we talk about a hierarchy of controls. So, the best would be to have evidence-based drinking water standards that reflect the best science, and that would be because not everybody has the time and resources to research different strategies or purchase different filters.
However, if someone wanted to reduce their exposures to chemicals, there are several different filtering devices that are available. The most common is the charcoal, or activated carbon, filter. These can remove some chemicals including chlorine, some metals, some organic contaminants, and some but not all PFAS. They can be installed for the whole house, under the sink, or directly on the faucet. Reverse osmosis filters, which push water through a special membrane, are more effective at removing a much wider range of chemicals, but they’re more expensive. Countertop and pitcher-style filters are other options. They use gravity to pass water through a carbon cartridge. They’re generally more affordable, and while they don’t remove as many contaminants as in-line systems, they offer some protection and may be a good starting point for some households.
People may be tempted to turn to bottled water. However, many brands of bottled water are just tap water that’s been run through extra purification steps (spring water and mineral water are exceptions). This additional treatment can mean the water is very clean, but bottled water comes with significant downsides. In the U.S., only a tiny fraction of the millions of plastic bottles we use actually get recycled, with most polluting streets, rivers, and oceans. Producing those bottles uses petroleum and releases greenhouse gases, adding to climate change. Moreover, single-use plastic bottles can release endocrine-disrupting chemicals called phthalates as well as tiny plastic particles known as microplastics, especially if left in sunlight and heat.
Water is life. Yet, as the world population mushrooms and climate change intensifies droughts, over 2 billion people still lack access to clean, safe drinking water. By 2030, water scarcity could displace over 700 million people. From deadly diseases to famines, economic collapse to terrorism, the global water crisis threatens to sever the strands holding communities together. This ubiquitous yet unequally distributed resource underscores the precarious interdependence binding all nations and ecosystems and shows the urgent need for bold collective action to promote global water security and avert the humanitarian, health, economic, and political catastrophes that unchecked water stress promises.
—
The global water crisis refers to the scarcity of usable and accessible water resources across the world. Currently, nearly 703 million people lack access to water – approximately 1 in 10 people on the planet – and over 2 billion do not have safe drinking water services. The United Nations predicts that by 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity. With the existing climate change scenario, almost half the world’s population will be living in areas of high water stress by 2030. In addition, water scarcity in some arid and semi-arid places will displace between 24 million and 700 million people. By 2030, water scarcity could displace over 700 million people.
In Africa alone, as many as 25 African countries are expected to suffer from a greater combination of increased water scarcity and water stress by 2025. Sub-Saharan regions are experiencing the worst of the crisis, with only 22-34% of populations in at least eight sub-Saharan countries having access to safe water.
Water security, or reliable access to adequate quantities of acceptable quality water for health, livelihoods, ecosystems, and production has become an urgent issue worldwide.
This crisis has far-reaching implications for global health, food security, education, economics, and politics. As water resources dwindle, conflicts and humanitarian issues over access to clean water will likely increase. Climate change also exacerbates water scarcity in many parts of the world. Addressing this complex and multifaceted crisis requires understanding its causes, impacts, and potential solutions across countries and communities.
The global water crisis stems from a confluence of factors, including growing populations, increased water consumption, poor resource management, climate change, pollution, and lack of access due to poverty and inequality.
The world population has tripled over the last 70 years, leading to greater demand for finite freshwater resources. Agricultural, industrial, and domestic water usage have depleted groundwater in many regions faster than it can be replenished. Agriculture alone accounts for nearly 70% of global water withdrawals, often utilizing outdated irrigation systems and water-intensive crops.Climate change has significantly reduced renewable water resources in many parts of the world. Glaciers are melting, rainfall patterns have shifted, droughts and floods have intensified, and temperatures are on the rise, further exacerbating the crisis.
Baseline water stress measures the ratio of total water withdrawals to available renewable water supplies. Image: United Nations (2019).
In many less developed nations, lack of infrastructure, corruption, and inequality leave large populations without reliable access to clean water. Women and children often bear the burden of travelling distances to fetch water for households. Contamination from human waste, industrial activities, and agricultural runoff also threaten water quality and safety.
Water scarcity poses risks to health, sanitation, food production, energy generation, economic growth, and political stability worldwide. Conflicts over shared water resources are likely to intensify without concerted global action.
Case Study: Water Crisis in Gaza
The water crisis in Gaza represents one of the most severe cases of water scarcity worldwide. The small Palestinian territory relies almost entirely on the underlying coastal aquifer as its source of freshwater. However, years of excessive pumping far exceed natural recharge rates. According to the UN, 97% groundwater does not meet World Health Organization (WHO) standards for human consumption due to high salinity and nitrate levels.
The pollution of Gaza’s sole freshwater source stems from multiple factors. Rapid population growth contaminated agricultural runoff, inadequate wastewater treatment, and saltwater intrusion due to over-extraction have rendered the aquifer unusable.
In June 2007, following the military takeover of Gaza by Hamas, the Israeli authorities significantly intensified existing movement restrictions, virtually isolating the Gaza Strip from the rest of the occupied Palestinian territory (oPt), and the world. The blockade imposed by Israeli Authority also severely restricts infrastructure development and humanitarian aid.
The water crisis has devastated Gazan agriculture, caused widespread health issues, and crippled economic growth. Many citizens of Gaza have to buy trucked water of dubious quality, as the public network is unsafe and scarce. The United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) reports that this water can cost up to 20 times more than the public tariff, with some households spending a third of their income or more on water. Long-term solutions require increased water supplies, wastewater reuse, desalination, and better resource management under conflict.
According to a 2022 report by the WHO and UNICEF’s Joint Monitoring Programme (JMP), 344 million people in sub-Saharan Africa lacked access to safely managed drinking water, and 762 million lacked access to basic sanitation in 2020. WaterAid, a non-governmental organization, explains that water resources are often far from communities due to the expansive nature of the continent, though other factors such as climate change, population growth, poor governance, and lack of infrastructure also play a role. Surface waters such as lakes and rivers evaporate rapidly in the arid and semi-arid regions of Africa, which cover about 45% of the continent’s land area. Many communities rely on limited groundwater and community water points to meet their water needs, but groundwater is not always a reliable or sustainable source, as it can be depleted, contaminated, or inaccessible due to technical or financial constraints. A 2021 study by UNICEF estimated that women and girls in sub-Saharan Africa collectively spend about 37 billion hours a year collecting water, which is equivalent to more than 1 billion hours a day.The 2023 UN World Water Development Report emphasizes the importance of partnerships and cooperation for water, food, energy, health and climate security in Africa, a region with diverse water challenges and opportunities, low water withdrawals per capita, high vulnerability to climate change, and large investment gap for water supply and sanitation.
In the Meatu District in Shinyanga, an administrative region of Tanzania, water most often comes from open holes dug in the sand of dry riverbeds and it is invariably contaminated.
Water security in Africa is low and uneven, with various countries facing water scarcity, poor sanitation, and water-related disasters. Transboundary conflicts over shared rivers, such as the Nile, pose additional challenges for water management.
However, some efforts have been made to improve water security through various interventions, such as community-based initiatives, irrigation development, watershed rehabilitation, water reuse, desalination, and policy reforms. These interventions aim to enhance water availability, quality, efficiency, governance, and resilience in the face of climate change. Water security is essential for achieving sustainable development in Africa, as it affects numerous sectors, such as agriculture, health, energy, and the environment.
Other Countries with Water Shortages
Water scarcity issues plague many other parts of the world beyond Gaza and Africa. Several examples stand out:
Iraq faces severe water stress impacting agriculture and public health. The Tigris and Euphrates Rivers have dwindled because of upstream damming and climate change. Water distribution is inefficient and wasteful.
Indiagrapples with extensive groundwater depletion, shrinking reservoirs and glaciers, pollution from agriculture and industry, and tensions with Pakistan and China over shared rivers. Monsoons are increasingly erratic with climate change.
Projections show India will be under severe water stress by the end of the decade. Image: WRI.
While the specifics differ, recurrent themes include unsustainable usage, climate change, pollution, lack of infrastructure, mismanagement, poverty, transboundary conflicts, and population growth pressures. But resources often exist; the challenge lies in equitable distribution, cooperation, efficiency, and sustainable practices. Multiple approaches must accommodate local conditions and transboundary disputes.
Water scarcity poses a grave threat to global security on multiple fronts.
First, it can incite conflicts within and between nations over access rights. History contains many examples of water wars, and transboundary disputes increase the risk today in arid regions like the Middle East and North Africa.
Second, water shortages undermine food security. With agriculture consuming the greatest share of water resources, lack of irrigation threatens crops and livestock essential for sustenance and livelihoods. Food price spikes often trigger instability and migrations.
Third, water scarcity fuels public health crises, leading to social disruptions. Contaminated water spreads diseases like cholera and typhoid. Poor sanitation and hygiene due to water limitations also increase illness. The Covid-19 pandemic underscored the essential nature of water access for viral containment.
Finally, water shortages hamper economic growth and worsen poverty. Hydroelectricity, manufacturing, mining, and other water-intensive industries suffer. The World Bank estimates that by 2050, water scarcity could cost some regions 6% of gross domestic product (GDP), entrenching inequality. Climate migration strains nations. Overall, water crises destabilize societies on many levels if left unaddressed.
Solutions and Recommendations
Tackling the global water crisis requires both local and international initiatives across infrastructure, technology, governance, cooperation, education, and funding.
First, upgrading distribution systems, sewage treatment, dams, desalination, watershed restoration, and irrigation methods could improve supply reliability and quality while reducing waste. Community-based projects often succeed by empowering local stakeholders.
Second, emerging technologies like low-cost water quality sensors, affordable desalination, precision agriculture, and recyclable treatment materials could help poorer nations bridge infrastructure gaps. However, funding research and making innovations affordable remains a key obstacle.
Third, better governance through reduced corruption, privatization, metering, pricing incentives, and integrated policy frameworks could improve efficiency. But human rights must be protected by maintaining affordable minimum access.
Fourth, transboundary water-sharing treaties like those for the Nile and Mekong Rivers demonstrate that diplomacy can resolve potential conflicts. But political will is needed, along with climate change adaptation strategies.
Fifth, education and awareness can empower conservation at the individual level. Behaviour change takes time but can significantly reduce household and agricultural usage.
Finally, increased financial aid, public-private partnerships, better lending terms, and innovation prizes may help nations fund projects. Cost-benefit analyses consistently find high returns on water security investments.
In summary, sustainable solutions require combining new technologies, governance reforms, education, cooperation, and creative financing locally and globally.
Conclusion
The global water crisis threatens the well-being of billions of people and the stability of nations worldwide. Key drivers include unsustainable usage, climate change, pollution, lack of infrastructure, poverty, weak governance, and transboundary disputes. The multiple impacts span public health, food and energy security, economic growth, and geopolitical conflicts.
While daunting, this crisis also presents opportunities for innovation, cooperation, education, and holistic solutions. With wise policies and investments, water security can be achieved in most regions to support development and peace. But action must be accelerated on both global and community levels before the stresses become overwhelming. Ultimately, our shared human dependence on clean water demands that all stakeholders work in unison to create a water-secure future.
:max_bytes(150000):strip_icc():format(webp)/Scientists-Underground-Fix-PFAS-Drinking-Water-FT-DGTL0126-8a7f79e48b49459390a775a27583088e.jpg)
GET WET! 